US2836122A

US2836122A - Sludge pumping assembly

Info

Publication number: US2836122A
Application number: US394264A
Authority: US
Inventors: Johnson Carl Roy
Original assignee: Yeomans Brothers Co
Current assignee: Yeomans Brothers Co
Priority date: 1953-11-25
Filing date: 1953-11-25
Publication date: 1958-05-27
Anticipated expiration: 1975-05-27

Description

May 27, 1 c. R. JOHNSON swncs PUMPING ASSEMBLY 2 Sheets-Sheet 2 Filed Nov. 25, 1953 swoon PUMPING ASSEMBLY Carl Roy lohnson, Chicago, 111., assignor to Yeomans Brothers Company, Melrose Park, I1l., a corporation of Delaware Application November 25, 1953, Serial No. 394,264

2 Claims. ((11. 103-45) The present invention is directed to an improved apparatus for handling materials such as sludge and industrial wastes of different natures which are difficult to pump efiiciently.

Numerous difierent arrangements are currently in use for the purpose of pumping sludge suspensions at various concentrations. Each has its own advantages and its disadvantages. From the standpoint of operating efficiency, one of the best of these arrangements is a pneumatic ejector of the type which consists of a closed receiver provided with check valves on the inlet and in the discharge lines, a control valve mounted on the receiver and a pair of open bells suspended in the receiver and movable in response to the liquid level in the receiver to operate the control valve. The control valve, in turn, actuates a piston valve which operates to introduce and to terminate the flow of compressed air into the receiver during the discharge cycle.

This type of pneumatic ejector is very efiicient in operation and requires little maintenance. However, the unit is expensive to install and is somewhat expensive to operate because of the necessity of providing high pressure air. Moreover, ejectors of this type operate by a gravity feed and must be located so that the inlet to the ejector is lower than the discharge point for the sludge being received. Normally, this necessitates providing a special chamber or other enclosing structure located below the floor level of the building in which the ejector unit is installed. Such enclosures add materially to the cost of the installation and makes the unit relatively inaccessible for purposes of lubrication and whatever maintenance that may be required.

In strictly mechanical systems for handling sludges, it is common to employ positive displacement sludge pumps of the plunger type in which the fluid is pumped by the reciprocating action of a piston type plunger. Normally, the pistons of such pumps are driven by means of an eccentric connected to a positively driven shaft. The drive means and the eccentric are coupled together by means of a shear pin which provides some degree of protection against excessive stresses in the drive mechanism. Pumps of this type are essentially constant speed mechanisms, with only the stroke of the plunger being capable of adjustment and that to only a limited extent. Further, when the plunger displacement is to be changed it requires shutting down the pump and realigning the eccentric with respect to the driven shaft. This procedure is, of course, time consuming and incapable of fine adjustment of the stroke of the plunger except by continuous trial and error.

An even more serious objection to the eccentric drive, plunger type sludge pump arises from the fact that the motion of the plunger is not strictly an up and down motion but has a lateral component which creates excessive wear on the packing of the cylinder. Additionally, these pumps are subject to considerable vibration during use, as a result of the reciprocation of the plunger, and

head 27. Thus, as the plunger reaches theupper end Patented May 27, 1958 ice pumps do not completely satisfy the requirements of the art, and there is a continuing need for an improved pump mechanism for handling sludge and sludge type materials which is efficient in operation and inexpensive to maintain and to install. The provision of such a pump mechanism is the principal object of the present invention.

Another object of the invention is to provide an improved pump mechanism particularly adaptable to handling sludge and sludge type products under such conditions that the rate of discharge of the pump can be readily and continuously varied during the operation of the pump, without shutting down the unit.

Still another object of the invention is to provide a drive mechanism for sludge pumps which eliminates the numerous gear assemblies of existing drive units and thereby eliminates the objectionable noise and relatively high expense of such gear assemblies.

An illustrative embodiment of the invention is illustrated in the accompanying drawings where:

Figure 1 is a somewhat schematic view in elevation of a complete pump mechanism in accordance with the invention, and

Figure 2 is an enlarged View in elevation and partly in cross section illustrating certain natures of the pump mechanism shown more fully in Figure 1.

The pump mechanism illustrated in Figures 1 and 2 includes a pump cylinder or receiver generally indicated at numeral 10 in which a plunger 11 is arranged to reciprocate. The cylinder 10 is relieved to accommodate a. stufling box gland 12 and a plurality of packing rings 13 (Figure 2).

