阅读说明：本技术 一种聚四氟乙烯鲍尔环制品生产方法 (production method of polytetrafluoroethylene pall ring product ) 是由 姚袁生 仇桂芹 韦存花 柏立楼 张福高 于 2019-09-06 设计创作，主要内容包括：本发明公开了一种聚四氟乙烯鲍尔环制品生产方法,包括以下步骤：(1)原料混合；(2)模压；(3)脱模；(4)烧结；(5)冲压；(6)拉毛；(7)成品。通过本发明制作出的鲍尔环,具有优异的耐酸耐热性能,可在各种高温场合使用,应用范围十分广泛,可用于化工、冶金、煤气、环保等行业的干燥塔、吸收塔、冷却塔、洗涤塔、再生塔等。除熔融金属钠和液氟外,能耐其它一切化学药品,广泛应用于各种需要抗酸碱和有机溶剂的,密封性、高润滑不粘性、电绝缘性和良好的抗老化耐力、耐温优异(能在+250℃至-180℃的温度下长期工作)。(The invention discloses a production method of a polytetrafluoroethylene pall ring product, which comprises the following steps: (1) mixing the raw materials; (2) die pressing; (3) demolding; (4) sintering; (5) stamping; (6) napping; (7) and (5) finishing. The pall ring manufactured by the method has excellent acid and heat resistance, can be used in various high-temperature occasions, has a very wide application range, and can be used for drying towers, absorption towers, cooling towers, washing towers, regeneration towers and the like in the industries of chemical industry, metallurgy, coal gas, environmental protection and the like. Except molten metal sodium and liquid fluorine, the alloy can resist all other chemicals, is widely applied to various products needing acid-base resistance and organic solvents, and has the advantages of high sealing property, high lubrication non-adhesiveness, electric insulation property, good ageing resistance and excellent temperature resistance (can work for a long time at the temperature of between 250 ℃ below zero and 180 ℃ below zero).)

1. a production method of a polytetrafluoroethylene pall ring product is characterized by comprising the following steps:

(1) mixing raw materials: mixing polytetrafluoroethylene and para-polyphenol mixed raw materials, and adding a reinforcing agent, a molybdenum disulfide filler and a fluxing agent;

(2) die pressing: uniformly stirring the mixture obtained in the first step, selecting a pall ring mold, adding the mixture into a mold cavity, performing pre-forming treatment in the pall ring mold, placing the charged mold on a press for pressing, and after a certain pressure is reached, completing the die pressing and forming a compact pre-forming product;

(3) Demolding: demolding can be carried out after the die pressing is finished;

(4) And (3) sintering: after demoulding, putting the mixture into a heating furnace for sintering, carrying out carbonization treatment, and carbonizing the demoulded and molded product for 18-30 hours to eliminate stress;

(5) Stamping: after sintering, carrying out punching operation, punching and windowing pall ring, wherein 4-12 window holes are formed, and according to different use requirements, window holes (rectangular or circular) with different sizes and meeting the required flow requirements in each specification are formed, and the area of the general opening hole accounts for about 30% of the total area of the column wall;

(6) Napping: performing napping treatment on the surface of the stamped pall ring making device by using sanding equipment;

(7) And (3) finished product: and cutting the finished product, and finishing the debugging requirement of the customer on the pall ring according to the requirement.

2. the method for producing polytetrafluoroethylene pall ring products according to claim 1, wherein the sintering process in step (4) adopts gradual temperature rise, the temperature rise is about 16-19 ℃ per hour before 370 ℃, the temperature is kept constant for 4-8 hours after the sintering is carried out to 370 ℃ and the product is transparent, so that the size of the product is ensured, and the diameters of two ends of the column body are required to be the same.

3. the method for producing a polytetrafluoroethylene pall ring product according to claim 1, wherein in step (1), the polytetrafluoroethylene accounts for 65% -85% by mass, the para-polyphenol accounts for 5% -10% by mass, the reinforcing agent accounts for 3% -5% by mass, the molybdenum disulfide accounts for 1.5% -3.5% by mass, and the fluxing agent accounts for 1% -2% by mass.

4. The method of claim 1, wherein the reinforcing agent is glass fiber.

5. The method of claim 1, wherein the fluxing agent is a fatty acid amide.

6. The method for producing polytetrafluoroethylene pall ring products according to claim 1, wherein in the step (2), the extruder is a twin-screw extruder, a heater of the extruder is made of tin-copper alloy, and a barrel and a screw are made of nickel-chromium alloy which is high-temperature resistant, corrosion resistant and wear resistant.

Technical Field

the invention relates to the technical field of pall ring production, in particular to a production method of a polytetrafluoroethylene pall ring product.

