U.S. patent application number 10/961620 was filed with the patent office on 2005-05-19 for submerged combustion water heater.
Invention is credited to Engdahl, Gerald E..
Application Number | 20050103323 10/961620 |
Document ID | / |
Family ID | 34577650 |
Filed Date | 2005-05-19 |
United States Patent
Application |
20050103323 |
Kind Code |
A1 |
Engdahl, Gerald E. |
May 19, 2005 |
Submerged combustion water heater
Abstract
This invention discloses a submerged combustion apparatus and
method for heating large quantities of water and other fluids in
many applications. Water to be heated exits an orifice opening and
flows across a perforated plate where the water is heated by
products of combustion passing through apertures in the perforated
plate. The low submergence, low backpressure heat and mass transfer
arrangement provides an effective and efficient system for heating
water and other fluids and concentrating water solutions.
Inventors: |
Engdahl, Gerald E.;
(Wheaton, IL) |
Correspondence
Address: |
GERALD E. ENGDAHL
1425 OXFORD LANE
WHEATON
IL
60187
US
|
Family ID: |
34577650 |
Appl. No.: |
10/961620 |
Filed: |
October 8, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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60516845 |
Nov 3, 2003 |
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60511827 |
Oct 16, 2003 |
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Current U.S.
Class: |
126/355.1 |
Current CPC
Class: |
F23C 3/004 20130101;
F22B 1/1853 20130101; F22B 1/265 20130101 |
Class at
Publication: |
126/355.1 |
International
Class: |
F24H 001/10 |
Claims
What is claimed:
1. A submerged combustion water heating apparatus comprising: a
combustion chamber; a burner assembly firing into the combustion
chamber and producing products of combustion; at least one set of
perforated plates; wherein the products of combustion flow
generally through apertures in the perforated plate; a submerged
combustion water inlet plenum, a water inlet means and a submerged
combustion water outlet plenum; wherein water is directed through
the submerged combustion inlet plenum, through the water inlet
means to flow generally across at least one set of perforated
plates and be heated by the products of combustion and collected in
the submerged combustion water outlet plenum.
2. The apparatus of claim 1, further comprising one or more from
the group consisting of: (a) where the products of combustion
include vaporized water; (b) where an annular plate system is
located above a perforated plate; (c) where an annular plate system
provides space for heat and mass transfer surface area contact
between water and the products of combustion; (d) where a portion
of the water flows through apertures in the perforated plate; (e)
where the submerged combustion water outlet plenum includes at
least one liquid seal to contain the products of combustion; (f)
where the burner assembly operates with a backpressure of less than
one pound per square inch; (g) where the water inlet means includes
a down corner and orifice opening; (h) where water and other fluids
are heated and vaporized or heated or vaporized or concentrated;
(i) where products of combustion are recirculated to the burner
assembly; (j) where flue products of combustion are heated and
recirculated to the burner assembly; (k) where flue products of
combustion from an external source are routed to the burner
assembly; (l) where the fluids to be heated or vaporized include
particulate matter; (m) where the products of combustion are
contacted with a water spray.
3. A submerged combustion method of heating a fluid including the
steps of: providing a source of products of combustion and a fluid
inlet means; providing at least one set of perforated plates;
directing fluid to flow through fluid inlet means and generally
across at least one set of perforated plates; passing products of
combustion through apertures in the perforated plate; contacting
the fluid and the products of combustion; heating the fluid using
products of combustion; and collecting the heated fluid.
4. The apparatus of claim 3, further comprising one or more from
the group consisting of: (a) where the products of combustion
include vaporized water; (b) where an annular plate system is
located above a perforated plate; (c) where an annular plate system
provides space for heat and mass transfer surface area contact
between fluid and the products of combustion; (d) where a portion
of the fluid flows through apertures in the perforated plate; (e)
where the fluid inlet means includes a submerged combustion fluid
inlet plenum, a down corner and orifice opening; (f) where water
and other fluids are heated and vaporized or heated or vaporized or
concentrated; (g) where products of combustion are recirculated to
the source of products of combustion; (h) where flue products of
combustion are heated and recirculated to the source of products of
combustion; (i) where flue products of combustion from an external
source are routed to the source of products of combustion; (j)
where the fluids to be heated or vaporized include particulate
matter; (k) where the products of combustion are contacted with a
fluid spray.
