WO2004018878A1 - Compressor with capacity control - Google Patents

Compressor with capacity control Download PDF

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Publication number
WO2004018878A1
WO2004018878A1 PCT/BE2003/000129 BE0300129W WO2004018878A1 WO 2004018878 A1 WO2004018878 A1 WO 2004018878A1 BE 0300129 W BE0300129 W BE 0300129W WO 2004018878 A1 WO2004018878 A1 WO 2004018878A1
Authority
WO
WIPO (PCT)
Prior art keywords
valve
pipe
inlet valve
inlet
piston
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/BE2003/000129
Other languages
French (fr)
Inventor
Wouter Van Praag
Paul Emmanuel Philomena Verbraeken
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Atlas Copco Airpower NV
Original Assignee
Atlas Copco Airpower NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Atlas Copco Airpower NV filed Critical Atlas Copco Airpower NV
Priority to EP03792051A priority Critical patent/EP1552155B1/en
Priority to BR0311403-1A priority patent/BR0311403A/en
Priority to CA002488874A priority patent/CA2488874C/en
Priority to AU2003254424A priority patent/AU2003254424B2/en
Priority to JP2004529601A priority patent/JP4022547B2/en
Priority to DE60307662T priority patent/DE60307662T2/en
Priority to US10/517,602 priority patent/US7607899B2/en
Publication of WO2004018878A1 publication Critical patent/WO2004018878A1/en
Anticipated expiration legal-status Critical
Priority to NO20051501A priority patent/NO337014B1/en
Ceased legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
    • F04C28/24—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
    • F04B49/22—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00 by means of valves
    • F04B49/225—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00 by means of valves with throttling valves or valves varying the pump inlet opening or the outlet opening
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
    • F04C18/08—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
    • F04C18/12—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
    • F04C18/14—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons
    • F04C18/16—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with toothed rotary pistons with helical teeth, e.g. chevron-shaped, screw type
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
    • F04C28/06—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids specially adapted for stopping, starting, idling or no-load operation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
    • F04C28/18—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by varying the volume of the working chamber
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2270/00—Control; Monitoring or safety arrangements
    • F04C2270/01—Load
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2270/00—Control; Monitoring or safety arrangements
    • F04C2270/58—Valve parameters

