FIELD OF THE INVENTION

Generally the present invention relates to cleaning devices. In particular, the pre- sent invention pertains to air cannons and related methods.

BACKGROUND

A variety of methods are used today for cleaning different industrial applications. Air cannons (also known as air blasters) are known today for cleaning silos, bins and other large volume structures where dirt is built up and where it is difficult to reach by mechanical means. Air cannons are used in a variety of targets especial- ly in industry settings.

However, generally the air cannons known today have a somewhat slow dis- charge (or blast) of air or other gas used in the air cannon. Because of the slow discharge of gas the air cannons known today may not be effective in removing the accumulated dirt from the surface of the target.

The reason for the slow discharge is that most air cannons today comprise a valve assembly for releasing the gas through the outlet. There may be varying valve assemblies in different air cannons but generally the same problem occur. The valve assemblies cause the gas to discharge rather slowly.

Many of the air cannons used today are also fixed solutions that are installed to the target. These solutions may be difficult to move to another target. Even if it is possible, often it may require additional manpower and the process may be slow and cumbersome.

SUMMARY OF THE INVENTION

The objective is to at least alleviate the problems described hereinabove not satis- factorily solved by the known arrangements, and to provide a feasible air cannon. One objective is to increase the discharge pressure of an air cannon. Another ob- jective is to provide a mobile air cannon. A further objective is to provide an ad- justable air cannon, where the height, rotation and/or tilt angle may be adjusted.

The aforesaid objectives are achieved by the embodiments of an air cannon and a method for discharging an air cannon in accordance with the present invention.

The aforesaid objectives are achieved according to the present invention as claimed in claim 1. The aforesaid objectives are achieved according to the present invention as claimed in claim 14.

Accordingly, in one aspect of the present invention an air cannon comprises -a pressure container for pressurizing gas,

-an outlet,

-a fracturing member arranged in the outlet, wherein the fracturing member breaks when the pressure in the pressure contain- er exceeds the breaking point of the fracturing member.

In one embodiment the fracturing member has a breaking point of at least 6 bars of pressure.

In one embodiment the fracturing member is a plastic sheet.

In one embodiment the fracturing member is acrylic glass.

In one embodiment the thickness of the plastic sheet is l-lOmm.

In one embodiment the fractioning member is machined, such as with cuts in the surface of the fractioning member, to facilitate the fractioning of the fractioning member.

In one embodiment hard particles are arranged on the surface of the fractioning member to increase the effect on a target. In one embodiment the pressure container comprises an inlet for filling the pres- sure container.

In one embodiment the outlet comprises at least two parts such that the fracturing member may be arranged between the two parts of the outlet.

In one embodiment the air cannon comprises a movable platform.

In one embodiment the air cannon comprises an adjustable platform, wherein the height of the outlet can be adjusted.

In one embodiment the air cannon comprises an adjustable platform, wherein the tilt angle can be adjusted. In one embodiment the air cannon comprises an adjustable platform, wherein the rotation angle of the outlet can be adjusted.

In one embodiment the air cannon comprises recoil removal means. In one embodiment the recoil removal means comprise at least one or two cylin- ders.

In another aspect of the present invention, a method for discharging an air can- non comprises

-arranging a fractioning member in an outlet of an air cannon,

-filling a pressure container of the air cannon with gas, and

-pressurizing the pressure container until the fractioning member breaks.

In one embodiment

In one embodiment the height of the outlet is adjusted. In one embodiment the tilt angle of the outlet is adjusted. In one embodiment the rotation angle of the outlet is adjusted. The utility of the present invention follows from a plurality of factors depending on each particular embodiment. In some embodiments the discharge pressure of the air cannon may be increased. In some embodiments the air cannon may be mobile. In some embodiments the height, tilt angle and/or rotation angle of the outlet may be adjustable. The discharge may be directed to the target area by ad- justing the height, tilt angle and/or rotation angle

The expression“a number of’ refers herein to any positive integer starting from one (1), e.g. to one, two, or three.

The expression“a plurality of’ refers herein to any positive integer starting from two (2), e.g. to two, three, or four. Different embodiments of the present invention are disclosed in the dependent claims.

