US3582233A - Rotary compressor control system - Google Patents

Rotary compressor control system Download PDF

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Publication number
US3582233A
US3582233A US819011A US3582233DA US3582233A US 3582233 A US3582233 A US 3582233A US 819011 A US819011 A US 819011A US 3582233D A US3582233D A US 3582233DA US 3582233 A US3582233 A US 3582233A
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Prior art keywords
compressor
bleeddown
pressure
air tank
oil air
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US819011A
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Carl Bloom
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Studebaker Worthington Inc
Atlas Copco Holyoke Inc
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Worthington Corp
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Assigned to STUDEBAKER WORTHINGTON, INC. A CORP. OF DE reassignment STUDEBAKER WORTHINGTON, INC. A CORP. OF DE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: WORTHINGTON COMPRESSORS, INC.
Assigned to ATLAS COPCO MANUFACTURING, INC., A CORP. OF DE reassignment ATLAS COPCO MANUFACTURING, INC., A CORP. OF DE ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: STUDEBAKER-WORTHINGTON, INC.
Assigned to ATLAS COPCO HOLYOKE INC. reassignment ATLAS COPCO HOLYOKE INC. CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). JUNE 18, 1980 Assignors: ATLAS COPCO MANUFACTURING, INC.
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    • 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
    • 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

Definitions

  • ABSTRACT New and improved rotary compressor control
  • Int. Cl F04b 49/00 means are provided and include means to prevent restarting of [50] Fleld of Search 230/6, 17, the compressor motor against a high pressure load in the 207, 208; 417/17, 27, 2 418/100 pressor discharge system, and means to maintain a flow of air through the compressor during unloaded operation of the [56] References cued latter.
  • means are provided to substantially attenu- UNITED STATES PATENTS ate the operational noise level of the compressor, and the 2, 941 l2 i lg V 230/25 discomforting effects thereof upon operating personnel.
  • This invention relates to a new and improved control system for rotary compressors and, more particularly, to a rotary compressor control system for controlling, in interrelated manner, the loading and unloading thereof and the starting and stopping of the compressor.
  • the compressor is required to frequently restart against a high-pressure load in the compressor discharge system with resultant possibility of damage to the blades of the rotary compressor, and undesirable high initial torque demand and attendant and similarly undesirable high initial electrical power demand on the electrical system which powers the compressor.
  • many of the prior art rotary compressor control systems substantially discontinue the flow of air through the compressor during unloaded operation thereof with resultant undesirable effect upon the compressor lubrication system and the operation of compressor safety devices in the nature, for example, of discharge air temperature sensing means.
  • Another object of this invention is the provision of a rotary compressor control system as above which prevent compressor restarts against high-pressure loads in the compressor discharge system.
  • Another object of this invention is the provision of a rotary compressorcontrol system as above which functions to provide for some flow of air through the compressorduring unloaded operation to insure adequate compressor lubrication and effective operation of compressor safety devices.
  • Another object of this invention is the provision of a rotary compressor control system as above which substantially reduces the operational noise level of the compressor and the aggravating effects thereof upon operating personnel.
  • a further object of this invention is the provision of a rotary compressor control system as above which requires the use of only readily available components of proven dependability in the fabrication thereof to thus provide for long periods of satisfactory, maintenance-free control system operation under demanding operational conditions.
  • a still further object of this invention is the provision of a rotary compressor control system which provides all of the sig nificant advantages stipulated above at relatively low cost.
  • the new and improved rotary compressor control system of the invention is for application to a rotary compressor having a compressor suction control for loading and unloading the compressor, an oil air tank connected to the compressor discharge for compressor lubrication purposes, an air storage tank connected to the discharge of the oil air tank, and pressure responsive control means operatively associated with the air storage tank and the ener' gization circuit for the compressor motor and effective to respectively operate the compressor suction control to load and unload said compressor, and to start and stop said com- I pressor motor, in response to the pressure in the air storage tank.
  • control system of the invention comprises a restricted conduit which is effective, upon compressor-unloading operation of the pressure responsive control means, to bleeddown the oil air tank through the compressor suction control at a predetermined rate, and an air injection conduit which is concomitantly operable to inject air into the compressor inlet to maintain a flow of air through the compressor during unloaded operation thereof.
