WO2008095206A1

WO2008095206A1 - Mixer pump

Info

Publication number: WO2008095206A1
Application number: PCT/ZA2007/000087
Authority: WO
Inventors: Rudolph Teodor BÜHRMANN; Rudolph BÜHRMANN; Frank Neimann
Original assignee: African Explosives Limited
Priority date: 2007-01-30
Filing date: 2007-12-12
Publication date: 2008-08-07
Also published as: BRPI0721208A2; AP2009004921A0; CL2008000281A1; ATE554290T1; AP2665A; PL2106502T3; EP2106502A1; ZA200904405B; EP2106502B1; PE20081745A1; PT2106502E; DK2106502T3; MX2009007321A

Abstract

A mixer pump which has two reservoirs for two constituents, two pumps for pumping the constituents, and a housing which contains the reservoirs and the pumps and which has formations which are respectively partly complemental to, and which received parts of, the reservoirs.

Description

MIXER PUMP

BACKGROUND OF THE INVENTION

[0001] This invention relates to the construction of a pumping device which functions to deliver two constituents which are drawn from respective reservoirs to a common discharge point.

[0002] A pumping arrangement of the aforementioned kind, referred to herein as a mixer pump, is required in various applications including, for example, for the mixing of a non-explosive emulsion and an activator to produce an explosive gel. Typically the mixer pump is employed in an underground location and, as a consequence, the pump is subjected to arduous conditions of use.

[0003] Apart from a requirement of physical strength the mixer pump should be compact and below a predetermined weight and the constituents which are to be mixed should preferably be housed in tanks or reservoirs together with the required pumping equipment, in a single housing. This should be done in a manner which makes the mixer pump easy to maintain and repair, when necessary.

[0004] It is an object of the present invention to provide a mixer pump which at least partly addresses the aforementioned requirements.

SUMMARY OF INVENTION

[0005] The invention provides a mixer pump which includes a first reservoir for a first constituent, a second reservoir for a second constituent, a housing which includes a first formation which is at least partly complemental in shape to the first reservoir and with which the first reservoir is eπgageable, and a second formation which is at least partly complemental in shape to the second reservoir and with which the second reservoir is engageable, a first pump inside the housing for pumping the first constituent to a discharge point and a second pump inside the housing for pumping the second constituent to the discharge point.

[0006] A first filter may be located between the first reservoir and the first pump positioned so that the first pump draws the first constituent from the first reservoir through the first filter.

[0007] The first filter may include an enclosure with an outlet from the enclosure to an inlet to the first pump, a filter element which is located inside the enclosure, and an inlet at a lower end of the enclosure through which the first constituent is drawn from the first reservoir.

[0008] The first reservoir is preferably positioned so that it at least partly overlies the enclosure.

[0009] The housing may include an opening at a lower side through which the enclosure of the first filter is insertable. A cap may be engageable with the opening, in order to retain the enclosure in its position and to seal the opening.

[0010] The filter element is preferably removable from the enclosure upon disengagement of the cap from the opening.

[0011] The first reservoir may include a first filler aperture which extends through an opening in an upper side of the housing, and a first cap which is engaged with the filler aperture. Similarly the second reservoir may include a second filler aperture which extends through an opening in an upper side of the housing and a second cap may be engaged therewith.

[0012] The first pump may be positioned at least partly between the first filter and the second reservoir.

[0013] The pump may be actuable by means of a piston which is reciprocally movable inside a cylinder positioned at least partly between the first and second reservoirs.

[0014] Sighting windows or apertures may be positioned at suitable locations of the housing to enable the contents of the first and second reservoirs, which are made from or which include a transparent or translucent material, to be assessed.

[0015] The various components may be retained inside the housing by engagement of a closure with a part of the housing. Preferably the closure constitutes a section of the housing. The closure may comprise a flap which is movable relatively to the remainder of the housing along a line of weakness or a hinge joint.

[0016] The first pump may discharge into a pipe and the second pump may discharge into a tube, located at least partly inside the pipe, with an end of the tube being located inside the pipe so that the second constituent is discharged from the tube directly into the first constituent in the pipe and the two constituents are thereby mixed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The invention is further described by way of example with reference to the accompanying drawings in which:

Figure l is a side view in section of a mixer pump according to the invention;

Figure 2 is a view in perspective of the mixer pump from a first end; and

Figure 3 is a perspective view of the sectioned mixer pump shown in Figure 1 , from a second end of the pump which opposes the first end.

DESCRIPTION OF PREFERRED EMBODIMENT

[0018] The accompanying drawings illustrate a mixer pump 10 according to the invention. The invention is primarily concerned with the manner in which components and parts of the mixer pump are assembled in a compact yet easy to assemble and disassemble configuration. The manner in which some of the components of the mixer pump work is not important to an understanding of the present invention and for this reason the following description does not elaborate on these aspects.

