U.S. patent application number 10/305867 was filed with the patent office on 2003-11-06 for method for creating an air pressure.
Invention is credited to Walker, Thomas A..
Application Number | 20030206809 10/305867 |
Document ID | / |
Family ID | 46281634 |
Filed Date | 2003-11-06 |
United States Patent
Application |
20030206809 |
Kind Code |
A1 |
Walker, Thomas A. |
November 6, 2003 |
Method for creating an air pressure
Abstract
This invention provides a method of creating air pressure by
generating a source of air pressure greater than atmosphere air
pressure from a first rotary screw compressor. The first rotary
screw compressor has a first displacement and is driven by a first
power source. The generated source of air pressure from the first
rotary screw compressor is directed to a second rotary screw
compressor having a second displacement which is less than the
first displacement and which is driven by a second power source
which is independent of the first power source. The generated air
pressure from the second rotary screw compressor driven by the
second power source is greater than 200 psi.
Inventors: |
Walker, Thomas A.; (Berlin,
PA) |
Correspondence
Address: |
PAUL A. BECK & ASSOCIATES
SUITE 100
1575 McFARLAND ROAD
PITTSBURGH
PA
15216-1808
US
|
Family ID: |
46281634 |
Appl. No.: |
10/305867 |
Filed: |
November 27, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10305867 |
Nov 27, 2002 |
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10139106 |
May 3, 2002 |
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Current U.S.
Class: |
417/53 ;
417/244 |
Current CPC
Class: |
F04C 18/16 20130101;
F04C 23/001 20130101 |
Class at
Publication: |
417/53 ;
417/244 |
International
Class: |
F04B 001/00 |
Claims
I claim:
1. A method for creating an air pressure comprising: (a) generating
a source of air pressure greater than atmosphere air pressure from
a first rotary screw compressor having a first displacement and
which is driven by a first power source; (b) directing the
generated source of air pressure greater than atmosphere air
pressure to a second rotary screw compressor having a second
displacement which is less than the first displacement and which is
driven by a second power source which is independent of the first
power source; and (c) generating an air pressure greater than 200
psi from the second compressor driven by the second power
source.
2. The method as recited in claim 1 further comprising cooling and
removing water from the source of air pressure greater than
atmosphere before it is directed to the second rotary screw
compressor.
3 The method as recited in claim 2 further comprising passing the
source of air pressure greater than atmosphere through a separation
system prior to cooling and removing water from the source of air
pressure greater than atmosphere.
4. The method as recited in claim 1 including using a precooler to
cool the source of air pressure greater than atmosphere that will
cause water to condense out.
5. The method as recited in claim 4 including using a water
separator to remove water that has been condensed out.
6. A method for creating an air pressure comprising: (a) generating
a plurality of sources of air pressure each greater than atmosphere
air pressure from a plurality of first rotary screw compressors in
which together all of the first rotary screw compressors combined
have a total first displacement and in which each first compressor
is driven by its own first power source; (b) directing the
generated sources of air pressure greater than atmosphere air
pressure to a second rotary screw compressor having a second
displacement which is less than the total first displacement and
which is driven by a second power source which is independent of
the first power source; and (c) generating an air pressure greater
than 200 psi from the second compressor driven by the second power
source.
7. The method as recited in claim 6 further comprising cooling and
removing water from the sources of air pressure greater than
atmosphere before it is directed to the second rotary screw
compressor.
8. The method as recited in claim 7 further comprising passing the
source of air pressure greater than atmosphere through a separation
system prior to cooling and removing water from the source of air
pressure greater than atmosphere.
9. The method as recited in claim 6 including using a precooler to
cool the source of air pressure greater than atmosphere that will
cause water to condense out.
10. The method as recited in claim 9 including using a water
separator to remove water that has been condensed out.
