US2318251A - Air exhausting apparatus for pumping systems - Google Patents

Description

T. F. MOORE May 4, 1943.

AIR EXHAUSTING APPARATUS FOR PUMPING SYSTEMS Filed Dec. 26, 1940 2 Sheets-Sheet l May 4, 1943.

T. F. MOORE AIR EXHAUSTING APPARATUS FOR PUMPING SYSTEMS 2 Sheets-Sheet 2 Filed Dec. 26, 1940 il i //A//// Patented May 4, 1943 UNITED STATES rarest" oFricE AIR EXHAUSTING APPARATUS FOR PUMP- ING SYSTEMS This invention appertains to apparatus for use in exhausting air from hydraulic pumping systems, and more especially, to a novel valve arrangement and automatic control therefor which constitutes a marked improvement over the various forms of float valves heretofore employed in pumping systems, as disclosed in my prior Patents Nos. 1,890,125, 1,890,126 and 1,940,007.

While the invention is capable of general application to pumping systems, its use is most advantageous in pumping systems for removing water from marshes, swamps and other repositories, preparatory to trenching and excavating as required for the construction of sewers,'water mains, foundations for buildings, dams, and other structural work.

In those cases where difliculties are encountered by reason of the presence of excessive amounts of water in the soil, it is now more or less common practice to sink a suitable number of wellpoints into the ground in the zone of the excavation or trenching work for the purpose of withdrawing the water from the ground and directing the same to some other point where it will not interfere with the work. The wellpoints are usually connected at their upper ends to one or more headers or conduits, which in turn are connected to a suitable pump, usually a centrifugal pump having a capacity suflicient to handle the volume of water which is to be removed from the ground through the wellpoints. Surface water maybe drawn ofi by what is commonly known as open pumping, as distinguished from wellpoint systems, and it is to be understood that the present invention is applicable to open pumpine systems as well as wellpoint systems.

In the use of the pumping systems above referred to, it becomes necessary to prevent accumulations of air in the pump in order to maintain a maximum working efiiciency of the pump. This is usually accomplished by means of a suitable air exhausting apparatus, which includes a vacuum pump which is so connected with the main pump as to exhaust the air from the latter as it accumulates, and always maintain the main pump primed to "assure maximum working efficiency of the latter. Various means of accomplishing this end have been disclosed in my prior patents hereinabove referred to, and each of which particularly concerns a float valve construction which is automatically controlled bythe rise and fall of Water in the float chamber,

and which prevents the water from gaining ac cess to the vacuum pump, this being essential to the satisfactory operation of the air exhaustion means. I have found through the use of my prior inventions that considerable difficulty is encountered in releasing the float valve when the valve has been closed under conditions which would otherwise cause the water to enter the vacuum pump.

In other words, the suction action of the vacuum pump causes the valve to be held too tightly against its seat, and the sensitivity of the usual controls for this valve is materially impaired.

The primary object of the present invention is to attain the same general objectives described in my prior patents, while at the same time establishing a more eflicient balance of the opposing forces acting upon the float valve, and thus assuring easier operation thereof.

A further object of the present invention is to provide a float valve construction of a more dependable character for automatically and positively preventing theentrance of water into the vacuum pump, while at the same time preventing accumulation of any appreciable quantity of air in the main pump of the pumping system, said float valve construction being such that the weight and size of the float can be reduced to a minimum without impairing its efliciency of operation. I r

A still furtherobject of the invention is to provide an improved, automatically operable float valve construction for pumping systems of the type generally described above, which is 'so constructed that the'vacuum pump-will at times be takingair partly from the atmosphere and partly fromthe accumulations in the main pump of the system so that a more sensitive balance of the valve is obtained and the valve will be more readily responsive to the rise and fall of water in the float chamber as the accumulations of air in the main pum are respectively reduced and increased according to the conditions which result in the entrance of air at the inlets and joints of the pumping system or of the main pump itself. Other objects and advantages of the invention will be hereinafter described and the novel features thereof defined in the claims,

In the drawings: Figure l is a view, partly in elevation and partly in section, of a pumping system embodying my invention; v Figure 2 is an enlarged longitudinal vertical sectional view of the float chamber and float generally similar to Figure 2, taken at right angles to the view shown in Figure 2;

Figure 4 is a fragmentary enlarged vertical sectional view of the upper portion of the float chamber and float valve, with the float valve shown in a raised position, such that the upper end of the float chamber is closed against withdrawal of air therefrom by the vacuum pump, while at the same time permitting air to be drawn into the vacuum pump from the atmosphere;

Figures 5, 6 and 7 are horizontal sectional views, taken respectively on the lines 5, 6-6 and 1-1 of Figure 2.

