Water production directly from the well is the best solution to the problem of water supply in a private home. But if it is planned to use the pumped liquid for drinking, then you can’t do without special cleaning. For this, downhole filters in different designs are used. The choice will depend on the characteristics of the water source itself, as well as on the requirements for the composition of the liquid.
What is filtering done for?
There are many threats posed by untreated water from a conventional well. The main dangers include a high concentration of iron, salt, manganese and nitrates. This will be evidenced by an unpleasant odor and a specific taste. The presence of foreign solids is undesirable both for the body and for equipment using water. Therefore, in any case, a well sand filter with rough cleaning should be provided. These are standard membrane devices that can be integrated into the design of pumping equipment. More complex systems should be used if signs of bacteriological infection are detected.
If groundwater at least somehow interacts with the remains of fertilizers and household waste leaving the sewer, then with a high probability there will be lamblia, coliphages, and coliform microorganisms in the well.
Features of a downhole water treatment device
Mandatory cleaning systems include a filter element with filler or replaceable fibers that trap unwanted particles and trace elements. This structural nuance is related to downhole systems with other water treatment facilities. But in terms of technical performance, the very principle of organizing cleaning has significant differences. Firstly, most designs are designed for installation in the circuit between the well itself and the pump. Accordingly, a frame, an installation base and locking regulating equipment are provided.
For the downhole filter, a special loading module is allocated, through which the pumped water passes. Secondly, many devices have sludge traps and other containers for clipping and collecting delayed elements. The most developed designs provide for the possibility of automatic disinfection of the collected material, followed by shipment to the septic tank.
Reverse osmosis filters
This system is by default considered an effective regulator of water for its hardness. That is, the filter corrects oxidation indicators, including due to the output of potassium and magnesium elements. But recently, reverse osmosis membranes have received additional functions, which are expressed in a decrease in iron and a delay in pollution at the molecular level. Well reverse osmosis membrane filters can also remove particles dissolved by ionic and chemical treatment systems. The complexity of the use of equipment of this type lies only in the fact that it requires a separate place for installation. Usually reverse osmosis structures are placed next to the pumps indoors.
Crevice filtering
The system is a single or group installation of several filters in the form of pipes. The design is designed to prevent the passage of coarse-grained elements of 2-10 mm in size. There are precisely slotted and hole models with different configurations of slots and holes on the surface. The device is mounted in the well and serves as a basic barrier in front of mechanical unwanted elements before the water enters the pump. But when choosing a slotted well filter, it must be borne in mind that the desire for deep cleaning at this stage due to narrowing of the holes can result in blockage and rupture of the pipe. Strengthening the structure or using impractical analogs from stainless steel will not lead to anything good either, since in conditions of high well production, productivity will be reduced significantly.
Filters for pumps
Special filters exist for well pumps. In this context, they should be considered as deep. The basis of this filter contains a group of membranes (several degrees of purification) and a sealing element for separating the receiving channel for clean water from the channel directed to the sump. The seal is usually in the form of a bell. It is hinged with a cuff attached to the supporting body.
Since the design of the in-depth filter combines the principles of fine and rough cleaning, special measures are also taken to protect the device from overloads. The simplest method of such protection involves regular automatic cleaning of the downhole filter by washing out accumulated sediment at the outlet. This will require a separate water supply circuit, but again it can be set to work only at certain periods of critical blockage, as evidenced by an increase in pressure in the circuit. Such functionality can easily be implemented on the basis of a modern pumping station.
Casing Filters
Especially under the construction of the well funnel, filter manufacturers produce combined metal-plastic plants with diameters of 100-150 mm. These are perforated casing filters with wire windings and outer casing based on a durable fabric, usually made of fiber-porous polyethylene.
A distinctive characteristic of these devices is the possibility of universal use in alkaline, acidic and neutral soil environments, even with increased salinity. During operation, the well filter for casing made of fibrous-porous polyethylene does not affect the organoleptic quality of the treated water, does not emit chemical elements and is not overgrown with salt substances. For severe operating conditions with high pressure, it is also recommended to use filters with a metal mesh of special weaving. The device protects the water supply circuit from sand inclusions and from small elements with a fraction of 0.1-0.25 mm.
Gravel Strainers
The design of gravel cleaning devices for the well protects the channel from the passage of small rock particles with a diameter of up to 2.5 mm. The frame is made using the same technique as previous devices. Outside, a metal mesh is used for downhole filters, which are twisted with wire and, if necessary, they put on another protective cylinder made of lightweight plastic. A feature of this design is the use of gravel as a natural filler.
In finer cleaning systems, activated carbon and other specialized sorbents have this function, but in this configuration, gravel filler with fine grains of sand is sufficient for surface mechanical cleaning.
Features of titanium filters
As the final stage of mechanical cleaning, manufacturers of downhole filters offer titanium devices. According to the developers, such devices are capable of retaining elements up to 0.8 microns, while softening and deferrizing water. Directly titanium is used as a durable filler, while also providing an antiseptic effect. Although there are mixed opinions about the safety of this material as such, there are practically no complaints about its work and harmful effects. But the strength qualities of well filters of this type, their functionality and ergonomic use are noted.
Reviews of manufacturers of filtration systems
The development and production of downhole equipment and filters are mainly carried out by industrial enterprises. Users of these products especially highlight models from Samara-Aviagaz, Fibos and Spetsmash. As for the Samara-Aviagaz enterprise, its assortment includes inexpensive, but reliable FS well casing filters for casing, which prevent sand drift. According to users, such structures also perform a structural and protective function, preventing collapse of the rock.
The company "Fibos" focuses on fine filters. Owners of strainers of this brand also indicate a positive effect of water softening, and a thin membrane filtration retains particles up to 1 micron.
Spetsmash products are recommended for industrial water treatment . Frameless slotted design is designed to integrate into the wells of any configuration, which expands the scope of such filters. But the cost of this product is considerable, due to the possibility of individual development of the project.
How to make a well filter do it yourself?
The simplest way to make filtration is to use for this purpose a finished perforated pipe like a slotted plastic membrane. Its channel with holes on the surfaces will make screening of large particles, which will be delayed and sent to the sump. This will allow for coarse pre-cleaning before the finer stages of filtration. Both metal and plastic pipes will do. The main thing is to ensure proper perforation. For this, holes with a diameter of 10-15 mm are formed. Their total surface area should be about 15% of the total product area.
Next, the segment must be wrapped in a membrane sheet. Usually, a plastic mesh with cells of the order of 5 mm is used for such purposes. Next, the downhole filter pipe is introduced into the water intake infrastructure at the primary level. It can be fixed with special holders from the casing and, if necessary, bring the elements of the locking regulation.
Conclusion
A filtration system for water from a well is one of the basic conditions for equipping a water supply facility. The requirements for cleaning the liquid increase if it is planned to use it for domestic needs, but technical requirements impose serious requirements on the composition of water. At a minimum, in this case, a filter should be used for the downhole pump, which will protect the equipment from clogging with sand and sludge. If it comes to supplying a private house with a full consumer spectrum, then it is advisable to organize multi-stage water treatment with separate stages of mechanical and biological treatment. The process chain will run from the well itself to the pump and water intake equipment.