Definitions

  • the present invention concerns a compressor containing a compressor element which is provided with a rotor chamber onto which are connected an inlet pipe and an outlet pipe, a reservoir in the outlet pipe and a pressure regulating system comprising an inlet valve erected in the inlet pipe, a piston which is connected to the inlet valve and which can be moved in a cylinder, a bridge bridging said inlet valve and in which, between the inlet pipe and the rotor chamber, are successively erected a gas stream limiter and a non-return valve which only admits gas into the rotor chamber, and a gas pipe connecting the reservoir to the part of the bridge situated between the gas stream limiter and the non-return valve, and a relief valve erected in said gas pipe.
  • the pressure-regulating system described in the first paragraph also called a load and relief system, is one of the most frequently used regulating systems to allow for a production of compressed air from 0 to 100% with a minimum of energy loss.
  • the pressure regulating system makes sure that the inlet valve of the compressor element is closed.
  • the supply of inlet air is in this manner reduced to zero percent, and the compressor element will run idle.
  • the air supply at the outlet pipe, in particular at the reservoir which is usually erected in it, is stopped.
  • the pressure regulating system simultaneously activates a time switch which makes sure that the drive of the compressor element keeps on working for a certain period.
  • the pressure regulating system will order the drive to be stopped. If, however, a pressure difference occurs after the aforesaid period, the compressor element will keep on working and the pressure regulating system will order the inlet valve to be opened again, so that pressure can be built up again.
  • the pressure regulating system will order the compressor element to be started, whereby the inlet valve is opened.
  • the pressure regulating system contains a strong spring, built- in in the cylinder and pushing on the side of the piston which is turned towards the inlet valve, while the cylinder chamber situated on the other side of the piston is connected to the reservoir via a control line, equipped with an electromagnetic control valve.
  • the control valve When the rotors are driven at the initial start-up, the control valve is not excited, and the pressure in the reservoir is close to the atmospheric pressure.
  • the relief valve in the gas pipe is open and, under the influence of the spring on the piston, the inlet valve is closed. Due to the underpressure created in the rotor chamber, a small air flow will flow from the inlet pipe through the bridge, over the gas stream limiter and the non-return valve, to the rotor chamber, sufficient to provide for an increase of pressure in the reservoir.
  • a continuous air flow is created between the bridge, the rotor chamber, the reservoir and over the pneumatic relief valve which has been opened by the built-up pressure, and then back to the bridge.
  • the control valve is excited, as a result of which the relief valve goes back into the closed position, and the space above the piston in the cylinder is simultaneously put under pressure, and the spring force is overcome, such that the inlet valve is opened.
  • the production of compressed air now amounts to 100%.
  • the pressure is stabilised at the pressure for idle running, which is sufficient to provide for the injection of lubrication liquid on the rotors.
  • a small amount of air bridges the inlet valve and is sucked into the rotor chamber via the bridge and the non-return valve. The production of compressed air is reduced to a minimum and the compressor turns without producing anything.
  • the invention aims a compressor which does not have the above-mentioned disadvantages and which is thus relatively inexpensive, allows for an easy mounting and dismounting of the inlet valve and allows for a reliable control of the inlet valve .
  • the piston is a double-acting piston which divides the cylinder in two closed cylinder chambers, in that the cylinder chamber, on the side turned away from the inlet valve, is connected to a part of the rotor chamber situated near the inlet valve via a pipe, and in that, on the other side of the piston, the cylinder chamber is connected to a part of the rotor chamber situated near the inlet valve and to the non-return valve via a pipe.
  • the pipe connecting the cylinder chamber on the side which is turned away from the inlet valve to a part of the rotor chamber situated near the inlet valve may as such form the connection between the piston and the inlet valve, and it may for example consist of a stem provided with a duct over its entire length.
  • the relief valve may then, as in the known pressure regulating systems, be a pneumatic valve which is controlled by a pipe connected directly to the reservoir, a control line having a preferably electromagnetic control valve in it which is also connected to said reservoir, and a spring.
  • figure 1 schematically represents a compressor according to the invention
  • figure 2 schematically represents the pressure regulating system of the compressor from figure 1 during the start-up
  • figure 3 schematically represents the pressure regulating system of the compressor from figure 1, but when running idle
  • figure 4 represents a section of a practical embodiment of a part of the pressure regulating system from figures 2 and 3.
  • a screw-type compressor which mainly comprises a compressor element 1 which is provided with a rotor chamber
  • the pressure regulating system 8 has an inlet valve 9 with a valve element 10 which works in conjunction with a valve seat 11 in the valve housing 12.
  • the inlet valve 9 is bridged by a bridge 14 in which the inlet valve 3 and the inlet chamber 13 are successively provided, a gas stream limiter 15 and a non-return valve 16 which only allows a gas stream into the inlet chamber 13.
  • the part of the bridge 14 situated between the gas stream limiter 15 and the non-return valve 16 is connected to the reservoir 7 via a gas pipe 17.
  • a pneumatic relief valve 18 having an open position and a closed position.
  • the relief valve 18 is controlled by an electromagnetic control valve 19 in a control line 20 which is connected to the reservoir 7 or, as represented in figure 1, between this reservoir 7 and the relief valve 18, to the gas pipe 17 on the one hand, and which is connected to the far end of the relief valve 18 on the other hand, onto which also acts a spring 21.
  • a control line 20 which is connected to the reservoir 7 or, as represented in figure 1, between this reservoir 7 and the relief valve 18, to the gas pipe 17 on the one hand, and which is connected to the far end of the relief valve 18 on the other hand, onto which also acts a spring 21.
  • the pressure acts in the reservoir 7.
  • control valve 19 opens the control line 20, and in another position, it closes off said control line 20 on the side of the reservoir 7, while it connects the control line to the atmosphere on the side of the relief valve 18.
  • the pressure regulating system 8 further comprises a double-acting piston 23 which can be moved in a cylinder 24 and which divides this cylinder 24 in two closed cylinder chambers 25 and 26.
  • the piston 23 is connected to the valve element 10 of the inlet valve 9 by means of a stem 27, such that they move together.
  • the cylinder chamber 25 on the side of the piston 23 which is turned away from the inlet valve 9 is connected to the inlet chamber 13 via a pipe 28, whereas the other cylinder chamber 26 is connected to the part of the bridge 14 situated before the non-return valve 16 and the gas stream limiter 15 via a pipe 29 or, as is represented in figure 1, via the non-return valve 16 to the part of the gas pipe 17 connected onto this part of the bridge 14.
  • the motor 6 must easily reach its maximum speed. A small air flow flows out of the inlet pipe 3 via the bridge 14 into the rotor chamber 2, which is sufficient to build up a pressure in the reservoir 7.
  • the open relief valve 18 the pressure being built up in the reservoir 7 is also available in the cylinder chamber 26, as a result of which the piston 23 is being held in the top position, so that the inlet valve 9 remains closed.
  • the diameter of the valve element 10 and the diameter of the piston 23 are selected such that the vacuum forces exerted upon it compensate each other.
  • the reservoir 7 is no longer vented via said relief valve 18 and the gas pipe 17.
  • the cylinder chamber 26 is no longer connected to the reservoir 7, but to the inlet chamber 13 via the bridge 14 where there is an underpressure which also prevails in the cylinder chamber 25 via the pipe 28. Vacuum forces draw the valve element 10 into the open position. The result of the forces on the piston 23 and on the valve element 10 is a force which makes the inlet valve 9 open.
  • the compressor operates at full load, and the production of air amounts to 100%.
  • the pressure in the reservoir 7 will rise, and as soon as it reaches a specific value, the pressure regulating system will stop the excitation of the control valve 19, so that this control valve 19 interrupts the control line 20 again and brings the part thereof which is connected to the relief valve 18 in connection with the atmosphere.
  • the reservoir 7 is vented via the gas pipe 17, over the open relief valve 18 and the bridge 14, partly over the gas stream limiter 15 in the inlet pipe 3, and partly over the non-return valve 16 in the inlet chamber 13.
  • the pressure will stabilise at the pressure for idle running, which pressure is sufficient to provide for the injection of lubrication liquid on the rotors .
  • the compressor again not only sucks a small amount of air through the bridge 14, which amount of air flows back to the bridge 14 via the gas pipe 17.
  • the compressor in this manner keeps on running idle, without delivering compressed air.
  • the pressure in the reservoir 7 is measured by the pressure regulating system 8 and, when there has been no pressure drop, also the motor 6 will be stopped.
  • valve housing 12, the cylinder 24 and a far end 3A of the inlet pipe 3 have been united into a single housing 30 which is fixed on the rotor housing 32 by means of bolts 31. Also the inlet chamber 13 is present in this global housing 30 and forms a whole with an opening 33 in the rotor housing 32.
  • the two far ends of the bridge 14 are also ducts 14A and 14C provided in said body 30 and opening on the side of the far end 3A of the inlet pipe 3 in relation to the valve element 10, in the inlet chamber 13 respectively.
  • the gas pipe 29 is formed of a duct 29 provided in said housing 30 connecting the cylinder chamber 26 with a bridge 14 between duct 14B and 14C.
  • the pipe 28 is formed of the above-mentioned stem 27 upon which the piston 23 and the valve element 10 are fixed, and which is provided with a duct 34 over its entire length which opens into the cylinder chamber 25 on the one hand, and into the inlet chamber 13 or opening 33 on the other hand.
  • the gas which is compressed in the compressor must not necessarily be air. It may also be another gas, such as a gaseous cooling medium.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)
  • Rotary Pumps (AREA)
  • Control Of Eletrric Generators (AREA)

