US2656794A

US2656794A - Pneumatic pumping equipment

Info

Publication number: US2656794A
Application number: US186327A
Authority: US
Inventors: Jr Joe Williamson
Original assignee: Individual
Current assignee: Individual
Priority date: 1950-09-23
Filing date: 1950-09-23
Publication date: 1953-10-27
Anticipated expiration: 1970-10-27

Description

1953 J. WILLIAMSON, JR

PNEUMATIC PUMPING EQUIPMENT 3 Sheets-Sheet 1 Filed Sept. 25, 1950 Oct. 27, 1953 J. WILLIAMSON, JR

PNEUMATIC PUMPING EQUIPMENT 3 Sheets-Sheet 2 Filed Sept. 25, 1950 zmwzawi I wax/U v and W af/m/egza require careful maintenance.

Patented Oct. 27, 1953 UNITED STATES PATENT OFFICE PNEUMATIC PUMPING EQUIPMENT Joe Williamson, Jr., Daytona Beach, Fla. Application September 23, 1950, Serial No. 186,327

This invention relates generally to pneumatic pumping apparatus, and has particular application to pumping and lift stations such as are used in connection with municipal sewerage systems.

Under current practices, sewerage systems are of various types, and employ various means for conveying the sewage materials to the point of final disposition. For example, where geographic conditions permit, simple gravity systems can be used. In other localities, pumping is required. This may involve the use of pressurized lines with pumping stations, or unpressurized lines with lift stations, and there may be combination systems. In lift station systems, the lift stations are spaced at intervals, and the sewage flows by gravity, in lines which are vented to the atmosphere, from one station to the other, being elevated at each successive station in order to provide sufiicient head to effect flow to the next station. Pumping stations, in contrast with lift stations, are capable of pumping against substantial back pressure, and hence, can be used in many instances where the less adaptable lift station is unsuitable.

Because of the intermittent nature of sewage flow, it is necessary to utilize intermittently operable pumping mechanisms for use in sewerage systems must include a receiver of some sort for collecting and retaining the material to be pumped between operations. At the present time, centrifugal pump mechanisms having tank type receivers or tank-type pneumatic ejectors constitute the most statisfactory known pumping means for the purpose, and one or the other is i generally used in most sewage lift and pumping stations. The centrifugal pump mechanisms are subject to clogging due to the presence of solid materials in the sewage and their installation requires the provision of large collecting tanks. Moreover, the centrifugal pumping mechanisms While the tanktype pneumatic eiectors are not subject to clogging and require very little maintenance, they are inherently very expensive, and. their installation in below-ground locations, which is also necessary in the usual municipal sewerage systems, requires the construction of large diameter manholes or vault structures which further increase the expense involved. As a result, serious 17 Claims. (Cl. 10325) capable of being used in municipal sewerage systems as an underground lift or pumping station. More specifically, there is a very great :need for a low-cost pumping mechanism, utilizing largely standard parts and fittings capable of use as a sewage lift or pumping station, that can be installed in a low-cost underground structure such as a standard-type manhole. The provision of pumping equipment capable of meeting these requirements constitutes the principal object of the invention.

As will hereinafter appear, the above and other objects of the invention are accomplished through the provision of a new type pneumatic ejector mechanism which, among other novel features, employs a section of the piping system with which it is used, as a receiver for the material being pumped, and at the same time, is capable of being installed without the use of oversize, non-standard manhole or vault structures. The invention makes possible the construction at very low cost of both small and large capacity lift and pumping stations, which can be easily and economically located underground.

The various features and advantages of the invention will be made further apparent in the accompanying drawings and following description of certain illustrative embodiments thereof.

In the drawings:

Fig. 1 is a side elevational view, certain parts being broken away and others shown in section, of a portion of a sewerage system provided with a pumping station in accordance with the invention;

Fig. 2 is a sectional view of the pumping station shown in Fig. 1, taken along the line 22 of that figure;

Fig. 3 is a fragmentary sectional view taken along the line 3-3 of Fig. 1;

Fig. 4 is a diagrammatic illustration of a control circuit for the pumping station shown in Figs. 1 to 3;

Fig. 5 is a side elevational view, certain parts being shown in section, of a portion of a sewerage system embodying a lift station in accordance with the invention;

Fig. 6 is a diagrammatic illustration of the control circuit for the lift station; and

Fig. 7 is a diagrammatic view, similar to Fig. 2, showing a modified pumping station.

In Figs. 1, 2, and 3 of the drawings, there is illustrated a portion of a sewage or other liquid transporting system which includes a pumping mechanism I embodying various of the features of the invention. The pumping mechanism I here shown is operable to pump against a substantial back pressure and hence would normally be classified as a pumping station, although it will be understood that the usual pumping station can also be used as a lift station. The mechanism l is fabricated from standard parts and fittings, and is, arranged to be connected to an inflow line, illustrated at 3, and to an outflow line, illustrated at 5. In a typical system the inflow line 3 might constitute a stub or branch main which collects sewage from a localized area, and the outflow line might constitute a pressurized main line leading to a sewage disposition point.

The control and operatingmeansfor-the pumping mechanism 1 is positioned within a pair of spaced wells or manholes, 1 and 9. The arrangement is such that the pumping mechanism is actuated at selected. times. in response to the operation of a control system 12 which alternately. connects the pumping mechanism tov a source of pressure air. and to the atmosphere, the connection being made through a suitable pipe arrangement is. In the. illustrated structure, the source of pressure air. is an air compressor 13 which is supported in the man-hole. 1. However, any suitable source of pressure air may be used.

The manholes, 1 and 9, are standard type, fourfoot manhole structures of reinforced concrete construction. Each includes a vertically extending, concrete casing 11- which is disposed below the level of the ground 13, a topsection or cap 19 which is closed: by a removable cover 2i, and a bottom section 25. While. the illustrated, manholes are of concrete construction, theymay be made of brick or other suitable construction material.

