WO2020118346A1

WO2020118346A1 - Powder spray pump

Info

Publication number: WO2020118346A1
Application number: PCT/AU2019/000153
Authority: WO
Inventors: Craig Fisher
Original assignee: RAPID BUILDING SYSTEMS Pty Ltd
Current assignee: RAPID BUILDING SYSTEMS Pty Ltd
Priority date: 2018-12-14
Filing date: 2019-12-13
Publication date: 2020-06-18
Anticipated expiration: 2021-06-14
Also published as: AU2019399658A1

Abstract

The present disclosure relates to a powder spray or shotcrete pump for use with cementitious materials including but not limited to, gypsum, plaster, mortar, cement and other grouts. In one aspect the powder spray pump comprises an enclosed dry mix storage hopper, a pneumatic motor issuing an airstream to a collector which entrains the dry mix in the airstream and issues this via an outlet to a hose and a handpiece in turn, the powder spray pump further comprising a water pump for issuing a stream of water via a water outlet for delivery to a water hose and the handpiece in turn, wherein the water pump meters water flow rate proportional to a dry mix flow rate so as to maintain a desired water to dry mix ratio for all dry mix flow rates.

Description

POWDER SPRAY PUMP

PRIORITY DOCUMENTS

[0001] The present application claims priority from Australian Provisional Patent Application No. 2018904752 titled“POWDER SPRAY PUMP” and filed on 14 December 2018, the content of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

[0002] The present disclosure relates to a powder spray or shotcrete pump for use with cementitious materials including but not limited to, gypsum, plaster, mortar, cement and other grouts.

BACKGROUND

[0003] Shotcrete, gunite or sprayed concrete is concrete or mortar conveyed through a hose

and pneumatically projected at high velocity onto a surface, as a construction technique. It is typically reinforced by conventional steel rods, steel mesh, or fibres. In most contexts the term "shotcrete" refers to application of a wet mix and involves pumping of a previously prepared concrete to the nozzle and the term "gunite" refers to application of a dry mix and involves placing the dry ingredients into a hopper and then conveying them pneumatically through a hose to the nozzle. Water is then added at the nozzle, with the operator controlling the water flow rate using a valve, potentially resulting in shotcrete of varying consistency.

[0004] Advantages of the dry mix process are that the water content can be adjusted instantaneously, allowing more effective placement in overhead and vertical applications without using accelerators. The dry mix process is useful in repair applications when it is necessary to stop frequently, as the dry material is easily discharged from the hose.

[0005] Known gunite pumps produce large numbers of airborne particulates (dust), which prevents gunite pumps being used in some situations, particularly relatively closed areas such as in the underground coal industry (UCI). In other UCI situations gunite pumps can be used but due to dust levels the pumps create, they impact negatively on the health and safety of those who work with them.

[0006] There is thus a need to provide gunite or dry mix shotcrete pumps that overcome or ameliorate one or more of the problems associated with the aforementioned gunite pumps. Alternatively, or in addition, there is a need to provide gunite or dry mix shotcrete pumps that provide a useful alternative to the aforementioned gunite pumps. SUMMARY

[0007] According to a first aspect there is provided a powder spray pump comprising an enclosed dry mix storage hopper comprising an upper opening equipped with a hatch for closing and sealing the opening, a rotor, a pneumatic motor issuing an airstream to a collector comprising a body which forms an extraction hood over at least a portion of the rotor, wherein in use, as the rotor rotates it delivers dry mix from the hopper to the collector, which entrains the dry mix in the airstream and issues this via an outlet to a hose and a handpiece in turn.

[0008] The term dry mix should be construed as being inclusive of any dry particulate material suitable for use in spray pumping or‘shotcreting’, such as plaster, mortar or cement.

[0009] In one form, the powder spray pump further comprises a water pump for issuing a stream of water via a water outlet for delivery to a water hose and the handpiece in turn.

[0010] In one form, the water pump meters water flow rate proportional to a dry mix flow rate so as to maintain a desired water to dry mix ratio for all dry mix flow rates.