Abstract

Compressor containing a pressure regulating system (8) comprising an inlet valve (9); a piston (23) in a cylinder (24) connected thereto; a bridge (14) of this inlet valve (9) with a non-return valve (16) in it, characterized in that the piston (32) is a double-acting piston; the cylinder (24) on the side of the piston (23) turned away from the inlet valve is connected to a part (13) of the rotor chamber (2) situated near the inlet valve (9) via a pipe (28); and the cylinder (26) on the other side of the piston (23) is connected to the above-mentioned part (13) of the rotor chamber (2) and the non-return valve (16) via a pipe (29).

Description

COMPRESSOR ITH CAPACITY CONTROL
The present invention concerns a compressor containing a compressor element which is provided with a rotor chamber onto which are connected an inlet pipe and an outlet pipe, a reservoir in the outlet pipe and a pressure regulating system comprising an inlet valve erected in the inlet pipe, a piston which is connected to the inlet valve and which can be moved in a cylinder, a bridge bridging said inlet valve and in which, between the inlet pipe and the rotor chamber, are successively erected a gas stream limiter and a non-return valve which only admits gas into the rotor chamber, and a gas pipe connecting the reservoir to the part of the bridge situated between the gas stream limiter and the non-return valve, and a relief valve erected in said gas pipe.
Depending on certain parameters such as operating pressure, temperature, leakages, delivery or the like, or depending on a specific compressed air network and the length of the pipes, or also, depending on the type of application or the like, a certain type of compressor element will have to be selected which has to meet the total consumption under the worst conditions.
In reality, however, there will be variations in certain of the above-mentioned parameters. When the compressed air consumption is lower than the production, the pressure in the pipes will rise. When the operational pressure is reached in the network of pipes, the production of compressed air will be stopped in order to prevent unacceptable high pressures being created. After a while, the pressure in the pipes will reduce again due to leakages, consumption or the like and, depending on the application, pressure will have to be built up again in order to prevent the operational pressure from dropping under an unacceptable limit.
For compressors with rotors, such as screw-type compressors, the pressure-regulating system described in the first paragraph, also called a load and relief system, is one of the most frequently used regulating systems to allow for a production of compressed air from 0 to 100% with a minimum of energy loss.
In the case of such compressors, the variations in the consumption of compressed air are adjusted by opening and closing the inlet valve and the pressure relief in the reservoir.
As soon as the operational pressure reaches a certain level, the pressure regulating system makes sure that the inlet valve of the compressor element is closed. The supply of inlet air is in this manner reduced to zero percent, and the compressor element will run idle. The air supply at the outlet pipe, in particular at the reservoir which is usually erected in it, is stopped. When the inlet valve is closed, the pressure regulating system simultaneously activates a time switch which makes sure that the drive of the compressor element keeps on working for a certain period.
If no specific pressure difference occurs after this period, the pressure regulating system will order the drive to be stopped. If, however, a pressure difference occurs after the aforesaid period, the compressor element will keep on working and the pressure regulating system will order the inlet valve to be opened again, so that pressure can be built up again.
When the drive has come to a standstill and the pressure level in the outlet pipe is too low, the pressure regulating system will order the compressor element to be started, whereby the inlet valve is opened.
With known compressors of the above-mentioned type, the pressure regulating system contains a strong spring, built- in in the cylinder and pushing on the side of the piston which is turned towards the inlet valve, while the cylinder chamber situated on the other side of the piston is connected to the reservoir via a control line, equipped with an electromagnetic control valve.
When the rotors are driven at the initial start-up, the control valve is not excited, and the pressure in the reservoir is close to the atmospheric pressure. The relief valve in the gas pipe is open and, under the influence of the spring on the piston, the inlet valve is closed. Due to the underpressure created in the rotor chamber, a small air flow will flow from the inlet pipe through the bridge, over the gas stream limiter and the non-return valve, to the rotor chamber, sufficient to provide for an increase of pressure in the reservoir.
A continuous air flow is created between the bridge, the rotor chamber, the reservoir and over the pneumatic relief valve which has been opened by the built-up pressure, and then back to the bridge. When the drive is ready to run at full load, the control valve is excited, as a result of which the relief valve goes back into the closed position, and the space above the piston in the cylinder is simultaneously put under pressure, and the spring force is overcome, such that the inlet valve is opened. The production of compressed air now amounts to 100%.
When there is more production of compressed air than demanded, and the set pressure in the reservoir is maximal, the excitation of the electromagnetic control valve is stopped, as a result of which this is closed again. The space above the piston is connected to the atmosphere via the control valve, and the relief valve is opened again. As a result, the inlet valve is closed again under the influence of the spring, and the reservoir is vented via the relief valve, the gas pipe and the bridge.
