Possible applications
Water treatment: Undesirable substances that damage product quality,
such as nitrate or chlorate, etc., are removed from process water.
Lactose can be concentrated and recovered from the NF permeate
produced during whey processing.
The permeate, which is extremely low in salt and bacteria, has a wide
range of applications in the operational production environment.
Special features of sanitisation with hot water
Hot water sanitisation reduces existing germs and causes slight compaction
of the membrane. This initial compaction is also referred to
as conditioning and ends after the third sanitisation cycle when the final,
stabilised separation and flow performance is achieved. For timecritical
applications that only allow the shortest possible interruptions
in operation – for example, membrane replacement in a production
environment that is still running – it is also possible to purchase preconditioned
membranes ex works.
Practical case study
For the treatment of NF permeate from whey processing, TORAY RO
membranes were compared with other membrane products. For this
purpose, exclusively new membrane modules of all participating suppliers
were operated and evaluated under comparable conditions.
The membrane TORAY TRO 8038 HS showed best results in hydraulic
performance (flux) and separation performance (retention).
The COD in the permeate was 82% lower than the competitor's
product, which means a lower residual load in the permeate and a
significantly higher yield (in this case of lactose).
The operational advantage of hot water sanitisation has even receded
somewhat into the background in view of such a performance
advantage.
Hot water sanitizable and other membrane modules for process
applications are produced at Toray's California manufacturing facility,
certified to ISO 9001:2015 and 14001:2015 to ensure product and
service quality compliance
Buffer tank
Fig 2: Comparison of flow rate Fig 3: NF and RO process
May/June 2021 ¦ international-dairy.com · 19
Comparison of flow rate
TMRO8040HS, weekly santized
NF permeate /
RO permeate / RO inflow
diafiltration qater
for NF system
Silo tanks
Silo tanks
RO
retentate
NF inflow
NF retentate
Flow rate per tube liters/hr
time (week)
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/international-dairy.com