BRIEF DESCRIPTION OF THE RELATED DRAWINGS

Next the invention is described in more detail with reference to the appended drawings in which

Fig. 1 illustrates an embodiment of an air cannon in accordance with the present invention.

Fig. 2 illustrates a second view of the air cannon.

Fig. 3 illustrates a side view of the air cannon.

Fig. 4 illustrates a side view of the air cannon in a tilted position.

Fig. 5 illustrates a top view of the air cannon.

Fig. 6 is a flow diagram of an embodiment of a method in accordance with the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Referring to figure 1, the air cannon 100 comprises a pressure container 102 and an outlet 104.

Preferably, the pressure container 102 comprises four connectors 106-112. The first connector 106 is an inlet for filling the pressure container. The second con- nector 108 may be for a safety valve, the third connector 110 may be for a pres- sure gauge and the fourth connector may be for emergency drainage 112. In some embodiments the connectors are half inch connectors. The pressure con- tainer 102 comprises a service/maintenance connector 114 in the rear end. The service connector may be a two inch connector.

Preferably, the pressure container is 10-200 L. In a mobile embodiment the pres- sure container is preferably 10-90 L. In one preferable embodiment the pressure container is a 90 L pressure container. In a fixed embodiment, the pressure con- tainer may be, for example, 100 L, 150 L or 200 L.

Air or other gas from a factory network, or other real estate network, may be uti- lized to fill the pressure container. Alternatively, air or gas compressors may be used to fill the pressure container. The air cannon may utilize air, nitrogen or other suitable pressurized gas. For example, a factory network may provide 6-8 bars of pressure. If the aim is to pressurize the pressure container to 10 bars, the factory network may be utilized until 8 bars and a separate compressor may be used to pressurize from 8 to 10 bars. In some embodiments a nitrogen tank bottle with for example 200 bars may be used through a pressure regulator for pressur- izing the pressure container.

Preferably, a mobile air cannon may utilize 6-20 bars of pressure. More prefera- bly, a mobile air cannon may utilize 6-15 bars of pressure. A fixed air cannon may utilize 6-40 bars of pressure.

The air cannon 100 comprises an outlet 104. The outlet 104 comprises two parts, a base part 116 and an end part 118. The base part 116 is attached to the pressure container 102. The end part 118 may be detached from the base part 116.

The outlet 104 comprises a flange connection 120 for connecting the base part and the end part. A fractioning member 122 is arranged within the flange connec- tion, between the base part 116 and the end part 118. The end part is tightened to the base part so that the fractioning member is pressed in the outlet 104 between the end part and the base part. The end part may be tightened with two wing nuts 124, 126. The outlet 104 comprises a connector 128, such as a Camlock cou- pling, for extending the outlet. Preferably, the outlet is a 4 inch outlet. For example, for a 90 L pressure contain- er, the outlet may be 4-6 inches. A smaller 10 L pressure container may use a 2 inch outlet. A 200 L pressure container may have a 4-12 inch outlet. Preferably, the fractioning member is acrylic glass such as Plexiglas®. Alterna- tively, the fractioning member may be some other plastic sheet material, glass sheet or other suitable material. Preferably, the fractioning member is some brit- tle material fractioning from the pressure. The material selection and the thick- ness of the material may affect the strength of the discharge/blast of the air can- non.

Preferably, the thickness of the fractioning member is 1-10 mm. For example, a 3 mm thick acrylic glass sheet may break in 8 bars of pressure. The pressure and strength of discharge may thus be adjusted depending on the target. For example, in some embodiments a 6 mm thick acrylic glass may be utilized for a stronger discharge.

Additionally, the fractioning member may be machined to facilitate the fraction- ing. For example, cuts may be arranged to the surface of the fractioning member. For example, 0,5 mm deep cuts may be arranged to the surface of the fractioning member. Thus, a machined 6mm fractioning member may fracture in the same pressure as an unmachined 3mm fractioning member. Additionally or alternatively, hard particles such as sand and/or gravel may be ar- ranged to the surface of the fractioning member to increase the effect on the tar- get. The hard particles may be attached to the fractioning member with adhesive bags, for example. The pressure container 102 may be arranged to a platform 130. The platform may be a movable platform. The movable platform may comprise wheels 132. The wheels may be locked so that the platform stays in place. The platform 130 corn- prises a push handle 133 for moving the air cannon. Additionally or alternatively, the platform may be adjustable so that the height of the outlet may be adjusted. For example, the platform may be a mobile scissor lift trolley 134.

