Wet blasting machines

Abstract

A wet blast machine for cleaning or preparing surfaces comprises: a treatment source for providing a pressurised mixture of treatment material; a nozzle, the nozzle comprising: an inlet for receiving the pressurised mixture of treatment material; an outlet for ejecting the pressurised mixture; and at least one hole in a wall of the nozzle, the hole for feeding one or more products into the nozzle such that one or more surfaces of the product are exposed to the treatment material whilst within the nozzle, allowing for a more efficient wet blast of the products.

Claims

1. A wet blast machine for cleaning or preparing surfaces of at least one product, said machine comprising: a treatment source for providing a treatment material, comprising a treatment pipe for providing the treatment material to a plurality of nozzles, the treatment pipe comprising a treatment bore, wherein each nozzle extends from the treatment pipe such that a nozzle inlet of each nozzle is in fluid communication with the treatment bore; a pressurized air source for pressurizing the treatment material; a plurality of pressurized air inlet pipes extending from the treatment pipe, each air inlet pipe comprising an air bore in fluid communication with the treatment bore and a respective one of the plurality of nozzles, for diverting a portion of the pressurized mixture of treatment material into the nozzle through the inlet of the nozzle, wherein each nozzle comprises: a central longitudinal axis; a plurality of internal diameters along the central longitudinal axis such that the nozzle has a non-uniform internal diameter along its longitudinal axis; the nozzle inlet for receiving the pressurised mixture of treatment material; an outlet for ejecting said pressurised mixture; and at least one hole in a wall of the nozzle, said at least one hole for feeding the one or more products into one of the plurality of nozzles at an angle relative to the central longitudinal axis of the nozzle such that the surfaces of the at least one product are exposed to the treatment material whilst within the respective nozzle, and wherein the at least one hole is in a portion of the nozzle such that the one or more products are exposed to the treatment material at a maximum flow velocity of the treatment material.

2. The machine of claim 1, wherein the longitudinal central axis of the nozzle is substantially perpendicular to a longitudinal central axis of the treatment bore.

3. The machine of claim 1, wherein a respective longitudinal central axis of each of the air bores is substantially perpendicular to a longitudinal central axis of the treatment bore and wherein each longitudinal central axis of each respective air bore is axially aligned with the respective longitudinal central axis of each of the plurality of nozzles.

4. The machine of claim 1, wherein an internal. diameter of the treatment bore is larger than an internal diameter of the plurality of nozzles.

5. The machine of claim 1, wherein a flow velocity of treatment material through at least one of the nozzles is greater than the flow velocity of treatment material through the treatment pipe.

6. The machine of claim 1, wherein at least one hole guides at least one product transverse to a longitudinal central axis of the nozzle.

7. The machine of claim 1, wherein the at least one hole comprises a pair of holes, said pair being provided substantially perpendicular to the longitudinal central axis of the nozzle aligned along an axis that intersects the longitudinal central axis of the nozzle.

8. The machine of claim 1, wherein the at least one hole comprises a pair of holes, said pair being provided at an angle relative to the longitudinal central axis, that is preferably between 60 and 120 degrees.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments will be described, by way of example only, with reference to the drawings, in which

(2) FIG. 1 illustrates a prior art vapour blast device;

(3) FIG. 2 illustrates an exploded view of part of the vapour blast device of FIG. 1;

(4) FIG. 3 illustrates a nozzle;

(5) FIG. 4 illustrates an alternative embodiment of a nozzle;

(6) FIG. 5 illustrates an alternative embodiment of a nozzle;

(7) FIG. 6 illustrates an alternative embodiment of a nozzle;

(8) FIG. 7 illustrates an alternative view of the nozzle of FIG. 6;

(9) FIG. 8 illustrates an example blast gun utilising a nozzle as shown in FIG. 5;

(10) FIG. 9 illustrates an alternative example of the blast gun of FIG. 8;

(11) FIG. 10 illustrates a vapour blast device utilising a nozzle as shown in FIG. 3 or FIG. 4; and

(12) FIG. 11 illustrates an alternative vapour blast device.

