What are the purifying water filters

The liquid flowing in a centralized water supply system can only very conditionally be considered suitable for use for technical purposes - for washing, washing dishes, etc. With a very big stretch, it can be used for cooking, but you cannot drink it without boiling at all. To bring it to the norm, it is necessary to use different types of filters for water purification. There are inexpensive installations, but they, as a rule, have low productivity and average cleaning quality, and there are expensive systems that can give ideal results.

To bring up to normal, different types of filters are needed for water purification

The situation with water supply from a well or well is no better. There is still a high probability of bacterial contamination, so the cleansing should be even better. In general, it is necessary to take the sample for analysis, and then, based on the results, select the required types of filters for water purification. In private homes, this is usually a multi-stage system that results in drinking water quality.

Purification from mechanical impurities

The water that flows in our water supply contains grains of sand, fragments of rust, metal, winding, etc. These impurities are called mechanical. Their presence has a bad effect on the durability of valves (taps, valves, etc.) and household appliances. Therefore, in apartments and in private houses, filters are installed at the inlet to remove them. There are few types of filters for water purification from mechanical impurities. It is with mesh and discs as filter elements.

The most common filter for removing mechanical impurities in water

The filter element in mechanical filters is a mesh. According to their cell sizes, these filters are divided into coarse (300–500 µm) and fine (larger than 100 µm) devices. They can stand in a cascade - first coarse cleaning (sump), then fine. Often, a coarse filter is placed at the inlet to the pipeline, and devices with a smaller cell are placed in front of a household device, since different equipment may require different degrees of water purification.

According to the orientation of the flask in which the filter element is installed, they are straight and oblique. Oblique ones create less hydraulic resistance, therefore they are most often installed. When installing, the direction of flow must be observed, it is indicated by an arrow on the body.

Mechanical filter

There are two types of mechanical filters - with and without auto rinse. Devices without auto-flushing are small in size, their inlet / outlet diameters are selected according to the size of the pipe in which they are installed. Body material - stainless steel or brass, threaded connections are different (external or internal thread is selected as needed). The cost of this type of mechanical filters is low - in the region of hundreds of rubles, although branded ones can cost much more.

Mechanical filters without backwash: straight and oblique

Since the grids are clogged and need to be cleaned periodically, the bottom of the flask is removable. If necessary, unscrew it, take out and wash the mesh, then put everything back (all work is carried out by first shutting off the water).

Mesh with auto wash

A mechanical filter with auto-flushing (self-flushing) has a branch pipe and a tap at the bottom of the flask with a filter element. The branch pipe is discharged into the sewer using a hose or a piece of pipe. If it is necessary to rinse such a filter, simply turn on the tap. Water under pressure flushes the contents into the sewer, the tap closes, you can continue to operate.

Types of mechanical flushing water filters

This type of mechanical water filter often contains a pressure gauge. It determines whether the net is clogged or not. The pressure has dropped - it's time to clean the filter. If the flask of the device is transparent, there may not be a pressure gauge - you can determine by the appearance of the grid or the walls of the flask. In this segment, oblique water filters are rare, but they are still available.

A pressure reducing valve can be integrated into the housing to neutralize pressure differences. There are models with the ability to install an auto-wash unit.

Installation example of a mechanical filter with auto-cleaning

The piping of this type of mechanical filter is a little more complicated - an outlet to the sewer is required, but there are also models with different types of threads so that as few adapters as possible can be used.

Connection types

Mechanical purification filters can be clutch or flanged. Flanged - this is usually the main equipment for water pipelines with large pressures and diameters. Can be used for water supply in a private house.

Flanged strainers

Disc (ring) filters

This type of equipment is less common, although it is less prone to silting, it has a large filtration area, and can retain particles of different sizes.

The filtering element is a set of polymer disks, on the surface of which there are depressions-scratches of different depths. The disks in the assembled state are tightly pressed against each other, the water passes through the hollows in the disks, while particles of a larger diameter settle on them. The movement of water is spiral, so that suspended solids are removed efficiently.

