US2445205A - Pumping device for liquids - Google Patents

Description

July 13, 1948.

L. BURN PUMPING DEVICE FOR LIQUIDS Filed June 20, 1944 3 Sheets-Sh eet 1 CB a Inventor M1'Dm Attorneys July 13, 1948. L. BURN PUMPING DEVICE FOR LIQUIDS 3 Sheets-Sheet 2 Filed June 20, 1944 Inventor M July 13, BURN PUMPING DEVICE FOR LIQUIDS I5 Sheets-Sheet 3 Filed June 20, 1944 HH llllHHlHlHllHHHH Inventor A ttorneyi Patented July 13, 1948 PUMPING DEVICE FORLIQUIDS Lewis Burn, London, England Application June 20, 1944, Serial No. 541,226

In Great Britain November 6, 1942 (or. 10344) 5 Claims.

This invention relates to improvements in pumping devices for liquids, and is pertinent to intermittent pressure pumps, e. g., of the type wherein a piston is driven by a connecting rod from a crank pin or equivalent, the horizontal component of movement of the crank pin imparting cyclic variation in the velocity of the piston. In one cycle therefore two maxima are created in velocity, and kinetic energyv is imparted to the fluid pumped due to the uneven volume per unit of length of piston stroke. It is known that this energy can be stored and drawn upon for increasing the efliciency of the pump. Thus a long length of water filled pipe can usefully absorb the pulsating energy imparted thereto; this pulsating effect being in evidence at the foot suction or entry valve tends to induce a volume greater than the swept volume of the piston in the pump cylinder, creating a high volumetric efiiciency of the pumping system.

The object of the present invention is to increase the efiiciencyand range of usefulness of such liquid pumping devices, whereby relatively high speed intermittent pressure pumps may be employed, and a single pumping unit used in a pumping installation, for several differing liquids, wherein each separate body of liquid is pumped from depth and given without any risk of contamination with another liquid.

The invention consists in a system of intermittent pressure pumping wherein in combination with a pump there is provided an externally controlled but otherwise resilient piston mobile in a fluid receiving chamber or cylinder, said chamber being mounted in the energised fluid conduit, the volume ofthe receiving chamber being at least equal to or greater than the swept volume of the pump, the capacity oi said chamber being adjustable at will from maximum to nil.

The invention further consists in the provision of a spring loaded plunger mounted in the .in-' termittent pressure conduit of the pump which is reactive to pump impulses, and which is employed to actuate secondary systems of pumping. Several of these spring loaded plungersv may be employed from a single pump conduit circuit, each plunger capable pumping system for the raising of separate liquids and they may operate simultaneously for such purpose. In such. multiple pumping circuits it is essential to provide a safeguard on' the pumping system to provide against excess of pressure should the secondary systems be closed an elevated head of operating a separate,

andthe. primary pump at' work, and; for such purpose a further .type of spring loaded plunger" is provided in a primary pumping conduit, which; operates as a safety valve, and whose spring is loaded to a greater pressure than that pertinentto the impulse plungers which actuate'the sea ondary pumping systems. In regard to the externally controlled resilient piston operating to adjust the volume of fluid pumped, and assuming all delivery openings from the pump outlet are closed, the liquid in duced by suction is fed on the delivery stroke to the receiving cylinder or chamber and. the following suction stroke merely empties the said chamber.

It follows that if a common suction and de"- livery pipe be used and valve-controlled, andthe reception volume of the adjustable receiving chamber reduced, the pumping system will start to operate and willb'e at maximum when the auxiliary receiving chamber is closed. For the. sake of distinction the suction pipe is that'conduit between the pump inlet and the ioot'valve,f and the delivery pipe the ascending c'o'nduit on" the opposite side ofthe pump.' No other valves are required, and the liquid is raised in the delivery pipe by admission through the foot valve and by reason of its acquired velocity'in each pump pulsation. In contradistinction to normal pumping systems the delivery pipe is better 'ifoi the same or less diameter than the suction pipe, and that in one form of the invention the longer the delivery pipe the better, since the mass of liquid will receive each pulsation and act over each pump stroke as an energy reservoir. Thus," it is immaterial whether the pump is situate between the inlet and delivery pipes,fso long as a pulsating pressure is applied to the liquid at the junction of the inlet and delivery pipes; For such reason it is not necessary that the liquid; pumped is the same liquid that contacts with the piston, and thus with a single pump pulsation system which may be called the primary system, other secondary pumping systems may' be interposed in the pulsating liquid circuit, each having its separate suction and delivery and without the contents of, any of the energising; system admixing with the contents of anyi oi the secondary systems. These secondary pump-" ing systems are achieved by placingin the pump circuit of the primary system a spring-loaded plunger operating as a piston in a cylinder, and whilst maintained proof to fluid leakage, synchronises in movement with the pulsations of the primary circuit, and passes them on to the secondary systems. Such secondary systems are isolated from the primary system by a stop valve, and assuming the primary system to be at work, any secondary system can be made to operate by opening the stop valve, the closing, according to the capacity of the secondary system or systems, the liquid-receiving chamber in the primary suctionleg.

