Coal fired boiler is one of the most essential equipment of major industrial plants today, so what is a coal fired boiler? How to use coal fired boiler? Please read with KS-Boiler to find out information through the article below.
What is a coal fired boiler?
Coal fired boiler is an industrial boiler that uses coal fuel to boil and form steam commonly used in the industrial field. Depending on the needs of use, the steam source will have the appropriate temperature and pressure. Because the temperature and pressure are often very high, it is common to use specialized pipes that can withstand high heat and pressure. Coal-fired boilers are distinguished by their ability to generate safe, non-combustible sources of energy to operate equipment near fire or power sources.
How many types of coal fired boilers?
Due to the difference in structure and operating principle, coal-fired boilers are divided into two types: chain grate coal-fired boilers and fix grate coal-fired boilers.
So what is grate? The grate is an important part of most boilers located in the combustion chamber. The burner is the metal part where the fuel is placed on the surface to ignite and generate heat.
Application of coal fired boiler
Each type of coal-fired boiler has structures, characteristics and operating principles suitable for many different industries. Coal-fired boilers are used in many industrial plants to provide and direct heat and steam sources to the machines that need to be used. Coal fired boilers are commonly used in industries such as textile, garment, food, soft drinks, alcohol, seafood, fish sauce, soy sauce, etc.
What should be paid attention to during boiler operation?
Control wind and smoke.
Wind and smoke at low temperature have a large density, so it can increase the load of the exhaust fan, causing overload when opening the air valve. Therefore, when the combustion chamber temperature is still low, the exhaust fan must not be operated with the air valve wide open and the operation of opening the air valve must be done slowly to ensure the safety of the fan. The amount of wind required for combustion and the smoke produced is proportional to the mass and combustion of the fuel. The rated load of the electric motors is calculated for the full-load operation of the boiler at its operating temperature of 750 to 850oC.
The fan provides air for fuel combustion. Its air valve is adjusted in accordance with the amount of fuel fed into the furnace to maintain the optimal working temperature of the combustion chamber.
The exhaust fan is adjusted only to maintain the combustion chamber pressure always between -2 and -5 mm head water.
The amount of fuel supplied to the furnace is controlled by adjusting the fuel feed rate to match the load capacity of the boiler and is evenly loaded throughout the combustion chamber.
When changing the amount of fuel supply over a wide range, it is necessary to appropriately adjust the exhaust fan and fan blower valves to maintain the optimal state of the combustion chamber.
Smoke temperature control.
The smoke temperature indicator and control helps us to know the current temperature of the smoke stream and acts to stop the furnace when the excessive smoke temperature has been reached (in the range of 280 to 3000C) to ensure the safety of the boiler (stop all both fans and fuel feeders).
Excessive smoke temperature can be caused by water being depleted or the combustion chamber is too intense, the combustion chamber temperature is too high to be controlled. Therefore, when the smoke temperature is high, the furnace must be stopped to find out the cause and overcome before operating the furnace again.
Control the temperature of the combustion chamber.
The combustion chamber temperature is indicated and controlled by the temperature controller. It indicates the current temperature of the combustion chamber, alarms with a buzzer and acts to stop the fuel feeder when the combustion chamber temperature is too high or too low. At that time, the fans are still running, the fluidized bed is still maintained so that the operator can continue to operate the boiler gradually returning to the normal operating mode.
In order for the temperature controller to correctly report the temperature of the combustion chamber and not to operate it incorrectly, it is always necessary to ensure the fluidized bed state of the combustion chamber, especially in the vicinity of the two temperature readers. At the same time, good contact at the wiring points must be ensured and the conductors from the temperature controller to the temperature readings must not be shorted when pushing and pushing those readings while operating the oven.
Steam pressure switch.
The steam pressure switch stops the oven when the pressure rises above the set level and automatically restarts the oven when the furnace pressure drops to a lower set level.
Maintaining the above fluidized bed state, the two temperature readers must have a good fluidized bed to measure the true temperature of the combustion chamber. Keep the fuel burning evenly and keep the combustion chamber temperature slowly rising to the fuel supply temperature. At this stage, if the combustion chamber temperature cannot be increased or rises too slowly, reduce the wind accordingly, if the temperature rises too quickly, increase the wind accordingly. C.
Observe the temperature of the fire chamber to gradually increase the pressure of the fan, adjust the exhaust fan accordingly to have a pressure of -2 to -5mm of water column. Simultaneously with the process of gradually increasing the fuel supply speed to gradually increase the combustion chamber temperature. At this point, the fuel has reached the state of completely fluidized bed, the furnace begins to burn stably. When the combustion chamber temperature reaches 700 to 7200C, the process of controlling the air valves is finished to maintain a stable fluidized bed of the fuel. From this stage, only the fuel rate is adjusted to control the stable combustion chamber temperature in the range of 800 to 8500
When you see steam coming out through the air release valve (auxiliary steam valve), let the steam blow out all the air in the steam chamber, then close the air release valve. Observe the pressure gauge, if the furnace pressure reaches the working pressure, open the main steam valve to mix steam for production.
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