System for drying sludge by utilizing radiation heat of rotary cement kiln

Abstract

The invention discloses a system for drying sludge by utilizing radiation heat of a rotary cement kiln, comprising a sludge feeder, a first scraper conveyor, a second scraper conveyor, a rotary cementkiln, a first closed box, a second closed box, a first closed box feed port, a second closed box feed port, a first tracked conveyor, a second tracked conveyor, a fixed rolling toothed harrow, a first closed box discharge port, a second closed box discharge port, a first ventilation opening, a second ventilation opening, a first ventilation pipe, a second ventilation pipe, a discharge conveyor, afirst transmission device, a second transmission device, an exhaust fan, a biological filter and the like. The system for drying sludge by utilizing radiation heat of a rotary cement kiln can dry sludge under the condition of low temperature by utilizing the radiation heat of the rotary cement kiln, thereby keeping the original calorific value of the sludge; and the dried sludge is used as the auxiliary material of cement, and can contribute calorific value during cement burning, so that not only the sludge in urban sewage treatment factories and river and lake dredging sludge can be thoroughly treated, but also the heat energy resource of the sludge can be largely utilized.

Description

technical field [0001] The invention relates to a sludge drying system utilizing the radiant heat of a rotary kiln in a cement plant. Background technique [0002] According to the "Eleventh Five-Year Plan" of the national environmental protection and the "Eleventh Five-Year Plan" for the construction of urban sewage treatment and recycling facilities nationwide, all cities in my country must build sewage treatment facilities by 2010, and the urban sewage treatment rate should not be lower than 70%. It is estimated that the national urban sewage treatment capacity will exceed 100 million tons per day, and at the same time, it can be expected that the accompanying sludge (with a moisture content of about 80%) will be as high as 30 million tons per year, plus the dredging sludge of polluted rivers and lakes and urban sewer sludge etc., the amount of municipal sludge produced every year is not only very large, but also increases at a growth rate of 10-15% every year. How to disp...

AI Technical Summary

Problems solved by technology

[0004] In the past few decades, my country has made breakthroughs in water treatment technology through the introduction, digestion and absorption of foreign advanced technologies in terms of urban sewage treatment. However, as an organic part of urban sewage treatment systems, sludge However, the development of advanced treatment and disposal technology is slow, which restricts the process of urban sewage treatment to a certain extent. This is related to the fact that the existing international sludge treatment and disposal technology is not suitable for China's national conditions.

The sludge treatment and disposal methods established in long-term practice in foreign countries mainly include sanitary landfill, incineration and land utilization. There are three prerequisites for the implementation of these methods: first, there must be enough sludge landfill space; Bear expensive equipment investment and high operating costs; third, there are strict restrictions on the content of harmful substances such as heavy metals in sludge

In addition to being unable to afford too high sludge treatment costs economically, my country's urban sludge has two obvious characteristics different from foreign countries. One is that the amount and volume of sludge are particularly large, and the main Concentrated around the city, there is no space suitable for sludge landfill; second, due to the combined treatment of domestic sewage and industrial wastewater, the composition of the sludge is very complex, especially the heavy metal content is high, and the land use of the sludge is limited.

Therefore, foreign sludge treatment methods cannot be used for reference by our country

At present, most of the sludge from urban sewage treatment plants and dredging sludge from rivers and lakes in my country are temporarily stockpiled or simply landfilled in disorder after preliminary treatment, which not only costs a lot of money and occupies a lot of land resources, but also destroys The ecological environment has a serious impact on human health

In particular, the infiltration of sewage in the sludge will cause incalculable damage to groundwater resources. In fact, there is no space and place suitable for storing this kind of sludge around the city. The environment caused by the temporary landfill of sludge The harm of secondary pollution actually offsets the environmental benefits of sewage treatment and river dredging

Images