We often think of filtration systems in terms of ‘dirty’ heavy-duty industries like petroleum refinement, construction, or mining. However, industries like food, beverages, and packaging require filtration processes as well. In packaging, tins, boxes, and bottles are often coloured and printed, and their wastewater therefore contains potentially toxic inks and dyes, as well as traces of metal and shards of glass.
These kinds of contaminants can still be dangerous if they are released into the public sewer system, so the wastewater has to be cleaned and sifted to EPA standards before you pour it down that drain. On the other hand, the edible products that go into these packs need to be rinsed as well. Common procedures include taking mashed grapes out of wine, or fruit pulp out of juice. Wastewater can also be gathered after washing fruit and vegetables before packing them, or boiling them before canning.
These food processes will release wastewater that contains sand, salt, sugars, stones, and various starches. In the early stages of manufacturing, wastewater isn’t toxic, since it mostly contains organic matter, and maybe a few traces of insecticides and pesticides. As the food moves further down the chain, the wastewater might have colouring, flavouring, preservatives and additives, which can all be harmful if they’re not extracted. Below are some of the machines used in filtering food-grade wastewater.
IC45 Centrifugal Basket Filter
The IC45 works by pouring the wastewater into a stainless steel drums that spins inside a cast aluminium case with a solid spring-sealed lid. The filtration process coats the sides of the rotating drum with thick sludge while the cleaned water streams out of an outlet. It’s a popular piece of equipment because of its light weight versatility.
The IC45 can be used individually for small batches of wastewater in a domestic set-up such as a home craft beer brewery. It can also be connected to other manufacturing machines in a large factory such as a snack processor, fruit canner, or commercial winery. For small systems, you can order a manual IC45 whose detachable bowl can be hand-cleaned.
For larger installations, get the automated vertical self-cleaning IC45. It allows the bowl to empty sludge through an external hose without having to stop the filtration process. It can run 24 hours with minimal maintenance, so it’s ideal for factory use. In both cases, the centrifugal basket is powder coated to protect it from food processing chemicals.
Spiral Water Automatic Self-cleaning Filter
In the food industry, wastewater filtration systems are more about separation than actual filtering, because the solid wastes are food grade. Many times, this food paste can be collected and sold as a viable by-product, so it’s not necessarily destined for the incinerator or landfill. The real challenge in food industry filtration is attaining environmental levels of water hygiene.
In many parts of the world, there are stringent standards on the amount of solid particles industrial wastewater can have before it is released into the sewers. Unfortunately, while centrifugal filters are popular, they are often unable to achieve these water particle ratios. Some factories achieve them by using multiple filtration systems, or at least multiple stages.
Often, these multi-step systems start with a vibrating shaker to deposit solid sediment at the bottom of a tank, then move to a rotary drum that uses centrifugal action. Stage 3 is a spiral filter that lets out solids at the top and liquids at the bottom, then finalise with a dewatering system that drains liquid out of the pasty food sludge.
Spiral water filters are automated and self-cleaning. The wastewater goes through the steps often unaided by human operators. Each chamber had a pre-set weight or pressure gauge, and once the programmed levels are achieved, the wastewater moves to the next step. The process is continuous to reduce downtime, and the prior chamber usually cleans itself before receiving a new load. It does this without interrupting the filtration pathway.
Whichever filtration system you select, be sure it fits well with your needs. It should be compatible with whatever equipment you’re already using, and should be efficient and low cost in terms of energy consumption. Pick a model or brand that offers easy access to technical support and servicing teams in case of any problems.