Process and device for coupling drying of high temperature steel slag and sludge

Abstract

The invention relates to a process and device for coupling drying of high temperature steel slag and sludge. The process includes the steps of: 1) slag ball mixing and heat homogenizing: transferringsmelting slag into a slag ball mixer, placing a number of steel balls in the slag ball mixer, fully mixing the smelted slag with rolling steel balls in the slag ball mixer and performing heat exchange, capturing the heat of the slag quickly by the steel balls for cooling, and performing crushing to form grain slag; 2) mixing and drying of slag, balls and sludge: when the smelted slag is cooled bythe steel balls to 200-800DEG C, mixing to-be-dried sludge into the slag continuously to complete homogenizing mixing quickly under the combined action of the rolling steel balls and grain slag, at the same time enabling contact of the sludge with the steel balls and grain slag to let the sludge absorb heat and rise in temperature, and discharging the moisture mainly in the form of steam; and 3) separation of slag, balls and sludge: separating the steel balls, slag and sludge that are mixed together, sending the grain slag and dried sludge into corresponding bins respectively, then conductingtransportation to users for follow-up resource utilization.

Description

technical field [0001] The invention relates to solid waste treatment / sludge drying technology, in particular to a process and device for coupled drying of high-temperature steel slag and sludge. Background technique [0002] With the rapid growth of economic development and urban population, the treatment rate of industrial and urban sewage is continuously increasing, the amount of sludge in sewage treatment plants is increasing day by day, the sludge disposal technology is relatively backward, and the phenomenon of sludge siege is becoming more and more serious. It is a necessary link to realize the harmless, reduction and resource utilization of sludge. The sludge from the sewage treatment plant is mechanically dehydrated, and the moisture content is generally between 75% and 85%. If the moisture content of the sludge is reduced to below 20%, the conventional sludge drying technology usually uses electric heating or The way of steam heating needs to consume a lot of ener...

AI Technical Summary

Problems solved by technology

The sludge from the sewage treatment plant is mechanically dehydrated, and the moisture content is generally between 75% and 85%. If the moisture content of the sludge is reduced to below 20%, the conventional sludge drying technology usually uses electric heating or The steam heating method consumes a lot of energy, resulting in high sludge drying costs

[0003] At the same time, as a big iron and steel country, my country produces nearly 1 billion tons of steel annually, and produces more than 200 million tons of steel slag every year. The heat energy contained in each ton of slag is equivalent to 60 kilograms of standard coal. Since slag is a poor conductor of heat, the waste heat of slag is recovered The progress is slow, and the existing slag treatment adopts the water quenching process, and a huge amount of heat energy is wasted in vain

In order to solve the problem that the high cost of traditional sludge drying affects sludge disposal, and the waste heat of iron and steel slag cannot be effectively utilized, the process route and implementation method of using metallurgical slag waste heat to dry sludge are proposed

[0004] The representative patents of existing sludge drying technology are as follows: Zhejiang University has carried out many beneficial works in the field of sludge drying, which mainly uses waste heat to dry sludge, such as Chinese patent CN200510048978.6 using boiler waste heat, CN200510049554.1 and CN200510049556 .0 use of power plant flue gas waste heat; CN200410052759.0 discloses a return-type temperature-controllable sludge drying device and method, which uses dry sludge with a particle size greater than 4 mm to return and mix with wet sludge, and uses steel wire The net cuts the sludge into smaller pieces and enters the rotary kiln, which can improve the efficiency of the subsequent hot air drying, but it cannot be achieved if the moisture content of the sludge is too high

Chinese patent CN03155966.2 adopts a negative pressure sealing method, which cuts off the channels for the outward transmission and spread of various viruses produced in the sludge treatment process, and also avoids the polluted air and other contamination of the system space during the system’s movement. The virus carried by the system leaks and spreads to the outside world, but since all process devices are concentrated in mobile equipment, its processing capacity must be relatively low, and continuous operation cannot be realized

[0005] Most of the above-mentioned existing sludge drying technologies use hot slag as a heat source, and couple hot slag cooling treatment with sludge drying treatment. The process of sludge drying through slag treatment has not been reported yet.

Images