DETAILED DESCRIPTION

(13) It should be noted that the Figures are diagrammatic and not drawn to scale. Relative dimensions and proportions of parts of these Figures have been shown exaggerated or reduced in size, for the sake of clarity and convenience in the drawings. The same reference signs are generally used to refer to corresponding or similar feature in modified and different embodiments.

DETAILED DESCRIPTION

(14) FIG. 1 shows a vapour blast device 100, such as a vapour blast gun for ejecting a pressurised mixture of treatment material (typically abrasive material) and a gas such as air. A typical device 100 is described in detail in GB2065514A. Briefly, however, the device 100 generally comprises a body 110 into which a treatment material such as a slurry (typically comprising an abrasive and water) 120 and a pressurised gas, such as compressed air, 122 are provided and mixed in a mixing chamber 124 to form a pressurised slurry 112. Ducts 126 provide the material 120 and the gas 122 into the mixing chamber. The ducts may enact a rotational angular momentum to the material and gas to create a vortex spun slurry. The mixing chamber is generally formed of one piece moulding from tough material such as metal or high grade plastic. Disposed within the body is a nozzle 130. In the conventional blast device 100, shown in FIGS. 1 and 2, such nozzle acts to direct the pressurised slurry 112 from an inlet 132 of the nozzle towards an outlet 136 via a central passageway or bore 134. The bore 134 may be narrower than the inlet 132 and outlet 136. The narrower bore 134 and expansion of the pressurised gas combine to increase the velocity of the pressurised slurry 112.

(15) The slurry 112 is then directed in a coned outlet or blast stream 140 towards a wire 150 or other surface to be treated. In the example shown, the distance d between the wire 150 and the outlet 136 can be controlled, together with the relative angle between the incident surface of the wire 150 and the nozzle outlet 136. The vapour blast device 100 can also be moved laterally along the direction x to treat other sections of the wire 150 and/or the wire may be passed in front of the stream 140. In some embodiments, the blast stream 140 may have substantially parallel sides to avoid a dispersion of power due to a diverging stream. The blast stream 140 may typically have a circular cross-section.

(16) FIG. 2 shows an exploded view of the device 100 of FIG. 1. In addition to the elements described in FIG. 1, the components for supplying the treatment material 120 and the pressurised gas 122 are shown. Each is supplied by connectors 160, 162 that couple hoses 170, 172 to the body 110 with hose clips 164, 166 or other means.

(17) FIG. 3 shows a cross-sectional view of a nozzle according to the present disclosure. Such nozzle 230 is configured to receive an incident pressurised slurry or treatment material 212 supplied by means such as described above. The nozzle 230 comprises a frustoconical inlet 232 that tapers from the exterior of the nozzle 230 towards a bore 234 provided through the nozzle.

(18) The bore 234 extends generally centrally and parallel to the major axis of the nozzle 230 from the inlet 232 to an outlet 236. The walls 286 of the bore 234 (i.e. the walls of the nozzle) contain a plurality of holes 280a-e, 282a-e that act to guide wires 250a-e through and perpendicular to the bore 234 to expose the wires 250a-e to the pressurised treatment material 212. In the example shown, entry holes 280 and exit holes 282 are provided. The entry and exit holes are aligned. It may be appreciated that the holes may not align or may align in a different manner, such as across a chord of the nozzle 230. Five wires 250 are shown in FIG. 3, although it can be appreciated that any number of wires may be treated by the single incident pressurised treatment material 212 at once, subject to space within the nozzle 230 and the diminishing blast effect along the nozzle as the blast stream 140 decelerates.

(19) Also provided on the external wall 286 of the nozzle 230 are features to couple the nozzle 230 to a vapour blast device 100 such as shown in FIG. 1.

(20) FIG. 4 shows an alternative embodiment of the nozzle of FIG. 3. In this embodiment, the holes 290a-d, 292 a-d are provided at an angle of approximately 45 degrees relative to the perpendicular axis of the bore 234 of the nozzle 230. Entry 290 and exit 292 holes are again aligned to allow wires 250 to pass through the bore to be exposed to the stream of pressurised treatment material 212 flowing through the nozzle 230.