  • pressure responsive means which are operatively associated with the oil air tank and are operable to prevent stopping of the compressor by the pressure responsive control means until the pressure in the oil air tank has been bled down to a predetermined level.
  • the system of the invention comprises a variable restriction in the oil'air tank bleeddown conduit, and said variable restriction is effective to bleeddown the oil air tank at a variable rate in accordance with the pressure in the latter.
  • FIG. 1 is a schematic flow diagram of a representative, ro-
  • FIG. 2 is a circuit diagram of the control circuit for use with the control system of FIG. 1;
  • FIG. 3 is a schematic flow diagram of a first form of a rotary compressor control system constructed and operative in accordance with the teachings of this invention
  • FIG. 4 is a circuit diagram of the control circuit for use with the control system of FIG. 3;
  • FIG. 5 is a schematic flow diagram of a second form of a rotary compressor control system constructed and operative in accordance with the teachings of this invention
  • FIG. 6 is a longitudinal cross-sectional view taken through the controlled restriction bleeddown valve of the system of FIG. 5 in a first position thereof;
  • FIG. 7 is a longitudinal cross-sectional view taken through the controlled restriction bleeddown valve of FIG. 5 in a second position thereof.
  • FIG. 1 DESCRIPTION OF THE PRIOR ART
  • a rotary compressor 10 comprising conventional compressor suction control means 12 which are, of course, effective to load and unload the former.
  • the suction control means 12 include a compressor air inlet conduit 13 connected thereto, and suitable air filter means 14 are connected as shown in the said air inlet conduit for obvious purpose.
  • a discharge conduit 15 connects the discharge of the rotary compressor 10 to an oil air tank 16, and demister means 18 are operatively associated with the latter in conventional manner.
  • An air storage tank is indicated at 20, and a conduit 22, including a check valve 24 connected therein as shown, connects the demister 18 to the said air storage tank.
  • a double contact, normally closed pressure switch is indicated at PS-A and may be seen to be operatively connected to the air storage tank 20 by conduit 26 so as to be responsive to the pressure in the former.
  • a three-way solenoid valve is indicated at 28 and is connected as shown, by conduits 30 and 32, respectively, to the air storage tank 20 and the compressor suction control means 12.
  • the three-way solenoid valve 28 includes a vent port as indicated at 33 which is effective to vent the same to atmosphere.
  • An oil air tank bleeddown valve is indicated at 34 and is connected as shown to the demister 18 by a conduit 36, and to the conduit 32 by a conduit 38.
  • the said bleeddown valve includes a bleed port 40 which is effective to bleed the valve to atmosphere.
  • Temperature responsive electrical switch means are indicated at 41 and may be understood to be operatively connected in the compressor discharge, just downstream of the compressor discharge ports, to sense air discharge pressure.
  • the control circuit for the prior art, rotary compressor control system of FIG. I is depicted in FIG. 2 and may be seen to include normally closed contacts 42 of the pressure switch PS-A, the operating solenoid 44 of the three-way solenoid valve 28, and suitable motor starter interlock means 46, to break current to the solenoid on shutdown to bleed the unit which are respectively connected as shown in series across the line sources 52 and 54 by leads 48 and 50.
  • the normally closed contacts 58 and 60 of suitable, motor overload responsive safety devices are connectable in series across the line sources 52 and 54 by leads 74 and 76 and the switch pole 68 when the selector switch 72 is in the constant speed position thereof.
  • the start-stop contact 78 of the two-position selector switch 72, and the remaining normally close contacts 80 of the pressure switch PS-A are connected as shown in series by lead 82 which is in turn connectable in series with leads 48 and 74 across the said line sources through the switch pole 68 when the selector switch 72 is in the start-stop position thereof.
  • the three-way solenoid valve 28 is arranged in the flow diagram of FIG. 1 to connect conduits 30 and 32 when the valveoperatingsolenoid 44 is deenergized and it may be understood that this will be effective to supply a pressure signal from the air storage tank 20 to the suction control means 12 to close the latter and unload the rotary compressor 10, and to concomitantly supply a pressure signal therefrom to the oil air tank bleeddown valve 34 to connect conduit 36 with the bleeddown valve port 40 to bleeddown the oil air tank 16.