5. A submerged combustion heat source vaporizer comprising: a
combustion chamber; a burner assembly firing into the combustion
chamber and producing products of combustion; at least one set of
perforated plates; wherein products of combustion flow generally
through apertures in at least one set of perforated plates; a
submerged combustion heat source water inlet plenum, a submerged
combustion water inlet means, and a submerged combustion heated
water plenum; wherein water is directed through the submerged
combustion heat source water inlet plenum and through the submerged
combustion water inlet means to flow generally across the
perforated plate and be heated by the products of combustion and be
collected in the submerged combustion heated water plenum; an
annular space; wherein the submerged combustion heated water plenum
communicates with the annular space; at least one inlet manifold
and at least one outlet manifold; rows of spiral tube heat transfer
circuits for containing and vaporizing fluids being positioned
generally within the annular space and communicating with at least
one inlet manifold; a water outlet plenum communicating with the
annular space; wherein the water outlet plenum communicates with
the submerged combustion heat source water inlet plenum; and at
least one pump circulating water from the water outlet plenum to
the submerged combustion heat source water inlet plenum.
6. The LNG vaporizer of claim 5, further comprising one or more
from the group consisting of: (a) where a spiral tube heat transfer
circuit and annular space is arranged to provide substantially
cross flow heat transfer; (b) where the vaporizer is provided with
an interstage manifold communicating with the spiral tube circuits;
(c) where the interstage manifold provides means for liquid
separation; (d) where a spiral tube heat transfer circuit is
generally supported on support rods, tubes or bars; (e) where the
products of combustion include vaporized water; (f) where an
annular plate system is located above a perforated plate; (g) where
an annular plate system provides space for heat and mass transfer
surface area contact between water and the products of combustion;
(h) where a portion of the water flows through apertures in the
perforated plate; (i) where various fluids including LNG are heated
and vaporized or vaporized or heated; (j) where several heat
sources provide the heat or where the water contains particulate
matter; (k) where products of combustion are recirculated to the
burner assembly; (l) where flue products of combustion are heated
and recirculated to the burner assembly; (m) where flue products of
combustion from an external source are routed to the burner
assembly; (n) where the submerged combustion heated water outlet
plenum includes at least one liquid seal to contain the products of
combustion; (o) where other types of heat transfer circuits are
included; (p) where the burner assembly operates with a
backpressure of less than one pound per square inch; (q) where
water includes fluids and water solutions; (r) where rows of spiral
tube heat transfer circuits are generally supported on support rods
and the support rods for a row are positioned to provide vertical
clearance between a row of spiral tube heat transfer circuits and
the support rods supporting the row of spiral tube heat transfer
circuits located above and allowing independent movement of each
row of spiral tube heat transfer circuits; (s) where the tube pitch
of selected tubes within a spiral tube heat transfer circuit is
adjusted to accommodate tube icing or adjusted to accommodate
heating medium flow or both.
Description
RELATED APPLICATIONS
[0001] This application claims domestic priority from provisional
application Ser. No. 60/516,845, SPIRAL TUBE LNG VAPORIZER filed
Nov. 3, 2003 and provisional application Ser. No. 60/511,827,
SUBMERGED COMBUSTION WATER HEATER filed Oct. 16, 2003, the entire
disclosures of which are incorporated herein by reference. Engdahl
U.S. Patent application, SPIRAL TUBE LNG VAPORIZER filed on Oct. 8,
2004 and Engdahl U.S. Patent application SUBMERGED COMBUSTION LNG
VAPORIZER filed on Oct. 8, 2004 is incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to heating water.
More specifically, the present invention relates to a high
efficiency, high capacity, submerged combustion apparatus and
method for heating water and other liquids.
BACKGROUND OF THE INVENTION
[0003] Submerged combustion is a high efficiency system for heating
water and other liquids. The liquid is heated by direct contact
heat and mass transfer with hot products of combustion. The liquid
is generally water, but other solutions may be heated. Various
systems are employed to provide the direct contact transfer between
the products of combustion and the liquid to be heated. The thermal
efficiency of a submerged combustion system heating liquids can be
higher than 90%. A submerged combustion water heater with a stack
gas temperature of 70 degrees F. has a thermal efficiency of about
100%.
