by This paper introduces the principle and structure of special components in automatic sprinkler system! 1.
Because the ambient temperature of the dry system is generally lower than 4 ℃ or higher than 70 ℃, if the system uses the ordinary droop nozzle, a part of water will remain at the short pipe of the unexploded nozzle, which cannot be discharged from the system smoothly.
The existence of this part of water will have the danger of freezing.
At this time, we can consider using the ordinary vertical sprinkler or the dry pendulous sprinkler.
If it is a ceiling place, we need to use the dry pendulous sprinkler.
Normally, the dry pendulous nozzle is composed of a section of sealed short pipe (length optional) and nozzle.
The inlet of the short pipe is sealed by a pipe plug with a gasket, and the glass bubble seals the inlet through the transmission pipe and pipe plug to prevent water from entering.
In case of fire, the closed sprinkler detects the fire, and the glass bubble bursts when heated.
The compression spring in the short pipe pushes the transmission pipe, opens the pipe plug, and the water flows into the short pipe, and sprays water through the sprinkler to extinguish the fire.
Such a structure can prevent water from entering the unexploded nozzle and solve the problem of water storage in the pendulous nozzle.
2.
The automatic exhaust valve is used because there is usually some air dissolved in the water, and the solubility of the air decreases with the increase of temperature, so that the gas in the water is gradually separated from the water and gathered together to form large bubbles or even gas columns.
At this time, in order to ensure that the pipeline is always full of water, it is necessary to continuously discharge the gas from the pipeline, so the automatic exhaust valve is used.
Automatic exhaust valves are generally used in wet systems.
When there is gas overflow in the system, the gas will climb up along the pipeline and finally gather at the highest point of the system, while the automatic exhaust valve is generally installed at the highest point of the system.
When the gas enters the cavity of the automatic exhaust valve and gathers at the upper part of the exhaust valve, the pressure will rise with the increase of the gas in the valve.
When the gas pressure is greater than the system pressure, the gas will make the water level in the cavity drop, the buoy will drop with the water level, and open the exhaust port; After the gas is exhausted, the water level rises, and the buoy also rises, and the exhaust port is closed.
In the same way, when negative pressure is generated in the system, the water level in the valve chamber drops and the exhaust port opens.
Because the external atmospheric pressure is greater than the system pressure at this time, the atmosphere will enter the system through the exhaust port to prevent the harm of negative pressure.
There is still one month to go before the fire test.
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