The sludge or other material to be pumped is introduced into the mechanism through an inlet line 14, the flow through the line 14 being governed by a ball valve element 16 arranged to be seated on a removable valve seat ring 17. On the upstroke of the plunger the sludge entering the inlet line 14 unseats the ball element 16 and passes into the pumping chamber 18 where on the downstroke it is acted upon by the reci rocatory movement of the plunger 11. The sludge then under pressure is forced through an outlet line 19, and unseats the outlet valve member 20 which normally rests in seated relation on a removable valve seat ring 21. The inflow valve is, of course, closed at this time. The pumped sludge is conducted away from the pump mechanism through an outlet line 22;

The plunger, in the illustrated mechanism, has a gen erally hollow interior and is provided with a centrally disposed cylindrical shaft 23. The upper end of the shaft 23 is received within a fluid tight casing 24 and has a piston head 27 arranged to move in the casing 24 in response to fluid pressure in the casing 24. in the position of the mechanism shown in Figure 2, the plunger 11 is at the bottom of its stroke and is arranged to move upwardly upon the introduction of a pressure fluid such as oil into an inlet conduit 28 which communicates with the casing 24. As the hydraulic fluid under pressure is introduced into the conduit 28, it acts against the piston head 27 on the shaft 23 and forces the piston and hence the plunger 11 upwardly.

A second conduit 2? is connected to the casing 24 at a point above the limit of travel of the piston head 27, and like the conduit 28 is designed to admit hydraulic fluid to the casing 24- or to convey fluid from that casing depending on the direction of movement of the piston 'voir 34. p a As shown in Figure 1, the'port46 of'the reversing valve 40 is connected to the'line 2S? o f'the hydraulic rarnasslembly and th e'port 47 is connected to the line 28. Hence, by operation of the reversing valve, fluid is alternately V p 3. of its stroke, hydraulic fluid is V duit 29 and simultaneously drained from the conduit 28'so that the fluid acting from the top of the piston head 27 causes the plunger to reverse its direction and commence its downwardls'trolte Similarly, in theupward stroke, when fluid is being introduced into the conduit 28, the fluid remaining in the casing 24 is being drained through the conduit 29 by 'a control system subsequently to be described. The casing 24 and the piston head 2'7, thereby provide a hydraulic ram mechaintroduced into the counisjrn for controlling the reciprocating movement or" the discharge line 32 forthe-purpose of preventing the pressur'e'in the line from reaching too high a value. If the pressure is below a certain predetermined safe value, the fluid passes directly through the relief valve 35, but if the pressure exceeds the predetermined value, at least To obtain the fullest realization of the advantages of some of the fluid is shunted back into the reservoir 34 7 through a line 37. The discharge line 32 is in continu ous fluid cornmunication by Way oi line 38, with an inlet 39' of a reversing valve 49, and also with a port'41 on atwo-way pilot valve 42 1 The reversing valve 40 may consist of a casing in which a sliding plunger with ports provided therein is free toslide in response to changes i'n'fiuidpressu're at opposite. ends of the slide. drawings; the reversing valve has a pair of oppositely spaced ports 43' and 44 which receive the hydraulic fluid to act againstene .or the other end of the slide contained in the casing, and a pair of outlet ports 46 and 47 which alternately cornmuriicatejwith the inlet port 39 throughthe ports in the slide, depending upon'the position of the slide in the reversing valve casing. Another outlet or exhaust port 43 is provided along with a conduit 49m drain fluid from whichever port 46 or 7- is not being supplied introduced "underpressure into the line ,28 from the port-47 to move the plunger 11' upwardly, and in the next half cycle, the pressure fluid is introduced through the line29 into the port 46 to reverse the movementof the plunger 11.

t The operation of the reversing valve 40is controlled by the pilot valve 42 which determines'into which end-of the valve 40 the hydraulic fluid is introduced. The pilotvalve 42 includes four ports, the first of which, '41, is

in constant fluid communication with the pump 31. A'

second port 51 and an associated conduit 52 serve to. drain the hydraulic fluid from the pilot, valve'bac'k into; the reservoir. 34 as indicated-by the arrows. A,-pair of ports 53 and 54 are, alternately connected through the valve to theinlet port 41 and function to introduce the reversing valve 40. v 7

Therate of deceleration or acceleration at the ends (Sf the plunger stroke are very conveniently controlled by providing a pair of adjustable speed control throttling the hydraulic'fluid. alternately into ports 4:3 or 44 of 'va1vesf56 and 5-7 in the, lines 58 andf 5 9 whieh' connect the ports 54, and 53. with the

ports

44 and 43, respective 71y, tofregulate the an ountof hydraulic fluid entering the reversin'g'valve 40'fro mithe 'pilot'valve42.

in; the type of valve shown in "the with the pressurefluid back into the reser- The speed of the plunger is governed by the setting on a bypass valve 61 located in the line 62 which con meets the discharge line 32 to the reservoir 34. The position of the valve 61 is adjustable to vary the amount of fluid available to actuate the hydraulic. control system by returning continuously predetermined amounts of the fluid back to the reservoir. By this means a uniform output pump 31 can be used to drive the sludge pump at varying speeds.

