US2054640A

US2054640A - Inlet unloader

Info

Publication number: US2054640A
Application number: US27285A
Authority: US
Inventors: August M Stenger
Original assignee: Ingersoll Rand Co
Current assignee: Ingersoll Rand Co
Priority date: 1935-06-19
Filing date: 1935-06-19
Publication date: 1936-09-15
Anticipated expiration: 1953-09-15

Description

Sept. 15, 1936. STENGER 2,054,640

INLET UNLOADER Filed June 19,- 1935 u 817/ ft- BY 2 mi.

HIS ATTORNEY.

Patented Sept. 15, 1935 UNITED STATES PATENT OFFICE to Ingersoll-Rand Company, Jersey City, N. J a corporation of New Jersey Application June 19, 1935, Serial No. 27,285

2 Claims.

This invention relates to compressors, but more particularly to an inlet unloader adapted to be interposed in the intake conduit of a compressor.

One object of the invention is to unload the 5.,- compressor whenever the storage pressure reaches a certain predetermined value.

Another object is to produce a compact and simplified unloader for compressors which requires only a. few simple parts and which may be cheaply operated and maintained.

Other objects will be in part obvious and in part pointed out hereinafter.

In the accompanying drawing forming a part of this specification and in which similar refer- 15. ence numerals refer to similar parts,.

Figure 1 is an elevation, in section, of an inlet unloader constructed in accordance with the practice of the invention and a compressor to which it is applied, and v 20 Figure 2 is a transverse view taken through Figure 1 on the line 2-2.

Referring more particularly to the drawing, the inlet unloader which is designated, in general, by 20 is shown applied to a compressor 2| of which 25 only so much is shown as will serve to illustrate a practical application of the invention.

The compressor 2l comprises a cylinder 22 containing a piston 23 which may be actuated in any suitable manner for compressing the working sub- 30 stance in the cylinder 22. On the end of the cylinder 22 is a head 24 which serves as a closure for the compression chamber and is recessed to provide an inlet chamber 25 and a discharge chamber 26.

Communication between the inlet chamber 25 and the compression chamber is controlled by a suitable inlet valve 21, and a valve 28 in the head 24 controls communication between the compression chamber and the discharge chamber 26. The

fluid intended to be compressed is conveyed into the inlet chamber 25 by an inlet conduit 29, and

a discharge conduit 30 communicating with the chamber 25 conveys the discharge fluid from the compressor to a storage receiver 3|.

45 The inlet unloader 20 constructed in accordance with the practice of the invention and interposed in the intake conduit 29 of the compressor, comprises a casing 32 consisting of a pair of

sections

33 and 34 which may be clamped to- 50 gather in face-to-face relationship, as by bolts 35. The section 33 is recessed to provide a piston chamber 36 of which one end constitutes a pressure chamber 31 which is connected with the receiver 3| by a conduit 38. The piston chamber 55 36 contains a reciprocatory piston 39 having a pressure surface 40 against which pressure fluid may act for actuating the piston 39 in one direction.

The force of the pressure fluid acting against the pressure surface 40 is opposed by a spring 4| 5 arranged in a recess 42 in the piston and acting against the casing section 34. The spring 4| is calibrated to yield at the predetermined maximum pressure which it is intended to maintain in the storage receiver 3|, and the end of the spring 10 projecting from the recess is guided by a stationary plug 43. The plug 43 may be aifixed to the casing section 34 or,-. as shown, may seat upon a packing member 44 clamped between the

casing sections

33 and 34 to prevent leakage of fluid from the casing to the atmosphere.

The inlet conduit 29 or portions thereof which are connected to the unloader are threaded into the casing section 34. One conduit 29 communicates with a passage 45 in the casing section 34 and the packing member 44 and opening directly into the adjacent end of the piston chamber 35, and a passage 46 in the casing section 34 and the packing member 44 affords communication between the piston chamber and the portion of the conduit 29 connecting the unloader with the inlet chamber 25 of the compressor. The arrangement of the

passages

45 and 46 is such that the fluid medium flowing from supply to the compressor passes through the end of the piston chamber 36 so that said piston chamber constitutes, in effect, a portion of the inlet supply line.