[0004] The submerged combustion system is used for heating large
quantities of liquids at high efficiencies in many industrial and
commercial applications. In addition to heating liquids, submerged
combustion is utilized for concentrating water solutions by
evaporating water from the solution.
[0005] The conventional heater is equipped with submerged
combustion burners firing into a liquid bath. The products of
combustion are discharged into the bath. The discharge location is
generally at a liquid submergence depth greater than two feet. The
burner system includes a large high horsepower blower for providing
combustion air. The submerged combustion burner provides heat,
circulation, and turbulence for heat transfer.
[0006] There are many patents describing submerged combustion water
heaters. The patents describe submerged pressurized products of
combustion being bubbled through various combinations of holes and
weirs to contact and heat water. The products of combustion are at
a pressure sufficiently high to overcome the submergence depth.
Deeper submergence depths require larger and higher horsepower
combustion air blowers. In an application where the burner assembly
discharges into water with an equivalent depth of 48 inches, the
blower discharge pressure would need to be 48 inches water column
plus the additional pressure drop of the system. Other patents
disclose various water spray arrangements contacting the products
of combustion to heat water. These patents do not teach or suggest
the products of combustion and water flow arrangement of this
disclosure nor do they present the arrangement used to contact the
products of combustion with the water flow to heat water as taught
in this specification.
[0007] Objectives
[0008] Several objectives of this patent follow:
[0009] To provide a high thermal efficiency system for heating
water and other fluids.
[0010] To provide a submerged combustion system with operates with
low combustion gas back pressure.
[0011] To provide a high capacity water heating system.
[0012] To provide a single burner water heating system.
[0013] To provide an arrangement with less potential for apparatus
vibration.
[0014] To provide a burner/blower system with low installed
horsepower.
[0015] To provide a submerged combustion system heating water with
low water pressure drop across the apparatus.
[0016] To provide a high capacity submerged combustion system for
heating water circulating in a loop and heating once through water
flow applications.
[0017] To provide the heat source for a complete system for
vaporizing LNG.
[0018] To provide a submerged combustion system meeting air quality
regulations.
[0019] To provide a submerged combustion heater for many commercial
and industrial applications including vaporizing water and other
fluids and concentrating solutions.
[0020] To provide a system which can be quickly and easily started
and shutdown.
SUMMARY OF THE INVENTION
[0021] In accordance with one aspect of the invention, a submerged
combustion water heating apparatus comprising a combustion chamber,
a burner assembly firing into the combustion chamber and producing
products of combustion, at least one set of perforated plates,
wherein the products of combustion flow generally through apertures
in the perforated plate, a submerged combustion water inlet plenum,
a water inlet means and a submerged combustion water outlet plenum,
wherein water is directed through the submerged combustion inlet
plenum, through the water inlet means to flow generally across at
least one set of perforated plates and be heated by the products of
combustion and collected in the submerged combustion water outlet
plenum.
[0022] In accordance with another aspect of the invention, a
submerged combustion method of heating a fluid including the steps
of providing a source of products of combustion and a fluid inlet
means, providing at least one set of perforated plates, directing
fluid to flow through fluid inlet means and generally across at
least one set of perforated plates, passing products of combustion
through apertures in the perforated plate, contacting the fluid and
the products of combustion, heating the fluid using products of
combustion and collecting the heated fluid.
[0023] In accordance with yet another aspect of the invention, a
submerged combustion heat source vaporizer comprising a combustion
chamber, a burner assembly firing into the combustion chamber and
producing products of combustion, at least one set of perforated
plates, wherein products of combustion flow generally through
apertures in at least one set of perforated plates, a submerged
combustion heat source water inlet plenum, a submerged combustion
water inlet means, and a submerged combustion heated water plenum,
wherein water is directed through the submerged combustion heat
source water inlet plenum and through the submerged combustion
water inlet means to flow generally across the perforated plate and
be heated by the products of combustion and be collected in the
submerged combustion heated water plenum, an annular space, wherein
the submerged combustion heated water plenum communicates with the
annular space, at least one inlet manifold and at least one outlet
manifold, rows of spiral tube heat transfer circuits for containing
and vaporizing fluids being positioned generally within the annular
space and communicating with at least one inlet manifold, a water
outlet plenum communicating with the annular space, wherein the
water outlet plenum communicates with the submerged combustion heat
source water inlet plenum, and at least one pump circulating water
from the water outlet plenum to the submerged combustion heat
source water inlet plenum.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is an elevation cross section of a cylindrical
submerged combustion heater.