[0011] In a further aspect then, there is provided a powder spray pump comprising an enclosed dry mix storage hopper, a pneumatic motor issuing an airstream to a collector which entrains the dry mix in the airstream and issues this via an outlet to a hose and a handpiece in turn, the powder spray pump further comprising a water pump for issuing a stream of water via a water outlet for delivery to a water hose and the handpiece in turn, wherein the water pump meters water flow rate proportional to a dry mix flow rate so as to maintain a desired water to dry mix ratio for all dry mix flow rates.

[0012] In one form, the powder spray pump further comprises a water accumulator receiving water from the water pump.

[0013] In one form, the pneumatic motor drives the rotor.

[0014] In one form, the pneumatic motor drives the water pump.

[0015] In one form, the pneumatic motor drives the water accumulator.

[0016] In one form, the powder spray pump further comprises a gear train via which the pneumatic motor transmits drive. [0017] In one form, the rotor comprises a disc shaped body with a recessed channel forming a ring extending around an outside of a face of the disc, where the channel is divided into a series of segments by a series of radially extending vanes, so that each segment forms a scoop.

[0018] In one form, the collector comprises a top plate, and a skirt extending down from the top plate and terminating just clear of the face of the rotor.

[0019] In one form, the airstream is issued into the collector in the form of at least one air jet directed at the rotor, so as to agitate dry mix carried on the rotor so that this forms a dust which is retained in the collector, and which becomes entrained in the airstream.

[0020] In one form, the handpiece comprises a body comprising a barrel passing therethrough from an inlet for receiving an airstream entrained dry mix, to an outlet, the barrel further comprising at least one water manifold ring adapted to receive water from a water supply and distribute and inject this water into the barrel at a plurality of points around an internal circumference thereof so as to mix the water with the airstream entrained dry mix.

[0021] According to a further aspect there is provided a handpiece for a powder spray pump, the handpiece comprising a body comprising a barrel passing therethrough from an inlet for receiving an airstream entrained dry mix, to an outlet, the barrel further comprising at least one water manifold ring adapted to receive water from a water supply and distribute and inject this water into the barrel at a plurality of points around an internal circumference thereof so as to mix the water with the airstream entrained dry mix.

[0022] In one form, the handpiece further comprises a plurality of the water manifold rings arranged in series along the barrel.

[0023] In one form, the handpiece further comprises a converging nozzle at the outlet to the barrel.

[0024] In one form, the handpiece further comprises a barrel portion through which the barrel extends, and a pistol grip portion comprising a trigger.

[0025] In one form, the pistol grip portion comprises a connection fitting in a butt thereof via which the water hose can be connected to the handpiece.

[0026] In one form, the pistol grip portion comprises a water flow control valve which is actuated by the trigger to control water supply to the handpiece. [0027] In one form, the pistol grip portion comprises a switch which is actuated by the trigger to control dry mix supply to the handpiece.

[0028] In one form, a portion of the barrel preceding the outlet defines a serpentine path therethrough. [0029] In one form, said portion of the barrel comprises a plurality of baffles space apart therealong.

BRIEF DESCRIPTION OF DRAWINGS

[0030] Embodiments of the present invention will be discussed with reference to the accompanying drawings wherein:

[0031] Figure 1 is a front isometric view of a powder spray pump;

[0032] Figure 2 is a side isometric view of the powder spray pump of Figure 1;

[0033] Figure 3 is rear view of the base and the workings from the powder spray pump of Figures 1 and

2;

[0034] Figure 4 is a front view of the base and the workings;

[0035] Figure 5 is an underside view of the base;

[0036] Figure 6 is an underside view of the base with a cover removed to permit visibility of a gearbox; [0037] Figure 7 is an isometric view of a rotor from the powder spray pump;

[0038] Figure 8 is a plan view of the rotor;

[0039] Figure 9 is a cross-sectional view through the rotor;

[0040] Figure 10 is an exploded isometric view of a handpiece for the powder spray pump;

[0041] Figure 11 is an exploded cross sectional view through the handpiece;

[0042] Figure 12 is a detail exploded cross sectional view through the handpiece;

[0043] Figure 13 is a schematic diagram of the workings for the powder spray pump;

[0044] Figure 14 is a flow control diagram of the workings for the powder spray pump; [0045] Figure 15 and 16 are isometric views of a hose coupling for the powder spray pump; and

[0046] Figure 17 is a cross-sectional view taken lengthwise through the hose coupling of Figures 15 and 16.

