Water-mist fire curtain performance

Water Mist Fire Shutters

In recent years, a new type of fire-resistant roller shutter with innovative design, simple structure, and evident effectiveness has emerged domestically—the "Mist Fire-Resistant Roller Shutter" [Patent No.: 9822962.5]. This shutter consists of a single-leaf steel fire-resistant roller shutter, a water pipe with uniformly installed mist spray nozzles on one side of the transmission device, and a control system. It retains the advantages of the single-leaf steel fire-resistant roller shutter, cooling the curtain surface with mist, ensuring that the backside temperature of the curtain remains below 100°C within the fire resistance limit of 3 hours. This enables the fire-resistant roller shutter to replace firewalls in terms of insulation capacity, making it a product with strong vitality.

Water mist fire curtains also feature the following characteristics:

Maximize the heat absorption and latent heat of vaporization of water to achieve significant cooling effects on the curtain surface.

Water at a certain pressure (0.25~0.4 MPa) is atomized into tiny droplets of about 0.1 mm in diameter through a "tangential vortex" nozzle, directed towards the curtain surface. Due to the increased specific surface area of the water, it absorbs heat rapidly and evaporates quickly (the latent heat of vaporization of water is approximately 2700 kcal/kg), quickly removing heat from the curtain surface. Minimal excess water drips down, also reducing water damage losses after fire extinguishing.

② Low water jet strength

After numerous tests and inspections, the "mist spray" water spray intensity is approximately 0.101~0.125 L/s.m, which is 1/8-1/10 of the water spray intensity for an automatic sprinkler system installed on both sides of a standard fire curtain. This provides an economical and practical fire separation for larger spaces. As illustrated in Section 2.1 of this article, by setting a mist spray特级 fire curtain around the escalator, the water consumption for fire protection in a unit time is only 6.2L/s~7.8L/s. This approach, using fire hydrant water sources and leveraging the remaining balance of the original fire protection water supply, or selecting a larger-sized fire pump appropriately, can address the issue with cost savings and significant economic benefits.

③ Effective in eliminating fire smoke

Water mist effectively eliminates smoke and reduces environmental temperature, creating an excellent personnel evacuation environment within the mist range. It keeps individuals alert, with unobstructed breathing and good vision, thereby reducing fire-related casualties.

④ Steam effectively protects the drive mechanism of fire-resistant roller shutters

During the fire, the smoke curtain is enveloped by steam above, which blocks the combustion and protects the electrical transmission equipment from normal operation within the fire-resistant limit time.