Method for applying sludge heat drying and sludge digestion fermentation in combining way

Abstract

The invention relates to a method for applying sludge heat drying and sludge digestion fermentation in a combining way; a condensing-type heat exchanger is arranged between a sludge heat drying system and a sludge digestion fermentation system and is divided into a high temperature end and a low temperature end, wherein the high temperature end is connected with the sludge heat drying system, andthe low temperature end is connected with the sludge digestion fermentation system; when in the process of sludge heat drying, high temperature steam or high humidity gas generated by the sludge heatdrying system enters into the high temperature end of the condensing-type heat exchanger for heat exchange, the temperature of the gas is reduced to be 40-50 DEG C, and the moisture in the gas is condensed to form condensate water; liquid in a digestion system at the low temperature end of the condensing-type heat exchanger is heated, and the heating temperature is more than 35 DEG C; the liquid is then transmitted into the sludge digestion fermentation system connected with the condensing-type heat exchanger and used for supplying the heat needed in the process of sludge digestion fermentation; the sludge digestion fermentation system is connected with the sludge heat drying system by a pipeline, so that methane generated by the sludge digestion fermentation system is input into the sludge heat drying system to be taken as fuel for heating sludge.

Description

Technical field: [0001] The invention relates to a combined application method of thermal drying of sludge and sludge digestion and fermentation, which uses the heat energy of high-temperature steam or high-temperature and high-humidity gas generated in the process of drying urban sludge to heat the sludge digestion and fermentation system technology, thereby replacing the role of the heating system in biogas production, saving the daily heat energy consumption of the system and reducing operating costs. The invention belongs to the technical field of environmental protection and pollutant treatment. Background technique: [0002] With the rapid development of my country's national economy, the continuous acceleration of urbanization and the increasing public demand for environmental quality, a large number of urban sewage treatment plants across the country have been built and put into operation, facing the problem of how to deal with the large amount of surplus sludge gene...

AI Technical Summary

Problems solved by technology

[0004] 2. Agricultural method: This method is relatively stable and hygienic. It can convert part of the organic matter in the sludge into soil modifier components, and has a certain repairing effect on land reclamation, but it still has certain limitations.

One is poor degradability, high water content and low porosity, so a large amount of treatment chemicals need to be added

Heavy metal pollution exists in the sludge of many sewage plants, and seepage of heavy metals, pathogens, refractory organic matter and N, P in the sludge pollutes surface and groundwater

Second, the transportation costs required are relatively high

Due to the small amount of biogas produced, it is difficult to realize economically valuable biogas utilization

[0014] In summary, sludge drying is a method of sludge treatment, which is widely used at home and abroad. The sludge after drying treatment has good stability and no odor; the volume and weight are greatly reduced and easy to transport; after high temperature treatment The sludge sterilization degree is high; however, the sludge drying and sludge biogas processes are two independent processes, there is no connection between them, and the energy has not been used multiple times and effectively

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