US953617A - Automatic controlling device for fluid-compressors. - Google Patents

Description

E. HERR,

UTO'TG ONTRGLLNG DEVGE FOR FLUID GOPRESSOPS. APELIOATION FILED JUNE 2s, 19708.

VJITNESE INVENTOFI readily lecjuaflises around the piston into inber the springq` 18 holds the control valve l2 in position shown, in which the port 9 is open to chamber l5 the intercooler so'tliat the saine pressure ists aamber i3 baclr oi' the discharge passage l2 which' leads to the same intorcooler or space. Consequently the discharge valve' 8 or the Erst compressor cylinder will operate in its usual manner to control the4 discharge of compressed air to the intercooler il, while the other cylinders -and pistons also operate in the 'usual and well known manner to compress the air to the higher degree of pressure and force the same into the reservoir 8. As soon `the pressure in the reservoir reaches or rises slightly above the predetermined degree for which the spring 28 of my improved device is adjusted, the spring will be slightly compressed by the air pressure in chamber 26V and the stem 29 will open the regulating valve 2l thereby venting air from chamber l? to the atmosphere. By means of the lowering` of pressure on one side ot piston 16, the intercooler pressure acting upon the other side in valve chamber l5 moves the piston and Slide valve 19 against the spring l to a position in which the cavity 20 establishes connection from chamber 13 and port 9 to port 2l and the atmosphere, whereupon the dis charge valve, now having only atmospheric pressure upon its back, rises and is held in its raised and open position seated against its cap by the pressure in passage l2 and the intercooler 4.

As the discharge valve 8 is held in its open position, it will bey seen that no air will be taken into the cylinder of the iirst stage of compression, as the admission valve will not open against the preponderance of pressure in the intercooler between the irst and second stages of compression. lso proportion the clearances in the cylinders 2 and 3 that these cylinders 'will be unloaded simultaneously'` with the unloading of the cylinder l.v l accomplish this by proportioning the clearances in the cylinder 2 so that the cylinder will not draw fluid 'from the receiver 4 except when the cylinder l is worlring yat maximum capacity, and by proportioning the clearances in the cylinder 3 so that it will not draw fluid from the receiver 8 except when the cylinder 2 is dene tiret compressor cylinder as in i operation oli the governor mechanism, the luid in the r ceiver 1; expands, during the operation ci the cylinder l, tlirougli the cylinder and the' receiver and consequently' the pressure in the receiver drops and is only periodically raised to the normal worlring pressure. lt, however, l"the cylinder 2 draws iluid from the receiver at the time or immediately after the cylinder l is unloaded by the loperation or the governor valve, the pressure in the receiver l will not rise to the normal pressure until the cylinder l is again in operation, and the cylinders 2 and 3 will consequently be nnloaded. By unloading, l mean ythat the iiuid coniined in the cylinder will be irst compressed by the cylinders piston and then expanded so as to impart energy to the piston. l may also gradually unload the cylinders 2 and 3 by proportioning the clearances in the cylinder 2 so that the cylinder will receive fluid from the receiver l after the valve 8 is raised and by maintaining the clearances in the cylinder 3 as above described. -`With such an arrangement, the load on the engine will be grad* ually decreased Afrom a maximum to a very low minimum, at which the only work required to operate the compressor will be that necessary to overcome the friction ot the machine. As soon as the cylinder l is unloaded, the pressure in the receiver et starts to drop vand consequently the capacity of the cylinder 2 is reduced proportionately to the drop in pressure. -rlhe reduction in the capacity of the cylinder 2 will cause a. corresponding reduction in the capacity of the cylinder 3. Thecapacities of the cylinders 2 and 3 will decrease until a predetermined pressure is reached in the receiver l, at which the cylinder 2 is unloaded. Care must be taken to maintain a pressurein the receiver l Vsuch that the spring 18 cannot shift the controller valve i9 and cause hunting of the valve 8. l