The spring-loaded plunger consists of a truly turned cylindrical barrel having a piston that is cup packed with a reverse placed cup at a convenient point in the plunger length; intermediate piston rings may be used, or'the plunger stem provided with a series of turned rings acting as fluid traps. A spring is disposed between the top of the plunger and the innerpart of the cylinder casing, whose strength against collapse is at least equal to the pressure in the primary pumping system.

It is of importance that the spring-loaded plunger be of light weight when the. primary system operates at high speed, such as may be available from some type of rotary vane pump, and it is-of consequence that the inertia oftthe moving parts and the column of liquid raised are proportioned toaccord with the numberofpump strokes and duty in any time interval.

In one form of the invention the foot valve may be attached-to-thefoot of the casing of the spring-loaded plunger and the pumping intermittent pressure line above the plunger, the delivery pipe being interposed above the foot valve and the underside of the said plunger. In some installations it may be convenient for the primary pumping system to be a closed system working with oilhavin a drowned suction so that the primary pump and secondary system loadedplungerscan reciprocate with the minimum of friction.

In order that the invention may be more fully understood reference isma'de to the accompanying drawings wherein an embodiment of the invention is illustrated and wherein- Fig. .1 is a diagrammatic elevation of the pumping arrangementsfor a'single liquid.

*Fig. 2 is a like view as Fig. 1, but showing the arrangementof parts for pumping one, or several. differ en t liquids.

.Fig. 3 shows detail of hand volume controlled liquid -receiving chamber and detail of spring loaded plunger.

.Fig. .4 shows .detail of spring loaded plunger and foot valve as. a combined unit.

Fig. .5 shows .detail in respect to bore hole pumpingarrangement.

Referring to the drawings and to Figs. 1 and 2 .the pump A of the intermittentpressure type is mounted in the conduit circuit between the intakeand delivery points. No pump valves are required, the working 'face of the piston being open to the liquid column, see 'Fig. 3. Preferablypos'itioned opposite the pump A is the volume externally-controlled liquid receiving chambenfhereinafter termed the volume control B, the suction pipe is shown at C, the delivery pipe D,v the foot valvefE and the spring loaded plunger. pertinent to all secondary pumping systems F, andthe. spring loaded plunger for like secondary systems G. H is the intermittent pressure line for secondary pumping.

Referring to Fig. 3 the pump A may be of any suitable type provided it produces intermittent pressure. upon thefiuid pumped. The said pump A may, as shown,

be aligned with the volume con-' trol device B, the suction leg C and delivery pipe D entering a space between the respective pistons of these two parts. The volume control device B consists of a piston I having cup leathers 2, said piston being flanged as at 3 to form a limiting stop against the face of the recess 4 of cylinder 5. Within the skirt of piston I is placed a spring B'Which reacts between the inner crown of piston I and an adjustable abutment I, the latter threaded as at -8 into the cap 9 of cylinder 5. The cap 9 is provided with vents Ill. The ad- J'ustable abutment I is centrally cored and screw I threaded andreceives the threaded control shaft 'I I, said shaft II having a hand wheel I2 or like actuating device for rotation, and an abutment face '13 adapted-to contact with a like face I4 on the'shank I5 of the headed piston packing plate I6. It will be seen from the above that the piston I if unrestrained and within the limitations imposed between the. abutments I3 and I4 and piston flange 3 and abutment 4 is free to move and is'normally urged forward to its limit position by spring 6.v 'Since however the device is in the fluid impulse circuit it is susceptible to intermittent pressure, and if the pump is running and no delivery required the abutment shaft is withdrawn and the volume control is free to move and negative the impulses of the pump, but alternatively as the abutment shaft is moved inward of the device, so the movement of the piston I is lessened anddelivery starts and will progress to maximum delivery when the abutment shaft is fully home and the piston flange 3 engages the face '4 of the recess in cylinder .5. Inthis condition the piston can no longer move and the indrawn supply of fluid past the inlet foot valve E is .passedto the delivery pipe D. It is a requirement that the volume of the device B be equal to the swept volume of the pump A, and it is preferable, though not essential, that it be placed in the'position as shown, at which position it has an hydraulic advantage.

