RU2157736C2 - Device for application of anticorrosive mastic - Google Patents

Abstract

FIELD: spraying and application of protective coatings. SUBSTANCE: device may be used for application of viscous anticorrosive mastic to machine surfaces. Edge filter of device is positioned in heat-carrier reservoir under tank for mastic. Assembly for supplying compressed air into edge filter for blowing through is made in form of branch pipe with radial holes directed upwards arranged inside filtering cup. Compressed-air supply assembly also includes attachment with moving nozzle positioned on spraying gun. Needle is fixed in mixing channel of attachment by means of pin. Needle is provided with feathering made of plate equal in width to diameter of attachment mixing channel and with point. Needle interacts with moving nozzle hole. Compressed-air outlet from mastic tank is shaped as exhaust branch pipe installed on tank. Exhaust branch pipe is made in form of truncated cone with fine-mesh net of high thermal conductivity secured on its larger base. Threaded groove is provided on surface of filtering cup having longitudinal grooves in which round-section wire is placed. EFFECT: enhanced efficiency and safety. 3 cl, 5 dwg

Description

 The invention relates to devices for spraying and applying protective coatings, can be used for applying viscous anticorrosive mastic on the surface of machines.

 A device for heating and applying anticorrosive mastic is known, which contains a heated tank for mastic, hoses for feeding mastic and compressed air to the spray gun, in which electric heating spirals are placed, connected by ends on one side to each other, and on the other, with a step-down transformer. (RU, application N 95112984/25, IPC: B 05 B 7/16, 07.27.1997).

 The disadvantages of the known device are in violation of its performance in the event of accidental ingress of weeds in the tank and the deterioration of its service conditions when applying exfoliating mastics, as well as when cleaning the supply hose from mastic residues.

 This is due to the fact that the device does not have its own filter element, and because of the high viscosity, it is impossible to filter the mastic when refueling it in the tank. As a result, the spray gun becomes clogged, which leads to interruptions in work and unproductive time spent on cleaning it. In addition, in the known device, the mastic is mixed manually with the lid removed from the tank, and the hose is cleaned of mastic residues by disconnecting the hose from the tank.

 Also known is a slotted wire filter, consisting of a housing, a filter cartridge with a wire wound over the outer surface having a cross section in the shape of a triangle, and a device for cleaning it. (See Volberg B. B. The device and operation of painting and drying units in mechanical engineering. - M .: Higher school, 1982. - S. 177-178).

 The disadvantages of the known filter due to the complexity of the structural design of the device for cleaning the filter cartridge and the low technological reliability of its operation at low temperatures. The complexity of the design of the device for cleaning the filter cartridge is expressed in the presence of an electric motor and gear for turning the cartridge. Low technological reliability is associated with the cooling of the mastic in an unheated filter housing, an increase in its viscosity and resistance, which leads to a decrease and further termination of the supply of mastic through the filter.

The closest known device to the claimed technical essence and the achieved effect is a mounted conservation unit containing a tank for preserving composition, a supply hose of composition and air to the spray gun and a valve connected to them, equipped with a shut-off needle and a check valve, and the shut-off needle is placed in the air channel, and the check valve in the material channel. (See ed. St. USSR N 1816509 Mkl ⁴ V 05 V 13/00).

 The disadvantages of the known device are the limited operational capabilities of the installation when processing hard-to-reach surfaces. This is due to the fact that as a result of connecting the valve to the spray gun, its overall size increases towards the handle. This limits the freedom of movement of the spray gun when applying coatings to hard-to-reach surface areas, for example, to wheel arches of a passenger car. This leads to gaps in the coating and a decrease in the quality of the corrosion protection of the metal.

 Technological failures in the operation of the known device occurring when the needle doesn’t tightly seal the channel through which compressed air penetrates the composition supply hose during coating and causes interruptions in its spraying.

 The complexity of the design of the valve containing the check valve in the material channel.