[0025] FIG. 2 is an elevation cross section of a cylindrical
submerged combustion heater with an outlet water liquid seal
arrangement.
[0026] FIG. 3 is an elevation cross section of a cylindrical
submerged combustion water heater of this invention utilized as a
heat source for a submerged combustion LNG vaporizer.
[0027] FIG. 4 is an elevation cross section detail showing an
annular plate.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The present invention discloses a submerged combustion water
heating system which differs from conventional submerged combustion
heaters. A unique products of combustion and water flow arrangement
provides the heat and mass transfer contact between the water and
the products of combustion. The submerged combustion system using
this unique arrangement has high efficiency and many
advantages.
[0029] FIG. 1 and FIG. 2 show two arrangements of the submerged
combustion heating system. The water heating portion of both
heaters is similar. The submerged combustion arrangement in FIG. 1
is used for heating water circulating in a loop and for heating a
large quantity of water flowing through the submerged combustion
apparatus. In the circulating loop application the quantity of
water returning to the submerged combustion apparatus is
essentially the same as that leaving. Heated water leaves the
submerged combustion system and circulates through a heat exchanger
or similar system where heat is extracted from the water. A pump is
generally used to circulate the water. The cooler water returns to
the submerged combustion system to be reheated. The water pH of the
submerged combustion system operating in a closed loop can fall.
The addition of chemicals to maintain the proper water quality may
be required. The combustion reaction produces water. At cooler
submerged combustion operating temperatures the produced water is
retained in the submerged combustion apparatus. The quantity of
water in the circulating loop will increase at a low rate. The
submerged combustion system operating at warmer temperatures will
have a net decrease in water quantity in the submerged combustion
apparatus as a result of water leaving the submerged combustion
apparatus via the flue stack. The addition or loss of water in the
circulating loop results in level changes in the apparatus water
level. Controls are provided to discharge or add water to maintain
the operating water level. Heating water flowing through the
submerged combustion FIG. 1 arrangement not in the circulating loop
configuration requires control means to maintain the operating
water level in the apparatus.
[0030] The submerged combustion arrangement in FIG. 2 is used in
applications such as snow melting where the heated water is open to
the atmosphere. The FIG. 2 submerged combustion arrangement can be
used for concentrating water solutions by evaporation. The FIG. 2
submerged combustion arrangement can also be used for the same
types of applications as those of the FIG. 1 arrangement. In
addition to heating water, both arrangements can be used for
heating sea water, water solutions and other fluids. Both
arrangements can be used in applications where the heated water
flows to a heated water user such as a vaporizer or heat
exchanger.
[0031] Referring now to FIG. 1, the submerged combustion
cylindrical shaped water heating apparatus 10 is shown in FIG. 1.
The apparatus 10 includes the burner assembly 11 firing into the
combustion chamber 12 producing products of combustion gases. The
burner assembly 11 includes the combustion air blower and motor.
The combustion chamber 12 is of sufficient diameter and length to
obtain the required combustion efficiency and required emissions in
combination with the burner assembly. An outer cooling jacket 13
provides an annular space surrounding the combustion chamber. Water
is directed to the cooling jacket annular space for cooling the
combustion chamber wall by pump 14. In some applications a portion
of the inlet water can be directed to the annular space for
cooling, thereby eliminating pump 14. A portion of the combustion
chamber cooling flow can evaporate and produce steam as it exits
the annular space. Means can be provided to increase the portion
and quantity of combustion chamber cooling flow being evaporated.
