|
PROLITE
PLASTICS LTD.
CAUSTIC SOLUTION STORAGE TANK FOR CHLOR-ALKALI INDUSTRY
| Description: |
16'-0" x 13'-6"
high Caustic Storage Tank |
| Contents: |
Caustic Solution |
| Corrosion Liner: |
PP-H 2222 Copolymer
Rolled Sheet |
| Structural Resin:
|
Dow Derakane 411 vinyl
ester resin |
| Construction: |
3/8" thk. hand lay
up shell
3/8" thk. hand lay up top and bottom |
Dual Laminate
Tank Replaces Stainless Steel Tank
In Chlor-Alkali
storage of caustic solutions for cell membrane technologies
stored at 95°C, stainless steel has been traditionally used. The
disadvantage of stainless steel is that it is susceptible to
embrittlement and stress corrosion cracking in the heated
affected zone of the welds. This is caused by low levels of
chloride ions found in the caustic solution that build up over
time at the welds and cause preferential corrosion.
For many years,
chlor-alkali companies have looked for alternative cost effective
materials. In Europe, Polypropylene Block Co-Polymer equipment
has been used in similar applications with service lives of 15
years. Equipment made from Polypropyelene Block Co-Polymer based
sheet, pipe and fittings are ultrapure, flexible, and have a high
weld efficiency. Using Dual Laminate construction, a service
temperature of 95°C can be achieved to safely store 33% caustic
solution.
At the time this
vessel was manufactured, there was no established standard for
dual laminate tanks. This vessel was based on ASTM D3299, a
fiberglass specification for vessels, and adapted for dual
laminate construction. Many of the construction methods used in
manufacturing this tank can be found in the ASME RTP-1 Dual
Laminate Appendix which has been recently released.
This tank has been in
successful operation since 1996.
Back to
Case Histories
© Prolite Plastics Ltd, Feb. 29,
2000
| .jpg)