Production process of fluorine plastic graphite heat exchanger

Abstract

The invention discloses a production process of a fluorine plastic graphite heat exchanger. The production process includes the following steps that (1) the dried graphite block is placed into a vacuum tank to remove the organic solvents and the moisture, and the drying temperature is 380 DEG C*2hr; (2) the FEP emulsion impregnation is conducted: vacuumizing is conducted on the vacuum tank in thestep (1), the vacuumizing is up to -0.1 MPa, the FEP emulsion is sucked into the tank by using the negative pressure, the vacuum degree is maintained at -0.1 MPa*1H, compressed air switching is conducted, the pressure is maintained at 0.8 MPa*1H, drying is conducted for 210 DEG C*3H, and the cycle impregnation is conducted by 5 times according to the methods in the step (2); (3) the PTFE emulsionimpregnation is conducted: the graphite block and the PTFE emulsion are put into the tank in sequence to be sealed and vacuumized in sequence, each of -0.03, -0.06, -0.10 MPa is maintains for 20 min,compressed air switching is conducted, the pressure is maintained at 0.8 MPa*1H, and drying is conducted for 250 DEG C*3H; and (4) sintering is conducted: sintering is conducted on the graphite blockafter the PTFE emulsion impregnation in the step (3), the sintering temperature is 320-360 DEG C, the sintering is conducted for 15-25 min, and the final product is obtained after cooling. The production process is simple and easy to operate, the produced graphite heat exchanger has higher pressure resistance, and the problem of PTFE shedding is effectively solved.

Description

technical field [0001] The invention relates to a graphite heat exchanger, in particular to a production process of a fluoroplastic graphite heat exchanger. Background technique [0002] Graphite heat exchangers are heat exchangers made of graphite for heat transfer components. The graphite used to manufacture heat exchangers should be impermeable. Impregnated impermeable graphite and pressed impermeable graphite are commonly used. Graphite heat exchangers are mainly used For stainless steel cleaning and petroleum nitration treatment, the main solution is to impregnate graphite blocks with phenolic resin and furan resin. Because nitric acid, sulfuric acid, hydrofluoric acid, dichromic acid, etc. with an acid concentration exceeding 70% often appear in this industry at present, but these two resins have the problem of insufficient corrosion resistance, resulting in high maintenance and replacement costs. [0003] Therefore, it is proposed to use fluororesin to improve the de...

AI Technical Summary

Problems solved by technology

Because nitric acid, sulfuric acid, hydrofluoric acid, dichromic acid, etc. with an acid concentration exceeding 70% often appear in this industry at present, but these two resins have the problem of insufficient corrosion resistance, resulting in high maintenance and replacement costs

[0003] Therefore, it is proposed to use fluororesin to improve the development of corrosion resistance. In the early stage, PTFE emulsion was used for impregnation, but there were insufficient bonding between PTFE and graphite, and the defects of low pressure resistance. In order to improve the pressure resistance and improve the problem of PTFE falling off, a The production technology of this kind of graphite heat exchanger has become a technical problem to be solved urgently by those skilled in the art