Positive pressure type ultra-high molecular weight polyethylene fiber drafting hot box

Abstract

The invention relates to a positive pressure type ultra-high molecular weight polyethylene fiber drafting hot box which comprises a pressurizing box, two V-shaped pipes bent downwards and a heating unit, the two V-shaped pipes are symmetrically connected to the upper portions of the two sides of the pressurizing box, and a drafting channel which enters from the V-shaped pipe on one side, passes through the pressurizing box and then exits from the V-shaped pipe on the other side is formed; one side of the V-shaped pipe close to the pressurizing box is a descending section, and one side far away from the pressurizing box is an ascending section; the heating unit is arranged in the pressurizing box; a plurality of free rollers for conveying ultra-high molecular weight polyethylene fibers are arranged in the V-shaped pipe and the pressurizing box; water is injected into the pressurizing box and the lower portions of the V-shaped pipes, the heating unit heats the water in the pressurizing box to enable water vapor to be evaporated, so that the water pressure in the pressurizing box is increased, the water in the V-shaped pipes on the two sides is pressed to move to the high position towards the ascending section of the pipeline, the high-pressure state in the pressurizing box is maintained, and therefore it is ensured that the water temperature in the pressurizing box meets the hot drafting operation requirement.

Description

Technical Field

[0001] The invention relates to the technical field of ultra-high molecular weight polyethylene fiber spinning hot drawing equipment, in particular to an ultra-high molecular weight polyethylene fiber spinning and drawing hot box. Background Art

[0002] The drafting hot box is a key equipment for achieving high-multiple drafting and super-multiple stretching of ultra-high molecular weight polyethylene fibers. The existing drafting hot box is generally a hot air box, which has a working channel with a tow inlet and an air inlet at one end and a tow outlet and an air outlet at the other end. The air duct with an air inlet and an air outlet is arranged at both ends below the working channel. A fan, a pressure equalizer and a heater are arranged in the air duct. The air inlet and the air outlet of the air duct are respectively connected to the air outlet and the air inlet of the working channel. The fiber tow passes through the working channel and is circulated and heated by the hot air provided by the heater and the fan in the air duct. The design of the openings at both ends of the hot box causes a large amount of heat energy to overflow, which not only wastes energy but also worsens the working environment of the factory. The air flow in the working channel is easily disturbed, causing the fiber stretching point to change back and forth, affecting the fiber fineness and strength stability. The thermal conductivity of air is low, and the temperature of the working channel needs to be much higher than the softening temperature, which causes the surface of the tow to melt and bond, affecting the fiber opening and strength. Due to the high temperature of the working channel, temporary parking time of more than 5 minutes will cause stiff and broken fibers, resulting in waste and increased production costs. In addition, air conducts heat slowly, and the traditional heat box is 4-8 meters long. In order to increase the fiber passing speed and increase production capacity, a longer drafting heat box is required, which will lead to more uneven air volume in the working channel of the heat box.

[0003] The Chinese patent with application number CN200710133411.8 is based on the existing drafting hot box, and an upper air duct with the same configuration as the lower air duct is provided above the working channel. Specifically, a working channel with a fiber bundle inlet and a lower air inlet at one end and a fiber bundle outlet and a lower air outlet at the other end is provided in the box body, and a lower air duct with an air inlet and an air outlet at both ends is provided below the working channel, and the air inlet and air outlet of the lower air duct are respectively connected with the lower air outlet and lower air inlet of the working channel, and a fan, a pressure equalizer and a heater are provided in the lower air duct; wind direction adjustment plates are provided at the upper and lower air inlets of the working channel to adjust the wind direction of the hot air entering the working channel and the refraction angle of the hot air in the working channel, so as to make the heating of the fiber bundle more uniform. This patent adopts two layers of upper and lower air ducts, each with an independent heating system and installs guide plates. Although it has a certain regulating effect on the wind direction of the inlet and outlet of the filament bundle, it cannot solve the problems of air volume and temperature difference on the left and right sides of the same hot box outlet, nor can it solve the problem of uneven heating of the resistance heater itself.

[0004] The Chinese patent with application number CN201720478298.6 also adopts electric heating. Multiple air ducts are arranged longitudinally at the bottom or top of the tow running chamber. The air outlet of each air duct is arranged at the inlet end and connected to the tow running chamber. A fan is installed on the right end of each air duct. A heater, a temperature controller and an air equalizer are arranged in sequence from right to left in each air duct. A wind direction adjuster is installed on the air outlet of the air duct. This patent attempts to arrange multiple channels longitudinally, each channel independently supplies air and adjusts the air volume of multiple channels. Like patent CN200710133411.8, it only adjusts the inlet and outlet air volume and wind direction, and can only adjust the inlet and outlet wind direction and air volume, and cannot fundamentally solve the uneven wind direction and air volume on both sides of the hot box inlet.

