logo

Home> What's New > December 3, 2018

What's New banner

December 3, 2018 New Technology Registered on JS Innovation Program Advanced rotary pressure dehydrator reduces LCC and CO2emissions

Japan Sewage Works Agency (JS) has been running JS Innovation Program* since 2011. The program aims to encourage the development of new technologies that meet various needs of municipal wastewater business and facilitate the adoptions of the innovative technologies to our entrusted projects.
JS adds the following new technology on JS Innovation Program.

Type 3 Rotary Pressure Dehydrator
  • Developer:
    JS, Tomoe Engineering Co., Ltd.
  • Technology Summary:
    A conventional Type 2 rotary pressure dehydrator is mostly used for the dewatering of mixed raw sludge. Type 3 rotary pressure dehydrator was developed to improve dewatering performance of Type 2. The new dehydrator has two additional functions of electric conduction and two-agent sludge conditioning. Compared to the conventional dehydrator, the promising new hydrator having an improved dewatering performance can be expected to reduce LCC and CO2 emissions.

* Note that JS Innovation Program verifies registered technologies for their applicability only at JSf entrusted projects.


Type 3 rotary pressure dehydrator retains many advantages of type 2 dehydrator such as simple structure, light weight, small footprint, sealed structure, and requiring small amount of washing water. The new dehydrator has been added new functions of electric conduction and after-adding of polyferric sulfate to achieve further dehydration of sludge.

The common mechanism of dehydration between Type 1, 2, & 3 Rotary pressure dehydrator

vertical restrictor

New function

electric, polyfeffic sulfate combination

*Reductions of water content rate are compared values with type 2 dehydrator.


Flow diagram


Targeted sewage sludge


Mixed raw sludge that is generated through the conventional activated sludge (CAS) process and mechanically thickened

* Researchers verified the dehydration performance of the new dehydrator for some kind of the untargeted sludge by test machines.

Recommended conditions

  • Small space for installation
  • The building with a dehydrator has limited load resistance
  • The suppliable washing water is limited
  • Air volume for deodorization is limited
  • Cake disposal cost is expensive because sludge has high water content rate

Example of application