WO2014059451A1 - Pump - Google Patents

Description

PUMP

BACKGROUND OF THE INVENTION

[0001] This invention relates to a pump assembly suitable for dispensing and simultaneously mixing two or more constituents. [0002] The invention is described hereinafter with reference to the dispensing of a fluent explosive mixture. This however is exemplary only and is non-limiting.

[0003] Certain fluent explosives, in emulsion form, should be mixed with a sensitiser, at or immediately before the time of placement, to be effective. The ratio between the emulsion and the sensitiser, on a volume basis, may be of the order of 97:3. The dispensing of a quantity of sensitiser which is small relative to the quantity of emulsion can call for precision techniques. At least for this reason the use of an explosive mixture comprising, say, two ingredients of more or less equal volume, is preferable, for the preparation thereof can be achieved with a satisfactory degree of accuracy using relatively unsophisticated equipment. [0004] Additionally, many applications call for relatively small quantities of explosive which can be prepared easily and reliably, more or less on demand.

[0005] A need thus exists for the capability to dispense comparatively small and generally equivalent quantities of explosive constituents reliably and accurately in a manner which allows the constituents to be mixed at the time of placement into a borehole. SUMMARY OF INVENTION

[0006] The invention provides a pump assembly which includes a first pump structure with which a first collapsible container, which contains a first composition, is engageable, a second pump structure with which a second collapsible container, which contains a second composition, is engageable, an outlet manifold and an actuating arrangement operable to collapse the containers at a controlled rate, whereby quantities of the first composition and of the second composition are expelled from the respective containers into the outlet manifold.

[0007] The pump assembly may include a reaction member and each collapsible container may be engaged with, e.g. positioned between, the actuating arrangement and the reaction member.

[0008] The actuating arrangement may be operable by means of a pressurised fluid (liquid or gaseous), by means of an electrically driven device such as a motor drive, or manually, for example by using a screw, a lever, a ratchet or any similar arrangement which can apply a force in a controlled way.

[0009] In one form of the invention two side-by-side collapsible containers are used in the pump assembly.

[0010] Each collapsible container may be in the form of a collapsible bellows, a corrugated container, or the like.

[0011] It is envisaged that the collapsible containers are disposable.

[0012] Mixing of the first and second compositions may be effected by means of a suitable mixing device which is embodied within or associated with the outlet or discharge manifold or a dispensing nozzle, or which is located downstream or upstream of the outlet manifold.

[0013] Two containers of substantially equal size may respectively be engaged with the pump assembly which, upon operation, produces a mixture with substantially equal quantities of the compositions from the containers. The percentage of each composition in the mix can be varied by making a cross-sectional area of one container different to the cross-sectional area of the other container.

[0014] The invention further provides a container which includes a collapsible body, a composition for an explosive mixture inside the body, the body including an outlet, a seal over the outlet and a base which is movable toward the outlet when the body is collapsed.

[0015] A seal may be provided on an outer surface of the base.

[0016] The base may be recessed and may be of generally conical form.

[0017] The body may be made to be collapsible in any appropriate way. The body may have a wall which is corrugated or which has a concertina-type formation so that, when the body is externally pressurised, it can collapse.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The invention is further described by way of examples with reference to the accompanying drawings in which:

Figure 1 is a side view of a pump according to one form of the invention;

Figure 2 illustrates in perspective and in an exploded configuration components of a casing for the pump; Figure 3 shows a pump assembly which, together with the casing in Figure 2, make up the pump of Figure 1 ;

Figure 4 is a view in perspective of a container which includes a collapsible body which is intended for use in the pump assembly;

Figure 5 shows the collapsible body of Figure 4 from one side and in cross-section;

Figure 6 is a side view, in cross-section, of a container of the type shown in Figure 4 engaged with the pump assembly shown in Figure 3;

Figure 7, which is similar to Figure 3, illustrates another pump assembly according to the invention;

Figure 8 is a cross-sectional view of the pump assembly of Figure 7; and

Figure 9 shows details of a bayonet-type arrangement which can be used in a pump assembly according to the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0019] Figure 1 of the accompanying drawings illustrates from one side a pump casing 10 which houses a pump assembly 12 which is shown in perspective in Figure 3. Two relatively short flexible hoses 14 and 16 (see Figure 3) extend from the casing 10 and are coupled to a control valve 18. An air supply hose 20 is connected to the control valve 18 and to a source of pressurised air, not shown.