The resulting vaporized water will combine with the products of
combustion. The composition of the term "products of combustion" as
provided in this disclosure will include water vapor produced
during the combustion process and can include additional water
vapor from other sources. The products of combustion exit the
combustion chamber 12 and flow through apertures in perforated
plate 15 in a generally ascending manner contacting water flowing
across perforated plate 15. The perforated plate 15 is installed
with a slope as shown or can be installed horizontally, or at other
positions. The length of the perforated plate is sized to provide
sufficient contact area between the flowing water and the
combustion products and sized for other considerations. The
perforated plate can also be plate or tray arrangements with
apertures. Another set of perforated plates can be included stacked
above the other to provide additional contact area. The stacked
plates are arranged such that the products of combustion flow
through each plate. A plate arrangement as shown in FIG. 4 and
described later provides additional heat and mass transfer contact
area between the water and the products of combustion. The
combustion products exit the perforated plate 15 in FIG. 1 and are
collected in the lower flue plenum 16 and pass through several flue
vents 17 to the upper flue plenum 18. An optional water spray
system 19 can be installed in upper flue plenum 18 to further cool
the products of combustion and increase the efficiency. Some
liquids subjected to submerged combustion can produce foaming. The
spray system 19 can also be used to reduce foaming, if foam is
present. The flue plenums 16 and 18 can be sized to help reduce the
quantity of foam and water entering the flue stack. The flue stack
20 connects to the upper flue plenum 18. The flue stack 20
discharges the flue products to atmosphere. Alternately, the flue
stack 20 can be connected directly to the flue vent 17. The upper
flue plenum 18 would be eliminated in this alternate arrangement.
Several flue stacks would be required. A flue stack would be
required for each flue vent. The optional water spray system 19
would be located in the lower flue plenum 16 in this alternate
arrangement.
[0032] The water side of the submerged combustion system is
designed in a unique way to accommodate large water flows. These
large water flows are heated with efficient contacting means. The
required pressure of the products of combustion is low. The inlet
water to be heated in FIG. 1 enters the inlet plenum 21. The inlet
plenum 21 is vented to the atmosphere via vent 22. The inlet water
is distributed to the inlet water down corner 23 and flows through
orifice opening 24. Orifice opening 24 can be adjustable. Orifice
opening 24 is the opening between down corner plate 25 and
perforated plate 15. Additional orifice openings can be provided to
accompany additional sets of stacked perforated plates. The water
exiting orifice opening 24 flows as a high velocity stream
generally across perforated plate 15 contacting products of
combustion flowing through apertures in perforated plate 15
providing heat and mass transfer between the streams. A small
portion of the water may flow through holes in perforated plate 15.
The water flowing generally across perforated plate 15 discharges
into outlet water plenum 26. Adjustable baffle plate 27 prevents
products of combustion from bypassing perforated plate 15. Baffle
plate 27 provides a liquid seal to contain the products of
combustion. Means are provided to direct a stream of water toward
or along baffle plate 27 for cooling of the plate (not shown).
Baffle plate 27 can be positioned to provide a depth adjustment for
water flowing over perforated plate 15. Control means are provided
to maintain plenum 26 water level within operating limits (not
shown). A baffle arrangement can be included in plenum 26 to help
inhibit wave action. The heated water exits outlet water plenum 26.
The patent configuration provides ample heat and mass transfer area
between the products of combustion and water. The contact area
includes the heated water plenum 26 surface, the perforated plate
15, the zone above perforated plate 15, optional spray systems and
other areas where the water is being heated with products of
combustion.
[0033] The combustion chamber annular space cooling flow discharge
can be routed to join the down corner flow as an alternate to
discharging directly into the combustion chamber. The combustion
chamber cooling flow discharge could also be piped to another
location.
[0034] Referring now to FIG. 2, the submerged combustion
cylindrical shaped water heating apparatus 10A is shown in FIG. 2.
The upper portion of the FIG. 2 water heating configuration is
similar to the FIG. 1 water heating configuration. The lower part
of the FIG. 2 arrangement includes the addition of an outlet water
liquid seal and weir assembly not included in the FIG. 1
arrangement. The water flowing across perforated plate 15
discharges into upper outlet water plenum 28. A weir plate 29
maintains the upper outlet water plenum 28 liquid level and
provides a vapor seal which prevents products of combustion from
bypassing perforated plate 15. The outlet water flows from upper
outlet water plenum 28 over weir 29 into center outlet water plenum
30. A liquid seal weir plate pan 31 maintains the center outlet
water plenum 30 liquid level and provides a vapor seal. The outlet
water flows from the center outlet water plenum 30 over the weir
plate pan 31 into the lower outlet water plenum 32. The vapor space
above lower outlet water plenum 32 is generally vented or open to
atmosphere (not shown). The lower outlet water plenum 32 includes
the heated water outlet which connects to heated water users. The
lower outlet plenum 32 can be modified to accommodate a snow
melting system. Other liquid level control means can be utilized to
maintain the outlet water plenum 28 and 30 liquid levels.
