JPH06206056A - Apparatus for storage and projection of ice sphere - Google Patents

Abstract

PURPOSE: To provide a device for projecting solid particles to a surface without allowing residual matter to remain, thereby treating these particles. CONSTITUTION: The device for storing and projecting ice balls 26 includes a storage tank 2, a projection gun 4 and a compressed air source 6. The hole in the lower part of this tank communicates with an ejection chamber 44, to which agitating blades 36, a screw pump 38, a motor 32 capable of rotating an axial rod 30 having a ball passage closing means 40 and a jack 34 capable of controlling the translation of this axial rod 30 are fixed. This gun 4 is connected to an outlet 58 of the ejection chamber. A trigger 60 having double contactors is attached to this gun and the first contactor thereof controls the air jet and the second contactor controls the jack 34 in order to raise the axial rod 30 and to rotate the motor 32.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates generally to the treatment of a surface to be treated by impacting solid particles which have been projected, fired, sprayed or ejected with pressure. More particularly, it relates to such processing with the assistance of ice balls. The term ice ball refers within the scope of the invention to an object that is solid at low temperatures and sublimates or becomes liquid at normal temperatures, for example ordinary wet or dry ice.

[0002]

Various methods are known for cleaning surfaces by projecting particles with pressure. For example, spraying of other materials such as sandblast, corundum, steel balls or polyethylene balls is used for this purpose.

All of these methods are effective in terms of cleaning action, but suffer from the drawback of occupying a large volume and thus leaving behind a contaminated residue which requires special removal measures.

Because of this, for example, the use of frozen liquid particles, such as ice-ball-shaped water, is of interest to the ice-spheres as they melt and the resulting liquids leave behind mostly solid residues. This is because it evaporates without leaving anything.

However, the use of ice balls for spraying or projecting for the purpose of surface cleaning has hitherto required to produce these ice balls at the point of use or at least not too far from them. So it is causing some problems. Thus, pipe-carrying such spheres significantly increases the energy required to propel them, which is responsible for the pressure drop within the pipe and thus the increased processing cost. It is also known that ice balls, when placed in a container, have a natural tendency to agglomerate or stick to each other under the influence of pressure to form a solid mass, which then cannot be used to project with a gun. . Furthermore, the systems hitherto conceived have been particularly difficult to adjust and use, including those forming the subject of French patent specification 88 05 692 of 28 April 1988.

[0006]

SUMMARY OF THE INVENTION The present invention is capable of storing ice balls and transporting them from their place of production to the place of use, as well as treating them from this storage tank while maximizing fluid flow without sticking to each other. The present invention relates to a device capable of projecting onto a surface.

The storage and projection device is a triple wall (inner, middle and outer) rotating tank for storing these ice balls, the space between the inner wall and the intermediate wall being a cooling liquid gas. A closed container for the interior, the space between the middle wall and the outer wall is filled with a vacuum by an insulating material, said tank is a conical part towards the bottom, then the lower part is opened to reach the ball injection chamber, while The top ends in a cylinder closed by an insulating lid, which lid has a filling orifice and on which a) a mixing or stirring blade in this cone, in the cylinder,
A screw pump with a pitch that counteracts the drop of the sphere due to gravity when rotated, and an axial rod equipped with a means for sealing the passage of the sphere between the cone and the cylinder between them. A motor, and b) the translation of the axial rod along its length can be controlled to displace the sealing means between a lower position for sealing the passages of these balls and an upper position for opening the passages. Jack,
A tank in which is fixed, a gun whose projection is connected to the exit of this injection chamber for projecting these spheres by the action of compressed air, one at low pressure and the other at high pressure. A source of compressed air, the low pressure compressed air being supplied to the inlet of the injection chamber by a first duct and the high pressure compressed air being supplied to the inlet of the gun by a second duct, And a double contact trigger on the gun, the first contact controlling the injection of the low pressure and high pressure compressed air and the second contact being operable after the first contact. And a trigger for controlling a jack for raising the direction bar and rotating the motor.

[0008] The storage device described above has all the means necessary to achieve this end, which consists in being able to spray or project these balls onto the surface to be treated, remote from the place where they were produced. Is equipped with. So this triple walled tank makes it possible to keep these balls protected from heat. It prevents these balls from sticking and clumping together, and while still maintaining the possibility of sealing this passage at the same height as the conical-to-cylindrical seam, these balls are kept in this tank. Means (blades) are provided to stir them so as to advance towards the bottom. A screw pump that rotates in unison with the axial rod rotates to delay these ice balls from advancing from the storage container to the ejection chamber by gravity. Acting in this way, the screw pump provides a descending path for these balls and "fluidizes" them as they enter the injection chamber. It also makes it possible to regulate the flow rate of these ice balls, because the faster the motor rotates, the lower the flow rate of these ice balls.