  • valve-operating solenoid 44 of valve 28 With the valve-operating solenoid 44 of valve 28 energized, it may be understood that the three-way solenoid valve 28 will be elTective to vent conduit 32, and accordingly conduit 38, to atmosphere through vent port 33 with the results that the compressor suction control will reopen to reload the compressor, while the oil air tank bleeddown valve 34 terminates the bleeddown of the oil air tank 16 through conduit 36.
  • pressure switch PS-A will be set to open switch contacts 42 and 80 in response to a predetermined pressure in air storage tank 20.
  • the motor starter 64 will be deenergized through the opening of switch contacts 80 in lead 82 to stop the compressor 10.
  • the opening of switch contacts 42 in lead 50 will effect the deenergization of the valve-operating solenoid 44 whereby the solenoid valve 28 will operate the suction control 12 to unload the compressor while commencing the bleeddown of the oil air tank 16 to atmosphere through bleeddown valve port 40.
  • control system being effective to immediately restart the compressor 10 every time the pressure in air storage tank 20 falls below a predetermined minimum pressure, excessive restarting of the compressor motor with attendant damage thereto and/or decrease in the operational life thereof, will most probably result.
  • the oil air tank 16 is enabled to bleeddown to atmosphere, there being substantially no flow of air through the compressor 10 when the latter operates unloaded, it may be understood that the pressure therein will become insufficient to immediately supply adequate lubrication to the compressor 10 upon subsequent restarting of the latter, thus giving rise to the possibility of damage to the compressor, from inadequate lubrication resulting from repeated restarting under such conditions.
  • the operational noise level of the compressor 10 is markedly increased, and/or the effect thereof upon operating personnel markedly aggravated, by the bleed of the oil air tank directly to atmosphere through bleeddown valve port 40, and by the change in pitch of the operational noise of the compressor 10 as the latter cycles between loaded and unloaded operation. Too, the substantial lack of airflow through the compressor 10 during unloaded operation thereof will materially decrease the effectiveness of the temperature sensing switch means 41 under such conditions, as should be obvious.
  • the setting of the selector switch 72 to the constant speed position thereof will prevent excessive compressor motor restarting against high compressor discharge system pressure loads, it will not compensate for the other significant disadvantages enumerated above, and further, will require increased electrical power since the compressor motor will be operating constantly.
  • the rotary compressor 90 comprises compressor suction control means 92, including a closure disc 94, which is actuable in conventional manner by a plunger rod 96 to load and unload the said compressor.
  • the suction control means 92 comprise a compressor air inlet conduit 98 connected thereto, and suitable air filter means 100 are connected therein as shown for obvious purpose.
  • a discharge conduit 102 connects the discharge of the rotary compressor 90 to operatively associated oil air tank and demister means104 and 106, respectively, and a temperature sensitive switch as indicated at 108 is disposed as shown at the compressor discharge just downstream of the compressor discharge ports to sense the temperature of the compressed air discharged therefrom.
  • An air storage tank is indicated at 110, and a conduit 112, including a check valve 114 connected therein as indicated, connects the demister 106 to the said air storage tank.
  • a double contact, normally closed pressure switch is indicated as PS-B and is connected as shown by conduit 116 to the air storage tank 110 so as to be responsive to the pressure in the latter.
  • a three-way solenoid valve is indicated at 118 and is connected to the air storage tank 110 by conduit 120, and to the suction control means 92 by conduit 122.
  • the three-way solenoid valve 118 includes a venting port as indicated at 124 to vent the same to atmosphere.
  • An oil air tank bleeddown valve is indicated at 126 as is connected to the demister 106 by conduit 128, and to the conduit 122 by a conduit 130.
  • a bleed conduit 132 comprising a restriction as indicated at 133 interposed therein, extends as shown from the oil air tank bleeddown valve 126 into communication with the suction control means 92 at a location in the latter upstream of the closure disc 94, whereby is believed made clear that the said bleed conduit extends into communication with the atmosphere through the air inlet filter means 100.