The pumping mechanism 1 includes an elongated, generally horizontally'extending section of pipe 21, which extends between the manholes 1 and 9 and which is used asa receiver for material being pumped and as a flow conduit between the spaced'manholes 1 and 9'. The pipe 21"may be of any desired size orzlength depending upon the capacity desired in the system, and in, the illustrated unit, the pipe 21' is shown substantially larger than the inlet and outlet-lines 3. and 5, although the larger size of'receiver pipeis not a fundamental requirement.

The end of the pipe 21 which is disposed at the manhole 1 is connected to an inlet assembly 29 and the end of the pipe which is disposedadjacent the manhole 9 is connected to an outlet assembly 31. The inlet and outletassemblies 29 and 3| are adapted to control the flow of sewage or other liquid into and out of the pipe 21.

In order to achieve optimum operation of the pumping mechanism I, particularly with regard to handling sewage, it is important that the pipe 21 slope downwardly from the inlet assembly 29 to. the outlet assembly 3|. The slope of the pipe 21 is necessary in order to assure complete discharge of the pipe 21 and satisfactory removal of various materials such as sand, grit, and solids which might otherwise accumulate on the bottom of the pipe 21 and eventually interfere with operation of the pumping mechanism 1. The slope of the receiver pipe will cause surges of incoming sewage which will sweep solids continuously toward the outlet. For more satisfactory operation, it has been found that the pipe 21 should be inclined downwardly at least one inch p. ne

4 hundred feet and not more than about ten feet per one hundred feet.

The inlet assembly 29 includes a shutoff valve 33 which may be of the gate valve type, as illustrated in Figs. 1 and 2, the valve 33 being controllable from the ground level. In this connection, a vertical casing 35, proportioned to receive a shutoff key (not shown), extends from the ground level to the valve 33. One side of the valve 33 is connected to the inlet pipeline 3:, and the other side of the valve is connected to one end of a short pipe 31, the other end of the pipe 31 being connected to a uniflow or check valve 35. The uniflow valve- 39 is provided to prevent the back flow of the material being pumped into the inlet pipeline 3, and may include a swingable flap Al or; equivalent sealing member.

The uniflow valve 39 shown in Fig. l is of the return-bend type and this construction insures that the pipe 21 will be completely filled. The return-bend typeiof checkvalve also makes possible easy disassembly for clean-out purposes. Itwill be understood that other-suitable types of check valve may be used with the-inlet assembly 29.

The inlet assembly 29' also includes a. flanged T-fittin'g 43 which. connects the outlet of the uniflow valve 39. to the pipe- 21 which. serves as a receiver for the pumping mechanism I. Since the pipe 21. and the outlet of the checkvalve39 are of different. sizes, theT-fitting 43 is of the reducing type in the illustrated structure. The third opening in the T-fitting 43,- is upwardly directed and is connected to a short pipe-section 45. which serves to define av vertical chamber. The upper end of thepipe, section 45 is sealed by a blind flange. 41- which is provided-with several apertures adapted to receive control elements of the control, system 12 and an air inlet, and outlet pipeline as will hereinafter be described.

The outletassembly 3! is connected to the discharge conduit 5; through a riser pipe-43 and an elbow 5I and to, the pipeline, 21. Adjacent the outlet assembly 3| means are provided which serve to reduce the cross-sectionaL area of the flow path to effect'increased velocities in theliquidbeing pumped. In this connection, an eccentric, flanged reducer 53 is provided in theillustratedzunitat the outlet end of the pipe 21, this reducer, decreasing the cross-sectional area of the flow. path of the sewage while forming a continuation of thebottom portion of the pipe 21. This is. accomplished in thereducer 53, illustrated, by fabricating it in the shape of a frustrum ofa cone, the planes of the bases of the frustrurn being parallel to one another and being perpendicular to an element of theconical surface which forms an extension of the lowermost portion of the pipe- 21. This arrangement of the reducer 53 assures complete drainage of the pipe 21 through the reducer-53.

The outlet-end (smallarea end) of the reducer 53 is connected toa flanged, double sweep cross fitting 55'which is positioned as shown inFigs. l, 2, and 3 of the drawings. The lowermost opening of the cross fitting 55 is connected by a elbow or U-bend 51 to the lower portion of the riser pipe 49. The connection to the riser pipe 49 is effected througha Dresser coupling .59 (Fig. 3) which permits the bolt holes in the flanges of theconnecting pipes to be-aligned. In the illustrated structure, the elbow 51 is of the reducing type tofurther reduce the cross-sectional. areaof the flow path. Intermediate the Dresser coupling 59 and the lowermost end of the riser pipe 49 there is provided a uniflow or check valve 6 I preferably of the swinging flap type, and a shutoff valve 63 which is preferably a gate valve (Figs. 1 and 3).

The provision of the reducer 53 and the 180 reducing elbow 51 insures that high velocities are obtained in the outlet assembly and aids in making possible the pumping of sewage containing a relatively large proportion of solid materials. The riser pipe 49 is also of reduced diameter, as shown, to cause increased velocity of flow through the riser pipe. In addition, the 180 reducing elbow provides a trap which prevents pressure air from escaping from the pipe 21 until it is essentially completely emptied, thereby causing the pipe 21 to empty completely, or very nearly so, on each cycle of the equipment.

The uppermost opening of the cross fitting 55 in the illustrated structure, is closed by a blind flange 65, this flange providing a convenient means for cleaning out the outlet end of the sys tem. An electrode chamber 51 for receiving one of the control elements of the control system is connected to the remaining opening of the cross fitting 55 as shown in Figs. 1, 2, and 3, a screen or strainer cs (Fig. 3) being provided intermediate the electrode chamber 61 the cross fitting 55. The screen 58 prevents solid materials from entering the electrode chamber 51 and interfering with the operating of the control electrode. In the illustrated structure, the electrode chamber 61 is defined by a short length of flanged pipe 69, one end of which is connected to the cross fitting 55 and the other end of which is closed by a blind flange 1 I. The screen 58 is supported between the flanges on the cross fitting 55 and the pipe 69. A dome 1G is provided on the upper side of the pipe 69 to provide an air trap and one of the control elements is supported in an opening (not shown) in this dome.