After this venting, the pressure is stabilised at the pressure for idle running, which is sufficient to provide for the injection of lubrication liquid on the rotors. A small amount of air bridges the inlet valve and is sucked into the rotor chamber via the bridge and the non-return valve. The production of compressed air is reduced to a minimum and the compressor turns without producing anything.
As there is a strong spring in the inlet valve, special precautions have to be taken. The mounting and dismounting of the inlet valve is not without any danger because of said spring. Because of the spring, the inlet valve is also relatively expensive. In order to be able to relieve the spring pressure of the inlet valve, an expensive electromagnetic control valve with a large passage diameter is required.
When the relief valve and the inlet valve are controlled simultaneously, malfunctions sometimes occur.
The invention aims a compressor which does not have the above-mentioned disadvantages and which is thus relatively inexpensive, allows for an easy mounting and dismounting of the inlet valve and allows for a reliable control of the inlet valve .
According to the invention, this aim is reached in that the piston is a double-acting piston which divides the cylinder in two closed cylinder chambers, in that the cylinder chamber, on the side turned away from the inlet valve, is connected to a part of the rotor chamber situated near the inlet valve via a pipe, and in that, on the other side of the piston, the cylinder chamber is connected to a part of the rotor chamber situated near the inlet valve and to the non-return valve via a pipe. Thus, there is no action of a spring on the piston anymore.
The pipe connecting the cylinder chamber on the side which is turned away from the inlet valve to a part of the rotor chamber situated near the inlet valve may as such form the connection between the piston and the inlet valve, and it may for example consist of a stem provided with a duct over its entire length.
The relief valve may then, as in the known pressure regulating systems, be a pneumatic valve which is controlled by a pipe connected directly to the reservoir, a control line having a preferably electromagnetic control valve in it which is also connected to said reservoir, and a spring.
In order to better explain the characteristics of the invention, the following preferred embodiment of a compressor according to the invention is described as an example only without being limitative in any way, with reference to the accompanying drawings, in which:
figure 1 schematically represents a compressor according to the invention; figure 2 schematically represents the pressure regulating system of the compressor from figure 1 during the start-up; figure 3 schematically represents the pressure regulating system of the compressor from figure 1, but when running idle; figure 4 represents a section of a practical embodiment of a part of the pressure regulating system from figures 2 and 3.
The compressor which is schematically represented in figure
1 is a screw-type compressor which mainly comprises a compressor element 1 which is provided with a rotor chamber
2 onto which are connected an inlet pipe 3 on the one hand and an outlet pipe 4 on the other hand, and in which are erected two screw rotors 5 working in conjunction which are driven by a motor 6, a reservoir 7 which is erected in the outlet pipe and a pressure regulating system 8.
As is also represented in the figures 2 and 3, the pressure regulating system 8 has an inlet valve 9 with a valve element 10 which works in conjunction with a valve seat 11 in the valve housing 12.
There where the inlet pipe 3 opens into the rotor chamber 2, the latter forms a protruding inlet chamber 13 in which the valve element 10 is in the open position.
The inlet valve 9 is bridged by a bridge 14 in which the inlet valve 3 and the inlet chamber 13 are successively provided, a gas stream limiter 15 and a non-return valve 16 which only allows a gas stream into the inlet chamber 13.
The part of the bridge 14 situated between the gas stream limiter 15 and the non-return valve 16 is connected to the reservoir 7 via a gas pipe 17. In this gas pipe 17 is erected a pneumatic relief valve 18 having an open position and a closed position.
The relief valve 18 is controlled by an electromagnetic control valve 19 in a control line 20 which is connected to the reservoir 7 or, as represented in figure 1, between this reservoir 7 and the relief valve 18, to the gas pipe 17 on the one hand, and which is connected to the far end of the relief valve 18 on the other hand, onto which also acts a spring 21. On the other far end, which is connected to the reservoir 7 or the part of the gas pipe 17 situated between the relief valve 18 and said reservoir 7 via a pipe 22, the pressure acts in the reservoir 7.
In one position, the control valve 19 opens the control line 20, and in another position, it closes off said control line 20 on the side of the reservoir 7, while it connects the control line to the atmosphere on the side of the relief valve 18.
The pressure regulating system 8 further comprises a double-acting piston 23 which can be moved in a cylinder 24 and which divides this cylinder 24 in two closed cylinder chambers 25 and 26. The piston 23 is connected to the valve element 10 of the inlet valve 9 by means of a stem 27, such that they move together.
The cylinder chamber 25 on the side of the piston 23 which is turned away from the inlet valve 9 is connected to the inlet chamber 13 via a pipe 28, whereas the other cylinder chamber 26 is connected to the part of the bridge 14 situated before the non-return valve 16 and the gas stream limiter 15 via a pipe 29 or, as is represented in figure 1, via the non-return valve 16 to the part of the gas pipe 17 connected onto this part of the bridge 14.
When the compressor is initially started up, the pressure in the reservoir 7 is close to the atmospheric pressure. The control valve 19 is not excited and the part of the control line 20 connected to the relief valve 18 is connected to the atmosphere such that, under the influence of the spring 21, the relief valve is closed and closes off the gas pipe 17.
