U.S. patent application number 17/538835 was filed with the patent office on 2022-03-17 for systems for controlling silica dust during hydraulic fracturing operations.
The applicant listed for this patent is SIERRA DUST CONTROL, LLC. Invention is credited to Cody Baker, Kim R. Smith.
Application Number | 20220080479 17/538835 |
Document ID | / |
Family ID | |
Filed Date | 2022-03-17 |
United States Patent
Application |
20220080479 |
Kind Code |
A1 |
Baker; Cody ; et
al. |
March 17, 2022 |
SYSTEMS FOR CONTROLLING SILICA DUST DURING HYDRAULIC FRACTURING
OPERATIONS
Abstract
A system for controlling dust during hydraulic fracturing
operations includes a manifold having a plurality of ports for
capturing dust when negative air pressure is applied to the
manifold. A support frame positions the manifold above a piece of
hydraulic fracturing equipment receiving sand from a sand
source.
Inventors: |
Baker; Cody; (Tatum, TX)
; Smith; Kim R.; (Tatum, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SIERRA DUST CONTROL, LLC |
Tatum |
TX |
US |
|
|
Appl. No.: |
17/538835 |
Filed: |
November 30, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15164577 |
May 25, 2016 |
11185900 |
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17538835 |
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14862354 |
Sep 23, 2015 |
9630223 |
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15164577 |
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14527868 |
Oct 30, 2014 |
9168482 |
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14862354 |
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14178782 |
Feb 12, 2014 |
8881749 |
|
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14527868 |
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13769456 |
Feb 18, 2013 |
9162261 |
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14178782 |
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62291419 |
Feb 4, 2016 |
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International
Class: |
B08B 15/00 20060101
B08B015/00; B65G 69/18 20060101 B65G069/18; B65G 67/24 20060101
B65G067/24; E21B 43/267 20060101 E21B043/267 |
Claims
1. A system for controlling dust during hydraulic fracturing
operations comprising: a manifold having at least one port for
capturing dust when negative air pressure is applied to the
manifold; a support frame including a plurality of spaced-apart
support frame members positioning the manifold above a piece of
frac sand handling equipment that is configured to receive frac
sand from an external frac sand source, the piece of frac sand
handling equipment comprising one of a conveyor, a bin of a
hydraulic fracturing blender, or a tub of a hydraulic fracturing
blender; wherein each support frame member of the support frame
includes an upper section connected between a pair of spaced-apart
vertical portions, the pair of vertical portions being adapted to
straddle the piece of frac sand handing equipment, and wherein a
lower end of each respective vertical portion is connected to, and
supported by, a respective individual base configured to rest on
the ground, wherein each respective individual base is directly
connected to the lower end of the respective vertical portion and
is not directly connected to any other individual base, any other
vertical portion, or any other support frame member of the support
frame; wherein each respective vertical portion is directly
connected to the respective individual base and the respective
upper section, and is not directly connected to any other
individual base, any other vertical portion or any other support
frame member of the support frame; and wherein the individual
bases, vertical portions and upper section are unconnected to the
piece of frac sand handling equipment; wherein the support frame
further comprises a plurality of spaced-apart longitudinal members
directly connected between the upper sections of adjacent support
frame members and unconnected to the piece of frac sand handling
equipment, the plurality of spaced-apart longitudinal members being
the only portions of the support frame longitudinally connecting
adjacent support frame members; and a cover supported by the
support frame for enclosing the piece of frac sand handling
equipment and an air inlet connected to the at least one port of
the manifold, the cover including at least one aperture for
receiving sand from the external frac sand source.
2. The system of claim 1, wherein each respective individual base
is configured to have an enlarged cross-sectional area relative to
the respective vertical portion.
3. The system of claim 2, wherein each individual base is
configured as a cylinder.
4. The system of claim 1, wherein the at least one port of the
manifold further comprises a conduit extending from the manifold to
the air inlet of the at least one port.
5. The system of claim 4, wherein the conduit extending from the
manifold is flexible for positioning the air inlet adjacent the
piece of frac sand handling equipment.
6. The system of claim 4, wherein the manifold is positioned
outside the support frame and outside the cover, and wherein the
cover includes a second aperture for passing the conduit
therethrough from the manifold on the outside of the cover to the
air inlet enclosed by the cover.
7. The system of claim 1, wherein the manifold is positioned inside
the support frame and enclosed within the cover.
8. The system of claim 1, wherein a first portion of the manifold
is positioned to be outside the cover and a second portion of the
manifold is positioned to be enclosed by the cover.
9. The system of claim 1, further comprising a remote conduit
extending from the manifold to a remote source of dust for
capturing dust from the remote source when negative air pressure is
applied to the manifold, wherein the remote source of dust is not
enclosed by the cover.
10. The system of claim 9, wherein the remote source of dust is one
a frac sand storage container, a frac sand transportation trailer
or a frac sand lifting conveyor system.
11. The system of claim 1, wherein at least one port further
comprises an air flow control mechanism for controlling air flow
through the port.
12. A system for controlling dust during hydraulic fracturing
operations comprising: a support structure including a plurality of
spaced-apart support frame members; a manifold having a plurality
of ports positioned by the support structure above a piece of frac
sand handling equipment receiving frac sand from a frac sand
source, the piece of frac sand handling equipment comprising one of
a conveyor, a bin of a hydraulic fracturing blender, or a tub of a
hydraulic fracturing blender; wherein each support frame member of
the support structure includes an upper section connected between a
pair of spaced-apart vertical legs, the pair of legs being adapted
to straddle the piece of frac sand handing equipment, and wherein a
lower end of each respective leg is connected to, and supported by,
a respective individual base configured to rest on the ground,
wherein each respective individual base is directly connected to
the lower end of the respective leg and is not directly connected
to any other individual base, any other leg, or any other support
frame member of the support structure, wherein each respective leg
is directly connected to the respective individual base and the
respective upper section and is not directly connected to any other
individual base, any other leg or any other support frame member of
the support structure, and wherein the individual bases, legs and
upper section are unconnected to the piece of frac sand handling
equipment; wherein the support structure further comprises a
plurality of spaced-apart longitudinal members directly connected
between the upper sections of adjacent support frame members and
unconnected to the piece of frac sand handling equipment, the
plurality of spaced-apart longitudinal members being the only
portions of the support structure longitudinally connecting
adjacent support frame members; and an enclosure supported by the
support structure and enclosing at least a portion of the piece of
frac sand handling equipment, wherein each port of the manifold is
coupled to a conduit extending through a space within the enclosure
towards the piece of frac sand handling equipment and having an
inlet for capturing dust contained within the enclosure when
negative air pressure is applied to the manifold, wherein the
enclosure includes a sidewall with at least one aperture
therethrough for receiving the frac sand from the frac sand source
external to the enclosure.
13. The system of claim 12, wherein the manifold is disposed within
the enclosure.
14. The system of claim 12, wherein the manifold is suspended from
the support structure.
15. The system of claim 12, wherein the manifold is disposed
outside of the enclosure and at least one of the plurality of
conduits extends through a wall of the enclosure such that the
inlet of the at least one of the plurality of conduits is disposed
within the enclosure.
16. The system of claim 12, wherein the manifold is positioned
along a top portion of the support structure.
17. The system of claim 12, wherein the manifold is positioned
along a side portion of the support structure.
18. The system of claim 12, wherein the external frac sand source
comprises a trailer having a trailer conveyor, an end of the
trailer conveyor extending through the sidewall of the enclosure to
discharge frac sand to the frac sand handling equipment.
19. The system of claim 12, wherein the external frac sand source
comprises a silo having a chute, an end of the chute extending
through the sidewall of the enclosure to discharge frac sand to the
frac sand handling equipment.
20. The system of claim 12, further comprising a remote conduit
extending from the manifold to a remote source of dust for
capturing dust from the remote source when negative air pressure is
applied to the manifold, wherein the remote source of dust is not
enclosed by the enclosure.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. patent
application Ser. No. 15/164,577, filed May 25, 2016, entitled
SYSTEMS AND METHODS FOR CONTROLLING SILICA DUST DURING HYDRAULIC
FRACTURING OPERATIONS USING AN IMPROVED MANIFOLD, issued as U.S.
