The difference between water mist nozzle and water mist nozzle

The water mist nozzle and the water mist nozzle are known from the names. These are two identical nozzles, and one nozzle is a bit small. In fact, they are the nozzles used by the two fire extinguishing systems. These two fire extinguishing systems not only have different nozzles, but also different places of use, working principles and compositions. Before understanding the difference between the two sprinklers, you first need to know what the system paired with them is. The water mist nozzle supports the high pressure water mist fire extinguishing system, and the water mist nozzle is combined with the water spray fire extinguishing system. Let's take a look at the difference between fine water mist nozzles and water mist nozzles.

1. Structural differences

The spray head is composed of the main body of the spray head, the nozzle, the nozzle core, the filter and other components. After a certain pressure of water enters the nozzle through the nozzle filter, the pressure water is ejected from the nozzle hole at a high speed to achieve the fire extinguishing effect.

For the impact spray head, the water spray consists of a splash plate, a diverter cone and a frame body. The pressure water flow is dispersed in the set area in the form of a uniform cone mist by impacting the external water splashing dish.

2. The diameter of the fog is different

Fog diameter: Fog volume % characteristic diameter of fog spray head is DV0.90, less than 1mm. That is, in the total volume of the spray liquid, the ratio of the volume occupied by the mist having the diameter or smaller is 90% or more.

The diameter of the fog: the diameter of the fog formed on the plane is less than 200m, Dv0.50 is less than 200m, and Dv0.99 is less than 400m. That is, on this plane, 99% of the fog is less than 400m in diameter, and 50% of the fog is less than 200m in diameter.

The diameter of the mist sprayed by the high-pressure spray head is smaller than that of the water spray, so it is more suitable for places with higher requirements for water immersion than the water spray fire extinguishing system, such as libraries and archives.

3. Basic principles

Comprehensively consider the influence of factors such as design spray intensity, protection area, and spray head characteristics.

Directly sprays water mist to completely cover the protected object.

The effective distance between the spray head and the protected object should not be greater than the effective range of the spray head.

4. Configuration method

The plane placement method of the spray head can be rectangular or diamond.

When configured as a rectangle, the distance between the spray heads should not be greater than 1.4 times the radius of the spray cone bottom of the spray head;

When configured in a diamond shape, the distance between the spray heads should not be greater than 1.7 times the radius of the base circle of the spray head.

5. Configuration requirements for the spray head to protect the transformer

When the protection object is an oil-immersed power transformer, the configuration of the spray head should meet the following requirements:

The orifice, oil pillow, radiator and oil collecting hole of the transformer rising seat should be protected by water mist nozzles;

The horizontal distance and vertical distance between spray heads should meet the requirements of the intersection of spray cones.

When the protection objects are A, B, C liquids and flammable gas tanks, the distance between the spray head and the outer wall of the protection tank should be less than 0.7m.

When the protection object is a spherical tank, the configuration of the spray head should meet the following requirements.

1. The mouth of the spray head must face the center of the ball;

2. The fog cone should cross the weft direction and connect with the warp direction.

3. When the volume of the spherical tank is more than 1000m3, the fog cone should cross the latitude direction and connect with the meridian direction, but the distance between the rings above the equator should not exceed 3.6m;

4. Spray heads should be set up at the steel pillars of spherical tanks without protective layers, tank level gauges, valves, etc. for protection.