[0019] The mixer pump includes a housing 12, a first reservoir 14, a second reservoir 16, a first pump 18, a second pump 20, a first filter assembly 22, a cylinder 24 and a piston 26 which is mounted for reciprocating movement in a bore of the cylinder.

[0020] The housing 12 has a complex shape and is specifically designed to engage intimately with some of the remaining components of the mixer pump and to provide a wide base for stable support on uneven surfaces. At a first end 30, on an upper surface, the housing has a short upwardly projecting spout 32 which is more or less centrally positioned in a section 34 of the housing which is generally of a rectangular configuration. The first reservoir 14, on its upper surface, is shaped to fit in a complemental manner, in a close-nestling configuration, into the section 34. The reservoir has a first filler aperture 36 which projects through the spout. A first cap 38 is threadedly engageable with the filler aperture to close the aperture.

[0021] The reservoir 14 has a substantially flat ledge 40 which firmly abuts a corresponding ledge 42 in the casing 12, and an opening 44 which places a main section of the reservoir in communication with a downwardly extending portion 46 of the reservoir. This portion terminates in a screw-threaded neck 48 and a cap 50 is threadedly engageable with the neck.

[0022] The filter assembly 22 is located inside the portion 46. The filter assembly includes an enclosure 54 with a lower opening or inlet 56 and an outlet 58 which is in communication with an inlet to the pump 18. A filter element 60 is located inside the enclosure and is firmly held in position by means of an elongate bolt 62. The arrangement is such that, as is indicated by means of a curved arrow 64, a first fluid constituent held in the first reservoir 14, under the action of gravity, can flow through the portion 46 and then upwardly through the inlet 56 into the enclosure 54. This brings the first fluid constituent into the interior of the filter element, which is of circular cylindrical shape, and consequently the first fluid constituent can only pass to the pump 18 if it flows through the filter element. Particles which are trapped by the filter element fall under gravity action to a lower end of the enclosure. The cap 50 is situated in a recess 66 in an underside of the housing and therefore can be removed with ease, when necessary, in order to remove filtered material from filter assembly. A lower surface 68 of the housing extends downwardly more than the lower surface of the cap and thus, in normal usage, protects the cap against abrasion and similar damage

[0023] The pump 18 is actuated by the piston 26 which is reciprocated within the cylinder 24 by means of pressurised air. The pressurised air is drawn from an appropriate source, not shown, and is introduced into the cylinder alternately on opposing sides of the piston by means of a control assembly 70. The manner in which the control assembly works is not important to an understanding of the invention and any suitable device can be used in this regard. It is pointed out though that the cylinder 24 has opposing ends 24A and 24B which are engageable with a press fit in corresponding seals 72A and 72B respectively. The cylinder is bolted in position and is in tight engagement with the seals, and is closely sandwiched between the control assembly 70 and structure 76 which accommodates the seal 72B. The structure 76, in turn, is mounted to a casing 77 of the pump. A sealed protrusion 78 on the casing 77 engages with a bore 79 in the tank 14 so as to support the pump and to provide a sealed connection between the cylinder 24 and the tank 14, via the outlet 58 and the portion 46 along the path designated by the arrow 64. The pump is designed to discharge into a pipe 80 which is formed inside the structure. This pipe leads to a discharge point, not shown, which is at any convenient position on the housing and which is externally accessible in order to couple a flexible hose thereto.

[0024] At a second end 84 the housing has a construction which is similar to that at the right end although on a smaller scale. The housing includes a spout 86 which extends upwardly and the second reservoir 16 has a second filler aperture 88 which passes through the spout. A second cap 90 is threadedly engageable with the aperture 86. A lower end of the reservoir 16 has a discharge aperture through which a second fluid constituent, held in the reservoir, can pass to a suitable filter, not shown, to the second pump 20.

[0025] The second pump 20 is also operated by compressed air, using any appropriate technique. Operation of the second pump 20 is synchronised to the operation of the first pump, by means of the control assembly 70, to ensure that the second pump delivers the second fluid constituent, drawn from the second reservoir, at a rate which is accurately controlled relatively to the rate at which the first pump delivers the first fluid constituent. The second pump discharges into a tube 92 which is positioned inside the pipe 80. The tube has an open end at an appropriate location inside the pipe so that the second fluid constituent is discharged from the tube directly into the first fluid constituent inside the pipe. The tube is of sufficient length to discharge the second fluid into the first fluid at a position in the pipe such that the components are only mixed outside the pump housing 12. Thus no activation of the components takes place inside the housing but the two constituents are mixed automatically as they travel further along the pipe. The flexible hose which is connected to an outlet from the pipe 80 is not shown and is used in a manner known in the art to direct the resulting mixture of the two fluid constituents, typically an explosive emulsion, to a point of use.