[0047] In the following description, like reference characters designate like or corresponding parts throughout the figures.

DESCRIPTION OF EMBODIMENTS

[0048] Referring now to Figure 1, where there is illustrated a powder spray pump 1 comprising a base 2, and an enclosed hopper 4 sitting atop the base 2. In use, the powder spray pump 1 receives a dry mix via the hopper 4, entrains this in an airstream and issues this under pressure via an outlet O to a dry mix hose 6 and a handpiece 100 in turn. Simultaneously, the powder spray pump 1 receives water from a water supply and issues this under pressure via a water outlet to a water hose 8 and the handpiece 100 in turn, for mixing with the dry mix at the handpiece 100.

[0049] The hopper 4 comprises an uppermost opening equipped with a hatch 10 for closing and sealing the opening so that dust cannot escape. The hopper 4 can be refilled via this opening, and the opening closed using the hatch 10 when the refilling operation is concluded. The hopper 4 is sized to contain a significant amount of the dry mix material (6 tonnes in the case of the illustrated embodiment), so that it would only need reloading occasionally, and certainly need not be loaded in a continuous manner (such as by conveyor) like some powder spray pumps of the prior art. These features significantly reduce the dust emanating from the hopper 4 when the powder spray pump 1 is in use.

[0050] The hopper 4 further comprises a lower opening equipped with a hatch 11 at the bottom thereof. This lower opening can be used for cleaning and maintenance purposes.

[0051] To one side of the hopper 4, the base 2 comprises a housing 12 for pump workings, where the housing 12 comprises a fascia panel 14 comprising a control panel for the powder spray pump 1. To one side of the housing 12, there is a holster 16 for the handpiece 100, and to the other side of the housing 12 there is space for stowing the dry mix hose 6 and the water hose 8.

[0052] Extending about the base 2 is a protective framework 18 to protect the housing 12, and more particularly the pump workings housed therein. This protective framework 18 is fabricated from tubular steel, and forms a perimeter for the base 2. A similar protective framework 20 extends about the top of the hopper 4 to protect this from damage. [0053] The base 2 further comprises a parallel, spaced apart pair of rectangular hollow section steel channels 22 for receiving the tines of a forklift, so that the powder spray pump 1 can be lifted and moved.

[0054] In use, a supply of compressed air is connected to an air inlet AI for the spray pump 1. The pump workings comprise a pneumatic motor 30. The pneumatic motor 30 receives compressed air from the air inlet AI via an air filter 32 and a process valve 34, and in turn, this pneumatic motor 30 drives further workings, including a rotor 60 in the hopper, and a water pump 40, via a gear train 45 in a gearbox 46 in the bottom of the base. In this way, a relationship (i.e. proportionality) is established between the air flow rate issuing from the pneumatic motor and the speed of the rotor 60, and thus the rate of its supply of dry mix in turn. Similarly, a relationship is established between the air flow rate and the speed of the water pump 40, and thus the rate of its supply of water in turn. This relationship assists to maintain the consistency of powder spray throughout all phases of operation, including start up and shut down.

[0055] Exhaust air from the pneumatic motor 30 is directed to a collector 50 in the hopper, which is suspended over a portion of the rotor 60.

[0056] Also suspended over the rotor 60, but not illustrated, is an inverted cone, which prevents the weight of material above the rotor 60 bearing directly thereon and thereby impeding its operation, but which permits material to pass beneath its edge to the rotor 60.

[0057] The collector 50 comprises a body forming an extractor hood over the rotor. This body comprises a top plate 52, and a skirt 54 extending down from the top plate 52 and terminating j ust clear of the face of the rotor 60. To the top plate 52 of the collector body there is secured an inlet manifold 56 comprising a plurality of outlets, each of which issues a downwardly directed jet of air into the collector 50.