11. A method for creating an air pressure of at least 500 psi
comprising: (a) generating a first air pressure of at least 167
psi; (b) cooling the first air pressure of at least 167 psi to
remove moisture and to cool the first air pressure; (c) providing a
rotary screw compressor with a 3:1 or less discharge to suction
compression ratio having its own lubrication system and a power
source; and (d) using the rotary screw compressor to increase the
cooled first air pressure to at least 500 psi.
12. A method as recited in claim 11 wherein the power source is an
engine of a carrier.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuation-in-part application of application
Ser. No. 10/139,106, filed May 3, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a method for creating an air
pressure greater than 200 psi. The invention utilizes air
compressors that are driven by a power source to create a desired
discharge air pressure greater than 200 psi.
[0004] 2. Description of the Related Art
[0005] There has been a need to increase air pressure produced from
existing rotary screw compressors. Equipment such as a
reciprocating booster is available to produce in excess of 200 psi
air pressure. Air pressure is produced from a number of primary
rotary screw compressors that take air in at atmospheric pressure
and increases it to between 100-350 psi air pressure. This
compressed air is then collectively fed to a reciprocating booster
which produces an output in excess of 200 psi (or 350 psi depending
on the air pressrure from the primary rotary screw compressor).
This equipment, namely the primary rotary screw compressors that
are used and the reciprocating booster each have their own separate
power source.
[0006] A common example of this setup would be in a typical oil or
gas drilling operation where 4120 cfm of air at 500 psi is
required. There would be 4 primary rotary screw compressors each
creating 1070 cfm of compressed air at 350 psi for a total of 4120
cfm at 350 psi. This 4120 cfm of compressed air at 350 psi is then
fed to a reciprocating booster compressor which discharges 4120 cfm
of air at 500 psi.
[0007] The reciprocating booster in the above identified equipment
has a considerable amount of moving components that wear and need
replaced frequently. This equipment is aging and is becoming
difficult to replace and to maintain because there are fewer
manufacturers in the market.
[0008] Others have decided that a solution would be to scrap the
primary rotary screw compressors and the reciprocating piston
booster and replace it with one large two stage rotary screw
compressor capable of discharging air at 500 psi with one large
power source.
[0009] There is a two stage rotary screw compressor driven by one
motor which is capable of producing 500 psi of air pressure. This
is on the market and is being sold by Ingersoll Rand. The model is
XXHP950/500. It has a rated speed of 1800 rpm driven by a 3412DIPA
Engine; rated at 560 horsepower.
[0010] This leaves a current user who has rotary screw compressors
each driven by a separate power source a choice of either trying to
rebuild the reciprocating booster or scrapping the existing
reciprocating booster which is useless and also scrapping otherwise
serviceable, maintainable, and replaceable parts for the various
primary rotary screw compressors which feed air to the
reciprocating booster and replacing it with a large two stage
rotary screw compressor. It is unacceptable economically to scrap
existing serviceable primary rotary screw compressors.
[0011] It is also economically unacceptable to use a large two
stage rotary screw stage compressor driven by one motor which is
capable of producing 500 psi because in order to create the same
volume of air that is needed you would need multiple two stage
rotary screw compressors each producing 500 psi. So for instance in
the above example of a typical oil or gas drilling operation one
would need (4) 1070 cfm 500 psi two stage rotary screw compressors
which is economically unfeasible.
[0012] Additionally, there are some problems with the use of a
large two stage rotary screw compressor driven by one motor to
produce 500 psi. One of the most significant problems that occur
when generating high pressure air is the condensation of water.
This is especially true when air pressure greater than 350 psi is
achieved.
[0013] When hot compressed air leaves the compression chamber of a
rotary screw compressor, water is held in the gas state. As the air
enters the receiver tank of the compressor, it expands and cools.
As this occurs the water condenses out and falls into the receiver
tank where the compressor lubricant is also held. Water in the
lubricant significantly reduces bearing life in a rotary screw
compressor.