With the arrangement shown in Fig. 1, one of the advantages consistsin the'ability to keep the pump running and therefore always ready for use, whilst the volume of delivery can be adjusted externally of pump'speed control from nil to maximum. Assuming multiple delivery supplies ous fluid supply can be maintained to separate circuits in a. volume capable of central control.

When the apparatus is employed for secondary systems, i. e., pumping diiferent' fluids and of keeping them separate, and each capable of .variationfrom nildelivery to maximum, then the arrangement shown in Fig.2 is employed. In this arrangement and as illustrated the master pump A creates intermittent pressure with a pulsating client, the fluid moved energising the spring loaded plunger device G hereinafter described and shown in detail, and the system is protected b a safety device consisting of a second spring loaded safety plunger F, later described and hereinafter termed the safety plunger, whose resilient resistance is greater than that in the devices B or G. The spring loaded plunger device G for second ary system pumping is shown in Fig. 4, and consists of a housing 20 in fluid connection at its upper end to the master pump A by a conduit H. Within the housing 20 is mounted a flanged cylinder 2 I. The housing 20 and cylinder 2I are for convenience and as shown secured to the upper flange of a foot valve E of normal and known design. A delivery pipe D for receiving the fluid induced about the foot valve 22 enters'the casing from a'head'er as shown'in Fig. 1, continua , uuaaos 5, 23 of the-footvalve E at the" point as 'shown." I The cylinder 2| is provided'witha packed piston "24 adapted to reciprocate within said cylinder-2|. It 'is essential in some cases that no fluid above the piston 24 escapespast the piston 'toenter the secondary delivery system and for such purpose the piston 24 is adequately packed. Conformably said piston 24 is preferably provided with cup leather packing's 25 which are held in place by head and tail discs 26 machined'ontheir periphery to give fluid access to the .cup leathers 2-5, but packing devices may be employed such for instance as piston rings 21, additional cup or U leathers or the like, the, packing employed preferablyjbeing of the type that exerts a cylinder wall pressure that increases or decreases with fluid pressure, The piston 24 is supported on a rod shouldered as at 29 to engage the upper disc 26': and provided at its lower end with a threaded terminal 2 8a upon which are screwed the lock nuts 30, thus securing the piston and its parts as a rigid entity. The rod 28 is threaded at its. upper free end upon'which is secured an. abutment plate 3|, and locknuts 32, a spring 33 being interposed between the abutment plate 3| and face 34 of the recess between the cylinder 2| and housing 20. The upper part of the cylinder 2| is provided with an inwardly projecting flange 35 to arrest abnormal upward movement of the piston 24 but has an opening 36, admitting fluid when the system is in operation under pump impulse to the upper part of the piston 24 which in turn effects delivery of fluid indrawn from the foot valve E through delivery conduit D. When movement of the piston 24 is in the reverse direction, assisted by the spring 33 fluid enters through th foot valves 22. On the delivery stroke of the piston 24 the fluid in the conduit D is set in motion, which motion tends to persist after the said piston has reached the end of its delivery stroke, and this persistence of motion causes the foot valves to open prematurely and admit fluid flow to augment the delivery, there being an appreciable interval of time between the end of the effective delivery stroke of the piston 24 and its immediately effectiv rise to cause the valves 22 of part E to reopen. In this manner the fluid impulses imparted to the spring loaded plunger or piston 24 by the master pump A are transmitted to the fluid surrounding the foot valve E as diagrammatically illustrated in Fig. 2.

If a series of pumping units is controlled by a continuously operating master pump as designed for instance for the circulating system of an oil refinery or oil storage and delivery depot, it is necessary to provide a safety device whereby the fluid induced to flow in the master system cannot cause damage if all the energisin fluid control isolating valves 40 of the secondary system be closed. To obviate such possibility of damage in operation of the system a safety dash pot or plunger device F (Fig. 3) is provided in the master pumping conduit system. This consists of a plunger operating in a cylinder 42 preferably packed against fluid egress in like manner to the piston 24, a piston plate 43 supporting the cup leathers with discs 26 at top and bottom, the lower disc in this case being fast with the piston rod and the assembly secured with lock nuts 44. A spring 45 is interposed between the abutment plate 46 and top disc 26 of the piston plunger. The cylinder 42 is open to atmosphere and the abutment plate 46 is secured to a cross bar or the like 41 bolted athwart the top of cylinder 42. The

