Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B43/00—Machines, pumps, or pumping installations having flexible working members
  • F04B43/0009—Special features
  • F04B43/0027—Special features without valves
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B43/00—Machines, pumps, or pumping installations having flexible working members
  • F04B43/0009—Special features
  • F04B43/0018—Special features the periphery of the flexible member being not fixed to the pump-casing, but acting as a valve

Definitions

• This invention relates to a positive-displacement pump and more particularly to a positive-displacement pump, comprising: (I) a submersible pump housing having at the lower portion thereof an inlet for liquid to be pumped, having at the upper portion thereof an outlet for liquid being pumped, and having a variable volume pump chamber communicating with the inlet and the outlet, (II) a pumping mechanism including a displace ⁇ ment member which is disposed in the pump housing and movable therein, and a driving device by means of which the displace ⁇ ment member can be actuated to reduce repetitively the volume of the pump chamber and which comprises a lifting member connected with the displacement member, (III) a one-way inlet valve provided between the inlet and the pump chamber, and (IV) a one-way outlet valve provided between the pump chamber and the outlet.
• the pump according to the invention is useful as a submersible pump, i.e. a pump submerged in the body of liquid from which the liquid being pumped is taken and, accordingly, a pump which operates without suction head.
• the pump may be lowered below the water level in a well, a pond or other water supply or in a tank or other liquid reservoir from which water is to be taken by means of the pump.
• An object of the invention is to provide a simple and inexpensive submersible positive-displacement pump the pump chamber of which can be filled very rapidly by gravity flow from the surrounding body of water.
• the pump is primarily characterised in that the inlet communicates with the pump chamber by way of an annular gap between the displacement member and a circumferentially extending pump housing side wall which defines the pump chamber, and in that the one-way inlet valve includes a flexible sealing collar which bridges the annular gap throughout the circumferential extension thereof and one circumferential end of which is sealingly affixed to the pump housing or the sealing member and the other circumferential end of which is movable in the pump chamber towards and away from the said pump housing wall under the influence of a pressure differential between the inlet and the pump chamber.
• the illustrated pump is adapted for use as a well pump and, more particularly, is intended to be lowered to a posi ⁇ tion below the water table in a drilled well.
• the pump comprises a housing which is circular in cross- section and comprised of a base part 10A and a top part 10B secured to the base part.
• the base part 10A forms a generally cylindrical cage into which water may flow freely (without any significant pressure drop) from the body of water in which the pump is submerged. Openings 11 through which the water enters may be provided with a straining cloth (not shown) or may themselves form strainer apertures in the side wall of the base part.
• a waist 13 is formed in the upper portion of the base part and retains within it the lower portion of the top part 10B; to this end the lower portion of the top part is provided with a comple ental waist 14.
• the waist 14 may readi- ly be positioned within the waist 13 of the base part, the last-mentioned waist may be split so that it can readily be expanded.
• a retaining ring 15 applied after the top part 10B has been mounted secures the top part reliably.
• the waist 14 of the top part merges upwardly with an intermediate portion 16 which initially widens and then tapers upwardly towards.an outlet throat 17.
• a riser tube or hose 18 is connected to the latter.
• the interme ⁇ diate portion 16 defines an outlet chamber 19 which chamber communicates with the base part 10A by way of the central circular opening 20 defined by the waist 14 of the top part.
• a pump chamber 21 is provided in the pump housing 10A/10B.
• the pump chamber is defined partly by the inner side 22 of the lower portion of the waist 14 and partly by a sealing collar 23 which forms part of a bowl-shaped body 24 of flexible material and serves as an inlet valve.
• the bottom wall 25 of the bowl-shaped body 24 is domed and delimits the pump chamber downwardly.
• the rotationally sym ⁇ metrical sealing collar 23 when viewed in axial diametrical section, has an arcuate, outwardly convex contour such that the largest diameter of the collar is about halfway between the upper, free end or rim 23A of the collar and the lower end 23B which merges with the bottom wall 25 and such that the two ends 23A, 23B are of approximately equal diameters.
• the shape and dimensions of the sealing collar 23 and the properties of the material the collar is made of are chosen and matched such that the collar moves away inwardly from the pump housing wall 22 as soon as the pressure of the liquid surrounding the collar exceeds the pressure within the pump chamber and is moved into sealing engagement with the surrounding pump hous ⁇ ing wall 22 as soon as the pressure of the liquid within the pump chamber exceeds the pressure outside it.
• a very small pressure differential across the collar is suffi ⁇ cient to open or close the flow passage controlled by the collar.
• the material of the collar has to possess such a strength and such a degree of inextensibility that the collar can endure the hydrostatic pressure resulting from the column of water in the riser hose. Some elasticity of the material may be advantageous, but preferably at least the top or free end 23 is extendable only to a small extent.
• the bowl-shaped body 24, which preferably is made of plastic by blow moulding, vacuum moulding or any other suit ⁇ able process for making thin-walled plastic articles, is supported by, and preferably is secured to, the upper side of a displacement member in the form of a relatively heavy body 27 which is vertically movable in the base part 10A of the pump housing.
• This body serves during its upward movement to contract the pump chamber 21, and thereby to displace liquid therein upwardly through the opening 20, and during its down ⁇ ward movement to cause the pump chamber to expand.
