GB2205259A

GB2205259A - Shot blasting machinery

Info

Publication number: GB2205259A
Application number: GB08713102A
Authority: GB
Inventors: Shaun Waddingham
Original assignee: Individual
Current assignee: Individual
Priority date: 1987-06-04
Filing date: 1987-06-04
Publication date: 1988-12-07
Also published as: GB8713102D0

Abstract

A shot blasting machine comprises a feed pipe (10) for directing abrasive (16) from a store (14) to a blast wheel (12). Air is drawn or forced through the feed pipe (10) towards the blast wheel (12) to convey abrasive (16) from the store (14) to the blast wheel (12). The air may be drawn into the feed pipe (10) through inlets at the end 38 of the pipe by the natural fan/turbine effect of the blast wheel (12), or it may be forced through the feed pipe (10) by a turbine fan. <IMAGE>

Description

DESCRIPTION SIOTBLASTING MACHINERY The present invention relates to a method and apparatus for improvements in shot blasting machinery employing the wheel blast principle.

Shot blasting machinery is extensively used for cleaning a wide variety of surfaces including oil rig landing pads, oil refinery storage tanks, ships' decks, airport runways, bus depots, factory floor and motorways. The machinery is available in a variety of sizes to suit the particular application and with a variety of features including seif-reclaimation of the abrasive material, efficient dust collection, a high degree of mobility and a choice of power units, for example, hydraulic or electrical.

Shot blasing machinery commonly works on Ole blast wheel principle in which the abrasive, typically steel abrasive, is thrown towards the surface requiring cleaning by means of a metal blast wheel. The steel abrasive strikes this surface and rebounds into the reclaim chamber of the machinery, where it is stored until it is re-used. The continual blasting of the surface requiring cleani.ng by the steel abrasive provides an effective method of cleaning the surface.

To maintain the effectiveness of this cleaning process the steel abrasive must be introduced to the metal blast wheel in a suitable quantity. At present an impeller is utilised to induce the steel abrasive towards the metal blast wheel.

The method of operation of the shot blasting machinery dictates that component wear will be considerable and in particular those components involved in delivering and blasting the steel abrasive through its work cycle, especially the impeller and metal blast wheel, will suffer very considerable wear.

It iS therefore frequently necessary to carry out maintenance on the components of the shot blasting machine, particularly the impeller and the metal blast wheel, and these two components often require replace-ent is has the disadvantage of increasing the tine length in which the shot blasting machine is inoperable and also increases the cost of maintaining he shot blasting machine in a suitable operational condit.on.

It would therefore be advantageous if a shot blasting machine could be provided with a reduced number of components susceptible to excessive wear and also with components that are less expensive to replace.

In accordance with a first aspect of the present invention there is provided a method for inducing abrasive from a store along a feed pipe, and onto a &commat;; blast wheel of a shot blast machine comprising forcing or drawing air at a velocity sufficient to convey abrasive from said store along said feedpipe in a direction towards said blast wheel.

In accordance with a second aspect of the present invention there is provided a shot blasting machine coluprising a feed pipe for directing abrasive from a -store to a blast wheel, a means for permitting the flow of air through said feed pipe, and means for drawing or forcing air through said feed pipe in a direction towards said blast wheel thereby to convey abrasive from said store to said blast wheel.

Preferably the means for drawing or forcing the air through the feed pipe comprises the blast wheel of the shot blasting machine, wherein the natural fan/ turbine effect of the blast wheel is utilised.

Preferably the blast wheel comprises a plastic blast wheel.

Advantageously the feed pipe is inclined towards the blast wheel.

Advantageously the means for permitting the flow of air through the feed pipe comprises an air inlet located at the end of the feed pipe remote from the blast wheel.

Preferably the store means comprises a storage hopper and advantageously a butterfly valve is located within the feed pipe.

Advantageously the shot blasting machinery further comprises a reclaim chamber, a reclaim chamber head, a refuse/abrasive separator and a dust collector.

The invention is described further hereinafter, by -way of example only, with reference to the accompanying drawing, the single figure of which is a schematic representation of one embodiment of the present invention.

A storage hopper 14 holds a store of steel abrasive 16, and contiguous with the storage hopper 14 is a feed pipe 10 through which the steel abrasive 16 can pass. The feed pipe 10 is inclined towards a plastic blast wheel 12 and when the machine is in operation the feed pipe 10 directs the steel abrasive 16 towards the rapidly rotating plastic blast wheel 12. The plastic blast wheel 12 also acts as a turbine fan and draws air into the feed pipe 10 towards the plastic blast wheel 12 through inlets located at the end 38-of the feed pipe 10 remote from the plastic blast wheel 12. The force of the air passing through the feed pipe 10 induces the steel abrasive through a shot control plate 40 and onto the plastic blast wheel 12 at the '12 o-clock' position.The blades of the revolving plastic blast wheel 12 throw the steel abrasive 16 off in a direction 18 towards the surface 42 requiring cleaning, The brasive rebounds in a direction 22 in head 20 of a reclaim chamber 24 which increases in cross section to top of machine and in addition to any refuse travels in a direction 22 towards a refuse/abrasive separator 44. The steel abrasive returns to the storage hopper 14 and the refuse is removed to a refuse collector via a pipe 46 in a direction 26. The steel abrasive collected in the storage hopper is then ready for.re-use. A butterfly valve 28 controls the movement of the steel abrasive along the feedpipe.

The shot blast machine is movable by virtue of a drive motor 34 and wheels, of which only one, 32, is illustrated. The plastic blast wheel is driven by a drive mechanism 36 and the operation of the machine is controlled from a control panel 30.

The invention is not restricted to the details of the foregoing embodiment. For example, a turbine fan may be separate from the plastic blast wheel 12, and air may be forced and not drat into the feed pipe 10. Also a variety of abrasive materials may be used, for example beads.

Claims

CLADIS

1. A shot blasting machine comprising a feed pipe for directing abrasive from a store to a blast wheel, means for permitting the flow of air through said feed pipe, and means for drawing or forcing air through said feed pipe in a direction towards said blast wheel thereby to convey abrasive from said store to said blast wheel.

2. A shot blasting machine according to Claim 1, wherein the means for drawing the air through the feed pipe comprises the blast wheel of the shot blasting machine, wherein the natural fan/turbine effect of the blast wheel is utilised.

3. A shot blasting machine according to Claim 1, wherein the means for forcing the air through the feed pipe comprises a turbine fan.

Is. A shot blasting machine according to Claim 1, 2 or 3, wherein the blast wheel comprises a plastics blast wheel.

5. A shot blasting machine according to any preceding Claim, wherein the feed pipe is inclined towards the blast wheel.

6. A shot blasting machine according to any preceding Claim, wherein the means for permitting the flow of air through the feed pipe comprises an air inlet located at the end of the feed pipe remote from the blast wheel.

7. A shot blasting machine according to any preceding Claim, wherein a butterfly valve is located within the feed pipe.

8. A shot blasting machine according to any preceding Claim, wherein the shot blasting machine further comprises a reclaim chamber, a reclaim chamber head, a refuse abrasive separator and a dust collector.

9. A method for inducing abrasive from a store along a feed pipe, and onto a blast wheel of a shot blasting machine comprising forcing or drawing air at a velocity sufficient to convey abrasive from said store along said feedpipe in a direction towards said blast wheel.

10. A shot blasting machine substantially as hereinbefore described with reference to the accompanying drawing.

11. A method for inducing abrasvie from a store along a feed pipe, and onto a blast wheel of a shot blasting machine substantially as hereinbefore described with reference to the accompanying drawing.