A shot blasting machine with an improved liner system

Abstract

A shot blasting machine (100) comprising a liner system (200, 201) arranged to protect the machine in use, the shot blasting machine (100) comprising a blast wheel (910) comprised in a blast chamber (160) delimited by the liner system (200, 201), 5 the liner system comprising: a back wear plate (260) and a front wear plate (270), integrally formed with a body of the shot blasting machine (100) and extending in planes transversal to an axis of rotation of the blast wheel (910), where each wear plate has a respective peripheral edge (410, 420), 10 at least one top liner (210) and at least one side liner (220), arranged to sealingly engage the peripheral edges of the back wear plate (260) and the front wear plate (270), and a plurality of pressing elements (610, 620, 630) arranged to press (F) the at least one top liner (210) and the at least one side liner (220) against the 15 peripheral edges of the back wear plate (260) and the front wear plate (270).

Description

[0001] TITLE

[0002] A SHOT BLASTING MACHINE WITH AN IMPROVED LINER SYSTEM

[0003] TECHNICAL FIELD

[0004] The present disclosure relates to construction equipment for processing hard surfaces such as concrete, asphalt, steel and stone floors. There are disclosed improvements in shot blasting machines and liner systems for use with shot blasting machines.

[0005] BACKGROUND

[0006] It is sometimes desired to remove an upper layer of a hard surface, such as a layer of paint on a concrete floor, e.g., in preparation for refurbishing the surface by adding a new coating material.

[0007] Shot blasting is a process for renovating hard floor surfaces. Shot blasting machines throw a large amount of steel shot at very high speed by centrifugal force at the surface to be processed. After the steel abrasive hits the surface, the shot blaster recycles the media. Dust and contaminants can for instance be removed by an air wash separator and extracted by a dust extractor. This makes the shot blasting process almost dust-free which is an advantage. The process is comparable to sand blasting, but it provides a much more powerful action due to the weight and speed of the metal beads. Since the steel shot is recycled, it is also normally a cost efficient way to remove an upper layer from a hard surface.

[0008] The shot blasting machines themselves are subject to wear from the shots and from the dust generated in use. It is desired to reduce this wear. US 2002 / 0112515 A1 , EP0084430, GB103781 1 , and WO 2017 / 092806 A1 all relate to shot blasting machines with liner systems arranged to protect the machine from self-inflicted wear. However, there is a need for further improvement. SUMMARY

[0009] It is an objective of the present disclosure to provide improved shot blasting machines. This objective is at least in part obtained by a shot blasting machine comprising a liner system arranged to protect the machine in use. The shot blasting machine comprises a blast wheel comprised in a blast chamber delimited by the liner system. The liner system comprises a back wear plate and a front wear plate extending in planes transversal to an axis of rotation of the blast wheel, where each wear plate has a respective peripheral edge, and where at least the back wear plate is fixed to or integrally formed with a body of the shot blasting machine. The liner system also comprises at least one top liner and at least one side liner, arranged to sealingly engage the peripheral edges of the back wear plate and the front wear plate. A plurality of pressing elements is arranged to press the at least one top liner and the at least one side liner against the peripheral edges of the back wear plate and the front wear plate. This way a liner system with minimized gaps is provided that ensures efficient protection against self-inflicted wear by abrasive media and dust particles generated from use of the shot blasting machine. The inner walls of the blast chamber are thus efficiency protected, and the lifetime of the shot blasting machine is extended, which is an advantage. The liner system is easy to install and to service, i.e., liner system components are easy to replace when worn out.

[0010] A thickness of the top liner and / or a side liner optionally exceeds that of the back wear plate and that of the front wear plate. The majority of the wear is normally seen on the liner parts, and thus it makes sense to add thickness here in favour of the wear plates that extend transversal to the rotation axis of the blast wheel or wheels, at least if total weight of the machine and / or material cost is an issue, which it normally is.