• the displacement member 27 in turn is supported by a lifting element 28 in the form of a rod or cable extending centrally upwardly through the pump housing 10A/10B, the outlet throat 17 of the pump housing and the riser hose 18 to a driving device D which is not shown in detail.
• the lifting element 28 and, accordingly, the displacement member 27 are reciprocated vertically over a certain distance in operation of the pump.
• Abutments may be provided on the pump housing to limit the verti- cal movement in both directions.
• the displacement member 27 varies the height, and thereby the flow-through cross-sectional area, of the annular gap 29 which is defined by the displacement member and the pump housing wall 22 and which is bridged by the sealing collar 23. How- ever, the gap 29 is wide enough to permit filling of the pump chamber 21 rapidly and substantially with no pressure drop even when the displacement member is in its uppermost posi ⁇ tion.
• an outlet valve member 30 which is slidably movable along the lifting member 28 and comprises a tubular stem 31 and a valve disc 32 made integral ⁇ ly with the lower portion of the stem.
• the valve disc 32 is adapted to be in sealing engagement with the inner side 33 of the upper portion of the waist 14 of the housing part 10B under the influence of the weight of the valve member and the hydrostatic pressure in the outlet chamber 19 when that pressure exceeds the pressure in the pump chamber 21.
• the valve member 30 may be made of any suitable material, such as plastic, of greater density than water.
• the pump is lowered to a position some distance below the water table in a well pipe or well hole B the wall of which is indicated by vertical phantom lines in the drawing.
• the pump housing is clamped against the wall of the tube or hole at the intermediate portion 16 of the top part 10B of the pump housing under the influence of the hydro ⁇ static pressure in the pump housing resulting from the column of liquid, in the riser hose 18.
• the intermediate portion 16 can be expanded elastically in the radial direc- tion.
• the intermediate portion 16 of the pump housing is formed with vertical grooves defining passages which extend between the upper and lower end of the intermediate portion and are always open.
• Fig. 1 shows the pump in a phase of operation in which the lifting member 28, and thus the displacing member 27 and the bowl-shaped body 24, are near the end point of the downward stroke. Accordingly, the pump chamber 21 approaches its condi ⁇ tion of maximum volume, but water may still enter the pump chamber through the housing openings 11 and the annular passage 34 between the pump housing wall 22 and the sealing collar 23. The pressure resulting from the overlying column of liquid maintains the valve member 30 in closed position against the valve seat formed by the wall 33.
• valve member 30 When the lifting member 28 and the displacement member 27 are then allowed to move downwardly, the valve member 30 again closes against the seat 33 so that the pump chamber 21 is isolated from the hydrostatic pressure in the outlet chamber 19.
• the water around the pump housing 10A/10B can therefore displace the upper portion of the sealing collar 23 inwardly and flow through the annular passage 34 into the pump chamber 21 with substantially no pressure drop (see Fig. 1) .
• the passage 34 opens over a very large flow-through cross-sectional area. Since, in addition, the flow path of the water is very short, the pump chamber 21 is filled very rapidly; for practical purposes the filling time may always be taken as equal to the time the displacement member requires for its downward stroke. In practice, the pump can therefore always operate without filling problems at the rate at which the driving device is capable of moving the lifting member and the displacement member. Because the hori ⁇ zontal cross-sectional area of the pump chamber 21 can be nearly as large as the interior cross-sectional area of the base part 10A of the pump housing, the stroke volume may be large even when the stroke length is short.
• the pump housing wall 22 serves as a stationary valve seat which coacts with the reci ⁇ procating sealing collar 23.
• This arrangement is normally preferred, but it is possible within the scope of the inven ⁇ tion to affix the sealing collar 23 to the pump housing wall 22 and arrange for its lower annular end 23B to coact with the displacement member 27 which then serves as a movable valve seat.
• other modifications are also possible within the scope of the invention.
• water may slowly leak between the valve member 30 and the lifting member 28 under the influence of the hydrostatic pressure resulting from the column of water in the riser hose 18.
• This leakage is not sufficient, however, to increase the pressure within the pump chamber 21 and thereby cause the sealing collar 23 to engage the pump housing wall 22. Instead, the leaking water may flow past the sealing collar into the body of water around the pump.
• the water column in the riser hose 18 may therefore sink slowly so that the pressure in the outlet chamber 19 is equa ⁇ lised and the clamping of the intermediate portion 16 against the wall of the well tube or well hole gradually disappears.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Details Of Reciprocating Pumps (AREA)
• Reciprocating Pumps (AREA)
• Polysaccharides And Polysaccharide Derivatives (AREA)

Applications Claiming Priority (2)

Publications (2)

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ID=20374835

Family Applications (1)

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Cited By (1)

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• 1989
  • 1989-01-24 SE SE8900237A patent/SE467795B/sv unknown
• 1990
  • 1990-01-24 AT AT90902412T patent/ATE92593T1/de not_active IP Right Cessation
  • 1990-01-24 BR BR909007049A patent/BR9007049A/pt not_active IP Right Cessation
  • 1990-01-24 AU AU49525/90A patent/AU631181B2/en not_active Ceased
  • 1990-01-24 DE DE90902412T patent/DE69002613T2/de not_active Expired - Fee Related
  • 1990-01-24 JP JP2502411A patent/JPH04503985A/ja active Pending
  • 1990-01-24 WO PCT/SE1990/000053 patent/WO1990008898A1/en active IP Right Grant
  • 1990-01-24 DK DK90902412.7T patent/DK0455696T3/da active
  • 1990-01-24 EP EP90902412A patent/EP0455696B1/de not_active Expired - Lifetime
  • 1990-01-24 ES ES90902412T patent/ES2044558T3/es not_active Expired - Lifetime

Non-Patent Citations (1)

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