How to choose reasonable combustion method for muffle furnace

How to choose reasonable combustion method for muffle furnace

In the field of muffle furnace, the existing combustion methods are analyzed and improved, and the new combustion methods are discussed and tested in order to continuously improve the fuel utilization rate and the technical level of combustion equipment.

Combustion refers to the process in which the combustible components (carbon, hydrogen, sulfur and hydrocarbons) in the fuel combine with oxygen in the air and produce intense chemical reaction at a certain temperature to release light and heat. Complete combustion refers to the combustible components in the fuel, which are suitable for both air supply and supply method, so that no black smoke is emitted and all combustion is carried out. Otherwise, it is incomplete combustion.

1. In order to make muffle furnace reach the economic operation index, the problem of complete fuel combustion should be solved.

2. High enough furnace temperature

Temperature is the primary condition for fuel combustion. The minimum temperature at which the fuel begins to undergo a violent oxidation reaction is called the ignition temperature. The heat required to heat the fuel above the ignition temperature is called a heat source. The heat source of fuel ignition in combustion chamber usually comes from heat radiation of flame and furnace wall and contact with high temperature flue gas. The furnace temperature composed of heat source must be kept above the ignition and combustion temperature of fuel, that is to say, the furnace temperature must be high enough for continuous combustion of fuel. Otherwise, the fuel will be difficult to ignite, unable to burn, or even cut off.

3. Proper amount of air

Fuel must be fully contacted and mixed with enough gas in air when burning. When the furnace temperature is high enough, the combustion reaction speed is very fast, and the oxygen in the air will be consumed quickly. Therefore, sufficient air must be supplied. However, in actual operation, the air sent into the furnace is surplus, but the excess air quantity cannot be too much, so it should be appropriate to avoid reducing the furnace temperature.

4. Sufficient combustion space

Combustible materials or fine coal chips volatilized from the fuel will burn while the flue gas flows. If the furnace space (volume) is too small, the flue gas flows too fast and the flue gas stays in the furnace for too short, the combustible materials and coal chips can not be fully burned. Especially when the combustible materials (combustible gas, oil droplets) touch the heating surface of the boiler before the complete combustion, the combustible materials are cooled below the ignition temperature and can not be completely burned, forming carbon nodules. At the same time, sufficient combustion space is ensured, which is conducive to the full contact and mixing of air and combustible materials, so that the combustible materials can be fully burned.

5. Enough time

It takes a certain period of time for the fuel not to ignite until it is completely burned out, especially for the layer combustion furnace. The larger the combustion particles, the longer the combustion time. If the combustion time is not enough, the fuel will not burn completely.