DE2749886A1 - Salt load disposal in flue gas desulphurisation plant - by spraying saturated wash water upstream of electrofilter - Google Patents

Abstract

A scrubbing plant is used to remove the sulphur from the flue gases of power stations and refuse incinerators. To prevent an excessive accumulation of salts such as calcium chloride in the wash water, it has to be treated to remove the salt load. This is done by spraying the wash water into the flue gases before they enter the electrofilter at 180-220 degrees C. The water evaporates and the salts become agglomerated with the dust. This improves the conductivity of the dust and raises the filter efficiency.

Description

Description and explanation of the patent application

'' Procedure for discharging the salt load for flue gas washing systems, preferably in desulphurisation plants of power plants and waste incineration disposal plants, from the washing liquid flow '.

It is known that especially when using coal with high Calcium chloride usually increases the salt content of the washing liquid up to 30% and thus inevitably draining the washing liquid from the circuit is necessary in order to avoid over-salting of the washing liquid circuit.

The washing liquid to be drained off must either go through a spray dryer can be modified to precipitate the salt load to bring the water back into the cycle to be supplied or discharged into the receiving water.

Another possibility is to dilute the wastewater accordingly, to then give it to the receiving water.

Both of the necessary process steps are very costly for the procedure.

For this reason, a method is proposed according to the invention for discharging the salt load from the wascnkrelslauf with flue gas scrubbing, preferably behind power plants, to be designed as follows The flue gas occurs at around 180 - 2200C into the electrostatic precipitator to be dedusted.

Behind the electrostatic precipitator, this is reduced to around 150 mg / Nm3 dust content cleaned flue gas fed to the wet flue gas desulphurisation system.

According to the invention, the required liquid with the appropriate Salt load sprayed in front of the electrostatic precipitator, the water evaporates and the salt content agglomerated with the dust, which inevitably leads to an improvement in conductivity the dust to be separated is achieved, so that the efficiency of the electric filter improves and at the same time the problem of salt cargo discharge through them measure according to the invention is solved.

Of course, the invention is not limited to the above in detail The forms of training described are limited, but there are numerous changes possible, but without deviating from the round cross-section, in the case of a flue gas water the excess salt load from the scrubbing liquid circuit into the hot gas area to be injected in front of the electrostatic precipitator, the water to evaporate and the salt load inevitably to achieve agglomeration of the dust and separation in a separator.

Claim

Claims (1)

Method for the discharge of the salt load from the Washing cycle in flue gas washers, characterized in that the desired Washing liquid with the corresponding salt load in the hot gas flow in front of the solid gas burner, preferably electrostatic precipitator, is sprayed.