Extending from the side skirt 54 to the outlet O for spray pump is an outlet line 58.

[0058] With reference to Figures 7 through 9, it can be seen that the rotor 60 comprises a disc shaped body with a recessed channel forming a ring extending around an outside of a face of the disc, where the channel is divided into a series of segments by a series of radially extending vanes 62, so that each segment forms a scoop 64. In use, as the rotor 60 turns it will collect material in the scoops 64 and deliver this to the collector 50.

[0059] In use, compressed air from the pneumatic motor 30 is issued in the collector 50 as a plurality of air jets directed at the rotor 60, agitating material carried on the rotor 60 so that this forms a dust which is retained in the collector 50, and which becomes entrained in an airstream which flows to the outlet O, through the hose 6 and on to the handpiece 100 in turn. [0060] This interaction of the rotor 60 and the collector 50 ensures effective clearing of the hopper 4, prevents bridging of plaster and ensures successful flowing of material. It also allows for accurate control of water plaster ratios mixed at the handpiece 100.

[0061] In use, a supply of water is connected to a water inlet WI for the spray pump. The water pump 40 receives water from the water inlet via a water filter 42, and issues this under pressure to a water pump accumulator 44 and then onto a water outlet for delivery via the water hose 8 to the handpiece 100. The water pump 40 meters water flow rate according to a dry mix flow rate so as to maintain a desired water to dry mix ratio for all dry mix flow rates.

[0062] With reference to Figures 10 through 12, it can be seen that the handpiece 100 comprises a barrel portion 102 and a pistol grip portion 104 comprising a trigger 107. This arrangement provides improved ergonomics compared with arrangements of the prior art, which typically comprise a basic tubular nozzle lacking anything resembling a handle.

[0063] The barrel portion 102 is elongate and comprises a barrel 106 passing lengthwise therethrough from an inlet 106i to an outlet 106o. The inlet 106i comprises a connection fitting 108 via which the dry mix hose 6 can be connected to the handpiece 100.

[0064] The pistol grip portion 104 further comprises a connection fitting 1 10 in a butt thereof via which the water hose 8 can be connected to the handpiece 100. The trigger 107 controls both a water flow control valve (a spool valve in this case) 112 and a pressure switch located in the pistol grip to activate and deactivate dry mix supply to the hand piece 100. The trigger 107 is further linked to an operator presence control or‘dead man’s’ switch which will shut off the pump 1 if the operator becomes incapacitated.

[0065] The pistol grip portion is connected to a barrel body 120, which is generally tubular. To an inlet end of the barrel body 120 there is connected the connection fitting 108, and to an outlet end of the body there is connected a barrel extension assembly 130.

[0066] Inserted into the barrel body 120 is a plurality (3 in the case of the embodiment illustrated) of water manifold rings 122, 124 and 126 arranged in series along the barrel. Together, these rings form a portion of the barrel. In use, each of these manifold rings receive water from the water control valve in the pistol grip portion 104, and distribute and inject this water into the barrel 106 at a plurality of points around an internal circumference thereof.

[0067] With reference to Figure 12, it can be seen that in order to facilitate release of water in the aforementioned manner, each manifold ring 122, 124 and 126 comprises a plurality of equispaced passageways 128 extending therethough in a lengthwise direction of the barrel. The lengthwise extending passageways 128 in each of the rings are aligned so that water can be passed along the barrel between these. Additionally, at the interface between each of the manifold rings 122, 124 and 126 there is provided a circumferentially extending slit, via which the water is released into the barrel 106 and the dry mix flow therethrough.

[0068] A first water manifold ring 122 comprises a water channel 140 extending circumferentially therearound, to receive water from the control valve 1 12, and distribute this to the lengthwise extending passageways 128, which in turn deliver water to a chamfered lip 142 defining one of the release slits, thereby directing water inwardly into the dry mix flow at a relative acute angle (approximately 45° in the illustrated embodiment).

[0069] A second water manifold ring 124 comprises an inlet end inner edge chamfer 144 to complement the chamfered lip 142 on the first water manifold ring 122. Additionally, this also comprises chamfered lip 146 directing water inwardly into the dry mix at a shallower angle than did the first water manifold ring (approximately 30° in the illustrated embodiment).

