Eight misunderstandings of boiler operation NO.1 you may be wrong

April 28, 2022

At this stage, most boiler accidents are caused by poor management and operation. Boiler operation has high technical requirements on people. And often the quality of the personnel engaged in this work is different, and there will be a variety of different understandings in the work.


Through decades of research on boiler production and manufacturing, EPCB has been rooted in the front line of users, and has summarized eight misunderstandings in the operation of boilers, so that people can recognize the misunderstandings when the boiler is running, improve the operation level, and make the boiler unit operate safely.


Misunderstanding 1: The higher the steam pressure, the better


The pressure value of boiler steam is mainly set by the user's needs. To make the pressure-bearing parts safe and beneficial, the energy consumption can only be reduced by reducing the air pressure, but the relative quality of the steam will be reduced, which will reduce the enthalpy and increase the humidity. Cultivation, sterilization, power generation and heating needs.


The energy consumption under high pressure will increase, and the pressure of piping, valves and corresponding gas-consuming equipment will also increase, which will make maintenance and maintenance higher. In the process of steam production and transportation, The leakage of steam and the loss of heat dissipation of the boiler are also large.


The operation of the boiler must be operated according to the specified working air pressure, and the fluctuation value of the air pressure is generally 0.05~0.15MP.


Misunderstanding 2: The higher the pot water level, the safer


In order to ensure the safety of the boiler, some people will raise the water level so that the boiler is not easy to run out of water. Actually this method is wrong. This method will endanger steam equipment and production, because after the water level is raised, the humidity of the steam will increase relatively, so the quality of the steam cannot be guaranteed.


For electric boilers, the steam generated by it has a large moisture content, which will erode the blades of the last stage of the steam turbine. .


Therefore, the water level of the boiler must be kept at 50mm as required.


Misunderstanding 3: The more fuel you add, the better


Some people add a lot of coal to increase the amount of steam produced. In fact, this method is wrong, and a large amount of coal entering the furnace will reduce the efficiency. The ratio of gas to air should be 1:9:14. When the amount of air in the boiler remains unchanged but there is too much fuel, many incomplete combustion products, such as carbon monoxide, will be produced in the boiler.


The boiler will show dark and weak flames in the furnace, and black smoke from the chimney, which often occurs. When the situation is serious, the pulverized coal furnace inside will put out the fire, and at the same time, the oil furnace will produce secondary combustion and burst pipes until the boiler stops working.


Therefore, it is not necessary to blindly add coal, and the fuel and air volume should be adjusted according to the corresponding ratio. You can determine whether it exceeds the standard by observing the fire, smoke color, and oxygen meter. If the smoke color of the chimney is light gray, the flame is bright yellow, and the barometer is stable, it means that the proportion of air-coal is appropriate and the condition is good.


Misunderstanding 4: The finer the coal particles, the better


On the one hand, the way to get the coal to burn well enough to get a good mix with the air is to make the coal finer. But for the boiler, a process is needed to make the coal finer, which will greatly increase the power consumption of pulverizing.


However, industrial boilers are not suitable for fine coal particles. If too fine coal particles enter the furnace, it will happen:

(1) The coal will be burnt out in an instant, making the combustion unstable, and the furnace will be relatively difficult to work continuously and stably; (2) The air between the grate is too large compared to the pulverized coal, which will cause the pulverized coal to leak. increase losses;

(3) When burning pulverized coal, the grate must be burned with the maximum power consumption, which will increase the power consumption;

(4) The pulverized coal will fly around in the furnace, which will increase the loss of fuel.


Therefore, an appropriate amount of water can be sprayed before the raw coal enters the furnace, because when the water is sprayed 8 to 12 hours before the coal is burned, the water can penetrate into the coal particles, and the water vapor produced at this time is triatomic gas, which is This kind of gas can strengthen the radiation of the flue gas, which is of great help to the fire, and can also reduce the loss of exhaust heat.


Misunderstanding 5: The faster the grate travels, the better


Most people still think that the faster the grate travels, the better, which is wrong.


As everyone said, when the traveling speed of the boiler is accelerated, the load of the boiler is also large, and the demand for fuel is relatively large. At this time, the coal gate has also been opened. However, when the speed of the boiler is accelerated, the load in the boiler is not large, and the air volume does not change, the furnace will have yellowing, darkening, unstable, and oxygen-deficient flames, and the heat will be relatively lost.


Therefore, the speed of the grate should not be too high.


Misunderstanding 6: The larger the negative pressure of the furnace, the better


The negative operating pressure of the furnace should be 10~20Pa as much as possible.

If the stress is too high, it will happen:

(1) The air leakage in the furnace becomes larger, and the loss of exhaust gas becomes larger;

(2) The power consumption of the fan increases;

(3) Dust will fly, which will increase the wear of the heating surface;

(4) The furnace efficiency of the boiler is reduced. During operation, the pressure of the furnace changes from negative to positive, and even increases the amount of induced air, making it difficult to change the pressure of the furnace to negative.


Misunderstanding 7: It is better to discharge the sewage longer


Sewage refers not to regular sewage discharge, but to discontinuous sewage discharge. Removing the slag, dirt and corrosion products at the bottom of the boiler is the main step of regular blowdown, which can reduce the scaling of the furnace tube, prevent the furnace tube from clogging, reduce the salt content of the boiler water, and improve the heat transfer effect.


Some people think that the longer the sewage discharge time, the more efficient the sewage discharge will be, and the more impurities will be discharged, but this is not the case. Because of prolonging the time of blowdown, a lot of heat will be wasted and the efficiency of hot steam pressure will be reduced; it will also reduce the water circulation efficiency of the boiler, and in severe cases, the water-cooled wall tube will burst.


Therefore, it is necessary to increase the number of sewage discharges as much as possible, and discharge them evenly every time, and set up professionals to operate.


Misunderstanding 8: The lower the exhaust temperature, the better


Low exhaust gas temperature is a good performance of boiler exhaust waste heat, but if the temperature is too low, some abnormal phenomena will occur. The exhaust gas temperature will be low; the flue air will be too high; the combustion efficiency will be reduced; the boiler load will become low.


Therefore, it is necessary to add a steam heater to the coal stove to increase the exhaust gas temperature.




Under specific boiler operating conditions. The staff should observe more. Continuously sum up experience and lessons, strengthen the safe operation management of boilers, in order to ensure the safe and stable operation of boilers.


At present, EPCB has more than 1,500 users around the world, covering more than 100 countries and regions! EPCB has been making continuous efforts to become the "preferred supplier of global industrial boiler complete systems"!


EPCB, your personal boiler system expert!

Further Reading:

Boiler Guidance----Acceptance After Boiler Installation

Industrial Boiler Low Load Operation Hazards,Causes and Solutions

Thermal Oil Boiler Safety and Energy Saving |Thermal Oil Boiler Scaling Causes, Hazards and Solutions

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