(21) FIG. 5 shows an alternative nozzle. A nozzle 330 is provided that is attachable to a blast gun (see below for details) using an attachment member and/or a shaped protrusion or the like (not shown). The nozzle generally comprises an elongate, typically tubular piece of metal or other material with a high wear resistance.

(22) Nozzle 330 comprises an inlet 332, similar to inlet 232, for receiving a pressurised treatment material. Nozzle 330 further comprises a bore 334 in communication with the inlet 332, similar to bore 234. In contrast to bore 234, however, bore 334 comprises an enlarged section 338. The diameter of the bore in the enlarged section 338 is greater than the diameter of the bore in the non-enlarged section. Holes 380, 382, similar to holes 280, 282, pass through the walls of the nozzle 330 in the vicinity of the enlarged section 338. A product 350 passing through the holes 380, 382 therefore passes through the bore 334 in the enlarged section 338.

(23) Holes 380, 382 may be aligned along a perpendicular axis of the bore 334, as for nozzle 230 in FIG. 3, or provided at an angle relative to the perpendicular axis of the bore 334. In particular, the holes 380, 382 may be provided at an angle of approximately 45 degrees (e.g. between 40 degrees and 50 degrees) relative to the perpendicular axis of the bore 334, similar to nozzle 230 shown in FIG. 4.

(24) A pressurised treatment material may be injected into the inlet 332, and be forced along the bore 334 towards a product 350 that is being fed through holes 380, 382. The enlarged section allows the treatment material to pass around the product 350, so that the product 350 may be more effectively and efficiently treated.

(25) Nozzle 330 may comprise a series of enlarged sections 338, and a plurality of pairs of holes 380, 382. Each pair of holes 380. 382 may enter the bore 338 in the vicinity of an enlarged section 338. Nozzle 330 may thus be used to treat a plurality of products 350 at once, similar to nozzle 230 above.

(26) In particular examples, the diameter of the bore 334 in the non-enlarged section may be relatively thin, for example 2-5 mm in diameter. In such cases, the blast gun 100 may not be suitable for injecting treatment material into the nozzle, as it may cause a blockage in the bore 334.

(27) FIG. 6 shows an alternative embodiment of a nozzle. Similar to the embodiment of FIG. 3, the walls of the bore of the embodiment of FIG. 6 comprise a plurality of holes 480a,b and 482a,b, which are perpendicular to the bore 434. In the illustrated view of FIG. 6, only holes 480a,b and 482a,b are visible, but the nozzle may comprise further holes (as shown, for example, in the nozzle of FIG. 7). In contrast to the embodiment of FIG. 3, each pair of holes 480a,b and 482a,b is aligned along an axis that does not intersect with the central axis of the bore 434. For example, if the bore has a substantially circular cross-section, each pair of holes 480a,b, 482a,b may be aligned along a chord of the circular cross section that is not the diameter of the circular cross-section. Although only holes 480a,b (and 482a,b) are shown, it can be appreciated that the number of holes 480, 482 can be tailored to the intended use and may vary according to the length of nozzle 430 used and the thickness of the wire 450 (or product) processed.

(28) FIG. 7 shows an alternative view of the nozzle of FIG. 6. In this embodiment, the walls of the bore comprise a plurality of holes 480a-u, 482a-u. Each pair of holes 480a-u, 482a-u is displaced from neighbouring pairs of holes 480a-u, 482a-u, so that the pairs of holes 480a-u, 482a-u are arranged in two rows along the length of the nozzle. In the illustrated view, only holes 482a-u are visible. Holes 480a-u are on the other side of nozzle 430. Accordingly, each pair of holes 480a, 482a, 480b, 482b 480u, 482u perpendicularly bisect the bore of the nozzle 430 to expose a portion of the wire or product 350 to the blast stream. It may be considered that each portion of the wire bisects the nozzle along a chordal length.

(29) In other embodiments, the holes may be arranged to form a different number of rows along the length of the nozzle. For example, some of the pairs of holes 480a-u, 482a-u may be aligned along an axis that does intersect the central axis of the bore 434, so that the holes form three rows along the length of the nozzle.

(30) An alternative example of a blast gun 500 that may be used with nozzle 330 is shown in FIG. 8. Blast gun 500 may, for example, be termed a micro wire blast gun.

