1. Project Introduction

Municipal sludge is a by-product of urban sewage treatment. On the one hand, urban sludge has large output, high moisture content, difficult moisture removal, and low harmlessness rate. Direct discharge is harmful to the environment, but its calorific value is high and can be utilized as resources. On the other hand, urban sludge has high requirements for reduction, and traditional sludge treatment methods, such as landfill, composting and incineration, have high requirements for sludge moisture content.

Hot drying method can be used for further dewatering of sludge, but traditional hot drying methods are expensive, and an economical method is urgently needed to replace the traditional hot drying method.

Sludge thermal hydrolysis technology can further efficiently and economically reduce the moisture content of sludge. This technology is based on the principle of cell wall breaking and can achieve sludge dehydration and drying with low energy consumption and high efficiency.

2. Technological innovation and technological leadership

This technical solution has the following characteristics:

(1) Homogenization and slurrying unit: The homogenization unit has several functions of storing, diluting and slurrying sludge. The unique homogenizer design and the mixing method of dilution water and flash steam allow the sludge to be quickly homogenized before entering the pump., convenient for subsequent transportation.

(2) Hydrothermal unit: In the hydrothermal unit, the sludge warms and increases pressure, and hydrothermal reactions occur. The reactor can be intermittent or continuous (including radial flow or tower). The unique reactor structure and stirring device make steam utilization efficient. High, rapid and thorough reaction, and effective separation of solids and liquids after reaction.

(3) Flash unit: The flash unit mainly plays the role of pressure relief and cooling, and the generated flash steam is passed into the homogeneous slurry unit for recycling.

(4) Heat exchanger: The unique heat exchanger structure can effectively prevent clogging. The temperature of flash sludge is reduced after heat exchange, which facilitates subsequent dehydration.

(5) Dewatering unit: The dehydration unit uses efficient pressure filtration technology to reduce the moisture content of the sludge after thermal hydrolysis to about 30%.

(6) Economy: The investment and operating cost is much lower than that of drying incineration technology (drying incineration investment: 25~500,000 yuan/ton of sludge with a moisture content of 80%; drying incineration operating cost: 225 - 490 yuan/ton of sludge with a moisture content of 80%).

After being treated by this technology, the shape and viscosity of the sludge have obvious changes, as shown in Figure 2. After thermal hydrolysis of sludge, the cells are broken, making it easier for water to be separated from sludge particles. After simple low-speed centrifugation (3000r/min), the water content after low-speed centrifugation can reach below 50% when the reaction temperature reaches above 170℃. If thermal hydrolysis After subsequent high-efficiency pressure filtration, the water content can be reduced to below 30% when the reaction temperature reaches above 170 ℃.

3. Market and Benefit Analysis

(1) Huge market capacity: During the "Twelfth Five-Year Plan" period, my country's investment in sludge treatment and disposal facilities will reach 34.7 billion yuan. In 2015, the national harmless treatment rate of urban sludge will be required to reach more than 50%(currently less than 1/4).), the demand market for urban sludge thermal hydrolysis equipment is more than 1000.

(2) Excellent economy: The investment and operating costs are lower than those of dry incineration technology, especially the operating costs are much lower than relevant subsidies, making the economy good.

(3) Good social benefits: During the treatment process of urban sludge thermal hydrolysis technology, the system is closed, no odor is generated, and the sludge reduction effect is obvious.

The daily processing of 100 tons of municipal sludge thermal hydrolysis equipment with a moisture content of 80%, the investment per set of equipment is 13 million yuan, the total investment is 18 million yuan, the total operating cost is 131 yuan/ton, and the corresponding government subsidy is 150~400 yuan/ton, sewage plant subsidy is 0~100 yuan/ton, the total subsidy is 180~400 yuan/ton.