[0011] At least a part of the peripheral edge of the back wear plate and at least a part of the peripheral edge of the front wear plate are optionally aligned in direction perpendicular to the axis of rotation of the blast wheel. This way a stable support against which the liner components can be pressed is provided, which is an advantage.

[0012] The front wear plate may be fixed to or integrally formed with a blast chamber access lid of the shot blasting machine. The blast chamber access lid can be made relatively large in this manner, which improves access to the blast chamber. The entire blast chamber lid can also be replaced in a convenient manner in case the front wear plate needs to be replaced due to wear.

[0013] The liner system may also comprise a top plenum liner, a bottom plenum liner, and two side plenum liners arranged to delimit an egress part of the blast chamber. The two side plenum liners can be arranged to sealingly engage peripheral edges of the top and bottom plenum liners, where at least two pressing elements are arranged to press the two side plenum liners against the peripheral edges of the top plenum liner and the bottom plenum liner. This way the egress part of the blast chamber is also efficiently protected in a service-friendly manner. The top plenum liner and the bottom plenum liner can be held in position relative to the shot blasting machine body by fastening elements such as bolts attached to the machine body, to improve the mechanical integrity of the liner system at the egress part of the blast chamber.

[0014] According to some aspects, at least one of the pressing elements comprises a pair of threaded rods extending out from the shot blasting machine body, where a plunger on a center piece of the pressing element is arranged to be pushed into an aperture formed in the machine body by nuts engaging the threaded rods. The plunger can be made in a larger cross-section dimension compared to a bolt or the like, which is an advantage since the pressing force on the liner is better distributed. The pressing force is also improved due to the use of a pair of nuts on respective threaded rods instead of a single nut.

[0015] At least one top liner advantageously extends past the blast wheel in the ingress direction of the shot blasting machine, i.e., a distance down into the blast chamber. This way the impact from the shots become more angled, which reduces the wear on the side liner. The top liner of the liner system is in this case asymmetrical about a center of a curvature portion of the top liner. According to some aspects, the front wear plate comprises at least one reinforcement element extending in direction of the axis of rotation of the shot blasting wheel and arranged along at least a portion of the peripheral edge of the front wear plate. This reinforcement element improves the support provided by the peripheral edge to the liner components pressed there against.

[0016] A sealing compound, such as silicon, can be applied between liner components and / or between liner components and the wear plates to further improve the integrity of the inner wall of the blast chamber. Various sealing compounds can be used for this purpose, but it is an advantage if the sealing compound is a resilient compound that can absorb some movement between the components of the liner system, which movement could otherwise cause gaps between the components to grow in size.

[0017] Shot blasting machines and methods for using shot blasting machines are also disclosed herein. The machines and the methods are associated with the advantages mentioned above.

[0018] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a / an / the element, apparatus, component, means, step, etc." are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated. Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following description. The skilled person realizes that different features of the present invention may be combined to create embodiments other than those described in the following, without departing from the scope of the present invention.

[0019] BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present disclosure will now be described in more detail with reference to the appended drawings, where Figure 1 illustrates an example shot blasting machine;

[0021] Figure 2A-B show two example liner systems;

[0022] Figure 3 schematically shows a liner pressed against a supporting edge;

[0023] Figures 4A-B illustrate details of a shot blaster machine lining system;

[0024] Figure 5 illustrates a body portion of a shot blasting machine;

[0025] Figures 6A-B show details of a shot blasting machine;

[0026] Figures 7A-B show details of a shot blasting machine;

[0027] Figure 8 illustrates a pressing element for pressing on a liner part;

[0028] Figure 9 illustrates a geometry of a shot blasting chamber;

[0029] Figures 10A-B show an example shot blasting machine fixed wear plate;

[0030] Figures 1 1 A-B show another example fixed wear plate; and

[0031] Figure 12 is a flow chart illustrating methods.

[0032] DETAILED DESCRIPTION

[0033] The invention will now be described more fully hereinafter with reference to the accompanying drawings, in which certain aspects of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments and aspects set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout the description.