[0014] The current art using a two stage rotary screw compressor
driven by one power source does not provide for cooling between the
first and second stage of the compressor. Water condenses as the
air enters the receiver tank. This water falls into the lubricant
and this mixture of water and lubricant greatly reduces bearing
life. In addition, the discharge air temperature of the air as it
leaves the second stage of the rotary screw compressor is very hot
in excess of 200 degrees Fahrenheit which reduces component life
and increases the cooling requirement of the compressor oil
coolers. The lubricant must be changed more often because water
condenses into the lubricant and it no longer has the same
lubricant qualities. In addition oil samples must be taken to
determine the water content of the oil.
[0015] It is impossible to remove water from the air stream between
the first and second stage by cooling in the current two stage
rotary screw compressor without also removing compressor lubricant.
In addition to water in the air, there is also compressor lubricant
in the air between the first and second stage compressor. If the
air temperature were reduced to remove the water the compressor
lubricant would also be removed. The compressor lubricant needs to
remain in the air mixture for lubrication and cooling as the air
enters the second stage.
SUMMARY OF THE INVENTION
[0016] The inventor has developed a method that is capable of
utilizing the existing primary compressors and feeding those
primary compressors to another compressor which has its own power
source. The additional compressor will replace the reciprocating
booster and can have the same output capability as the
reciprocating booster, namely greater than 200 psi and can be 500
psi or greater. The result is that the existing reciprocating
booster will be replaced by a rotary screw compressor capable of
providing an output in excess of 200 psi and can be 500 psi or
greater.
[0017] The present invention provides a method to enable a person
who already has a source of air pressure coming from primary
compressors and fed to a reciprocating piston booster to produce an
air pressure greater than 200 psi. Currently there is an abundance
of rotary screw compressors available. There has been a need to
increase the air pressure produced by the existing rotary screw
compressors and the need is even greater now because of the
problems associated with obtaining reciprocating booster
compressors and parts for reciprocating booster compressors.
[0018] The object of this invention is to provide a method to
enable a person who has an existing rotary screw compressor to
produce an air pressure greater than 200 psi. This is economically
advantageous because the person can use the existing equipment that
has already been paid for to generate air pressure from atmosphere
to up to between 100-350. The person only has to purchase another
rotary screw compressor having an independent motor with enough
horsepower to take the air pressure from between 100-350 to 500 psi
instead of paying for expensive equipment that produces air
pressure from atmosphere to 500 psi.
[0019] The inventor's solution enables one with existing primary
rotary screw compressors tied to a reciprocating booster to use the
primary rotary screw compressors with an additional rotary screw
compressor that has its own power source independent of any power
source from the primary rotary screw compressors.
[0020] Another object of the invention is to remove the water from
the air and to cool the air before it enters the second rotary
screw compressor and to reduce the temperature of the air generated
by the second screw compressor.
[0021] The inventor's solution eliminates the significant problem
of water condensation at higher pressures because water is removed
by a precooler from the air before it reaches the second
compressor.
[0022] This invention provides a method of creating air pressure by
generating a source of air pressure greater than atmosphere air
pressure from a first rotary screw compressor. The first rotary
screw compressor has a first displacement and is driven by a first
power source. The generated source of air pressure from the first
rotary screw compressor is directed to a second rotary screw
compressor having a second displacement which is less than the
first displacement and which is driven by a second power source
which is independent of the first power source. The generated air
pressure from the second rotary screw compressor driven by the
second power source is greater than 200 psi.
[0023] The generated source of air pressure from the first rotary
screw compressor can be cooled by a precooler before being directed
to the second rotary screw compressor. This causes the water to be
condensed out of the air stream prior to it entering the second
rotary screw compressor. The water can then be removed by a water
separator. It also causes the air temperature being input to the
second rotary screw compressor to be lowered and thus allowing a
lower output air temperature from the second rotary screw
compressor.
[0024] The generated source of air pressure greater than atmosphere
air pressure can be passed through a separation system prior to
being cooled and dried.