The pilot valve 42 is operated by a ii-shaped control member 63 which is arranged to be engaged by an operating dog 64 carried on a shaft 66. of the control member 63 from: one position 'to its other position changes the flow of fluid through the pilot valve 42 in the manner previously'described', to thereby control the operation of the reversing valve 40.;

In the drawings, the plunger ll is shown in its lower-V most position. As'the plungermoves. into this position, the pilot valve 42 is moved to cause the oilor other hydraulic fluid to pass from the port 41' into the port 54, 7 through the valve'56, and into the'port 44 of the reversing valve 40. When this happens, the pressure'at the end'of the slide contained in the reversing valvef40 causes, the slide to move from right to left. As theslide shiits,

it establishes communication between the inlet line 38 I and the port 47 to introduce fluid underrpressure into thelower end of the hydraulic ram assembly. and thereby force the piston'hejad 27 upwardly. At the'sanie time the postiofln' of'th'e, pilot valve 4211is such that the por t 5 3 is open to the drain port 51 so that fluid fromgthe' opposite end of the reversing valve 4% at the port 43,

can drain back into the reservoir 34 through the con;

duit 52; .In this position, the drain port 48 of the reversing valve is open to port 46' of the same valve thereby permitting "the hydraulic fluid from the upper part of; the hydraulic ram to be drained" through the line 29 and the line 49 back into the-reservoir 34; 7

As the plunger 11 approaches the upper end of its stroke. the dog 64* engages the control member. 63"a.n'd

movesit't'o theidotted. line position shown in Figure 1. In

' this position-off the valve, thepo'rt 4?; is in communifcation with port5'3so that fluid under pressure is introduced throughth'e valve 57 int o'the port 43 and into the reversingvalye ,dllfThe slide of thereversing valve'40 then shifts to the right in response to this change in pressurev and the inlet line 38 is then connected throughtheslide i with theport 46 and 'theline 29. At the same time,

the drain port 48 is;inr fluid communication with the port 47 s'o tha't as 'thehydraulic fluid exerts its pressure onth'e top of the piston head 2 7{the hydraulic fluid at the base of the hydraulicramis drained through the line 28 and, the line 49 back into the reservoir 34. Similarly, in this- 'po sition the-port"54 of thepilot' valve I 42 is connected to the drain port 51 so that hydraulic fluid is drained-fromthe port 440i the reversing'valve assembly.

Thiscompletes thecycle offoper'ation. V The. present invention provides a very convenient means for adjusting boththestroke andspeed of plunger-1 type"punipsin a manner not: previously possible with conventional sludgepu-mps; One of the important'advantagesofthe-assembly is' the fact that the plunger is operated inastrictly'up and downmotion Without substantial' "side thruston the'plunger elements whichfwou-ldcreate'undu'e'wear on the-packing. This absence of lateralz thrust caused byi'the. plunger movement is also responsibleforthe substantial decrease in mechanical vibration.'accomPl ished by pumps of the present invention. V j V r The capability'of thepresent assembly to be accurately adjusted; over aywide speed-range makes it preferable to other; types of; pumps, eyenjthose employing an ex-. pensive variable speed drive because the means for ary n he p d n he p e en emb y s c dera ly simpler and less cap'able of mechanical damage. V F It will be evident that; various modifications can madetd the structure of the above-described assembly The movement 2,8 without departing from the scope of the present invention.

I claim:

1. A sludge pumping system comprising a receiver including an inlet, an outlet, and a plunger slidable within said receiver to eflect an intake of material through said inlet and a discharge of such material through said outlet, a ram or" the double acting type including a cylinder, a piston slidable within said cylinder, and a piston rod extending from said cylinder and inter-connected with said plunger, a constant delivery fluid pump, a reservoir supplying fluid to said pump, and means for adjustably controlling the operation of said plunger including a pressure relief valve, a by-pass valve, a reversing valve, a pilot valve, a pair of flow regulating valves, and means associated with said plunger for actuating said pilot valve and for controlling the length of stroke of said plunger, said reversing valve having individual communication with said pump, said reservoir, and with each of the ends of said piston whereby a first pressure fluid flow may be alternately directed from said pump through said reversing valve to one end and then to the other end of said piston and whereby a simultaneous withdrawal of pressure fluid may be afforded from the opposing end of said piston through said reversing valve to said reservoir, said by-pass valve and said pressure relief valve being intermediate of said pump and said reversing valve whereby the speed of the stroke of said plunger may be controlled and whereby overload protection may be secured, said pilot valve having individual communication with said pump, said reservoir, and with each of the ends of said reversing valve whereby, through cooperation of said pilot valve actuating means, a second pressure fluid flow is alternately directed from said pump through said pilot valve to one end and then to the other end of said reversing valve and a simultaneous withdrawal of pressure fluid is afforded from the opposing end of said reversing valve through said pilot valve to said reservoir, said second pressure fluid flow and said simultaneous withdrawal of pressure fluid from said reversing valve eflecting reciprocation of said plunger by causing said first pressure fluid flow to be alternately directed to one end and then the other of said piston and by affording simultaneous withdrawal of pressure fluid from the opposing end of said piston, said second pressure fluid flow and said withdrawal of pressure fluid between said pilot valve and said reversing valve each being through said flow regulating valves for cushioning the ends of the stroke of said plunger by controlling the acceleration and deceleration thereof.

2. A motor means including a ram of the double acting type, a pressure source, and means for controlling the operation of said ram, said ram comprising a cylinder,

a piston slidable within said cylinder, and a piston rod extending from said cylinder, said control means comprising a by-pass valve, a pressure relief valve, a revers ing valve, a pilot valve, a pair of flow regulation valves, and means associated with said piston rod for actuating said pilot valve and for controlling the length of the stroke of said piston, said reversing valve having individual communication with said pressure source, said reservoir, and with each of the ends of said piston Whereby a first pressure fluid, flow may be alternately directed from said pressure source through said reversing valve to one end and then to the other end of said piston and whereby a simultaneous withdrawal of pressure fluid may be afforded from the opposing end of said piston through said reversing valve to said reservoir, said by-pass valve and said pressure relief valve being intermediate of said pressure source and said reversing valve whereby the speed of the stroke of said piston may be controlled and whereby overload protection may be secured, said pilot valve having individual communication with said pressure source, said reservoir, and with each of the ends of said reversing valve, whereby, through cooperation of said pilot valve actuating means, a second pressure fluid flow is alternately directed from said pressure source through said pilot valve to one end and then to the other end of said reversing valve and a simultaneous withdrawal of pressure fluid is afforded from the opposing end of said reversing valve through said pilot valve to said reservoir, said second pressure fluid flow and said simultaneous withdrawal of pressure fluid from said reversing valve eflecting reciprocation of said piston by causing said first pressure fluid flow to be alternately directed to one end and then to the other end of said piston and by affording simultaneous withdrawal of pressure fluid from the opposing end of said piston, said second pressure fluid flow and said Withdrawal of pressure fluid between said pilot valve and said reversing valve each being through said flow regulating valves for cushioning the ends of the stroke of said piston by controlling the acceleration and deceleration thereof.

References Cited in the file of this patent UNITED STATES PATENTS 968,263 Quinn Aug. 23, 1910 1,910,766 Hobson May 23, 1933 2,056,204 Noack Oct. 4, 1936 2,168,711 Kyle Aug. 8, 1939 2,236,665 Beers Apr. 1, 1941 2,304,131 Vickers Dec. 8, 1942 2,363,389 Brice Nov. 21, 1944 2,413,029 McFarland Dec. 24, 1946 2,414,979 Ross Jan. 28, 1947 swim) STATES PATENT ()FFICE CERTIFICATE 0F CGRRECTION Patent No. 2,836,122 May 27, 1958 Carl Roy Johnson It is hereby certified that error appears in the printed specificatio of the above numbered patent requiring correction and that the said Letter Patent should read as corrected below.

Column 4, line 16, after "reversing valve 40.," insert the following paragraph:

The shaft 66 in turn is secured to the inside of the hollow plunger 11 as best illustrated in Figure 2 of the drawings. The actuating mechanism shown in the drawings is a simple example of the types of mechanisms which can be employed to accomplish the same purpose, The mechanism can be replaced, for example, by a pair of limit switches which are actuated by the movement of the plunger and which can be used to operate a solenoid to shift the control member 63 from one position to the other. Numerous other mechanisms for accomplishing this function will suggest themselves to those skilled in the art The particular actuating mechanism illustrated in the drawings has the advantage that the stroke of the plunger may be very simply adjusted merely by positioning the dog 64 at the desired location along the shaft 66.

Signed and sealed this 21st day of October 1958,

(SEAL) Attest:

B f AXLINE ROBERT 0., WATSON Attestlng Officer Cbn'missioner of Patents