  • An air injection conduit 134 extends as shown from the oil air tank bleeddown valve 126 into communication with the suction control means 92 but at a location in the latter downstream of the closure disc 96, whereby is believed made clear that the said air injection conduit extends into communication with the inlet ports of the rotary compressor 90.
  • a check valve 136 is interposed as shown in the air injection line 134 to prevent flow therethrough in the direction of the said bleeddown valve.
  • a normally open pressure responsive switch is indicated at PS-C and is connected by conduit 138 to the oil air tank 104 so as to be responsive to the pressure in the latter,
  • the control circuit for the rotary compressor control system of FIG. 3 is depicted in FIG. 4 and may be seen to include normally closed contacts 140 of the pressure switch PS-B, the valve-operating solenoid 142 of the three-way solenoid valve 118, and suitable motor starter interlock means 144, to break current to the solenoid on shutdown to bleed the unit respectively connected as shown in series across the line sources 150 and 152 by leads-146 and 148.
  • this control circuit are the normally closed contacts 154 and 156 of suitable, motor overload safety devices, the normally closed contacts 158 of the-temperature responsive switch means 108, the compressor motor starter means 160, and the pole 162 and constant speed contact 164 of a two-position selector switch 166, respectively, all of which are connectable in series across the said line sources by leads 168 and 170, and the switch pole 162, when. the selector switch 166 is in the constant speed position thereof.
  • the remaining normally closed contacts 172 of the normally closed pressure switch PS-B, and the start-stop contact 174 of the selector switch 166 are connected in series as shown by lead 176, and the normally closed contacts 178 of the normally closed pressure switch PS-C are connected as shown in parallel with normally closed contacts 172 by lead 180.
  • the paralleLconnected contacts 172 and 178 may be connected in series with the motor starter 160 and the respective contacts 158, 156 and 154, respectively, across the line sources 152 and 150 through leads 146, 180, 176, the selector switch pole 162 and lead 170 when the selector switch 166 is in the start-stop position thereof.
  • the three-way solenoid valve 118 is arranged in the flow diagram of FIG. 3 to connect conduits 120 and 122 when the valve-operating solenoid 142 is deenergized to supply a pressure signal from the air storage tank to the suction control means 92 to close the closure disc 94 and unload the compressor 90.
  • deenergization of the valve-operating solenoid 142 will result in the said valve connecting conduits and supplying a pressure signal to the oil air tank bleeddown valve 126 to open the latter to connect conduit 128 with each of restricted bleed conduit 132 and air injection conduit 134, it being noted that the conduits 132 and 134 are preferably connected to the same bleeddown valve port to simplify the latter.
  • valve-operating solenoid 142 Conversely, with the valve-operating solenoid 142 energized, three-way solenoid valve 118 is arranged to vent conduit I22, and accordingly conduit 130, to atmosphere through vent port 124 with the result that the compressor suction control means 92 will reopen to reload the compressor 90, while the bleeddown of the oil air tank 104 through restricted bleed conduit 132 is terminated by the closure of bleeddown valve 126.
  • pressure switch PS-B would be set to open the respective normally closed contacts and 172 thereof when the pressure in air storage tank 110 assumed a predetermined maximum in the order, for example, of l15l20 p.s.i., and to reclose the said contacts when the said pressure assumed a predetermined minimum in the same range but somewhat lower than said predetermined maximum.
  • pressure switch PS-C would be set to close the normally open contacts 178 thereof when the pressure in the oil air tank exceeded a predetermined'minimum in the order, for example, of 2025 p.s.i., and to reclose the said contacts when the said pressure returned to the said predetermined minumum.
  • restriction 133 in bleed conduit 132 would be sized to provide a bleeddown time of approximately 2 to 3 minutes for the bleeddown of the oil air tank from the 115-120 p.s.i. range to the 2025 p.s.i. range.
