EBNER / Portfolio / Plants / Regeneration of spin bath and production of sodium sulfate in the viscose fiber industry

Regeneration of spin bath and production of sodium sulfate in the viscose fiber industry

(year 2012)

EBNER is specialized in the planning and construction of complete spin bath regeneration plants and has already built a lot of plants worldwide since its company foundation. Due to numerous patents EBNER advanced to become the world market leader for such plants at the end of the 20th century.

For decades already, EBNER-plants are operated in the factory of a viscose fiber producer in Germany for the purpose of spin bath treatment. In the view of this history and the satisfaction of the customer with the available plants, EBNER has in 2012 been awarded the contract for planning, supplying and erecting a plant for spin bath regeneration and production of sodium sulfate from spin bath that has been polluted due to the fiber production process.

In viscose fiber factories, where a chemical reaction takes place during the spinning process in which sodium sulfate and water develop from soda lye and sulfuric acid, the so-called spin bath is exhausted and diluted. In former times this spin bath was used once and then drained as waste water. This caused enormous environmental problems and high operating costs, and made it absolutely necessary to regenerate the spin bath and lead it back into the process, respectively recover a saleable product from the sodium sulfate contained in the spin bath.

For this the following process steps are required:

  1. If necessary, degassing of spin bath
  2. Evaporation of the spin bath
  3. Crystallization of the Glauber’s salt (Na2SO4 * 10 H2O) from the spin bath
  4. Refining of Glauber’s salt to crystalline water-free sodium sulfate by melting crystallization (calcination).

EBNER was awarded the contract for this project primarily due to the comprehensive experiences with EBNER based on a project settled before to fully satisfaction and the outstanding quality of the existing plant. Another reason was the low consumption of primary energy in form of live steam.

Technical data of the entire plant:

  • Feed rate spin bath: 195 m3/h
  • Ingredients solution primarily: Na2SO4, H2SO4, ZnSO4
  • Water evaporation: 38 t/h
  • Product: Na2SO4
  • Production rate: 7,2 t/h

The scope of delivery of EBNER with company-internal personnel consisted, among other things, of:

  • Basic- and Detail-Engineering incl. design of main components
  • Fabrication of main components
  • Erection of the entire plant
  • Start-up of the entire plant