US3156410A

US3156410A - Pump

Info

Publication number: US3156410A
Application number: US149936A
Authority: US
Inventors: Riche Rene P Le
Original assignee: Pennsalt Chemical Corp
Current assignee: Pennwalt Corp
Priority date: 1961-11-03
Filing date: 1961-11-03
Publication date: 1964-11-10
Anticipated expiration: 1981-11-10

Description

NOV- 10, 1954 R. P. LE RlHE 3,156,410

PUMP

Filed NOV. 3, 1961 FIG.I

' INVENTOR. RENERLE -RICHE BYMMMQ ATTORNEY United States Patent O 3,156,410 PUMP Rene l. Le Riehe, Haddoniield, NJ., assigner, by mesne assignments, to Penne-alt Chemicals Corporation, Philadelphia, Pa., a corporation of Pennsylvania Filed Nov. 3, 1961, Ser. No. 149,936 Claims. tCl. 23u-232) This invention relates to pumps, and more particularly, to vacuum pumps having a gas ballast device wherein the particular improvement resides in means for virtually eliminating noise associated with the operation of valves therein.

it has been standard in the pump industry in recent years to provide vacuum pumps with a so-called gas ballast device wherein a substantial quantity of air on the order of live to ten percent of the capacity of the pump is admitted directly to the compression side of the pump for the purpose of either reducing the amount of moisture that is condensed during the compression stroke or as a means for cleaning up contaminated oil in the pump reservoir. The present invention is particularly adapted to pumps of this type since the air supply is utilized by providing means to introduce an extremely small amount of air into the compression side of the pump. The amount of air introduced is so small that the blank-off of the pump is not appreciably affected; however, the noise associated with the opening and closing of the puppet valves is substantially eliminated.

The present invention is not to be limited to a pump having a so-called gas ballast device, but rather is applicable to a wide variety of pumps having a poppet or check valve in the outlet side of the pump. As a general rule, it is the puppet or check valve in the outlet side of the pump which creates the major amount of noise associated with a pump. I have found that the introduction of a small amount of air corresponding to between .001% and'.1% of the capacity of the pump substantially reduces the noise associated with the valve on the outlet side of the pump. A larger amount of air does not affect the noise level but does reduce the efi'iciency of the pump. Accordingly, the amount of air introduced on the compression side of the pump is critical.

lt is an object of the present invention to provide a pump having novel means for reducing noise associated with the operation of the pump.

it is another object of the present invention to provide a novel noise eliminator for vacuum pumps which is simple, eilicient and inexpensive.

It is another object of the present invention to provide a novel means for eliminating noise associated with the operation of a pump having a so-called ballast device which takes advantage of the source of air associated with the ballast device.

Other objects will appear hereinafter.

For the purpose of illustrating the invention there is shown in the drawings a form which is presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FEGURE 1 is a front elevation view of a vacuum pump incorporating the present invention.

FIGURE 2 is a longitudinal sectional view of the pump illustrated in FlGURE l.

FEGURE 3 is an exploded sectional view taken through the valve mounted on the pump illustrated in FIGURE 1.

FIGURE 4 is a View similar to FIGURE 3, and illustrating another position of the valve element.

Referring to the drawingsin detail, wherein like numeralsindicate like elements, there is shown in FIGURE l a pump designated generally as 1t). Y

The pump 10 isa Vacuum pump having-a .so-called ing 141.

3,156,410 Fatented Nov. l0, 1964 ice ballast device. The pump 10 comprises a pump housing 12 having an oil reservoir housing 14 mounted on an upper surface thereof. The pump housing 12 includes a pumping chamber 16 substantially encircled by a cooling chamber 1S. The pump chamber 16 and the cooling chamber' 1S are separated by a cylinder Wall 17.

The cooling chamber 13 is provided with an inlet port 2t) and an outlet port 22. A rotor shaft 24 is concentrically disposed within the pump chamber 16. lt will be noted that the pump lil is of the eccentric piston-slide type and includes an annular element 26 eccentrically keyed thereto. An annular rotor 28 is rotatably disposed around the element 26 with the outer peripheral surface thereof being juxtaposed to the inner peripheral surface of the cylinder wall 17. A hollow slide 30 is integrally connected at one end with the rotor 28.

The slide 30 is hollow and slidably extends through a cylindrical hinge bar 32. The end of the slide 3l) remote from the rotor 23 is open and in communication with an inlet chamber 34. The inlet chamber 34 is provided with an inlet port 36.

The pumping chamber 16 is provided with an outlet port 33 which communicates with an outlet passage having a poppet valve itl disposed therein. Such outlet passage extends into and communicates with the chamber of the oil reservoir housing 14. The fluids passing from the pumping chamber 16 through the outlet passage into the oil reservoir housing 14- pass through an oil separator 42. The oil separator 42 separates such fluids into oil 4d and air which exits through the outlet port 46 to atmosphere. The oil 44 is conveyed so as to provide an oil seal for the shaft 24 in a manner Well known to those skilled in the art.