The injection chamber also has an important function, since the flow of these balls between this tank and the supply line of the gun cannot take place without it. It is the place to adapt the transfer pressure of these balls, which pressure is thus adjusted to a value between 1 and 3 bar in order to take into account the pressure drop due to the length of this supply pipe. You can
According to the present invention, the pressure in the injection chamber is adapted to the length of the gun supply pipe in each usage pattern.

This triple-walled storage tank allows the use of it, for example, by using a system of small wheels or rollers.
It is sized to fit the fact that it is mobile and can be easily transported between the production site where it is packed with ice balls and the projection site where it is projected onto the surface to be cleaned. In addition, the projection gun with the dual contact triggers allows the operator to compress the ball to propel the ball, open the sealing means, and rotate the axial rods that drive both the mixing blade and screw pump. Allows direct and continuous control of air arrival.

According to the invention, the means for sealing the lower part of the storage tank can be of any known form, for example a passage sealing cone or a disc.

[0012]

The device has the advantage that it operates at atmospheric pressure with respect to this reservoir and the transfer and propelling section operates at a pressure (less than 2 bar) which compensates for the pressure drop in these ducts. This makes it possible to solve a serious technical problem and to provide the user with a very meaningful operability of this tube-gun system. The use of this pneumatic motor and jack control device allows it to be installed in all damp factories without any safety concerns. When very high flow rates are required, the quick-fitting collar connection allows the nozzle / gun assembly to be changed in a very short time. The device, with its small wheels, is mobile and has only one high voltage connection to operate. Despite being original, it is not as constrained as conventional sandblasting devices.

[0013]

The present invention will now be described in detail with reference to the accompanying drawings, with reference to non-limiting examples.

This device for storing and projecting ice balls is essentially a triple-walled storage cylinder 2, as can be seen in FIG.
It includes a projection or spray gun 4 and a compressed air source 6.

In the illustrated embodiment, the triple-walled tank 2 is cylindrically conical, made of 1 mm thick stainless steel sheet, and has an internal volume of about 200 liters for storing ice balls. This inner surface is mirror-finished to prevent heat conduction, and is kept at a very low temperature by injecting a cryogenic liquid such as liquid nitrogen into the space between the inner wall 10 and the intermediate wall 12 by a stainless steel plunger tube 8. Is dripping This space is open to the outside by means of vents 14 located at the top of the tank and connecting it to the external atmosphere.

A second space between the intermediate wall 12 and the outer wall 16 allows the assembly to come to ambient temperature as a result of the fact that it is maintained in a vacuum and filled with an insulating material such as polyurethane foam. Insulate from. The inner tank constituted by this wall 10 extends by a conical section 18 and then by a cylindrical section 20 of length 150 mm and diameter of about 50 mm.

At the top, this tank 2 is sealed with a double wall by a lid 22 which is filled with an insulating material. The lid 22 has two orifices, one of which is used for packing ice balls 26 in this tank, and another orifice 28 of about 25 mm diameter controls the motor 32 as well as the longitudinal translation. Allows passage of the axial rod 30 which is connected to a jack 34 for According to the invention, the motor 32 and the jack 3
The assembly of 4 is integral with this lid and can be removed with it simply by lifting. Over its entire conical portion 18, this axial rod 30 has a mixing or stirring blade 36, while on its cylindrical portion 20 it has a screw pump 38, the function of which will be explained below.

Between these two, ie at the inlet of this cylindrical part 20, a sealing means 40 is provided, which, depending on the upward or downward translation of this axial rod 30, causes an ice ball to travel from the upper part of this tank 2 to the screw pump 20. Open and close moving passages. This sealing means may be of any known type, for example a stainless steel disc or a sealing cone.

In the described embodiment, the storage device is mounted on small wheels 42 to ensure its easy transportation.

The extended portion of the inner wall 10 following the cylindrical portion 20 goes out of the tank 2 and communicates with an injection chamber 44, from which ice balls are sent to the spraying or spraying gun 4 by compressed air.

According to the invention, a general compressed air source 6 is provided near the device and has two pressure expansion valves or closed valve systems, as from a single general source. The first 48 supplies air at low pressure, for example 1 to 3 bar, and the second 50 high pressure, for example 3 to 20.
Supply compressed air with bar.

