Larox DS Series Automatic Pressure Filter proves its worth for fine particle size products

Larox DS Series Automatic Pressure Filter proves its worth for fine particle
size products where cake washing combined with the driest possible cake are
required 

LAPPEENRANTA, FINLAND - January 10, 2007 - The Larox DS Series filter is a
totally enclosed design of vertical automatic pressure filter that utilizes a
unique polypropylene plate design to enable filtration of difficult materials
in a contained cleanable environment. Several large orders over the last few
months have proven the suitability of the Larox DS for fine particulate
products where cake washing is critical and the filter cakes need to be as dry
as possible when discharged. 

Larox has booked orders in the last 12 months from 6 different clients for 8
Larox DS automatic pressure filters ranging from 7.2 up to 117 m2 filtration
area. In each case the major reason for the selection of the equipment was
successful filtration and washing of filter cakes averaging below 5 µ particle
size. In one case the application is a bio-pharmaceutical process and the
filter will be used on several steps in the process. In another application the
product is in the liquid phase and the DS produces high clarity filtrate
leading to improved downstream performance and higher yields. 

The success of the filter is a result of the design of the filter chamber. Each
chamber has a filtrate collector plate on both the upper and lower side, each
covered with a section of the endless filter cloth. This ensures double sided
(DS) filtration as the filter cake forms on both the upper and lower sides of
the chamber as the slurry is fed into each filter chamber. After successful
filtration, the cake washing and subsequent squeezing and blowing can be
configured to provide the optimum product. 

Several different washing options are available with the Larox DS Series
including slurry channel washing (via the slurry feed line), corner channel
washing (from top of the cake down and across) and counter-flow washing (from
the bottom of the cake up and across). This ensures the best wash result with
the least amount of wash liquid and can be optimized to each product. The most
difficult washing requirements can therefore be carried out efficiently at low
cost. 

The high squeezing pressures used after washing lead to lower residual
moistures compared to other filtration processes. When combined with high
pressure blowing of air or nitrogen through the cake during the squeezing step,
the residual moisture can be reduced even further. 

The filtration chamber design is also perfectly suitable for slurries that
filter slowly. The fail-safe design effectively causes the chamber to expand as
the filter cake forms. By using both chamber sides to build up the cake it
reduces the number of chambers required, as thinner cakes build on double the
surface area. The horizontal configuration of the filter plates ensures an even
cake build-up on both sides and, as a result of this even cake structure the
optimum conditions are created for subsequent process steps. 

The filter cakes all discharge to the same side of the filter. During discharge
the integrated cloth-washing system cleans the filter cloth with high-pressure
water preventing the cloth from blinding and ensuring consistent filtration
conditions. 

The Larox DS Series filter is an enclosed design that can also be configured
for hygienic processes and can also be made totally Gas Tight to operate under
an inert nitrogen atmosphere for solvent wetted or flammable processes. For
foodstuffs and pharmaceutical intermediates a full CIP (clean-in-place) system
is a standard feature and ensures total cleaning of all parts of the filter,
including both sides of the filter cloth and the filter plates. 

Applications to date include white minerals and zeolites, dyestuffs and
pigments, intermediate pharmaceuticals, fermentation broths, enzymes, yeasts,
foodstuffs and fine & specialty chemicals. 

With filters ranging from 1.8 to 160m2 filtration area in three filter plate
sizes; 800 x 800, 1200 x 1200 and 1200 x 2400, there is a Larox DS filter to
meet any application. 

About Larox Group

Larox Group is a leading innovator of solid/liquid separation solutions for the
world's process industries. Companies in mining and metallurgy, chemical
processing and related industries benefit from Larox's high-performance,
high-efficiency process solutions, technologies and products. Larox serves its
global client base through its extensive network of sales and service offices,
and representatives worldwide. Larox is headquartered in Lappeenranta, Finland. 

For more information please contact:

Larox Corporation
P.O. Box 29
53101, Lappeenranta,
Finland

Phone +358 5 668 811
Fax +358 5 668 8277
E-mail info@larox.com
Internet www.larox.com