[0005] At room temperature (20°C), the thermal conductivity of air is 0.0267. Air is not only unsuitable for use as a thermal conductive material, but is often used as a thermal insulation material. Therefore, a liquid medium with high thermal conductivity, which can be heated to 120°C and does not pollute the fiber, is needed to replace air for thermal conduction.

[0006] Water is a liquid medium with high thermal conductivity (the thermal conductivity reaches 0.585 at room temperature, which is 22 times that of air under the same conditions), clean and cheap, but it has a low boiling point at normal pressure and cannot meet the requirements of fiber drawing. Summary of the invention

[0007] In order to overcome the shortcomings of the prior art, the present invention provides a positive pressure polyethylene fiber drawing hot box with reasonable structure and uniform heating. The technical solution adopted by the present invention to solve its technical problems is: A positive pressure ultra-high molecular weight polyethylene fiber drawing hot box, comprising a booster box, two downwardly bent V-shaped tubes and a heating unit, wherein the two V-shaped tubes are symmetrically connected to the upper parts of both sides of the booster box to form a drawing channel that enters from the V-shaped tube on one side, passes through the booster box, and then exits through the V-shaped tube on the other side; the side of the V-shaped tube near the booster box is a descending section, and the side far from the booster box is an ascending section; the heating unit is arranged in the booster box; a plurality of free rollers for ultra-high molecular weight polyethylene fiber transmission are built in the V-shaped tube and the booster box; water is injected into the lower part of the booster box and the V-shaped tube, the heating unit heats the water in the booster box to evaporate the water vapor, thereby increasing the water pressure in the booster box, and the water in the V-shaped tubes on both sides is pressurized to move to a high position toward the ascending section of the pipeline to maintain the high pressure state in the booster box, thereby ensuring that the water temperature in the booster box meets the needs of hot drawing operation.

[0008] The positive pressure ultra-high molecular weight polyethylene fiber drawing heat box is further designed in that the heating unit is an electric heating wire.

[0009] The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box is further designed in that the heating unit is a steam coil, one end of the steam coil extends to the outside of the booster box and is connected to a high-temperature steam source.

[0010] The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box is further designed in that a water supply pipeline is provided near the opening of the rising section of the V-shaped tube located on one side of the booster box, which is used to supply water to the V-shaped tube; the booster box and the two V-shaped tubes are connected to each other, and a water pump is provided in the connecting pipeline to adjust the water supplied to the corresponding V-shaped tube from the outside to the booster box and the V-shaped tube on the other side.

[0011] The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box is further designed in that the other end of the steam coil extends to the outside of the booster box and is connected to a condensing water tank; the condensing water tank is connected to the upper part of the rising section of the V-shaped tube on one side through a water supply pipeline, and a water supply pump is arranged in the water supply pipeline, and the V-shaped tube on this side is a water supply V-shaped tube, and the water supply pump replenishes the water in the condensing water tank into the water supply V-shaped tube; the bending parts of the two V-shaped tubes at the bottom are connected through a regulating water pipe; a regulating branch pipe connected to the booster box is connected to the middle part of the regulating water pipe; a two-way water pump is arranged on one side of the regulating water pipe near the water supply V-shaped tube, and the two-way water pump is used to regulate the water in the water supply V-shaped tube to the booster box or the V-shaped tube on the other side.

[0012] The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box is further designed in that the booster box, V-shaped tube and free roller are made of stainless steel or coated with anti-rust coating.

[0013] The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box is further designed in that the booster box and the outer side of the V-shaped tube are covered with an insulation layer.

[0014] The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box is further designed in that the booster box and the two V-shaped tubes are respectively provided with maintenance ports corresponding to the free rollers, and the maintenance ports are provided with sealing doors.

[0015] The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box is further designed in that the booster box is provided with a pressure sensor and a pressure relief valve, and the signal of the pressure sensor is linked with the pressure relief valve to control the pressure in the booster box.

[0016] The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box is further designed in that the booster box is provided with a liquid level sensor, and the liquid level sensor signal is linked with the two-way pump and the pneumatic valve behind the pump to control the liquid level in the booster box.