[0034] It is to be understood that the present invention is not limited to the embodiments described herein and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the appended claims.

[0035] Figure 1 illustrates an example shot blasting machine 100. This machine can be used to remove an upper layer of a surface 120, such as a concrete, steel or stone floor. The machine 100 accelerates small metal balls known as “shot” or steel abrasives by means of a blast wheel in an ingress direction 110 towards the surface 120 to be processed. The impact by the shot on the surface 120 has an abrasive effect. The spent shot together with the particulate matter from the surface is extracted via an egress conduit 130 back to a separator system 140 where the shot is recycled and the particulate matter extracted 150 from the machine, e.g., by a dedicated dust extractor or the like.

[0036] The internal volume where the shots are accelerated towards the surface is referred to as the blast chamber 160. The blast chamber has an ingress part where the shot is accelerated towards the surface 120 and an egress part where the spent shot is collected for recycling. A lid can be opened to inspect the blast chamber and the components therein.

[0037] The steel shot not only abrades the surface 120, but also the machine 100, in particular the inside of the blast chamber 160 where the shot has high kinetic energy. This causes wear on the machine, which of course is undesired. Further wear on the inside of the blast chamber is caused by the high kinetic energy dust particles that are generated during use of the machine. To protect the internals of the shot blasting machine 100 against this self-inflicted wear, a liner system is normally used, comprising a number of shielding components that can be replaced when worn down.

[0038] Figures 2A and 2B illustrate example liner systems 200, 201 of the present disclosure. The liner system 200 on the left is for a single blast wheel machine while the system 201 on the right is for a dual blast wheel machine. A shot blast machine uses abrasive media to abrade the surface 120. The abrasive media is often steel shot as mentioned above, but other forms of abrasive media can also be used, such as pieces of steel wire, and various hard granules. A single blast wheel machine uses only one blast wheel to accelerate the abrasive media, while a dual blast wheel machine uses two counterrotating blast wheels that concentrate the abrasive media on a section of the surface to be processed. The side of the blast wheel from which shot is ejected will be referred to herein as the front side of the blast wheel, while the other side of the blast wheel will be referred to herein as the back side of the blast wheel. The front and back sides of the blast wheel are indicated in Figure 9. The liner systems discussed herein are applicable for both single blast wheel machines and dual blast wheel machines. The example liner systems 200, 201 in Figures 2A-B comprise replaceable top liners 210 and side liners 220 in the ingress part of the blast chamber 160. According to a preferred embodiment the top liner 210 extends further down in the blast chamber on the front side of the blast wheel compared to the back side of the blast wheel. The ends of the top liner 210 are shown as 21 1 and 212 in Figure 2A, and the same principle of asymmetry is seen in Figure 2B. As a consequence, the front side liner is shorter than the back side liner. The dual blast wheel machine liner system 201 also has a center liner 280 which supports the top liners 210 as illustrated in Figure 2B. The center liner 280 is normally bolted to the machine body, e.g., by a bolt through the back wear plate and also by a bolt through the front wear plate.

[0039] The egress part of the blast chamber 160 has one plenum top liner 230, one plenum bottom liner 240, and two plenum side liners 250 as illustrated in Figure 2A and in Figure 2B. The plenum liners 230, 240, 250 are preferably all replaceable, i.e., not permanently attached to the machine body or integrally formed with the machine body.

[0040] In addition to the replaceable liner components 210, 220, 230, 240, 250, there are two wear plates. A back wear plate 260 is arranged on the drive shaft side of the blast wheel or wheels, and a front wear plate 270 is arranged under the blast chamber access lid 601 , 602 (The front wear plate 270 not shown in Figures 2A and 2B, but indicated in Figures 10A-B and 1 1A-B). This blast chamber access lid is considered as part of the machine body herein.

