Liquid filters are porous devices that help filtration systems achieve their goal, which is to remove target particles from a fluid stream. The liquid filtration process as a whole seeks to acquire the filtered materials and/or clear the liquid. There are many, many different types of filters that meet the needs of the many industries that require their services, industries such as automotive, cosmetics, chemical processing, electronics, food and beverage processing, marine, medicine, oil and petroleum, paper and pulp, pharmaceuticals, printing, photography, and textiles.

The term “liquid filters” can refer to an entire filtration machine, to the holding device of a filtration machine, or to filtration media. Let’s break each one down. There are three main types of liquid filter machines: water treatment plant filters, point-of-use filters, and portable liquid filters.

Water treatment plant filters are those filters that provide liquid filtration on a large scale. These liquids can be water, chemicals, oils, or other types of fluids. Types of filters used for this type of work include biological filters (ex. algae filters), cloth filters, disk filters, media filters, screen filters, and slow sand filter beds.

Next, point-of-use filters are filters for at-home use. Filters like these include: carbon filters, depth filters, metallic alloy filters, and microporous ceramic filters.

Finally, portable filters are used by hikers, the military, humanitarian aid teams, and the like. These filters are quite small; they can be operated via a siphon drip system or a mechanical pump, or they can be built into water bottles. Siphon drip filters work by forcing dirty water up into the system to be cleaned and then letting gravity pull it down again, into a different area, while mechanical pump filters are operated by mechanical pumps.

Filters built into water bottles consist of a screen-filtered, flexible silicon tube and a specialized filter through which the water is pumped. These types of filters usually target contaminants like protozoa, microbial cysts, and other kinds of disease-causing bacteria that may be found in dirty water. Read More…

Leading Manufacturers

Precision Filtration Products

Philadelphia, PA | 215-679-6645

Shelco Filters

Middletown, CT | 800-543-5843

All-Filters, Inc.

Reno, NV | 775-825-7600

Sterlitech Corporation

Kent, WA | 877-544-4420

The device holding a filter has a few different names, such as filter housing, filter holder, filter frame, and filter cartridge. These devices may be purchased separately and used to update or build small filtration systems. Filter holders are good for use with applications that require or recommend customizable or easily replaced parts. Usually available in steel, stainless steel, aluminum, or thermoplastics, filter frames are usually fully disposable. In addition to being available for purchase in parts, customers may also find them as preassembled units, already paired with filter media. The preassembled option is a good choice for those seeking efficient installation, use, maintenance, and replacement.

Filter media itself is the material that makes the filter actually work. It is the chemical, mat, or barrier that assists in cleaning the liquid. Media includes organic and synthetic materials. Organic media materials include carbon, granite, sand, peat, and more. Among popular synthetic media are spun materials, such as microfiber and multifilament mesh, both of which can easily be physically modified to fit different filter types.

To meet the vast array of needs on the filter market, manufacturers create a number of different specialized and semi-specialized liquid filters for certain applications. Broadly, however, all of these can be categorized by the type of filter media they use. The three main media categories are: chemical, mechanical, and biological.

The chemical filter is defined as any type of equipment that can be used to separate specific materials out from a liquid via a chemical change. This type of filter, which includes strainers, cartridge filters, and bag filters, clarify liquid using absorbents like ion exchange resins and activated carbons. Chemical filters are the preferred filter for applications involving solute purification.

The media of mechanical filters, on the other hand, is inert. Instead, they remove impurities by either physically or mechanically straining them. Mechanical media is available in a variety of porosities, from very coarse to extra fine. Mechanical filters are usually long-lasting, as long as they are regularly cleaned.

Biological filters use media that is both inert and able to house good bacteria. Bacteria is important to this filtration process, as it helps break down the toxicity of dissolved solids. Biological filters should not be replaced unless they become to clogged to work.

Some specialized liquid filters include biodiesel filters, coolant filter systems, gas filters, and hydraulic filters, which are all used to improve mechanical efficiency and the recycling capabilities of businesses that use fuel. Micro-filtration systems and ultra-filtration systems are both designed to filter exceptionally small particles. They can filter out compounds as small as .1 µm or .001 µm, respectively. Quantity-specific filters include high-flow filtration systems and low-filtration systems.

Bearing filters are designed specifically to filter lubrication oil. When selecting a filtration system, interested parties should consider: type of flow, media material, particle size, temperature, load capacity, stream composition, ply, accuracy, absorption, size, porosity, pressure drop, and batch operation. For questions and in order to make the best decision, it is recommended that they seek out an experienced filtration specialist.

Liquid Filter Informational Video