[0017] The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box is further designed in that the height from the maintenance port of the V-shaped tube to the top is not less than 10 meters.

[0018] The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box is further designed in that the height difference between the V-shaped tube maintenance port and the channel liquid level is greater than or equal to 5 meters at normal pressure.

[0019] The beneficial effects of the present invention are: Water with a high specific heat capacity is used as the heating medium, and the gravity of the water itself is used to provide pressure for the booster box so that the water temperature in the booster box can meet the needs of hot stretching operation, the heating temperature is uniform, and the fiber can enter and exit the booster box along the waterway. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0022] As shown in the figure, a positive pressure ultra-high molecular weight polyethylene fiber drawing hot box comprises a booster box 1, two downwardly bent V-shaped tubes 2 and a heating unit 3, wherein the two V-shaped tubes are symmetrically connected to the upper parts of both sides of the booster box to form a drawing channel that enters from the V-shaped tube on one side, passes through the booster box, and then exits through the V-shaped tube on the other side; the side of the V-shaped tube near the booster box is a descending section, and the side far from the booster box is an ascending section; the heating unit is arranged in the booster box; the V-shaped tube 2 and the booster box are equipped with a plurality of free rollers 4 for ultra-high molecular weight polyethylene fiber transmission; the booster box and the lower part of the V-shaped tube are filled with water, the heating unit 3 heats the water in the booster box to evaporate the water vapor, thereby increasing the water pressure in the booster box, and the water in the V-shaped tubes on both sides is pressurized to move to a high position toward the ascending section of the pipeline to maintain the high pressure state in the booster box, thereby ensuring that the water temperature in the booster box meets the needs of the hot drawing operation.

[0023] The tow is passed from the left V-shaped pipe inlet along the free rollers to the right V-shaped pipe outlet. A water injection hole is provided above the booster box. Water is added to the booster box until the water level overflows the free roller 4 at the bottom. All valves are checked and closed. Water is added to the V-shaped pipes 2 on both sides to a height of 5 meters above the bottom.

[0024] The heating unit 3 works, and the heat box starts to heat up. As the temperature rises, the steam gradually increases the pressure in the box, and the air pressure pushes the water in the V-shaped tube to the outer outlet. When the water level approaches the outlet of the V-shaped tube, the pressure in the box will reach 0.2Mpa and the temperature will reach 120℃. At this time, the temperature sensor 5 installed on the booster box sends a signal to reduce the heat supply of the heating unit 3. The pressure sensor 6 sends a signal to the pressure reducing valve 7 linked to it to open the pressure reducing valve. The temperature and pressure of the hot box gradually stabilize and reach a balance, and start the normal drafting.

[0025] The heating unit can be directly selected from electric heating wires. Of course, the steam coil described below can also be selected. The only difference between the two is that when the steam coil is used, steam condensate can be used as a pure water supply source. In this case, the heating unit is a steam coil 3, one end of which extends to the outside of the booster box and is connected to a high-temperature steam source.

[0026] The other end of the steam coil extends to the outside of the booster tank and is connected to a condensate water tank 8; the condensate water tank is connected to the upper part of the rising section of the V-shaped pipe on one side through a water supply pipeline 9, and a water supply pump 10 is provided in the water supply pipeline. The V-shaped pipe on this side is a water supply V-shaped pipe, and the water supply pump replenishes the water in the condensate water tank into the water supply V-shaped pipe; the bending parts of the two V-shaped pipes at the bottom are connected through a regulating water pipe 11; a regulating branch pipe 12 connected to the booster tank is connected to the middle part of the regulating water pipe; a two-way water pump 13 is provided on one side of the regulating water pipe near the water supply V-shaped pipe, and the two-way water pump is used to regulate the water in the water supply V-shaped pipe to the booster tank 1 or the V-shaped pipe 2 on the other side.

[0027] The condensed water at the condensed water outlet 2 passes through the 4 steam trap and goes to the hot water storage tank. Since the fiber tow will take away the water in the box and the V-shaped pipe when traveling at high speed, the water level in the box will continue to decrease. When the liquid level reaches the set water replenishment level, the liquid level sensor 14 sends a water replenishment signal, closes and opens the corresponding valve, so that the water replenishment V-shaped pipe is connected to the booster tank, and the two-way water pump pumps the water in the water replenishment V-shaped pipe into the booster tank through the regulating branch pipe. Similarly, when the water in the V-shaped pipe on the other side is insufficient, the water in the water replenishment V-shaped pipe can also be pumped to the V-shaped pipe on the other side.