  • the pressure signal to the suction control means 92 will function to unload the compressor 90 through closure of the closure disc 94, while the pressure signal to bleeddown valve 126 will function to commence the bleeddown of air from the oil air tank through restricted bleed conduit 132 to atmosphere through the suction control means 92 and the air inlet filter means 100, and will function to commence the injection of air form the said oil air tank through injection conduit 134 into the compressor inlet ports downstream of the now closed closure disc 94.
  • Unloaded operation of the compressor 90 will continue for the period of time discussed above until the pressure in oil air tank 164 is bled down to the predetermined minimum, also as discussed above, whereupon the ciosed contacts 178 of the pressure responsive switch PS-C will open to deenergize the motor starter 160 and discontinue operation of the compressor 90. Accordingly is believed made clear that the provision of pressure switch PS-C, and the connection of the closed contacts 178 thereof in parallel with normally open contacts 172 of PS-B will positively prevent stopping of the compressor motor until the oil air tank 104 has been bied down to the said predetermined minumum pressure to thus positively prevent the compressor motor from having to restart the compressor 90 against a high-pressure load with resultant possibility of compressor blade damage and high initial torque and electrical power demand as discussed hereinabove.
  • control system will remain as described until the pressure in the air storage tank 110 falls below said predetermined minimum, at which time the contacts 172 and 140 of PS-B will reclose to respectively reenergize the motor starter means 16-0 to restart the compressor 90, and coneomitantly reenergize the valve-operating solenoid 142 to terminate the supply of pressure signals to the suction control means 92 and the bleeddown valve 126 with the results that the compressor 90 will be reloaded and the bleeddown and injection of air through conduits 132 and 134 terminated.
  • FIGS. 5, 6 and 7 it may be understood that the same is substantially identical to that depicted in FIGS. 3 and 4 whereby like reference numerals are utilized to identify like system components of the former.
  • a controlled restriction bleeddown valve 190 which, as illustrated in cross section in FIG. 6, comprises an outer valve body 192 having a stepped port 194 extending therethrough.
  • An inner valve body 196 is slidably disposed as shown in the port 194 and biased toward the inlet end 198 of the latter by a compression spring 200.
  • a restricted valve port 202 is formed to extend as shown through the inner valve body 196.
  • the controlled restriction bleeddown valve 190 will return to the position thereof of FIG. 6 whereby the passage of air therethrough can occur only through restricted valve port 202.
  • controlled restriction bleeddown valve 19 it may be understood that rapid oil air tank bleeddown to a low compressor power consumption level may be achieved, followed by controlled oil air tank bleeddown through restricted valve port 202 to establish the predetermined oil air tank bleeddown time as discussed hereinabove.
  • conduits 116 and would be suitably connected in compressor discharge means in the nature of conduit 112 so as to insure that pressure switch PS-B would remain effective to accurately sense compressor discharge pressure, while conduit 120 would remain efiective to supply the requisite pressure signals for application through the three-way solenoid valve 118 as described.
  • a compressor control system for use with a motor driven compressor including compressor suction control means which are operable to load and unload said compressor, oil air tank means connected to the compressor discharge, air storage tank means connected to the discharge of said oil air tank means, and control means operatively associated with said air storage tank means and said compressor motor, and operable to respectively operate said suction control means to unload said compressor, and to start and stop operation of said compressor motor, in response to the pressure said air storage tank means; the improvements comprising, bleeddown means operatively associated with said oil air tank means and operable in response to compressor-unioading operation of said control means to bleeddown said oil air tank means at a predetermined rate, and means operatively associated with said oil air tank means and said compressor motor, respectively, and responsive to the pressure in the former to prevent stopping of said compressor motor by said control means until the pressure in said oil air tank means has been bled down to a predetermined level, whereby immediate restarting of said compressor against a high high-pressure in said oil air tank is prevented.
  • bleeddown means comprise a restricted conduit in fluid flow communication with said oil air tank means.
  • bleeddown means comprise a restricted conduit in fluid flow communication with said oil air tank means.
  • bleeddown means are effective to bleeddown said oil air tank through said compressor suction control means tosubstantially attenuate the noise attendant oil air tank bleeddown.
  • bleeddown means are effective to bleeddown said oil air tank through said compressor suction control means to substantially attenuate the noise attendant oil air tank bleeddown.
