US3867071A

US3867071A - Pumping system with air vent

Info

Publication number: US3867071A
Application number: US291284A
Authority: US
Inventors: Ezra D Hartley
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-09-22
Filing date: 1972-09-22
Publication date: 1975-02-18
Anticipated expiration: 1992-02-18

Abstract

A pumping system for pumping a liquid comprising a pump, a check valve on the discharge side of the pump, a vent in communication with the discharge side of the pump and with the upstream side of the check valve, and a valve for opening and closing the vent.

Description

ite States Patent 1191 Hartley Feb. 18, 1975 [5 PUMPING SYSTEM WITH AIR VENT 2,776,630 1/1957 Fagan 417/435 1 1 Invent 11444112100 Jaemia 513321231 11/1323 331551121:::::.........i.....::::: 333/22? Los Angeles, Calif. 90046 [22] Filed: Sept. 22, 1972 Primary ExaminerC. J. Husar AssistantExaminer-Richard E. Gluck [21] Appl' 291384 Attorney, Agent, or FirmG0rd0n L. Peterson [52] U.S. Cl 417/2115, 55/170, 137/202,

417/306, 417/435 [57] ABSTRCT [51] Int. Cl. F04b 49/00, BOld 19/00 A P p System for P l P a llquld comprising [58] Field of Search ..417/211.5, 306,435; Pump, a Check valve on the discharge slde of the 55/17 137/202 pump, a vent in communication with the discharge side of the pump and with the upstream side of the 5 References Cited check valve, and a valve for opening and closing the UNITED STATES PATENTS vent- 1,532,439 4/1925 Pardee .1 417/435 4 Claims, 9 Drawing Figures 1 PUMPING SYSTEM WITH AIR VENT BACKGROUND OF THE INVENTION Many liquid pumping systems employ a pump which draws a liquid from an exhaustible supply of the liquid such as a storage tank. One example of such a pumping system is the water system for a vehicle such as recreational vehicles and boats. A water system includes a spring biased check valve downstream of the pump which is used to prevent backflow of water through the pump.

When the water in the storage tank is depleted, the pump draws some air into the system. When the tank is refilled with water, air in the system is trapped between the water in the tank and the check valve. Accordingly, the pump must pump air rather than water. Under these conditions, centrifugal pumps and many positive displacement pumps will not develop adequate pressure to open the check valve, and consequently, the pump cannot deliver water.

SUMMARY OF THE INVENTION The present invention provides a pumping system which eliminates the air lock problem regardless of the type of pump which is used. The user need not open any valves or faucets to accomplish this.

The present invention provides vent means in communication with the pump discharge on the upstream side of the check valve. The vent means may include a vent opening. A valve is provided to open and close the vent opening. The valve is controlled so that it substantially prevents the escape of water from the system and so that air which would ordinarily be trapped within the system can escape. The valve is open under conditions when air lock would ordinarily occur and is closed when water adjacent to the vent opening rises to a level where it might escape through the vent opening.

Although the valve could be manually controlled, it is preferred to employ automatic control means for the valve. This can be simply and advantageously accomplished by means such as a float responsive to the liquid level in afloat chamber adjacent the vent opening. The valve includes a valve element, the position of which is controlled by the float. When the water level in the float chamber is high, the float rises and closes the valve to substantially prevent the escape of water. When the water level in the chamber is lower, the float lowers and opens the valve.

More specifically, in one form the of the invention which is particularly adapted for pumping systems where the pump is below the water level in the tank, only a single valve opening and valve element are used. In this event there is water in the float chamber as long as there is water in the tank. Accordingly, the float is normally held in an upper position so long as there is water in the tank, and consequently, the valve opening is normally closed. However, when the water in the tank is depleted, the float lowers, and the vent opening is opened by the valve. Upon refilling of the tank, water flows to and through the pump and forces the air out through the vent opening thereby avoiding air lock. As there is water at the pump, any air trapped downstream of the check valve can be easily forced out of the system by the water delivered by the pump.

In a second embodiment of the invention, which is adapted for use with pumps above or below the water level in the tank, the vent means includes a pair of vent openings in series. A valve is provided for each of the vent openings. The second valve can be opened by the air pressure developed by the pump when the latter is pumping air. The second valve can also be opened by the float as the water level in the float chamber rises. Thus, the second valve does not prevent the air from being removed from the system.