[0028] The booster box, V-shaped pipe and free roller are made of stainless steel or coated with anti-rust coating.

[0029] The outside of the booster box and the V-shaped tube are covered with an insulation layer. The booster box and the two V-shaped tubes are each provided with a maintenance port corresponding to the free roller, and the maintenance port is provided with a sealing door 15. When the free roller in the booster box fails, the pressure therein is emptied, and the maintenance personnel enter the box from the corresponding maintenance port to carry out repairs; when the free roller in the V-shaped tube fails, the water in the V-shaped tube on that side is pumped into the V-shaped tube on the other side, and after the water is emptied, the maintenance port is opened for repairs. The height from the maintenance port of the V-shaped tube to the top is not less than 10 meters. The height difference from the maintenance port of the V-shaped tube to the liquid level of the channel is greater than or equal to 5 meters at normal pressure.

Claims

1. A positive pressure ultra-high molecular weight polyethylene fiber drawing hot box, It is characterized in that It includes a booster box, two downwardly bent V-shaped tubes and a heating unit, the two V-shaped tubes are symmetrically connected to the upper parts of both sides of the booster box to form a stretching channel that enters from the V-shaped tube on one side, passes through the booster box, and then exits through the V-shaped tube on the other side; the side of the V-shaped tube near the booster box is a descending section, and the side far from the booster box is an ascending section; the heating unit is arranged in the booster box; the V-shaped tube and the booster box are equipped with a number of free rollers for transmitting ultra-high molecular weight polyethylene fibers; the booster box and the lower part of the V-shaped tube are filled with water, the heating unit heats the water in the booster box to evaporate the water vapor, thereby increasing the water pressure in the booster box, and the water in the V-shaped tubes on both sides is pressurized to move to a high position toward the ascending section of the pipeline to maintain the high pressure state in the booster box, thereby ensuring that the water temperature in the booster box meets the needs of the hot stretching operation.

2. A positive pressure ultra-high molecular weight polyethylene fiber drawing hot box according to claim 1, It is characterized in that The heating unit is an electric heating wire.

3. The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box according to claim 1, It is characterized in that The heating unit is a steam coil, one end of which extends to the outside of the booster box and is connected to a high-temperature steam source.

4. The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box according to any one of claims 1 to 3, It is characterized in that A water supply pipeline is arranged near the opening of the ascending section of the V-shaped tube located on one side of the booster tank, which is used to supply water to the V-shaped tube; the booster tank and the two V-shaped tubes are connected to each other, and a water pump is arranged in the connecting pipeline to adjust the water supplied from the outside to the corresponding V-shaped tube to the booster tank and the V-shaped tube on the other side.

5. The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box according to claim 3, It is characterized in that The other end of the steam coil extends to the outside of the booster tank and is connected to a condensate water tank; the condensate water tank is connected to the upper part of the rising section of the V-shaped tube on one side through a water supply pipeline, a water supply pump is provided in the water supply pipeline, the V-shaped tube on this side is a water supply V-shaped tube, and the water supply pump replenishes the water in the condensate water tank into the water supply V-shaped tube; the two V-shaped tubes are connected at the bottom of the bending parts through a regulating water pipe; a regulating branch pipe connected to the booster tank is connected to the middle part of the regulating water pipe; a two-way water pump is provided on one side of the regulating water pipe near the water supply V-shaped tube, and the two-way water pump is used to regulate the water in the water supply V-shaped tube to the booster tank or the V-shaped tube on the other side.

6. The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box according to claim 1, It is characterized in that The booster box, V-shaped pipe and free roller are made of stainless steel or coated with anti-rust coating.

7. The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box according to claim 1, It is characterized in that The outsides of the booster box and the V-shaped tube are covered with a thermal insulation layer.

8. The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box according to claim 1, It is characterized in that The boost box and the two V-shaped tubes are respectively provided with maintenance openings corresponding to the free rollers, and the maintenance openings are provided with sealing doors.

9. The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box according to claim 1, It is characterized in that The boost box is provided with a pressure sensor and a pressure relief valve, and the signal of the pressure sensor is linked with the pressure relief valve to control the pressure in the boost box.

10. The positive pressure ultra-high molecular weight polyethylene fiber drawing hot box according to claim 5, It is characterized in that The booster box is provided with a liquid level sensor, and the liquid level sensor signal is linked with the two-way pump and the pneumatic valve after the pump to control the liquid level in the booster box.

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