Disc filter for water

When the water filter becomes clogged, the discs are removed from the housing, pushed apart and washed. After that, they put it in place. The discs must be replaced periodically, the service life of the filter element depends on the amount of contamination and the quality of the discs themselves. There are models with auto wash.

They are mounted in a burst pipe, the bulb can be directed up or down (see the installation instructions).

Inexpensive types of filters for purifying water before drinking

Water purified from mechanical impurities can be used for domestic needs, served in household appliances, but it is suitable for drinking or cooking only conditionally - after boiling. To be able to drink it without boiling, fine filters are needed, which retain a significant part of the substances dissolved in water and disinfect it. Consider how to make drinking tap water, types of filters for water purification that can be used.

It is unlikely that what flows from the tap can be called drinking water

Filter jug

The easiest, but not very productive, way to make tap water drinkable is to run it through a filter jug. Purification takes place in a replaceable cartridge through which water passes. A good cartridge contains the following filter media:

• polypropylene fibers for sedimentation of mechanical impurities residues;
• activated carbon with additives to remove microorganisms, chlorine compounds;
• ion exchange resin for removing manganese and calcium salts, radionuclides, iron compounds, heavy metals;
• porous activated carbon for water clarification, organic deposition.

Jug filter - simple, cheap

Filter jugs differ in the composition of the cartridge, its resource (how much water can be purified) and in volume. The smallest models of benchtop filters can clean 1.5-1.6 liters of water at a time, the largest - about 4 liters.Just keep in mind that the column "filter volume" indicates the volume of the bowl, the useful volume (the amount of purified water) is much less - about two times.

Filter nozzle for tap

A very compact filter for running tap water that fits on the tap. Cleansing speed - from 200 ml / min to 6 l / min. The degree of purification depends on the composition of the filtering part, but usually does not differ much from filter jugs.

According to the method of operation, there are two types of filters on the tap - some are put on immediately before using it, others have the ability to switch to the "no cleaning" mode. It is more convenient, of course, the second option, but switches often break. As a temporary measure - an excellent solution, but "permanently" it is better to choose another device.

Under / on sink filters - a way to get a large amount of drinking water

For greater productivity and better water purification, filters are used that are installed under or on the sink, they can also be mounted on the wall.

There are two types of such systems - cartridge and reverse osmosis systems. Cartridge ones are cheaper, and this is their plus, and the minus is that it is necessary to monitor the condition of the filter element and change it in time, otherwise all the accumulated dirt passes into the water.

Tap nozzles for water purification

Reverse osmosis systems are already more technological equipment that has a much higher cost, but the quality of cleaning and productivity are much higher. These water treatment plants use a multi-layer membrane, each layer of which traps certain types of contaminants.

Cartridge

In cartridge filters, the cleaning quality depends on the number of cleaning stages - individual filter elements that “trap” a certain type of contamination.There are single-stage systems, there are two, three and even four-stage filters.

In single-stage, universal inserts with a multilayer structure are used. They are inexpensive, but it is difficult to predict whether you will be satisfied with the degree of cleaning. The composition of water in different regions is very different and it would be desirable to select / replace filters as needed. And so, we have to hope for the versatility of the liner.

Water cartridge filter device

In multi-stage cartridge filters, the housing consists of several flasks, each of which has a separate / special filter element that removes certain contaminants. The flasks are connected in series by means of overflows, flowing from one flask to another, water is purified. In this case, it is possible to select the types of filters for water purification specifically for your analysis, which will undoubtedly improve the quality of cleaning.

Benchtop cartridge filters for running water

The most inexpensive version of cartridge filters is installed next to the sink. These are miniature models that are small in size. They can be one or two stage, there is a small valve on the body. The filter is connected with hoses to a special outlet of the mixer, it can be connected directly to the water supply.

The desktop version can be connected to a tap or water supply

Trunk

These are usually cartridge single-stage filter flasks that are placed after the mechanical filter. They remove a significant amount of impurities, making the water drinkable and protecting household appliances from the formation of scale and other deposits. Their disadvantage is the need to change the filter elements.

