The purpose of ignition is to ignite the fuel and burn it.The ignition operation of rotary kiln can be divided into: cold kiln ignition after kiln maintenance, normal kiln ignition (non-maintenance state), ignition after short flame-out, ignition immediately after the production process flame-out, etc.
There are generally two ways of ignition when the rotary kiln USES gas fuel as energy source: A.Place the torch (ignition source) at the lower end of the burner and conduct a programmed ignition.B. An automatic ignition (burner) device with a dedicated ignition source and electronic ignition is set on the exit end face of the burner, which can be automatically controlled by the program.
When solid fuels such as pulverized coal or heavy oil are used for ignition, it is difficult for general ignition sources to ignite the fuel in a short time due to the high ignition point of solid fuels.Therefore, before burning solid fuel (burners), a certain amount of wood or other combustible material should be piled up in the rotary kiln and under the outlet of the burner.Through the combustion of combustible matter, the space temperature in the kiln is gradually raised to a certain degree, which can gradually ignite the fuel and generate the temperature of automatic combustion.
When solid energy is used as fuel, when the temperature environment for ignition of the fuel is already available in the rotary kiln, consideration should also be given to how to ensure the combustible conditions of the fuel itself.For example: in the use of coal when the moisture, fineness, input volume, speed, etc.In the use of heavy oil viscosity, heating temperature, atomization and pressure, etc.These are the important guarantee conditions for how to complete the ignition and combustion of fuel.
The following figure shows the operation scene in the kiln when wood is used for ignition：
In the ignition operation with gas fuel as the energy medium, the basic requirement for fuel use is that there should be a working procedure with high control performance, fast and accurate reaction and automatic linkage in its transport and operation procedure.The main purpose of this is to ensure safety.
For example, when the initial fuel (gas) is ejected from the burner, if the spark fails to ignite the fuel in time and the fuel fails to terminate in time.Unterminated fuel with a certain amount of energy will continue to enter or gather in the rotary kiln.At this time, if it encounters the fire, the result will be that the fuel gathered in the kiln will catch fire and cause the positive pressure tempering to explode, which is very dangerous.
Therefore, the following basic principles must be followed when selecting gas fuel on the rotary kiln and firing no matter what kind of ignition method is adopted:
First, the ignition must be located below the outlet of the burner and in direct contact with the fuel;
Second, before the fuel is ejected from the burner, the ignition must exist and have sustainable combustibility;
Third, the time interval between ignition and fuel injection is not easy to be too long;
Fourth, the rotary kiln must form a certain (will not make the fire extinguish) negative pressure pumping force.
If one ignition fails, the next one is strictly prohibited within a short time or immediately;
Six, make the ignition as successful as possible.
Unsuccessful ignition (ignition failure) is common.There are many reasons for the failure, generally common are: ignition gas supply is not smooth, the ignition state is not good, the electrical system, valve position system linkage abnormal, fuel transmission blocked.At this point, the basic requirements before the next ignition are:
1. The exhaust machine shall replace the gas in the kiln, and the exhaust time shall not be less than 10 minutes;
2. The fuel source is finally off and in a state of repreparation;
Three, find out the cause of ignition failure;
Go back to the ignition procedure.
Among them, it is very important to find out the cause of ignition failure and the key to ensure the success of the next ignition.
Gas fuel ignition in particular to pay attention to safety issues, remember to ignition, and then gas!First fire, then air!First fire, then air!