[0020] The casing 10 has various handles 24 at convenient locations. [0021] A static mixer 26 (notionally shown) of any appropriate type known in the art is connected to a short pipe 28 which protrudes from a leading end 30 of the pump casing. A placement lance or elongate nozzle 34 is connected by means of a flexible hose 36, of any suitable length, to the static mixer. [0022] Figure 2 shows the pump casing 10 in perspective, in an exploded configuration and on an enlarged scale. The casing is formed from a first casing component 10A which acts as a base and a second casing component 10B which acts as a lid. The components are interengageable in a secure manner in any appropriate way.

[0023] The first casing component 10A includes various locating formations 40 which are shaped and positioned to accommodate the pump assembly 12. Similar formations, not visible, are provided on the second component 10B.

[0024] The pump assembly 12 (see Figure 3) includes two side-by-side pump structures 44 and 46 respectively.

[0025] The pump structure 44 includes a housing 50 in which is formed an elongate cylindrical bore 52 (Figure 6). At one end the housing terminates in a reaction member which is in the form of a flange 54. A sub-manifold 56 is fixed to the flange through the medium of a number of bolts 58. An O-ring seal 60 is located between opposing surfaces of the flange 54 and the sub-manifold 56. The flange 54 has a centrally positioned aperture 62 which is surrounded by a seal formation 64. The sub-manifold 56 carries a pointed foil breaker 66 which protrudes into the aperture 62, and a nonreturn valve assembly 68. The sub-manifold 56 has an outlet port 70 on one side - this is shown in Figure 3 and in dotted outline in Figure 6.

[0026] An actuating arrangement 72 is formed at one end of the housing 50. The actuating arrangement 72 includes a screw member 74 which is engaged with a component 76 which has a bayonet fitting 76A. The bayonet fitting 76A is inserted into a mouth 78 of the bore and is moved along a complementary formation 76B in the mouth and then twisted, thereby to couple the component 76 securely to the housing 50. An O-ring seal 80 is positioned between opposing surfaces of the mouth and the component 76.

[0027] The actuating arrangement 72 further includes a hose connector 82 which is fixed to the member 74. This is used to couple the flexible hose 16 to the housing - see Figure 3. The hose connector leads to an outlet port 84 which opens into the bore 52.

[0028] At an intermediate location the housing includes an exhaust port 86 which is vented to atmosphere.

[0029] The pump structure 46 is substantially identical to the pump structure 44. The two housings 50 of the two pump structures are interconnected by means of supporting components 90 - see Figure 3. The outlet ports 70 from the sub-manifolds 56 are coupled to an outlet manifold 92 which has a discharge port 94. The pipe 28 shown in Figure 1 extends from the discharge port 94.

[0030] Each pump structure 44, 46 is intended to be used with a respective container 96 which includes a collapsible body 98, shown in perspective, and from one side in cross-section, in Figures 4 and 5 respectively, and a fluent composition 100, for an explosive material, located inside the container. The body 98 has a corrugated or bellows-like wall 102 of tubular form which is closed at a base 104 of the body. The body, at an opposing end 106, has a dispensing outlet 108 in the form of an externally screw-threaded tubular spout. A cap 1 10 is threadedly engaged with the spout. A seal formation 112 is formed at a shoulder 1 14 at a base of the dispensing outlet.