[0035] Refer now to FIG. 3, which is an elevation view cross
section of a spiral tube circuit LNG vaporizer utilizing the
submerged combustion water heater heat source. The lower portion of
FIG. 3 illustrates an embodiment teaching of Engdahl U.S.
Provisional Patent 60/516,845 SPIRAL TUBE LNG VAPORIZER. In
Provisional Patent 60/516,845 the submerged combustion heat source
water plenums have been arranged to connect and communicate with
the LNG vaporizer device plenums. The same water plenum arrangement
is depicted in FIG. 3. In FIG. 3 the water to be heated enters the
submerged combustion heat source via the submerged combustion water
inlet plenum 21. The water flows upward within the heat source
inlet plenum 21 to the horizontal inlet plenum 21 and into an
annular down corner 23 surrounding the combustion chamber. The
water exits the down corner through an orifice 24 and flows across
a radial perforated plate 15 where it is heated by products of
combustion passing through apertures in the perforated plate. A
plate arrangement as shown in FIG. 4 and described later provides
additional heat and mass transfer contact area between the water
and the products of combustion. The water exits the down corner
orifice at a high velocity and flows across the perforated plate as
a high velocity stream. The heated water is collected in the
submerged combustion heated water outlet plenum 26 and directed
downward through the vaporizer annular space containing the spiral
tube heat transfer circuits. The cooler water exiting the lower
portion of the annular space is circulated via the water circulator
to the submerged combustion heat source water inlet plenum 21 for
heating. The water circulator can be a propeller or axial flow
pump, a centrifugal pump, ejector pump, or another device to
circulate the water. The water circulator can be provided with a
variable speed driver.
[0036] The burner assembly 11 fires into the combustion chamber 12
and produces products of combustion gases. The products of
combustion flow from the combustion chamber through apertures in
the radial perforated plate 15. The products of combustion heat the
water flowing over the perforated plate. The products of combustion
exiting the perforated plate are collected in flue plenum 16 and
flow through the flue stack 20 to the atmosphere.
[0037] The LNG vaporizer device shown in the lower portion of FIG.
3 includes the LNG inlet manifold, the LNG vapor outlet manifold,
rows of spiral tube heat transfer circuits positioned within an
annular space and the outlet plenum. The spiral tube circuits can
also be installed with an interstage manifold. A portion of the
spiral tube circuits would connect to an inlet manifold on one end
and connect to an interstage manifold on the other end. Another
portion of the spiral tube circuits would connect to the interstage
manifold on one end and connect to an outlet manifold on the other
end. The interstage manifold can be designed as a separator to
collect and remove hydrocarbon liquids from the send out stream.
The rows of spiral tube heat transfer circuits are supported by
support bars. The spiral tube circuits are shown in the aligned
position in FIG. 3. Each tube within the spiral tube circuit is
placed generally vertically above each tube in the row below. The
spiral tube circuits can also be placed in the staggered position.
In the staggered position each tube within the spiral tube circuit
is placed generally above the gap in the row below. The vertical
spacing of the support rods is slightly larger than the sum of the
outside diameter of a heat transfer tube plus the diameter of a
support rod, providing vertical clearance such that movement of the
tubes is not restricted by the above support rods. The rows of
spiral tube circuits are not supported by tubes in the row below.
Each row is supported by its system of support rods. The tube is
not restricted from moving as it is cooled down or warmed up.
Independent movement is provided for each spiral tube circuit row.
Individual heat transfer tubes and circuits can cool down or warm
up at different rates without high thermal stresses. The tube
movement is generally in a radial direction. In some applications
that portion of the spiral tube circuit nearest the cold inlet
manifold will ice. The tube pitch of the tubes in a spiral tube
circuit is adjusted in the design as required to accommodate the
tube ice layer on the colder part of the spiral circuit. The tube
pitch can be adjusted to allocate heating medium flow. The water
circulator or pump is positioned in the outlet plenum. Several
water circulators can be utilized. The pump circulates the cooler
heating medium to the submerged combustion water inlet plenum
21.