One important function of the second valve element is that it adapts the pumping system to a situation in which the pump is located above the water tank. In the typical water system, the pump is. cycled off and on as required to maintain the water pressure in a predetermined range. With the pump above the tank and shut off, the water in the pump would run back into the tank if the vent opening were open and a loss of prime would occur. The second valve, however, closes when the pump is shut off and the water in the float chamber drops to a predetermined level with the result that no additional water can drain from the pump under the influence of gravity back into the storage tank. Another function of the second valve which is applicable regardless of pump location is that it closes the system under certain operating conditions to thereby exclude dirt.

Another feature of the invention is that both of the valves are of very simple construction and neither of them employs springs or biasing members. The valve elements are movable to one of the positions thereof under the influence of gravity.

The vent opening should be on the discharge side of the pump so that all air between the tank and the pump discharge can be forced out of the system. If the vent were on the intake side of the pump, it would draw air into the system when the pump was running. The vent opening should be on the upstream side of the check valve so that water can readily flow to the vent and force the air in the system out the vent. The vent opening should be above the float chamber because the air which is to be expelled, being lighter than water, will inherently seek an upper level in the system.

Upon restarting of the pump after refilling of the water tank, the air in the system may tend to cause some foaming. The foam will seek a high elevation in the system and some of it may escape through the first of the vent openings prior to the closing thereof by the first valve. In order to prevent the water component of this foam from being discharged from the system, the present invention provides a foam chamber immediately downstream of the float chamber. The foam can collect in the foam chamber. The second vent opening is provided in the foam chamber and provides communication with the atmosphere outside of the system. To help separate the gaseous and liquid components of the foam, the present invention provides for a tortuous path between the float chamber and the second vent opening.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a perspective view of a pumping system constructed in accordance with the teachings of this invention.

FIG. 2 is a sectional view taken generally along line 2-2 of FIG. 1 showing the pumping unit with no water being supplied thereto and with the pump removed.

FIG. 3 is an enlarged sectional view taken generally along line 3-3 of FIG. 2 with the pump turned off and no water in the tank.

' FIG. 4 is a sectional view similar to FIG. 3 with the pump running under normal operating conditions.

FIG. 5 is a sectional view similar to FIG. 3 showing how air is removed from the system.

FIG. 6 is a schematic view of a pumping system constructed in accordance with the teachings of this invention.

FIG. 7 is a partial sectional view taken generally along line 7-7 of FIG. 2 with the pump running under normal operating conditions.

FIG. 8 is a top plan view of the float and float chamber.

FIG. 9 is a fragmentary sectional view showing a modified form of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 6 shows a pumping system 11 constructed in accordance with the teachings of this invention. The pumping system 11 generally includes a pump 13 having an intake port 15, a discharge port 17, and a filter 19 immediately upstream of the intake port. The pumping system 11 also includes a vent unit 21 intermediate the discharge port 17 and a check valve 23, and a pressure responsive switch 25. The check valve 23 prevents back flow therethrough in a direction toward the pump 13 and is normally biased to a closed position. If desired an accumulator (not shown) may also be used in a manner well known in the art.

The pumping system 11 is adapted for connection to a tank 27 of liquid such as water with such liquid being supplied to the intake port of the pump 13. The pumping system 11 at its discharge side is adapted for connection to a water distribution system which may include one or more faucets 29.

The pump system 11 is also connectible to a source of power such as a battery 31 which supplies electrical energy to the motor of the pump 13 to operate the pump. The pressure switch 25 opens and closes a circuit to the pump 13 to cycle the pump on and off. The pressure switch 25 is responsive to the pressure downstream of the check valve 23 reaching a predetermined level for turning the pump off and is responsive to the pressure downstream of the check valve 23 dropping to a predetermined level to turn the pump on. A manual switch 32 allows the pump 13 to be shut down regardless of the condition of the pressure switch 25.

During normal operation of the pumping system 11, the vent unit 21 does not effect the operation of the system. However, if the tank 27 runs dry, air will accumulate in the pumping system 11 upstream of the check valve 23. When the tank 27 is refilled, the water forces the air to the vent unit 21 which allows the latter to escape with the result that the air will not interfere with pump operation.

A preferred form of the pumping system 11 is shown in FIGS. 1-7. The pumping system 11 (FIGS. 1 and 2) includes a housing 33 of molded plastic material having an inlet 35 and an outlet 37. Conduits 39 and 41 connect the inlet 35 and the outlet 37 to the storage tank 27 (FIG. 6) and to the water distribution system respectively.

The housing 33 includes a main housing section 43 having open ends which are closed by the pump 13 and a rear cover plate 45 (FIG. 3). The upper end of the main housing section 43 is closed by a cover plate 47 which is attached to the main housing section by a plurality of screws 49.

