Rotary compressor control system

Claim 2

In 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 in said air storage tank means; the improvements comprising, bleeddown means operatively associated with said oil air tank means and operable in response to compressor-unloading 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.

Claim 3

In a compressor control system as in claim 1; said improvements further 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 suction of said compressor during unloaded operation thereof to maintain a flow of air therethrough to prevent bleeddown of said oil air tank to atmospheric pressure to insure adequate compressor lubrication.

Claim 4

In a compressor control system as in claim 1 wherein said bleeddown means comprise a restricted conduit in fluid flow communication with said oil air tank means.

Claim 5

In a compressor control system as in claim 2 wherein said bleeddown means comprise a restricted conduit in fluid flow communication with said oil air tank means.

Claim 6

In a compressor control system as in claim 1 wherein 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.

Claim 7

In a compressor control system as in claim 2 wherein 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.

Claim 8

In a compressor control system as in claim 6 wherein said bleeddown means comprise a restricted conduit in fluid flow communication with said oil air tank means.

Claim 9

In a compressor control system as in claim 1 wherein, 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.

Claim 10

In a compRessor control system as in claim 2 wherein, 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.

Claim 11

In a compressor control system as in claim 5 wherein, 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.

Claim 12

In a compressor control system as in claim 6 wherein, 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.

Claim 13

In a compressor control system as in claim 8 wherein, said 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.

Claim 14

In a compressor control system as in claim 10 wherein, said 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.

Claim 15

In a compressor control system as in claim 1 wherein, 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.

Claim 16

In a compressor control system as in claim 2 wherein, 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.

Claim 17

In a compressor control system as in claim 5 wherein, 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.

Claim 18

In a compressor control system as in claim 8 wherein, 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.

Claim 19

In 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.

Claim 20

In 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.

Claim 21

In a compressor control system as in claim 18; said improvements further comprising, bleeddown means operatively associated with said oil air tank means and operable in response to compressor-unloading operation of said control means to bleeddown said oil air tank means at a predetermined rate.

Claim 22

In a compressor control system as in claim 19 wherein; 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.

Claim 23

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; means to unload said compressor by throttling the inlet thereof, operatively associated with the inlet 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; said 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.

Claim 24

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; means to unload said compressor by throttling the inlet thereof, operatively associated with the inlet 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; said 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.

Claim 25

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; means operatively associated with the inlet of said compressor to unload said compressor by throttling the inlet thereof; 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; and 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; said 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.

Claim 26

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; means operatively associated with the inlet of said compressor to unload said compressor by throttling the inlet thereof; 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; and 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; said 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.