spring 45 is of such resistance as to be normally unreactive to master npump fluid reaction and only'becomes responsive when total or nearly total cessation ofutilization of the energy of the master pump may-take place.- It will be'observed from the'diagram' shown in Fig, 2 that by means of the master pumpA,':and by reason of the operation' previously described, several separate fluids'can be simultaneously pumped, and it'is a matter of operational convenience that the master pump itself expendspart of its energy in pumping fluid as shown in Fig. '2, though this latter method of working is not essential. The safetydevice may in some cases be dispensed with and a relief valve and by-pass valve employed;

Fig. 5 is a modification of apparatus for bore hole pumping wherein the conduit His disposed within the delivery pipe D.' z I Conveniently a fitting 50 is adapted toreceive the pipe D as well as the foot valve E and strainer. The cylinder 2| is ported as at 5| to allow fluid induced vthrough'the valve E to be passed to deliverypipe D at each pulsation. r In this form of the invention-the column'of water in C and D may be maintained above the level of the pump so that the suction stroke of the latter is always drowned.

The device as shown is particularly suitable for deep bore hole wells in which space limits the employment of large diameter pipes or of two pipes other than one inside the other.

I claim:

1. Pumping apparatus comprising a primary pumping system including a suction pipe having an inlet valve at its lower end, a delivery pipe communicating with the suction pipe and having a length suflicient to provide a substantial head of liquid, an intermittent pressure pump operative to set up resonant pressure waves in a column of liquid in the suction and delivery pipes, and means for regulating the eifective delivery of the pump comprising a liquid receiving chamber in permanent communication with said column of liquid and having a volume at least equal to the swept volume of the pump, a resiliently mounted piston movable in said chamber and responsive to said resonant pressure waves, and piston abutment means for varying at will the capacity of said chamber, and a secondary pumping system in communication with the suction pipe of said primary pumping system, comprising a plurality of pumping units having respectively spring controlled plungers responsive to the pressure waves in said column of liquid in said primary pumping system for operating said secondary pumping system.

2. Pumping apparatus according to claim 1, wherein the pumping units of said secondary pumping system are provided respectively with individual foot valves for controlling the pumping of fluids separately from. the fluid in said column of liquid.

3. Pumping apparatus according to claim 1, wherein said pumping units of said secondary pumping system are provided respectively with individual foot valves for controlling the pumping of fluids separately from the fluid in said column of liquid, and said spring controlled plungers comprise pistons each of which is connected to receiv the energy of said column of liquid on one side and to impart said energy to a separate fluid on its other side.

4. Pumping apparatus according to claim 1, wherein said pumping units of said secondary pumping system are provided respectively with individual foot valves forcontrolling the pumping of fluids separatelyfrom the-fluid in-isaid-column of liquid, and wherein each of-said pumping units comprises a cylinder open atweach end-and in communication Wi-ththe respective 'fo ot=va1ve and each of 'said spring controlled plungerscomprises a piston recipro'cab-lein the respective cylinder in response to intermittent pressure in said column of liquid, a, rod in each'cylinderconnected to the piston therein and carrying a spring abutment, a spring interposed-between"said abutment and anendof the cylinder, an externalhousing containing :said spring and "cylinder and connected to transmit energylfrom said column of liquid to'onesid'e of the-respe'ctivezpiston, an'd'a delivery conduit in -said housing communicating'with the other sideof the'respectivexpiston.

5. Pumping apparatus according to claim -1, wherein said pumping units in said secondary pumping system are provided with foot valves for controlling the'pumping-of fluids separately'from the fluid in said column of l-iquid,-'andin='cluding means for interrupting said communication between said primary :pumping system and the pumping units of said :secondary pumping 'system, and a spring loaded plunger in communication with the delivery pipe :of said primary pumpingsystem andsubject to pressure in said column of liquid,-and yieldable when said pressure becomes excessive.

. :LEWIS BURN.

REFERENCES CITED Thefollowing references are of 'record-inthe' file of this patent:

UNITED STATES PATENTS Number Name "Date 204,747 Maxim June 11,'1878 888,803 Haskell et a1 .'May 26, 1908 1,702,649 'Gentzen .Feb. '19, 1929 1,941,593 Bellocq Jan. 2, 1934 2,232,678 Dickinson Feb. 25', I941 FOREIGN PATENTS Number Country -'Date 113,797 Switzerland v 1926 433,570 Germany .1926

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