On the ceiling of 7 Days Hotel, I saw a white circular device, which was very flat and didn't look like a smoke detector. What is that?

Fire sprinklers are generally not stainless steel or brass sprinklers, but water mist sprinklers. Under the action of heat, the fire sprinkler is started by itself according to the predetermined temperature range, or by the control equipment according to the fire signal, and the water is sprayed according to the designed sprinkler shape and flow. This is part of the sprinkler system.

There is a glass tube on each fire sprinkler to prevent water from coming out, and a certain pressure is maintained in the water pipe. There is a temperature-sensitive liquid in the glass tube. Once the glass tube is heated and burst, water will flow out, and the pressure in the water pipe will drop, which will drive the pressure sensor to start the whole fire fighting system, booster pump, alarm and so on.

Extended data:

Precautions:

1, the sprinkler should be arranged under the roof or ceiling, which is convenient for contact with fire hot air flow and is beneficial to uniform water distribution. When there is an obstacle near the nozzle, it should comply with the provisions of section 7.2 of this specification or increase the nozzle to compensate for the water spraying intensity.

2. The arrangement of vertical and drooping nozzles, including the spacing between nozzles on the same water distribution branch pipe and the spacing between adjacent water distribution branches, should be determined according to the water spraying intensity of the system, the flow coefficient of nozzles and the working pressure, and should not be greater than the provisions in Table 7. 1.2, and should not be less than 2.4m

3, clearance height is greater than 800mm, and there are flammable substances in the technical interlayer, nozzle should be set.

4. When the automatic sprinkler system is set in a local place, the nozzle should be set on the outside of the walkway or doors and windows connected to the adjacent place without automatic sprinkler system.

Baidu Encyclopedia-Fire Control spray head