[0031] The base 104 of the body has a thickened wall 118. The base is thereby strengthened. The base has an internally projecting conical formation 120 - see Figure 5. An outer surface of the wall 1 18 carries two circumferentially-extending O-rings 124 and 126 which are dimensioned and positioned to engage with a close, sealing, yet sliding, fit to a surface 52A of the cylindrical bore 52, see Figure 6.

[0032] The container 96 is packed under factory conditions with the fluent composition 100 of an explosive material. The container which is engaged with the pump structure 44 contains one ingredient (composition) of the explosive material and the container which is engaged with the pump structure 46 contains a different ingredient (composition) of the explosive material. These ingredients, when mixed in substantially equal portions with each other, make up a fluent explosive material. The nature of each composition is not described herein for use can be made of explosive mixtures which are known in the art.

[0033] After a container has been filled with its explosive composition the spout 108 is sealed by means of a thin sheet of foil 140 (Figure 4) and the cap 1 10 is then threadedly engaged with the spout thereby to form an additional seal for the container.

[0034] In order to load a pump structure with a collapsible container, the bayonet fitting 76A is disengaged from the formation 76B and the component 76 is removed from the remainder of the housing. The cap 1 10 on the container is unscrewed and the container is inserted, spout first, into the bore 52. The container is pushed into the bore until the foil breaker 66 (Figure 6) penetrates the foil 140 which is adhered to the dispensing spout. At this point the seal formation 1 12 is brought into sealing engagement with the formation 64 on the flange 54 which acts as a reaction member. The bayonet fitting is then re-engaged with the housing to secure the component 76 to the housing. [0035] The pump assembly can be actuated by using a suitable pressurised fluid, e.g. compressed air or pressurised water, as an energy input source. These forms of energy are readily available at most underground locations and blasting sites. The actuator arrangement 72, in this example, is one wherein each of the containers 96 is designed to interact with the respective pump structure, in a piston-like manner.

[0036] The containers in the pump structures respectively include explosive compositions which are to be mixed in a desired ratio, in this example 50/50, in order to form an explosive material. Once the valve 8 (Figure 3) is opened, pressurised fluid (compressed air or pressurised water) can flow into a respective chamber 150, see Figure 5, adjacent the conical formation 120 of each container. As the fluid pressure is increased the volume of each chamber 150 is expanded and the collapsible containers are compressed in a controlled manner, substantially, to the same extent. Thus, in one respect, the base of each container respectively forms a type of piston which moves, under fluid pressure in a cylinder which forms part of the support structure. The contents of each container are expelled through the respective spouts 108 and pass through the respective non-return valve assemblies 68.

[0037] The compositions from the containers then flow, in substantially equal volumes, through the respective outlet ports 70, enter the outlet manifold 92 and exit via the discharge port 94. The constituents are mixed by the static mixer 26 referred to in connection with Figure 1 , and the resulting explosive mixture passes via the tube 36 to the lance 34 which is used by an operator to place the fluent explosive mixture into a borehole. The lance may include a control valve to stop and start the flow of the mixture from the lance. Alternatively or additionally, the control valve 18 can be used for this purpose.

[0038] Once the compositions in the containers have been completely expelled the valve 18 is shut and the collapsed containers are removed from inside the pumps. They can be replaced by fresh containers whereafter the mixing and dispensing process is repeated.

[0039] Each collapsible container is a disposable item and is designed so that its conical formation 120 is sufficiently strong to act as a piston when a pressurised fluid is introduced into the volume 150. The O-rings 124 and 126 effectively act as piston rings. In a different arrangement a dedicated piston (not shown) is provided. The piston may for example, be similar to the conical member 120 of the collapsible container. The piston is then retained in the bore and is used to apply force, generated by the pressurised fluid in the volume 150, on the collapsible container.

[0040] If the explosive material is to have a different make-up say, for example, 70% of one composition and 30% of the other composition, then the effective cross-sectional areas of the two containers are correspondingly altered to be in the ratio of 70:30. As the containers are linearly collapsed to the same extent, when actuated, the volumes of the compositions expelled by the respective containers are then in the ratio of 70:30.

