RU2193455C2 - Mobile unit for repair and reconditioning of parts and members of metalwork under field conditions - Google Patents

Abstract

FIELD: mechanical engineering; land and water transport, oil and gas lines, construction engineering. SUBSTANCE: proposed device includes supersonic flat or taper nozzle for applying powder coat. Device forms two-phase gas-and-dust mixture of required kind at required thermal and gas-dynamic parameters for forming high-quality coats to be applied on defective area. Proposed device enables the operator to manually apply coats of required sizes (in thickness, width and length) both locally and over entire surface of part or member of metalwork without displacement and dismantling. EFFECT: ecologically pure equipment developed on base of low-temperature gas-dynamic method. 2 dwg

Description

 The invention relates to several industries and agriculture (engineering, transport, agriculture, metallurgy, fuel and energy industry, oil and gas industry, etc.), where there is a need to repair or restore the performance of parts, assemblies and elements of metalwork directly on the spot their installation and operation.

 A number of coating devices are known, comprising a powder hopper, a powder dispenser-feeder, a gas heater, and carrier gas supply channels (A.S. 1138429, 1983). The known device has several disadvantages - the main one is that it is mounted permanently in the production room and performs one technological operation, for example, the operation of coating synthesis on the surface of a part moved in space.

 Known devices for applying a gas-dynamic method of coating, containing a chamber for mixing powder and gas followed by a supersonic nozzle, hoppers for filling and storing powder, a powder feeder-dispenser, and a carrier gas supply system (A.S. 1618778, 1991).

 Also known is a cold gas-dynamic coating device comprising a hopper for loading a powder mixture with a metering feeder, a mixing chamber, a spray head associated with the mixing chamber, and a carrier gas supply system.

 The device is characterized in that the feeder-dispenser is made in the form of a supersonic feeder-ejector, and the powder spraying head is made in the form of an annular collector - an annular supersonic nozzle (Patent of the Russian Federation 2089665 from 06.23.95 on "Coating device" according to application 95109772).

 Known devices, due to their focus, have large dimensions, are mounted permanently in the production room to perform a specific technological operation, for example, to apply a protective coating to products of a rolling mill during their manufacture, and cannot be used as portable devices for carrying out work in the field .

 The aim of the present invention is the creation of non-stationary, mobile, portable, small-sized, high-tech, environmentally friendly equipment for repair and restoration of the performance of parts of units and metal structures in the field using a low-temperature gas-dynamic method.

This goal is achieved by the fact that a device for repairing and restoring operability of parts of assemblies and metal construction elements, comprising a pistol-type housing, a container (hopper) mounted on it for loading and storing a powder mixture with a metering feeder, a mixing chamber, a spray head associated with the chamber mixing, and the system for supplying the working carrier gas to the spray head, made in the form of a conical, flat or other type of supersonic nozzle, is mounted:
a) in a mobile (portable) version for manual operation of the operator in hard-to-reach areas of repaired units or structures directly at the place of their operation;
b) in a car body, in a train car, on an all-terrain vehicle chassis or other means of transport for carrying out work in the field in regions with satisfactory travel routes;
c) on board a helicopter or other types of air and other transport (for example, river and sea vessels) in hard-to-reach regions;
d) on board space stations or interplanetary spacecraft, etc.

 In FIG. 1 shows a diagram of the proposed device for repair and restoration of the performance of parts of units and metal structures in the field using the low-temperature gas-dynamic method.

 The proposed device consists (Fig. 1) of a container (hopper) 1 for loading and storing a metal or other kind of powder, a gas-dynamic or mechanical feeder-dispenser of the powder mixture 2, which takes the required flow rate from the tank 1, mixing chamber 3, associated with an accelerating and spraying head 4, made in the form of a gun in order to carry out manual work on part 5.

 The spraying head 4 (Fig. 1) is a gun in shape (Fig. 2), on the handle of which a mixing chamber 3 of carrier gas and powder is mounted, an accelerator 6 of a two-phase mixture, made in the form of a conical, plane or other type of supersonic nozzle for the formation of a supersonic flow, its acceleration to the design speed and delivery to the workpiece or structural member for repair or restoration. The dimensions of the spray head (mixer length, nozzle profile, etc.) are calculated on a computer taking into account friction and heat transfer along the length of the head path.

