Heat exchange method for printing and dyeing sewage

Abstract

The invention relates to a heat exchange method for printing and dyeing sewage, belonging to recycling of heat in the printing and dyeing sewage. Alkaline colorless sewage produced in pretreatment and colored sewage produced in dyeing, printing and washing separately flow into water collection tanks according to different properties of sewage produced in each procedure during dyeing and printing production, and two box type heat exchangers are respectively adopted; the alkaline colorless sewage produced in the pretreatment flows into a boiler desulfurization device after exchanger and cooling, the sewage produced in neutralization flows into a sewage treatment tank again until the flue gas emissions meet the standards, no acid needs to be added for neutralization of alkaline for sewage treatment, and thus three purposes can be achieved; and the colored hot sewage produced in the dyeing, printing and washing flow into the sewage tank after exchange and is decolorized and then subject to biochemical treatment to ensure that the sewage discharging meets the standards. Clean hot water produced after exchange can be supplied for production of each machine, the temperature of the supplied water for production can be increased, the steam consumption can be reduced relatively, and thus the purposes of energy conservation and emission reduction can be achieved.

Description

technical field [0001] The technology of the invention belongs to the recovery and utilization of heat energy contained in printing and dyeing sewage. Background technique [0002] Printing and dyeing enterprises use steam to heat water for washing all the time in production, thus generating a large amount of sewage containing heat energy every day, which is wasteful and increases the difficulty of sewage treatment. Printing and dyeing practitioners in various countries have been trying to recycle this kind of heat-containing sewage, and related machinery and equipment industries have also participated in and provided some heat exchangers. We have also purchased a few for use, but it is not ideal. The exchange rate is not high, cleaning disadvantages such as difficulty and high cost. Contents of the invention [0003] In order to solve the technical problem that a large amount of heat energy contained in sewage is wasted during the printing and dyeing process, the inventi...

AI Technical Summary

Problems solved by technology

[0004] 1. The convection design is adopted to make the clean water and sewage flow in the opposite direction, the sewage goes through the tank, and the clean water goes through the pipes. The pipes are connected by flanges, which is convenient for cleaning and maintenance, and solves the problem that other heat exchanger pipes are easy to block and difficult to dredge.