The manhole 1 at the inlet end of the unit is provided with a supporting shelf 13 which is attached to the walls of the concrete casing I1 2. suitable distance below the top section I9. The air compressor I3 is attached to this supporting shelf and a vent 15 is provided in the top section I9 of the manhole above the compressor.

The air compressor I3 may be any of several commercially available types, the function of the compressor being merely to supply sufficient amounts of pressure air to effect operation of the ejector equipment. In the illustrated apparatus, the compressor I3 is a motor driven rotary compressor of the type shown in U. S. Patent No. 2,385,905, however, other types of compressors or a central air supply system may be employed. The compressor I3 includes an inlet pipe 11 having an intake filter 19 which is preferably disposed below the vent 15 in the top section of the manhole 1; a main outlet pipe 8! having a safety valve 83 for venting air from the outflow line under abnormal pressure conditions and a check valve 85 for preventing back flow from the system into the compressor I3; and an auxiliary outlet conduit 86 of the type shown in Patent No. 2,385,905.

The piping arrangement I I is provided for alternately connecting the pipe section 21 to the compressor I3 and venting it to the atmosphere thereby to effect its operation. The piping arrangement I4 includes a generally vertically extending pipeline 81 which is connected to the flange 41 on the top of the short pipe section 45 and to the main outlet pipe SI of the compressor l3. A strainer 89 of conventional construction is disposed in the pipeline adjacent the upper end and the flange on I of the pipeline 81 and one end of an exhaust pipeline 9| is connected into the pipeline 81 above the strainer 89, the other end of the exhaust pipe being in communication with the atmosphere.

A pneumatically operated diaphragm valve 93 is disposed in the exhaust or vent line 9i and the operating chamber of this valve is connected to the auxiliary outlet conduit 86 on the compressor by the conduit 95.

The control means I2 is operable to start the compressor I3 thereby supplying pressure air to the pipe 21 whenever the pipe 21 becomes filled with sewage or other material to be pumped. As soon as the pressure air has efiected ejection of this material from the pipe 21, the control means is operable to stop the compressor and to vent the pipe 21 to the atmosphere thereby permitting it to refill.

The electrical circuit of the particular control means embodied in the apparatus illustrated in Figs. 1-3 is illustrated in Fig. 4. As there shown, the control means I2 includes a starting electrode 91, a stop electrode 99, a warning electrode II", and a control cabinet IE3 which is preferably water tight. The control cabinet I03 houses a main line switch I04, a starting box I for the motor I06 which drives the compressor I3, a voltage reducing transformer I01 for the control circuit, and a relay arrangement I08 for controlling the operation of the starting box I05.

The

electrodes

91, 99, and IOI in the illustrated control system are of the usual type which ineludes an elongated rod or contact electrode which extends downwardly toward the liquid level and which completes an electrical circuit through the liquid material being pumped. Each of the

electrodes

91, 99, and IQI is electrically insulated from its support. To this end, the electrodes may be mounted in the manner shown in Patent No. 2,380,651.

The starting electrode 91 is supported in the flange 41 of the pipe section 45 cf the inlet assembly 29. The electrode 91 extends downwardly from the flange 41 to a point approximately level with the uppermost point of the pipe 21 (Fig. 1) so as to complete a circuit through the sewage to ground when the sewage level rises to a point where the sewage contacts the electrode.

The warning electrode IIJI is also supported in the flange 41 of the inlet assembly and this electrode IIlI extends downwardly into the pipe 21 along side of the starting electrode 31. The warning electrode I III is somewhat shorter in length than the starting electrode and comprises a part of a warning circuit I I19 (Fig. 4) which actuates a horn I II] or other warning device in the event that the sewage rises to an undesired level in the pipe 45.

The stop electrode 39 is supported in the air trap or dome 10 in the horizontally extending pipe 69 attached to the cross fitting 55 of the outlet assembly ill. The electrode 99 extends to a point adjacent the level of the lowermost point of the receiver pipe 21 so as to provide a continuous electrical circuit until the pipe 21 is completely emptied by the pressure air. The elec-- trodes 91, 99, and HM are connected to the associated relay and other control units locatedin the control cabinet I03 by means of conductors III, I12, and I I3, respectively.

As has been pointed out, the control means for the pumping mechanism eifects the desired sequence of operation by control of the operation of the compressor I3. In this connection, the main power lines II4a, I I 4b, and I I40, are connected through the main line switch. I84 and leads. IIa-, 5b, I150 to the starting box I05.- which is in turn connected toth'e driving-motor I06 for the compressor I3 by leadsI I6a, I IGb, and H60. In the illustrated structure the-motor I06 is athree phase motor, however, it will b ob-- vious that a single phase motor may be used. if desired.

As illustrated in Fig. 4, the power for the control circuitis taken from leads II5b and H50 through the switch I II, the voltage of the power source being reduced by the voltage reducing transformer I01. One of the low voltage leads; of voltage'reducing transformer I01 is groundedas shown at H8 and the other low voltage leadiis connected to one terminal of the starterbox by means of lines H9 and 19a. Dine. II9is-a1so connected by a line 917 to one terminal of thewarning horn H0 and by a line II-Sc to oneterminal of the coil of. an induction relay I20. The other terminal of the warning horn IIO is-c1onnected by line I13 to the warning electrod I.0I. The second lead of the-coil of theinduction relay I20 is connected by means of the line M2 to the stop electrode 99 thus'pro-viding a circuit which maintains the contacts I20aof the induction re.- lay I20 in a closed condition whenever there is liquid in the lower end of the pipe 21. One of the contacts of the induction relay I20 is connected to ground through. the lead I2I and the other terminal is connected to one of the contacts I22a of a second induction relay I22 through a conductor I23. The other of the contacts I22a of the induction relay I22 is connected to one lead of the induction coil of that relay, that lead of the coil also being connected to the starting electrode 91 through the lead- I I I. The other lead from the coil of the induction re lay I22 is connected by means of a line. I24 to one of the terminals in the startingbox I05.