A conduit d@ having a valve 5@ therein communicates with the pumping chamber 16 by way of inlet port 52. Conduit 48 and valve Su are illustrated in FIGURES 1, 3 and 4. The inlet port 52 is shown in FGURE 2. The valve 5@ may be any one of a plurality of conventional types of valves. As illustrated, the valve S0 includes a cylindrical valve element 54 rotatably mounted Within a cylindrical bore of the valve housing 55. The element S4 is provided with an actuator handle 56.

When the handle 56 is in the solid line position illustrated in FIGURE 3, a main flow passage 5S in the valve element 54 is in alignment with conduits 48 and 6l). The conduit 6l) terminates at check valve 61 which is adapted to be in communication with a source of air under pressure. When the handle 56 is in the position illustrated in FIGURE 4, the passage 53 is out of communication with the

conduits

48 and 60.

A multi-diameter bleed passage 62 extends through the ball element 5-4 in a direction substantially perpendicular to the longitudinal axis of the passage 5S. Thus, when the handle 56 is in theV position illustrated in FIG- URE 4, the passage 62 is in alignment With the conduits and 6u. When the handle 56 assumes the phantom position illustrated in FGURE 3, neither of the passages S3 and 62 are positioned so as to provide communication between the conduits 43 and 60.

The size of the bleed passage 62 as a function of the capacity of the pump is critical. Thus, the size of the downstream portion of the bleed passage 62 should be capable of permitting a small amount of air to be introduced into the pumping chamber 14S. Such amount of ait should be between .00l%. and .1% of the capacity of chamber 16. Preferably, such amount of air corresponds to approximately one fiftieth of one percent of the capacity of chamber 16. The upstream end of bleed passage 62 has a diameter equal to or less than the diameter of passage 58. Y.

A motor 64 is mounted on top of the oil reservoir hous- The motor d4 isoperatively disposed and is provided with means for rotating the shaft Z4. The remaining elements of the pump 1d not specifically described are conventional in the art and need not be described in detail.

The pump 1t) of the present invention operates as follows:

The motor 64 rotates the shaft 2.4 which in turn rotates the element 26. The element 26 causes the rotor Z8 to rotate therewith. The rotation of the rotor 2d causes air to be removed from a container connected to the inlet port 36. Such air passes from the inlet chamber 3d through the slide 30 to the input side of the pumping chamber 16.

The rotation of the rotor 23 compresses such air and discharges the same through valves 40. The pressure of the compressed air opens the valve ttl which in turn closes as the rotor 28 passes thereby. The rotation of the rotor 2h is in the direction of the arrows in the pumping chamber 16. As the rotor 2S rotates, the slide 30 reciprocates in the hinge bar 32.

With the valve element 54 in the position illustrated in FIGURE 3, a substantial amount of air is introduced in the compression side of the pumping chamber 16 to reduce the amount of moisture condensed during the cornpression stroke. This provides the so-called gas ballast device which is well known to those skilled in the art. To those skilled in the art, the valve 50 is known as a gas ballast valve. When the valve element 54 is in the position illustrated in FGURE 4, a small amount oi air, between .001% and .1% of the capacity of the pump, is introduced into the compression side of the pumping chamber 16. Thus, on a 300 c.f.m. pump, the air bleed would be between .003 and .3 c.f.m. It is believed that this small amount of air acts as a cushion for the reciprocatory movement of a poppet element in the poppet valve 40. The poppet valve dit is opened and closed several hundred times per minute and therefore creates a substantial amount of noise. The extremely small amount of air introduced by the bleed passage 62 unexpectedly reduces the valve noise encountered heretofore.

Since the upstream end of the bleed passage 62 is of a larger diameter, the velocity of the gas decreases as it iows therethrough. This enables dust to settle in the ilow passage 58 and thereby prevents the dust from clogging the downstream end of passage 62. When the valve element is rotated to the position illustrated in FIGURE 3, the accumulated dust will be flushed out by the flow of gas through passage 58.

While the valve element 54 has been illustrated as being a cylindrical valve element, it will be appreciated that valves having rotatable spherical ball valve elements, reciprocating valve elements or pivotable valve elements may be substituted therefor. While the air bleed of the present invention readily accommodates itself for utilization in a gas ballast device of a vacuum pump, it will be understood by those skilled in the art that the air bleed may be utilized with other types of pumps. It is within the scope of the present invention to locate the bleed passage in the valve housing instead of in the Valve element.

