What safety facilities does hot dip galvanize furnace set commonly have?
(1) safety facilities for maintaining furnace pressure:
Maintaining the positive pressure of the atmosphere in the furnace is an essential measure to prevent H explosion and ensure the quality of galvanized steel strip. In order to maintain a certain furnace pressure, the furnace is equipped with the following facilities:
A. when the fault stops, in order to avoid burning out the strip steel, the main burner of the preheating furnace will be automatically closed by an electric-pneumatic switch.Due to the reduction of combustion exhaust gas in the preheating furnace, negative pressure is likely to be generated in the furnace. In order to avoid negative pressure, two N pipes should be set up on the wall at the end of the preheating furnace, which can be opened automatically by pneumatic switch and filled with N to replace combustion exhaust gas in the preheating furnace to maintain positive pressure in the furnace.Simultaneously filled with N, it can cool the action of strip steel in the preheating furnace.
B. When the protective gas station fails and the protective gas is to be stopped, N pipelines with corresponding flow rate should be set at the end of the furnace to deliver N2 to the furnace to maintain pressure.At the same time, N input from the end of the furnace, the role of gas knife washing furnace chamber.
C. In order to make the flue gate controlling furnace pressure work normally, corresponding safety facilities should be installed on the gate.Generally, mercury indicator thermometer is installed in the pipeline of cooling water to control and check the temperature of cooling water.If the flue gate overtemperature of the cooling water pipe (> 70 ℃), then can cut off the preheating furnace automatically by the control system the main burner, and provide an alarm.
(2) gas safety facilities:
In normal production, often appear gas, air or gas, air pressure is insufficient accident.In order to prevent explosion or gas poisoning, safety shutoff valves should be installed on gas pipelines of preheating furnace and reducing furnace.If the pressure of gas or air is too low or too high, the safety shutoff valve should be able to close automatically immediately
(3) safety facilities of rapid cooler:
Damaged fast cooler temperatures often, therefore, fast cooling system should be installed on the instructions to control the cooling water thermometer and check, if the fast cooling system in the working temperature of cooling water temperature more than fast tanks (70 ℃), belongs to the system's cooler protective gas circulation fan should be able to stop automatically.
4) explosion-proof facilities in case of accident:
We have known that H and 0 will explode only when they are mixed and ignited at low temperature. Since the furnace temperature is very high during the production of preheating furnace and reducing furnace, even if the furnace is not closed, the small amount of 02 running into the furnace will immediately burn with H without explosion.
But for cooling section of the tail furnace temperature is low, and far less than H ignition temperature (585 ℃), if there is an accident, once falling furnace pressure or stove is not sealed, the air entering the furnace mixed with H after explosion occurs when it is heated, therefore, at the end of the cooling section set has the following facilities: a, resistance ignition zone: resistance ignition zone general arrangement in the furnace tail at the top or side of the wall, in the production
the resistance ignition belt has been in a working state, once a small amount of 02 entered, by the ignition belt will enter the furnace 02 and H ignited and burned.
B. Ignition belt should also be set on the curved nose of the furnace tail, because this area is prone to negative pressure. In addition, once the zinc pot is broken and the liquid level drops, the resistance ignition belt will ignite and burn the air entering the nose, thus avoiding air entering the furnace.
C. Bursting disc: at the top of the steering roller at the end of the furnace, the horizontal furnace is generally equipped with bursting disc to prevent the explosion of the whole furnace, which is a safety device for the furnace in special emergency.If the protective gas to the furnace and N should be interrupted at the same time, the bursting disc will be destroyed manually, so that a large amount of air from here into the furnace combustion, and finally the entire furnace H completely burned.