DESCRIPTION

MULTI IMPACT TYPE WATER MIST NOZZLE FIELD OF THE INVENTION

The present invention is directed to a novel design of atomization devise or nozzle. It refers to a type of nralti impact water mist nozzle.

BACKGROUND OF THE INVENTION

According to different classification standards ^{" "} such as the theory of water mist generation, pressure of the water mist generation etc, water mist nozzle has different classification ways.

The theories of water mist generation are normally classified. as direst or diffuser impingement, pressure jet, gas atomizing, and jet interaction.

The operation theory of diffuser impingement nozzles is by hitting a relatively stable coherent water jet against a diffused The diffuser breaks the stream into a high momentum mist with largest rang of droplets diameters compared to other types water mist nozzles. 90% of the droplets diameters are smaller than 600 microns. The operating pressures of the impingement nozzles are about 7 bar to 17 bar. For fire protection applications, impingement nozzles can be closed end automatic releasing or open end deluge type for total flooding and local protection. According to existing reference, the diffuser designs of the impingement nozzles include multi slots type, spherical type and spiral type. In the field of fire protection application, a closed end automatic releasing, multi slot type impingement water mist nozzle is disclosed in US Pat. No.5, 392,993. A open end spherical type impingement water mist nozzle is disclosed in US Pat. Np. 5,505,383. Comparatively, the spiral type nozzle has potential risk to operator during installation and maintenance.

Pressure jet water mist nozzles operated by. discharging high velocity water streams of water through a number of very small, orifices. These systems typically employ a ^" swSfing action device within the chambers or nozzles to help break up the water streams. . The operating pressure of the pressure jet water mist nozzle is within the range of 5 to 280 bar. The droplets diameters 90% smaller than 150 microns. For fire protection application, in US Pat. No. 5,513,708 disclosed a automatic releasing water jet watermisrnozzle. In International Pat. No, WO93/00962 disclosed a open type pressure jet water mist nozzle.-

Gas-atomizing water mist nozzles or named ^' twin-fluid nozzles, water mist is generated by combing compressed gas with water in a mixing chamber located just upstream of the discharging orifices. The operating pressure of the gas-atomizing nozzles is about 5 bar. The droplets diameters are 90% smaller than 250 micron. As to ensure the water pressure and gas pressure in the nozzle paths reach the mixing

requirement. Therefore, there is only open type gas-atomizing water mist nozzle which is limited in local protection and total flooding protection. In the field fire protection, US Pat No. 2,361,144 and US Pat. No. 5,014,790 disclosed two types of gas-atomizing water mist nozzles.

Jet interaction water mist nozzles use multiple pairs of fine fluid jets colliding with each other at certain angles to break up the fluid stream and form water droplets. The operating pressure of the jet interaction water mist nozzles are about between 3 to 7 bar. Since the momentum of the mist generated by jet interaction water mist nozzles is relatively low. So applications of jet interaction water mist nozzles are limited to manual hose nozzle for extinguishing low volatility flammable liquid fire by cooling and dilution. In US Pat No. 2,310,798 and US Pat No. 2,493,982 disclosed two designs of jet interaction water mist nozzle.

SUMMARY OF THE INVENTION

The objective of the present invention is to provide a _. novel design of water mist nozzle which is low cost, simple installation, and wide operation range. The invented water mist nozzle can be open end design and closed end design with temperature controlling function. Especially, with multi impact, the water mist is comparatively denser and finer.

The invention is achieved by:

A multi impact type water mist nozzle, which include a body, impact needles, along axis of the body from top downward, it is the water inlet, the main channel, the branch channels. The number of outlets of the branch channels is same as the number of the impact needles. The impact needles are in U shape, and they are evenly distributed and are coaxial with the axis of the body. One end of the U shape impact needle is fixed end which stamped at rim of the lower surface of the body. Other end of the impact needle is the impact surface, which is facing and perpendicular to the axis of the branch channel, characterized in that the outlets of the branch channels are evenly distributed on the inner and outer deflective rings. The inner and outer deflective rings are coaxial to the axis of the body and adhered together. The deflective angles of the inner and outer deflective rings are not equal.