[0041] A replaceable liner component is one that can be removed from the machine without undue burden. A liner component that is releasably pressed into position by a pressing mechanism is replaceable since the pressure can be reduced in order to release and remove the liner component in a convenient manner. A liner component that is held in position by means of a releasable fastening element such as a bolt or the like is also replaceable. A liner component that has been welded or otherwise permanently attached onto a portion of the machine body is per definition not a replaceable liner component.

[0042] It has been realized that gaps between the liner components and / or between the liner components and the fixed wear plates are detrimental to performance of the liner system, since the abrasive shots and dust particles from the surface generated from use of the machine get into the gaps, whereby the liner wear at those locations become more pronounced.

[0043] To improve the performance of the liner system of the shot blasting machine 100, it has been realized that a combination of stationary front and back wear plates and liners that are movable and pressed against peripheral edges of the stationary front and back wear plates provide a liner system with reduced gaps when installed in the shot basting machine, and consequently an increased resistance to wear. The front and back wear plates are fixed to or integrally formed with the shot basting machine body, i.e., stationary during installation of the liner components, and therefore provide a stable support against which the top liner(s) 210 and side liners 220 can be pressed. The front and back wear plates are preferably integrally formed with the machine body, but they can also be bolted to the machine body, or otherwise fixedly attached to the machine body. The important point here is that the wear plates are fixedly attached to the machine body while the liner components are loose and can move as they are pressed up against the peripheral edges of the wear plates. In this respect it is also noted that the plenum top liner 230 and the plenum bottom liner 240 may be referred to as wear plates also, since they are, according to some aspects, fixed to the machine body by bolts 710, 720, as illustrated in Figure 7A.

[0044] Figure 3 illustrates the general principle 300 of pressing a replaceable liner 310 by a pressing force F against the edges of a fixed front wear plate 320 and a fixed back wear plate 330. The liner 310 seals the blast chamber 340 by sealingly engaging the edges of the fixed front and back wear plates 320, 330. This way the gaps 350 between the replaceable liner 310 and the fixed wear plates 320, 330 is reduced to a minimum. It is a particular advantage that the sealing interface between the fixed wear plates 260, 270 and liners follows along an unbroken continuous edge of the wear plates without discontinuities such as the “wear dams” described in the prior art document EP0084430.

[0045] To improve the seal between liner components and between liner components and wear plates, silicon or some other suitable sealing compound can be dispensed in the gaps as the liner system is installed. It is preferred to use an elastic sealing compound that can absorb some movement of the liner system components due to, e.g., vibration and expansion from increased temperature.

[0046] Figure 4A illustrates some details 400 of the proposed liner system in a single blast wheel machine. The back wear plate 260 is seen from direction of the opening in the blast chamber 160, i.e., the place where the metal shot impacts the surface to be processed. Figure 4B is a close-up view of the interface between the side liner 220 and the back wear plate 260. The back wear plate 260 is preferably integrally formed with the machine body and therefore not replaceable, while the side liner is replaceable since it is only held in position by the pressure exerted on it and the resistance by the peripheral edge 410 of the back wear plate 260. The back wear plate 260 may, as mentioned above, also be fixed to the machine body by bolting it to the machine body. The seal between the peripheral edge 410 and the liners can be improved further by the addition of a sealing compound such as silicone or the like. The side liner 220 is arranged to sealingly engage the peripheral edge 410 of the back wear plate 260, i.e., it has a shape matched to the peripheral edge of the wear plate, and the gap G formed between the back wear plate 260 and the side liner 220 is therefore very small and thus better able to resist wear from the metal shot during use of the shot blasting machine 100. The seal at the gap G formed between the back wear plate 260 and the side liner 220 can also be improved if a sealing compound is applied during installation of the liner system. A similar seal is provided by the same side liner 220 against the front wear plate 270 (not shown in Figures 4A and 4B). In the example of Figure 4B, it is also noted that the thickness of the side liner 220 exceeds that of the back wear plate 260. This is generally an advantageous design, since the liner components are subject to more wear from the abrasives compared to the front and back wear plate, because of the direction of the shots hurled from the blast wheel in use. The thickness of the different liner elements in general are advantageously made thicker than the front and back wear plates 260, 270.

