Nanofiltration (NF): In a classic filtration the liquid filtrate passes through the filter surface only in a perpendicular way. Microfiltration (MF):
Winegrowers Supplies - Crossflow filters, for wine or cider or other liquids.
In a crossflow filtration, where the filter-surface is a semi-permeable membrane, the liquid passes through the membrane and also across the membrane, thus keeping it clean of residues.
According to the membranes pore size this can be referred to as microfiltration, ultrafiltration, nanofiltration or reverse osmosis.
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).
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).
In a classic filtration the liquid filtrate passes through the filter surface only in a perpendicular way.
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.
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 clarifying or pre-filtration.
The crossflow filtration is to a level of around 0.2 microns, which is 'sterile' filtration.
I sell the following models, all of which which have pumps installed:-
EN-F models: the membranes are made of hollow-fibre polypropylene, which allows faster filtration.
The chemical structure of this membrane allows cleaning with solutions either acidic or alkaline. The sanitation of the membranes is vital for protection against bacterial attacks.
They have been building these filters for 10 years and have never replaced any membranes. Used correctly, the membranes have a very long life. A membrane costs about 4,000 Euros.
They do not incorporate a pre-filter, it is not necessary.
The liquid to be filtrated must be free from potassium bitartrate crystals and clarifying material such as bentonite, it must be clear but not necessarily pre-filtered.
The exclusive system 'Reflux' is automatic, during the filtration, and small cycles of washing of the membranes against the flow.
Reflux doesn't involve any loss of time or hourly production. It is carried out without interrupting the cycles of work, allowing more efficient use of the filter, and minimising the number of washings, it also lengthens the life of the membranes.
Oxidation of wines or cider is the most serious risk that faces the user of tangential crossflow filters.
These EN-F models achieve all the phases of 'Reflux' using inert Nitrogen gas, both for the management of the flows of liquid and for the highest protection from oxidation.
They use the Nitrogen to make automatic counter-flows that keep the membranes efficient for a long time before washing is necessary.
Th gas used is expelled automatically from the filter, it is sent partly to the tank of filtered liquid and partly to the tank of liquid still to be filtered.
This filter does not change the colour of the liquid being filtered, which is an advantage.
If you want to remove colour, it can be done by treatment with activated carbon before filtration.
Management with PLC is incorporated as standard, not an optional extra.
The PLC achieves automation to the highest level. All the parameters for a job and all the functions of the filtration are managed with a microprocessor.
The levels of pressure, of flow, of temperature and of efficiency, are constantly available on screen to the operator. Any anomolies are quickly seen.
The same happens during the delicate phases of washing and maintenance of the membranes.
Pumps, tubes, valves and reservoir are all in stainless steel. DIN40 connectons, maximum liquid temperature is 50 °C.
These filters have membrane modules with a filtration surface of 13 sqm each; although they state 10 sqm it is actually 13 sqm.
Model EN-F10: 250 to 1200 litres/hour, one membrance, 10 / 13 sqm, 2.88 kWatt, 600 mm x 1200 mm x 1950 mmH, 21,000 Euros
Model EN-F20: 500 to 2400 litres/hour, two membranes, 20 / 26 sqm, 3.50 kWatt, 600 mm x 1200 mm x 1950 mmH, 32,550 Euros
Model EN-F30: 750 to 3600 litres/hour, three membranes, 30 / 39 sqm, 4.68 kWatt, 1000 mm x 1500 mm x 1950 mmH, 40,950 Euros
Larger/faster models are available, prices on request.
Delivery is normally 4 to 7 weeks.
Model IND-B1: 300 to 900 litres/hour, one PPE membrance 15.3 sqm, 1.2 kWatt/hour, 800 mm x 900 mm x 1600 mmH, 170 Kilos, 23,620 Euros
Model IND-B2: 600 to 1800 litres/hour, two PPE membranes 30.6 sqm, 2.5 kWatt/hour, 1000 mm x 1000 mm x 1700 mmH, 280 Kilos, 38,560 Euros
They are all built with DIN40 threads, and normally the internal diameter of the hoses must be 40 mm. For the smallest model (IND-B1) 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.
The maximum liquid temperature is 40 °C.
Double pre-filtration unit at entry, in stainless steel, 377 Euros
the second pre-filter is made of stainless steel, not just with a plastic housing.
Non retentate unit, 433 Euros
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.
Upgrade to Electronic Flow Meter, 1037 Euros
Upgrade to PLC - electronic process control - touch 3.5", 3,940 Euros
The electronic flow meter is used for monitoring the flow rate of the filter. This type of flow meter is also in communication with the PLC (if installed).
In that case its possible to stop the unit automaticly after a certain number of litres. Thats useful if the unit is left to work unsupervised.
For example. you wish to filtrate from one tank with 20,000 litres into another tank, but filtrate only 10,000 litres and then stop.
Or, if you would like to filtrate from a tank back into the same tank, for example to slow down a fermentation.
In either case you can set a certain number of litres and after that the unit will stop on it's own.
For cleaning, normally it's sufficient to rinse well with water, for occasional cleaning I can supply: Henkel Ecolab Ultrasil 69 New, 26 kilo pack, 260.00 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.