Pat. No. 11,185,900 on Nov. 30, 2021 (Atty. Dkt. No. SIER01-00011),
which is a Continuation-in-part of U.S. patent application Ser. No.
14/862,354, filed on Sep. 23, 2015, entitled SYSTEMS AND METHODS
FOR CONTROLLING SILICA DUST DURING HYDRAULIC FRACTURING OPERATIONS,
issued as U.S. Pat. No. 9,630,223 on Apr. 25, 2017 (Atty. Dkt. No.
SIER01-00008), which is a Continuation of U.S. patent application
Ser. No. 14/527,868, filed on Oct. 30, 2014, entitled SYSTEMS AND
METHODS FOR CONTROLLING SILICA DUST DURING HYDRAULIC FRACTURING
OPERATIONS, issued as U.S. Pat. No. 9,168,482 on Oct. 27, 2015
(Atty. Dkt. No. SIER01-00005), which is a Divisional of U.S. patent
application Ser. No. 14/178,782, filed Feb. 12, 2014, entitled
SYSTEMS AND METHODS FOR CONTROLLING SILICA DUST DURING HYDRAULIC
FRACTURING OPERATIONS, issued as U.S. Pat. No. 8,881,749 on Nov.
11, 2014 (Atty. Dkt. No. SIER01-00003), which is a Continuation of
U.S. patent application Ser. No. 13/769,456, filed Feb. 18, 2013,
entitled SYSTEMS AND METHODS FOR CONTROLLING SILICA DUST DURING
HYDRAULIC FRACTURING OPERATIONS, issued as U.S. Pat. No. 9,162,261
on Oct. 20, 2015 (Atty. Dkt. No. SIER01-00002). U.S. patent
application Ser. No. 15/164,577 claims benefit of U.S. Provisional
Patent Application No. 62/291,419, filed on Feb. 4, 2016, entitled
SYSTEMS AND METHODS FOR CONTROLLING DUST DURING HYDRAULIC
FRACTURING OPERATIONS USING AN IMPROVED MANIFOLD (Atty. Dkt. No.
SIER01-00010). This application is related to U.S. patent
application Ser. No. 16/216,871, filed Dec. 11, 2018, entitled
SILICA DUST CONTROLS FOR HYDRAULIC FRACTURING OPERATIONS, issued as
U.S. Pat. No. 11,104,531 on Aug. 31, 2021 (Atty. Dkt. No.
SIER01-00014). All the foregoing, including patent application Ser.
Nos. 16/216,871, 15/164,577, 14/862,354, 14/527,868, 14/178,782,
13/769,456 and 62/291,419, are incorporated by reference herein in
their entirety.
TECHNICAL FIELD
[0002] The present invention relates in general to hydraulic
fracturing, and in particular to systems and methods for
controlling silica dust during the handling of frac sand.
BACKGROUND
[0003] Hydraulic fracturing ("tracing") is a well known technique
for releasing oil and natural gas from underground reservoirs
within rock formations having a limited permeability. For example,
fracing is often used to release oil and natural gas, such as
natural gas or oil, from shale formations.
[0004] Fracing is a well completion technique performed after the
drilling of the wellbore, which in the case of releasing natural
gas from shale, is commonly a horizontal wellbore, although
occasionally the wellbore is vertical. Fracing fluid, which is
primarily water and chemicals that form a viscous gel, is pumped
into the well to create fractures within the surrounding rock. The
viscous gel carries a "proppant" into the fractures, such that when
the pumping stops, the fractures remain substantially open and
allow the oil and natural gas to escape into the wellbore.
[0005] One typical proppant is "frac sand." Frac sand is normally
high purity silica sand with grains having a size and shape capable
of resisting the crushing forces applied during the closing of the
fractures when the hydraulic force provided by the pumping is
removed. However, given that frac sand contains a high proportion
of silica, the loading, transportation, and unloading of frac sand
presents significant safety challenges.
[0006] The United States Occupational Safety and Health
Administration ("OSHA") lists silica as a carcinogen. In
particular, the exposure and inhalation of silica dust has been
linked to silicosis, which is an irreversible lung disorder
characterized by inflammation and scarring of the upper lobes of
the lungs. The best, and perhaps only way, to reduce or eliminate
the threat of silicosis is to carefully control worker exposure to
silica dust.
[0007] OSHA lists a number of different ways to limit worker
exposure to silica dust, including limiting worker time at a
worksite, limiting the number of workers at a worksite, watering
roads and other worksite areas, enclosing points where silica dust
is released, and requiring workers to wear respirators. These
techniques do not, at least on their own, provide a complete
solution to the problem of controlling silica dust. Furthermore,
these existing techniques, while commendable, are nonetheless
burdensome, time-consuming, inefficient, and impractical.
SUMMARY
[0008] One representative embodiment of the principles of the
present invention is a system for controlling dust during hydraulic
fracturing operations, which includes a manifold having a plurality
of ports for capturing dust when negative air pressure is applied
to the manifold. A support structure positions the manifold above a
piece of hydraulic fracturing equipment receiving sand from a frac
sand source.
[0009] Another representative embodiment is a system for
controlling dust during hydraulic fracturing operations, which
includes a support structure and a manifold positioned by the
support structure above a piece of frac sand handling equipment
receiving frac sand from a frac sand source. An enclosure supported
by the support structure encloses at least a portion of the piece
of frac sand handling equipment. At least one conduit in fluid
communication with the manifold has an inlet for capturing dust
contained within the enclosure when negative air pressure is
applied to the manifold.
[0010] A further exemplary embodiment of the present principles is
a frac sand handling system including frac sand handling equipment,
and a support structure. An enclosure is supported by the support
structure and encloses at least a portion of the frac sand handling
equipment including a point at which frac sand is received by the
frac sand handling equipment. A manifold is positioned by the
support structure above the frac sand handling equipment. The
manifold includes a plurality of ports for capturing dust when
negative air pressure is applied to the manifold, with at least one
of the ports adapted to capture dust generated around the point at
which frac sand is received by the frac sand handling
equipment.
[0011] The present inventive principles advantageously provide for
efficient and flexible systems and methods for collecting the
silica dust generated during the offload of frac sand from a frac
sand source, such as a sand transport and storage trailer, a
vertical sand mover, or one or more containers positioned directly
above the lateral conveyor. Among other things, by positioning the
manifold above the lateral handling equipment (e.g., blender bin
and/or tub, t-belt, or dragon tail) the overall profile of the
enclosure and manifold system becomes more compact. As a result,
the amount of dust control system equipment on or near the ground
can be reduced, which reduces tripping hazards, reduces clutter,
and increases accessibility to both the dust control system and the
associated frac sand handling equipment.
[0012] The manifold, support structure, and enclosure can be
configured to control dust generated in and around various pieces
of frac sand handling equipment such as lateral conveyors
(t-belts), angled lifting conveyors (dragon tails), and blenders,
as well as different combinations of those pieces of equipment.
[0013] The support structure allows the manifold to either be
suspended from the support structure using a cable or strap or
supported at a point on the support structure itself. The support
structure may be free-standing such that other equipment within the
frac sand handling and dust control system can be moved or
reconfigured without the need to move or reconfigure the manifold,
support structure, and/or enclosure.
[0014] The support structure also allows the manifold to be
positioned inside or outside of the enclosure that contains dust
generated during operation of the frac sand handling equipment. In
embodiments in which the manifold is positioned inside the
enclosure, air flow into the manifold can be achieved through a
simple aperture through the manifold wall, through a fitting
adapted to connect with a flexible conduit, with or without the
flexible conduit attached, or through an extended fitting or rigid
conduit.
[0015] The application of these principles improves the efficiency
and flexibility of the frac sand offloading process by allowing
increased worker time at the worksite and/or for more workers to be
present at the worksite at one time, reducing the need for watering
of worksite areas and the enclosure of points where silica dust is
released, reducing the need for respirator wear, and decreasing the
amount of silica dust intake by the engines of nearby vehicles and
equipment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] For a more complete understanding of the present invention,
and the advantages thereof, reference is now made to the following
descriptions taken in conjunction with the accompanying drawings,
in which:
[0017] FIG. 1 is a perspective diagram of a representative frac
sand transportation and unloading system including a frac sand
silica dust control system according to a preferred embodiment of
the principles of the present invention;
[0018] FIG. 2 is a plan view diagram of the frac sand
transportation and unloading system of FIG. 1, which emphasizes the
airflow paths through the frac sand silica dust control system;
[0019] FIG. 3 is a plan view diagram of the frac sand
transportation and unloading system of FIG. 1, which generally
indicates the locations of particular structures of the frac sand
silica dust control subsystem shown in more detail in FIGS.