[0047] Figure 5 illustrates an example shape of the back wear plate 260. The wear plate 260 has a peripheral edge 410, indicated by the dashed line in Figure 5, which is arcuate 510 in vicinity of the blast wheel aperture (the opening in the wear plate through which the drive shaft for the blast wheel extends) and then extends in a rectangular shape 520 down towards the opening in the blast chamber, away from the blast wheel aperture. The direction of rotation of the blast wheel is indicated by the arrow R. The shape of the front wear plate 270 is the same as the shape of the back wear plate, at least when it comes to the peripheral edge portions where the top liner and the side liners interface with the wear plates to seal the blast chamber.

[0048] The striped arrows in Figure 5 illustrate locations suitable for applying pressure to the replaceable liner elements, i.e., the top liner and the two side liners in this example. These pressure forces F push the liners against the peripheral edges of the front and back wear plates, thereby efficiently sealing the blast chamber with minimized gaps between liners and wear plates.

[0049] To summarize, there is disclosed herein a shot blasting machine 100 comprising a liner system 200, 201 arranged to protect the machine from high kinetic energy abrasives and dust particles in use, i.e., as abrasives are propelled by one or more blast wheels against a surface to be processed, such as a concrete floor, a steel floor, a stone floor, or the like. The shot blasting machine 100 comprises a blast wheel 910 comprised in a blast chamber 160 delimited by the liner system 200, 201. A drive shaft extends from a power source such as an electric motor into the blast chamber where it powers the blast wheel. An aperture for feeding a controlled amount of metal shot into the blast chamber in vicinity of the blast wheel is also provided.

[0050] The liner system which covers the inside walls of the blast chamber to protect it from wear comprises a back wear plate 260 and a front wear plate 270. These wear plates are fixed to or integrally formed with the machine body (including the blast chamber access lid) and extends in planes transversal to an axis of rotation of the blast wheel 910. In the examples illustrated in the drawings, the front wear plate is fixedly attached to the inside of a blast chamber access lid which also comprises the shot feed aperture or apertures through which abrasives are fed into the blast chamber. Since the lid forms part of the shot blast machine, being part of a lid is considered as integrally formed with the shot blast machine.

[0051] According to some aspects, at least a part of the peripheral edge 410, 420 of the back wear plate 260 and of the front wear plate 270 are aligned in direction perpendicular to the axis of rotation of the blast wheel 910. According to some other aspects, the front wear plate 270 is fixed to or integrally formed with a blast chamber access lid 601 , 602 of the shot blasting machine 100.

[0052] Each wear plate has a respective peripheral edge 410, 420. Both the front wear plate and the back wear plate are stable in the sense that they are fixedly attached to the machine body. Hence, the peripheral edges of the wear plates provide stable support for resisting pressure from a liner component pressed up against it. The peripheral edge of a wear plate extends around the wear plate. The thickness of a wear plate is the height of its peripheral edge.

[0053] Both the front wear plate and the back wear plate may be formed in different ways and still support the liner components as they sealingly engage the peripheral edges wear plates 260, 270. For instance, the peripheral edges 410, 420 of the back wear plate 260 and the front wear plate 270 that contact the top liner 210 and the at least one side liner 220 preferably but not necessarily have equal shapes seen along a normal to an extension plane of the wear plate. In the example shown in Figures, both the front wear plate 260 and the back wear plate 270 have U-shaped peripheral edges with parallel legs. In a preferred example, the wear plates extend in parallel planes, and the peripheral edges of the front wear plate and the back wear plate overlap each other when seen from a direction normal to the parallel extension planes of the wear plates.

[0054] Any of the back wear plate 260 and / or the front wear plate 270 may also be shaped as a horse shoe, with a cut-out portion inbetween the peripheral edges 410, 420, or a portion of reduced thickness inbetween the peripheral edges 410, 420.

