The atmospheric pressure fixed experimental electric furnace generally takes lump anthracite or bituminous coal and coke as raw materials, and uses steam or the mixture of steam and air as gasifying agent to produce gasified gas with carbon monoxide and hydrogen as the main combustible components.
According to the characteristics of the production process in the furnace, the gasification reaction of solid fuel in the experimental electric furnace is divided into five layers: drying layer - at the top of the fuel layer, the fuel contacts with cold coal, and the moisture in the fuel is evaporated; Retorting layer - under the drying layer, due to the similar temperature conditions with the retort, the fuel is cold decomposed, volatile matter and other retorting products are released, and coke is transferred from the retorting layer to the gasification layer for cold chemical reaction; Gasification layer is the main area of the gasification process in the furnace, where the carbon and gasifying agent in the fuel react fiercely. In view of the different reaction conditions, the gasification layer can also be divided into oxidation layer and reduction layer.
In order to produce gas in fixed experimental furnace, firstly, the air passes through the fuel layer, and the carbon and oxygen react with each other to increase the temperature. Then the steam and air are mixed to pass through the fuel layer, and the carbon reacts with the steam and oxygen to produce gas.
From the principle of chemical reaction in the gas making stage of experimental electric furnace, we hope to form conditions favorable to steam decomposition and carbon dioxide reduction reaction. Therefore, it can be considered that it is advantageous to increase the thickness and temperature of gasification layer, and it is also advantageous to appropriately reduce the steam flow rate. In the chemical reaction of carbon and steam, increasing the thickness of gasification layer and reducing the gas flow speed can accelerate the reaction speed, increase the content of carbon monoxide and improve the steam decomposition rate.