 The impossibility of a closed purge with compressed air of the spray gun. To carry out this operation on a known device, you must first close the supply valve on the tank, remove the plug from the filler neck and then spray through it into the tank the remaining composition from the channels of the spray gun.

 In the process of mixing the composition with air, there is a danger of ignition in the tank of the mixture with the air of volatile solvents contained in the composition. In case of accidental contact with a gas jet leaving the tank on an open flame or spark, it will ignite, followed by ignition of the vapor under the tank cover. The filter screen located in the upper part of the tank cannot prevent the penetration of the flame inside, under the cover.

 The task of the invention is to eliminate these disadvantages and thereby increase productivity, safety and quality of work, improve the service conditions of the device.

 This is achieved by the fact that in the device for applying anticorrosive mastic, containing a heated reservoir for the coolant, a mastic tank installed in it, in communication with a slot filter, including a filter cup, which is connected by a heated mastic supply hose to a spray gun having a communication with the supply source a heated air hose and a unit for supplying compressed air to a slotted filter for purging, including a locking needle, a slotted filter is placed in a coolant tank I’m under the mastic tank, the unit for supplying compressed air to the slotted filter for purging is made in the form of a nozzle located inside the filter cup with radial holes facing up and a nozzle with a movable nozzle mounted on the spray gun, in the mixing channel of which it is rigidly fixed by means of a pin a needle made with plumage from a plate, equal in width to the diameter of the mixing channel of the nozzle, and with a tip interacting with the hole of the movable nozzle, and the discharge of compressed air from the tank for m sticks made in the form mounted on the exhaust pipe of a tank having a truncated cone shape, on the basis of which is fixed a larger fine-meshed net of metal with high thermal conductivity, and on the surface of the filter glass, having longitudinal grooves, formed a threaded groove in which is laid round section wire.

 By placing a slotted filter in the coolant reservoir, the mastic is accelerated to a working viscosity and filtered at a lower ambient temperature, which improves the productivity and quality of mastic application.

 The upward direction of the radial holes of the nozzle installed inside the filter cup creates conditions for the accumulation of debris contained in the mastic in the bottom of the slot filter while blowing the filter cup with compressed air.

 Due to the placement of a slit filter in the lower part of the coolant tank, under the mastic tank, the conditions for servicing the filter are improved when sediment of debris is removed from it.

 The execution of a threaded groove for a round wire on the filter cup simplifies the design of the slit filter, it becomes possible to adjust the slit gap by replacing one wire with another, different in diameter.

 By equipping the spray gun with a nozzle having a rigidly fixed locking needle in the mixing channel and a movable nozzle, mastic is applied to hard-to-reach surfaces. The service conditions of the device are improved as a result of the closed purge of the spray gun, mastic feed hose, slit filter, and also when the mastic is mixed in the tank, as this excludes any visible contact between the operator and the mastic.

 By performing plumage in the form of a plate on a locking needle in width equal to the diameter of the mixing channel, the nozzle design is simplified, since the needle self-aligns along the axis of the opening of the movable nozzle and is attached to the nozzle by means of a single pin.

 The use of a fine-mesh mesh of metal with high thermal conductivity, for example, copper, in the exhaust pipe provides fire safety for the process of purging a slotted filter and mixing the mastic in the tank with compressed air.

 Figure 1 shows a diagram of a device for applying anti-corrosion mastic; in FIG. 2 - slot filter of the device, section; figure 3 - remote element 1, the exhaust pipe, section; figure 4 - remote element II, the nozzle in the position of applying the mastic, a partial section; 5 is a view A in FIG. 4, the nozzle in the purge position of the filter, cut.

 The device contains a tank 1 for mastic with an intake pipe 2 and a valve 3, a spray gun 4 with a hose 5 for feeding mastic and a hose 6 for supplying compressed air. Tank 1 is placed in the reservoir 7 for the coolant. An electric heating element 8 and a temperature sensor 9 are installed in the tank 7.

