Classification and introduction of incinerator

1. Exhaust gas incinerator

The incineration of waste gas is divided into direct combustion method (burning the combustible and harmful components in the waste gas directly as combustion materials, which is only suitable for purifying waste gas with high combustible components or high calorific value when burning harmful components. Because of direct Combustion is flame combustion, so the combustion temperature can reach above 1100°C), catalytic combustion method (under the action of oxidation catalyst, the combustible components or pyrolytic components in the exhaust gas are completely oxidized into CO2 and H2O to purify the gas), regenerative combustion method (use the heat released by the combustion of the auxiliary combustion material to heat the mixed gas to a certain temperature, so that the combustible and harmful substances can be pyrolyzed). The purpose is to burn and destroy organic gas at high temperature, decompose organic matter into inorganic matter (carbon dioxide and water), and realize waste gas discharge up to standard and combustion heat recovery and utilization.

When designing an exhaust gas incinerator, it is first necessary to have a clear understanding of the exhaust gas components to be incinerated, and determine the waste calorific value, incineration temperature, incineration method and control points for subsequent tail gas treatment.

2. Waste liquid incinerator

The waste liquid incinerator can handle all kinds of waste that can be pumped, and it is suitable for all liquid waste liquid, mud and sludge and other toxic substances. The structure of the waste liquid incinerator is determined by the type and characteristics of the waste liquid and the form of the waste liquid nozzle used. The atomization equipment is the key to the waste liquid incinerator, and the quality of the combustion is directly related to the waste liquid atomization device. Therefore, the design of the atomization device is the core part of the whole set of waste liquid incineration equipment, and the most suitable feeding method must be adopted in combination with the actual situation of the material. When designing the waste liquid incinerator, according to the composition and characteristics of the waste water, design the incinerator body with different shapes and furnace linings; design different furnace temperature control methods according to the salt content in the waste water to ensure that the inorganic salt does not hang in the furnace during incineration. The most suitable treatment method is adopted for the dust and acid gas generated during the incineration process to fully ensure that no new pollution will be formed after the waste water is incinerated.

3. Pyrolysis incinerator: mainly used for incineration of hazardous waste such as medical waste.

The pyrolysis furnace is a pyrolysis zone for medical waste under oxygen-controlled conditions. The waste is ignited by the burner to start burning. The air supplied by the supplementary air system is distributed in the lower part of the furnace, and the air volume is only 20% -40% of the stoichiometric oxygen required for waste combustion, so that only the waste located in the lower part of the furnace is completely burned, and the heat released by the combustion is transferred upward to the upper layer of waste. After heating, the heat is transferred to a higher layer, so that the waste gradually forms a embers layer, a combustion layer, a carbonization layer, a pyrolysis layer and a drying layer in the furnace from bottom to top, and the long molecular chains of various compounds are gradually broken into short molecular chains and become a flammable gas. Since there is not enough oxygen for further oxidation of these gases, these gases will enter the secondary combustion chamber for further combustion. The remaining combustible fixed carbon is gradually converted into CO2 due to the long stay in the furnace.

4. Rotary kiln incinerator

A rotary kiln incinerator mechanism

The rotary kiln incinerator is a cylindrical shell lined with refractory bricks, the axis of which is installed at a slight angle to the horizontal. Natural gas, oil or pulverized coal can be used as fuel. The rotary kiln was originally the main equipment used to process and manufacture solid substances such as cement, lime, iron ore, coke, etc., and was gradually applied to waste incineration, because it can effectively process various states (solid, liquid , sludge, etc.) have been widely used by industry. Rotary kilns usually have a very long kiln body, so that the combustion zone occupies only a small part of the entire incinerator. Most of the waste material is heated by gases produced during the fueling process and by heat transferred from the kiln walls.

The rotary kiln incineration system consists of a rotary kiln and a secondary combustion chamber to ensure complete combustion of waste. The rotary kiln itself is used to boil and oxidize the combustibles in the waste, and the inert solid in the waste moves to the other end with the rotation of the kiln body, and then is discharged from the bottom. The boiled steam and combustion gas pass through the back end of the rotary kiln and enter the secondary combustion chamber for oxidation at high temperature. The secondary air is supplied by a blower to increase the air/fuel ratio and the degree of turbulence. Both the rotary kiln and the second combustion chamber are equipped with auxiliary burners to maintain a stable temperature in the furnace. At the same time, there are waste liquid nozzles at the kiln head and the second combustion chamber of the rotary kiln, through which liquid hazardous waste can be sprayed into the device for incineration.

According to the flow direction of gas and solid in the rotary kiln, the rotary kiln incinerator is divided into two types: the same direction and the reverse direction. The reverse rotary kiln incinerator has better gas and solid mixing and contact, high heat transfer efficiency, and is conducive to increasing the combustion rate. However, due to the relatively high relative velocity of gas and solid, the amount of dust taken away by the exhaust gas is also high. The shape of the same-direction rotary kiln incinerator is not only suitable for the input and pre-treatment of solid waste, but also can increase the residence time of the gas, and it is easy to achieve airtightness. Most of the rotary kiln incinerators currently dealing with hazardous waste are of the same direction type.

The rotary kiln incinerator has mature technology, simple and flexible operation, and is suitable for processing solid and liquid wastes of various shapes, as well as hazardous wastes with low melting points. The rotary kiln can accept solid and liquid feeds separately, and can also send barreled or large block solid waste directly into the kiln for treatment. The gas turbulence in the kiln is high, the gas and solid contact are good, there are no moving mechanical components in the kiln, and the maintenance is easy. The residence time of solids in the kiln can be controlled by adjusting the rotational speed of the rotary kiln. The temperature inside the kiln can reach over 1200℃, which can effectively destroy any toxic and harmful substances.

B rotary kiln incinerator features

(1) The combustion chamber of the furnace body is designed according to the 3T principle of the incinerator. The furnace temperature is maintained at 850℃~ 1000℃. Incineration can fully oxidize and decompose the organic matter in the waste, so that the combustion and destruction removal rate can reach more than 99.99%, and it can be effectively controlled. Odor and nitrogen oxides are produced, so that the flue gas produced can achieve the effect of complete combustion without peculiar smell, stench and smoke.

(2) The inner volume of the furnace is large, and the load of the furnace is large, which is enough to cope with the co-firing of wastes with various calorific values, and the application range is wide and stable.

(3) Design negative pressure combustion, no backfire, avoid harmful gas leakage, safe and reliable operation.

(4) The rotating device of the furnace body is a frequency conversion speed regulating motor. Gear transmission, the overall rotary working state is stable.

(5) Furnace hearth is integrally poured with amorphous high-alumina refractory material, which is divided into heat insulation layer and heat storage layer to ensure that the temperature of the outer wall of the furnace does not exceed 70℃;the furnace body is designed to be inclined to ensure the uniform advance of the material drive in the furnace, but also to ensure that the furnace body has a small rotation vector; the furnace is poured into a certain slope, so that the material moves from the kiln head to the kiln tail under the action of gravity; stainless steel nails are used as internal fixing anchors and There is an expansion jacket to ensure the strength of the furnace pouring to adapt to the alternating thermal stress of the incinerator working state.

(6) The furnace wall is made of steel material, which is treated by shot blasting to ensure a good derusting effect on the surface of the material, and is painted with high-temperature anti-corrosion paint.