While the

electrodes

91, 99, and IOI intheillustrated control system are of theusual type, other. types of electrodes may be used. For example, a control system using the thermosensitive type of control electrode, such as the system soldby the General Electric Company of Schenectady, New York under the trade name Thermasul, may be used with good results; The Thermasul thermosensitive type control electrode includes a continuously heated resistance element which changes in resistance value in responseto changes in temperature, and this change in resistance is. relied upon to actuate the control relays; When thermosensitive electrodes are to beused, 'they' should be located so that they will be contacted by the liquid being, pumped as it rises :W-ithinthe" apparatus.

When placing the pumping system illustrated in Figs. 1, 2, 3, and 4 in operation,

valves

33 and 63 are opened and the main line switch I04 and the control systemswitch I I! are closed .to'energize the electrical circuit. The sewage or other material being pumped flows. past the unifiow valve M and flows into the lower end of the pipe 21. As the level of the sewage rises, the. electrode 99 is contacted by the rising liquid, and this-closes the circuit through the induction relay I20, causing the contacts l20a thereof to close. The sewage continues to flow into the pipe21 until itrises to a point where it contacts the lower end of the starting electrode 91. Atthis time, acircuit is established to ground. through the induction relay I22 causing both sets of the contacts I22a of that relay to close, thereby causingcur rent to flow to the. actuating coi'l ofthe starting preventing back flow into the inlet pipe 3. As-

soon as. the pipe 21 is entirely emptied, the level of sewage will drop below the electrode 99 and the electrical circuit through the coil of the in duction relay I20 will be broken thereby causing the contacts a of that relay to open. This stops the compressor motor I05 since the circuit throughthe electrode 9'! is broken as soon asthe upper end of the pipe 2! is cleared.

It will. be seen that during the time that the circuit through. thestart electrode 97. is opened and the circuit through the electrode 99 is closed. as the pipe 21 is being discharged, a circuit to energize the motor starter I05 is maintained through the parallel contacts I22a of the induction relay I26, the lead I23, and the contacts I20a of the relay I20.

When the compressor I3 stops, the diaphragm operated valve 93 opens and the pressure air in the pipe 2! is vented to the atmosphere through the exhaust line -9I. As soon as the air pressure in the pipe 2'! is sufficiently reduced, the sewage again flows through the unifiow valve 39 until the level of the sewage reaches the electrode 91. The pumping. cycle is then repeated.

While the equipment which has been described employs .a single pumping unit, two or more units may be disposed in. parallel to provide duplex or multiple pumping systems. If a duplex system is employed, for example, the units are arranged to fill alternately so that one unit is filling while the other unit is pumping.

The pumping unit which has been described is extremely efficient in operation and is not subject to clogging. In addition, sewage containing large amounts of suspended material may be pumped by the unit since the reducer 5.3 and the reducing elbow 51 cause high flow velocities in. the system and insure that the pipe 2'! is emptied on every cycle of the apparatus thereby preventing the building up of deposits of 'solid materials. The system is inexpensive to install since it is fabricated from standard pipe sections and may be installed in standard sized manholes. This eliminates a large number of special. parts which greatly increase the cost of construction.

The control system which has been described for use in. the foregoing unit stops the compressor and the supply of air to the pipe 2'1 when.

an electrode or other controlling member at the lower end of the pipe 21 is actuated. If it is desired to dispose all of the controls in the manhole I, a timing arrangement may be provided whereby the compressor is started and runs for apredeterm-ined period of time, which predeter mined time will be sufiicient to eject all or essentially' all of the material in the pipe 2?. At the end of the predetermined time, the timer connects the pipe 21 to the vent I5? (Fig. 5) thus enabling thev pipe to be refilled with the materialbeingipumped;

The pumping mechanism I which has been described, is adapted to. discharge the material being pumped into a line which is under pressure. The mechanism can, of course, be employed as a lift station in a gravity system, that is, it can be used merely to raise material from one level to another. However, if the system is to be used only as a lift station, it can be simplified to eliminate several parts and to dispose all of the control elements in a single manhole. A pumping system which has been modified to operate efficiently as a lift station is shown in Fig. 5. Since most of the component parts are of the same construction as similar parts described in connection with the pumping mechanism I, a detailed description of the component parts will be omitted, a detailed description being given only when the element or component part is materially changed.

The lift station illustrated in Fig. comprises a pair of spaced, standard wells or manholes I25 and I25, and a pumping mechanism I21 which is disposed in part within and which in part extends between the manholes I25 and I26. The pumping mechanism I2! includes an elongated, generally horizontally extending section of pipe I23 which is disposed between the manholes I25 and I26, the end of the pipe I28 which is disposed in the manhole I25 being connected to an inlet assembly I29 and the end of the pipe I28 which is disposed adjacent the manhole I26 being connected to an outlet assembly we. The inlet and outlet assemblies I23 and I3Il are adapted to control the flow of sewage into and out of the pipe I28. The pipe I23 is sloped downwardly from the inlet end to the outlet end between 1 inch and feet per 100 feet of pipe in the same manner as has been described in connection with the pipe 27 of the pumping mechanism I.

