The MBR Book: Principles and Applications of Membrane

Other
equipment
1.11%
Process
air blowers
34.68%
Mixers
4.42%
Process pumps
5.37%
Recirculation
pumps
15.84%
Vacuum pumps
0.39%
4.3.2 Mitsubishi Rayon Engineering
Membrane
aeration
blowers
38.17%
Membrane
replacement
8%
Chemicals
15%
Energy
37%
(a) (b)
Commercial technologies 179
ZENON
equipmen
purchase
price
40%
Figure 4.17 Representative costs for: (a) energy demand and (b) life cycle for the Zenon MBR system
(5.7 MLD plant)
Mitsubishi Rayon represents the third largest MBR membrane supplier worldwide,
with respect to installed capacity, after Zenon and Kubota. Mitsubishi Rayon
Engineering (MRE) was spun out of the Mitsubishi Rayon Company Limited in
1975. The company, which has a turnover of around $330 million, operates in a
number of areas relating to polymeric materials, and their product range includes
membrane filtration as applied to both the industrial and municipal sectors. They
first introduced an MBR membrane product in 1995 and, as of March 2005, the
company had over 1500 of its systems installed worldwide, over 900 of these being
in Japan. Its commercial profile is thus similar to that of Kubota.
There are currently two Mitsubishi Rayon elements. The first, based on the company’s
existing Sterapore PE HF membrane, comprises horizontally oriented filaments
of 0.54 mm outer diameter (o.d.) and 60–70 �m wall thickness (Fig. 4.18a).
For this membrane, slit-like pores (Fig. 4.18b) of nominally 0.4 �m are generated by
stretching to produce a simple isotropic membrane material. The fibres are potted
with polyurethane resin at either end within ABS plastic permeate collection pipes
to form 1.5 m 2 SUR234L or 3 m 2 SUR334LA SteraporeSUN elements (Fig. 4.18c).
The larger area element is wider (524 mm vs. 446 mm), the other dimensions being
the same for the two elements: 1035 mm high by 13 mm thick.
Elements are mounted within a stainless steel frame to form units containing up to
70 elements, providing a membrane area of up to 210 m 2 for the larger element.
Modules can be either single (Fig. 4.19a) or double deck (Fig. 4.19b), with permeate
withdrawn from each deck. The largest (i.e. 210 m 2 ) single-deck module is 1538 mm
wide � 1442 mm high � 725 mm deep and weighs 184 kg. A standard net flux of
10 LMH is recommended for this membrane based on a cycle of 9–13 min filtration/
2–3 min relaxation and operating between TMP limits of 0.1 and 0.4 bar. The modules