Water filtration applications in a Food and Beverage facility
In a typical Food and Beverage facility there are many different water and process applications, each demanding its own specific level of water purity. The presence, flows and purity of each of these streams is driven by the Food and Beverage plant design, e.g. canning, dry-goods, soft-drink, brewery.
These can include:
- Pre-treatment of well, surface or city water
- Boiler water treatment
- Condensate treatment
- Process water treatment
- Cleaning and sterilization service water
- Hygiene Services
- Waste water disposal.
Regardless of the application, there is a good chance that some type of industrial water filtration will be required in order for the Food and Beverage application to operate at its peak efficiency.
Defining the Types of Water Filtration Systems
Water filtration options can be divided into two major categories, based upon the filtering media used
- granular and
Granular water filtration has been used for many decades in the Food and Beverage Industry, and will be familiar to most. Examples of granular media filtration include sand filters; activated carbon filters for taste, odor, and chlorine removal; anthracite filters; and fine garnet filters.
These types of filters can remove suspended particles down to about 10 microns in diameter (1 micron = 10-6 meters). With the use of certain coagulant or flocculation polymers fed prior to these filters (fed as filter aids), some success has been seen in the removal of particles down to almost 1 micron.
The spacing between the discrete filtering media particles serves as the pores. Suspended solids trapped out by these filters will be collected on top of the filtration media bed, or within the pores.
Membrane water filtration uses membranes to remove suspended particles. Unlike granular filters, the membranes are designed with pores and are capable of removing much smaller particles. The ultimate membrane filtration is reverse osmosis (RO), where dissolved solids (metal ions) can be removed. This is not really a filtration mechanism in the truest sense of the words, as the semi-permeable membranes used in RO do not have pores. It is more properly thought of as a demineralization mechanism.
Membrane water filtration is best characterized by the size range of the filterable particles, as follows:
- Microfiltration (MF) can include woven or wound depth-type cartridge filters, or true membrane filters. Can remove particles from about 0.1 micron to over 1 micron.
- Ultrafiltration (UF) can remove particles from below 0.01 microns to over 0.1 microns. Can remove some large molecular weight organic dissolved material.
- Nanofiltration (NF) can remove particles from below 0.001 microns to 0.01 microns. Can remove smaller molecular weight organics.
- RO can remove particles from 0.0001 microns to 0.001 microns. Can also remove DISSOLVED IONIC SOLIDS.