[0055] The back wear plate 260 and / or the front wear plate 270 can also be formed by a plurality of segments, i.e., a wear plate can be assembled by a plurality of pieces, although it is preferred that the wear plates are integrally formed as a single piece of material. A wear plate need not be of the same material throughput. A different material can be used at the center, such as a material of different hardness.

[0056] At least one top liner 210 and at least one side liner 220 are arranged to sealingly engage the peripheral edges of the back wear plate 260 and the front wear plate 270, and a plurality of pressing elements 610, 620, 630 are arranged to press (with a force F) the at least one top liner 210 and the at least one side liner 220 against the peripheral edges of the back wear plate 260 and the front wear plate 270. This pressure and the sealing engagement of the components of the liner system provides an internal protective covering of the blast chamber without gaps, which is an advantage. It is easy to replace the replaceable the liner components since they are only held in position by the pressure applied by the pressing elements 619, 620, 630. The front wear plate and the back wear plate are not so easily replaced, but this is of little consequence since the wear plates are not subject to significant wear from the abrasives.

[0057] Figures 6A and 6B illustrate the blast chambers of a single blast wheel machine and a dual blast wheel machine with the blast chamber access lids 601 , 602 in place. The liner system 200, 201 may furthermore comprise a top plenum liner 230, a bottom plenum liner 240, and two side plenum liners 250 arranged to delimit an egress part of the blast chamber 160, as illustrated, e.g., in Figures 2A and 2B, and also in Figure 6A and 6B. The two side plenum liners 250 are arranged to sealingly engage peripheral edges of the top plenum liner 230 and the bottom plenum liner 240, and at least two pressing elements 640 are arranged to press the two side plenum liners 250 against the peripheral edges of the top plenum liner 230 and the bottom plenum liner 240. This way the egress portion of the blast chamber, sometimes referred to as the plenum portion of the blast chamber, is protected from wear by a tight liner system with minimized gaps between the liners. The different plenum liners 230, 240, 250 can be easily replaced by simply releasing the pressure exerted by the pressing elements 640, and sometimes also removing bolts through the machine body, whereupon the liner components can be removed.

[0058] Figure 7A and Figure 7B illustrate an example arrangement of pressing elements 610, 620, 630, 640.

[0059] To secure the top plenum liner 230 and the bottom plenum liner 240 in a more stable manner, they can optionally be held in position relative to the shot blasting machine body by fastening elements 710, 720, exemplified in Figure 7A by threaded fastening elements, i.e., bolts.

[0060] Figure 8 shows an example pressing element 800 in more detail. This example pressing element 800 comprises a pair of threaded rods 830 extending out from the shot blasting machine body. A plunger 810 on a center piece 840 of the pressing element is arranged to be pushed into an aperture 820 formed in the machine body by nuts 860 engaging the threaded rods 830. Optional washers 850 are also shown in Figure 8. These washers 850 are preferably locking washers or spring washers. The plunger 810 then engages the liner component which is located at the other side of the aperture 820. By tightening the nuts 860, pressure is applied to the center piece 840 which pressure is transferred to the liner component behind the aperture via the plunger 810. The plunger applies a more controlled amount of pressure, over a larger area on the liner component, compared to if just a bolt had been used. Due to the two rods, more pressure can also be applied compared to is a single bolt had been used as pressure element. Note however that the liner system concepts discussed herein can be used also together with other types of pressing elements, including regular bolts screwed into the machine body.

[0061] Figure 9 schematically illustrates a part 900 of the internal blast chamber 160 in use. A blast wheel 910 is rotated at high speed to hurl metal shot towards the surface to be processed. The rotation of the blast wheel is indicated by the dashed arrow R. Some example shot trajectories are shown as straight dashed arrows. Two interfaces between top liner and side liner are shown. A first interface G1 is located behind the blast wheel, i.e., opposite to the side of the blast wheel from where the shots are expelled. The other interface G2 is further down in the blast chamber, closer to the floor and further away from the blast wheel axis of rotation. This means that the shot strikes this interface G2 at a more acute angle a relative to the liner surface, which reduces the wear on the interface G2 between the top liner 210 and the side liner 220. In other words, the top liner 210 in this example extends past the blast wheel 910 in the ingress direction 1 10 of the shot blasting machine 100 to a point further away from the rotation center of the blast wheel, downstream from the blast wheel 910. The top liner 210 of the liner system in this example is also asymmetrical about a center of a curvature portion of the top liner.