Background

the pall ring is improved greatly on the raschig ring, although the outer diameter of the ring is also equal to the height, two rows of windows with inward extending tongues are arranged on the ring wall, and each layer of window holes is provided with 5 tongues. This configuration improves gas-liquid distribution and makes full use of the inner surface of the ring. Compared with Raschig rings, the treatment capacity can be more than 50 percent, and the pressure drop is reduced by half; typically made of metal, plastic or ceramic.

The pall ring packing has the advantages of large flux, small resistance, high separation efficiency, large operation elasticity and the like, and the treatment capacity can be more than 50 percent larger than that of the Raschig ring under the same pressure reduction. Under the same treatment capacity, the pressure reduction can be reduced by half, and the mass transfer efficiency can be improved by about 20%. Compared with Raschig rings, the packing has the characteristics of large production capacity, small resistance, large operation elasticity and the like, the treatment can be 50-100% larger than that of the Raschig rings under the same pressure drop in general conditions, the pressure drop is 50-70% smaller than that of the Raschig rings under the same treatment, the pressure drop of the tower height is reduced, and the Bauer rings can save 20-40% of the volume of the packing compared with the Raschig rings. However, the pall ring manufactured by the prior art has low sealing property, poor electrical insulation and aging resistance and poor temperature resistance, and a production method of the pall ring is needed to solve the problems.

disclosure of Invention

Based on this, there is a need to provide a method for producing polytetrafluoroethylene pall ring products to solve the above problems.

A production method of a polytetrafluoroethylene pall ring product comprises the following steps:

(1) Mixing raw materials: mixing polytetrafluoroethylene and para-polyphenol mixed raw materials, and adding a reinforcing agent, a molybdenum disulfide filler and a fluxing agent;

(2) Die pressing: uniformly stirring the mixture obtained in the first step, selecting a pall ring mold, adding the mixture into a mold cavity, performing pre-forming treatment in the pall ring mold, placing the charged mold on a press for pressing, and after a certain pressure is reached, completing the die pressing and forming a compact pre-forming product;

(3) Demolding: demolding can be carried out after the die pressing is finished;

(4) And (3) sintering: after demoulding, putting the mixture into a heating furnace for sintering, carrying out carbonization treatment, and carbonizing the demoulded and molded product for 18-30 hours to eliminate stress;

(5) stamping: after sintering, carrying out punching operation, punching and windowing pall ring, wherein 4-12 window holes are formed, and according to different use requirements, window holes (rectangular or circular) with different sizes and meeting the required flow requirements in each specification are formed, and the area of the general opening hole accounts for about 30% of the total area of the column wall;

(6) Napping: performing napping treatment on the surface of the stamped pall ring making device by using sanding equipment;

(7) And (3) finished product: and cutting the finished product, and finishing the debugging requirement of the customer on the pall ring according to the requirement.

preferably, the sintering process in the step (4) adopts gradual temperature rise, the temperature is raised by about 16-19 ℃ per hour before 370 ℃, the temperature is kept for 4-8 hours after the sintering is carried out to 370 ℃ and the transparency is achieved, the size of the product is ensured, and the diameters of two ends of the cylinder are required to be the same.

Preferably, in the step (1), the polytetrafluoroethylene accounts for 65-85% by mass, the para-polyphenol accounts for 5-10% by mass, the reinforcing agent accounts for 3-5% by mass, the molybdenum disulfide accounts for 1.5-3.5% by mass, and the fluxing agent accounts for 1-2% by mass.

preferably, the reinforcing agent is glass fiber.

Preferably, the fluxing agent is a fatty acid amide.

preferably, in the step (2), the extruder is a twin-screw extruder, a heater of the extruder is made of tin-copper alloy, and the screw barrel and the screw are made of high-temperature-resistant, corrosion-resistant and wear-resistant nickel-chromium alloy barrels.

the invention has the beneficial effects that: the pall ring manufactured by the method has excellent acid and heat resistance, can be used in various high-temperature occasions, has a very wide application range, and can be used for drying towers, absorption towers, cooling towers, washing towers, regeneration towers and the like in the industries of chemical industry, metallurgy, coal gas, environmental protection and the like. Except molten metal sodium and liquid fluorine, the alloy can resist all other chemicals, is widely applied to various products needing acid-base resistance and organic solvents, and has the advantages of high sealing property, high lubrication non-adhesiveness, electric insulation property, good ageing resistance and excellent temperature resistance (can work for a long time at the temperature of between 250 ℃ below zero and 180 ℃ below zero).

Detailed Description

the following detailed description of the preferred embodiments of the present invention is provided to enable those skilled in the art to more readily understand the advantages and features of the present invention, and to clearly and unequivocally define the scope of the present invention.