Water supply is negotiable - definition, scheme and features. Recycling water supply system

Due to its unique properties and cheapness, water is widely used in industry as a working body. Its processing after use (cleaning, cooling) makes it possible to create a circulating water supply with repeated use. Due to this, water consumption is significantly reduced, as well as environmental pollution is prevented. As a result, comfortable conditions for people's living are created.

Operating principle

The water supply system must be constantly replenished and periodically updated. Water is mainly used as a coolant or coolant. In each case, it is pre-cooled or heated. Before re-use, water can be purified, as it is contaminated with products of technological processes.

The share of circulating water supply increases in all branches of industry. The liquid is most often used in heat exchange equipment. Water is repeatedly subjected to heating and cooling in spray tanks or cooling towers. Its most part is lost in the process of evaporation.

Turnover water supply of the chemical production enterprise is already 98%. There it is used in technological operations, where it is required to purify water from industrial waste.

Separation of slurry from water makes it possible to process it and extract valuable components.

Water flow rate

Everywhere water is used for cooling mechanisms and machines in production processes. For processing 1 m ^{3 of} oil it is required in 2.5 m ³ . For a refinery, the daily demand for water is enormous and the discharge into the sewer system is unacceptable here. Therefore, it passes through treatment facilities and is reused. The water supply for the CHP works according to the principle of steam generation, its supply to the turbines and condensation in the cooling towers, after which the water is returned to work.

In life many of these technologies are not of interest. But the owners of small enterprises constantly face the need to use recycled water in car washes, in swimming pools, in laundries, etc.

Schemes of water use

Two schemes of operation of circulating water are applied:

• Without treatment after use;
• With intermediate processing.

In the first case, water can be used after the technological process, when it maintains acceptable indicators. For example, containers can be washed with drinking water, after which it can be used for other household needs in the subsidiary farm, and surpluses are discharged into the sewerage system. For industrial enterprises such a scheme is usually unacceptable.

Water supply scheme of the enterprise

Water cycle should meet certain requirements:

• Absence of negative influence on product quality;
• Should not form deposits of salts in the system;
• Low corrosive effect on equipment;
• Absence of biological fouling system.

The industrial system of recycled water supply collects and stores most of the impurities in the receiving waste water tanks and in the cooling tower tanks.

The tanks are cleaned periodically by hand or by mechanization of the sludge removal process without stopping the system.

Treatment of water

When evaporating in recycled water, calcium salts accumulate, which are deposited in pipes and heat exchangers. They also drop out as a result of heating the water, when the solubility of the gases decreases and the hydrocarbonate ions decompose, forming an insoluble precipitate.

Carbonate deposits are prevented by acidification, phosphatization, recarbonisation and softening of water. Acidification is a common way, due to low costs and ease of implementation. It is important to observe the dosage of acid to prevent corrosion of the equipment.

Recarbonization of water is carried out by treatment with carbon dioxide. For this purpose, flue gases that have been removed from the ash are used, which are mixed with water using ejectors or bubbling tubes laid on the bottom of the tank.

Phosphatization of water requires a small consumption of reagents (1.5-2.5 g / m ³ ), but the costs are still large. Advantage of the method is the absence of aggressive properties of the solution.

If there is sufficient oxygen and organic substances in the return water, the equipment can become overgrown. This leads to a deterioration in heat transfer and an increase in hydraulic resistance in pipelines. To combat fouling, chlorination of water and the addition of copper sulfate are used.

Which systems are better?

The use of circulating water supply systems is associated with significant costs for their creation and operation. At chemical plants, production products contaminate recycled water. A centralized system takes up large volumes, where complete replacement or high-quality purging is sometimes impossible.

Effective operation of circulating systems is achieved by combining closely located consumers with similar modes of operation in groups with low-capacity water coolers. Local systems provide an optimal mode of operation for each consumer.

Water supply system for car wash

Water recycling for car washes and other small businesses is being developed with the complete elimination of the possibility of discharging sewage into the sewerage system. Water does not change its quality and can be used in a closed system.

Advantages of local treatment facilities :

• Reduction of water consumption to 90% with replenishment of water losses;
• No contamination by sewage;
• Environmental friendliness.

In all systems, settling and filtration are used as the main cleaning methods. The installation of circulating water supply AROS and similar to it is widespread.

Sinks containing oil, dirt and fuel enter the sump and pass through 3 cleaning sections with upper and lower overflow.

The sump is not included in the installation of the unit. The water recycling system contains it as a basis. It is designed and manufactured in accordance with the recommendations of the manufacturer of cleaning stations. For washing with one post, the volume of the clarifier is 6 m ³ .

The spilled water is supplied by a submersible pump from the last section to the sand and gravel filter for cleaning of the remaining impurities and then to the storage tank. The unit can be equipped with a filter column with a sorbent to remove oil products.

The system provides automatic feeding of a solution of hydrogen peroxide or other sterilizing means by the dosing pump, which ensures the destruction of microbes and unpleasant odors. For this, ultraviolet lamps installed above the sediment bowl can also be used.

From the storage tank, water is recycled by passing through a fine filter cartridge. The level of the liquid in the tank is controlled automatically.

The station of recycled water supply "Scat" operates in the same way. It is available in the floor or in the underground version. Variants of layouts provide for deep cleaning of drains or without it. The facilities detain mechanics, oils, oil products and organic impurities.

Equipment of compact treatment facilities

Turn-key water supply for small-scale industrial enterprises includes the following equipment.

1. The submersible pump is suspended on the cable in the final section of the settler. Connection with the pipeline is carried out with the help of adapters and a flexible hose. The control is made from the control cabinet. A float sensor for dry running is provided.
2. The pressure boost module includes a pump, a manometer and a buffer tank. It allows you to maintain a constant pressure of water supplied to the sink.
3. The filter column is a cylindrical tank with a filler, an air vent and a backwash switch.
4. Purified water is collected in a storage tank. From above, sterilizing reagent is introduced into it. The water level is monitored by sensors.
5. Automatic control of pumps is made by electronic system. On the front panel of the control cabinet are indicators and switches, through which the operator sets the operating modes of the system and monitors its operation.

Revolving industrial water supply systems for cleaning road and rail transport can provide deep treatment of effluents with their discharge into the sewage system.

Conclusion

Water supply is created for the purpose of environmental protection of the environment, economy, as well as in case of emergency, caused by the creation of a small enterprise. The profitability is determined by project calculations. In the future, it will only increase in connection with the increase in the cost of water and the growth of fines for environmental pollution.