Outotec Larox® vacuum belt filters
Outotec Larox horizontal vacuum belt filters are formerly known as Pannevis.
The filter housing is designed to easily meet cGMP (current Good Manufacturing Practice) making it especially suitable for pharmaceuticals and biotech products.
Outotec Larox filters are currently used for many pharmaceuticals, both intermediate and final, as well as fine chemicals, bio-products, solvent-processed foodstuffs, solvent wetted organic solids, and pyrophoric materials. With over 120 production scale units installed worldwide, Outotec is the world leader in solvent-based vacuum belt filtration with the Outotec Larox vacuum belt filters.
Outotec larox vacuum belt filters are extremely reliable and maintenance is simple.
Outotec Larox® GT (formerly known as Pannevis) gas-tight filter is a completely enclosed design that can continuously process virtually any solvent based product in a sealed housing, while operating under a continuously re-circulated nitrogen or other inert gas blanket. The filter housing is also designed to easily meet cGMP (current Good Manufacturing Practice) making it especially suitable for pharmaceuticals and biotech products.
Gas tight filters are currently used for many pharmaceuticals, both intermediate and final, as well as fine chemicals, bio-products, solvent-processed foodstuffs, solvent wetted organic solids, and pyrophoric materials. With over 120 production scale units installed worldwide, Outotec is the world leader in solvent-based vacuum belt filtration with the Outotec Larox GT filter.
Outotec Larox GT filters offer all the advantages of the standard RT filter including co- or counter-current washing, reflux washing, vibration, all forms of mechanical compression and either hot gas or infra-red drying. They can be configured in many different combinations of the above options for multi-step processing exactly as the standard RT filters.
The housing is normally operated with a few millimeters of water gauge over-pressure inside. The nitrogen is pulled from the housing during the vacuum stroke by the vacuum pump, where the condensate is removed, and the “dry” nitrogen is then returned to the housing. A very small make-up of nitrogen is required to compensate for nitrogen exiting with the wet filter cake.
The floor and roof of the housing are rounded while the sidewalls are flat. This ensures easy cleaning. Hinged windows in the sides and lights in the roof ensure complete visibility. The windows also provide local access within the housing. Clean-in-place is a standard option and the standard filter is designed for sanitary operation as all dead spots are eliminated, windows and nozzles are angled to drain back into the housing and internal surfaces can easily be polished to a specified level.
The Outotec Larox RT filter is a unique design that offers true multi-step processing on one unit. This one unit provides discrete multi-step processing of a wide range of products, including multiple washing steps, vibration, hot air drying and mechanical compression.
The heart of the Outotec Larox RT filter is a continuously moving filter cloth that does not require a rubber support belt. Instead an open grid located in a profiled tray running the length of the filter supports the filter cloth. The vacuum for separation of the solids and liquid is applied to the underside of the cloth. When vacuum is applied, the forward movement of the cloth pulls the tray with it at the same speed as the cloth. When the tray has advanced to a specified point, the vacuum is briefly removed from the underside of the tray, while, at the same time, the tray is retracted to its original position. Vacuum is then reapplied and the tray again begins to advance with the cloth.
The filter can be used for multiple wash steps, either co-current or counter-current, vibration, hot air drying, cooling, steaming or mechanical compression, any or all such steps in almost any combination. They can also be offered with gas-tight or pressure-tight enclosures, allowing safe operation of processes involving flammable materials, explosives, hazardous materials, or any process where containment is a critical factor. The ability to carry out multiple wash steps, with each wash filtrate precisely collected into its own receiver enables the Outotec Larox RT filter to produce very high purity products with low wash water consumption. Washing can be done with more than one liquid and can be either co-current or counter-current. Very high purity cakes, up to 99.99% or better, can be produced.
The Outotec Larox RT filter is also a very efficient dryer after the dewatering process is completed. Filter cakes are relatively thin, usually between 6 and 100 mm (1/4” - 4”), so drying is achieved quickly with final moisture contents down to 0.1% possible. Rapid drying also allows a higher gas temperature to be used, since the cake will normally not reach the gas temperature except at the end of the cycle. For solvent wetted materials, a gas-tight enclosure with full nitrogen blanketing is used. Equally, steaming or cooling of the filter cake can be accomplished using the drying procedure by substituting steam or a coolant for the hot air.
Outotec Larxo RT filters can be used for the following operations:
- Continuous separation of slurries into filter cake and clear filtrate
- Washing of the filter cake in the following configurations: Co-current washing of the filter cake
- Counter-current washing of the filter cake
- Reflux counter-current washing of the filter cake (coarse materials only)
- Leaching of the filter cake using either co-current or counter-current extraction
- Co-current or counter-current chemical reaction of the filter cake
- Mechanical compression of the filter cake to increase dry solids content using:
- Vacuum Seal Belt Vacuum Press Belt Press Belt Vibration (thixotropic materials only)
- Thermal drying of the cake using:
- Hot gas (air, nitrogen or steam)
Horizontal vacuum belt filters- rubber belt filters
The Outotec Larox® RB-SV is a further development of the Larox RB filter. The vacuum box is located under the rubber belt on the outside edge. For larger width machines (3 m and 4.25 m wide) a box can be mounted on each side of the belt. This offers a number of advantages over the conventional rubber belt concept.
The vacuum box is easily accessible as it is on the outside of the filter. The box is stationary as access for maintenance and cleaning is via removable panels on the box.
The vacuum box acts as the gas-liquid separator eliminating the need for separate vessels. Piping can also be fixed. The overall height of the filter is reduced as there is no requirement for space under the belt for lowering of the vacuum box. There are no holes in the centre of the rubber belt so it can be reinforced across its total width thus increasing belt life.
This is the most diverse application area of Outotec solid-liquid separation products. To assist you in providing the optimal solution for the solid–liquid separation requirements in your particular application, please contact your nearest Outotec office to determine the best possible solution.
- Carboxy Methyl Cellulose
- Citric Acid
- Gypsum (other than Flue Gas Desulphurization)
- Lactic Acid
- Micro-Crystalline Cellulose
- Metal Salts
- Phosphoric Acid and Phosphates
- Pigments and Dyestuffs
- Soda Ash
- Toner (Chemically Produced)
- Zeolites (Synthetic)
Outotec has intensive experience in a very wide range of food-based processes, although we do not normally get involved directly in the primary processing of food.
The below list indicates where we have been successful with our filters. Please contact your nearest Outotec office to further refine your requirement and determine the best possible solution for your application.
- Amino acids
- Carboxy methyl cellulose
- Citric acid
- Edible oils
- Fermentation broth
- Hydrolyzed protein
- Lactic acid
- Tartaric acid/Tartrates
Outotec does not have a large presence in the pharmaceutical market but does have a very important one in the areas where we are present.
As this field tends to be one of extreme confidentiality on the part of pharmaceutical manufacturers, we can only give a general overview of some of the more common applications and indicate the Outotec filters that have been used, but not the applications:
- Fermentation broths
- Pharmaceuticals and intermediates