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The function of the air blast is to enable a reaction between C and O2 that releases heat, thereby raising the temperature of the fuel layer and preparing it for gas production. During the blowing phase in a gas generator, the following reactions occur: (1) C + O2 = CO + Q, (3) 2CO + O2 = 2CO2 + Q, (2) C + O2 = CO2 + Q, and (4) CO2 + C = 2CO – Q. The first three reactions are exothermic; a high oxygen content, meaning a larger amount of air, facilitates the reaction rate. The high heat accumulated in the fire zone helps to increase the steam decomposition rate during the gas production phase, thereby increasing the amount of gas produced. In actual production, the temperature of the gasification zone is generally maintained between 1000 and 1200°C, which is close to or slightly below the ash melting point of the fuel, in order to achieve high gas production efficiency while ensuring that the blowing efficiency is not too low and thus allowing for a high gasification rate. The total amount of air fed into the furnace determines the production capacity of the gas generator, and this capacity can be controlled by adjusting the speed of air supply and the duration of the blowing process. As can be seen from the above reactions, increasing the blowing speed shortens the contact time between CO2 in the blowing gas and the red-hot carbon; as a result, less latent heat is carried away in the form of CO in the blowing gas compared to when a lower blowing speed is used at the same temperature. Therefore, increasing the blowing speed helps to improve the efficiency of gas generation as well as the gasification capacity of the gasifier. Whether it is possible to reach a high temperature in the fuel layer in a shorter time depends on whether the air blower can provide a higher air flow rate and whether the fuel layer allows such an increase in airflow rate. To achieve a high temperature, increasing the air flow rate is the main approach, provided that this does not cause damage to the fuel layer (such as it being blown over). When the air flow velocity has reached the upper limit of the allowable range for the resistance of the fuel layer and its distribution, as determined by the properties of the fuel, increasing the temperature of the fuel layer should be achieved by extending the blowing time. The properties of the fuel are closely related to the distribution of the blowing time; for fuels with good mechanical strength and thermal stability and uniform particle size, the resistance distribution within the fuel layer is even and relatively low, which facilitates an increase in air flow velocity, allowing the fuel layer to reach high temperatures in a shorter amount of time. Conversely, fuels with poor mechanical strength and thermal stability exhibit high resistance in the fuel layer as well as uneven distribution; increasing the airflow velocity can easily cause the fuel layer to be blown over, so a longer blowing time is required to achieve high temperatures. This post was last edited by ryn on 2009-3-1 17:18]