Solutions - Application

Heat exchanger

Although fluoropolymer has poor heat conduction, fluoropolymer coating is selected in some cases in this field. For example, comprehensive heat transfer and washability can be advantageous of the fluoropolymer coating for heat transfer plates with severe adhesion of process liquids. Another merit of using fluoropolymer coating is it can be used under negative pressure condition, and also expected to keep the high purity of process chemicals.

Anti-corrosion, high purity specification multi-tubular heat exchanger with bake type fluoropolymer coating

NIPPON FUSSO has developed heat exchanger with bake type fluoropolymer lining "NFX-2700" onto all liquid and gas contact areas. Heat exchangers in manufacturing equipment require anti-corrosion and high purity properties and existing fluoropolymer mold cannot be used under pressured and negative pressured. "NFX-2700" is special specification which has high purity lining film inside of thin heat exchanger tubes which is also compatible with positive and negative pressure.

Features of multi-tubular heat exchanger with bake type fluoropolymer lining

  1. Excellent anti-acid and anti-alkali, available to multi-purpose use.
  2. Excellent high purity.
  3. No crack against impact.
  4. Prevent scaling.
  5. Usable under positive and negative pressure.
  6. Compatible with pressure vessels.
SPECIFICATION
Lining Specification Tubes : NFX-2700 (FEP polymer/PFA polymer)
Chamber and Plates : NF-240 (FEP polymer/PFA polymer)
Lining Film Thickness NFX-2700 : 300 to 500 µm
NF-240 etc. : 500 µm to 1.0mm
Overall Heat Transfer Coefficient Liquid-Liquid : 250 to 300 kcal/m2·hr·°C (400 to 500kcal/m2·hr·°C actual performance)
Liquid-Gas : 50 to 150 kcal/m2·hr·°C
Design Temperature 150°C Maximum
Shell side Design Pressure Full Vacuum to 0.5 MPaG
Substrate of Main Body and Tubes SUS series
Size of Tube from Φ19mm
Coefficient of Thermal Conductivity
(Theoretical Values) 		Stainless Steel : 16 w/m·k
PFA polymer : 0.19 w/m·k
FEP polymer : 0.20 w/m·k
ETFE polymer : 0.24 w/m·k

* The substrate of heat exchanger is designed and fabricated by Kimura Chemical Plants Co., Ltd.

* Chemical engineering calculation is available as reference.

Actual application examples

Non-stick specification multi-tubular heat exchanger with bake type fluoropolymer coating

NIPPON FUSSO has developed multi-tubular heat exchanger with bake type fluoropolymer coating, with non-adhesion specifications. This multi-tubular heat exchanger is coated with FEP coating, excellent non-stick property, meaning it has much higher non-stick and washability than metal multi-tubular heat exchangers. This results in faster cleaning time and reduction of solvent for cleaning, which reduces costs and environmental burden.

Features of multi-tubular heat exchanger with bake type fluoropolymer coating

  1. Almost the same level of thermal conductivity can be achieved as a 6mm thick stainless steel plate.
  2. Not affected by ethyl acetate, toluene, NMP, etc (tested).
  3. Coating is possible for multi-tubular heat exchangers currently in use. *Please inquire in advance.
  4. PFA coating is also possible. *Please inquire in advance.

Solvent resistance test results

NFX-0464 sample panels were soaked in ethyl acetate, toluene, and NMP for two months at room temperature. Then, a spiral scoring test (in accordance with JIS K 6894) was conducted, and evaluation scores of 5 out of 5 (passing scores) were achieved for all.

  • Ethyl acetate
  • Toluene
  • NMP
Test conditions and results
Coating NFX-0464 (approx 30µm) none
Substrate SUS304(thickness 6mm)
Test Equipment Yamazaki method lining tester
(LA-15)
Figure: Summary of heat transfer characteristic test
Figure: Heat transfer characteristic test results

The test results showed that the top two panels had almost equal heat transfer characteristics. Therefore, it can be considered that the thermal conductivity for NFX-0464 is approximately equal to the 6mm thick SUS304.