(31) Blast gun 500 comprises a treatment pipe 510 and a pressurised air inlet 520. A nozzle 330 is attached to the treatment pipe 510. The nozzle 330 may be a nozzle as described in relation to any previous figure. Treatment pipe 510 comprises a treatment bore 512 passing through the treatment pipe 510. The diameter of treatment bore 510 is larger than the non-enlarged section of the bore of the nozzle 330. The flow of treatment material through the treatment pipe is continuous, to prevent blockages. The treatment pipe is open ended to maintain the continuous flow, or may be partially open ended controlled by a valve or control orifice.

(32) The nozzle 330 is attached to the pipe 510 such that the inlet 332 of the nozzle is in fluid communication with the bore 512 of the pipe 510. Nozzle 330 therefore extends from the pipe 510. In the illustrated example the nozzle 330 extends substantially perpendicularly from the pipe 510, but in other examples the nozzle may extend at other angles from the pipe 510.

(33) The nozzle 330 may be attached to the pipe 510 for example by a nozzle attachment means (not shown). The nozzle attachment means may for example be a hole extending through the pipe 510 into the bore 512. The nozzle 330 can then be inserted into this hole to place the inlet 332 of the nozzle 330 in fluid communication with the bore 512 of the treatment pipe 410.

(34) The pressurised air inlet 520 also extends from the pipe 510. Air inlet 520 comprises an air bore (not shown) that is in fluid communication with the treatment bore 512 of the pipe 510, and with the inlet 332 (and bore 334) of the nozzle 330. The air inlet 520 is generally aligned with the nozzle 330, so that pressurised air can be injected across the bore 510 and into the nozzle 310.

(35) In use, a treatment material, such as a slurry of treatment material (typically an abrasive) and gas, flows through the bore 512 of the treatment pipe 510, for example under a low pressure. When treatment material is required in the nozzle 330 to treat a product 350, pressurised air is injected through air inlet 520. The pressurised air acts to force some treatment material from the bore 510 into the nozzle 330.

(36) It can be appreciated that this allows the pressure or flow velocity of treatment material within the nozzle 330 to be highly controlled dependent upon the timing, duration and force of the pressurised air injected by the air inlet 520.

(37) In this way, only a small amount of treatment material is injected into the nozzle 330 by the pressurised air from air inlet 520. This aids to avoid blockages in the nozzle 330, particularly where the nozzle comprises a bore having a small diameter.

(38) By regulating the flow of compressed air, the flow of treatment material within the nozzle 330 is similarly regulated. This allows the pressure and flow velocity of the treatment material to be very high, to prevent blockages and to be tailored to the blasting requirements of the application (i.e. different blasting conditions dependent upon the product material, diameter, etc.). Additionally, the flow velocity of treatment material within the treatment pipe can be kept to a lower rate than typically required for blasting, reducing frictional losses within the system.

(39) A plurality of nozzles 330 may be attached to blast gun 500, in order to treat a plurality of products 350 at the same time. FIG. 9 shows an example of blast gun 500 attached to a plurality of nozzles 330.

(40) Each nozzle 330 is attached to the pipe 510 as described above. In the example shown, the nozzles are aligned at an angle of approximately 40 degrees along and relative to the direction of flow of the treatment material within the treatment bore of the treatment pipe 510. The blast gun 500 comprises a separate pressurised air inlet 520 for each nozzle 330. Each air inlet 520 is attached to the pipe 510 as described above, so that the bore of each air inlet 520 is in communication with both the bore 512 of pipe 510, and inlet 322 of its respective nozzle 330. Each air inlet 520 may be used as described above to inject pressurised air into its respective nozzle 520. The pressurised air will also inject some of the treatment material passing along pipe 510 into the nozzle 330 associated with that air inlet 520.

(41) Furthermore, it can be appreciated that each nozzle may be independently controlled to provide a different set of blasting parameters. It may be also envisaged that a product may pass between and through several nozzles, each providing a different blasting function or parameter. Such a system as shown in FIG. 9 provides a more efficient and controllable process for multiple blasting or blasting of multiple products.

(42) Any nozzle described above may alternatively be used with blast gun 500 in place of nozzle 330.