[0062] The resistance of the blast chamber inner walls to wear from the metal abrasives can be reinforced further if reinforcement elements 275 are bolted or otherwise attached to the front wear plate. These reinforcement elements 275 strengthen the liner system and provides a liner system more resistant to warping, which is an advantage. Figures 10A-B and Figures 1 1A-B illustrate example reinforcement element 275. The front wear plate 270 here comprises at least one reinforcement element 275 extending in direction of the axis of rotation of the shot blasting wheel and arranged along at least a portion of the peripheral edge 420 of the front wear plate 270. Figure 12 is a flow chart illustrating a method for installing a liner system 200, 201 in a shot blasting machine 100 to protect the machine in use. The shot blasting machine 100 comprises a blast wheel 910 comprised in a blast chamber 160 delimited by the liner system 200, 201 , as discussed above. The machine also comprises the back wear plate 260 and the front wear plate 270, discussed above, that are extending in planes transversal to an axis of rotation of the blast wheel 910, where each wear plate has a respective peripheral edge 410, 420, and where at least the back wear plate 260 is fixed to or integrally formed with a body of the shot blasting machine 100. The method comprises: installing S1 at least one top liner 210 and at least one side liner 220 to sealingly engage the peripheral edges of the back wear plate 260 and the front wear plate 270, and pressing S3 the at least one top liner 210 and the at least one side liner 220 against the peripheral edges of the back wear plate 260 and the front wear plate 270 by a plurality of pressing elements 610, 620, 630 on the shot blasting machine 100.

[0063] According to some aspects, the method further comprises applying S2 a sealing compound between the at least one top liner 210 and the at least one side liner 220, and / or between a liner 210, 220 and a wear plate 260, 270 peripheral edge.

Claims

CLAIMS1. A shot blasting machine (100) comprising a liner system (200, 201 ) arranged to protect the machine in use, the shot blasting machine (100) comprising a blast wheel (910) comprised in a blast chamber (160) delimited by the liner system (200, 201 ), the liner system comprising: a back wear plate (260) and a front wear plate (270), extending in planes transversal to an axis of rotation of the blast wheel (910), where each wear plate has a respective peripheral edge (410, 420), and where at least the back wear plate (260) is fixed to or integrally formed with a body of the shot blasting machine (100), at least one top liner (210) and at least one side liner (220), arranged to sealingly engage the peripheral edges of the back wear plate (260) and the front wear plate (270), and a plurality of pressing elements (610, 620, 630) arranged to press (F) the at least one top liner (210) and the at least one side liner (220) against the peripheral edges of the back wear plate (260) and the front wear plate (270).

2. The shot blasting machine (100) according to claim 1 , where at least a part of the peripheral edge (410, 420) of the back wear plate (260) and of the front wear plate (270) are aligned in a direction perpendicular to the axis of rotation of the blast wheel (910).

3. The shot blasting machine (100) according to claim 1 or 2, where the front wear plate (270) is fixed to or integrally formed with a blast chamber access lid of the shot blasting machine (100).

4. The shot blasting machine (100) according to any previous claim, where the liner system (200, 201 ) further comprises a top plenum liner (230), a bottom plenum liner (240), and two side plenum liners (250) arranged to delimit an egress part of the blast chamber (160),where the two side plenum liners (250) are arranged to sealingly engage peripheral edges of the top plenum liner (230) and the bottom plenum liner (240), and where at least two pressing elements (640) are arranged to press (F) the two side plenum liners (250) against the peripheral edges of the top plenum liner (230) and the bottom plenum liner (240).

