US2420098A - Compressor - Google Patents

Description

May 6, 1947. w. J. ROULEAU 2,420,098

l COMPRESSOR Filed Dec.` 7. V1944 Patented May 6, 1947 UNITED STATES PATENT OFFICE COMPRESSOR Wilfred J. Rouleau, Quincy, Mass.

Application December 7, 1944, Serial No. 566,984

6 Claims.

This invention relates to compressors for compressing air and other gas and particularly to the means for cooling the air as it is compressed thereby to absorb the heat of compression.

One common method employed for thus cooling the air is to spray water into the cylinder during the operation of the compressor, and a pump is usually used for this purpose.

It is an object of my present invention to provide a simplified but novel construction by which the water or other cooling medium will be automatically sprayed into the cylinder without the use of any pump so long as the pressure in the vcylinder is less than the maximum pressure developed by the compressor, said spraying operation ceasing as soon as the maximum pressure within the cylinder has been reached.

In order to give an understanding of the invention, I have illustrated in the drawings a selected embodiment thereof which will now be described after which the novel features will be pointed out in the appended claims.

In the drawings:

Fig. 1 is a view partly in section of a compressor embodying my invention.

Fig. 2 is a fragmentary view, also partly in section, showing the shutoff and vent valve for the tank containing the cooling medium.

In the drawings I indicates generally a compressor of any suitable or known construction, said compressor being provided with theusual cylinder 2 in which operates the piston 3. The compressor herein shown is of the double acting type, although the invention is equally applicable to a compressor of the single acting type. The compressor is shown as having the usual intake chamber 4 which is supplied with gases to be compressed through the intake pipe 5, said chamber d communicating with the cylinder through the medium of the usual inlet valves 6. The compressor is also provided with the usual discharge chamber 'I which communicates with the ends of the cylinder through discharge valves 8, and said chamber 'I is connected by a discharge pipe B to a storage tank III in which the air or other gas to be compressed is stored. Said tank III has a discharge pipe II through which the compressed gases may be withdrawn and it also is provided with the usual drain pipe I2. The parte thus far described are such as are commonly found in compressors of this type.

Each cylinder head of thecylinder 2 is provided with a spray nozzle I3 through which water or other cooling medium may be sprayed into the cylinder. These nozzles I3 are ,suppliedl with the cooling medium through a supply pipe I4 which is provided with two branches I5 and I6, one leading to one ofthe nozzles I3 and the other leading to the other nozzle I3. The supply pipe I4 is illustrated as having a check valve I1 therein and also a shutoff valve I8.

In accordance with my present invention I provide a tank -IS which contains the water or other cooling medium 2B and to which the supply pipe I4 is connected. The tank I9 is connected to the storage tank Ill so that thecooling medium 20 in the tank I9 is subjected to the same pressure as that in the storage tank.

For this purpose the upper end of the tank I9 is connected by a pipe 2l to the storage tank and as will be obvious by this means the cooling medium in thetank 20 is continuously subjected to the pressure in the storage tank Il). With this construction and so long as the shutoii valve IB in the pipe I4 is open, the pressure to which thecooling medium 20 in the tank I9 is subjected will force cooling medium through each nozzle I3 so long as the pressure in the corresponding end of the cylinder chamber is less than the pressure in the storage tank I0. When, however, during the compression stroke the pressure in thecylinder 2 has reached its maximum and the corresponding-discharge valve 8 opens to permit discharge of the compressed gas, the delivery of a spray of water from the nozzle I3 will cease because of the fact that the pressure at the discharge end of the nozzle has been equalized with that on the cooling medium in the tank I9.

The piston 3 in Fig. 1 is shown as at the left hand end of its stroke, and during its movement toward the left, which is its suction stroke for the right hand end of the cylinder, the pressure in the cylinder will be less than that in the storage tank, and therefore less than that to which the cooling medium Z' in the tank I9 is subjected, and therefore, the cooling medium will be automatically sprayed into the cylinder as shown in Fig. 1. During the movement of the piston 3 to the right, the air or gas in the cylinder will be compressed until nally the pressure in the cylinder is equal to that in the storage tank at which time the discharge valve 8 will open and the compressed gas will be forced from the cylinder into the storage tank. As soon as the pressure in the cylinder has been built up so as to equalize that in the Storage tank, further delivery of cooling medium through the nozzle I3 will cease and the cooling medium will `only' again be delivered from the 3 nozzle I3 when the piston begins its suction stroke.

With this construction the use of any pump or other similar machinery for forcing the cooling medium through the spray nozzles is entirely eliminated, and thereby the construction and operation of the cooling means for the compressor is much simplied.

I propose to incorporate in the pipe 2Ila threeway valve 22 by which the communication Vbetween the storage tank II] and the tank I9 may be closed and the tank I9 may be vented through avent pipe 23. 24 indicates a supply pipe through which added cooling water or other cooling medium may be supplied to the tank I9 when necessary. This pipe 24 has a check valve 25 therein to prevent any back flow through vthe pipe 24.

The tank I9 is also shown as beingequipped with a gauge 25 by which the level of the cooling Vmedium V2) therein may be observed.

