Hydrogen sulfide incinerator is a professional incinerator for treating hydrogen sulfide tail gas. Its working conditions are very bad. The furnace is full of acidic gas, which is easy to cause serious erosion to the lining material. When designing the refractory material for the lining, the common factors of high temperature environment and acid corrosion medium should be fully considered. Therefore, the technical requirements for the lining material are as follows:
1. The normal working temperature of the furnace of hydrogen sulfide incinerator is right when it is working normally. In the actual production project, due to special working conditions such as fluctuations in materials and air volume, the furnace temperature may reach about 1400℃, so the lining material needs good high temperature resistance and softening temperature load.
2. Since the gas volume of upstream hydrogen sulfide is unstable, every fluctuation of the combustion situation in the furnace is a big thermal shock to the furnace lining. When selecting the material for the fire-facing surface, it is required to have good thermal shock resistance, that is, the seismic performance requirements are relatively high.
3. In order to control the temperature of the equipment shell, the lining material should have stable thermal conductivity when selecting.
4. The diameter of the furnace body is large, and the material needs to have good volume stability and creep resistance, and the reburning line change rate is small.
Selection of refractory materials
The working temperature of the incinerator is 1150℃, and the instantaneous maximum temperature can reach 1400℃. The main refractory structure of the furnace adopts a three-layer structure: ① The lining of the fire-facing surface adopts corundum-mullite bricks with good thermal shock performance; ② The middle layer of the lining adopts high-aluminum bricks LZ-55; ③ The outer layer of insulation bricks adopts high-aluminum insulation refractory bricks. In order to ensure the temperature of the steel shell, the outer wall of the equipment is added with an insulation layer.
01 Corundum-mullite bricks
Mullite refractory materials are the only stable binary mineral phases in the Al2O3-SiO2 binary system. Corundum-mullite bricks are high-aluminum refractory products composed of mullite as the main crystal phase and a small amount of corundum phase. They have good high-temperature strength, high-temperature creep resistance, thermal shock resistance and erosion resistance. Corundum-mullite bricks can use mullite particles as aggregates and α-Al2O3 powder as powders, or can use fused or sintered corundum particles as aggregates and synthetic mullite powder as powders. Aggregates and powders are mixed in a certain proportion and particle size distribution, and sulfite pulp waste liquid and other materials are used as binders. The materials are added in a certain order, fully mixed and evenly kneaded, and formed with a friction brick press or a hydraulic brick press. After the bricks are dried, they are fired at 1650~1750℃ to form finished products.
02 High-alumina refractory bricks
High-alumina refractory bricks (LZ-55) are a kind of aluminum silicate refractory made of high-quality high-alumina materials and clay as binders. They have high thermal stability and good slag resistance. High-alumina refractory bricks are generally formed and calcined from bauxite or other raw materials with high alumina content.
03 High-aluminum thermal insulation refractory products
High-aluminum thermal insulation refractory products have the characteristics of low bulk density, high porosity, low thermal conductivity and specific heat capacity, etc. They are mostly used in engineering to build the insulation layer (non-working layer) of industrial furnaces. High-aluminum thermal insulation refractory products are made of bauxite or other raw materials with high alumina content through molding and calcination.
04 Ceramic fiber blanket
According to Article "4.1.2" of GB50264-2013 "Design Code for Insulation Engineering of Industrial Equipment and Pipelines", the thickness of the insulation layer of the parts to prevent burns should be calculated according to the surface temperature method, and the temperature of the outer surface of the insulation layer shall not exceed 60℃. The outer wall of the steel shell of the incinerator uses ceramic fiber blanket as the external insulation material, which can not only improve the insulation effect, increase the metal wall temperature, but also play a role in high temperature protection.
Selecting suitable lining materials, reasonably setting the thickness of each layer of masonry and external insulation, and controlling the shell temperature can effectively improve the corrosion resistance of the incinerator, effectively ensure the long-term safe and reliable operation of the incinerator, and extend its service life.
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