Organic solid waste pretreatment system and process and corresponding organic solid waste continuous hydrothermal treatment system and process

Abstract

The invention discloses an organic solid waste pretreatment system and process and a corresponding organic solid waste continuous hydrothermal treatment system and process. The organic solid waste pretreatment system comprises a weight sorting-smashing device and a ball milling device; the water weight sorting-smashing device comprises a sorting cavity and a second-stage smashing unit, separationof light materials and heavy materials can be achieved through the sorting cavity, smashing the light materials by the second-stage smashing unit is carried out to prepare primary mud, the ball milling device receives the primary mud and carries out ball milling to prepare mud containing impurities, the heavy materials separated by the sorting cavity can enter the ball milling device to be used asabrasive materials. The organic solid waste pretreatment system is simple and reasonable in structure, facilitates separation of light and heavy materials and utilization of heavy material waste, refines, homogenizes and fluidizes organic solid waste, can achieve organic solid waste synergism, high efficiency and continuous hydrothermal treatment, effectively prevents continuous hydrothermal technology blockage and the like, fully recovers heat energy in the technological process, and improves the utilization rate of organic solid waste, resource utilization of products can be realized, and obvious environment-friendly and economic benefits are obtained.

Description

technical field [0001] The invention relates to the technical field of organic solid waste treatment and disposal, in particular to an organic solid waste pretreatment system and process, and a corresponding organic solid waste continuous hydrothermal treatment system and process. Background technique [0002] With the rapid development of urbanization in my country, the total amount of organic solid waste produced in my country's cities has been rising steadily. According to reports, in 2019, the amount of municipal solid waste generated exceeded 200 million tons, and the total amount of municipal sludge was about 60 million tons. In the foreseeable future, the total amount of urban organic solid waste will continue to rise. According to statistics from the Ministry of Ecology and Environment, in 2017, among the 202 large and medium-sized cities, the amount of municipal solid waste generated in Beijing ranked first in the country, reaching 9.018 million tons, accounting for ...

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Problems solved by technology

However, there are the following problems: generally adopt storage tank type intermittent treatment, occupy a large area, long residence time (15-20 days), complex process, biogas needs desulfurization treatment, power generation needs to increase equipment such as boilers, generators and power grids, investment and High operating costs, low and unstable biogas output, strong and unstable final product odor, a large amount of digested biogas slurry with poor dehydration, anaerobic digestion consumes carbon sources in organic solid waste, and further reduces the carbon-nitrogen ratio in the biogas slurry , resulting in difficulty in denitrification of biogas slurry, high standard discharge cost, unstable digestion operation, foam in the digester, and digested mud cake (20-50% of the original sludge volume) still need to be disposed of through land use or incineration

The municipal sludge adopts the "drying + incineration" scheme. The drying and incineration process can completely carbonize the organic matter and minimize the sludge volume. The main problems of the incineration method are the large one-time investment, high equipment cost, and the calorific value of the sludge. Relatively low, lower furnace temperature, high operating costs

The main disadvantage of this method is that in the process, the steam of the high-temperature sludge (160-200°C) in the thermal hydrolysis reaction tank is used to preheat the sludge in the slurry tank to 90-100°C, which causes a large amount of The heat energy in the process is not recovered and wasted in vain, so the energy consumption of the process is very high. This is mainly because the tank-type hydrolysis process is difficult to achieve sludge flow and heat exchange

Partial continuous thermal hydrolysis methods such as patents: CN201110319442.9, CN201510924541.8, using reactor structure for thermal hydrolysis, sludge residence time is longer

In addition, patent CN201010247557.7 discloses a sludge tubular thermal hydrolysis treatment method and its device. When the thermal hydrolysis reactor adopts a tubular reactor, the problem of steam injection into the sludge is more prominent. If the tubular reactor Arranged horizontally, the steam and sludge may have a tendency to flow in layers, that is, the steam flows in the upper layer and the sludge flows in the lower layer, resulting in uneven heating of the sludge

Patent CN201410133371.7 discloses a radial flow hydrothermal reactor for sludge thermal hydrolysis treatment, and CN2014101333751.0 a continuous tower reactor for sludge thermal hydrolysis treatment, sludge flow There are many dead angles in the process, which is easy to cause fouling and blockage under high temperature of sludge

[0012] It can be seen that the existing thermal hydrolysis technology generally has the following problems in the treatment of organic solid waste with high solid content: poor heat transfer effect, uneven heating of materials, long residence time, and large steam consumption, especially in pipelines and equipment. Blockage and fouling, poor stability and reliability of continuous operation, and the resulting problems of high equipment investment cost, high operating cost, and long treatment cycle

However, organic solid waste is not only large in particle size but also very uneven. Even urban sludge with relatively fine particle size may contain plastics, branches and leaves, hair, and woven bag filaments with large particle sizes or long lengths. Etc., off-site transportation even includes some large-grained lumps, such as wood blocks, stones, glass flakes, etc., the particle size distribution is at least from microns to centimeters, and the particle size of paper packaging materials is generally not greater than 0.1 mm. It cannot meet the standard specification requirements for raw materials of paper packaging materials, and cannot be directly used as raw materials for paper packaging materials

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