Additionally or alternatively, the platform may be adjustable so that the tilt angle of the outlet is adjustable. The top part of the platform may comprise tilt adjust- ment means for adjusting the tilt angle. For example, in some embodiments, the tilt angle may be adjustable with +/- 25 degrees. The tilt adjustment means may comprise a tilt support plate 136, an axis shaft 138 around which the pressure container and/or outlet is tilted, and a locking handle 140.

Additionally or alternatively, the platform may be adjustable for rotating the out- let and/or pressure container. The top part of the platform may comprise rotation adjustment means for adjusting the rotation. In some embodiments, the pressure container and/or outlet may be rotated 90 degrees in both directions. The rotation adjustment means may comprise a rotating plate 142. The air cannon 100 comprises recoil removal means. The recoil removal means may be arranged to the platform 130. The recoil removal means may comprise a recoil base 144. The recoil base 144 may be attached to the platform 130 with a quick release. The pressure container 102 is arranged to the recoil base 144. The pressure con- tainer 102 comprises a first and second support plate 146, 148 with wheels. The wheels may be arranged to the recoil base so that the wheels move within tracks 150, 152 such as U-bars. The support plates may comprise wheels in four cor- ners, for example.

The recoil removal means may comprise two cylinders 154, 156. Preferably, the cylinders are pneumatic cylinders. Alternatively, hydraulic cylinders may be used. The cylinders may be attached from the front end to the support plates 146, 148 and from the back end to the recoil base 144. The support plates with wheels may slide backwards in the tracks and the two cylinders may be configured to decelerate/brake the movement caused by the recoil.

The air cannon 100 comprises supports 158, 160 for stabilizing the structure. A first and second support 158, 160 is attached to the platform. Two brackets 162, 164 may be pulled out from the platform. The brackets comprise threaded plugs

166, 168 that are arranged against the surface below so that the supports stabilize the air cannon. The supports may assist keeping the air cannon in place from the recoil caused by the discharge. The air cannon may be used to clean different targets. For example, the air can- non may be used in different settings in power stations (or power plants). For ex- ample, boilers may be cleaned with the air cannon during operation or when the boiler is not in use. Other target usage for the air cannon may be, for example, fireplaces, superheaters, evaporators, flue gas ducts, various reactor solutions, electrostatic precipitators, various accessory silos and other industrial applica- tions. Figure 6 is a flow diagram of an embodiment of a method in accordance with the present invention.

At method start-up 202, preparatory actions may take place. At 204, a fractioning member is arranged in an outlet of an air cannon. For ex- ample, a sheet of acrylic glass or other plastic material is placed in the outlet. In some embodiments hard particles are arranged on the surface of the fractioning member. At 206, a pressure container of the air cannon is filled with gas. The pressure container may be filled with gas from a factory network and/or a compressor, for example.

At 208, the pressure container is pressurized until the fractioning member breaks. For example, a fractioning member may withstand 8 bars of pressure. The frac- tioning member breaks when the pressure exceeds the breaking point of the frac- tioning member and the air is discharged from the air cannon.

At 210, the height of the outlet is adjusted. In some embodiments the height of the outlet and/or pressure container may be adjusted. This may include adjusting the height of a platform for the pressure container.

At 212, the tilt angle of the outlet is adjusted. In some embodiments, the tilt angle may be adjusted. This may include adjusting the tilt angle of a platform for the pressure container.

At 214, the rotation angle of the outlet is adjusted. In some embodiments, the ro- tation angle may be adjusted. This may include adjusting the rotation angle of a platform for the pressure container.

Steps 210, 212 and/or 214 may take place before steps 204, 206 and/or 208.

At 216, the method execution is ended. Consequently, a skilled person may on the basis of this disclosure and general knowledge apply the provided teachings in order to implement the scope of the present invention as defined by the appended claims in each particular use case with necessary modifications, deletions, and additions.