The inlet assembly I29 is similar to the inlet assembly 29 which has been described, and includes a shutoff valve I3I which is controllable from the ground level through a valve casing I32. One side of the valve I3I is connected to an inlet line I33 which conducts the material being pumped into the pipe I28. The other side of the valve I3I is connected to a pipe I34 which connects with one side of a uniflow or check valve I35 which prevents back flow of the material being pumped into the inlet line I33. The inlet assembly I29 also includes a flanged T-fitting I35 which connects the outlet of the unifiow valve I35 to thepipe I23 which serves as a sewage receiver and a sewage conductor for the unit. As in the case of the pipe 2'! and the fitting 43 which has been described, the T-fitting IE3 is of the reducing type in the illustrated structure. The third opening in the T-fitting I35 is upwardly directed and is connected to a short pipe section I37 which defines a vertically extending chamber, the upper end of the pipe section it? being sealed by a blind flange I38 which is provided with several apertures adapted to receive control elements of the control system and an air inlet and outlet pipeline IBQd as will be hereinafter described. In addition, the controls for the lift station include a pressure responsive electrical switch Hid, this switch being connected to the pipe I37 by a pipe I45.

' The outlet assembly I30 of the ejector unit is somewhat similar to the outlet assembly 33 which has been described except that the number of parts is reduced. The outlet assembly I30 includes a riser pipe I4I which may, as illustrated, be of reduced diameter and which is connected to a 90 elbow and a 180 elbow or return bend to an outlet line I44. The outlet line I44 is disconstruction as the reducer 53, the large-areaend of the reducer I 48 being connected to the pipe I28 and the bottom of the reducer forming a continuation of the bottom of the pipe I28. The provision of the reducing 180 elbow I47 and the reducer I48 produces high velocity flow at the outlet end of the pipe I28 which insures that solid materials are flushed from the system on every cycle of the equipment. Flow of material by gravity into the riser pipe I4I from the outlet main I44 is prevented by the provision of the elbows I42 and I43, which constitute a reverse bend whose top is higher than any point in the outlet main I44. Since the ejector unit I2! is adapted to operate as a lift station, it does not require means to prevent the flow back of a material which is under pressure.

In order to supply pressure air for the system, a motor driven air compressor I49 is provided which is similar to the air compressor I3 which has been described. The compressor I49 includes an inlet line I50 having an air filter ISI and an outlet line I52 having a check valve I53 and a safety valve I54. The compressor I49 is also provided with an auxiliary air outlet I55 which is connected to a diaphragm operated valve I55 in a vent line I5I. connected to the blind flange I38 on the pipe I3? is connected to the vent line I51 and the main outlet line I52 of the compressor. The line I3a is provided with a conventional strainer or air screen I58 in accordance with the usual practice.

The electrical control means (Fig. 6) includes a starting electrode I59, a warning electrode I80, and a pressure actuated switch I39, The contacts of the pressure actuated switch I39 are normally open, and the switch is of such design that these contacts are closed when the airpressures in the pipe I28 (which pressure is transmitted to the switch via thepipe section I31 and the pipe I45) reaches a predetermined value, the contacts opening automatically when the pressure again drops below this value. The predetermined value for setting the pressure switch is preferably somewhat above the pressure in pipe I28 when it is vented and below the pressure which is present in the pipe when the material is being ejected by air pressure.

The electrodes I59 and IE6 and the pressure switch I39 are connected by means of lines iti, I62, and I63, respectively, to the other elements of the control system which are housed within a cabinet/.154. These elements include a main line switch I85, a starting box IBE for the motor IGI which drives the compressor I49, and a volt age reducing transformer I for the control circuit. The electrodes I59 and I59 are of the in connection with those electrodes.

As shown in Fig. 6, an incoming three phase power line IBIla, I691), and IfiIlcis connectedthrough the main line switch IE5 to the starting box I66 which is in turn connected to the motor The pipeline I390; which is I61 by the lines I1IIct, I161), and I100. Power for the control circuit is drawn from the lines I69?) and I690 through lines I1I through a control power switch I12 to the voltage reducing transformer I68. One low voltage lead of the transformer I66 is grounded as shown at I13 and the other end is connected to one of the control terminals of the starting box I66 by a line I14, this same lead being connected to one of the terminals of an induction relay I16 and to one of the terminals of a horn I15 or other warning device provided in a warning circuit. To complete the warning circuit the other terminal of the horn I15 is connected to the warning electrode by line I62. The other terminal of the starting box for the compressor motor I61 is connected by means of the lines I11, the induction relay I16, the line I6I, and the starting electrode I59 to ground. The pressure operated switch I39 is connected to the induction relay I16 by the line I63 in such position that it parallels the circuit through the electrode I59.

When placing the lift station illustrated in Figs. and 6 in operation, the shutoff valves I3I and I45 are opened and the main line switch I65 and the control circuit switch I12 are closed to energize the electrical circuit. The sewage or other material being pumped flows from the inlet line I33, through the uniflow valve I35, and thence into the lower end of the pipe I28. The sewage continues to flow into the pipe I28 until it rises to a point where it contacts the lower end of the starting electrode I59. At this time, a circuit is established through the operating coil of the induction relay I16 to ground via the starting electrode I59. Operation of the induction relay I16 causes the starting box I66 to energize the motor I61 to thereby operate the compressor I49. The operation of the compressor I49 builds up air pressure within the compressor and this pressure acts through the auxiliary outlet I55 to close the diaphragm valve I56 in the vent line I51.

When the valve I56 is closed, air is forced down the pipeline I390, into the chamber formed by pipe I31 thereby forcing thesewage up through the riser pipe MI, around the elbows I43 and I42 and into the line I44 in which it flows by gravity to the next lift station or to adisposition point. As soon as the pressure builds up within the pipe I28 and the other parts of the pumping mechanism to the predetermined operating limit of the pressure actuated switch I39, that switch is closed providing a circuit to ground from the induction relay I16 which is in parallel with the circuit through the starting electrode I59 (Fig. 6). As the material being pumped is moved out of the mechanism, the level in the pipe I21- drops and contact i broken between the starting electrode I69 and the sewage, thereby breaking that circuit to ground through line -I6I and the electrode I59. When this occurs the energizing circuit for the relay I16transfers to the circuit through the pressure operated switch I39. As soon as the sewage contained in the pipe I 29 has been ejected, some of the pressure air will pass around the reducing elbow I41, through the riser pipe I4I and into the outlet main I44, this resulting in a reduction in pressure Withinthe pipe I28 to below the predetermined opening value of the switch I39. This reduction in pressure opens the pressure actuated switch I39 thereby topping the compressor and causing the diaphragm operated valve I56 to open. This vents the pipe I28 and permits sewage to again flow thereinto under the action of gravity. The cycle is repeated every time the sewage 'rises to a point where it contacts the electrode I59.