The motor 6 must easily reach its maximum speed. A small air flow flows out of the inlet pipe 3 via the bridge 14 into the rotor chamber 2, which is sufficient to build up a pressure in the reservoir 7.
When the pressure being built up in the reservoir 7, which acts on the relief valve 18 via the pipe 22, neutralises the operation of the spring 21, the relief valve 18 will go into its open position, as represented in figure 2.
Thanks to the open relief valve 18, the pressure being built up in the reservoir 7 is also available in the cylinder chamber 26, as a result of which the piston 23 is being held in the top position, so that the inlet valve 9 remains closed. There is an underpressure in the inlet chamber 13, as a result of which the valve element 10 is drawn open, but this force is compensated because the same underpressure prevails in the cylinder chamber 25 via the pipe 28. The diameter of the valve element 10 and the diameter of the piston 23 are selected such that the vacuum forces exerted upon it compensate each other.
There is a continuous air flow from the reservoir 7, over the open relief valve 18 and the bridge 14 and the compressor element 1, and back to the reservoir 7.
When the motor 6 is ready for a full load, the electromagnetic control valve 19 is excited, as a result of which the control line 20 opens, as represented in figure 3.
The pressure of the reservoir 7 now acts, via the control line 20 on the one hand and via the pipe 22 on the other hand, on the relief valve 18, and the spring 21 will push the relief valve 18 into the closed position, as is also represented in figure 3.
As a result, the reservoir 7 is no longer vented via said relief valve 18 and the gas pipe 17. The cylinder chamber 26 is no longer connected to the reservoir 7, but to the inlet chamber 13 via the bridge 14 where there is an underpressure which also prevails in the cylinder chamber 25 via the pipe 28. Vacuum forces draw the valve element 10 into the open position. The result of the forces on the piston 23 and on the valve element 10 is a force which makes the inlet valve 9 open.
The compressor operates at full load, and the production of air amounts to 100%. When the production of compressed air exceeds the demand, the pressure in the reservoir 7 will rise, and as soon as it reaches a specific value, the pressure regulating system will stop the excitation of the control valve 19, so that this control valve 19 interrupts the control line 20 again and brings the part thereof which is connected to the relief valve 18 in connection with the atmosphere.
As described for the start-up, the relief valve 18 will as a result thereof go into its open position, and the inlet valve 9 will close again. The condition as represented in figure 2 is created again.
The reservoir 7 is vented via the gas pipe 17, over the open relief valve 18 and the bridge 14, partly over the gas stream limiter 15 in the inlet pipe 3, and partly over the non-return valve 16 in the inlet chamber 13.
After this venting, the pressure will stabilise at the pressure for idle running, which pressure is sufficient to provide for the injection of lubrication liquid on the rotors .
The compressor again not only sucks a small amount of air through the bridge 14, which amount of air flows back to the bridge 14 via the gas pipe 17. The compressor in this manner keeps on running idle, without delivering compressed air. After a pre-programmed length of time, the pressure in the reservoir 7 is measured by the pressure regulating system 8 and, when there has been no pressure drop, also the motor 6 will be stopped.
In case of a pressure drop in the reservoir 7 as a result of a diminution of air, the motor 6 will keep on running and the pressure regulating system 8 will excite the control valve 19 again, so that the condition as represented in figure 3 is created again, with an open inlet valve 9 in the above-described manner.
By making use of the above-described pressure-regulating system 8, it is possible to use a inexpensive electromagnetic control valve 19 with a small passage, and the relief valve 18 will be more reliable as the air flow, through the control valve 19, only has to control said relief valve 18 and not the piston 23 in the cylinder 24.
Moreover, it is not necessary to use a heavy spring acting on the piston, which is safe and non-expensive, and as a result of which the cylinder 24 can be made compact.
How the cylinder 24 and the inlet valve 9 as a whole can be made very compact in practice is represented in figure 4.
The valve housing 12, the cylinder 24 and a far end 3A of the inlet pipe 3 have been united into a single housing 30 which is fixed on the rotor housing 32 by means of bolts 31. Also the inlet chamber 13 is present in this global housing 30 and forms a whole with an opening 33 in the rotor housing 32.
The two far ends of the bridge 14 are also ducts 14A and 14C provided in said body 30 and opening on the side of the far end 3A of the inlet pipe 3 in relation to the valve element 10, in the inlet chamber 13 respectively.
The gas pipe 29 is formed of a duct 29 provided in said housing 30 connecting the cylinder chamber 26 with a bridge 14 between duct 14B and 14C.
In this compact embodiment, the pipe 28 is formed of the above-mentioned stem 27 upon which the piston 23 and the valve element 10 are fixed, and which is provided with a duct 34 over its entire length which opens into the cylinder chamber 25 on the one hand, and into the inlet chamber 13 or opening 33 on the other hand.
It is clear that the gas which is compressed in the compressor must not necessarily be air. It may also be another gas, such as a gaseous cooling medium.
The present invention is by no means limited to the above- described embodiment given as an example and represented in the accompanying drawings; on the contrary, such a compressor can be made in different shapes and dimensions while still remaining within the scope of the invention.