Like reference characters designate corresponding parts in the several figures of the drawings,

In order that the invention may be best understood, there is illustrated in Figure 1 a typicalpumping system embodying a conventional form of centrifugal pump, which is designated I, and a conventional or other suitable type of vacuum pump, designated 2, the latter having a capacity suflicient to prevent the accumulation of any excess quantity of air in the pump l which might reduce the efficiency of the latter. The impellers of both pumps maybe driven by a common source of power, such as a suitable motor (not shown),

' and to this end the pumps may be connected. to-

gether by a shaft a, shownin broken lines.

An intake pipe 3 leading from the wellpoints or other intake at the source of water which is to be directed through the pumping system is connected tothe suction side of the pump I, and the intake pipe includesa T-section 4- located near the pump I. The bottom of, the T-section 6 is extended downwardly to form a sump 5, and rising upwardly from theupper side of the T-section isa standpipe 6. defining thereina float valve chamber 6'.

Anoutlet pipe or conduit 1 is connected to the pressure side of the pump l, and preferably includes a check valve 8 to permit the outflow of water through the pipe 1-, whilepreventing. back-- flow of water and air to-the pump. The standpipe 6 isin open communication at its lower end with the intake pipe 3 through the opening 9, and its upper end terminates at a predetermined distance above the level of the pump I. To prevent sticks, stones andother refuse from entering the float. chamber in the standpipe 6, I preferably provide a screen or grid H1 in the T-section 4, and thebottom of the sump 5 is preferably providedwith a removable plug or cap II to permit the accumulations of refuse to be removed therefrom from time to time, as may be required.

Referring. now to the other figures of the drawings which are on a more enlarged scale, the upper end of the standpipe 6 is provided with a cap plate l2, preferably removably attached thereto in any suitable manner, as by means of the bolts l3. To maintain a good seal between the cap plate l2 and, the upper end of the standpipe 6, a gasket l4 may be interposed. therebetween.

Centrally arranged in the cap plate I2 is a plurality of apertures l5 which serve to establish communication of the upper end of the standpipe 6, through the cap plate, with a chamber 5- which isdefined by a tubular extension [1 on the upper side of the cap plate. Leading from the chamber 16 is a suction pipe l8 which is connected to the suction side of the vacuum pump 2. A check valve l3 may be interposed, if desired, between the vacuum pump 2 and the chamber I6 at the upper end of the. standpipe 6.

Disposed in the extension I! above the suction pipe I8 is a partition 20, having a central valve seat 2! formed therein, and the peripheral wall of the extension I! is further provided with a plurality of apertures 22 located above the partition 20 and establishing free communication between the space within the tubular extension above the partition 20 and the atmosphere. The upper end of the tubular extension is closed in any suitable manner, as by means of the screw cap-23.

Operating vertically in the valve seat 2| in the partition I! is a valve stem 24, having a valve head 25 formed on its upper end for cooperation with the valve seat 2|. The lower portion of the valve stem 24 passes loosely through an opening in the cap plate I2, and continuing, passes loosely through an opening in an annular valve member 26, whiohdspreferably composed of resilient material such as rubber or other suitable flexible composition. A jamb nut 21 i mounted on the valve stem 24 within the annular valve member 26. The lower end of the valve stem 24 passes through thebottorn of the annular valve member 26, and also extends through the upper end of a second annular collar-or ring 28, the latter also being composed of resilient material such as rubber or the like. A second jarnb nut 29 is threadedly received, onto the lower extremity of the valve stem 24, and serves to clamp. the bottom of the annular valve member 26 and the top of the annular collar 28 against the jamb nut 21.

Attached to the lower side of the annular collar 28 is a float rod 30, having jamb nuts 3| and 32 threadedly received onto the upper end of the same and located respectively at the inside and outside of the bottom portion of the annular collar. The float rod carries at its lower end a float 33, they float rod referably passing through the floatand havin jamb nuts 34 and 35 thereonfor enga ing the up er and lower sides of the float respectively; As illustrated, the float is somewhat smaller in size than the interior diameter of the standpipe 6, so that the water will be free to rise and fall in the standpipe and thereby impart corresponding rising and falling movements to the float. Disposed within the standpipe 6 is a plurality of annularly spaced cage rods 36, each having its upper end bentinwardly and hooked into an, eye 31 fixed to the lower side of the cap plate 12. The lower ends of the cage rods are likewise bent inwardly for engagement with a spider 38. The spider 38 is so positioned that when the water level falls in the standpipe to a point suflicient to cause; the valve head 25 to seat on its seat 2 l-, the bottom of the float 33 will rest upon the spider without unduly distorting the annular collar 28.