The lift station which has been described embodies various novel features which make it extremely efficient in operation and which at the same time make it relatively inexpensive to install and maintain. First, the lift system as in the case of the pumping system which has been described, may be installed in standard manholes and in addition, is fabricated entirely from standard valves and pipe sections. Further, all of the controls and operating elements are disposed in a single manhole structure so that the installation is simplified and servicing and repair is facilitated.

While the pumping station and lift station which have been described above employ an enlarged section of pipe between the two manholes of the pumping system for the dual purpose of providing a container for the material to be pumped and a conduit therefor, an equivalent capacity may be obtained from smaller pipe by disposing a plurality of pipes connected in parallel relation between the outlet and inlet of the system. Such a construction is shown in Fig. *1 Where three lengths of pipe indicated as ISO are connected in parallel to branch fittings -'I8I each of which extends from one of a pair of manholes I32 which house a pumping or lift mechanism (not shown). This arrangement of the pipe also makes possible the convenient enlargement of capacity of existing units as neededto any practical value without changing the inlet or outlet fittings. The capacity may be changed by merely digging up a single pipe between the manholes and substituting two or more pipes therefor.

In the foregoing there have been described certain pumping mechanisms and apparatus particularly adapted for use as pumping and liftstations in municipal sewage and like ystems. The disclosed apparatus is operable to pump large volumes of sewage and other materials efliciently and economically, and the apparatus embodies various important and novel concepts and structural arrangements. Included among these is the feature of sloping the section of pipe used to contain the material being pumping to the outlet end; the features of providing a reduced crosssectional area at the outlet end of the pipe section, and the use of a reduced diameter vertical pipe section at the discharge side of the apparatus; the attainment of complete control of the lift station type apparatus from a single manhole; the provision of pumping apparatus that can be installed in small diameter standard manholes and can be embodied in existing sys-- tems with a minimum of change and expense,'

eration even when the unit is completely submerged. Also, in the event that extensive pumping is needed in a given area, air main may radiate outwardly from a central air compressor and the flow of air into and out of each individual unit may be controlled by solenoid valves actuated by controls of the type which have been described In addition to being useful in providingiow cost initial installations, various of the features of the invention may be combined to convert certain gravity flow systems to pressurized systems without even requiring the removal of pipe which has already been installed. This is particularly important when it is desired to increase the capacity of a system by operating it under pressure.

Various features of the invention which are believed to be new are set forth in the appended claims.

I claim:

1. A pump comprising an underground piping system for conveying sewage and other fluids, a length of pipe and means connected into said length of pipe for locally increasing the pressure head of the fluid flowing through said pipe, said means including a pair of spaced apart underground structures positioned along said pipe the section of pipe between said underground structures sloping downwardly in the direction of flow therefrom, an inlet assembly in said pipe which includes a uniflow valve, said inlet assembly being disposed in the upstream structure, an outlet assembly in said pipe which is disposed in the other of said structures, and includes a V-bend which provides a trap disposed below the level of said pipe, a source of pressure air, a vent line, means connecting said section of pine to said source of pressure air and to said vent line, and control means operable to connect, alternately, said section of pipe to said source of pressure air and to said vent line in response to changes or the level in said section of pipe of the material being pumped.

2. A pump comprising an underground piping system for conveying sewage and other fluids, a length of pipe and means connected into said length of pipe for locally increasing the pressure head of the fluid flowing through said pipe, said means including a pair of spaced apart underground structures positioned along said pipe, the section or said pipe between the underground structures sloping downwardly from the upstream end to the downstream end, an inlet assembly in said pipe which includes a unifiow valve, said inlet assembly being disposed in the upstream structure, an outlet assembly in said pipe which includes means for preventing flow of the fluid passing through said pipe back into the section of said pipe extending between said structures and means for restricting the cross-seetional area of said pipe, said outlet assembly being disposed in the other of said structures, a source of pressure air, a vent line, conduit means connecting said pipe section to said source of p essure air and to said vent line, and control means operable to connect, alternately, said section of pipe to said source of pressure air and to said vent line in response to changes of the level in said section of pipe of the material being pumped.

3. A pump comprising an underground piping system for conveying sewage and other fluids, a length or" pipe and means connected into said length of pipe for locally increasing the pressure head of the fluid flowing through said pipe, said means including a pair of spaced apart under: ground structures positioned along said pipe, the

section of said pipe between the underground,

structurs sloping downwardly from the upstream end to the downstream end, an inlet assembly in said pipe which includes a unirlow valve, said inlet assembly being disposed in the upstream structure, an outlet assembly in said pipe which includes means for preventing flow of the fluid passing through said pipe back into the section of said pipe extending between said structures and means for restricting the cross-sectional area of said pipe, said outlet assembly being disposed in the other of said structures, a source of pressure air, a vent line, conduit means connecting said pipe section to said source of pressure air and to said vent line, and control means operable to connect, alternately, said section of pipe to said source of pressure air and to said vent line in response to changes of the level in said section of pipe of the material being pumped, said source ofpressure air, said vent line, said conduit means, and said control means being located in said upstream underground structure.

4. A pumping system comprising a source of pressure air, a vent line, an elongated pipe defining a flow channel having an inlet end and an outlet end and sloping downwardly from the inlet to the outlet end thereof, an inlet line for conducting the material to be pumped into the inlet of said pipe, an outlet line connected to the outlet of said pipe, a uniflow valve connected between the inlet of said pipe and said. inlet line for preventing the flow of material from said pipe to said inlet line, means for preventing the flow of material from said outlet line into said pipe, said pipe having a reduced diameter adjacent its outlet end, the reduction in diameter being effected by restricting the upper portions of the flow channel while maintaining a continuous downward slope along the bottom of the flow channel, conduit means connecting said pipe to said source of pressure air and to said vent line, and a control means operative to connect, alternately, said pipe to said source of pressure air and to said vent line in response to changes of the level of the material being pumped in said pipe.