(43) FIG. 10 shows the nozzle 230 used with the vapour blast device 100 described in FIGS. 1 and 2. The entry holes 280, 290 of the type described above with respect to FIGS. 3 and 4 may be provided within a single nozzle to provide alternative treatment angles for wires 250 passing through the bore of the nozzle 230.

(44) FIG. 11 shows an alternative vapour blast device 700 comprising a plurality of nozzles 730a-c, 731a-c. Such a configuration may be useful if, for example, a large number of wires or products require treatment using the described wet blast (or vapour blast) treatment method. It has been discovered that scaling of the nozzle to include a large number of holes 780 in a single blast stream has limits. Once greater than 20 wires require processing, the efficiency of the vapour blast treatment diminishes. To overcome this limitation, the configuration of FIG. 8 has been designed to expose as much of the wire as possible to the high velocity blast stream.

(45) Each nozzle 730a-c, 731a-c may, for example, be a separate vapour blast device 100. Each nozzle 730a-c, 731a-c comprises holes 780, 782, similar to holes 280, 282 described above. Only holes 780 are visible on the nozzles 730a-c, 731a-c shown in FIG. 10. For clarity, holes 780 are not labelled in the figure.

(46) Each nozzle 730a-c is part of a pair of nozzles with a nozzle 731a-c. For each pair of nozzles 730a-c, 731a-c, the holes 780, 782 of the first nozzle 730a-c are aligned with the holes 780, 782 of the second nozzle 731a-c, so that a single wire may pass through the first nozzle 730a-c and the second nozzle 731a-c of a nozzle pair.

(47) In the extended multiwire nozzle shown in FIG. 10, up to 50 wires 750a-c (only 3 shown for brevity) can be processed. The wires 750a-c are presented in a horizontal line separated by approximately 10 mm. The layout shown utilises 3 nozzles, each with a “high velocity section” for 17 wires. The remaining 33 wires can be deviated slightly to pass under/over the low velocity section 740 (where the bore diameter of the nozzles 730, 731 is higher) of adjacent nozzles.

(48) In the illustrated embodiment, a wire 750a is shown passing through nozzles 730b and 731b, whilst wires 750b and 750c pass through nozzles 730c and 731c. Such an arrangement may allow extra cleaning of a wire. The holes 780, 782 may be aligned as described above in any embodiment of a nozzle 230.

(49) As shown in the illustrated embodiment, each nozzle 730a-c, 731a-c comprises a low velocity section 740 that encloses the nozzle along part of the length of the nozzle. Each low velocity section 740 may facilitate movement of a wire through a different pair of nozzles 730a-c, 731a-c to the one which the section 740 is part of. For example, in the illustrated embodiment, wires 750b and 750c pass over nozzles 730a, 731a, 730b, and 731b and are deviated by the wider bore of the low velocity section 740 of the nozzles 730a, 731a, 730b, 731b before being directed to pass through nozzles 730c and 731c. In a preferred embodiment, holes 780, 782 are only located in the high velocity segments of the nozzle 730, 731. Alternatively, rollers or sleeves could be used to deviate the wires 750.

(50) The plurality of nozzles 730a-c, 731a-c may be held together in a frame, such as frame 710. The plurality of nozzles may comprise any number of nozzles.

(51) From reading the present disclosure, other variations and modifications will be apparent to the skilled person. Such variations and modifications may involve equivalent and other features which are already known in the art of vapour blasting, and which may be used instead of, or in addition to, features already described herein.

(52) Although the appended claims are directed to particular combinations of features, it should be understood that the scope of the disclosure of the present invention also includes any novel feature or any novel combination of features disclosed herein either explicitly or implicitly or any generalisation thereof, whether or not it relates to the same invention as presently claimed in any claim and whether or not it mitigates any or all of the same technical problems as does the present invention.

(53) Features which are described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, various features which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination. The applicant hereby gives notice that new claims may be formulated to such features and/or combinations of such features during the prosecution of the present application or of any further application derived therefrom.

(54) For the sake of completeness it is also stated that the term “comprising” does not exclude other elements or steps, the term “a” or “an” does not exclude a plurality and reference signs in the claims shall not be construed as limiting the scope of the claims.