The packing member 44 is coextensive with the end surfaces of the casing sections and is substantially of the same conformation as the adjacent surface of the section 34, that is, the passages in the packing member are of substantially the same shape and size as the portions of the

passages

45 and 46 in the casing section 34. They are so located with respect to the wall of the piston chamber and its axis that ample areas of surface of the packing member 44 will lie within the plane of the piston to cooperate with the adjacent end of the piston for efiecting a seal on all sides of the passages and 46. 45

As will, therefore, be readily appreciated, when the piston 39 is seated upon the packing member 44 the

passages

45 and 45 will be thoroughly sealed to prevent leakage of fluid from supply into the compressor and, at the same time, an adequate 50 seal will be maintained around the peripheral edge of the piston 33 to prevent leakage of pressure fluid from the pressure chamber 31 into the compressor or to the source of fluid supply.

Normally, during the operation of the compressor and when the pressure in the storage receiver 3| remains below the value at which the spring 4| is intended to act, the said spring will maintain the piston 39 in the open or raised position to permit free communication between the passages and 46 through the piston chamber, and, therefore, between the compressor and the source of fluid supply. The supply fluid will then flow through the conduit 29, the passage 45, the piston chamber 36, the passage 46 and the portion of the conduit 29 which connects the unloader with the compressor into the inlet chamber 25.

Upon passing through the valve 21 to the compression chamber the fluid is compressed and is discharged through the valve 28, the discharge chamber 26 and the conduit 30 into the storage receiver 3|. This mode of operation continues until the pressure fluid in the storage receiver reaches the value at which the spring 4| yields. The pressure fluid flowing from the storage receiver 3| through the conduit 38 into the pressure chamber 21 will then press the piston 39 against the packing member 44, thus cutting off the further admission of fluid medium from the source to the compressor.

The pressure fluid thus acting against the ac tuating surface 40 presses the piston 39 against the packing member 44 with sufficient force to' prevent leakage of pressure fluid from the piston chamber 36 into the adjacent passages and also to prevent communication between the

passages

45 and 46. The compressor will then be completely unloaded and no further admission of fluid medium into the compressor will take place until the pressure within the storage receiver 3| drops below that exerted by the spring 4!. When this condition prevails in the storage receiver the spring 4| will lift the piston 39 and thereby reestablish communication between the source of fluid medium and the compressor.

I claimi 1. An inlet unloader valve for compressors, comprising a casing consisting of a pair of sections, there being a piston chamber in one section and passages in the other section constituting portions of the inlet passage of the compressor and opening into the piston chamber, a piston in the piston chamber to control communication between the passages and having a pressure surface, means for conveying pressure fluid to the pressure surface to actuate the piston for cutting off communication between the passages, and a packing member clamped between the casing sections cooperating with the piston to prevent leakage of supply fluid through the piston chamber and to prevent leakage of pressure fluid from the piston chamber and the passages along the confronting surfaces of the casing sections to the exterior of the casing.

2. An inlet unloader valve for compressors, comprising a casing consisting of a pair of sections, there being a piston chamber in one section and passages in the other section constituting portions of the inlet passage of the compressor and opening into the piston chamber, a piston in the piston chamber to control communication between the passages and having a pressure surface, means for conveying pressure fluid to the pressure surface to actuate the piston in one direction for cutting off communication between the passages, a spring for actuating the plston to establish communication between the passsages, and a packing member between the sections to prevent leakage of fluid from the casing to the atmosphere and cooperating with the piston to prevent leakage of supply fluid from one passage toanother and to prevent leakage of pressure fluid from the piston chamber to the passages.

AUGUST M. STENGER;