Polyurethane spraying device for nodular cast iron prefabricated thermal insulation pipe

Abstract

The utility model provides a nodular cast iron prefabricated thermal insulation pipe polyurethane spraying device in the field of thermal insulation pipe processing, which comprises a spraying system, a feeding system and a control system, the spraying system comprises a spray gun, a foaming machine and a track trolley, and the left side wall of a spraying box is provided with a spraying opening for the spray gun to enter and exit; the feeding system comprises an isocyanate black material storage tank and a combined polyether white material storage tank, a main feeding pipeline and a standby feeding pipeline which are arranged in parallel are arranged between the two storage tanks and the foaming machine, and a feeding pump, a flow transmitter and a control valve are arranged on each feeding pipeline in series. The foaming machine is telescopically connected with the two conveying pipelines through rubber hoses; the control system comprises an operation table arranged on the outer side of the spraying box. According to the utility model, modification is mainly carried out on the aspects of feeding system and nozzle adjustment, the situation that the production efficiency is influenced by shutdown of the whole system due to failure of one single-line feeding device is avoided, the position of the spray gun can be conveniently adjusted, and the spraying device can adapt to spraying processing of thermal insulation pipes with different pipe diameters.

Description

Technical Field

[0001] The utility model belongs to the technical field of processing of thermal insulation pipes, and particularly relates to a polyurethane spraying device for ductile iron prefabricated thermal insulation pipes. Background Art

[0002] Thermal insulation pipes, also known as heat pipes, mainly consist of a working steel pipe wrapped with a thermal insulation layer and an outer protective layer on the outside. Polyurethane sprayed polyethylene wound thermal insulation pipes are a relatively mainstream type of heat pipe at present. They are prefabricated thermal insulation pipes with a polyurethane thermal insulation layer sprayed on the outside of the working steel pipe and then a polyethylene outer protective layer wound around. Most of their working steel pipes still use ordinary seamless steel pipes, and their performance in terms of corrosion resistance, mechanical strength, etc. is still insufficient, seriously affecting the service life of the pipes. To solve this problem of thermal insulation pipes, in recent years, the production and application of ductile iron prefabricated thermal insulation pipes have been increasing. Because ductile iron material combines the characteristics of iron and the performance of steel, it has excellent characteristics such as good corrosion resistance, pressure resistance, and tensile strength. The following problems mainly exist in the polyurethane thermal insulation layer spraying devices used in the processing of existing ductile iron prefabricated thermal insulation pipes: on the one hand, the adaptability to the pipe diameter is limited, the position of the spray gun is not convenient to adjust, and too thick or too thin pipe diameters will cause the spraying effect of the polyurethane thermal insulation layer to be not ideal; on the other hand, the operation reliability of the thermal insulation layer spraying feeding system is lacking. Any equipment failure in the feeding device will cause the entire system to collapse, and the spraying work of the pipe thermal insulation layer can only stop, seriously affecting the production efficiency of thermal insulation pipes. Therefore, it is urgent to transform and upgrade the existing ductile iron thermal insulation pipe spraying devices. Summary of the Utility Model

[0003] In view of the above situation, the utility model provides a polyurethane spraying device for ductile iron prefabricated thermal insulation pipes, and has carried out targeted technical transformations in the feeding system and spray head adjustment of the spraying device, which well solves the existing technical problems mentioned in the above background art.

[0004] To achieve the above purposes, the utility model adopts the following technical solutions:

[0005] A polyurethane spraying device for ductile iron prefabricated thermal insulation pipes includes a feeding transmission line for spirally conveying the pipes to be sprayed, an electromagnetic induction heater for heating the pipes, a spraying box for spraying polyurethane thermal insulation layer on the pipe surface, and a discharging transmission line for spirally conveying the pipes after spraying, which are linearly arranged in sequence from front to back according to the pipe traveling direction. The feeding and discharging transmission lines can drive the pipes to be conveyed in a spiral shape (rotating circumferentially and advancing axially). The ductile iron pipes pass through the middle of the coil of the electromagnetic induction heater while completing electromagnetic induction heating, which is convenient for the hot melt adsorption of the subsequent polyurethane spraying material.

[0006] The front and rear end faces of the spraying box are respectively provided with a feed inlet and a discharge outlet for the pipeline to pass through; a spraying mechanism is arranged outside the left side of the spraying box, and the spraying mechanism includes a spraying system, a feeding system and a control system. The spraying system includes a spray gun, a foaming machine and a rail trolley. The foaming machine is installed above the movable rail trolley, and the spray gun is installed at the spraying end of the foaming machine close to the pipeline. A spraying port for the spray gun to stretch in and out is cooperatively arranged on the left side wall of the spraying box.