[0038] The LNG vaporizer can be configured with several heat source
arrangements and several LNG heat transfer surface area
arrangements. The submerged combustion heat source can be located
above the heat transfer area or adjacent to the LNG heat transfer
surface area. The heat transfer surface area arrangements can
include a spiral tube arrangement, a helix arrangement, a
serpentine arrangement, or a shell and tube exchanger. The
configuration of Engdahl patent application Ser. No. 10/869,086 for
a RELIABLE LNG VAPORIZER can provide the LNG heat transfer area.
Piping may be required as extensions of the water plenums to
connect the various LNG heat transfer surface area arrangements to
the submerged combustion heat sources.
[0039] In the FIG. 3 arrangement, the submerged combustion heat
source is above the LNG heat transfer surface area. The products of
combustion do not impinge or contact the surface area. The pump
provides circulation of the heating medium rather than the products
of combustion used in traditional submerged combustion LNG
vaporizers for circulation.
[0040] FIG. 4 details an annular plate 33 connected to down corner
plate 25. Annular plate 33 is located to provide a flow passage
space between plate 33 and perforated plate 15. Annular plate 33
can also be provided as a plate with holes. The flow passage space
between plates 15 and 33 provides area for heat and mass transfer
contact between the products of combustion and the water to be
heated as the water flows outward in a generally radial direction.
The annular plate 33 can be installed in the submerged combustion
system FIG. 1, FIG. 2 and FIG. 3 arrangements.
[0041] The submerged combustion system FIG. 1, FIG. 2 and FIG. 3
arrangements can include one or more of the following control
functions (not shown in the figures):
[0042] Control means for varying the heated water outlet flow.
Control means for varying the flow can include valves, weirs and
variable flow pumps.
[0043] Control means for varying the inlet water flow. Control
means for varying the flow can include valves, weirs and variable
flow pumps.
[0044] In circulating loop and other applications, control means
are employed to maintain the loop water volume or change to a new
operating level. If the water volume is increasing or a lower
operating level is required, water is discharge water from the loop
to obtain the desired water level. If the level is decreasing,
make-up water is added to obtain the desired level. Water can also
be utilized for cooling when operating in the turndown mode.
[0045] Control means to maintain the water levels within operating
limits.
[0046] Burner control system including temperature control.
[0047] Additional operational, safety and shutdown functions are
included in the submerged combustion control systems.
[0048] The submerged combustion water heater can include several
arrangements and variations. Variations and arrangements can
include one of more of the following:
[0049] Water can be sprayed or injected into the products of
combustion resulting in the production of steam and cooling of the
products of combustion.
[0050] Baffles can be positioned in the heated water plenum to
assist in the removal of bubbles and entrainment in the heated
water.
[0051] Providing refractory insulation on the combustion
chamber.
[0052] Providing means to reduce the quantity of liquid droplets
leaving via the stack.
[0053] Providing means to control and maintain the pH of the water
and solutions within the heater.
[0054] Providing means to improve the air quality emissions from
the heater.
[0055] Contacting the products of combustion with a water spray
before the products of combustion are vented to atmosphere to
increase the heater efficiency.
[0056] Where the fluids to be heated include particulate
matter.
[0057] The FIG. 1, FIG. 2 and FIG. 3 arrangements can accommodate
water flows which vary in an operating range above and below the
design water flow. At higher water flows, the pressure in the down
corner 23 increases, resulting in an increased water orifice
opening 24 exit velocity and increased velocity of water flowing
across the perforated plate 15. At lower flows the water orifice
opening 24 exit velocity would decrease and decrease the velocity
of water flowing across perforated plate 15. The burner would turn
down to maintain the required water outlet temperature.
[0058] The submerged combustion system has design flexibility and
scalability to adapt to the requirements of the application. The
submerged combustion heater can be used for many commercial and
industrial applications. Some applications require modification of
the outlet plenum system. The submerged combustion system used for
snow melting would have a pan located to accept and melt snow.
Other shapes can also be utilized to configure the submerged
combustion system. They may not be as scaleable as the cylindrical
arrangement or provide the uniform distribution obtainable with the
cylindrical arrangement.