Claims

Claims .
1. Compressor containing a compressor element (1) which is provided with a rotor chamber (2) onto which are connected an inlet pipe (3) and an outlet pipe (4); a reservoir (7) in the outlet pipe (4); a pressure regulating system (8) comprising an inlet valve (9) erected in the inlet pipe (3) ; a piston (23) which is connected to the inlet valve (9) and which can be moved in a cylinder (24) ; a bridge (14) bridging said inlet valve (9) and in which, between the inlet pipe (3) and the rotor chamber (2), are successively erected a gas stream limiter (15) and a non- return valve (16) which only admits gas into the rotor chamber (2); a gas pipe (17) connecting the reservoir (7) to the part of the bridge (14) situated between the gas stream limiter (15) and the non-return valve (16) ; and a relief valve (18) erected in said gas pipe (17), characterized in that the piston (23) is a double-acting piston which divides the cylinder (24) in two closed cylinder chambers (25,26); in that the cylinder chamber
(25) , on the side turned away from the inlet valve, is connected to a part (13) of the rotor chamber (2) situated near the inlet valve (9) via a pipe (28); and in that, on the other side of the piston (23) , the cylinder chamber
(26) is connected to a part (13) of the rotor chamber (2) situated near the inlet valve (9) and to the non-return valve (16) via a pipe (29) .
2. Compressor according to claim 1, characterised in that the pipe (28) connecting the cylinder chamber (25) on the side which is turned away from the inlet valve (9) to a part (13) of the rotor chamber (2) situated near the inlet valve (9) as such forms the connection (27) between the piston (23) and the inlet valve (9) .
3. Compressor according to claim 2, characterised in that the connection between the piston (23) and the inlet valve (9) consists of a stem (27) provided with a duct (34) over its entire length.
4. Compressor according to any of the preceding claims, characterised in that the relief valve (18) is a pneumatic valve which is equipped with a spring (21) and which is connected by a pipe (22) which is directly connected to the reservoir (7) and a control line (20) which is also connected to said reservoir (7) via a control valve (19) .
5. Compressor according to claim 4, characterised in that the control valve (19) is an electromagnetic valve.
6. Compressor according to any of the preceding claims, characterised in that the inlet valve (9) has a housing (12) forming a common housing (30) with the cylinder (24) .
PCT/BE2003/000129 2002-08-22 2003-07-24 Compressor with capacity control Ceased WO2004018878A1 (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
EP03792051A EP1552155B1 (en) 2002-08-22 2003-07-24 Compressor with capacity control
BR0311403-1A BR0311403A (en) 2002-08-22 2003-07-24 Capacity control compressor
CA002488874A CA2488874C (en) 2002-08-22 2003-07-24 Compressor with capacity control
AU2003254424A AU2003254424B2 (en) 2002-08-22 2003-07-24 Compressor with capacity control
JP2004529601A JP4022547B2 (en) 2002-08-22 2003-07-24 Compressor with capacity controller
DE60307662T DE60307662T2 (en) 2002-08-22 2003-07-24 COMPRESSOR WITH POWER CONTROL
US10/517,602 US7607899B2 (en) 2002-08-22 2003-07-24 Compressor with capacity control
NO20051501A NO337014B1 (en) 2002-08-22 2005-03-21 Compressor with capacity control.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
BE2002/0495A BE1015079A4 (en) 2002-08-22 2002-08-22 Compressor with pressure relief.
BE2002/0495 2002-08-22