In the operation of the pumping system, when the pump l and suction device 2 are running, and the intake 3 is in communication of a body of water to be removed, such water will be drawn through the intake conduit into the pump 4 and discharged from the latter through the outlet or pressure conduit 1 which leads to any convenient point for disposal of the Water as waste. Due to the operation of the suction device or vacuum pump 2, a partial vacuum is created. in the suction, pipe 18, chamber l6 and float chamber 6, thereby cau in mor or e s of the Water, o r from the intake conduit 3, through the opening 3 in the upper side of the T-section 4, and into the float chamber. When the water rises a sulficient distancev in the float chamber 6, the float 33 will rise, causing the valve stem 24 and annular valve member 25 to rise until, by a continued upward movement of the float, the upper side of the annular valve member 26 i pressed against the lower side of the cap plate l2, as illustrated best in Figure 4 of the drawings. During the upward movement of the float 33, the annular elastic collar 28 acts as a spring, this element having-sufiicient resistance to distortion or compression to yieldably transmit the motion of the float rod 39 to the valve stem 24. When suflicient upward pressure is exerted upon the float 33 by the rise of the water level in the float cham her 6', the annular valve member 26 will be compressedto such an extent that the jamb nut 21 will bear against the upper portion of this valve member 26 and force the latter tightly against the lower side of the cap plate I2 in the zone of the apertures Hi. This eflectively seals or closes oh the apertures I5 and the opening through which the valve stem 24 normally loosely extends through the cap plate, thereby positively preventing any water from passing from the float chamber 6' into the upper chamber it, from which it would otherwise gain access to the vacuum pump 2 and cause substantial loss of elficiency of the vacuum pump.

As the valve stem 2s rises in blocking the apertures i5 and the opening for the valve stem, the small head 25 on the upper end of the valve stem is moved away from its seat 21 in the partition 29. When this occurs, atmospheric air will be admitted through the ports 22 into the space above the partition 2!! in the tubular extension l1, and from this space, the air may then pass freely through the opening through which the valve stem 24 loosely passes, into the chamber It which is in opencommunication with the vacuum pump 2. The admission of atmospheric air as just described serve to relieve the float valve 28 from excessive vacuum influence of the suction device 2, and prevents the valve member 25 from being pressed too tightly against its seat on the under side of the cap plate I2 over the openings in the latter. The

action occurs more or less progressively in that j as the float valve 25 begins to close and the valve head 25 on the upper end of the stem 24 begins to open, the withdrawal of air from the float chamber 6' under the influence of the suction produced by the vacuum pump 2, begins to rev1 duce until more and more atmospheric air is admitted past the valve head 25 by the continued rise of the water level in the float chamber, until the upper end of the float chamber 6 is completely blocked by the float valve 26 against the withdrawal of air therefrom, and the vacuum pump is sucking air entirely from the atmosphere.

Now 'as air accumulates at the pump I in consequence of the entrance of air into the intake conduit 3, through the joints of the system, and bearings or other parts of the pump itself, the air will rise in the standpipe 6 and build up a pressure in the upper end of the float chamber 6. To facilitate the withdrawal of the air from the pump I into the standpipe 6, a small .pipe 39 may be employed to connect the top portions of the pump at the upper level of the intake, to the standpipe, as shown in Figure 1. The use of this pipe 39 is more or less optional, as it is not required in certain types of centrifugal pumps.

As the air accumulates in the upper portion of the float chamber 6', it depresses the water level, and the float 33 descends, thus allowing the float valve 26 to move away from and uncover the apertures IE to allow the air to again pass in partition 20 5 into the chamber Hi from which it is Withdrawn through the suction pipe I 8 by the vacuum pump 2. As the float valve 26 descends, -the valve head 25 on the upper end of the valve stem 24 progressively blocks oil" the intake of atmosphericair through the ports 22, until when fully closed, the vacuum pump 2 will be taking air entirely from the upper portion of the float chamber 6'. The operation of the float valve is fully au-i tomatic, and by reason of the employment of the relief valve 25 to control the communication of the vacuum pump 2 with atmospheric air, there is established a substantial balance-of opposing forces acting upon, the float valve 26, which ma-' terially reduces the force necessary to open the float valve, once it has been closed. This has theadvantage of greater sensitivity to changes of air accumulations in the system, while" atthe same time admitting of the use of a float of relatively smaller size and less weight than has heretofore been required without impairing the emciency of operation.

Inicase the volume of water entering the intake pipe 3 is insuflicient to-cover the mouth of the intake, it is evident that greater or less volumes of air will be drawn into the intake with the water, under which conditions'the float 33 will be more or less violently rais'ed or lowered by the rapidly varying volumes of water or air entering the float chamber 6. The shock of these violent movements of the float is partially absorbed by the elastic collar 28 which connects the upper end of the float rod 3|] with the lower end of the valve stem 24, thereby prolonging'the life of the moving parts of the apparatus, and rendering its operation more reliable and eflicient. Thisinflow of external air into the intake is particularly prevalent in open pumping. 1

In addition to assuring the effective Withdrawal or exhaustion of air from the pumping system, my invention further serves to maintain a sulficient water level in the float chamber which will insure a continuous priming of the pump I, and thus maintain the working efficiency of the pump at its maximum.