[0041] In another variation of the invention a bayonet fitting structure is provided between the housing 50 and the flange 54, and the bolts 58 are not used. The reason for this is that once the body of the container has been fully collapsed it is convenient to open the housing at a location which is adjacent the flange 54 so that the collapsed container can easily be removed from an interior of the pump housing. [0042] Figures 1 to 6 illustrate details of a pump assembly 12 according to the invention which makes use of a pressurised fluid, as a driving force in an actuator arrangement 72, to expel the ingredients of an explosive material so that they can be mixed prior to placement. Figure 7 shows, in perspective, a pump assembly 198 according to another form of the invention, which has a manually operable actuator arrangement 200, while Figure 8 illustrates in cross-section certain details of the pump assembly 198.

[0043] There are a number of similarities between the assembly 198 shown in Figure 7 and the pump assembly 12 and, for this reason, the pump assembly 198 is not described in detail. The pump assembly 198 includes supporting structure 202 which comprises side-by-side pump structures 202A and 202B respectively which are respectively engageable with substantially identical collapsible containers 204 and 206. Each container (see Figure 8) includes a respective body 210 with a corrugated or concertina-type wall 212, a flat base 214, and a dispensing spout 216 which opposes the base.

[0044] The structure 202 has an outlet or discharge manifold 220 and an opposing actuating arrangement 222 which includes a force applicator 224 comprising a press plate 226 and a spindle 228. The press plate 226 is movable towards or away from the outlet manifold 220 along guiding rods 230. The spindle 228 is elongate and threaded and is positioned between the containers 204 and 206 and is coupled, at one end, to a retentive bush assembly 232 which allows rotation of the spindle 228 while keeping the spindle attached to the outlet manifold 220. [0045] The press plate 226 has a threaded member 234 which is held inside a collar 236 which is centrally positioned in the press plate 226. A hand wheel 238 is fixed to an end of the spindle 228 which is remote from the outlet manifold. Upon rotation of the hand wheel the spindle is rotated and the threaded member 234 is either relatively advanced along the spindle towards the outlet manifold 220 or is moved away from the outlet manifold, according to the direction of rotation of the hand wheel.

[0046] When the press plate 226 is moved towards the outlet manifold 220 the containers 204 and 206 are subjected to compressive forces which cause the contents of the containers to be expelled through the respective dispensing spouts 216. These spouts are engaged in a leak-proof manner with respective sockets in the outlet manifold 220. The contents then flow through respective non-return valves 242 and 244 to an outlet 246 which may contain mixing structure, not shown, to ensure that the contents from the containers 204 and 206 are effectively mixed before placement.

[0047] Effective sealing is achieved by means of a respective O-ring 240 which surrounds each spout.

[0048] When the containers are depleted the hand wheel is rotated to move the press plate fully away from the outlet manifold 220. The spent containers are removed and fresh containers are engaged with the equipment.

[0049] The hand wheel 238 can be used for rapidly advancing the press plate, or for retracting the press plate, according to requirement. It is possible, in addition to the hand wheel, to provide a dosing lever 252 which is coupled to the hand wheel via a oneway bearing or ratchet arrangement, not shown. The dosing lever when moved in one direction, say in a clockwise direction, advances the spindle through a fixed arc. At the end of this stroke the dosing lever, if released, returns to its starting position under the action of an internal spring (not shown). On the return stroke the dosing lever moves freely relative to the spindle. The use of the dosing lever means that it is possible to rotate the spindle through a small arc which is precisely determined by the interaction of the dosing lever with the one-way bearing and spindle. For example, it may be known from earlier tests and design factors that three strokes of the lever are sufficient to dispense a predetermined quantity of the explosive constituents from the containers. The lever thus provides a means for accurately determining the quantity of material which is dispensed. Use of the lever is, however, not obligatory for, particularly when larger quantities of explosive material are to be dispensed, the hand wheel can be used. As indicated once the containers are depleted the hand wheel would normally be used to return the press plate to its fully retracted position relative to the discharge manifold.

