The incineration system is mainly the core process in waste incineration treatment. Currently, the equipment used in waste incineration projects mainly includes mechanical grate furnaces, fluidized bed incinerators, and rotary incinerators.
Garbage enters the inclined downward grate through the feeding hopper (the grate is divided into a drying zone, a combustion zone, and a burnout zone). Due to the staggered movement between the grates, the garbage is pushed downwards, causing it to pass through various areas on the grate in sequence (when garbage enters from one area to another, it plays a big turning role). The odor generated by the fermentation and accumulation of garbage is extracted from the upper part of the garbage storage pit through a primary fan, and then heated by a steam (air) preheater to serve as combustion air and sent into the incinerator, ensuring that the garbage is dried and treated in a short period of time. Combustion air enters from the lower part of the grate and mixes with garbage; The high-temperature flue gas generates hot steam through the heating surface of the boiler, and the flue gas is also cooled. Finally, the flue gas is treated by the flue gas treatment device and discharged.
There is no need to add coal or other auxiliary fuels, resulting in relatively less coal slag. Moreover, its capacity is relatively large, and there is no need to classify garbage during treatment. Through the mechanical application of the grate, the stable combustion of garbage in the furnace can be ensured, and the combustion process is relatively complete, gradually reducing the thermal burning phenomenon of the slag.
However, mechanical grate incinerators have high initial investment, operation, and maintenance costs, and the wear and corrosion of the grate plates are more severe. Therefore, in the process of selecting waste treatment technology, it is necessary to systematically analyze the advantages and disadvantages of this technology to ensure the safety and efficiency of waste treatment.
The principle of combustion is mainly through fluidized bed technology for garbage combustion and safe disposal with the help of sand.
In the process of fluidized bed incineration of garbage, it is necessary to crush the garbage to achieve a certain particle size state. Through short-term fluidized incineration, it is treated in a short period of time using the action of combustion air. During the incineration process, air will be sprayed in from the bottom of the fluidized bed and the sand medium will be stirred reasonably to form a fluidized state of the waste. The system board is equipped with inert particles that carry heat and distribute air under the bed, causing the inert particles to appear in a boiling state and forming a fluidized bed section.
The efficiency of fluidized bed incinerators is relatively high, with a removal rate of only 1% for unburned materials. During combustion in the furnace, there are no mechanical moving parts and the durability is relatively good, which can extend the service life of the machinery.
However, fluidized bed incinerators mainly rely on air for garbage treatment and combustion, with particle size requirements for the incoming garbage. The boiling state of garbage in the furnace relies entirely on high air volume and pressure, which poses problems such as high power consumption and large production of ash, bringing a certain load to downstream flue gas purification. And in the process of operation and operation, professional skills are relatively high.
The rotary incinerator is arranged along the furnace body with cooling water pipes or refractory materials, and the furnace body is horizontally placed and slightly tilted. Through the continuous operation of the furnace body, the garbage inside the furnace is fully burned, while moving towards the inclined direction of the furnace body until it is burned out and discharged from the furnace body.
High equipment utilization, low carbon content in ash, low excess air, and low emissions of harmful gases. But combustion is difficult to control, and it is difficult to burn when the calorific value of garbage is low.