Discussion on the outlet plug valve of the weighing coal feeder
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Dear sea friends, it is difficult to operate the plug valve at the outlet of the weighing coal feeder in the pulverized coal gasification unit; as a result, it remains in the open position and does not close. What are the potential dangers of this? How can it be addressed fundamentally? I would appreciate everyone’s advice.
The outlet plug valve of this equipment is generally kept fully open, and needs to be isolated during maintenance. Another scenario is when there is a shortage of nitrogen in the equipment or when there is a significant leak; in such cases, it is necessary to shut down the system in order to prevent backflow of hot air from the coal grinder. If backflow occurs, the instruments in the weighing coal feeder will be damaged and the belts will age out. Personal opinion
Reply to 2# cj19700907: The outlet plug valve of this equipment is generally kept fully open, and it needs to be isolated during maintenance. Another scenario is when there is a shortage of nitrogen in the equipment or when there is a significant leakage; in such cases, it is necessary to shut down the equipment in order to prevent backflow of hot air from the coal grinder. If backflow occurs, the instruments in the weighing feeder will be damaged and the belts will age. Thank you for sharing your insights; they have been very helpful to me. The outlet plug valve of this equipment is usually kept fully open during normal operation, but it needs to be isolated when the grinder is stopped or during maintenance. Another scenario is when the circulation fan shuts down due to insufficient nitrogen or a severe leak in the equipment; in such cases, the system’s positive pressure needs to be reduced in order to prevent backflow of hot air from the coal grinder. If backflow occurs, the instruments in the weighing feeder will be damaged and the belts will age. Is that not a better solution?
Is yours electric?
Is yours electric?
Reply to 4# zhzhslh: It is electric; the gate plate gets stuck due to coal dust, and the switch often stops operating because of motor overload, which prevents the switch from reaching its proper position. It poses a danger to the weighing coal feeder and maintenance personnel, as well as causing damage.
Can this valve be removed? Some designs do not include this valve.
:There are two concepts: L coal pulverizer and wet grinder
Reply to 7# maoping421: Personally, I think it’s better to keep it in place, as this valve serves to isolate the system during mill shutdowns for maintenance purposes, allowing access to the feeder and the vibrating hopper. If this valve cannot be closed, it becomes very unsafe, as air can flow upward through the mill; waiting for the temperature to drop would result in a significant loss of time. Also, in the event of an emergency power outage and shutdown, the system temperature is very high and there is positive pressure in the system; as a result, gas rises to the coal feeder, damaging its belts as well as the instrumentation equipment.
Reply to 8# Shoulder: Yes, they are divided into coal pulverizers and slurry coal pulverizers.
The coal feeding weighing feeder for the coal storage hopper is equipped with a gate valve, while no valve is needed for the outlet leading to the coal grinder. Consequences and hazards: If the gate valve remains open continuously: 1. It will lead to the accumulation of a large amount of coal slag inside the valve, making it more difficult to open and close the valve in subsequent instances. 2. It will result in an excessive amount of coal accumulating on the belt of the coal weighing feeder, causing the belt to deform and get damaged.