As shown in FIGS. 2 and 7, the main housing section 43 defines a central inlet chamber 51 which communicates with the inlet 35. The pump 13 is mounted on the main housing section 43 by screws 53 (FIG. 3). The filter 19 (FIG. 3) is carried by the pump 13 and the intake ports 15 are behind the filter. The discharge ports 17 of the pump 13 deliver water under pressure to discharge chamber 55 which surrounds the central cham ber 51. The pump 13 may be a centrifugal pump or a positive displacement pump, and in the embodiment illustrated is in the form of a positive displacement roller pump. An annular seal 57 bears against the pump to thereby provide a seal between the chambers 51 and A check valve 59 (FIGS. 26) is in communication with the discharge chamber 55. The check valve 59 includes annular boss'6l formed integrally with the main housing section 43 and defininga valve seat 63. A valve element 65 is urged by a spring 67 toward a closed position shown in FIG. 3 in which the valve element 65 engages the valve seat 63. The spring 67 bears against a disc 69 which is seated on a shoulder 71 and which has a central passage 73 extending therethrough.

An annular retainer 75 holds a resilient diaphragm 77 in position adjacent the disc 69. A plunger 79 is urged against the diaphragm 77 by a spring 81. An arm 83 which is pivotally mounted in the cover plate 45 bears against the outer end of the plunger 79. The pressure switch 25, which may be of conventional design, is also carried by the rear cover plate 45 and is arranged to be actuated by predetermined pivotal movement of the arm 83.

When the pump 13 is not operating, the check valve 59 will ordinarily be closed as shown in FIG. 3. When the pump 13 operates to pump water, the pressure in the discharge chamber 55 increases sufficiently to force the valve element 65 off the seat 63 to allow fluid flow through the boss 61 and into the outlet 37 as best shown in FIG. 7. When the check valve 59 opens, fluid also flows through the passage 73 and against the diaphragm 77 to force the plunger 79 upwardly against the biasing action of the spring 81. The passage 73 is of small diameter and forms a restriction to provide some time delay between a pressure change on the check valve side of the passage and a corresponding pressure change on the diaphragm side of the passage. This pivots the arm 83 to actuate the pressure switch 25 to turn off the pump 13. This occurs when the pressure downstream of the check 59 reaches a preset magnitude. Similarly, when the pressure downstream of the check valve 59 drops below a predetermined level, the spring 81 urges the plunger 79 downwardly to thereby allow the arm 83 to pivot in the opposite direction to actuate the pressure switch 25 and energize the pump.

The main housing section 43 also defines a float chamber 85 (FIGS. 2 and 3) which is closed by the upper cover plate 47. In a preferred orientation of the pumping system 11, the float chamber 85 is at an upper level in the pumping system. A pair of apertures 87 provide communication between the annular chamber 55 and the float chamber 85. Thus, the float chamber 85 communicates with the discharge side of the pump 13 and with the upstream side of the cheek valve 59.

A hollow float 89 which may be constructed of plastic material is mounted in the float chamber 85. The

float 89 is of sufficiently light weight so as to float in the liquid which is being pumped by the pump 13.

The upper cover plate 45 has an inner wall 91 and an outer wall 93 defining a foam chamber 95 therebetween. A first vent opening 97 provides communication between the float chamber 85 and the foam chamber 95, and a second vent opening 99 provides communication between the foam chamber 95 and the atmosphere or the exterior of the pumping system 11. Annular valve seats 101 and 103 are provided around the

vent openings

97 and 99, respectively.

A first valve element 105 is movable between an open position (FIGS. 2, 3 and 5) and a closed position (FIG. 4). The valve element 105 is movable upwardly or to the closed position thereof by the float 89.

A disc-like valve element 107 rests on the valve seat 103 (as shown in FIGS. 2 and 3) to close the vent opening 99. The valve element 107 is movable off of the seat 103 to an open position (FIGS. 4 and 5) by air pressure when the pump is pumping air and/or by a stem section 109 of the valve element 105. The stem section 109 projects through the vent opening 109 and is slidably received in a conical boss 111.

A serpentine passage is provided between the flaot chamber 89 and the exterior of the cover plate 45. To this end, the lower end of the boss 111 extends to a location slightly within the vent opening 97. Accordingly, the vent opening 97 is substantially annular. In addition, the conical boss 111 has a plurality of radical apertures 113. The cover plate 45 defines a circular chamber 115 immediately above the valve element 107 from which the only exit is a relatively small radical aperture 117.