4-6;
[0020] FIG. 4A is a diagram showing in further detail the pneumatic
connections between the inlets of the silica dust control unit and
the manifolds of FIG. 1;
[0021] FIG. 4B is a diagram showing in further detail the direct
airflow path between the silica dust control unit and the silica
dust control conduit subsystem servicing one selected trailer of
FIG. 1;
[0022] FIG. 4C is a diagram showing in further detail the pneumatic
connection between a selected manifold and the silica dust control
conduit subsystem serving another selected trailer of FIG. 1;
[0023] FIG. 4D is a diagram showing in further detail the pneumatic
connections between a selected manifold and the silica dust capture
hose controlling silica dust generated during the operation of a
corresponding trailer discharge conveyor shown in FIG. 1;
[0024] FIG. 4E is a diagram showing in further detail the pneumatic
connections between a selected manifold and the silica dust capture
hoses controlling silica dust generated by the system discharge
conveyor of FIG. 1;
[0025] FIG. 5A is a diagram showing in further detail a selected
silica dust capture hose controlling silica dust generated by the
discharge of frac sand from the tank of representative trailer to
the base of the corresponding trailer discharge conveyor shown in
FIG. 1;
[0026] FIG. 5B is a diagram showing in further detail a selected
silica dust capture hose controlling silica dust generated by the
discharge of frac sand from the outlet of a corresponding
representative trailer conveyor to the lateral transfer conveyor
section of FIG. 1;
[0027] FIG. 5C is a diagram showing the hoses controlling silica
dust generated during the movement of sand by the upwardly angled
conveyor section of FIG. 1 to a point above the bin of the blender
of FIG. 1, along with the silica dust capture hose controlling
silica dust generated during the discharge of sand into the blender
bin from the conveyor section spout;
[0028] FIG. 6A is a diagram showing in further detail the pneumatic
connections of the silica dust control conduit subsystem of a
representative one of the trailers of FIG. 1;
[0029] FIG. 6B is a diagram showing in further detail one of the
T-fittings interconnecting the air conduits of the silica dust
control conduit subsystem shown in FIG. 6A;
[0030] FIG. 6C is a diagram showing one of the end fittings
terminating the air conduits of the silica dust control conduit
subsystem shown in FIG. 6A;
[0031] FIG. 6D is a diagram showing the four-way fitting
interconnecting the air conduits of the silica dust control
subsystem of one particular trailer with the silica dust control
unit, as shown in FIG. 4B;
[0032] FIG. 7A is a diagram showing an alternative embodiment of
the principles of the present invention in which a cover is
provided over portions of the representative frac sand
transportation and unloading system of FIG. 1 for containing silica
dust generated during movement of sand through the system;
[0033] FIG. 7B is a conceptual diagram providing a first detailed
view of a representative embodiment of the cover shown in FIG.
7A;
[0034] FIG. 7C is a conceptual diagram providing a second detailed
view of the representative embodiment of the cover shown in FIG.
7A;
[0035] FIG. 8A is a perspective view diagram of a representative
raised manifold system according to the principles of the present
invention, which is suitable for use in a frac sand silica dust
control system, such as that shown in FIG. 1;
[0036] FIG. 8B is an end elevational view diagram of the raised
manifold system of FIG. 8A;
[0037] FIG. 8C is a diagram providing a more detailed side
elevational view of a portion of the raised manifold system of FIG.
8A along with a representative number of attached dust collection
conduits;
[0038] FIG. 8D is a perspective view diagram of the raised manifold
system of FIG. 8A shown connected to an associated air movement
system and disposed within an enclosure suitable for containing
dust generated along the lateral conveyor and/or lifting conveyor
of FIG. 1;
[0039] FIG. 8E is a side elevational view diagram showing a
representative use of the raised manifold and enclosure system of
FIGS. 8A-8D in the system of FIG. 1, wherein the lateral conveyor
is enclosed and flexible conduits attached to the raised manifold
collect dust generated at points along the lateral conveyor and
from within the sand transportation and storage containers;
[0040] FIG. 8F is a perspective view diagram of an alternative
raised manifold and enclosure system according to the principles of
the present invention, which is suitable for use in a frac sand
silica dust control system such as that shown in FIG. 1;
[0041] FIG. 8G is a side elevational view diagram showing a
representative use of the raised manifold and enclosure system of
FIG. 8F in the system of FIG. 1, wherein the lateral conveyor is
enclosed and flexible conduits collect dust generated along the
lateral conveyor and from within the transportation and storage
containers;
[0042] FIG. 8H is a perspective view diagram of another alternative
raised manifold and enclosure system according to the principles of
the present invention, which is suitable for use in a frac sand
silica dust control system such as that shown in FIG. 1;
[0043] FIG. 81 is a top plan view diagram of an alternative sand
transportation and unloading system including a frac sand silica
dust control system using the raised manifold and enclosure system
of FIGS. 8A-8D;
[0044] FIG. 9A is a side elevational view diagram of another
alternative raised manifold and enclosure system according to the
inventive principles and suitable for containing dust generated in
and around a blender bin, blender tub, or both, in a dust control
system such as that shown in FIG. 1;
[0045] FIG. 9B is an end elevational view diagram of the raised
manifold and enclosure system shown in FIG. 9A, as connected to an
air system such as that shown in FIG. 1;
[0046] FIG. 9C is a perspective view diagram of the raised manifold
and enclosure system of FIGS. 9A-9B, shown connected to an air
system such as that shown in FIG. 1;
[0047] FIG. 9D is a perspective view diagram of a further
alternative raised manifold and enclosure system according to the
inventive principles, as connected to an air system such as that
shown in FIG. 1; and
[0048] FIG. 9E is a perspective view diagram of an additional
alternative raised manifold and enclosure system according to the
inventive principles, as connected to an air system such as that
shown in FIG. 1;
[0049] FIG. 9F is a top plan view diagram of an alternative sand
transportation and unloading system including a frac sand silica
dust control system using the raised manifold and enclosure system
of FIGS. 9A-9C.
DETAILED DESCRIPTION
[0050] The principles of the present invention and their advantages
are best understood by referring to the illustrated embodiment
depicted in FIGS. 1-9 of the drawings, in which like numbers
designate like parts.
[0051] FIG. 1 is a diagram of an exemplary frac sand
transportation, storage, and unloading system 100 including a frac
sand silica dust control system according to a preferred embodiment
of the principles of the present invention. System 100 is also
shown in the plan views of FIGS. 2 and 3, with FIG. 2 emphasizing
the air flow paths of the silica dust control system and FIG. 3
generally showing the locations of particular features of the
silica dust control system shown in further detail in FIGS.
4-6.
[0052] Generally, system 100 is assembled at a hydraulic fracturing
worksite and is used to offload frac sand transported to the
worksite from a frac sand supplier via trailers and offloaded into
a blender. The blender mixes the sand with the water and chemicals
to form the tracing fluid. Given the significantly large amounts of
frac sand that are typically required during typical hydraulic
fracturing operations, a substantial amount of potentially
hazardous silica dust is commonly generated during conventional
trailer offloading operations. The principles of the present
invention advantageously provide for the control of frac sand
produced silica dust, which consequently improves personnel safety,
helps reduce the need for respirators and other burdensome safety
equipment, and allows personnel to work longer and more efficiently
at the worksite.
[0053] In the illustrated embodiment of system 100 shown in FIGS.
1, 2, and 3, four (4) conventional sand storage trailers 101a-101d
are shown at a tracing worksite. While four (4) trailers 101 are
shown as an example, the actual number of sand storage trailers 101
utilized in any particular embodiment or configuration of system
100 may vary based on the needs and restrictions at the worksite.
