Water mist manufacturer says the difference between open water mist fire extinguishing system and closed water mist fire extinguishing system
 
 
Water mist manufacturer says the difference between open water mist fire extinguishing system and closed water mist fire extinguishing system
 
1. Closed sprinkler head is used in closed sprinkler head. The temperature sensing and locking device of sprinkler head will fall off and open the sprinkler head only in a predetermined temperature environment. Therefore, in the event of a fire, the sprinkler system will only be activated when the sprinkler is in the flame or near the source of the fire.
 
2. The open sprinkler head is used in the open sprinkler head. The open sprinkler head does not have temperature sensing and locking device, and is in the normally open state. When a fire occurs, all open sprinkler heads in the system protection area where the fire is put out water together.
Water mist manufacturer
3, open the valve parts and nozzle water spray system is different, the valve part is electric or manual, when fire alarm, fire alarm system and linkage control device of electric start valve, or manual valve to start, makes the valve opens and main line of water through the valve reaches nozzle jet fire.
 
4. The closed valve is usually closed, but there is water in the front and back of the valve. When the fire occurs, the high temperature makes the glass bubble of the closed nozzle break, and the water sprays out at the same time, the valve detects the decrease of the water pressure at the back, so as to send a warning signal to the alarm system, which linkage starts the fire pump to supply water.
 
5, the same is that they all belong to the automatic sprinkler system, and they should be linked to start the fire pump. The difference is that the action steps of spraying water are different, and the application places are also different. Because the reliability of the closed system is not high, the sprinkler head may be broken by external force, resulting in the wrong spraying, so it is set in some parts that are not sensitive to water.
 
The following is the difference and application between open and closed water mist systems
 

(1) Open system

 
Water mist manufacturer adopts open water mist sprinkler, which is controlled by automatic fire alarm system. After automatically opening the partition control valve and starting the water supply pump, water will be supplied to the sprinkler head.
According to the application mode of the system, the open system can be divided into two forms: full submerged application and local application.
In the case of full flood application, the small particle size and high spray pressure make the water mist droplets have certain fluidity and dispersion like gas, fill the whole space, and protect all the protected objects in the protection zone.
Local application mode is to directly spray fine water mist to extinguish fire in a part of the protected area, such as oil-immersed transformer and gas turbine bearings.
 
The system consists of high-pressure pump set, open water mist nozzle, partition control valve (open), system filter device, water tank, water supply pipe network and fire alarm device.
 
System features:

Usually there is no water in the system pipe network. When a fire occurs, the fire detector sends out fire signal and feeds back to the fire control center. After confirmation, the high-pressure pump group and the corresponding partition control valve group are automatically started to spray fire. Open system is a high-pressure water mist fire extinguishing form in the current application range. It is not only suitable for conventional building space protected by conventional gas fire extinguishing system, such as 3~6 meters space, but also suitable for industrial, commercial and civil buildings and other large or tall space, such as 10~20 meters space. It is also suitable for ships, military equipment, large traffic vehicles, commercial kitchens and other local places; It is especially suitable for some special low temperature and high temperature places, and it is especially outstanding for places with large fire risk level.
 
System application mode: According to the characteristics of protected objects and sites, open system can be divided into full-space application, local application and partition application. For some places with special requirements, if the spraying time is required to be timed in the protected area space, such as the automatic closing of the spraying time limit of 10 seconds, it can be realized by the timing control of the partition control valve.
 

(2) Closed wet system

 
Composition: the system consists of high-pressure pump set, closed water mist sprinkler head, partition control valve, system filter device, water tank, water supply pipe network, etc.
 
Features: the system at ordinary times is always filled with a certain pressure on the pipeline network of water, general pressure is less than 0.6 MPa, the tall building, also set up the holding pressure can reach 7 MPa, the entire network is a closed pipeline system, when the fire broke out, the glass ball is heated in automatic sprinkler burst, high pressure pumps, automatic start conversion form high pressure to spray; Only spray nozzle in the fire area (burst when heated), no spray in other areas.
 
Application: Closed system is suitable for slow horizontal spread of fire, low danger level of the place.
 

(3) Closed pre-action system

 
Features: the system composition and closed wet system basic same, the difference is that after preaction valve usually filled in the pipe network is gas or air, fire, fire detector device automatically open preaction valve and exhaust valve quickly make the pipe filled with water, after being spray fire partition glass ball burst, start the high pressure pumps, transformation form high pressure, spray extinguishing system.
 
Application: The pre-acting system is mainly used in places where pipeline leakage is strictly prohibited. It is suitable for places where the ambient temperature is lower than 4℃ or higher than 70℃.