CS263143B1 - How to edit vo.ly - Google Patents

Abstract

A method of treating water, especially circulating water of cooling circuits, by chlorination, wherein used washing solutions obtained during the purification of chlorine-containing exhaust gases, which have chlorine concentrations of 22 to 47,000 mg.l-1, preferably 130 to 9,300 mg.l-1, are introduced into the treated water.

Description

The invention relates to the chlorination of water, in particular the cooling circuit water, to suppress biological recovery.

The circulating water of technical cooling circuits is normally chemically treated so that the cooling efficiency is not impaired by the biological growth of the heat exchange surfaces. The most common means of this treatment is chlorine and its solutions. The best effects with the lowest chlorine consumption are achieved with periodic shock dosing when a short-term higher concentration paralyzes the natural recovery of the water more profoundly than sustaining a constant concentration at the necessary level, which is more expensive.

The chlorination process, already supplied directly to the process as a pyrazole or in the form of a compound whose decomposition is only provided by chlorine (e.g., thermal destruction of tetrachloromethane), often produces off-gases in which chlorine is a component to be removed and disposed of.

Sewing is most often the washing of off-gases with a suitable solution or water. The occurrence of off-gases is often batch-like.

According to the invention, the method of treating water - in particular the circulating water of cooling circuits - by chlorination consists in introducing into the treated water used washing solutions with a chlorine concentration of 22 to 47 000 mg.l ^-1 , preferably 130 to 9 500 mg.l ^-1 , obtained from the purification of chlorine-containing off-gases.

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The process according to the invention makes use of a partial combination of the above processes and, on the one hand, eliminates the need to dispose of a chlorine-saturated scrubbing solution and, secondly, replaces it by introducing it into the cooling circuit water. i completely eliminates the dosing of chlorine or hypochlorite into the circuit water.

Example

The effluent from the chlorine recovery of the isomerization catalyst, obtained by thermal destruction of the organic polychlorinated compound, contains from each of the batches to be treated an excess of free chlorine which is washed out of the off-gases to prevent leakage into the atmosphere. The washing solution obtained is not disposed of, but according to the invention it is newly used for the treatment of the orbital cooling water into which it is introduced. the hypochlorite necessary to treat the water in order to protect the circuit equipment from biological overgrowth. A side benefit is to reduce the amount of wastewater by the entire volume of the scrubbing solution and to reduce the salinity of the wastewater by the entire amount of salts resulting from the neutralization of the scrubbing solution and the chlorine contained therein.

Technical data:

in * - ~ | chlorine in scrubbing solution 21%. 4,950 mg.l chlorine trap 69 to 81 kg per batch annual hypochlorite solution savings of 36.1 t ·

Claims (1)

Process for the treatment of water, in particular the circulating water of cooling circuits by chlorination, characterized in that the scrubbing solutions obtained for the purification of chlorine-containing off-gases with a chlorine concentration of 22 to 47 000 mg.l ^-1 , preferably 130 to 9 500 mg, are introduced into the treated water. l \