The pumping system 11 can be connected to the tank 27 so that the pump 13 is either above or below the tank 27. Assuming first that the pump 13 is below the tank 27, then during normal operation of the pump, water under pressure is discharged from the pump discharge port 17 and passes through the discharge chamber 55 and the apertures 87 to the float chamber 89. As the water is under pressure, it will accumulate to a substantial height in the float chamber 89 and float the float 89 as shown in FIG. 4. With the water level in the float chamber 85 relatively high, the float 89 urges the valve element 105 to a closed position. In addition, the stem section 109 lifts the valve element 107 off of its seat so that the vent opening 97 is closed and the vent opening 99 is open. If the pump 13 is shut off, the water level in the chamber 85 remains high because the pump 13 is below the tank 27 so drainage back to the tank i will not occur. Accordingly, with the pump 13 below the tank 27, the

valve elements

105 and 107 do not effect normal operation of the pump.

If the tank 27 runs dry, then pressure downstream of the check valve 59 is lost and the pressure switch turns the pump 13 on with the result that the pump draws in some air. Accordingly, the space between the tank 27 and the check valve 59 is filled at least partly with air. The pump 13 may then be shut down by opening the manual switch 32 and the tank 27 is then filled. Because the pump 13 is mounted below the tank 27, water can flow under the influence of gravity from the tank toward the pump 13. The air between the tank 27 and the check valve 59 is forced by the water through the apertures 87 and into the float chamber 85. The head of water in the tank 27 is sufficient to cause the air in the float chamber 85 to pass through the vent opening 97 and to force the valve element 107 off of its seat 103 to allow the air to escape. As the air escapes from the system 11, thewater level in the float chamber increases. This causes the float 89 to float and drives the valve element 105 through an: intermediate position (FIG. 5) in which the stem section 109 is positioned to prevent closure of the valve element 107 and is operative to hold the latter open if the air pressure in the chamber 85 is insufficient to do so. Ultimately, the valve element 105 reaches the closed position (FIG. 4), and in this position, there is no air at the pump 13.

, If the pump 13 is mounted above the tank 27, then the pump 13 should be a self priming pump. With the pump 13 above the tank 27, then upon termination of pump operation water in the float chamber 85 tends to flow under the influence of gravity back toward the tank 27. However, as soon as the water in the float chamber 85 is dropped only slightly, the stem section 109 allows the valve element 107 to return under the influence of gravity to the closed. position as shown in FIGS. 2 and 3. With the vent opening 99 closed, continued flow of water back into the tank 27 is prevented. Accordingly, the valve element 107 prevents the pump 13 from losing its prime each time the pump is turned off.

If the tank 27 runs dry, the pump 13 draws some air into the system. When the tank 27 is refilled. air is trapped between the water in the tank 27 and the check valve 59. However, the air in the system is not under any head or pressure because the pump 13 is above the tank.

When the pump is started, it will pump the air through the apertures 87, the float chamber 85, the vent opening 97 and force the valve element 107 off of its seat 103 to open the vent opening 99. As the air has an escape path upstream of the check valve 59, the pump 13 can then, employing its self priming feature, draw water up to its level and in so doing close the vent opening 97 as shown in FIG. 4.

FIG. 9 shows a pumping system Illa which is a second embodiment of this invention. The: pumping system 110 is identical to the pumping system 11 in all respects except that the valve element 107 has been eliminated. Parts of the pumping system 11a corresponding to parts of the pumping system 11 are designated by corresponding reference numerals followed by the letter a.

With the valve element 107 eliminated, the pumping system 11a is fully adapted for use in systems in which the pump 13 is below the level of the liquid in the tank 27. However, the pumping system 11a is not adapted for use in systems in which the pump 13 above the level of liquid in the tank 27 because without the valve element 107, the pump would lose its prime each time the pump is turned off.

Although exemplary embodiments of the invention have been shown and described, many changes, modifications and substitutions may be made by one having ordinary skill in the art without necessarily departing from the spirit and scope of this invention.

