Descaling agent for calcium-process desulfurization tower and application thereof

Abstract

The invention relates to a descaling agent for a calcium-process desulfurization tower and application thereof, belonging to the technical field of chemical cleaning. The descaling agent comprises, byvolume, 40-60% of organic acid, 10%-15% of inorganic acid, 5%-10% of a cosolvent, 1%-3% of a penetrant and 0.5%-1.5% of a surfactant, with the balance being water. After uniform mixing of the above components under stirring, the pH value of the descaling agent is controlled to be less than 0.5. A cleaning solution with a concentration of 10 to 30% is prepared from the descaling agent at first andthen is introduced into the desulfurization tower through a cleaning pipeline for spraying; and pipeline pressure is controlled to be 1.0 to 2.0 MPa, a flow velocity is controlled to be 10 to 20 m<3> / h, and the cleaning solution is used for continuously and cyclically flushing the interior of the desulfurization tower for 2 to 6 hours. The descaling agent can achieve high-efficiency and thoroughcleaning of stubborn scales on the surface of the internal structural components of the desulfurization tower; 2 to 6 hours is needed for cleaning once, and more than 96% of the scales can be removedafter cleaning; operation is simple and easily controllable; the normal operation of a desulfurization system can be ensured; the utilization rate of desulfurization equipment can be improved; the operation cost of the equipment can be lowered; and the purposes of energy conservation and emission reduction are achieved.

Description

technical field [0001] The invention relates to a descaling agent for a calcium desulfurization tower and its application, belonging to the technical field of chemical cleaning. Background technique [0002] The calcium method desulfurization tower is a device that uses lime-limestone as the calcium method desulfurization agent to remove low-concentration sulfur dioxide electrolytic aluminum flue gas. Calcium ions (Ca 2+ ) slurry is also a special defluorination agent (the defluorination efficiency is over 95%). In addition to desulfurization and defluorination, the calcium wet desulfurization tower also has the ability to remove nitrogen (nitrite), chloride, carbon dioxide, dust and fly ash , organic acids and trace heavy metals and other pollutants, so that the technical indicators of desulfurization flue gas fully meet the latest national environmental protection standards. During the operation of the calcium desulfurization tower, the desulfurizer lime slurry is recycl...

AI Technical Summary

Problems solved by technology

Lime slurry reacts with flue gas in the tower to generate low-soluble calcium sulfite, calcium sulfate, calcium carbonate, calcium fluoride and other substances, which will cause fouling of components such as demisters, packed towers, and spray devices in the tower , if not cleaned in time, fouling will lead to a decrease in flue gas treatment capacity, a decrease in flue gas purification rate, a decrease in equipment operating efficiency, an increase in material consumption, energy consumption, and an increase in equipment operating costs. In severe cases, the desulfurization tower will be forced to stop operating , causing economic losses; therefore, in order to ensure the stable and efficient operation of the desulfurization tower system, it is necessary to use a chemical cleaning agent with strong scale dissolving ability to regularly clean the fouled internal components and the scale of the pipeline

[0003] The traditional chemical cleaning technology is strong acid cleaning or strong alkali cleaning, mainly using hydrofluoric acid and strong alkali, which have a great impact on human body, equipment and environment