 On individual modifications of the spray head 4 on the handle of the gun (Fig. 2), in addition to the mixing chamber 3 and accelerator 6, a hopper for filling powder and a batcher for feeding powder into the mixing chamber 3 (not shown in FIG. 2) can be mounted.

 For the formation of a two-phase mixture in the desired ratio of particle mass and carrier gas, as well as the delivery of this mixture to the mixing chamber 3 (figure 2) of the spray head, the device contains two pneumatic systems: system 7 (figure 1) of regulation and feeding 3 working carrier gas and a system 8 (Fig. 1) for regulating and supplying gas to a container 1 and a feeder-dispenser 2. Both systems are connected to a cylinder-receiver 9 for storing the estimated mass of compressed gas. The mixing chamber 3 of the device and the spray head 4 are connected to the feeder-dispenser 2 and the system 7 of regulation and supply of carrier gas with a flexible hose 10.

 The control gas supply and control system 7 includes a shut-off valve, a pressure reducer, a pressure gauge, a check valve, an electro-pneumatic valve, a heater, and a thermocouple (not shown in FIG. 1).

 The gas supply system 8 for operation of the feeder-dispenser 2 includes a shut-off valve, a gearbox, a pressure gauge, a check valve, an electro-pneumatic valve (not shown in FIG. 1).

 The proposed device operates as follows.

 To carry out repair or restoration work using the low-temperature gas-dynamic method, the type of powder or mixture of powders is selected in accordance with the type of material of the part or the functions performed by it in the process (compression, tension, rotation, etc.) and it is poured into hopper 1.

 The device produces a low-temperature gas-dynamic coating method on the surface of parts, assemblies, assemblies, as well as reinforcing steel structures, etc., which require repair or restoration work in the field. As the coating material can be used metals, metal alloys, mixtures thereof, ceramics, cermets (carbides, borides, etc.). The diameter of the powder particles is determined by the density of the powder material and can vary in a wide range - from several microns to several tens of microns.

 In the initial state, the spray head (gun) 4 is in the hands of the operator. Gas flow is formed in the pneumatic systems 7 and 8 (Fig. 1) of the device with the necessary thermodynamic parameters. The powder flow rate is established by the metering feeder 2 and is supplied in the form of a gas suspension to the mixing chamber 3 of the spray head 4 through flexible hoses 10. In the mixing chamber 3 (Fig. 1), the carrier gas delivered from the pneumatic system 7 and the powder suspension from the metering feeder 2 are thoroughly mixed along the length of the mixing chamber 3 (FIG. 2) of the spray head 4, and the resulting two-phase mixture enters the accelerator nozzle 6 of the head 4 (FIG. 2). In accelerator 6, the two-phase mixture moves along the axis, acquiring the calculated velocity at the nozzle exit. Having accelerated in this way, the two-phase flow reaches the surface of the part 5 (Fig. 1) and forms a coating of the required dimensions on its surface. The spray head is moved by the hand of the operator, who controls the process by pressing the electric switch 11 (figure 2), connected by an electric wire 12 to the electro-pneumatic valves of systems 7 and 8 (figure 1). The operator also visually monitors the condition of the coating in the area of repair or restoration of the part.

 The mass flow rate of powder consumed is determined by the technology for repairing the part, its wear, or the degree of damage.

 The temperature of the carrier gas is set in the system 7 (figure 1) in accordance with the need to achieve the estimated particle velocity. Its value is much lower than the melting temperature of the material of the powder particles.

 The proposed device creates a two-phase gas-dust mixture (particles + carrier gas) of the desired kind with the necessary thermo- and gas-dynamic parameters, providing the technology of coating formation and its quality by the low-temperature gas-dynamic method.

 The device allows the operator to manually obtain a coating of a given thickness over the entire surface of the product or locally without moving it, while the surface profile of the product can have any shape and length.

Claims (1)

 A pistol type device with a supersonic nozzle for applying a powder coating, comprising a pistol type housing, a powder-working gas mixing chamber mounted on it, coupled to the nozzle, a powder and working gas supply fitting and a control button, while the supersonic nozzle is conical or flat.

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