The size and configuration of system 100 in any given worksite
application will depend on such factors as the amount of sand that
must be offloaded, the speed at which sand must be offloaded, and
the size and capabilities of the offloading conveyor system. In the
illustrated embodiment of system 100, each trailer 101 includes a
retractable trailer discharge conveyor (transfer belt) 102a-102d,
which receives sand from the compartments of the trailer internal
tank via a lateral transfer belt running underneath the trailer
tank (not shown). Trailers 101 are, for example, Sand King
3000/4000 frac sand trailers from Convey-All Industries, Inc.,
although there are a number of other commercially available sand
storage trailers known in the art. It should also be recognized
that the principles of the present invention are also applicable to
embodiments of system 100 in which sand is stored and discharged
from other types of fixed and transportable storage systems, such
as tanks, silos, compartmented vehicles, and so on.
[0054] Each trailer discharge conveyor 102a-102d discharges sand to
a conventional transportable conveyor system, for example, Unibelt
conveyor system from Convey-All Industries, Inc., which includes a
continuous transfer belt running through a lateral conveyor section
103 and a upwardly angled discharge conveyor section 105. During
typical offloading operations, one or more randomly selected
trailers 101 discharge sand to the lateral conveyor section 103 at
a given time.
[0055] Sand being discharged by each trailer discharge conveyor
102a-102d falls through slots 104 and onto lateral conveyor section
103. Lateral conveyor section 103 then carries the sand to upwardly
angled discharge conveyor section 105, which discharges the sand to
a bin of a blender truck 119 (FIGS. 3 and 5C), which mixes the sand
with water and chemicals in quantities needed for the formulation
of the particular tracing fluid being used.
[0056] The amount of sand being transferred at any one time in
system 100 can be substantial. For example, a Convey-All Unibelt
conveyor can nominally transfer and discharge 22,000 pounds per
minute of sand from trailers 101a-101d. The generation of a
corresponding substantial amount of fine silica dust is a natural
consequence of this transfer and discharge process.
[0057] According to the principles of the present invention, silica
dust generated during the offloading of trailers 101a-101d is
collected by suction at selected points around system 100 most
susceptible to the generation and discharge of silica dust. In the
preferred embodiment, silica dust is collected: (1) within the
compartments of the tanks of trailers 101a-101d; (2) at the base of
each trailer discharge conveyor 102a-102d, near the point at which
sand is received from the trailer lateral conveyor and the trailer
tanks; (3) at the point sand is discharged from trailer discharge
conveyors 102a-102d through slots 104 and onto lateral conveyor
section 103; (4) at multiple points along upwardly-angled discharge
conveyor section 105; and (5) near the point sand is discharged
from the spout of discharge conveyor 105 in to the bin of blender
119. It should be noted that in alternative embodiments, silica
dust may be collected at additional points, or even fewer points,
within system 100, as required.
[0058] The silica dust control function of system 100 is driven by
a silica dust control unit 106, which draws silica dust-bearing air
collected at points across the system though a pair of large
manifolds 107 and 108. In the illustrated embodiment of system 100,
silica dust control unit 106 also draws silica dust-bearing air
directly from trailer 101d through flexible hosing 109, although
this is not a strict requirement of the principles of the present
invention. Silica dust control unit 106, which may include a
baghouse and/or cyclone, separates the silica dust from the air and
discharges substantially silica dust-free air into the surrounding
environment. One exemplary silica dust control unit, suitable for
use as silica dust control unit 106 of system 100, is an ETI
Cyclone 20 DC system, available from Entech Industries, which
includes multiple twenty-inch (20'') inlets and produces a nominal
airflow of 20000 cubic feet per minute (cfm).
[0059] Silica dust control unit 106 establishes airflow in the
direction shown by arrows in FIG. 2. In the preferred embodiment,
two intake ports of silica dust control unit 106 are pneumatically
connected with manifolds 107 and 108, which run along corresponding
sides of lateral conveyor section 103, and one intake port of
silica dust control unit 106 is directly pneumatically connected to
trailer 101d through flexible hosing 109.
[0060] Silica dust generated in each of the compartments of
trailers 101a-101d is collected through a corresponding set of
fittings 110a-110f and hoses 111a-111e. In the illustrated
embodiment of system 100, the compartments of trailers 101a-101c
are pneumatically coupled to manifold 107 through flexible hosing
113a-113c. For trailer 101d, one fitting 110 is replaced with a
four-way fitting 112, which directly pneumatically couples the
compartments of trailer 101d with silica dust control unit 106.
[0061] Flexible hoses 114a-114c, which tap manifold 107, and the
flexible hose 114d, which taps manifold 108, collect silica dust at
the bases of each trailer discharge conveyor 102a-102d. Flexible
hoses 115a-115d, which tap manifold 108, collect silica dust at the
discharge points of trailer discharge conveyor 102a-102d into slots
104a-104c of lateral conveyor section 103. Flexible hoses
116a-116d, which tap manifold 108, collect silica dust moving up
upwardly angled discharge conveyor section 105. It should be noted
that the pneumatic paths between silica dust collection hoses 113,
114, 115, and 116 and silica dust control unit 106 may vary between
embodiments of system 100. In the preferred embodiment of system
100 shown in FIG. 1, the tapping point, as well as the manifold 107
or 108 being tapped, minimizes the lengths of manifolds 107 and 108
and silica dust collection hoses 113, 114, 115, and 116. Generally,
so long as sufficient suction is available at a given silica dust
collection point, the manifold 107 or 108 tapped, the point on the
manifold 107 or 108 tapped the corresponding flexible hose, or
both, may be varied.
[0062] A flexible hose 117, which taps manifold 107, captures
silica dust generated by the discharge of sand from upwardly angled
discharge conveyor 105 into the bin of blender 119. (While flexible
hose 117 taps manifold 107, in alternative embodiments flexible
hose 117 may tap manifold 108).
[0063] Manifolds 107 and 108 include a number of straight sections
120 and bent or curved sections 121 and are preferably constructed
as tubes or pipes of rigid metal, such as aluminum. Rigid metal
embodiments provide durability, particularly when manifolds 107 and
108 sit on or close to the ground and/or are exposed to contact by
personnel or to other structures within system 100. However, in
alternative embodiments, manifolds 107 and 108 may be constructed,
either in whole or in part, from sections of semi-rigid conduit or
flexible (corrugated) hose. For example, semi-rigid conduit or
flexible hose may be used in sections 121 of manifolds 107 and 108
that must be bent to provide a path around, over, or under, other
structures in system 100.
[0064] Preferably, manifolds 107 and 108 are each constructed in
multiple straight sections 120 and multiple bent or curved sections
121, which are clamped together using conventional clamps. This
preferred construction allows manifolds 107 and 108 to be
efficiently assembled and disassembled at the worksite, allows the
most direct paths to be taken to silica dust control unit 106, and
allows the overall system of conduits to be adapted to different
configurations of system 100 (e.g., different types and number of
trailers 101, different transportable conveyor systems, different
surface conditions).
[0065] Additionally, the diameters of the various sections of
manifolds 107 and 108 may increase or decrease, depending on the
airflow provided by the given silica dust control unit 106. The
diameters of manifolds 107 and 108 are determined by a number of
factors, including the intake diameters of silica dust control unit
106, the airflow produced by silica dust control unit 106, and the
amount of suction needed at the silica dust collection points.
Similarly, the diameters of silica dust collection hoses 113, 114,
115, and 116 will depend on factors such as the airflow available
from silica dust control unit 106, the diameters of manifolds 107
and 108, and the amount of suction required at a given hose inlet.
In one typical embodiment of system 100, manifolds 107 and 108 have
a nominal diameter of twenty inches (20'') and silica dust
collection hoses 113, 114, 115, and 116 are nominally within the
range of six to sixteen inches (6''-16'') in diameter. In other
words, the principals of the present invention advantageously allow
for variations in the components and configuration of system
100.
[0066] It should be recognized that the transportable conveyor
system, including lateral conveyor section 103 and discharge
conveyor section 105, is not always required. In this case, one or
more trailer discharge conveyors 102 discharge sand directly from
the corresponding trailers 101 into the bin of blender 119. In
embodiments of system 100 that do not utilize the transportable
conveyor system, only a corresponding number of flexible hoses 114
and 115 are required for collecting silica dust at the base and
outlet of each trailer discharge conveyor 102 discharging to
blender 119. (Along with the desired connections for removing dust
within the trailers 101 themselves.) Advantageously, only single
manifold 107 or 108 may be required in these embodiments.