Filter flasks are also called trunk filters

The flask is made transparent for easy monitoring of the state and degree of contamination. If there is visible contamination, replace the cartridge with another. In some models, it is possible to independently restore the performance of the cleaning element - it is washed under running water. In other models, this is prohibited, so read the instructions carefully.

Multi-stage filters

They differ from those described above by a large number of flasks-cases, each of which has a cartridge that removes various types of contaminants. The more stages of cleaning, the cleaner the water is obtained. It is necessary to select the composition of the filter elements for the specific composition of the water (carefully read the technical characteristics and description).

Multi-stage water treatment systems give good results

These installations can also be installed on the mains, or they can be put under the sink and receive high quality drinking water.

Reverse osmosis

The most advanced water purification technology today is reverse osmosis. Here, multilayer membranes are used that allow only water and oxygen molecules to pass through, not allowing even the smallest contaminants to pass through.Water is obtained practically without salt content, which is also not good. This is precisely the disadvantage of reverse osmosis systems. To neutralize it, the installations are retrofitted with mineralizers, which add the necessary minerals.

The disadvantages of this system include their low productivity - only one glass or so of pure water can run into a minute. It is clear that such a speed is inconvenient, so that it is felt less, manufacturers complete the installations with tanks for purified water, to which the taps are already connected.

Reverse osmosis systems are equipped with purified water tanks

Filters for water purification from solutes

In addition to mechanical impurities in tap water there is also a decent part of the periodic table: iron, mercury, manganese, potassium, calcium (hardness salts from which scale is formed), etc. All of them can be removed, but different filters are required for this.

to make the water drinkable, different types of filters are used to purify water

To remove iron

Most often, there is a large amount of iron in water from wells or wells. It gives the water a reddish tint and a specific taste, is deposited on the walls of plumbing fixtures, clogs shut-off valves, therefore it is advisable to remove it. It makes sense to do this if the amount of iron exceeds 2 mg / l.

Ferrous iron dissolved in water can be removed from the water using a catalytic filter. This is a large cylinder, into which catalysts are poured, the work is controlled by a small processor, that is, this equipment requires a power supply.

Catalytic filters are used to remove iron from water

The backfill in the catalytic filter accelerates the oxidation of ferrous iron and its precipitation many times over. Depending on the backfill, impurities of manganese, chlorine, and other substances dissolved in water can also be removed; also, during the cleaning process, mechanical particles settle to the bottom. The accumulated deposits are removed according to a set schedule, usually at night. The backfill is washed under the pressure of water, everything is drained into the sewer, during the flushing, the water supply is stopped. Catalytic filters are complex and expensive equipment, but they are the most durable available.

How the aeration filter works

Another way to remove iron and water is aeration. Air is supplied to a cylinder with an injected pump in the form of a fine suspension of water (through nozzles). The iron in it reacts with atmospheric oxygen and its oxides are filtered out at the outlet. There are two types of filters for water purification of this type - pressure and non-pressure. For more active oxidation, these units can be supplied with an oxidizing agent - hydrogen peroxide or sodium hypochlorite. In this case, biological water purification is also carried out - from microbes and bacteria.

More about for purification of water from a well and a well, read here.

Water purification from hardness salts

To soften water, filters with ion exchange resins are used.In the process of interacting with water, harmful impurities are replaced with neutral or useful ones (an increase in the amount of iodine and fluorine).

Outwardly, this equipment is a tank partially filled with ion-exchange material. It is paired with a second similar regenerator tank filled with a highly concentrated salt solution (a special one is sold in tablets, highly purified).

Ion exchange resins are excellent at removing hardness salts

The advantages of filters for water purification of this type are high performance, low noise level during operation, rare replacement of the filling (it lasts for 5-7 years). Ion exchange filters are the best choice for water softening. Cons - in the need to use a regeneration tank with concentrated brine. To get potable water, you need to install an activated carbon filter.

This is how they look