Tubular furnace is a kind of industrial furnace, which uses electric current to heat the electric heating element or medium in the furnace to heat the workpiece or material.
Heat transfer mode of tubular furnace:
(1) the radiation heat transfer of furnace gas to metal, after the radiation heat of furnace gas is transferred to the furnace wall and metal surface, part of it is attracted and the other part is reflected back. The reflected heat is absorbed by the furnace gas filled with furnace gas, and the rest is radiated to the opposite furnace wall or metal, so as to radiate repeatedly.
(2) the radiation heat transfer from furnace wall and top to metal is similar to the previous one, and it is also continuous and repeated. The difference is that the inner surface of the furnace wall also absorbs heat in the form of convection, which is still transmitted in the form of radiation.
(3) convection heat transfer of furnace gas to metal. In the existing flame furnace, the temperature of furnace gas is mostly in the range of 800 ℃ ~ 1400 ℃. When the temperature of furnace gas is about 800 ℃, the effect of radiation and convection is almost equal. When the temperature of furnace gas is higher than 800 ℃, the convective heat transfer decreases and the radiation heat transfer increases sharply. For example, when the temperature of open hearth furnace gas reaches about 1800 ℃, the radiation part has reached about 95% of the total heat transfer.
The causes of water shortage accident of tubular furnace are as follows
1. The operators violate the labor discipline, sleep or fall asleep in the class, leave the operation post at will or do something irrelevant to the operation. When operating the boiler, the operators were not attentive, negligent and did not carefully monitor the water level. When the load of the tubular boiler increased, the water supply was not increased in time.
2. The operator's operation skill level is low, misjudgment, misoperation and mistaking water shortage as full water.
The water level is unreasonable, and the water level is not connected with the water level.
4. The water level is not clear due to poor illumination of water level gauge.
5. The alarm of high and low water level is out of order, no alarm or false alarm.
6. The two-color water level gauge fails.
7. For boilers with automatic feed water regulator, the automatic feed water regulator fails.
8. Boiler feed water valve or feed water check valve failure.
9. Boiler blowdown pipe and drain valve leak. During the operation of blowdown, the blowdown valve was not closed in time. There is foreign matter stuck in the drain valve core, which cannot be closed tightly.
10. In the boiler room with centralized water supply, when one water supply pipe is used to supply more than one boiler, due to the problems in the water supply system and operation system of the tubular boiler, the phenomenon of "water rush" between the boilers occurs, resulting in insufficient water supply for the boiler. Feed water pump, feed water pressure drop. The boiler tube or economizer pipe is broken or has a large amount of water leakage. The outlet valve of soft water tank is closed by mistake. Water source failure, etc.
Users should strictly follow the operation process to use the tubular furnace, so as to avoid damage to the furnace body and workpiece. I hope the above contents can help you. If you have more related questions, please pay attention to our website for browsing and viewing.