[0067] FIG. 4A is a more detailed diagram showing the pneumatic
connections between manifolds 107 and 108 and silica dust control
unit 106. FIG. 4B shows the direct pneumatic connection between
trailer 101d and silica dust control unit 106 through flexible hose
109 in further detail.
[0068] FIGS. 4C-4E illustrate representative tapping points between
the heavier rigid sections 120 of manifolds 107 and 108 and
selected flexible hoses utilized in system 100. In particular, FIG.
4C shows a representative pneumatic connection between manifold 107
and hose 113c collecting silica dust from the tank compartments of
trailer 101c. FIG. 4D shows representative pneumatic connections
between manifold 108 and hose 114d, which collects silica dust
generated at the base of trailer discharge conveyor 102d, and hoses
115c and 115d, which collect silica dust generated at corresponding
outlets of trailer discharge conveyors 102c and 102d. FIG. 4E shows
representative pneumatic connections between manifold 108 and hoses
116a-116d collecting silica dust generated by discharge conveyor
section 105.
[0069] As well known in the art, numerous techniques are commonly
utilized for connecting flexible hose with a rigid conduit or pipe,
many of which are suitable for use in system 100. In the
illustrated embodiment shown in FIGS. 4C-4D, an aperture is tapped
through the wall of the given manifold 107 or 108 and the lower
periphery of a fitting (e.g., aluminum or steel pipe) 401 is
attached, for example, by welding or brazing. The lower section of
a coupling 402 is attached to the upper periphery of fitting 401,
for example by welding or brazing. The tubular upper section 403 of
coupling 402 is received with the periphery of the corresponding
hose, which is then clamped in place by one or more conventional
clamps 404. When necessary, an extension or elbow (not shown) may
be provided between upper section 403 of coupling 402 and the
corresponding hose. Similarly, a reduction coupling (see FIG. 5A,
designator 501) may be provided between upper section 403 and
coupling 402, as required to transition to the selected hose
diameter.
[0070] In the preferred embodiment shown in FIGS. 4C-4E, each
coupling 402 includes a slide gate, which provides for air flow
control between the given silica dust capture hose 113, 114, 115,
and 116 and the corresponding manifold 107 or 108. In addition to
allowing control of the amount of suction produced at the capture
hose inlet, these slide gates also allow any unused taps to
manifolds 107 and 108 to be completely shut off, particularly when
a hose is not connected to coupling 402.
[0071] FIG. 5A depicts in further detail representative silica dust
collection hose 114b collecting silica dust generated at the base
of trailer discharge conveyor 102b. Hose 114b pneumatically couples
with manifold 107 through a reduction coupling 501. The inlet end
of hose 114b, which includes an optional nozzle or shroud 502, is
disposed proximate the point where the lateral conveyor of trailer
101b discharges sand to the base of trailer discharge conveyor
102b. Silica dust generated during sand transfer is captured by the
suction created by silica dust control unit 106 at the discharge
end of hose 114b and carried through manifold 107 to silica dust
control unit 106 to be filtered from the air. Silica dust
collection hoses 114a, 114b, 114c, and 114d, which respectively
collect silica dust generated at the bases of trailer discharge
conveyors 102a, 102b, 102c and 102d, are similar in configuration
and operation.
[0072] FIG. 5B depicts in further detail representative silica dust
collection hose 115b collecting silica dust generated during the
discharge of sand from trailer discharge conveyor 102b into lateral
conveyor section 103. In the illustrated embodiment, trailer
discharge conveyor 102b discharges through a section of flexible
hose (conduit) 503 into the corresponding slot 104 of lateral
conveyor section 103. The inlet 504 of silica dust collection hose
115b is disposed proximate the outlet of flexible hose 503. The
suction produced by silica dust control unit 106 gathers silica
dust generated during the transfer of sand, which in turns moves to
silica dust control unit 106 for filtering through manifold 108.
The configuration and operation of silica dust collection hoses
115a, 115b, 115c, and 115d, which respectively collect silica dust
from the discharge points of trailer conveyors 102a, 102b, 102c,
and 102d into lateral conveyor section 103 are similar.
[0073] Silica dust collection hoses 116a-116d, and the suction
generated by silica dust control unit 106, collect silica dust
generated by the lifting and discharge of sand by discharge
conveyor section 105. As shown in FIG. 5C, silica dust collection
hoses 116a-116d extend from apertures through the body of discharge
conveyor section 105 at selected spaced-apart points. During
operation, silica dust generated as sand moves upwards towards the
outlet spout is removed through silica dust collection hoses
116a-116d and manifold 108 for filtering by silica dust control
unit 106.
[0074] FIG. 5C also one possible configuration for flexible 117
with respect to the spout of upwardly angled conveyor 105.
Generally, the intake end of flexible hose 117 is located near the
discharge point of the spout of conveyor 105 and creates an
updraft, which captures silica dust generated as sand falls into
the bin of blender 119. The actual attachment point of flexible
hose 117 to the spout of conveyor 105, as well as the proximity of
the intake end of hose 117 to the blender bin, may vary in actual
practice of system 100.
[0075] As discussed above, silica dust generated in the
compartments of the tanks of trailers 101a-101d is collected by a
set of fittings 110 and hoses 111. FIGS. 6A-6C depict this
subsystem in further detail, using trailer 101a as an example.
[0076] Each trailer 101 includes a set of inspection hatches 601
through the trailer roof. In the illustrated embodiment, trailers
101 include two rows of hatches 601 that run along opposing sides
of the trailer roof (In other embodiments of trailers 101, the
number and location of inspection hatches 601 may differ. For
example, some commercially available sand storage trailers utilize
a single row of inspection hatches that run along the centerline of
the trailer roof.)
[0077] In addition, FIG. 6A shows optional skirts 610, which run
along each side of the depicted trailer 101. Skirts 610, which are
preferably constructed from a durable flexible material, such as
heavy plastic or canvas, contain silica dust generated by the
movement of sand through the lateral conveyor that runs underneath
the trailer tank.
[0078] In the preferred embodiment of system 100, silica dust
collection is performed using the hatches 601 running along one
side of the trailer tank, although in alternative embodiments
silica dust collection could be performed using the hatches running
down both sides of the trailer tank. For a given compartment, the
regular hatch 602 is pulled back and replaced with corresponding
cover 603 attached an associated fitting 110 (FIGS. 6B-6D).
[0079] FIG. 6B shows in further detail an example of a T-shaped
(three-way) fitting 110e interfacing with corresponding hoses 111d
and 111e. FIG. 6C shows an example of a elbow (two-way) fitting
110a and the final section of hose 111a in the trailer silica dust
subsystem. The remaining connections between the given trailer 101
and fittings 110 and 111 are similar. The four-way fitting 112 used
to connect trailer 101d and silica dust control unit 106 through
hose 109 is shown in detail in FIG. 6D. In each case, fittings 110
include well-known transitions and clamps to connect to hoses 111.
Similar to the taps shown in FIGS. 4C-4E, each fitting, such as
T-shaped (three-way) fitting 110e, elbow fitting 110a, and four-way
fitting 112, includes a slide gate for controlling airflow between
the space within the given trailer 101 and manifold 107.
[0080] FIGS. 7A-7C illustrate an enhancement to system 100, which
includes a flexible cover system 700 for containing the silica dust
generated during the movement of sand through the system.
Preferably, flexible cover system 700 extends over the discharge
ends of trailer discharge conveyors 102a-102d, the length of
lateral conveyor section 103, and the length of upwardly angled
discharge conveyor section 105. (In alternative embodiments,
flexible cover system 700 may only cover portions of system 100, as
necessary to effectively control silica dust.)
[0081] In the preferred embodiment, flexible cover system 700 is
constructed as separate sections 701a-701c and 702, as shown in
FIGS. 7B and 7C. Sections 701a-701c cover corresponding portions of
lateral conveyor section 103 and section 702 covers upwardly angled
discharge conveyor section 105. Boots 703 are provided to allow
insertion of corresponding flexible capture hoses 115 and 116 into
the underlying silica dust containment spaces when cover system 700
is deployed. Boots 704 extend over the ends of trailer discharge
conveyors 102a-102d.
[0082] Section 702 also includes a lateral extension 705 for
covering the spout of upwardly angled discharge conveyor section
105. A boot 707 provides for the insertion of flexible hose 117
into extension 702 for fastening on or near the outlet of the
discharge spout of conveyor 105.