Publications (1)

Publication Number Publication Date
WO2004018878A1 true WO2004018878A1 (en) 2004-03-04

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US (1) US7607899B2 (en)
EP (1) EP1552155B1 (en)
JP (1) JP4022547B2 (en)
KR (1) KR100715965B1 (en)
CN (1) CN100354526C (en)
AT (1) ATE336661T1 (en)
AU (1) AU2003254424B2 (en)
BE (1) BE1015079A4 (en)
BR (1) BR0311403A (en)
CA (1) CA2488874C (en)
DE (1) DE60307662T2 (en)
ES (1) ES2271687T3 (en)
NO (1) NO337014B1 (en)
PT (1) PT1552155E (en)
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007019651A3 (en) * 2005-08-17 2007-04-12 Atlas Copco Airpower Nv Improved device for adjusting the flow rate of a mobile oil- injected screw-type compressor.
IT202200008156A1 (en) * 2022-04-26 2023-10-26 Virgilio Mietto IMPROVED VOLUMETRIC COMPRESSOR
US11841718B1 (en) 2022-07-08 2023-12-12 Ingersoll-Rand Industrial U.S., Inc. Pneumatic inlet/blowdown valve assembly

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2611601C (en) * 2005-07-07 2011-10-04 Bgm Innovations Limited Adaptor for an air compressor and an air compressor
DE102011084811B3 (en) * 2011-10-19 2012-12-27 Kaeser Kompressoren Ag Gas inlet valve for a compressor, compressor with such a gas inlet valve and method for operating a compressor with such a gas inlet valve
US10202968B2 (en) * 2012-08-30 2019-02-12 Illinois Tool Works Inc. Proportional air flow delivery control for a compressor
BE1021737B1 (en) * 2013-09-11 2016-01-14 Atlas Copco Airpower, Naamloze Vennootschap LIQUID-INJECTED SCREW COMPRESSOR, CONTROL FOR THE TRANSITION FROM AN UNLOADED TO A LOAD SITUATION OF SUCH SCREW COMPRESSOR AND METHOD APPLIED THEREOF
CN104976119B (en) * 2014-04-04 2017-01-18 艾默生环境优化技术有限公司 Temperature control system and method of compressor
US10180138B2 (en) 2014-04-04 2019-01-15 Emerson Climate Technologies, Inc. Compressor temperature control systems and methods
JP6513345B2 (en) * 2014-07-03 2019-05-15 ナブテスコ株式会社 Air compressor
DE102014010534A1 (en) * 2014-07-19 2016-01-21 Gea Refrigeration Germany Gmbh screw compressors
DE102016011495A1 (en) 2016-09-21 2018-03-22 Knorr-Bremse Systeme für Nutzfahrzeuge GmbH Screw compressor for a commercial vehicle
WO2018234910A1 (en) 2017-06-21 2018-12-27 Atlas Copco Airpower, Naamloze Vennootschap INTAKE VALVE FOR THE INPUT OF A COMPRESSOR ELEMENT AND COMPRESSOR AND COMPRESSOR ELEMENT EQUIPPED WITH SUCH AN INTAKE VALVE
CN108194364B (en) * 2017-12-29 2023-07-14 珠海格力节能环保制冷技术研究中心有限公司 Compressor
US11493033B2 (en) * 2018-11-20 2022-11-08 Clark Equipment Company Low energy idling for a compressed air system
BE1027005B9 (en) * 2019-01-30 2020-10-19 Atlas Copco Airpower Nv Method of controlling a compressor to an unloaded state
DE102020121963A1 (en) 2020-08-21 2022-02-24 Bürkert Werke GmbH & Co. KG compressor system
CN115596667B (en) * 2022-11-09 2023-08-11 爱景智能装备(无锡)有限公司 Air inlet adjusting structure and method of double-screw compressor

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4406589A (en) * 1980-02-29 1983-09-27 Tokico Ltd. Compressor
GB2133585A (en) * 1983-01-13 1984-07-25 Hoerbiger Ventilwerke Ag A screw compressor control arrangement
US4708599A (en) * 1984-05-25 1987-11-24 Hitachi, Ltd. Rotary compressor apparatus
EP1004774A2 (en) * 1993-10-29 2000-05-31 Ateliers François s.a. Tank mounted rotary compressor
BE1012655A3 (en) * 1998-12-22 2001-02-06 Atlas Copco Airpower Nv Working method for the control of a compressor installation and compressorinstallation controlled in this way

