We come across filters every day in one form or another. Now and then, we come across them in obvious locations; other times, they hide inside different pieces. Generally, filters were developed to enable total removal of impurities like sediments, dirt, electromagnetic interference, bacteria, and chemicals among fluids.
Some people believe that filters are only used in decontaminating gases and fluid, but it's far from the complete truth. With the growth and advancement of modern technologies, filters can discard things as complex as optical and electrical problems. In this article, we'll examine a list of varying filters and where you might likely need them.
What are the types of filtration? (Types of filters)
The major work they do happens to be the purification of the air that flows through any medium. An air filter is a fibrous entity that eliminates gaseous and even solid impurities from incoming air. It has diverse applications, from engineering to even medicine. Industries first have to cleanse the fume-filled air they produce before letting it flow into the surroundings, to avoid a severe health crisis.
This equipment comes in diverse forms and dimensions, and it is dependent on the features of the machine they fit into possesses. Air filters discard varying impurities like exhausts, lubricants, germs, and dirt.
An air filter comprises basically of two parts – a filter element that is built specifically to match the equipment they fit into, and a casing that houses the filter. Vital requirements considered before assembling an air filter include the filter characteristics as well as the dimension, type, filter medium, rate at which the air flows (flow rate), and the planned use or application.
Appliances that incorporate air filters in their designs include:
- Automobile engines.
- Vacuum cleaners.
- Air conditioners.
This equipment is designed to fit perfectly along an engine's fuel line. Their main job happens to be the complete eradication of small particles and fluid impurities like water and oil. A standard fuel filter serves the function of getting rid of dust gathered over a while in an internal combustion engine. These filters have cartridge like designs, having the filter paper placed inside the cartridge.
Fuel filters serve a crucial purpose in eliminating rubble from an internal combustion engine. If these impurities enter the engine, they might, in a short while, cause rapid wear and tear, causing untimely fuel pump and injector failure.
The main requirement when assembling a standard fuel filter includes dimensions of the filter, filter type, filter medium, flow rate, and the planned use. Fuel filters are built with their overall dimension being a key factor in maximizing their efficiency.
Not designed like other filters, as the name implies, these pieces of apparatus are circuits whose primary purpose entails classifying series of electronic signals, discarding interfering and undesired frequencies, while enhancing the frequencies needed.
Electronic filters work best under radio frequency (RF). The range of frequencies they function in is between audio frequencies and intermediate frequency.
The primary functions for these filters include:
- High and low pass
- Analog and digital.
- Passive and active.
Electronic filters are also used to minimize or completely eradicate electrical sounds.
These types of filters are specifically designed to get rid of impurities like dust, sediments, mineral, and chemical contaminants from water supplies employing either a chemical process of filtration or a physical barrier. Often employed in purifying household water, water filters come in a wide array of different shapes and dimensions.
The main requirements for water filters include the particle's size, filter type, filter medium, water flow rate, physical specification, and the planned application. Water filters are present and used in areas like:
- Agricultural irrigation
- Swimming pools
- Water resorts
- Personal and Public aquariums
- Fish ponds
- Refrigerators and water dispensers
- Wastewater companies
Microwave and RF Filters
Designed in the form of a circuit, these devices are designed with the sole purpose of either permitting or blocking certain frequencies. Primarily employed in eradicating certain frequencies and amplify others, these circuits, similar to RF filters that operate at radio frequencies, run on microwave frequencies. They work at a certain frequency range, megahertz, and gigahertz, to be precise.
To clean hydraulic fluids properly, you make use of hydraulic filters fitted inside hydraulic pumps and cylinders. Hydraulic cylinders have filters placed in them to clean the hydraulic oil that lubricates them. Hydraulic fluid filters remove dirt and other solid debris, ensuring that the hydraulic oil flowing in the machine is dirt and contaminant free. Dependent on the fluid to be filtered, engineers build hydraulic fluid filters with different materials to maximize their efficiency while maintaining a high overall lifespan.
We employ fluid filters in cleaning and removing solid debris, sediments, and chemical contaminants from all types of fluids. The filtration process starts when the fluid flows through the filtering elements. The contaminants are kept form flowing through, and the contaminant-free fluid flows out.
There are two parts to a standard fluid filter device. The first part would be the element that holds back the debris, and the second happens to be the filter casing. Fluid filters come in a different size, shape, and material depending on the sort of fluid and the fluid's density.
The main requirement for building a standard fluid filter includes the type, medium, contaminant dimension, fluid flow rate, and the intended application. The materials used in constructing a standard fluid filter include:
- Filtering foam
- Filtering cloth
- Steel (stainless steel)
They convey light having various wavelengths. Placing a plastic material or specific glass plane in the light's path helps achieve this. Different color dyes coat the plastic material or glass plane used. The optical characteristics of these filters depend solely on how they respond to different frequencies that pass through them. These filters are mostly used in photography.
There are two kinds of optical filters, both having unique features – the absorptive filter and dichroic or interference filter.
The main requirements for optical filters include the type of material used, frequency response rate, filter dimension, and wavelength features. Some optical filters only allow a certain range of wavelength pass through them. These include:
- Ultraviolet (UV)
Electromagnetic Interference Filters
EMI stands for electromagnetic interference. These filters also referred to as radio-frequency filters (RFI for short), are electrical circuits that alleviate electromagnetic noise of high frequencies. The noise is usually between 9KHz to 10GHz.
The key requirement when building EMI filters includes voltage, bandwidth, current, and specified frequency.
Primarily used by them between the telecommunication or electronic device and an AC power line, EMI filters design makes it capable of protecting all types of electronic systems.
Smaller models can also go on PCBs, connectors, or stand-alone components for affixing in utility cabinets. There are various types of electromagnetic filters available, and they all possess unique wavelengths. These filters including:
- Low pass
- High pass
- Reject pass