[0083] Flexible cover system 700 is preferably constructed of
canvas, heavy plastic, or other flexible material that is durable,
relatively easy to deploy and remove, and transportable.
Preferably, the surfaces of the selected material are impervious to
frac sand, as well as able to withstand the normal wear and tear
expected at a tracing worksite. When deployed, sections 701 and 702
are attached to each other with areas of Velcro 706 or similar
attachment system, which minimizes the escape of silica dust at the
seams between the sections.
[0084] FIGS. 8A and 8B are respectively perspective and end view
diagrams of a raised manifold system 800 suitable for use in frac
sand dust control systems, such as that described above in
conjunction with FIG. 1. Depending on the configuration of the dust
control system, raised manifold 800 may be used to replace either
or both of manifolds 107 and 108 of FIG. 1 or be used in addition
to manifolds 107 and 108.
[0085] As discussed further below, when in use in a dust collection
system such as system 100 of FIG. 1, raised manifold 800 is located
generally above lateral conveyor section 103, angled lifting
conveyor section 105, the bin and/or the tub of blender 119, or a
combination thereof. In the embodiment of FIG. 8A, raised manifold
800 is suspended from a support structure 801, which may also be
used to support a cover or enclosure for enclosing lateral conveyor
section 103, lifting conveyor section 105, and/or the bin and tub
of blender 119.
[0086] As shown in FIGS. 8A and 8B, fluid communication with the
interior passage of raised manifold 800 is through a set of rigid
cylindrical fittings 802 coupled to taps or apertures through the
manifold wall. In other words, fittings 802 provide a plurality of
ports into raised manifold 800 for capturing dust when negative air
pressure (i.e., suction) is applied to manifold 800, for example,
by air unit 106 in embodiments of system 100. In some instances,
fittings 802 are not required. For example, within a dust control
enclosure, such as those discussed further below, a port into the
interior of manifold 800 can be a simple aperture through the
manifold wall, which can be capped when not in use.
[0087] Two representative fittings are shown at 802a and 802b in
FIG. 8B for reference. The actual number of fittings 802 may vary
between embodiments, depending on such factors as the length of
raised manifold 800, the number of fittings 802 needed to support a
range of different dust control system configurations and dust
control operations, and the diameters of the flexible conduits
discussed below, among other things. In the illustrated embodiment,
each fitting 802 includes a sliding gate 803, two of which (802a
and 803b) are shown in FIG. 8B for reference. The amount of air
flowing through a given fitting 802 is set by the corresponding
sliding gate 803, which includes completely shutting-off air flow
through an unused or unnecessary fitting 802 (with or without a
rigid extension or attached flexible conduit.)
[0088] Preferably, raised manifold 800 and fittings 802 are
constructed from aluminum for lightness and durability, with
fittings 802 coupled to raised manifold 800 by welding or brazing.
However, in alternative embodiments, raised manifold 800, fittings
802, or both, may be fabricated from other materials, such as steel
or plastic, and fastened together using other fastening techniques.
For example, threads may be provided on fittings 802 for mating
with corresponding threads in the taps through the manifold
wall.
[0089] Moreover, while raised manifold 800 is shown as a rigid
conduit having a cylindrical shape, the principles of the present
invention may be embodied in raised manifolds of other shapes or
having different degrees of rigidity. For example, raised manifold
800 could be a flexible conduit or have a rectangular
cross-section. Generally, raised manifold 800 can be any conduit or
chamber having a size, shape, and rigidity suitable to provide
sufficient air flow through a sufficient number of branches (i.e.,
fittings or ports 802) as required to achieve the desired amount of
dust capture in a given dust control system having a given
configuration and a given air system rated cubic feet per minute
(cfm). (In the illustrated embodiment, rigid, cylindrical raised
manifold 800 is nominally 20 inches in diameter and fittings 802
are nominally 10 inches in diameter, based on 40000 cfm of air
flow, which could be provided by a single air system 106 or two air
systems 106 providing 20000 cubic feet cfm of air flow each.)
[0090] In the illustrated embodiment of FIGS. 8A and 8B, raised
manifold 800 is suspended from frame 801 by a series of
periodically spaced straps 804, two of which are shown for
reference at 804a and 804b. In alternative embodiment, other
techniques may be used to suspend raised manifold 800, such as
cables, cradles, direct bolting to support frame 801, tubing or
bars, among others. The particular suspension system configuration
may vary depending on such factors as the weight of raised manifold
800 and fittings 802, the number and size of fittings 802, the
length and diameter of raised manifold 800, and the ability to
quickly couple and uncouple raised manifold 800 and support frame
801.
[0091] Support frame 801 can be based on any one of a number of
different configurations and constructions. In the embodiment
illustrated in FIGS. 8A and 8B, support frame 801 includes a
central upper longitudinal reinforcing member 805, lower lateral
longitudinal reinforcing members 806a-806b, upper lateral
longitudinal reinforcing members 807a-807b, and U-shaped support
members 808, two of which are shown at 808a and 808b for reference.
Generally, each U-shaped support member 808 includes a pair of
opposing substantially straight vertical support members (legs) and
a curved upper section. While support frame 801 is shown as having
a generally inverted U-shape horizontal cross-section, other shapes
are possible, such as rectangular, triangular, or ovoid, for
example. When used in a dust control system such as system 100 of
FIG. 1, the width between the vertical support member of U-shaped
support members 808 is adapted to straddle the sides of lateral
conveyor section 103, the sides of lifting conveyor section 105,
the bin and/or tub of blender 119, the chutes from a vertical sand
mover, or a combination thereof.
[0092] Longitudinal reinforcing members 805, 806, and 807 and
U-shaped support members 808 are preferably fabricated and fastened
together to maximize durability and stability while still allowing
support frame 801 to be assembled and disassembled quickly at the
job site. For example, longitudinal reinforcing members 805, 806,
and 807 and U-shaped support members 808 may be fabricated as
aluminum or steel tubing and fastened together using pins or bolts.
Alternatively, longitudinal reinforcing members 805, 806, and 807
and U-shaped support members 808 could be solid aluminum or steel
bars or U-shaped beams. Support frame 801 could also be constructed
as sections in which some components are permanently fastened
together, for example by welding or brazing.
[0093] While raised manifold 800 is shown in FIGS. 8A and 8B as
being positioned along the longitudinal centerline of the upper
portion of support frame 801, generally referencing central upper
longitudinal reinforcing member 805, the lateral and vertical
position of raised manifold 800 may vary in alternative
embodiments. More specifically, raised manifold 800 may be
laterally and/or vertically displaced with respect to central upper
longitudinal reinforcing member 805. The actual location of raised
manifold 800 may be varied as needed, for example, to accommodate
different underlying structures, such as the discharge ends of
trailer conveyors 102 and angled lifting conveyor 105, or
variations in the length of the flexible conduits discussed
below.
[0094] In the illustrated embodiment, U-shaped frame members 808
are directly supported by the ground through bases 809, two of
which are shown at 809a and 809b for reference. In alternative
embodiments, U-shaped frame members 808 may be supported or
attached, either in whole or in part, by another structure within
the dust control system, such as lateral conveyor section 103,
blender 119, or angled lifting conveyor section 105. For example,
U-shaped frame members 808 may be attached or supported by the top
or fastened to a lateral surface of lateral conveyor section
103.
[0095] A given fitting 802 may be used unmodified (i.e., not
connected to a flexible conduit or rigid extension), connected to a
flexible conduit that extends towards the upper surface of lateral
conveyor section 103, to a point along angled lifting conveyor
section 105, or the bin and tub of blender 119, or may be extended
lengthwise to form a longer rigid conduit for drawing in air and
dust from a selected dust collection point, such as a point along
lateral conveyor section 103 or within the bin of blender 119. Not
all fittings 802 need be used, with those not being used closed by
the associated sliding gate 803 or capped.
[0096] FIG. 8C is a more detailed view of a portion of raised
manifold 800 and support frame 801. Representative fittings 802,
including fittings 802a and 802b of FIGS. 8A and 8B, are shown
connected to flexible conduits. Generally, local flexible conduits
810 are used to collect air and dust at selected points along
lateral conveyor section 103, along angled lifting conveyor 105, or
within the bin and/or tub of blender 119. Remote flexible conduits
811 are used to collect air and dust from within sand storage
containers, such as trailers 101 of FIG. 1.