 The device has a slotted filter 10, consisting of a housing 11, a filter cup 12 with a flange and an outlet pipe 13 with a nut 14. Through the cylindrical wall of the cup 12, there are through longitudinal grooves 15, a threaded groove 16 is cut into which a round wire 17 with a gap of 18 is laid between turns. At the outlet pipe 13, rigidly fixed in the housing 11, there are made radial holes 19 directed upwards.

 The housing 11 with the nozzle 13 is placed in the reservoir 7 for the coolant, above the heating element 8. The housing 11 is connected to the valve 3, and the outlet nozzle 13 is connected to the mastic feed hose 5 to the spray gun 4.

 The hose 6 is in communication with a source of compressed air (not shown) through the valve 20 and duct 21. The upper part of the tank 1 is connected to the duct 21 through the on-off valve 22 on the cover 23 of the tank 1. On the valve 22 an exhaust pipe 24 is installed, made in the form of a truncated cone. On the larger base of the cone, remote from the crane 22, a fine-mesh mesh 25 is made of metal with high thermal conductivity, for example, copper.

 A node for supplying compressed air to the slotted purge filter 10 is made on the spray gun 4, including a nozzle 26, at the end of which a movable nozzle 27 with an opening 28 is installed. Inside the nozzle 26, coaxially with the opening 28 of the nozzle 27, a shut-off pin is fixed using a pin 29 a needle 30 made with a tip 31 and an empennage 32 in the form of a plate, equal in width to the diameter of the mixing channel 33 of the nozzle 26. The mixing channel 33 of the nozzle 26 through the channels of the spray gun 4, hose 5 and nozzle 13 is in communication with the holes 19 of the nozzle 13.

 The device has a mastic heating system in the hose 5, including an electric heating coil 34 in the mastic supply hose 5, the end of which from the side of the spray gun 4 is connected to the electric heating spiral 35 in the air supply hose 6, while the second ends of the electric heating spirals 34 and 35 through a step-down transformer 36 are connected to a source of electricity.

 Mastic feed hose 5 is connected to the outlet pipe through an electrical insulator 37.

 The air supply hose 6 is also isolated from the faucet 20. As a material for electric coils placed in the hoses 5 and 6, a metal or alloy with a high temperature coefficient of resistance can be used.

 The device operates as follows.

 The tank 1 is loaded with a viscous anticorrosive mastic, and the tank 7 is filled with a coolant, for example, oil.

 When you turn on the electric heating element 8, the coolant in the tank 7 is heated. Temperature control is carried out using sensor 9.

 In the process of heating the coolant in the tank 7, the mastic is heated in the tank 1 and in the slit filter 10.

 When the step-down transformer 36 is turned on, the spiral 35 in the hose 6 and the spiral 34 in the hose 5 are heated, from which the mastic located there is heated. With increasing temperature of the spirals 34 and 35, their resistance increases, and the current in the circuit of the spiral 34 and spiral 35 decreases. This automatically reduces the power of pre-heating the mastic in the hose 5.

 Part of the mastic located in the slit filter 10 is heated faster than the bulk in the tank 1.

 When the mastic reaches the viscosity necessary for high-quality spraying, open the valve 22 and supply compressed air to the tank 1.

 To dispense the mastic, the valve 3 is opened. The mastic heated in the tank 1 under air pressure from the tank 1 through the pipe 2 enters the housing 11 of the slit filter 10. There it is additionally heated and liquefied, passes through the slit gaps 18 of the filter bowl 12 and is cleaned of debris. The cleaned mastic through the holes 19 enters the pipe 13 and through the hose 5 to the spray gun 4.

 When compressed air is supplied through the faucet 20 through a hose 6 to the spray gun 4, the mastic is sprayed from the nozzle 26. The application rate of the mastic is regulated using the nozzle 27 and the needle 30.

 To configure the spray gun 4 for maximum application performance, for example, when mastic is processing large-sized articles of a flat shape, the maximum clearance is set between the tip 31 of the needle 30 and the nozzle opening 28. When the spray gun 4 is turned on, the compressed air in the nozzle 26 creates a minimum backpressure for the mastic supply to spray. At the same time, the consumption of mastic and compressed air spraying it is maximum, which ensures maximum productivity of applying an anti-corrosion coating.