  • bleeddown means comprise a restricted conduit in fluid flow communication with said oil air tank means.
  • said bleeddown means comprise variable rate bleeddown means which are operable to bleeddown said oil air tank at varying rates in accordance with the pressure in the latter.
  • said bleeddown means comprise variable rate bleeddown means which are operable to bleeddown said oil air tank at varying rates in accordance with the pressure in the latter.
  • said bleeddown means comprise variable rate bleeddown means which are operable to bleeddown said oil air tank at varying rates in accordance with the pressure in the latter.
  • said bleeddown means comprise variable rate bleeddown means which are operable to bleeddown said oil air tank at varying rates in accordance with the pressure in the latter.
  • variable rate bleeddown means comprise a controlled restriction bleeddown valve in the fluid flow communication with said oil air tank means, said valve including an outer valve body and an inner valve body having first and second relative positions, said valve being operable to bleeddown said oil air tank at a different rate when said valve bodies are in said first relative positions than when the same are in said second relative positions.
  • variable rate bleeddown means comprise a controlled restriction bleeddown valve in the fluid flow communication with said oil air tank means, said valve including an outer valve body and an inner valve body having first and second relative positions, said valve being operable to bleeddown said oil air tank at a different rate when said valve bodies are in said first relative positions than when the same are in said second relative positions.
  • said control means comprise first pressure switch means having normally closed contacts and being responsive to the pressure in said air storage tank to open said contacts only when said pressure assumes a predetermined level
  • said means operatively associated with said oil air tank means comprise second pressure switch means having normally closed contacts and being operable to open the same only when the pressure in said oil air tank means assumes a predetermined level
  • series connected energization circuit means for said compressor motor and means connecting said first and second pressure switch means contacts in parallel in said series connected energization circuit means whereby, energization of said compressor motor will be continued albeit the opening of said first pressure switch means contacts until the opening of said second pressure switch means contacts.
  • said control means comprise first pressure switch means having normally closed contacts and being responsive to the pressure in said air storage tank to open said contacts only when said pressure assumes a predetermined level
  • said means operatively associated with said oil air tank means comprise second pressure switch means having normally closed contacts and being operable to open the same only when the pressure in said oil air tank means assumes a predetermined level
  • series connected energization circuit means for said compressor motor and means connecting said first and second pressure switch means contacts in parallel in said series connected energization circuit means
  • said control means comprise first pressure switch means having normally closed contacts and being responsive to the pressure in said air storage tank to open said contacts only when said pressure assumes a predetermined level
  • said means operatively associated with said oil air tank means comprise second pressure switch means having normally closed contacts and being operable to open the same only when the pressure in said oil air tank means assumes a predetermined level, series connected energization circuit means for said compressor motor, and means connecting
  • control means comprise first pressure switch means having normally closed contacts and being responsive to the pressure in said air storage tank to open said contacts only when said pressure assumes a predetermined level
  • said means operatively associated with said oil air tank means comprise second pressure switch means having normally closed contacts and being operable to open the same only when the pressure in said oil air tank means assumes a predetermined level
  • series connected energization circuit means for said compressor motor and means connecting said first and second pressure switch means contacts in parallel in said series connected energization circuit means whereby, energization of said compressor motor will be continued albeit the opening of said first pressure switch means contacts until the opening of said second pressure switch means contacts.
  • a compressor control system for use with a motor driven compressor including compressor inlet suction control means which are operable to load and unload said compressor, oil air tank means connected to the compressor discharge, air storage tank means connected to the discharge of said oil air tank means, and control means operatively associated with said air storage tank means and said compressor motor, and operable to respectively operate said suction control means to unload said compressor, and to start and stop operation of said compressor motor, in response to the pressure in said air storage tank means; the improvements comprising, air injection means operatively associated with said oil air tank means and operable in response to compressor unloading operation of said control means to inject air from said oil air tank means into the inlet of said compressor downstream of the suction control means during initial unloaded operation thereof to prevent sudden changes of operational load on the compressor.
  • said bleeddown means are effective to bleeddown said oil air tank through said compressor suction control means to substantially attenuate the noise attendant oil air tank bleeddown.