While the specific details of the invention have i been herein shown and described, the invention is not confined thereto, as changes and alterations may be made without departing from the spirit thereof as defined in the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patentis: r 1. In apparatus of the class described, an upright float chamber, float valve means disposed in said chamber and operable by the change of liquid level therein for establishing and interrupting the suction efiect of a suction device, said float valve means including a resilient valve member of annular form arranged with its axis substantially horizontal, a valve seat disposed at the upper end of the float chamber and overlying the resilient valve member aforesaid for engagement with the upper side of the resilient valve member, a float connected to the diametrically opposite lower side of the valve member aforesaid to cause movement of the resilient valve member towards and away from the valve seat responsive to changes in the liquid level in the float chamber, said float serving to progressively collapse the annular valve member on engagement of said annular valve member with the valve seat and continued rise of the float in the float chamber,

' and pressure controlling means responsive to the float valve means for relieving the float valve means from excessive vacuum influence of the suction \device to assure operation of the float valve means in reestablishing the suction effect of the suction device on closing of the float valve means with respect to thevalve seat.

2. In apparatus of the class described, an up right float chamber, float valve means disposed in said chamber and operable by the change of liquid level therein for establishing and interrupting the suction efiect of a suction device, said float valve means including a resilient valve member of annular form arranged with its axis Substantially horizontal, a valve seat disposed at the upper end of the float chamber and overlying the resilient valve member aforesaid for engagement with the upper side of the resilient valve member, a float having a yieldable connection with the lower side of the valve member aforesaid to cause movement of the resilient valve member towards and away from the valve seat responsive to changes in the liquid level in the float chamber, said yieldable connection afore said being sufliciently rigid to cause collapsing of the annular valve member on engagement of the valve member with the valve seat and continued'rise of the float in the float chamber, and pressure controlling means responsive to the float valve means for relieving the float valve means from excessive vacuum influence of the suction device to assure operation of the float valve means in reestablishing the suction effect of the suction device on closing of the float valve means with respect to the valve seat.

3. Apparatus as defined in claim 2, in combination with a cage suspended in the float chamber about the float and engageable with the float to limit downward movement of the float beyond a predetermined position in the float chamber, and thereby preventing undue distortion of the annular valve member and its yieldable connection with the float.

4. App ratus as defined in claim. 2, in combination with a valve stem forming a part of the pressure controlling means, mounted for free axial movement in the upper end of the float chamber and loosely extending through the valve seat engaging upper side of the annular valve member and fixed to the diametrically opposite lower side of the valve member, and means on the valve stem and located Within the annular valve member for exerting a clamping pressure against the overlying valve seat engaging upper side of the annular valve member to urge the same into flrm contact with its seat incident to the rise of the float in the float chamber and collapse of the annular valve member responsive to the rise of liquid level-therein.

5. Apparatus as defined in claim 2, wherein the yieldable connection between the float and the valve member comprises a resilient connecting member of annular form interposed with its axis substantially horizontal between the float and the valve member and having operative connection with the float and valve member at the lower and upper sides respectively of the annular connecting member aforesaid.

6. In a float valve assembly for use with pumping systems, an upright float chamber having a liquid inlet at its lower end and provided at its upper end with a closure member having at least one port therein to establish communication therethrou-gh with the upper end of the float chamber, means on the upper side of the closure member for defining a chamber communicating with the port aforesaid in the closure member, said last named chamber having an air outlet at one side thereof for the withdrawal of air accumulations from the float chamber through the port in the closure member, means extending above the last named chamber aforesaid for defining another chamber having continuous communication with atmospheric air, the latter chamber having a port at the bottom thereof for establishing communication with the chamber therebelow, float valve means in the float chamber including a flexible valve and a float having resilient connection therewith for automatically closing and opening the port in the closure member responsive to the rise and fall respectively of the liquid level in the float chamber, and valve means including a valve member disposed in the uppermost chamber and coacting with the port at the bottom of the latter chamber, said valve member being connected to the float valve means and automatically operable thereby for admitting atmospheric air into the chambers above the closure member in proportion to the closing of the port in the closure member by the float valve means. 7

7. Apparatus as defined in claim 6, wherein the flexible float valve comprises a resilient valve member of annular form disposed for tangential engagement with the lower side of the closure member to yieldably and progressively distort the annular valve member and thereby obstruct the port in the closure member responsive to rise of the liquid level in the float chamber.

THOMAS F. MOORE.

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