[0070] A third water manifold ring 126 comprises an inlet end inner edge chamfer 147 to complement the chamfered lip 146 on the second water manifold ring 124. Additionally, this also comprises chamfered lip 148 directing water outward against the barrel wall to prevent build-up of dry mix there.

[0071] Referring now to the barrel extension assembly 130, which comprises a barrel extension tube 150, a plurality of barrel insert segments 160 which are received in the barrel extension tube 150, and, to an outlet end of the barrel extension tube, there is connected an outlet nozzle 170. These barrel insert segments can be removed from the barrel extension tube 150 for ease of cleaning.

[0072] Each of the barrel insert segments 160 comprises an internal baffle 162, so cooperatively these segments 162 define a non-linear or serpentine flow path therethrough, to reduce the velocity of powder spray and promote further agitation and mixing of the dry mix and the water, thereby reducing dust at the outlet nozzle 170, which is a convergent nozzle to accelerate the powder spray at the outlet.

[0073] In use, the water accumulator 44 activates when the trigger 107 is released, because dry mix flow does not does not stop instantaneously, but water flow will stop almost instantaneously resulting in dry mix dust issuing as the handpiece 100. To prevent this, the water from the accumulator 42 is utilised and mixed with the remaining dry mix in the dry mix hose 6 so that this issues as powder spray and not dust, until the remaining dry mix flow is exhausted. [0074] These features of the handpiece 100 improve the mixing of the dry mix with the water, significantly reducing the amount of dust which emanates at the handpiece 100.

[0075] Referring now to Figures 15 through 17, where there is illustrated a hose coupling 200 for the powder spray pump 1. The hose coupling 200 is an assembly comprising a first spigot 202, a second spigot 204, a first collar 206 and a second collar 208. In use, a first hose (not illustrated) is secured between the first spigot 202 and the first collar 206, and a second hose (not illustrated) is secured between the second spigot 204 and the second collar 208.

[0076] The first and second collars 206 and 208 comprise female (i.e. internal) screw threads via which they can be secured to one of two male (i.e. external) screw threads provided on the second spigot 204. The first spigot 202 comprises a flange 210 which is captured by an internal shoulder 212 in the first collar 206.

[0077] The structure of the hose coupling 200 permits the first and second spigots 202 and 204 to swivel with respect to each other, and so too then can the hoses connected by the coupling 200 swivel with respect to each other. This reduces the likelihood of the hoses twisting or kinking.

[0078] The first and second spigots 202 and 204 comprise matching internal bores, so that they present a near continuous internal bore free of internal obstructions. Moreover, a wall thickness of both of the spigots 202 and 204 is tapered down to be as thin as possible without being prohibitively fragile. In this way, the thickness of the edge presented to the dry mix flow is minimised also, which minimises disturbance to the dry mix flow and helps prevent material build ups at these edges.

[0079] By way of recap, then the powder spray pump according to the present disclosure reduces dust at both the hopper 4 and the handpiece 100. This improves both the safety and the visibility for the operators of this equipment, particularly where the equipment is used in confined spaces, such as found in those applications which are underground or indoors. Moreover, the powder spray pump according to the present invention automatically maintains a desired ratio of water to dry mix, ensuring that the consistency of powder spray is maintained during all stages of operation.

[0080] Throughout the specification and the claims that follow, unless the context requires otherwise, the words“comprise” and“include” and variations such as“comprising” and“including” will be understood to imply the inclusion of a stated integer or group of integers, but not the exclusion of any other integer or group of integers. [0081] The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement of any form of suggestion that such prior art forms part of the common general knowledge.