  • a compressor assembly comprising:
  • a compressor having an inlet and an outlet
  • a motor operatively associated with said compressor to drive said compressor
  • conduit means connected to said outlet of said compressor to carry the discharge of said compressor
  • control means operatively associated with said compressor discharge conduit means and said motor to actuate said compressor unloading means and to start and stop said motor in response to the pressure in said compressor discharge conduit means;
  • bleeddown means operatively communicated with said compressor discharge conduit means and the compressor inlet and actuated by said compressor unloading means to inject a portion of the compressor discharge into the inlet and through the compressor while bleeding down said compressor discharge conduit means at a predetermined rate;
  • control means including means to continue operation of said motor until the pressure in said compressor discharge conduit means has been bled down below a predetermined value, so that immediate restarting of said compressor against a high-pressure load in said compressor discharge conduit means is prevented.
  • a compressor assembly comprising:
  • a compressor having an inlet and an outlet
  • a motor operatively associated with said compressor to drive said compressor
  • receiving means connected to said outlet of said compressor to receive the discharge of said compressor
  • control means operatively associated with said compressor discharge receiving means and said motor to actuate said compressor unloading means and to start and stop said motor in response to the pressure in said compressor discharge receiving means;
  • bleeddown means communicating with said compressor discharge receiving means and actuated by said compressor unloading means to bleeddown said compressor discharge receiving means at a predetermined rate
  • injecting means connected with the compressor discharge receiving means and the compressor inlet for injecting a limited portion of the compressor discharge into the compressor during bleeddown;
  • control means including means to delay stopping of the compressor motor after unloading of the compressor to prevent immediate restarting of the motor against high pressure in the compressor discharge receiving means.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Control Of Positive-Displacement Pumps (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)
US819011A 1969-04-24 1969-04-24 Rotary compressor control system Expired - Lifetime US3582233A (en)

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US81901169A 1969-04-24 1969-04-24

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US (1) US3582233A (enrdf_load_stackoverflow)
DE (1) DE2018939A1 (enrdf_load_stackoverflow)
FR (1) FR2046434A5 (enrdf_load_stackoverflow)
GB (1) GB1270087A (enrdf_load_stackoverflow)

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3788776A (en) * 1972-08-10 1974-01-29 Gardner Denver Co Compressor unloading control
US3824040A (en) * 1972-04-06 1974-07-16 Compump Syst Inc Floatless control of liquid level, especially useful in atomizing systems
US3860364A (en) * 1971-07-09 1975-01-14 Compump System Inc Pump-compressor system
US3873239A (en) * 1971-10-22 1975-03-25 Arthur A Jamieson Compressor control
US4063855A (en) * 1976-05-03 1977-12-20 Fuller Company Compressor capacity and lubrication control system
US4086041A (en) * 1975-08-05 1978-04-25 Diesel Kiki Co., Ltd. Rotary compressor comprising improved rotor lubrication system
US4453893A (en) * 1982-04-14 1984-06-12 Hutmaker Marlin L Drainage control for compressed air system
US5009576A (en) * 1990-01-08 1991-04-23 Ingersoll-Rand Company Compressor unloader controller
US5368019A (en) * 1992-12-16 1994-11-29 Puritan-Bennett Corporation System and method for operating a respirator compressor system under low voltage conditions
US5667367A (en) * 1994-04-08 1997-09-16 Kabushiki Kaisha Kobe Seiko Sho Air compressor