I claim:

I. A pumping system for pumping liquid comprising:

a housing having an inlet and an outlet, said inlet being conneetible to a source of liquid;

a pump having a suction opening and a discharge opening, said pump being mounted in said housing for pumping liquid through said housing from said inlet to said outlet;

wall means on said housing defining a float chamber in communication with the discharge opening of said pump, said wall means having a vent opening therein in communication with the exterior of said housing;

means for blocking said float chamber from direct communication with the suction opening of said pump whereby the only flow path between said float chamber and the suction opening is through the discharge opening;

a float in said float chamber movable in response to the liquid level in said float chamber;

a valve including a valve element movable between a closed position in which the valve element closes the vent opening and an open position in which the valve element allows flow through the vent openmg;

said valve element being drivable toward at least one of said positions thereof by said float, said valve element closing said vent opening in response to a relatively high liquid level in said chamber and opening said vent opening in response to a lower liquid level in said chamber; and

said vent opening being a first vent opening, said valve including a first valve element and a stern, said stem projecting through said first vent opening in both the open and closed positions, means defining a second vent opening in series with the first vent opening, a second valve element disconnected from said stem for closing the second vent opening, said second valve element including a disc.

2. A pumping system for pumping liquid comprising:

a housing having an inlet and an outlet, said inlet being connectible to a source of liquid;

means defining'a discharge chamber in said housing communicating with said discharge opening whereby said discharge chamber receives fluid from said pump;

means defining a float chamber in said housing, said chambers having a commoniwall with an aperture therein to provide communication between said chambers;

said float chamber having a vent opening;

a float in said float chamber movable in response to the liquid level in said float chamber:

a valve including a valve element movable between a closed position in which the valve element closes the vent'opening and an open position in which the valve element allows flow through the vent openmg;

said valve element being drivable toward at least one of said positions thereof by said float, said valve element closing said vent opening in response to a relatively high liquid level in said chamber and opening said vent opening in response to a lower liquid level in said chamber;

a check valve in said housing in communication with said discharge chamber; and

said float chamber and said discharge chamber being above and below said common wall, respectively.

3. A pumping system as defined in claim 2 wherein said discharge chamber has a second wall, said check valve including means on said second wall defining a valve seat and a valve element engageable with said valve seat.

4. A pumping system as defined in claim 3 wherein said vent opening is a first vent opening, said first mention valve includes a first valve element and a stem, said stem projecting through said first vent opening in both the open and closed positions, means defining a second vent opening in series with the first vent opening, a second valve element disconnected from said stem for closing the second vent opening, said second valve element including a disc, said aperture being in a lower portion of said common wall, and means for blocking said float chamber from direct communication with the suction opening of said pump whereby the only flow path between said float chamber and the suction opening is through the discharge opening.

Claims

1. A pumping system for pumping liquid comprising: a housing having an inlet and an outlet, said inlet being connectible to a source of liquid; a pump having a suction opening and a discharge opening, said pump being mounted in said housing for pumping liquid through said housing from said inlet to said outlet; wall means on said housing defining a float chamber in communication with the discharge opening of said pump, said wall means having a vent opening therein in communication with the exterior of said housing; means for blocking said float chamber from direct communication with the suction opening of said pump whereby the only flow path between said float chamber and the suction opening is through the discharge opening; a float in said float chamber movable in response to the liquid level in said float chamber; a valve including a valve element movable between a closed position in which the valve element closes the vent opening and an open position in which the valve element allows flow through the vent opening; said valve element being drivable toward at least one of said positions thereof by said float, said valve element closing said vent opening in response to a relatively high liquid level in said chamber and opening said vent opening in response to a lower liquid level in said chamber; and said vent opening being a first vent opening, said valve including a first valve element and a stem, said stem projecting through said first vent opening in both the open and closed positions, means defining a second vent opening in series with the first vent opening, a second valve element disconnected from said stem for closing the second vent opening, said second valve element including a disc.

2. A pumping system for pumping liquid comprising: a housing having an inlet and an outlet, said inlet being connectible to a source of liquid; a pump having a suction opening and a discharge opening, said pump being mounted in said housing for pumping liquid through said housing from said inlet to said outlet; means defining a discharge chamber in said housing communicating with said discharge opening whereby said discharge chamber receives fluid from said pump; means defining a float chamber in said housing, said chambers having a common wall with an aperture therein to provide communication between said chambers; said float chamber having a vent opening; a float in said float chamber movable in response to the liquid level in said float chamber; a valve including a valve element movable between a closed position in which the valve element closes the vent opening and an open position in which the valve element allows flow through the vent opening; said valve element being drivable toward at least one of said positions thereof by said float, said valve element closing said vent opening in response to a relatively high liquid level in said chamber and opening said vent opening in response to a lower liquid level in said chamber; a check valve in said housing in communication with said discharge chamber; and said float chamber and said discharge chamber being above and below said common wall, respectively.