Water Filters Information
Water filters accept liquids of poor or unknown purity and discharge a clear, clean output.
Operation
Water filters remove impurities through finely porous physical barriers and/or chemical and biological processes. Presented in the context of the food industry, this lecture illustrates.
Video credit: Layne Christensen Company
Types
- Granular water filters use sand, anthracite, garnet, or other media to remove impurities down to about 1 micron in size. Activated carbon (adsorption) and ion exchange (softening and deionization) techniques address chemicals/gases and dissolved inorganics respectively.
- Membrane filters capture smaller than 1 micron particles through microfiltration, ultrafiltration, and nanofiltration. Reverse osmosis filters are slow, but can be 90-99% effective. Three general types of membranes are,
- Depth which use absorption or entrapment
- Screens use a set pore size to sort particulates
- Surface membranes are made from multiple layers of media. When fluid passes through the filter, particles larger than the spaces within the filter matrix are retained.
- Distillation and ultraviolet radiation are filtration forms particularly effective against organics. Magnetic filters remove ferrous particles.
Gravity or pressure is used to push the water through the system.
Specifications
- The filtration grade (micron rating) indicates smallest particle size separated (e.g., 5, 75, 300, 600 µm).
- Maximum liquid flow ranges (e.g., 0.5 to 150 GPM).
- Filters operate at a maximum pressure (e.g., 60 to 300 psi).
- Maximum temperatures are set (e.g., 175 to 268 F).
Features
- Duplex transfer valves permit continuous filtration during change-outs.
- Integral bypass valves keep water flowing if the filter gets clogged.
- Spin-on (canister) filters prohibit a system from running without an element in place.
- High delta P indication notifies when the element needs to be replaced.
- Filters and their elements can be portable, reusable/cleanable and/or FDA compliant.
- Tank-mounted filters are attached to reservoirs. In-line filters interrupt a pipeline or hose.
Applications
Water filters are used in residences, municipality treatment plants, and industries such as electronics, biopharmaceutical, food and beverage, medical, pool and spa, and power generation.
References
EPA Science & Technology: Water
Different Water Filtration Methods Explained
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- Alabama
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- California
- Colorado
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- Florida
- Georgia
- Illinois
- Indiana
- Louisiana
- Massachusetts
- Maryland
- Michigan
- Minnesota
- Missouri
- North Carolina
- New Hampshire
- New Jersey
- Nevada
- New York
- Ohio
- Oregon
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- Rhode Island
- South Carolina
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- Activated Carbon
- Anion Exchange Resin
- Bag
- Biopharmaceutical
- Bulk Filter Media
- Cartridge
- Cation Exchange Resin
- Cellulose
- Duplex
- Electronics
- FDA Compliant
- Filter Element / Cartridge
- Food and Beverage
- Glass Fiber
- Housing Only
- Housing and Filter Assembly
- Ion Exchange Resin
- Magnetic
- Medical
- Metal / Porous Metal
- Mixed Resin
- Municipal Water Supply
- Nylon
- PTFE / Teflon®
- Plastic
- Polyester / Fiberglass
- Polyethersulfone (PES)
- Polypropylene (PP)
- Polysulfone (PSU)
- Pool and Spa
- Power Generation
- Pulp and Paper
- Reusable / Cleanable
- Semiconductor Processing
- Steel
- Steel - Stainless
- Synthetic Fiber
- System
- Waste Treatment
- Wire Mesh / Screen
- 50 micron water filter
- demineralizer water filter
- aluminum water filter housing
- humidifier water filters
- in-line water filter assembly
- Powdered Resin water filter
- whole house water water filtration
- 1 water filters
- 10 sediment water filters
- 12v UV water filters
- activated alumina water filters
- activated carbon drinking water filters
- activated carbon industrial water filters
- anion exchange water filters
- aquarium pharmaceuticals tap water filters
- automatic self cleaning filters
- automatic self cleaning water filters
- calcium chloride water filters
- carbon resin water filters
- ceramic monolithic water filters
- colloidal silver water filters
- cotton ball water filters
- cotton wool water filters
- duplex water filters
- electromagnetic water filters
- food grade water filters
- geothermal open loop water filters
- heavy metal water filters
- industrial chiller water filters
- industrial self cleaning water filters