5. The shot blasting machine (100) according to claim 4, where the top plenum liner (230) and the bottom plenum liner (240) are held in position relative to the shot blasting machine body by fastening elements (710, 720).

6. The shot blasting machine (100) according to any previous claim, where at least one of the pressing elements (610, 620, 630, 640, 800) comprises a pair of threaded rods (830) extending out from the shot blasting machine body, where a plunger (810) on a center piece (840) of the pressing element is arranged to be pushed into an aperture (820) formed in the machine body by nuts (860) engaging the threaded rods (830).

7. The shot blasting machine (100) according to any previous claim, where at least one of the pressing elements (610, 620, 630, 640, 800) is arranged to press upon a gap (G2) between two liner components (210, 220) of the liner system.

8. The shot blasting machine (100) according to any previous claim, where a top liner (210) extends past the blast wheel (910) in the ingress direction (1 10) of the shot blasting machine (100).

9. The shot blasting machine (100) according to any previous claim, where a top liner (210) of the liner system is asymmetrical about a center of a curvature portion of the top liner.

10. The shot blasting machine (100) according to any previous claim, where the front wear plate (270) comprises at least one reinforcement element (275) extending in direction of the axis of rotation of the shot blasting wheel and arranged along at least a portion of the peripheral edge (420) of the front wear plate (270).11 . The shot blasting machine (100) according to any previous claim, where a thickness of the top liner (210) and / or a side liner (220) exceeds that of the back wear plate (260) and that of the front wear plate (270).

12. The shot blasting machine (100) according to any previous claim, where the shot blasting machine is a dual blast wheel machine, where the liner system (201 ) further comprises a center liner (280) arranged to support first and second top liners (210).

13. The shot blasting machine (100) according to any previous claim, where an interface between two liner components of the liner system, and / or an interface between a liner component and a wear plate, comprises a sealing compound.

14. The shot blasting machine (100) according to any previous claim, where the peripheral edges (410, 420) of the back wear plate (260) and the front wear plate (270) that contact the top liner (210) and the at least one side liner (220) have equal shape seen along a normal to an extension plane of the wear plate.

15. The shot blasting machine (100) according to any previous claim, where the peripheral edges (410, 420) of the back wear plate (260) and the front wear plate (270) that contact the top liner (210) and the at least one side liner (220) are U-shaped, where the legs of each U-shape are parallel.

16. The shot blasting machine (100) according to any previous claim, where the back wear plate (260) and / or the front wear plate (270) is shaped as a horse shoe, with a cut-out portion inbetween the peripheral edges (410, 420), or a portion of reduced thickness inbetween the peripheral edges (410, 420).

17. The shot blasting machine (100) according to any previous claim, where the back wear plate (260) and / or the front wear plate (270) is formed by a plurality of segments.

18. A method for installing a liner system (200, 201 ) in a shot blasting machine (100) to protect the machine in use, the shot blasting machine (100) comprising a blast wheel (910) comprised in a blast chamber (160) delimited by the liner system (200, 201 ), a back wearplate (260) and a front wear plate (270), extending in planes transversal to an axis of rotation of the blast wheel (910), where each wear plate has a respective peripheral edge (410, 420), and where at least the back wear plate (260) is fixed to or integrally formed with a body of the shot blasting machine (100), the method comprising: installing (S1 ) at least one top liner (210) and at least one side liner (220) to sealingly engage the peripheral edges of the back wear plate (260) and the front wear plate (270), and pressing (S3) the at least one top liner (210) and the at least one side liner (220) against the peripheral edges of the back wear plate (260) and the front wear plate (270) by a plurality of pressing elements (610, 620, 630) on the shot blasting machine (100).

19. The method according to claim 18, further comprising applying (S2) a sealing compound between the at least one top liner (210) and the at least one side liner (220), and / or between a liner (210, 220) and a wear plate (260, 270) peripheral edge.

Images