A device and method for pyrolyzing sludge into charcoal based on microwave-induced directional heating technology

Abstract

The invention relates to a device for preparing charcoal by pyrolyzing sludge based on a microwave-induced directional heating technology, and relates to the technical field of resource utilization ofmunicipal sludge. The device comprises a primary pyrolyzing furnace, a microwave pyrolyzing furnace, a material mixer, a rotary shaft of a material containing tray, a material inlet, a pyrolyzing charcoal discharge port, a guide plate, a rotary material containing tray, a bottom furnace body, an outer furnace body, a pyrolyzing charcoal cooling device, a pyrolyzing charcoal discharge port, an inner furnace body and a sealing layer, wherein the primary pyrolyzing furnace and the microwave pyrolyzing furnace form an annular furnace body structure; the material mixer, the rotary shaft of the material containing tray, the pyrolyzing charcoal discharge port, the guide plate, the rotary material containing tray, the inner furnace body and the sealing layer are arranged in the annular furnace body; the material inlet is arranged on the outer furnace body; the pyrolyzing charcoal discharge port is arranged on the bottom furnace body. The device has the advantages that the rotary material containing tray is relatively still and continuously sent into the microwave pyrolyzing furnace, so that the utilization efficiency of high-energy sites is improved; the whole heating ability of the semi-pyrolyzed sludge in the microwave pyrolyzing furnace is improved; the continuous production of charcoal preparation by sludge pyrolyzing is realized.

Description

technical field [0001] The invention relates to the technical field of resource utilization of municipal sludge, in particular to a device and method for pyrolyzing sludge into charcoal based on the principle of microwave-induced directional heating and synergistic pyrolysis. Background technique [0002] As a product of sewage treatment, municipal sludge has complex components and large output, and has dual attributes of resources and pollution. Sludge contains organic matter, nitrogen, phosphorus and other resources, but it also concentrates about 50-80% of heavy metals in sewage, a large number of various parasites and pathogens and other pollutants. With the gradual improvement of my country's urbanization and sewage treatment standards, the municipal sludge produced in my country (with a moisture content of about 80%) reached 23 million to 45 million tons in 2016. Therefore, the safe, environmentally friendly, cost-effective disposal of a huge amount of municipal sludg...

AI Technical Summary

Problems solved by technology

However, sludge is a weak microwave-absorbing medium. Wet sludge consumes high-quality microwave energy for low-efficiency drying. It is difficult for dry sludge to reach high temperature in a short time directly in the microwave field.

However, the addition of a strong wave absorbing agent has high energy consumption costs for separation from pyrolytic carbon, and the risk of secondary pollution of heavy metals will increase due to the pulverization of the glass in the recycled sludge charcoal without separation, which hinders its continuous use in the future. Large-scale industrial production, so related work stays at the research stage

[0006] In summary, on the basis of safe solidification of heavy metals, energy-saving and efficient preparation of sludge carbon can help realize the high value-added resource utilization of sludge, but there are difficulties in the existing research on sludge carbonization

1) In order to reduce the volatilization of heavy metals in sludge, it is necessary to shorten the pyrolysis time, and to stably solidify heavy metals through vitrification, it is necessary to prolong the pyrolysis time at high temperature and improve the quality of carbon. efficient implementation

2) Although microwave pyrolysis can be heated rapidly, it is necessary to add a strong wave-absorbing medium, otherwise the temperature cannot be raised for a short time and it is difficult to ensure the safe solidification of heavy metals; and most of the existing microwave pyrolysis uses intermittently operated fixed-bed experimental devices. Fewer materials in batch processing, high energy consumption, and uneven mixing of materials

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