[0025] This invention also provides a method for creating an air
pressure by generating a plurality of sources of air pressure each
greater than atmosphere air pressure from a plurality of first
rotary screw compressors in which together all of the first screw
compressors combined have a total first displacement and in which
each first compressor is driven by its own first power source. The
generated sources of air pressure which are greater than atmosphere
air pressure are directed to a second rotary screw compressor
having a second displacement which is less than the total first
displacement and which is driven by a second power source which is
independent of the first power source. Air pressure greater than
200 psi is generated from the second compressor driven by the
second power source.
[0026] The generated sources of air pressure greater than
atmosphere can be cooled by a precooler before being directed to
the second rotary screw compressor. This causes the water to be
condensed out of the air stream prior to it entering the second
rotary screw compressor. A water separator can then remove the
water. The precooler also causes the air temperature being input to
the second rotary screw compressor to be lowered and thus allowing
a lower output air temperature from the second rotary screw
compressor.
[0027] The generated source of air pressure greater than atmosphere
air pressure can be passed through a separation system prior to
being cooled and dried.
[0028] This invention also provides a method for creating an air
pressure of at least 500 psi by generating a first air pressure of
at least 167 psi. The first air pressure of at least 167 psi is
cooled to remove moisture (i.e. water) and to cool the first air
pressure. Water can be removed from the first air pressure of at
least 167 psi. A rotary screw compressor with a 3:1 or less
discharge to suction compression ratio having its own lubrication
system and a power source is provided. The rotary screw compressor
is used to increase the cooled first air pressure to at least 500
psi. The rotary screw compressor's power source can be an engine of
a carrier.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1A diagrammatic rendition of the flow of one embodiment
of the method;
[0030] FIG. 2A second diagrammatic rendition of the flow of another
embodiment of the method;
[0031] FIG. 3A third diagrammatic rendition of the flow of another
embodiment of the method; and
[0032] FIG. 4A fourth diagrammatic rendition of the flow of another
embodiment of the method.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
Definitions
[0033] Air pressure--pressure measured in pounds per square inch
(p.s.i.) that air exerts on an object.
[0034] Generating a source of air pressure--a means of producing
air at a pressure greater than atmospheric pressure using an air
compressor which can be a rotary screw compressor.
[0035] Greater than atmosphere--an air pressure that is higher than
atmospheric pressure which is 14.7 lbs. per square inch at sea
level.
[0036] Rotary screw compressor--an air compressor consisting of a
male and female rotor. As the male rotor is driven, it rotates into
the female rotor and displaces a specific volume of air. This can
be a single or two stage compressor.
[0037] Displacement--the volume of air measured in cubic feet per
minute that is displaced by rotating male and female rotors in a
compressor.
[0038] Power source--the engine or motor that is driving the rotary
screw compressor.
[0039] Directing the generated source of air pressure--providing a
path for air to flow from a first rotary screw compressor to a
second rotary screw compressor or from primary screw compressors to
the second rotary screw compressor.
[0040] Less than the first displacement--the volume of the 2.sup.nd
rotary screw is less than the volume of the 1.sup.st rotary
screw.
[0041] Independent of the first power source--having it's own
source of power not connected in any way.
[0042] Plurality of first rotary screw compressors--more than one
first rotary screw compressor there may be many first rotary screw
compressors.
[0043] Total first displacement--the total displacement or sum of
all the displacements of the first rotary screw compressor or
compressors.
[0044] Its own first power source--a source of power for a first
rotary screw compressor.
[0045] Two stage compressor--a compressor having two compression
chambers, one compression chamber being smaller than the other.
[0046] Reciprocating booster--a piston compressor that takes in air
from another compressor and increases the pressure of that air.
[0047] Primary rotary screw compressor--refers to any or all of the
first rotary screw compressors used to supply air to the second
rotary screw compressor. It is an air compressor that takes in air
at atmosphere pressure and has a discharge air pressure rating up
to around 350 psi. It can be a single or two stage compressor. It
can also be a single compressor or a plurality of compressors.