[0097] FIG. 8C also shows an elbow conduit 812 for coupling raised
manifold 800 to a source of negative air pressure, such as air
system 106 of FIG. 1. Elbow conduit 812 is constructed, either in
whole or in part, by a rigid or semi-rigid material such as
aluminum, or a flexible material, such as rubber or polyurethane.
An additional fitting 802c and associated sliding gate 803c tap
into elbow conduit 812.
[0098] In FIG. 8D, raised manifold 800 is shown in combination with
an enclosure 814, which is configured to enclose lateral conveyor
section 103, angled lifting conveyor section 105, the bin and tub
of blender 119, or any combination of the three. Elbow conduit 812
couples with air unit 106 through a manifold system 813, which
includes sections of rigid and flexible conduit, although other
configurations may be used in alternative embodiments. For example,
air system 106 could be connected either to elbow conduit 812 or
directly to raised manifold 800 by a flexible conduit (i.e.,
eliminating elbow conduit 812, conduit system 813, or both). FIG.
8D also includes optional fitting/air flow control assemblies
818a-818b, which allow for additional local or remote flexible
conduits to be connected directly to conduit system 813.
[0099] The inlets of local flexible conduits 810 remain within
enclosure 814, while remote flexible conduits 811 run under bottom
edge 815 of enclosure 814 or through an aperture through the
sidewall of enclosure 814 near bottom edge 815. In alternative
embodiments, remote flexible conduits 811 could exit enclosure 814
at different points, including points higher up on the sidewalls of
enclosure 814 or through the enclosure 814 roof.
[0100] Enclosure 814 is not required for using raised manifold 800,
although use of enclosure 814 increases the efficiency of dust
capture through manifold 800 and flexible conduits 810, as well as
generally minimizes the escape of dust into the surrounding
environment. Moreover, when enclosure 814 is used, one or more
unmodified fittings 802 can be used for capturing dust within the
confined space. Furthermore, while enclosure 814 is shown as having
substantially clear sidewalls and an opaque roof, these are not
requirements for practicing the inventive principles. For example,
the sidewalls may be opaque and the roof may be substantially
clear, both the roof and the sidewalls may be opaque, or both the
roof and the sidewalls may be substantially clear.
[0101] In FIG. 8E, raised manifold 800 and enclosure 814 of FIG. 8D
are shown in use with an embodiment of frac sand transportation,
storage, and unloading system 100 of FIG. 1 including four (4)
transportation and storage containers 101a-101d coupled to four (4)
corresponding remote flexible conduits 811a-811d extending from the
bottom edge 815 of the opposing side of enclosure 814. Remote
conduits 811e-811i extending from the bottom edge 815 of the facing
side of enclosure 814 may be used for collecting dust at other
points within system 100, such as along lifting conveyor section
105 or from within additional sand storage and transportation
containers (see FIG. 8H).
[0102] In the example of FIG. 8E, at least four (4) local conduits
810a-810d extend downward within enclosure 814 from raised manifold
800 to collect dust generated from the discharge of sand from four
(4) container conveyors (stingers) 102a 102d to lateral conveyor
section 103. Preferably, in configurations where manifold 800 is
generally located above lateral conveyor section 103, such as those
shown in FIGS. 8E and 8G, manifold 800 is also located above the
discharge end of trailer discharge conveyors 102, as well.
[0103] FIG. 8F illustrates an alternative system configuration in
which raised manifold 800 is supported above support frame 801 and
outside of enclosure 814. In this configuration, local conduits 810
run generally down the sidewalls of enclosure 814, extend
underneath enclosure edge 815 or through apertures near enclosure
edge 815, and then extend further within enclosure 814 to the
corresponding dust collection points. Alternatively, local conduits
810 could enter the interior of enclosure 814 at different points,
such as through one or both of the enclosure sidewalls or through
the enclosure roof.
[0104] In the supported configuration of FIG. 8F, raised manifold
800 is supported by periodically spaced u-shaped cradles 819, two
of which are shown at 819a and 819b for reference. Cradles 819 are
fastened to central upper longitudinal reinforcing member 805 of
support frame 801, for example, by bolts or pins. Alternatively,
raised manifold 800 could be directly fastened to upper
longitudinal reinforcing member 805 or fastened to support
structure 801 using another technique. Furthermore, while raised
manifold 800 is shown positioned along the centerline generally
defined by central upper longitudinal reinforcing member 805, it
could be laterally and/or vertically displaced from the centerline
in alternative embodiments.
[0105] In FIG. 8G, the supported configuration of raised manifold
800 and enclosure 814 are shown in use with an embodiment frac sand
transportation, storage, and unloading system 100 of FIG. 1
including four (4) transportation and storage containers 101a-101d
coupled to four (4) corresponding remote flexible conduits 811a
811d coupled to corresponding fittings 802 on the opposing side of
raised manifold 800. Remote conduits 811e-811j extending from
fittings 802 on the facing side of enclosure 814 may be used for
collecting dust at other points within system 100, such as along
lifting conveyor section 105 or from within additional sand storage
and transportation containers.
[0106] In the example of FIG. 8G, at least four (4) local conduits
810a-810d extend downward outside of the sidewall of enclosure 814,
extend underneath enclosure edge 815 or through apertures near
enclosure edge 815, and then extend upward within cover 814 to
collect dust generated from the discharge of sand from four (4)
container conveyors (stingers) 102a-102d to lateral conveyor
section 103.
[0107] An alternative configuration is shown in FIG. 8H, where
manifold 800 remains outside of enclosure 814 and is supported by
support structure 801, but is now located lower down the side of
the support structure 801. While manifold 800 is shown generally at
the point where U-shaped support members 808 transition from a
curve to vertical support members, manifold 800 can be placed at
any point between the very top of support structure 801 (FIGS. 8F
and 8G) and the ground. In addition, manifold 800 can be positioned
on either side of support structure 801, as need for a particular
worksite or dust control system configuration.
[0108] In the embodiment of FIG. 8H, manifold 800 is preferably
secured directly to support frame 801 by bolts, pins, or a similar
fastening technique. Remote flexible conduits 811 then extend over
the upper curved portion of support structure 801 and enclosure
814. In some embodiments, flexible conduits 810 could extend
through the top portion (roof) of enclosure 814 to capture dust
within the enclosure interior. Local flexible conduit 810e is an
example of a flexible conduit extending through the top portion of
enclosure 814.
[0109] FIG. 81 illustrates an example in which remote conduits 811
extend from both sides of raised manifold 800. In this example,
raised manifold 800 is shown in the configuration of FIGS. 8A-8E,
although the same principles apply to the configuration shown in
FIGS. 8F-8G. Here, three (3) remote conduits 811a-811c service
three (3) sand transportation and storage containers 101a-101c and
two (2) remote conduits 811d-811e service two (2) portable silos or
vertical sand movers 816a-816b. (The number of sand sources, such
as transportation and storage containers 101 and portable
silos/vertical sand movers 816 may vary in actual practice.) Within
enclosure 814, at least one local flexible conduit 810 or extended
fitting 802 collects dust generated around each of the sand
discharge points from trailer conveyors 102a-102b and the sand
discharge points from portable silo chutes 817a-817b.
[0110] The principles of the present invention are also embodied in
a raised manifold and enclosure system more specifically adapted
for containing and collecting dust generated in and around the bin
and tub of blender 119. One such system is shown in FIG. 9A, which
includes a raised manifold 900 suspended below a support structure
901 by a set of straps or cables, two of which are shown at 910a
and 910b for reference. Preferably, the construction of support
structure 901 and straps/cables 910 are similar to those of support
structure 801 and straps/cables 804 discussed above, although that
is not a strict requirement of practicing the inventive principles.
Support structure 901 also supports an enclosure 907, which is
preferably similar in construction to enclosure 814 discussed
above.