The multi impact type water mist nozzle also includes a temperature control device. The temperature control device is located inside the main channel and coaxial with the body. From the top downward includes sealing ring, valve body, glass bulb and valve cover. The valve body is fixed in position by the sealing ring at the top and the glass bulb at the bottom.. The glass bulb is supported by the inner central surface of valve cover at the bottom. The valve cover is located lower than the branch channels and connected to the body by screw thread. It forms a closed end device for the water mist nozzle.

The inner deflective ring is with inner angle (A), which is smaller than the inner angle (B) of the outer deflective ring. Firstly, water mist stream is generated when water comes out from the branch channel outlets and impacts on the impact needles. Secondly, water mist streams from the inner deflective ring impact against the water mist streams from the outer deflective ring. It generates more evenly distributed, denser and finer water mist. The angles (A) and (B) are between 60 to 120 degrees.

The impact needle is with circular cross section and with diameter smaller that the diameter of the branch channel outlet. The mentioned branch channel is with diameter between 1.0 to 2.5mm.

The impact surface of the impact needle is with distance lesser than 1 mm from the branch channel outlet.

The advantage of this invention is simple structure, convenient installation; it allows the diameter of the branch channel outlet to be selected for different applications, flow and quality of water. The number of branch channels is selected for different applications, flow and quality of water. According to applications, the nozzle can be open type or closed type with temperature control device. The special provision of multi impact of water mist stream by means of different deflective angles of the inner and outer deflective rings. Finer, denser and more evenly distributed water mist is generated. The invented open type nozzle can be applied in deluge type total flooding and local protection systems. The invented closed type nozzle can be applied in automatic releasing system. In the fire protection field, the multi impact water mist nozzle can suppress and extinguish Classes A, B,C and K fires. Other than fire protection, the multi impact water mist nozzle can be used in any applications which water mist is needed, such as area humidification, gas turbine cooling etc.

DETAIL DESCRIPTION OF THE DRAWINGS

There are two attached drawings for this invention, which are: Figure 1, drawing of the open end type multi impact type water mist nozzle; Figure 2, drawing of the closed end type multi impact type water mist nozzle. Legend: (1) Body, (2) Impact Needle, (2a) Impact Needle Fixing End, (3) Branch Channel, (3a) Branch Channel Outlet, (3b) Branch Channel Axis, (4) Main Channel, (5) Water Inlet, (6) Outer Deflective Ring, (7) Inner Deflective Ring, (10) Sealing Ring, (11) Valve Body, (12) Glass Bulb, (13) Valve Cover.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

EMBODIMENT 1. OPEN END TYPE MULTI IMPACT TYPE WATER MIST NOZZLE

As shown in figure 1, the multi impact type water mist nozzle includes the body (1) and impact needles (2). Along the axis of the body (1), from top downward; there are water inlet (5), main channel (4), branch channel (3). The number of the water outlets (3b) of the branch channels (3) is same as the number of the impact needle (2). The impact needle is in U shape and distributed evenly coaxially with the body (1) main axis. One end of the U shape impact needle (2) is the fixing end (2a), which is stamped on the rim of the lower surface of the body (1), other end is the impacting face which faces and is perpendicular to the axis of the branch channel (3). The outlets (3 a) of the branch channels are evenly distributed on the outer deflective ring (6) and inner deflective ring (7), which the two rings are adhered together with different deflective angles. The angle (A) of the inner deflective ring (7) is smaller than the angle (B) of the outer deflective ring. A is 90 degree and B is 120 degree. The impact needle has circular cross section and the diameter is not larger than the diameter of the branch channel outlet. The diameter of the branch channel outlet is 1.5mm. The distance between the impact surface of the impact needle and the branch channel outlet is smaller than lmm.

EMBODIMENT 2. CLOSED END TYPE MULTI IMPACT TYPE WATER MIST NOZZLE

As shown in figure 2,. the difference of this embodiment from embodiment 1 is the additional of temperature control device. The temperature control device located at the main channel (4), coaxial with the body (1), from top downward is the sealing ring (10), valve body (11), glass bulb (12) and valve cover (13). The valve body (11) is fixed in position by the sealing ring (10) at the top and the glass bulb (12) at the bottom.. The glass bulb (12) is supported by the inner central surface of valve cover (13) at the bottom. The valve cover (13) is located lower than the branch channels (3) and connected to the body (1) by screw thread. It forms a closed end device for the water mist nozzle. The closed end water mist nozzle has the temperature control devise, the nozzle will open at definite temperature.