[0048] Regulating/loading and unloading system--a system on an air
compressor that regulates speed of a power source, discharge
pressure, inlet pressure, discharge volume, and inlet volume. The
regulated variables are all interrelated and interconnected.
[0049] Separation system--The system on an air compressor that
removes oil from an air/oil mixture in a receiver tank before the
air is discharged from the compressor.
[0050] Cooling system--The system on an air compressor that cools a
compressor lubricant before it is reintroduced into the compressor.
Included in this system is a Filtration system for removing
contaminants from the oil.
[0051] Lubrication system--The systems on an air compressor which
is responsible for adequate lubrication of the compressor.
[0052] Receiver Tank--A tank located on an air compressor that
holds a compressed air/oil mixture and also contains a filter to
remove the oil from the air.
[0053] Discharge air pressure--A pressure of air after the air
leaves the receiver tank.
[0054] An engine of a carrier--The power source which provides
horsepower to operate the carrier which can be a truck. This engine
is separate from any deck mounted engine which may be mounted on
the carrier.
[0055] Generating a first air pressure of at least 167 psi--Air
pressure created by a primary compressor.
[0056] Cooling and removing water--Process whereby air, after being
compressed, is piped or plumbed through the tubes on a precooler.
Air is then forced over the tubes in the precooler by a fan. The
compressed air is cooled as it travels from inlet to outlet in the
precooler. As the air is cooled the water condenses out and is
removed by a condensate trap.
[0057] Remove moisture--Eliminating a majority of water from the
compressed air.
[0058] Cool the first air pressure--Reducing the temperature of the
first air pressure.
[0059] 3:1 or less discharge to suction compression ratio--Ratio of
the discharge pressure to the inlet pressure. It can be 3:1, 2:1,
or any range less than 3:1.
[0060] To cool--reducing the air temperature
[0061] Cause water to condense out--creating condition by which
water will be removed from an air stream
[0062] Water Separator--A mechanical device that removes water from
an air water/water mixture by using centrifugal force to spin out
water
DESCRIPTION
[0063] FIG. 1. is a block diagram of a method for generating air
pressure which shows a first rotary screw compressor 2 having a
first power source 4. The first rotary screw compressor 2 may be
called a primary compressor. The first rotary screw compressor 2
generates a source of air pressure 6 which is greater than
atmosphere pressure and which is directed to a second rotary screw
compressor 8 having a second independent power source 10. The
second rotary screw compressor 8 has a discharge air pressure 12
that is greater than 200 psi.
[0064] FIG. 2. is a block diagram of a method for generating air
pressure showing a plurality of first rotary screw compressors 2
each having its own first power source 4. The first rotary screw
compressors 2 can be referred to as primary compressors. The first
rotary screw compressors 2 have a combined total first
displacement. Each of the first rotary screw compressors 2
generates a source of air pressure 6 which is greater than
atmosphere pressure. Each source of air pressure 6 is directed to a
single second rotary screw compressor 8 having a displacement which
is less than the total first displacement. The second rotary screw
compressor has a second independent power source 10. The second
rotary screw compressor 8 generates discharge air pressure 12 which
is greater than 200 psi.
[0065] FIG. 3. is a block diagram of a method for generating air
pressure which shows a first rotary screw compressor 2 having a
first power source 4. The first rotary screw compressor 2 may be
called a primary compressor. The first rotary screw compressor 2
generates a source of air pressure 6 which is greater than
atmosphere pressure and which is directed to a precooler 14 that
reduces the air temperature. Water condenses out of the air as the
temperature is reduced. A water separator 15 removes the water so
that there is a cooled and dried source of air pressure greater
than atmosphere 16. The cooled and dried source of air pressure
greater than atmosphere 16 is directed to a second rotary screw
compressor 8 having a second independent power source 10. The
second rotary screw compressor 8 has a discharge air pressure 12
which is greater than 200 psi.