[0082] It will be appreciated by those skilled in the art that the invention is not restricted in its use to the particular application described. Neither is the present invention restricted in its preferred embodiment with regard to the particular elements and/or features described or depicted herein. It will be appreciated that the invention is not limited to the embodiment or embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the scope of the invention as set forth and defined by the following claims

Claims

1. A powder spray pump comprising an enclosed dry mix storage hopper comprising an upper opening equipped with a hatch for closing and sealing the opening, a rotor positioned low in the hopper, a pneumatic motor driving the rotor and a water pump via a gear train, and issuing an airstream to a collector comprising a body which forms an extraction hood over at least a portion of the rotor, wherein in use, as the rotor rotates it delivers dry mix from the hopper to the collector, which entrains the dry mix in the airstream and issues this via a dry mix outlet for delivery to a dry mix hose and a handpiece in turn, and the water pump issues a stream of water via a water outlet for delivery to a water hose and the handpiece in turn, wherein the water pump meters a water flow rate proportional to a dry mix flow rate so as to maintain a desired water to dry mix ratio for all dry mix flow rates.

2. The powder spray pump of claim 1, further comprising a water accumulator receiving water from the water pump and delivering this to the water outlet.

3. The powder spray pump as in either of the preceding claims, wherein the rotor comprises a disc shaped body with a recessed channel forming a ring extending around an outside of a face of the disc, where the channel is divided into a series of segments by a series of radially extending vanes, so that each segment forms a scoop.

4. The powder spray pump of claim 3, wherein the collector comprises a top plate, and a skirt extending down from the top plate and terminating just clear of the face of the rotor.

5. The powder spray pump as in any one of the preceding claims, wherein the airstream is issued into the collector in the form of at least one air jet directed at the rotor, so as to agitate dry mix carried on the rotor so that this forms a dust which is retained in the collector, and which becomes entrained in the airstream.

6. The powder spray pump as in any one of the preceding claims, wherein the handpiece comprises a body comprising a barrel passing therethrough from an inlet for receiving an airstream entrained dry mix, to an outlet, the barrel further comprising at least one water manifold ring adapted to receive water from the water hose and distribute and inject this water into the barrel at a plurality of points around an internal circumference thereof so as to mix the water with the airstream entrained dry mix.

7. The powder spray pump of claim 6, wherein the handpiece further comprises a plurality of the water manifold rings arranged in series along the barrel.

8. The powder spray pump as in either of claims 6 or 7, wherein the handpiece further comprises a converging nozzle at the outlet to the barrel.

9. The powder spray pump as in any one of claims 6 through 8, wherein a portion of the barrel preceding the outlet defines a serpentine path therethrough.

10. The powder spray pump of claim 9, wherein said portion of the barrel comprises a plurality of baffles space apart therealong.

11. The powder spray pump as in any one of claims 6 through 10, wherein the body comprises a barrel portion through which the barrel extends, and a pistol grip portion comprising a trigger.

12. The powder spray pump of claim 11, wherein the pistol grip portion comprises a connection fitting in a butt thereof via which the water hose can be connected to the handpiece.

13. The powder spray pump as in either of claims 11 or 12 wherein the pistol grip portion comprises a water flow control valve which is actuated by the trigger to control water supply to the handpiece.

14. The powder spray pump as in any one of claims 11 through 13, wherein the pistol grip portion comprises a pressure switch which is actuated by the trigger to control dry mix supply to the handpiece.

15. A powder spray pump comprising an enclosed dry mix storage hopper, a pneumatic motor issuing an airstream to a collector which entrains the dry mix in the airstream and issues this via an outlet to a hose and a handpiece in turn, the powder spray pump further comprising a water pump driven by the pneumatic motor to issue a stream of water via a water outlet for delivery to a water hose and the handpiece in turn, wherein the water pump meters water flow rate proportional to a dry mix flow rate so as to maintain a desired water to dry mix ratio for all dry mix flow rates. t6. The powder spray pump of claim 15, further comprising a water accumulator receiving water from the water pump and delivering this to the water outlet.

17. The powder spray pump as in either of claims 15 or 16, wherein the pneumatic motor drives a rotor positioned low in the hopper and issues an airstream to a collector comprising a body which forms an extraction hood over at least a portion of the rotor, wherein in use, as the rotor rotates it delivers dry mix from the hopper to the collector, which entrains the dry mix in the airstream and issues this to the handpiece.

18. The powder spray pump of claim 17, further comprising a gear train via which the pneumatic motor transmits drive to the rotor and the water pump.