[0111] In the embodiment shown in FIG. 9A, raised manifold 900
includes a set of fittings, such as fittings 902a and 902b, which
are in fluid communication with the interior passage through raised
manifold 900. Similar to fittings 802 discussed above, fittings 902
provide a plurality of ports into raised manifold 900 for capturing
dust when negative air pressure (i.e., suction) is applied to
manifold 900, for example, by air unit 106 in embodiments of system
100. Each fitting 902 is associated with an air flow control
device, which could be a gate, butterfly valve, ball valve, or
similar device, controls air flow control through the corresponding
fitting 902. (Air flow control preferably extends from a complete
airflow shut-off to a maximum allowable flow through the given
fitting 902 under the given system operating conditions.) In the
illustrated embodiment, sliding gates 903a and 903b are shown as an
example. While four (4) fittings 902 are shown in the exemplary
embodiment of FIG. 9A, the number of fittings 902 may vary in
actual applications, depending on the dust-capture
requirements.
[0112] Fittings 902 can be used unmodified (e.g., without a
flexible conduit or rigid extension), with a rigid extension, or in
conjunction with a flexible conduit or rigid extension. Unmodified
or extended fittings 902 are particularly suitable for capturing
dust contained within enclosure 907. Fittings 902 connected to
flexible conduits are suitable for capturing dust at one or more
points within enclosure 907, as well as one or more points outside
of enclosure 907. Not all fittings 902 need be used and unused
fittings 902 can be shut-off using the corresponding sliding gates
903.
[0113] The construction of raised manifold 900 is preferably
similar to that of raised manifold 800 discussed above. As with
raised manifold 800, characteristics such as shape, fabrication
material, degree of rigidity, and so on, may vary from embodiment
to embodiment of the present inventive principles.
[0114] As shown in FIG. 9A, all four (4) exemplary fittings 902 are
coupled to a corresponding set of four (4) flexible conduits. Two
(2) fittings 902 are connected to local flexible conduits 904a and
904b, which extend downward within cover 907 for capturing dust in
the areas around the bin and tub of blender 119 (see FIG. 9E). In
addition, two other fittings 902 are coupled to remove flexible
conduits 905a-905b, which extend under the bottom edge 909 or
through an aperture close to bottom edge 909 of enclosure 900.
Remote flexible conduits 905 may be used to capture dust at other
points around a frac sand storage and movement system, for example,
dust within a trailer 101, dust generated along lateral conveyor
system 103, or dust generated along angled lifting conveyor 105 of
an embodiment of system 100 of FIG. 1. In alternative embodiments,
remote flexible conduits 905 could exit enclosure 907 at different
points, including points higher up on the sidewalls of enclosure
907 or through the enclosure 907 roof.
[0115] A elbow-shaped conduit 906 couples raised manifold 900 to an
air system 106, which is similar to those discussed above. In one
particular configuration shown in FIGS. 9B and 9C, rigid
elbow-shaped conduit 906 communicates with an air system 106
through a manifold system 908 formed of both rigid and flexible
sections of conduits, although other configurations may be used in
alternative embodiments. For example, air system 106 could be
connected either to elbow-shaped conduit 906 or directly to raised
manifold 900 through a flexible conduit or conduit.
[0116] FIG. 9D shows an alternative configuration where raised
manifold 900 is supported above the roof of enclosure 907 by frame
901 and u-shaped cradles 920a 920b. In this configuration, local
conduits 904 run generally down the sidewalls of enclosure 907,
extend underneath enclosure edge 909 or through apertures near
enclosure edge 909, and then extend further within enclosure 907 to
the corresponding dust collection points. Alternatively, local
conduits 904 could enter the interior of enclosure 907 through one
or both of the enclosure sidewalls or through the roof. In
addition, while cradles 920 are shown as u-shaped in the
illustrated embodiment, different cradle shapes may be used in
alternate embodiments.
[0117] A further alternative configuration is shown in FIG. 9E,
where manifold 900 remains outside of enclosure 907 and is
supported by support structure 901, but is now located lower down
the side of the support structure 901. While manifold 900 is shown
generally at the point where support structure 901 transitions from
a curve to vertical support members, manifold 900 can be placed at
any point between the very top of support structure 901 (FIG. 9D)
and the ground. In addition, manifold 900 can be positioned on
either side of support structure 901, as need for a particular
worksite or dust control system configuration. FIG. 9D also shows
optional fittings/air flow control assemblies 913a-913b, which
allow additional local or remote flexible conduits to be connected
directly with manifold system 908.
[0118] In the embodiment of FIG. 9D, manifold 900 is shown
supported by a set of cradles 920a-920b extending outwardly from
support frame 901, although manifold 900 could also be secured
directly to support frame 901 by bolts, pins, or a similar
fastening technique. Remote flexible conduits, such as remote
flexible conduit 905b, can then extend over the upper curved
portion of support structure 901 and enclosure 907. In some
embodiments, one or more local flexible conduits 904, such as local
flexible conduit 904b, could extend through the top portion of
enclosure 907 to capture dust within the enclosure interior.
[0119] FIG. 9F illustrates an alternative frac sand transportation,
storage, and unloading system 911 including a frac sand silica dust
control system suitable for use with either of the configurations
of raised manifold 900 shown in FIGS. 9A and 9D. Preferably,
enclosure 907 encloses the bin, the tub, or both the bin and tub of
blender 119. In FIG. 9F, enclosure 907 encloses both the blender
bin and the blender tub, as generally shown in broken lines. At
least one fitting 902, which may be unmodified, extended, or
connected to a local flexible conduit 904, as shown in FIG. 9F,
collects dust contained by enclosure 907.
[0120] In the system of FIG. 9F, the container conveyors (stingers)
102a-102c associated with trailers 101a-101b extend through
apertures in the sidewalls of enclosure 907 and discharge sand
directly into the bin of blender 119. Preferably, manifold 900 is
located above the discharge end of container conveyors 102a-102c
(or in embodiment using one or more silo chutes, above the
discharge ends of the silo chutes). In addition, FIG. 9E provides
an example where two (2) manifolds and two (2) air systems are used
to collect dust at various points around the system.
[0121] Specifically, air system 106a and manifold 912 are used to
collect dust within the compartments of trailers 101a-101b. Air
system 106b and raised manifold 900 capture dust within enclosure
907, as well as provide a remote flexible conduit 905 for
collecting dust within some of the compartments of trailer 101a.
Raised manifold 900 and manifold 912 may also be coupled together
to create a unified conduit system serviced by either or both of
air systems 106a-106b.
[0122] FIG. 9F only shows one possible use of raised manifold 900.
Raised manifold 900 can be used alone to collect dust around the
bin and tub of a tracing blender, provide negative air pressure to
one or more local flexible conduits 905 for collecting dust along a
lateral conveyor, lifting conveyor, a container conveyor, or silo
chute, and/or provide negative air pressure through one or more
remote flexible conduits 905 for collecting dust within a sand
trailer or portable sand silo. Raised manifold 900 may also be use
in conjunction with raised manifold 800 and enclosure 814.
Advantageously, when raised manifolds 800 are 900 are used in
combination, a wide range of options are available for collecting
dust around a given frac sand transportation, storage, and handling
system.
[0123] In sum, the principles of the present invention provide for
the efficient capture and removal of silica dust generated during
the offloading of frac sand at a worksite. Silica dust removal is
performed near, but not limited to, substantial sources of
hazardous silica dust, including at trailer to trailer conveyor
sand transfer point, each point of transfer from the trailer
discharge conveyors and the lateral site conveyor, and points along
the lifting/discharge conveyor. The embodiments of the inventive
principles are scalable, and can be applied to any discharging
system serving single or multiple frac sand storage trailers and
can be implemented with various commercially available
cyclone/baghouse silica dust removal systems. Moreover, the
configuration and construction of these embodiments are also
variable, allowing silica dust control to be effectively
implemented under widely varying worksite conditions.
[0124] Although the invention has been described with reference to
specific embodiments, these descriptions are not meant to be
construed in a limiting sense. Various modifications of the
disclosed embodiments, as well as alternative embodiments of the
invention, will become apparent to persons skilled in the art upon
reference to the description of the invention. It should be
appreciated by those skilled in the art that the conception and the
specific embodiment disclosed might be readily utilized as a basis
for modifying or designing other structures for carrying out the
same purposes of the present invention. It should also be realized
by those skilled in the art that such equivalent constructions do
not depart from the spirit and scope of the invention as set forth
in the appended claims.
[0125] It is therefore contemplated that the claims will cover any
such modifications or embodiments that fall within the true scope
of the invention.
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