[0007] The feeding system includes a black material storage tank for containing isocyanate (commonly known as black material), a white material storage tank for containing polyether polyol (commonly known as white material), a black material conveying pipeline connected between the black material storage tank and the foaming machine, and a white material conveying pipeline connected between the white material storage tank and the foaming machine; isocyanate and polyether polyol react in the foaming machine to generate foamy polyurethane, which is then sprayed onto the pipeline surface through the spray gun; the equipment composition and pipeline settings of the black material conveying pipeline and the white material conveying pipeline are exactly the same. Each of the two conveying pipelines includes two feeding pipelines arranged in parallel, one main and one standby. A feeding pump, a flow transmitter and a control valve are arranged in series on each feeding pipeline. And the foaming machine is telescopically connected with the two conveying pipelines through rubber hoses, and cannot interfere with the movement of the spraying system.

[0008] The control system includes an operating platform arranged outside the spraying box. A control circuit for controlling the entire spraying device is arranged in the operating platform. The feeding transmission line, the discharging transmission line, the electromagnetic induction heater, as well as the spraying system and the feeding system are all electrically connected to the operating platform.

[0009] Further, the rail trolley includes a horizontal chassis and a linear module. The linear module is vertically fixed above the horizontal chassis. The foaming machine and the spray gun are horizontally connected to the right side of the lifting slide of the linear module. An elevating motor is arranged on the top of the linear module; a linear guide rail is cooperatively laid on the ground below the rail trolley. The four corners of the horizontal chassis are rollably arranged above the linear guide rail through rollers, and a traveling motor connected to each of the rollers is arranged on the horizontal chassis.

[0010] Further, an elastic rubber curtain is cooperatively arranged in a ring shape on the inner sides of the feed inlet and the spraying port of the spraying box. When the pipeline enters the spraying box through the feed inlet, the rubber curtain of the feed inlet will always elastically cling to the pipeline surface to block the gap between the pipeline and the feed inlet as much as possible. Similarly, the rubber curtain of the spraying port is also to minimize the gap between the spray gun and the spraying port to reduce the escape of the polyurethane spraying material.

[0011] Further, a pressure transmitter and a temperature transmitter are respectively arranged on each feeding pipeline to detect the conveying pressure and the material temperature of the feeding pipeline. The reaction of isocyanate and polyether polyol to generate polyurethane foam has certain requirements for temperature and pressure conditions.

[0012] Furthermore, on the feed pipelines between the two conveying pipelines and the foaming machine, return pipelines are bifurcated and connected evenly. The two return pipelines are respectively connected to the black material storage tank and the white material storage tank through return valves.

[0013] The present utility model further includes other components that enable its normal use, which are all conventional means in the art. In addition, for devices or components not defined in the present utility model, such as the inlet and outlet transmission lines of the conveying pipeline, the electromagnetic induction heater, the isocyanate material and its storage tank and feed pipeline equipment, the polyether polyol material and its storage tank and feed pipeline equipment, and the polyurethane spray gun, etc., the existing technologies in the art are adopted.

[0014] The beneficial effects of the present utility model are as follows:

[0015] A polyurethane spraying device for ductile iron prefabricated insulated pipes provided by the present utility model sets the feed pipelines of isocyanate (black material) and polyether polyol (white material) both as one main and one standby, which avoids the problem that the entire system will stop when a single device fails in the existing single-line feeding system, thus affecting the spraying efficiency of the pipeline insulation layer, and is conducive to improving the production efficiency of the insulated pipe production line; in addition, by installing a movable track trolley facility for the polyurethane spray gun, the up, down, left and right positions of the spray gun can be adjusted, which avoids the problem that the distance between the spray gun and the pipe surface is too close or too far when processing pipes with different diameters, thus affecting the spraying effect of the pipeline insulation layer, is conducive to ensuring the spraying quality of the insulated pipe, and at the same time improves the compatibility and adaptability of the polyurethane insulation layer spraying device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a top view schematic diagram of the polyurethane spraying device for ductile iron prefabricated insulated pipes in the embodiment.

[0017] Figure 2 It is Figure 1 a schematic diagram of the equipment connection of the feeding system of the spraying mechanism in

[0018] Figure 3 It is Figure 1 a schematic diagram of the track trolley structure of the spraying system in

[0019] Figure 4 It is Figure 1 a three-dimensional structure schematic diagram of the spraying box in DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] Next, the technical solutions of the present utility model will be clearly and completely described in combination with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present utility model, rather than all embodiments.

[0021] It should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "inner", "outer", etc., indicating orientation or positional relationship are all based on the figures shown, and are only for convenience of description.

[0022] Embodiment

[0023] As Figure 1 Shown in the figure, a polyurethane spraying device for ductile iron prefabricated insulating pipes includes a feeding transmission line 1 for helically transporting the pipes to be sprayed, arranged linearly in sequence from front to back along the pipe traveling direction, an electromagnetic induction heater 2 for heating the pipes, a spraying box 3 for spraying a polyurethane insulating layer onto the pipe surface, and a discharging transmission line 4 for helically transporting the pipes after spraying.