[0066] The source of air pressure 6 generated by the first rotary
screw compressor 2 can be at least 167 psi. The precooler 14 can
cool the source of air pressure 6 to remove moisture and to cool
the first air pressure 6. The second rotary screw compressor 8 can
be a compressor with a 3:1 or less discharge to suction compression
ratio having its own lubrication system and having a second
independent power source 10. The second independent power source 10
can be an engine of a carrier. For example, a crane carrier has its
own engine used to power the drive train of the carrier. This can
be used to provide power to the second rotary screw compressor 8.
The second rotary screw compressor 8 is used to increase the cooled
and dried source of air pressure greater than atmosphere 16 to at
least 500 psi.
[0067] FIG. 4. is a block diagram of a method for generating air
pressure showing a plurality of first rotary screw compressors 2
each having its own first power source 4. The first rotary screw
compressors 2 can be referred to as primary compressors. The first
rotary screw compressors 2 have a combined total first
displacement. Each of the first rotary screw compressors 2
generates a source of air pressure 6 which is greater than
atmosphere pressure. Each source of air pressure 6 is directed to a
single precooler 14 designed to handle the volume and pressure of
the air coming from the primary compressors that reduces the air
temperature. The sources of air pressure could alternatively be
directed to multiple precoolers (not shown in drawings) that reduce
the air temperature. Water is condensed out of the air as the
temperature is reduced. A water separator 15 removes the water so
that there is a cooled and dried source of air pressure greater
than atmosphere 16. The cooled and dried source of air pressure
greater than atmosphere 16 is directed to a second rotary screw
compressor 8 having a displacement which is less than the total
first displacement. The second rotary screw compressor has a second
independent power source 10. The second rotary screw compressor 8
generates discharge air pressure 12 which is greater than 200.
[0068] The above embodiments can also have a regulating/loading and
unloading system, a separation system, a cooling system, and/or a
lubrication system. These additional systems can operate in a
similar manner to the current systems used in existing air
compressors.
[0069] Most existing rotary screw compressors have a lubrication
system and a separation system. The lubrication system injects oil
into the compressor for lubrication and cooling. Thus as the
compressed air leaves the compressor it contains oil. The
separation system removes a vast majority of the oil from the
compressed air before the compressed air is discharged.
[0070] In FIGS. 3 and 4 it is beneficial for the first rotary screw
compressor 2 or the plurality of first rotary screw compressors 2
to have a lubrication system and a separation system and for the
second rotary screw compressor 8 to have its own lubrication and
separation system. If the primary compressors are equipped as
described then oil has been removed from the source of air pressure
greater than atmosphere pressure 6. This enables the precooler 14
to remove water only. The second rotary screw compressor 8 if
equipped as described above has its own lubrication system that
adds oil into the second rotary screw compressor. The separation
system for the second rotary screw compressor 8 removes oil from
the discharge air pressure greater than 200 psi 12.
[0071] The following is one example of how the invention could be
practiced:
[0072] 1) Connecting the generated source of air pressure from two
1070 CFM/350 psi (two stage) compressors each powered by a 465 hp
engine and having a separation system and a lubrication system to
produce one source of air pressure which is 2140 CFM at 350
psi;
[0073] 2) Directing the combined source of air pressure to a
precooler designed to handle volume and pressure of air coming from
the primary compressors thereby reducing the temperature so that a
majority of the water is condensed from the air and the water is
then removed by a water separator; and
[0074] 3) Directing the cooled and dried generated source of air
pressure to a second rotary screw compressor having an independent
power source. The second rotary screw compressor compresses the air
which is at 350 psi to 500 psi, and discharges air at 500 psi.
[0075] Various changes could be made in the above construction and
method without departing from the scope of the invention as defined
in the claims below. It is intended that all matter contained in
the above description as shown in the accompanying drawings shall
be interpreted as illustrative and not as a limitation.
* * * * *