When the cooling medium in the tank I9 is nearexhaustion, then thevalve 22 is turned into the position shown in Fig. 2, ,thereby cutting off `commur,iication between the ,storage tank I and the tank I9 and opening said tank to the atmosphere 4through ,the vent ,pipe 23. Water or other cooling medium ,will then be supplied lto the tank 4through the supply pipe 24 Aand when the tank ,is nlled, the valve v`2.2 Yis again moved into position to cut off the vent .but to open communication between it andthe storage tank Ill.

The spraying of water into the cylinder of the .compressor has a tendency7 to wash out of the cylinder the lubricant necessary to properly lubricate the piston. Inorder to prevent such loss 4o f lubricant, I propose to supply a suitable 1ubricating liquid to the pipe I4 so that said 1ubricating liquid will mingle with the cooling medium and thus 'be delivered to the cylinder with the spray. For this purpose, there is shown a ylubricantVsupplying pipe 21 which is connected into the pipe connection I4. Any suitable liquid lubricant may be supplied to the pipe 2'I. One lubricant which is suitable for this purpose is colloidal graphite which is known by the trade name Aguadag By this lmeans a sufcient amount of lubricant for properly lubricating the piston Ais being constantly fed to the cylinder, thereby .avoiding any possibility of insulcient lubrication due to the presence of the spray.

While the shutoi valve I8 may be operated in any suitable way whenever it is desired to close or open the communication between the tank I9 and the nozzles I 3, yet I have herein illustrated means for operating said valve in conjunction Vwith the control switch by which the motor for the compressor is started and stopped, so that when the motor circuit is opened and the compressor ceases to operate, the valve I8 Will be automatically closed, thus shutting off the supply of cooling medium to the nozzles, while when the switch is operated to close the motor circuit andrstart up the compressor, the valve I8 will be open so as to permit delivery of cooling medium Ato the nozzles.

I have shown I nore or less diagrammatically at 2,3. a knife switch of any usual construction for opening and closing the circuit of the motor by which the compressor is operated, such switch including the twocontacts 29 and theknife contact 30 which is pivoted at 3| and which can be turned about its pivot to open and close the switch. The swingingcontact 30 has rigid therewith anarm 32 which is connected by a link 33 -by closing the shutoff valve I8. With this construction, the delivery of cooling medium to the nozzles is automatically terminated when the compressor is shut down, and delivery is automatically re-established when the switch is closed to start up the compressor.

If desired, the three-way valve 22 may be operated automatically by means of a float that in turn is controlled by the level of the cooling 4medium inthe tank I9. Inasmuch as floats for opening and closing a valve are used in a number of diierent arts, -I have not thought it necessary to illustrate the oat herein.

I claim:

-1. A compressor for compressing air and other gases comprising a cylinder, a piston operating therein, a spray nozzle to deliver cooling medium to the cylinder, a tank containing the cooling medium, means connecting the tank to the nozzle, and means for maintaining in the tank a pressure substantially equal to the maximum pressure developed by the compressor, whereby cooling medium will be automatically delivered from the nozzle into the cylinder of the compres- -sor except when the pressure in said cylinder equals or exceeds that in the tank.

2. A'compressor for compressing air and other gases comprising a cylinder, a piston operating therein, a spray nozzle to deliver cooling medium `to the cylinder, 'a storage tank to receive the gases compressed by the compressor, a second tank containing the cooling'medium, means connecting said second tank to the nozzle, and means connecting said second tank to the storage tank whereby the cooling medium in the second tank will be consequently subjected to the pressure in the storage tank and will thus be constantly forced through the nozzle into the cylinder except when the maximum pressure has been developed in said cylinder,

3. A compressor for compressing air and other gases comprising a cylinder, a piston operating therein, a spray nozzle to deliver cooling medium to the cylinder, a tank containing the cooling medium, means connecting the tank to the nozzle, means for maintaining in the tank a pressure substantially equal to the maximum pressure developed by the compressor, whereby cooling medium will be automatically delivered from the nozzle into the cylinder of the compressor except when the pressure in said cylinder equals or exceeds that in the tank, and means for delivering a lubricant to the cooling medium prior to its delivery from the nozzle.

4. A compressor for compressing air and other gases comprising a cylinder, a piston operating cept when the pressure in said cylinder equals or exceeds that in the tank, and means for automatically closing the communication between the tank and the nozzle when the compressor ceases operation.

5. A compressor for compressing air and other gases comprising a cylinder, a piston operating therein, a spray nozzle to deliver cooling medium to the cylinder, a tank containing the cooling medium, means connecting the tank to the nozzle, means for continuously subjecting the cooling medium in the tank to the maximum pressure developed by the compressor, whereby cooling medium will be automatically delivered from the nozzle into the cylinder of the compressor except when the pressure in said cylinder equals or exceeds that in the tank, and means for automatically closing the communication between the tank and the nozzle when the compressor ceases operation and for automatically opening said communication when the compressor is started in operation,

6. A compressor for compressing air and other gases comprising a cylinder, a piston operating therein, a spray nozzle to deliver cooling medium to the cylinder, a tank containing the cooling REFERENCES CITED The following references are of record in the file of this` patent:

UNITED STATES PATENTS Number Name Date 224,081 Eckart Feb. 3, 1880 233,432 Pitchford Oct. 19, 1880 268,348 Wood et al. Nov. 28, 1882 294,299 Ostergren Feb. 25, 1902 2,042,991 Harris June 2, 1936

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