ANDRITZ heat recovery unit (HRU) for refiner steam
The TMP heat recovery unit has a special non-fouling design that captures heat from refiner vapors and recovers turpentine.
In mechanical pulping, wood chips are refined under elevated temperature and pressure requiring large amounts of mechanical energy. Approximately 70–80% of the total energy input is released in the form of water vapor. Some mills still "waste" this energy by condensing the released vapor with cooling water. However, this energy can be captured and used to generate fresh steam in an ANDRITZ heat recovery unit (HRU).
TMP vapor is very difficult to handle because it is heavily contaminated with fiber and contains large amounts of NCG gases (mostly air in the chips). The unique design of the ANDRITZ reboiler handles the difficult TMP steam without plugging:
- Pressurized TMP systems generate low pressure steam
- Atmospheric systems generate vacuum steam
With a pressurized refiner, enough energy can be recovered to meet the needs of the drying system. The TMP heat recovery system produces low pressure steam for pulp drying while the turpentine released in the process is recovered at the same time. This reduces VOC release into the atmosphere while offering excellent economics.
- Easy to operate
- Non-plugging, handles difficult TMP vapors
- Less cooling water required, thermal energy generates steam
- Recovers turpentine
- Other contaminants are captured in much smaller condensate flow