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3105630A (en) * 1960-06-02 1963-10-01 Atlas Copco Ab Compressor units
US3367562A (en) * 1966-06-23 1968-02-06 Atlas Copco Ab Means for unloading and controlling compressor units
US3788776A (en) * 1972-08-10 1974-01-29 Gardner Denver Co Compressor unloading control
US4068980A (en) * 1976-10-01 1978-01-17 Gardner-Denver Company Compressor startup control
IT1103276B (en) * 1977-05-25 1985-10-14 Hydrovane Compressor OIL SEAL CAPSULISING COMPRESSOR
JPS5612093A (en) * 1979-07-10 1981-02-05 Tokico Ltd Oil cooled compressor
DE3211598A1 (en) * 1982-03-30 1983-11-03 Daimler-Benz Ag, 7000 Stuttgart PISTON AIR PRESSER
JPS6060293A (en) * 1983-09-12 1985-04-06 Hitachi Ltd Single stage oil-less type rotary compressor
GB2147363B (en) * 1983-09-28 1987-02-11 Hydrovane Compressor Positive displacement rotary compressors
JPS60101295A (en) * 1983-11-08 1985-06-05 Sanden Corp Compression capacity varying type scroll compressor
GB2167130B (en) * 1984-11-19 1988-01-13 Hydrovane Compressor Rotary positive displacement air compressor
US4998862A (en) * 1989-10-02 1991-03-12 Ingersoll-Rand Company Air compressor pressure regulating valve system
US5318151A (en) * 1993-03-17 1994-06-07 Ingersoll-Rand Company Method and apparatus for regulating a compressor lubrication system
BE1011782A3 (en) * 1998-03-10 2000-01-11 Atlas Copco Airpower Nv Compressor unit and taking control device used.
BE1013293A3 (en) * 2000-02-22 2001-11-06 Atlas Copco Airpower Nv Method for controlling a compressor installation and thus controlled compressor installation.
BE1014297A3 (en) * 2001-07-13 2003-08-05 Atlas Copco Airpower Nv Water injected screw compressor.

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4406589A (en) * 1980-02-29 1983-09-27 Tokico Ltd. Compressor
GB2133585A (en) * 1983-01-13 1984-07-25 Hoerbiger Ventilwerke Ag A screw compressor control arrangement
US4708599A (en) * 1984-05-25 1987-11-24 Hitachi, Ltd. Rotary compressor apparatus
EP1004774A2 (en) * 1993-10-29 2000-05-31 Ateliers François s.a. Tank mounted rotary compressor
BE1012655A3 (en) * 1998-12-22 2001-02-06 Atlas Copco Airpower Nv Working method for the control of a compressor installation and compressorinstallation controlled in this way

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007019651A3 (en) * 2005-08-17 2007-04-12 Atlas Copco Airpower Nv Improved device for adjusting the flow rate of a mobile oil- injected screw-type compressor.
US8303264B2 (en) 2005-08-17 2012-11-06 Atlas Copco Airpower, Naamloze Vennootschap Device for adjusting the flow rate of a mobile oil-injected screw-type compressor
IT202200008156A1 (en) * 2022-04-26 2023-10-26 Virgilio Mietto IMPROVED VOLUMETRIC COMPRESSOR
US11841718B1 (en) 2022-07-08 2023-12-12 Ingersoll-Rand Industrial U.S., Inc. Pneumatic inlet/blowdown valve assembly
EP4303443A1 (en) * 2022-07-08 2024-01-10 Ingersoll-Rand Industrial U.S., Inc. Pneumatic inlet/blowdown valve assembly
US12468321B2 (en) 2022-07-08 2025-11-11 Ingersoll-Rand Industrial U.S., Inc. Pneumatic inlet/blowdown valve assembly

Also Published As

Publication number Publication date
DE60307662D1 (en) 2006-09-28
ATE336661T1 (en) 2006-09-15
CA2488874A1 (en) 2004-03-04
JP4022547B2 (en) 2007-12-19
AU2003254424A1 (en) 2004-03-11
BR0311403A (en) 2005-03-15
JP2005536674A (en) 2005-12-02
KR20050056980A (en) 2005-06-16
NO20051501L (en) 2005-03-21
KR100715965B1 (en) 2007-05-09
EP1552155A1 (en) 2005-07-13
PT1552155E (en) 2006-12-29
CN100354526C (en) 2007-12-12
CA2488874C (en) 2008-04-29
CN1668852A (en) 2005-09-14
AU2003254424B2 (en) 2009-02-19
US20060018769A1 (en) 2006-01-26
ES2271687T3 (en) 2007-04-16
NO337014B1 (en) 2015-12-28
BE1015079A4 (en) 2004-09-07
US7607899B2 (en) 2009-10-27
EP1552155B1 (en) 2006-08-16
DE60307662T2 (en) 2007-08-23

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