[0024] The feeding and discharging transmission lines can drive the pipes to rotate circumferentially and travel axially while being transported. The main body of the electromagnetic induction heater is a horizontally arranged electromagnetic induction coil, and the ductile iron pipe passes through the middle of the coil while completing electromagnetic induction heating. The pipe transmission line and the electromagnetic induction coil both belong to the prior art in this field, and their specific settings will not be elaborated here.

[0025] Round hole-shaped feeding ports 5 and discharging ports 6 for the pipes to pass through are respectively opened on the front and rear end faces of the spraying box; a spraying mechanism is arranged outside the left side of the spraying box. The spraying mechanism includes a spraying system, a feeding system, and a control system. The spraying system includes a spray gun 7, a foaming machine 8, and an orbital trolley. The foaming machine is installed above the movable orbital trolley, and the spray gun is installed at the spraying end of the foaming machine close to the pipe. A spraying port 9 for the spray gun to stretch in and out is cooperatively opened on the left side wall of the spraying box.

[0026] As Figure 2 Shown in the figure, the feeding system includes a black material storage tank 10 for containing isocyanate and a white material storage tank 11 for containing polyol blend, as well as a black material conveying pipeline connected between the black material storage tank and the foaming machine and a white material conveying pipeline connected between the white material storage tank and the foaming machine. The isocyanate and the polyol blend react in the foaming machine to generate foamy polyurethane, which is then sprayed onto the pipe surface through the spray gun; the equipment composition and pipeline settings of the black material conveying pipeline and the white material conveying pipeline are exactly the same. Each of the two conveying pipelines includes two feeding pipelines arranged in parallel with one main and one standby. A feeding pump 12, a flow transmitter 13, and a control valve 14 are serially arranged on each feeding pipeline; the operator can, according to the actual situation, for example, when the main line equipment fails, operate each control valve according to experience to achieve the switching between the main and standby feeding pipelines, and the foaming machine is telescopically connected to the two conveying pipelines through a rubber hose 15, which will not interfere with the left and right movement of the orbital trolley.

[0027] The control system includes an operating console 16 arranged outside the spraying tank. A control circuit for controlling the entire spraying device is arranged inside the operating console. The feeding transmission line, the discharging transmission line, the electromagnetic induction heater, the spraying system and the feeding system are all electrically connected to the operating console. The operating console and its internal control circuit both adopt existing technologies, and the specific settings are not elaborated here.

[0028] Specifically, as Figure 3 shown, the rail trolley includes a horizontal chassis 17 and a linear module 18. The linear module is vertically fixed above the horizontal chassis. The foaming machine and the spray gun are horizontally connected to the right side of the lifting slide 19 of the linear module. A lifting motor 20 is arranged at the top of the linear module, which can realize the lifting adjustment of the up and down position of the spray gun. A linear guide rail 21 is laid on the ground below the rail trolley in a matching manner. The four corners of the horizontal chassis are arranged above the linear guide rail in a rollable manner through rollers 22. A traveling motor 23 connected to each of the rollers in a transmission manner is arranged on the horizontal chassis, which can realize the telescopic adjustment of the left and right positions of the spray gun to ensure a suitable distance from the spray gun to the surface of the pipeline. The foaming machine, the spray gun, the linear module, the rollers, the linear guide rail, etc. all adopt existing technologies, and the specific settings are not elaborated here.

[0029] Specifically, as Figure 4 shown, a circle of elastic rubber curtains 24 is respectively arranged in a surrounding manner on the inner sides of the feeding port and the spraying port of the spraying tank. When the pipeline is spirally conveyed through the electromagnetic induction heater by the feeding transmission line and then enters the spraying tank through the feeding port, no matter the diameter of the processed pipeline is thick or thin, the rubber curtain at the feeding port can always elastically adhere to the surface of the pipeline well, and try to block the gap between the pipeline and the feeding port to reduce the escape of the polyurethane spraying material. Similarly, the rubber curtain at the spraying port is also to minimize the gap between the spray gun and the spraying port and reduce the escape of the polyurethane spraying material to protect the on-site environment of the workshop.

[0030] Specifically, a pressure transmitter 25 and a temperature transmitter 26 are respectively arranged in a matching manner on each feeding pipeline for detecting the conveying pressure and the material temperature of the feeding pipeline. The pressure transmitter and the temperature transmitter are both electrically connected to the operating console. The conveying pressure of the pipeline material can be adjusted by changing the flow rate of the feeding pump. The black and white material storage tanks are double-layer jacketed tanks, and a heating device is arranged in the interlayer. The material temperature can be adjusted by circulating between the return pipeline and the storage tank. The flow transmitter, the pressure transmitter and the temperature transmitter, as well as the feeding pump, the black and white material storage tanks and the pipeline valves on each of the main and standby double feeding pipelines corresponding to them all adopt existing technologies, and the specific settings are not elaborated here.

