(1) Charring operation of tubular furnace
A: Principle: at the temperature of the furnace tube, the coke falls apart under the impact of the high temperature steam and air. The coke falls off reacts with the air and burns. The combustion products and the unburned coke powder are brought to the charred tank by the mixed air flow, and mixed with fresh water in the charred tank and then go away.
B: Objective: The heat transfer efficiency of the furnace tube can be improved and the service life of the furnace tube can be prolonged after burning in the furnace.
(2) Preparation
A: Prepare the charring process and make sure the charring process is smooth. (See Appendix IV)
B: Maintain fuel gas pressure. Direct fuel gas to *** nozzle before double valve.
C: fresh water, steam, industrial air (steam pressure > 0.7MPa, industrial air pressure 0.4MPa).
D: Contact instrumentation personnel to check the instruments used.
(3) Tube furnace stripping and coke removal stage
A: Steam is provided at the entrance of the furnace tube, steam is provided by four feeding lines in front of the convection chamber, and two furnaces are ignited for heating.
B: When the furnace chamber is lower than 500℃, the temperature rising speed is 40℃/h, until the temperature rises ***550℃.
C: When the furnace temperature reaches 350℃, open the steam valve fully.
D: Observe whether there is coke powder in the opening of the charred pot.
E: The temperature of the furnace reaches 550℃. When the coke free powder appears, the small furnace tube can be turned down to provide steam for air burning.
(4) Air burning stage:
A: Open the fresh water valve of the charred can and fill it with fresh water.
B: Turn down the steam and open the industrial air valve for charring. Do not pass into the air too much at a time, so as not to cause excessive burning furnace tube decarburization, or cause coke blockage furnace tube.
C: Strictly control the furnace temperature < 550℃.
D: Scorch normal judgment:
Tube furnace tube dark red normal, such as pink indicates that the temperature is too high, should be appropriate to reduce the amount of air, give some steam, until the furnace tube
Change from dark red to black red for good cooking.
The diameter of the coke powder blown out by the burning vent should be < 2mm, otherwise adjust the air volume, it is easy to cause the furnace tube blockage due to too large.
Burn out the furnace tube.
The smoke in the air is grey and black.
(5) Scorch end.
In the burning process, observe the coke outlet situation. When there is almost no black carbon, it means that the burning is finished, the furnace tube is flushed with steam for one hour, and the heating furnace begins to cool down with the speed < 50℃/h. When the furnace temperature drops to 200℃, the furnace can be shut off. Stop the steam and continue to pass the industrial air. When the furnace temperature drops to 100℃, open the flue damper and the first and second damper quickly, and the furnace will naturally cool down. When the furnace temperature drops to room temperature, stop the industrial wind.
On 2018-08-08 11:45:46
