CN202322657U - System for firing ceramsite by using sludge - Google Patents

Abstract

The utility model provides a system for firing ceramsite by using sludge. The system comprises a dehydration unit, a mixed granulation unit, a rotary kiln and a ceramsite storage bin. Firing of the sludge ceramsite is finished by controlling the parameters of the rotary kiln; the sludge is not required to be dried before granulation, and the sludge of which water content is reduced to about 50 percent by adopting geotechnical tube bags or other modes is mixed with clay in a proper ratio and then directly extruded and granulated, so that the consumption of energy is reduced; and the rotary kiln is high in treatment capacity and efficiency, and can effectively realize recycle of the sludge.

Description

A system for firing ceramsite from sludge

technical field

The invention belongs to the technical field of sludge treatment, and in particular relates to a system for firing ceramsite with sludge dehydrated by geotechnical tube bags.

Background technique

With the rapid development of my country's economy and the emphasis on environmental protection, urban domestic sewage and industrial wastewater must be treated to meet national standards before they can be discharged. During this process, most of the pollutants in the sewage are transferred to the sludge, and urban sewage Mud is a kind of extremely harmful solid waste, which contains pathogenic microorganisms, organic and inorganic pollutants and heavy metals. At present, the amount of urban sludge plus polluted river and lake dredging sludge in my country is very large and continues to grow. Thorough treatment of sludge and prevention of its secondary pollution are common problems faced by the world, and it is urgent to solve this problem.

Through the analysis of the main chemical components of urban sludge and river dredging sludge in China, it is found that the content of SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , CaO, and MgO contained in it is similar to that of clay, and its proportion meets the requirements of burning. Requirements for making ceramsite. If sludge is used to burn ceramsite, not only can fully utilize part of the organic matter in the bottom mud as the foaming material in the ceramsite roasting process, but also the inorganic components in the bottom mud can be used. High temperature roasting can Completely kill pathogens, and consolidate heavy metals in ceramsite, eliminating the pollution of heavy metals.

Ceramsite is a new type of concrete aggregate that meets the needs of modern buildings with light weight and high performance. It can replace heavy sand and gravel and become an ingredient in the production of lightweight building materials and lightweight concrete, which can greatly reduce costs. In addition, pollution Clay ceramsite has the characteristics of rough surface, large specific area and high porosity. It has strong advantages and development potential when used as water treatment filter material ceramsite.

Contents of the invention

The invention provides a system for firing ceramsite from the bottom mud of a heavy metal polluted lake reservoir, the system includes:

(1) Sludge dehydration unit

Use geotechnical tube bags to dehydrate urban sludge or dredged sediment from rivers, lakes and reservoirs. Add flocculant before filling the sludge into geotechnical tube bags. After filling the geotechnical tube bags, they will be solidified and dried for 10 to 60 days. When it is 45% to 55%, break the bag to take out the sludge. It can also be dehydrated by other methods such as natural drying until the moisture content is 45% to 55%.

(2) Mixing and granulation unit

Mix the sludge and clay raw materials with a moisture content of about 50% in the mixer at a ratio of 1:1 by volume. This ratio is conducive to the formation of high-quality ceramsite with low bulk density and high specific surface area. Extrusion granulation process, the moisture of the billet comes from the semi-dry bottom mud, no need to add water.

(3) Sludge ceramsite rotary kiln

The formed sludge particles are sent to the ceramsite rotary kiln through the belt conveyor, and the ceramsite completes the drying, preheating and roasting process in the rotary kiln. Rotation per minute, the temperature distribution in the kiln is 180°C to 320°C in the drying zone, 320°C to 850°C in the preheating zone, 1150°C to 1200°C in the roasting zone, and 800°C to 350°C in the cooling zone. , transported to the ceramsite warehouse for storage.

The raw materials used in the present invention are mainly sludge produced by sewage plants or bottom sludge dredged from lakes and rivers, and the water content of sludge is reduced to 45% to 55% by using geotechnical tube bag dehydration, and the sludge dehydration process consumes a lot of energy. Small size, after the bag is broken, take out the sludge and mix it with clay evenly, then extrude and granulate. The granulation is simple and easy to operate, and the formed ceramsite body has high strength. Dredging sludge from sewage plants and rivers and lakes has a high calorific value, and part of the heat when roasting sludge raw pellets comes from the combustion of organic matter in the sludge itself, reducing energy consumption. After drying and preheating, the sludge particles will not burst, and the fired ceramsite has a uniform structure, high strength and large specific surface area, which is suitable for biological ceramsite requirements or replacements for biological carriers in sewage treatment Sand and gravel are added to the concrete.

Description of drawings

Figure 1 is a system diagram of fired sludge ceramsite.

Detailed ways

Example 1

The dredged sludge at the bottom of Hangu Sewage Reservoir in Sino-Singapore Eco-city was dehydrated in a geotechnical tube bag. After the geotechnical tube bag was solidified and dried for 15 days, the moisture content dropped to 52%. Mix evenly in the mixer, extrude into an ellipse through an extruder, and then enter the rotary kiln for firing. After 50 minutes, the ceramsite from the kiln is transported to the ceramsite storage warehouse by the bucket transport vehicle.

Example 2

Use a sludge mechanical dehydration device to reduce the moisture content of municipal domestic sludge to 70-82%, and then reduce the moisture content to 50% through a drying device or natural drying, and mix the dewatered sludge with a mass ratio of 1:1. and clay, and then extruded into granules, which are sent to the feed port of the rotary kiln through a belt conveyor. The slope of the rotary kiln body is 4%, the kiln drum speed is 2.5 rpm, and the ceramsite firing cycle is 35 to 40 minutes.

Claims (1)

1. the system of a firing sludge haydite; It is characterized in that this system comprises sludge dewatering unit, mixing granulation unit, rotary kiln, haydite warehouse, fume treatment unit; Described sludge dewatering unit is provided with geotextile tube bag dewatering unit, adopts road vehicle that dehydrated sludge is transported to the mud bank; Described mixing granulation unit comprises mixer and Squeezinggranulator, and this element is connected with rotary kiln through belt driving means; Described rotary kiln slope 3.2%～4.5%, kiln tube rotating speed is 2～3 rev/mins, kiln temperature is distributed as 180 ℃～320 ℃ of arid zoness, 320 ℃～850 ℃ of preheating zones, 1150 ℃～1200 ℃ on roasting band, 800 ℃～350 ℃ of cooling zones.

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