Winegrowers Supplies  -  Crossflow filters, for wine or cider clarification, and many other applications

In a classic filtration the liquid filtrate passes through the filter surface only in a perpendicular way. In a crossflow filtration, where the filter-surface is a semi-permeable membrane, the liquid passes through the membrane and also across the membrane and thus keeps it clean of residues. According to the size of the membrane’s pore size this can be referred to as microfiltration, ultrafiltration, nanofiltration or reverse osmosis.

Microfiltration (MF):
A low-pressure process for the retention of suspended material particle size of 0.01 microns or larger.
Smaller particles (salts, sugars and proteins, for example) pass through the membrane. Typical operating pressures range from 5 to 45 psi (0.34 - 3 bar).

Ultrafiltration (UF):
A medium-pressure process offering retention of proteins, colloids and biological material including particles 0.005 microns or larger (molecular weight greater than 1000 Dalton).
Typical operating pressures range from 7 to 150 psi (0.48 - 10 bar).

Nanofiltration (NF):
Water and monovalent ions, as well as low molecular weight substances (less than 250 Dalton) pass through nanofiltration membranes.
Divalent or multivalent ions, such as divalent salts, are retained. Operating pressures between 120 and 600 psi (8 - 41 bar) are typical.

Reverse Osmosis (RO):
A high-pressure process that retains almost all particles and ionic species, while water and some organic molecules pass through. Substances with molecular weight above 50 Dalton are retained almost without exception.
Operating pressures are typically between 300 and 850 psi (21 and 59 bar), but may exceed 1100 psi (76 bar) in some applications.

In conventional filtration the feed flow is perpendicular to the membrane surface, which causes a buildup of debris that eventually reduces fluid permeation.
In crossflow filtration, flow is tangential to the membrane surface resulting in a continuous scouring action that almost eliminates formation of a membrane fouling layer from feed-stream debris and macro molecules.
Driven by pressure in the filtration modules, part of the liquid passes through the membrane. This fraction is called "permeate" or "filtrate," while the fraction that does not pass through the membrane is called the "retentate" or "concentrate".
The end product may be:-
  - the permeate, as in fruit juice clarification or effluent purification,
  - or the retentate, as in the concentration of antibiotics.
In some cases, both streams – permeate and retentate – will be valuable end products.
Depending on the size and type of the particles or solutes contained in the feed stream, there is a wide range of separation processes available.

• Single filtration of raw products.
• Production of wines with residual sugar.
• Prevention of malolactic fermentation.
• Improvement of tartrate stability.
• Filtration of sparkling wines.
• Recovery of second pressings.

Main Features:-
• Continuous running – 24 hour filtering cycles.
• Reduced labour – automatic system.
• Constant flow rate – predictable processed volumes.
• Operational reliability – operator mistakes are avoided.
• Saving in production costs – clarifying substances and filtering aids are not required.
• No waiting for clarification in tank – fatser tank turnover (fewer tanks needed).
• Integral product recovery – lowest unfiltered volumes (0.2% of total volume).
• Saving in energy – about 0.09 kWatt per 100 litres of filtered product.
• Economic – cost is about 0.18 Euros per 100 litres of filtered product.

Note: the crossflow filter is not suitable for filtering liquids containing a lot of solid particles. It should be used only after an clarifying, pre-filtration etc.
After the crossflow filtration the juice is completely clear, at around 0.2 microns.

I sell the following models, which have a pump installed:-

   Model IND-700 (up to 700 litres/hour, 15.3 sqm membrane, 1.2 kWatt/hour, 800 mm x 900 mm x 1600 mmH, 180 Kilos.), 20,450 Euros

   Model IND-1300 (up to 1300 litres/hour, 30.6 sqm membrane, 2.5 kWatt/hour, 1000 mm x 1000 mm x 1700 mmH, 280 Kilos.), 33,460 Euros
    Double Prefiltration unit at entry, in stainless steel, 352 Euros
    Non retentate unit, 415 Euros
    Upgrade to Electronic Flow Meter, 990 Euros
    Upgrade to electronic process control - touch 3.5", 2,500 Euros

They are all built with DN40 threads, and normally the internal diameter of the hoses must be 40 mm. For the smallest model (IND-700) it's allowed to use 32 mm internal diameter hoses.

For the hose fittings: normally three are needed:-
  1) inlet: (in aspiration) cloudy liquid flowing in from the source tank.
  2) clear outlet: filtered liquid flowing out, to another tank or ...
  3) return outlet: returning unfiltered liquid to the source tank.

In the filtering process, part of the liquid is filtered and part is not filtered, that part normally returns to the source tank.
With the optional 'non retentate unit' the return outlet is replaced with a stainless steel pipe which returns to the inlet (aspiration) side, recirculating the liquid immediately.
It's possible to remove the 'non retentate unit' and fit a hose to return the unfiltered liquid to the source tank.

Normally it's sufficient to rinse well with water, for occasional cleaning: Henkel Ecolab Ultrasil 69 New, 26 kilo pack, 172.00 Euros

Larger/faster models are available, prices on request.

Delivery is normally 4 to 6 weeks.

Prices shown are exclusive of Vat.
Delivery usually will need to be charged at cost.