US6474950B1 (en) 2000-07-13 2002-11-05 Ingersoll-Rand Company Oil free dry screw compressor including variable speed drive
US20030039557A1 (en) * 2001-08-27 2003-02-27 The Coleman Company, Inc. Air compressor workbench
US20080050250A1 (en) * 2006-08-25 2008-02-28 Haldex Brake Corporation Air supply system with reduced oil passing in compressor
US20220136513A1 (en) * 2019-04-15 2022-05-05 Hitachi Industrial Equipment Systems Co., Ltd. Gas compressor

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT378041B (de) * 1983-01-13 1985-06-10 Hoerbiger Ventilwerke Ag Einrichtung zum steuern von schraubenverdichtern
AT392485B (de) * 1985-05-21 1991-04-10 Boehler Gmbh Werkstoff zur herstellung von stanz- und gegenplatten

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2234488A (en) * 1939-11-08 1941-03-11 Wagner Electric Corp Compressor unloading valve mechanism
US2345797A (en) * 1943-03-27 1944-04-04 Ingersoll Rand Co Compressor system
US3072320A (en) * 1960-10-05 1963-01-08 Chicago Pneumatic Tool Co Rotary fluid compressor
US3186631A (en) * 1963-10-03 1965-06-01 Jaeger Machine Co Rotary compressor
US3260444A (en) * 1964-03-30 1966-07-12 Gardner Denver Co Compressor control system
US3349994A (en) * 1965-12-10 1967-10-31 Worthington Corp Unloading system for rotary compressor
US3448916A (en) * 1967-06-16 1969-06-10 Ingersoll Rand Co Unloading system for compressors

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2234488A (en) * 1939-11-08 1941-03-11 Wagner Electric Corp Compressor unloading valve mechanism
US2345797A (en) * 1943-03-27 1944-04-04 Ingersoll Rand Co Compressor system
US3072320A (en) * 1960-10-05 1963-01-08 Chicago Pneumatic Tool Co Rotary fluid compressor
US3186631A (en) * 1963-10-03 1965-06-01 Jaeger Machine Co Rotary compressor
US3260444A (en) * 1964-03-30 1966-07-12 Gardner Denver Co Compressor control system
US3349994A (en) * 1965-12-10 1967-10-31 Worthington Corp Unloading system for rotary compressor
US3448916A (en) * 1967-06-16 1969-06-10 Ingersoll Rand Co Unloading system for compressors

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3860364A (en) * 1971-07-09 1975-01-14 Compump System Inc Pump-compressor system
US3873239A (en) * 1971-10-22 1975-03-25 Arthur A Jamieson Compressor control
US3824040A (en) * 1972-04-06 1974-07-16 Compump Syst Inc Floatless control of liquid level, especially useful in atomizing systems
US3788776A (en) * 1972-08-10 1974-01-29 Gardner Denver Co Compressor unloading control
US4086041A (en) * 1975-08-05 1978-04-25 Diesel Kiki Co., Ltd. Rotary compressor comprising improved rotor lubrication system
US4063855A (en) * 1976-05-03 1977-12-20 Fuller Company Compressor capacity and lubrication control system
US4453893A (en) * 1982-04-14 1984-06-12 Hutmaker Marlin L Drainage control for compressed air system
US5009576A (en) * 1990-01-08 1991-04-23 Ingersoll-Rand Company Compressor unloader controller
US5368019A (en) * 1992-12-16 1994-11-29 Puritan-Bennett Corporation System and method for operating a respirator compressor system under low voltage conditions
US5667367A (en) * 1994-04-08 1997-09-16 Kabushiki Kaisha Kobe Seiko Sho Air compressor
US6474950B1 (en) 2000-07-13 2002-11-05 Ingersoll-Rand Company Oil free dry screw compressor including variable speed drive
US20030039557A1 (en) * 2001-08-27 2003-02-27 The Coleman Company, Inc. Air compressor workbench
US6773237B2 (en) * 2001-08-27 2004-08-10 Coleman Powermate, Inc. Air compressor workbench
US20080050250A1 (en) * 2006-08-25 2008-02-28 Haldex Brake Corporation Air supply system with reduced oil passing in compressor
US20220136513A1 (en) * 2019-04-15 2022-05-05 Hitachi Industrial Equipment Systems Co., Ltd. Gas compressor
US11994138B2 (en) * 2019-04-15 2024-05-28 Hitachi Industrial Equipment Systems Co., Ltd. Gas compressor with a plurality of air realease systems each having an air release valve and an air regulating valve

Also Published As

Publication number Publication date
DE2018939A1 (de) 1971-03-18
GB1270087A (en) 1972-04-12
FR2046434A5 (enrdf_load_stackoverflow) 1971-03-05

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