[0050] Reference has been made hereinbefore to the use of a bayonet fitting structure to couple a container to the pumping equipment. Figure 9 shows possible details of this type of construction. Figure 9 depicts a container 260 with a corrugated body which may be collapsed by means of a pressure plate which acts externally on the container, or which has an internal piston arrangement, similar to that shown in Figure 6, which is actuable by means of a pressurised fluid which is brought to the container through a hose 262 coupled to a cap 264 at a trailing end of the container. A leading end of the container has a spout 266 which is screw-threaded and from which a cap (not shown) must be detached before the contents of the container can be dispensed.

[0051] A dispensing member 270 can be coupled to the leading end of the container, when required. The dispensing member, which comprises a bayonet cap, is cup- shaped and has a socket 272 which fits over the spout 266. The container carries outwardly projecting spigots 274. The dispensing member 270 has hook-shaped slots 276 which are engageable with the spigots and which lock the dispensing outlet to the container, with a bayonet-fitting type action, when the dispensing member is twisted relative to the container. An outlet 280 from the socket, which contains a non-return valve (not shown), is thereby brought into alignment with an outlet tube 284 which leads to a mixing and dispensing mechanism, not shown.

[0052] Once the contents of the container are depleted the bayonet cap 270 is detached. The spent container is then replaced by a fresh container. The hose 262 can be attached to the trailing end of the container by means of a snap coupling. Thus the bayonet cap can be engaged with a container, or disengaged from a spent container, with ease.

Claims

A pump assembly (12, 198) which includes a first pump structure (44,202A) with which a first collapsible container (96, 204), which contains a first composition, is engageable, a second pump structure (46, 202B) with which a second collapsible container (96, 206), which contains a second composition, is engageable, an outlet manifold (92, 220), and an actuating arrangement (72,222), operable to collapse the containers at a controlled rate, whereby quantities of the first composition and of the second composition are expelled from the respective containers into the outlet manifold (92, 220).

A pump assembly (12, 198) according to claim 1 wherein the outlet manifold (92, 220) includes a discharge outlet (94, 246) which in use is connected to a placement hose (34).

A pump assembly (12, 198) according to claim 1 or 2 wherein the first container (96, 204) includes a body (98, 210) with an outlet (108, 216) at one end of the body which is brought into communication with the outlet manifold (92, 220) when the first container (96, 204) is engaged with the first pump structure (44, 202A) and a base (104, 214) at an opposing end of the body, and wherein the actuating arrangement (72, 222) is operable to move the base (104, 214) towards the outlet (108,216) thereby to pressurise the first composition inside the body (98, 210) and so cause a quantity of the first composition to be expelled through the outlet (108, 216) into the outlet manifold (92, 220).

A pump assembly (12) according to claim 3 wherein the actuating arrangement (72) includes, for each pump structure (44, 46), a respective chamber (150) which acts on the base (104) and which, in use, is expanded by means of a pressurised fluid.

A pump assembly (198) according to claim 3 wherein the actuating arrangement (222) includes a pressure plate (226) which acts on each base (214) and a spindle (228) which is operable to cause the plate (226), and thereby each base (214), to move towards the outlet (216) and so pressurise the respective compositions inside the containers.

For use in the pump assembly of claim 3 a container (96, 204) which includes a body (98, 210) with a corrugated wall, an outlet (108, 216) at one end of the body, a base (104, 214) at an opposing end of the body and an explosive composition (100) contained inside the body.

A container (96) according to claim 6 which includes at least one seal (124,126) which circumferentially surrounds the body at a location which is adjacent the base (104).

A container according to claim 6 wherein the body (98, 210) includes a bayonet- type fitting (274) which is engageable with a complementary formation in a respective pump structure.