5. A pumping system comprisin a source of pressure air, a vent line, an elongated pipe having an inlet end and an outlet end and sloping downwardly from the inlet to the outlet end thereof, an inlet line for conducting the material to be pumped into the inlet of said pipe, an outlet line connected to the outlet or said pipe, a uniflow valve connected between the inlet of said pipe and said inlet line for preventing the flow of material from said pipe to said inlet line, means for preventing the flow of material from said outlet line into said pipe, means for restricting the cross-sectional area of said pipe adjacent its outlet end to cause high flow velocities at its outlet end, a trap intermediate said outlet end of said pipe and said outlet line, conduit means connecting said pipe to said source of pressure air and to said vent line, and a control means operative to connect, alternately, said pipe to said source or" pressure air and to said vent line in response to changes of the level of the material being pumped in said pipe.

6. A pumpin system comprising a source of pressure air, a vent line, an elongated pipe having an inlet end and an outlet end and sloping downwardly from the inlet to the outlet end thereof, an inlet line for conducting the material to be pumped into the inlet of said pipe, an outlet line connected to the outlet of said pipe, a unifiow valve connected between the inlet of said pipe and said inlet line for preventing the flow of material from said pipe to said inlet line, means for preventing the flow of material from said outlet line into said pipe, a U-bend which forms a trap intermediate said outlet line and 15 said pipe, means for restricting the cross-sec.- tional area of said pipe adjacent its outlet. end including a reducer intermediate said U-bendand said pipe, the lowermost surface of said reducer sloping downwardly from said pipe'to said U- bend, conduitmeans connecting said pipeto. said source of pressure air and to vsaid vent. line, and a control means operative to connect,xalternately, said pipe to said source of pressure air and to said vent line in response to changes of the level of the material being pumped in said pipe.

7.. A pumpin system comprising, a source of pressure air, a vent line, an elongated pipe having an inlet end and an outlet end and sloping downwardly from the inlet. to the outlet .end thereof, an inlet line for conducting the material to be pumped into the inlet of said pipe, :an outlet line connected to the outlet of said pipe, a uniflow valve connected between the inlet. of said pipe and said inlet line for preventing. the flowof material from said pipe to said inlet line, means, for preventing the flow of material from said outletline into said pipe, conduit meansconnecting the inlet end of said pipe to said source .of pressure air and to said vent line, and a control means operative to connect, alternately, said'pipe to said source or pressure air and to said vent line in response to changes .of the level in said pipe of the material being pumped, said control means including a control element at the inlet of said pipe which is operable toconnect said pipe to said source of pressure air when thelevel of said material rises to a predetermined level, and means which is operable when said pipe is emptied to disconnect said pipe from said source of pressure air and to connect said pipe to said vent line.

8. A pumping system comprising, a source of pressure air, a vent line, an elongated pipe having an inlet end and an outlet end and sloping downwardly from the inlet to the outlet end thereof, an inlet line for conducting the material to be pumpedinto the inlet of said vpipe, an outlet line connected to the outlet of said pipe, a uniflow valve connected between the inlet ofsaid pipe and said inlet line for preventing the flow of material from said pipe to. said inlet line, means for preventing the flow of material from said outlet line into said pipe, conduit means connecting the inlet end of said :pipe tosaid source of pressure air and to said vent line, and a control means operative to connect, alternately, said pipe tosaid source of pressure air and to said vent line in response to changes of the level in said pipe or" the material being pumped, said-control means including a control electrode at the inlet end of said pipe which is operable to connect said pipe to said source of pressure air and to disconnect said pipefrom said vent line when said material being pumped rises to a predetermined level, and a control electrode at the outlet end of said pipe which is operableito disconnect said pipe from said source of pressure air and to connect said pipetto said vent line when the level of the liquiddrops to below a'predetermined level.

9. A pumping system comprising, a source of pressure air, a vent line, an elongated pipe'having an inlet end and .an outlet .end and sloping downwardly from the inlet :to the outlet end thereof, an inlet line for conducting the material to be pumped into the inlet of saidpipe, an outlet line connected to the outlet of said pipe, a uniflow valve connected between the inlet of said pipe and said inlet line for preventing the flow of material from said pipe. to said inlet line, meansfor preventing the flow of material from said .outlet line into said pipe, conduit means connecting the inlet of said pipe'to said source of pressure .air and to said vent line, and control means operable to connect, alternately, said pipe to said :source of pressure air and to said vent line in response to changes of the level in said pipe .of the material being pumped, said control means including a control element which is operable to connect said pipe to said source of pressure air and to disconnect said pipe from said vent line when said material rises to a predetermined level to initiate a pumping operation, and means which is operable a predetermined time after :the pumping operation is initiated to connect said pipe to said vent line and to disconnect said pipe from said source of pressure air.

'10. A pump comprising, a source of pressure air, a vent line, an elongated pipe having an inlet end and an outlet end and sloping downwardly from the inlet to the outlet end thereof, an inlet line for conducting the material to be pumped into the inlet of said pipe, an outlet line which is elevated with respect to said inlet line connected to the outlet of said pipe, a uniflow valve connected between the inlet of said pipe and said inlet line for preventing the flow of material from said pipe to said inlet line, means for preventing the gravity flow of material from said outlet line into said pipe, conduit means connecting the inlet end of said pipe to said source of pressure air and to said vent line, and a control means operative to connect, alternately, said pipe to said source of pressure air and to said vent line in response to changes of the level in said pipe of the material being pumped, said control means including a control element at the inlet of said pipe which is operable to connect said pipe to said source of pressure air when the level of said material rises to a predetermined level, and means communicating with said pipe which is operable in response to a drop in air pressure from a predetermined maximum to disconnect said pipe from said source of pressure air and to connect said pipe to said vent line.