[0026] The second reservoir 16 closely abuts a side wall at the second end 84 and is held in position by the interengagement of a portion of its upper surface with a portion of the housing adjacent the spout, which has a close-fitting corresponding shape. The control assembly 70 is directly and closely insertable into a suitable recess 96 in a side of the reservoir. The cylinder 24 is positioned between the control assembly 70 and the structure 76. The pump 20 is closely positioned at a lower end of the housing between opposing surfaces of the reservoir and of the control assembly and a lower wall of the housing. The projecting end of the pump 20 is engaged with the structure 76. This structure also correctly locates the pump casing 77 at one end while, at an opposing end, the pump casing is engaged with the closure 60 of the filter assembly.

[0027] At the first end 30 the housing 12, which is integrally formed, has a closure flap 100 which is joined to the remainder of the housing along a line of weakness 102 which forms a hinge joint. A number of holes 104 are formed at spaced locations in the flap. Fasteners, not shown, can pass through these holes and are threadedly engaged with appropriate substantial bushes, not shown, formed on an inner side of an opposing wall 106 of the housing.

[0028] When the fasteners are disengaged from the wall 106 the flap 100 can be pivoted upwardly about the hinge joint 102. If the caps 18 and 90 are unscrewed from the respective filler apertures then it is possible to withdraw the components of the mixer pump successively from the housing through an aperture 108 which is normally partly closed by the flap.

[0029] The various components of the mixer pump are made, to the extent possible, from suitable tough plastics materials which are lightweight and corrosion and abrasion resistant. Preferably the two reservoirs are made from a transparent or translucent material and sight windows 110 and 112 are formed in the walls of the housing at the first and second ends respectively to enable the fluid constituent inside the respective reservoirs to be viewed.

[0030] Handles or skids can be attached to the housing or can be formed integrally therewith as may be required. [0031] The housing is of compact design and accommodates all of the components of the mixer pump. This is done in a manner which provides a substantial degree of protection for the components but which allows the components to be disassembled, when necessary, for maintenance or repair purposes.

Claims

1. A mixer pump which includes a first reservoir for a first constituent, a second reservoir for a second constituent, a housing which includes a first formation which is at least partly complemental in shape to the first reservoir and with which the first reservoir is engageable, and a second formation which is at least partly complemental in shape to the second reservoir and with which the second reservoir is engageable, a first pump inside the housing for pumping the first constituent to a discharge point and a second pump inside the housing for pumping the second constituent to the discharge point.

2. A mixer pump according to claim 1 which includes a first filter, located between the first reservoir and the first pump, so that the first pump draws the first constituent from the first reservoir through the first filter.

3. A mixer pump according to claim 2 wherein the first file includes an enclosure with an outlet from the enclosure to an inlet to the first pump, a filter element which is located inside the enclosure, and an inlet at a lower end of the enclosure through which the first constituent is drawn from the first reservoir.

4. A mixer pump according to claim 3 wherein the first reservoir is positioned so that it at least partly overlies the enclosure.

5. A mixer pump according to clam 3 or 4 wherein the housing includes an opening at a lower side through which the enclosure of the first filter is insertable and a cap which is be engageable with the opening, in order to retain the enclosure in its position and to seal the opening.

6. A mixer pump according to claim 5 wherein the filter element is removable from the enclosure upon disengagement of the cap from the opening.

7. A mixer pump according to any one of claims 2 to 6 wherein the first reservoir includes a first filler aperture which extends through an opening in an upper side of the housing, and a first cap which is engaged with the filler aperture and the second reservoir includes a second filler aperture which extends through an opening in an upper side of the housing and a second cap engaged therewith.

8. A mixer pump according to any one of claims 2 to 7 wherein the first pump is positioned at least partly between the first filter and the second reservoir and which is actuable by means of a piston which is reciprocally movable inside a cylinder positioned at least partly between the first and second reservoirs.

9. A mixer pump according to any one of claims 1 to 8 wherein the housing includes a closure which comprises a flap which is movable relatively to the remainder of the housing along a line of weakness or a hinge joint.

10. A mixer pump according to any one of claims 1 to 9 wherein, in use, the first pump discharges into a pipe and the second pump discharges into a tube, located at least partly inside the pipe, with an end of the tube being located inside the pipe so that the second constituent is discharged from the tube directly into the first constituent in the pipe and the two constituents are thereby mixed.

11. A mixer pump which has two reservoirs for two constituents, two pumps for pumping the constituents, and a housing which contains the reservoirs and the pumps and which has formations which are respectively partly

complemental to, and which received parts of, the reservoirs.