The sphere exiting from the injection chamber 44 is carried to the gun 4 by the transfer duct 52. The latter receives high pressure compressed air from this system 50 by duct 54. In addition, low pressure compressed air from this system 48 is transferred to duct 56.
Is supplied to the inlet of the injection chamber 44 located opposite to the starting point of the duct 52. In this embodiment, the injection chamber 44 is T-shaped and has three holes, the upper hole of which receives the ball transmitted by the screw pump 38, and the lateral hole thereafter receives low pressure compressed air through this duct 56, And its injection hole 58 leads directly to this duct 52 for transferring these balls to the gun 4.

According to one of the very interesting features of the present invention, control of the entire device can be provided by a dual contact trigger 60 on the gun. Thus, when the user pulls the trigger, the action of the first contactor causes the pneumatic control circuit 62 to raise or lower the ducts 54 and 56 used to carry and project the ice balls. When this first contact is actuated and then the second contact is actuated, the control circuit 64, shown in phantom in FIG. 1, also acts on the jack 34, which raises this axial rod 30 to open the hole 40. Let go and lead the ball towards the bottom of this tank 2. This same control circuit 64 starts the pneumatic motor 32 and thus rotates the axial rod 30. as a result,
These ice balls are mixed or agitated by the blades 36 to prevent cross-linking phenomena in the tank and the screw pump 38.
The ice balls so that they travel toward this firing chamber 44 and then through duct 52 to gun 4.

FIG. 2 shows the gun 4 on an enlarged scale, with its body 66 and the injection chamber 68 ending in a nozzle 70 on the axis of the barrel 72 being clearly visible. This high pressure compressed air enters this chamber 68 by a duct 54 and a sphere arrives by a tube 52. FIG. 2 also shows the trigger 60 and dual pneumatic contacts 76, respectively, for actuating the pneumatic circuit and then the assembly formed by the motor 32 and jack 34, as described.

Storage devices of the type described are used for paint removal, deburring of plastic parts, cleaning and degreasing of aircraft engine parts, nuclear decontamination of various materials, and the like.

[Brief description of drawings]

1 is a diagrammatic overall view of the device, showing the triple-walled storage chamber in axial section.

FIG. 2 is a diagram showing the configuration of this projection gun.

[Explanation of symbols]

 2 rotary tank 4 gun 6 compressed air source 10 inner wall 12 middle wall 16 outer wall 18 conical portion 20 cylindrical portion 22 lid 24 orifice 30 axial rod 32 motor 34 jack 36 blade 38 screw pump 40 sealing means 44 injection chamber 52 pipe 54 second Duct 56 1st duct 58 Exit 60 Trigger

Claims (1)

[Claims] 1. A device for transporting ice balls from their production site to the use site where they are projected onto a target without storage sticking, the triple wall (inner, middle and intermediate) for storing these ice balls. The outer) rotating tank (2), the space between the inner wall (10) and the intermediate wall (12) constitutes a closed container for the cooling liquid gas, and between the intermediate wall (12) and the outer wall (16). Space is filled with insulation by vacuum, the tank is conical (18) towards the bottom, then the lower part is opened to reach the ball ejection chamber (44), while the upper part is covered by the insulating lid (22). It ends in a closed cylindrical part (20), whose lid (22) has a filling orifice (24) and a) in this conical part (18) a mixing or stirring blade (3)
6) is a cylindrical portion (20), and a screw pump (38) having a pitch so as to counteract the drop of the sphere due to gravity when rotated
And an axial rod (30) between them with means (40) for sealing the passage of the sphere between the cone and the cylinder.
A motor (32) capable of rotating the shaft, and b) the axial rod (30) for displacing the sealing means (40) between a lower position which seals the passages of these balls and an upper position which opens said passages. A jack (34) capable of controlling translation along its length, a tank to which is fixed, its inlet tube (52) for projecting these balls under the action of compressed air, the outlet of this injection chamber being A gun (4) coupled to (58), a compressed air source (6) supplying air at two pressures, one low and the other high, this low pressure compressed air being fed by a first duct (56) A source of compressed air supplied to the inlet of the injection chamber and the high pressure compressed air supplied to the inlet of the gun by a second duct (54), as well as a double contact trigger (60) attached to the gun. And its first contact is at this low pressure and high A second contact, which controls the injection of compressed air and is operable after the first contact, controls a jack (34) for raising the axial rod (30) and rotating the motor (32). A device comprising a combination of triggers.