11. A pump comprising, a source of pressure air, a vent line, an elongated pipe having an inlet end and an outlet end and sloping downwardly from the inlet to the outlet end thereof, an inlet line for conducting the material to be pumped into the inlet of said pipe, an outlet line which is elevated with respect to said inlet line connected to the outlet of said pipe, a uniflow valve connected between the inlet of saidv pipe and said inlet line for preventing the flow of material from said pipe to said inlet line, means for preventing the gravity flow of material from said outlet line into said pipe, conduit means connecting the inlet end of said pipe to said source of pressure air and to said vent line, and a control means operative to connect, alternately, said pipe to said source of pressure air and to said vent line in response to changes of the level in said pipe of the material being pumped, said control means including a control element at the inlet of said pipe which is operabl to connect said pipe to said source of pressure air when the level of said material rises to a predetermined level, and means including a pressure responsive electrical switch connected to said pipe which is operable to disconnect said pipe from said source of pressure air and to connect said pipe to said vent line when the air pressure in said pipe drops below a predetermined maximum value.

12. A pump comprising, a source of pressure air, a vent line, an elongated pipe having an inlet end and an outlet end and sloping downwardly from the inlet to the outlet end thereof, an inlet line for conducting the material to be pumped into the inlet of said pipe, an outlet line which is elevated with respect to said inlet line connected to the outlet of said pipe, a uniflow valve connected between the inlet of said pipe and said inlet line for preventing the flow of material from said pipe to said inlet line, means for preventing the gravity flow of material from said outlet line into said pipe, conduit means connecting the inlet end of said pipe to said source of pressure air and to said vent line, and a control means operative to connect, alternately, said pipe to said source of pressure air and to said vent line in response to changes of the level in said pipe of the material being pumped, said control means including a control electrod at the inlet of said pipe which is operable to connect said pipe to said source of pressure air when the level of said material rises to a predetermined level, and means including a pressure responsive electrical switch connected to said pipe at the inlet end thereof which is operable to disconnect said pipe from said source of pressure air and to connect said pipe to said vent line when the air pressure in said pipe drops below a predetermined maximum value.

13. A pump comprising a length of pipe and means connected to said length of pipe for locally increasing the pressure head of th fluid flowing into and out of said length of pipe, said means including an inlet assembly, which includes a uniflow valve connected to admit the material to be pumped to said pipe length, an outlet assembly, also connected to said pipe length, which includes means for preventing back flow of the fluid pumped from said pipe length, said pipe length sloping downwardly in the direction of said outlet assembly, said outlet assembly additionally including a U-shaped conduit section which provides a trap disposed below the level of said pipe length and a conduit section of reduced cross-sectional area for increasing the velocity of flow in the region of said outlet assembly, a source of pressure air, a vent line, conduit means connecting said length of pipe to said source of pressure air and to said vent line, and control means operable to connect, alternately, said length of pipe to said source of pressure air and to said vent line in response to changes in the level in said length of pipe of the material being pumped.

14. A pumping system comprising a source of pressure air, a vent line, a length of pipe which serves as a receiver during the pumping operation, an inflow line. and an outflow line, conduit means connecting said pipe to said inflow line and to said outflow line, means for preventing the flow of material from said pipe into said inflow line, means for preventing the flow of material from said outflow line backwardly into said pipe, a trap in said conduit means located between said pipe and said outflow line and disposed below the level of said pipe, said pipe sloping downwardly in the direction of said trap, con- 7 duit means connecting said pip to said source of pressure air and to said vent line, and control means operable to connect, alternately, said pipe to said source of pressure air and to said vent line in response to changes in the level in said pipe of the material being pumped.

15. A pumping system comprising a pipe section which serves as a receiver during the pumping operation, an inflow line and an outflow line, conduit means connecting said pipe section to said inflow line and to said outflow line, said conduit means including a trap and a high velocity flow section of reduced cross sectional area intermediate said pipe section and said outflow line, said pipe section being inclined downwardly toward said trap, means for preventing the flow of material from said pipe section to said inflow line, a source of pressure air, a vent line, conduit means connecting said pipe section to said source of pressure air and to said vent line, and a control means operative to connect alternately, said pipe to said source of pressure air and to said vent line in response to changes in the level in said pipe section of the material being pumped.

16. A pumping system comprising a pipe section which serves as a receiver during the pumping operation, said pipe section having an inlet and an outlet and sloping downwardly in the direction of said outlet, an inlet line for conducting the material to be pumped into the inlet of said pipe, means for preventing the flow of material from said pipe to said inlet line, an outlet line connected to the outlet of said pipe, conduit means including a trap and a section of reduced cross sectional area disposed between said pipe section and said outlet line with said trap located below the level of said pipe, a source of pressure air, a vent line, conduit means connecting said pipe to said source of air pressure and to vent line, and a control means operative to connect, alternately, said pipe to said source of air pressure and to said vent line in response to changes in the level in said pipe of the material being pumped.

17. A pump comprising a length of pipe and means connected into said length of pipe for locally increasing the pressure head of the fluid flowing into and out of said pipe, said means including an inlet assembly which is disposed at the inflow end of said pip and which includes a uniflow valve, an outlet assembly which is disposed at the outflow end of said pipe and which includes a U-bend arranged to provide a trap disposed below the level of said pipe, said pipe sloping downwardly in the direction of flow therethrough, a source of pressure air, a vent line, means connecting said section of pipe to said source of pressure air and to said vent line, and control means operable to connect, alternately, said section of pipe to said source of pressure air and to said vent line in response to changes of the level in said section of pipe of the material being pumped.

JOE WILLIAMSON, JR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 473,591 Reilly Apr. 26, 1892 1,274,332 Rogers July 30, 1918 1,501,040 Cox July 15, 1924 1,779,319 Jennings Oct. 21, 1930