[0031] Specifically, on the feed pipelines between the two conveying pipelines and the foaming machine, return pipelines are connected through three-way bifurcations. The two return pipelines are respectively connected to the black material storage tank and the white material storage tank through return valves 27. A feed valve 28 is also provided at the front end of the spray gun. When it is necessary to adjust the temperature of the pipeline material or temporarily suspend the spraying of the spray gun, the interlock switch of the feed valve at the front end of the spray gun and the return valve of the return pipeline can be controlled in cooperation to realize the temporary return circulation of the material. All the above pipeline valves are electric control valves that can be centrally controlled through an operation console. The return pipeline and its return valve, the spray gun and its feed valve, the rubber hose, and the interlock control between the feed valve and the return valve, etc. all adopt existing technologies, and the specific settings are not elaborated here.

[0032] The technical solution of the present utility model is not limited to the limitations of the above specific embodiments. Without departing from the scope and spirit of the described embodiments, many modifications and changes are obvious to those of ordinary skill in the art. Any technical deformation made within the spirit and principle of the present utility model falls within the protection scope of the present utility model.

Claims

1. A polyurethane spraying device for ductile iron prefabricated thermal insulation pipes, comprising a feeding transmission line for helically conveying the pipes to be sprayed, arranged in a straight line from front to back in the pipeline traveling direction, an electromagnetic induction heater for heating the pipes, a spraying box for spraying a polyurethane thermal insulation layer on the pipe surface, and a discharging transmission line for helically conveying the pipes after spraying, characterized in that: At the front and rear end faces of the spraying box, a feed inlet and a discharge outlet for the pipeline to pass through are respectively provided; a spraying mechanism is arranged outside the left side of the spraying box. The spraying mechanism includes a spraying system, a feeding system and a control system. The spraying system includes a spray gun, a foaming machine and a rail trolley. The foaming machine is installed above the movable rail trolley, and the spray gun is installed at the spraying end of the foaming machine close to the pipeline. A spraying port for the spray gun to stretch in and out is cooperatively arranged on the left side wall of the spraying box; the feeding system includes a black material storage tank for containing isocyanate, a white material storage tank for containing polyether polyol, a black material conveying pipeline connected between the black material storage tank and the foaming machine, and a white material conveying pipeline connected between the white material storage tank and the foaming machine. The equipment composition and pipeline arrangement of the black material conveying pipeline and the white material conveying pipeline are exactly the same. Each of the two conveying pipelines includes two feeding pipelines arranged in parallel with one main and one standby. A feeding pump, a flow transmitter and a control valve are serially arranged on each feeding pipeline, and the foaming machine is telescopically connected to the two conveying pipelines through a rubber hose; the control system includes an operating platform arranged outside the spraying box. A control circuit for controlling the whole spraying device is arranged in the operating platform. The feeding transmission line, the discharging transmission line, the electromagnetic induction heater, the spraying system and the feeding system are all electrically connected to the operating platform.

2. The polyurethane spraying device for ductile iron prefabricated thermal insulation pipes according to claim 1, wherein: The rail trolley includes a horizontal chassis and a linear module. The linear module is vertically fixed above the horizontal chassis. The foaming machine and the spray gun are horizontally connected to the right side of the lifting slide of the linear module. A lifting motor is arranged at the top of the linear module.

3. The polyurethane spraying device for ductile iron prefabricated thermal insulation pipes according to claim 2, wherein: A linear guide rail is cooperatively laid on the ground below the rail trolley. The four corners of the horizontal chassis are rotatably arranged above the linear guide rail through rollers, and a traveling motor connected to each of the rollers is arranged on the horizontal chassis.

4. A polyurethane spraying device for ductile iron prefabricated thermal insulation pipes according to claim 1, characterized in that: A circle of elastic rubber curtains is cooperatively arranged around the inner sides of the feed inlet and the spraying port of the spraying box.

5. A polyurethane spraying device for ductile iron prefabricated thermal insulation pipes according to claim 1, characterized in that: A pressure transmitter and a temperature transmitter are respectively arranged on each feeding pipeline for detecting the conveying pressure and the material temperature of the feeding pipeline.

6. A polyurethane spraying device for ductile iron prefabricated thermal insulation pipes according to claim 1, characterized in that: The feeding pipelines between the two conveying pipelines and the foaming machine are respectively branched and connected with a reflux pipeline, and the two reflux pipelines are respectively connected to the black material storage tank and the white material storage tank through reflux valves.

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