Shouldthe pressure in chamber 26, passage ll, and reservoir 6 decrease below thepredete'rmined amount, the tension of spring 28 will cause spindle 29 to force diaphragm 2T inward, allowing the regulating pin valve 2d to seat, and air pressure from chamber l5 will leak by piston linto chamber l?, passage'22, and chamber 23 until the pressures are equalized, when spring i8 will return piston lll and valve 19 to the position as shown in Fig'. 2; thus allowing air 'from chamber l5 to pass through port into chamber i3,z and as this pressure in chamber l5 is equivalent to ythe pressure obtaining in the intercooler l between the nrst and second stages of compression, it is apparent that' spring lll will cause discharge valve 8 to seat as usual in the ordinary operation of compressors. Another c advantage of my invention is that there is eeaeiv no tendency for the governor valve to leak pressure except when the pressure in the main reservoir has exceeded the maximum working pressure. rlhe chamber 25, to which the pipe l1 leads, -is air-tight, since it is closed by the diaphragm 27, and the chamber l? is also air-tight when the valve 2eisclosed. i

While l have described my improved-controlling valve mechanism as preferably apilied to a three-stage air co1npressor,'it Will be evident that it is not limited to such construction but is equally applicable to any fluid compressor` ot' one or more stages, and in case oi a single stage compressor the same ultimate reservoir pressure maybe connected to both the diaphragm chamber and valve chamber oi the device.

l-laving lnovv 'described my invention, what l claim as new' and desire to secure by Letters Patent is l. A controlling device for duidcompressors comprisinga compressor discharge valve, a governing' device actuated by the pressure pumped by said compressor, a duid actuated reciprocatingV piston, a control valve actuated by said piston and a regulat- -ing valve actuated by said governing device for controlling y'the operation of said piston.

2. A controlling device for duid compressors comprising a compressor discharge valve, a governing device actuated by the pressure pumped by said compressor, a control valve for delivering iiuid pressure behind said compressor valve and for exhausting pressure therefrom, a duid actuated reciprocatpiston oractuating said control valve and a regulating valve actuated by said governing device for exhausting Yduid pressure from behind said piston and causing said control valve to' exhaust :duid :trom behind said compressor valve. p v

' A controlling device tor duid compressors'comprising a compressor discharge valve, a governing device actuated by the'pressure pumped by said compressor, a tiuid actuated piston, means 'operated by said piston :for controlling the operation or said. discharge valve'and a regulating valve actuated by said governing device or controlling the operation or said.l piston.

li.- ln a multi-stage compressor, a primary stage, a governing mechanism controlled by final-stage pressure, a valve controlled by said mechanism .tor unloading the primary stage and a secondary stage, the clearances of which areI so proportioned that the secondary stage is rendered ineffective by the unloading of the primary stage.

5. ln a multi-stage compressor, a primary stage, a governing device controlled by finalstage pressure for unloading, said primary stage and a secondary stage, the clearances of which vare so proportioned that the secondary stage is rendered ineffective by the unloading of the primary stage.

6. .in a multi-stage compressor, a primary stage, a governing mechanism controlled by tinal-stage pressure, a discharge valve for said primary stage controlled by said mechanism to unload theprimary stage and a plurality ot' stages of successively increasing pressure, the clearances of which are so proportioned that they are rendered inedeetive by the unloading of the primary stage.

7. n combination with a multi-stage compresser,y a governing mechanism comprising a primary-stage discharge valve, a governing device actuated by Vfinal-stage pressure, means for subjecting said discharge valve to primary-stage pressure, a duid actuated reciprocating piston orxcontrolling the operation oil said means and a regulating valve actuated by said governing device to control the operation oi` said piston.

8. ln combination with a multi-stage compressor, a governing mechanism comprising a primary-stage discharge valve, a governing device actuated by final-stage pressure,

vmeans i'or controlling the operation or said discharge valve, a duid actuated piston tor controlling the operation ci said means and a regulating valve actuated by said governing device to exhaust duid iroin behind said piston to cause said piston to open said discharge valve through the agency or said means.

` 9, in combination vvith a multi-stage cornpressor, a governing mechanism comprising Aa primary-stage discharge valve, a governing device actuated by final-stage pressure, means subjected to primary-stage pressure igor controlling the operation or said discharge valve and a regulating valve actuated by said governing device ior controlthe operation or said means..

in testimony Avvluereot i have hereunto set my hand., i

' HERBERT il HERR.

Witnesses i?. iinvnsnnr, llnann lvl. Annen.

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