 To quickly reduce application performance, for example, when mastic is processing small shaped articles, the nozzle 27 is moved along the nozzle 26 to the needle 30, reducing the gap between the tip 31 of the needle 30 and the hole 28 of the nozzle 27.

 Due to the reduction in the bore of the opening 28 of the nozzle 27, the air flow from the nozzle 27 decreases, and its pressure in the nozzle 26 increases. As a result of the increased backpressure, the flow of mastic for spraying is reduced, and the performance of the coating is reduced.

 To purge the slit filter 10 and mix the mastic in the tank 1, rotate the nozzle 27 of the nozzle 26 until its opening 28 is completely blocked by the tip 31 of the needle 30. The on-off valve 22 is moved to the position in which the cavity of the tank 1 communicates with the atmosphere.

 Having turned on the spray gun 4, compressed air is fed into the mixing channel 33 of the nozzle 26. Since the hole 28 of the nozzle 27 is blocked by the needle 30 in the nozzle 26 and the channel for the passage of the mastic is open in the spray gun 4, the compressed air displaces the mastic from the gun -spray 4, hose 5, slotted filter 10 and intake pipe 2 back into the tank 1.

 Compressed air flowing from the radial holes 19 of the outlet pipe 13, discards weed inclusions to the wall of the housing 11, through which they fall into the bottom of the slotted filter 10 and accumulate there.

 From the housing 11, the air rises and through the intake pipe 2 enters the tank 1 and mixes the mastic.

 The air entering the tank 1 is mixed with heated vapors of the solvent contained in the mastic, and is discharged into the atmosphere through the valve 22 and exhaust pipe 24. Passing through the mesh 25 of the exhaust pipe 24, the gas stream is dispersed.

 In case of accidental ignition of a gas stream, the heat of the flame is removed by a fine mesh network 25 due to the high thermal conductivity of its metal. Therefore, the flame does not penetrate through the mesh 25 into the exhaust pipe 24 and the tank 1.

 This ensures fire safety of the purge process of the slit filter 10 and mixing the mastic in the tank 1.

 The use of a heated slotted filter 10 increases the technological reliability and productivity of applying viscous mastic at a low temperature, and reduces the time and energy required to put the device into operation.

 The proposed simple design nozzle 26 with a locking needle 30 and a movable nozzle 27 is suitable for use on serial spray guns. At the same time, the quality of anticorrosion treatment of hard-to-reach surfaces of machines will increase, the mastic losses will be reduced due to operational changes in the application performance, the service conditions of the device will be improved when the slotted filter 10 is closed while the mastic is mixed in the tank 1.

Claims (3)

 1. A device for applying anticorrosive mastic, containing a heated reservoir for a coolant, a mastic tank installed in it, in communication with a slotted filter including a filter cup, which is connected by a heated mastic supply hose to a spray gun having a heated air connected to a compressed air supply a hose and a unit for supplying compressed air to the slotted filter for purging, including a locking needle, characterized in that the slotted filter is placed in the coolant reservoir one tank for mastic, the unit for supplying compressed air to the slotted filter for purging is made in the form of a nozzle located inside the filter cup with radial holes pointing upwards and mounted on a spray gun nozzle with a movable nozzle, in the mixing channel of which the needle is rigidly fixed with a pin through a pin made with plumage from a plate, equal in width to the diameter of the mixing channel of the nozzle, and a tip interacting with the opening of the movable nozzle.  2. The device according to claim 1, characterized in that the discharge of compressed air from the mastic tank is made in the form of an exhaust pipe mounted on the tank having the shape of a truncated cone, on a larger base of which a fine-mesh mesh of metal with high thermal conductivity is fixed.  3. The device according to claim 1, characterized in that on the surface of the filter cup having longitudinal grooves, a threaded groove is made in which a circular wire is laid.

Images