The present invention may be embodied in other specie forms Without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

I claim:

l. A pump comprising a housing having an inlet port and an outlet port in communication with a pumping chamber, a pressure responsive valve controlling ilow from said chamber through said outlet port, a movable pumping element in said chamber, means for selectively moving said element to produce a suction side in said chamber adjacent the point where said inlet port is in communication with said chamber and a compression side in said chamber adjacent the point where said outlet port i communicates with said chamber, and means including a conduit in communication with the compression side of said chamber for introducing a controlled amount of gas into said chamber equivalent to less than .1% and more than .001% of the volumetric capacity of said chamber.

2. A pump in accordance with claim l wherein said last mentioned means includes a Valve in said last mentioned conduit, said valve having a movable valve element having a iirst position wherein a substantial amount of gas ballast may be introduced into said compression side of the chamber, said valve element having a second position wherein said controlled amount of gas passes through a bleed passage associated with said valve element into said compression side of said chamber, said controlled amount of gas being substantially smaller than the amount of gas capable of being introduced into said compression side of the chamber when said valve element is in said rst position.

3. A pump in accordance with claim 2 wherein said valve element is rotatably mounted in a valve housing, said valve element having a main flow passage therethrough and a bleed passage therethrough, whereby gas passes through the main ow passage of said valve element in the rst position of said valve element and gas passes through the bleed passage of said valve element in the second position of said valve element.

4. A pump in accordance with claim 3 wherein the upstream end of said bleed passage has a substantially larger diameter than the downstream end of said bleed passage.

5. In a pump comprising a housing having a pumping chamber, a compression side of said pumping chamber, an outlet port in communication with said compression side of said chamber, a pressure responsive valve controlling flow through said outlet port in response to the presure in said compression side of said chamber, and means for introducing a minimum amount of air into said compression side of the chamber to substantially eliminate the noise associated with opening and closing of said valve, said amount of air being between .001% and .1% of the volumetric capacity of said chamber.

6. A pump comprising a housing having an inlet port and an outlet port in communication with a pumping chamber, a pressure responsive valve controlling ow through said outlet port, a rotatably mounted rotor in said chamber, a motor for selectively rotating said rotor to produce a suction in said chamber adjacent the point Where said inlet port communicates with said chamber and a compression side in said chamber adjacent the point where said outlet port communicates with said chamber, and means including a conduit in communication with the compression side of said chamber for introducing only a sutlcient amount of air into said compression side of the chamber so as to substantially reduce the noise associated with the opening and closing of said valve, said amount of air being between .001% and .1% of the volumetric capacity of said chamber.

7. A pump in accordance with claim 6 wherein said last mentioned means includes a valve, said valve including a bieed passage having a capacity only sucient to permit the introduction of air in an amount corresponding to one-fiftieth of one percent of the volumetric capacity of said pumping chamber.

8. A method of reducing the noise associated with thc opening and closing of a pressure responsive valve controlling fiow from the compression side of a pumping chamber of a pump comprising introducing a controlled amount of air to the compression side of the pumping chamber in an amount corresponding to less than .1% and more than .001% of the volumetric capacity of the pumping chamber.

9. in a method of operating a pump comprising the steps of introducing a gas ballast to the compression sidc of a pumping chamber for reducing the amount of moisture condensed during the compression stroke, halting the said chamber in communication with said last mentioned means and said means for introducing a controlled amount of air into said chamber.

References Cited in the tile of this patent UNITED STATES PATENTS 2,070,151 Westin Feb. 9, 1937 2,779,533 Ziock Jan. 29, 1957 3,042,292 Lorenz July 3, 1962 3,045,897 Wood July 24, 1962

Claims

1. A PUMP COMPRISING A HOUSING HAVING AN INLET PORT AND AN OUTLET PORT IN COMMUNICATION WITH A PUMPING CHAMBER, A PRESSURE RESPONSIVE VALVE CONTROLLING FLOW FROM SAID CHAMBER THROUGH SAID OUTLET PORT, A MOVABLE PUMPING ELEMENT IN SAID CHAMBER, MEANS FOR SELECTIVELY MOVING SAID ELEMENT TO PRODUCE A SUCTION SIDE IN SAID CHAMBER ADJACENT THE POINT WHERE SAID INLET PORT IS IN COMMUNICATION WITH SAID CHAMBER AND A COMPRESSION SIDE IN SAID CHAMBER ADJACENT THE POINT WHERE SAID OUTLET PORT COMMUNICATES WITH SAID CHAMBER, AND MEANS INCLUDING A CONDUIT IN COMMUNICATION WITH THE COMPRESSION SIDE OF SAID CHAMBER FOR INTRODUCING A CONTROLLED AMOUNT OF GAS INTO SAID CHAMBER EQUIVALENT TO LESS THAN .1% AND MORE THAN .001% OF THE VOLUMETRIC CAPACITY OF SAID CHAMBER.