[0059] The heater has installation flexibility. It can be installed
below grade, above grade or partly below grade. It can be located
onshore and on offshore platforms.
[0060] Aqueous and other solutions can be concentrated in the
apparatus. The submerged combustion temperature is adjusted to
vaporize water or other fluids. The vaporized product leaves via
the stack. Provisions can be included to recover vaporized product
from the stack gases. The solution remaining in the apparatus is
concentrated.
[0061] The burner assembly is located in a dry area firing into a
large combustion chamber. The large combustion chamber can
accommodate a single high capacity, high efficiency, low
horsepower, low pressure burner assembly. The low pressure and low
submergence in the contact zone and other features of the submerged
combustion system reduce the potential for apparatus vibration. The
combustion chamber can also accommodate multiple burners. The
unique water and products of combustion flow and contact
arrangement permits the use of conventional low backpressure type
burner assemblies. The burner assembly backpressure would generally
be less than one pound per square inch.
[0062] The conventional burner assembly used in the invention can
more readily meet air quality regulations than the high back
pressure submerged combustion burner system. Several means are
available to reduce the products of combustion emissions from the
submerged combustion burner system. A high performance burner can
provide reduced emissions. A further reduction can be obtained by
recirculating products of combustion to the burner assembly to
reduce the SCV emissions. A products of combustion stream from the
flue plenum or flue stack can be recirculated to the burner. The
high efficiency submerged combustion heat source produces cool
products of combustion in the flue plenum and the flue stack. The
cool products of combustion can be recirculated to the burner
system. Some applications may require that the cool products of
combustion be heated before being recirculated to the burner. The
cool flue gas can be heated by indirect heat exchange with the hot
products of combustion. In another system the cool flue gas can be
heated by blending a portion of the hot products of combustion with
the cool flue gas to produce the required gas temperature for
recirculation. Another system would use cool products of combustion
or flue gas from an external source to lower the SCV emissions. The
external source of flue gas could be a gas turbine or another type
of fired facility. The arrangement using an external flue gas
source could increase the overall energy efficiency of the combined
system.
[0063] At start-up, the submerged combustion system water flow is
established before the burner is started. It is not necessary for
the air blower to displace water from a portion of the apparatus
before the burner is fired as required by many submerged combustion
systems. The time required for burner start-up is low. The total
start-up is low. The water flow configuration of the submerged
combustion system provides water heating with low pressure drop in
the water to be heated circuit.
[0064] Features
[0065] Several features of this invention Follow:
[0066] The unique gas and water flow arrangement provides an
effective means for heat and mass transfer surface area contact
between water and the products of combustion.
[0067] The burner start-up sequence can proceed without the air
blower displacing water. The submerged combustion system can be
quickly and easily started and shutdown.
[0068] The combustion gas system is configured to operate with low
back pressure. The combustion chamber and burner operate at low
pressure. The combustion air blower has low installed
horsepower.
[0069] The submerged combustion apparatus can provide the heat for
a complete system for vaporizing LNG and heating and vaporizing
other fluids.
[0070] The submerged combustion system facilitates the installation
of high efficiency, high capacity, single burners.
[0071] The low backpressure, low submergence heating system has
less potential for apparatus vibration.
[0072] The low pressure burner/combustion chamber arrangement can
more readily meet air quality regulations.
[0073] The submerged combustion system can be configured for
circulating loop applications and configured for once through
heating applications.
[0074] The submerged combustion system can concentrate
solutions.
[0075] The submerged combustion heater can be used for many
commercial and industrial applications.
[0076] The heater has installation flexibility. It can be installed
below grade, above grade or partly below grade. It can be located
onshore and on offshore platforms.
[0077] The heater provides fluid heating with low pressure drop in
the fluid to be heated circuit.
[0078] Numerous modifications and alternative embodiments of the
invention will be apparent to those skilled in the art in view of
the foregoing description. Accordingly, this description is to be
construed as illustrative only and is for the purpose of teaching
those skilled in the art the best mode of carrying out the
invention. The details of the apparatus may be varied substantially
without departing from the spirit of the invention, and the
exclusive use of all modifications which come within the scope of
the appended claims is reserved.
* * * * *