WO2014001457A2

WO2014001457A2 - Modular water mist sprayer

Info

Publication number: WO2014001457A2
Application number: PCT/EP2013/063515
Authority: WO
Inventors: Carsten Palle
Original assignee: Vid Fire-Kill Aps
Priority date: 2012-06-28
Filing date: 2013-06-27
Publication date: 2014-01-03
Also published as: WO2014001457A3; DK177630B1

Abstract

The invention concerns a sprayer for production and distribution of fine water spray for fighting fires, where minimum 90% of the distributed water is distributed in form of water droplets having nominal droplet diameters less than 0,001m. The sprayer is characterized by comprising a body having inlet and outlet openings to an arrangement of multiple internal cavities which are in fluid connection with each other via one or multiple openings or channels between the individual cavities, and where one or multiple openings in the body surface together cover the circular periphery of the sprayer body, and where there is an opening at the body which hydraulically connects a swivel cavity in the body to the surroundings outside the body, and where the hydraulic connection to the swivel cavity consists of one or more openings/channels having centre lines which are not in parallel with the centerline of the swivel cavity.

Description

Modular water mist sprayer

Technical field:

The sprayer described herein may be used in fire suppression systems for fixed installation on on-shore, maritime and off-shore installations of high, and medium and low fire hazards. Embodiments of the sprayer are in particular applied for fire protection in locations with low water supply and drainage capacities and locations having limited power supplies and locations sensitive to damages from fire suppression water spray and pollutions from fire suppression water.

Background:

Fire protection with water from fixedly installed fire sprinkler systems is a known technology.

Fire sprinkler systems fight fires by distribution of water droplet sprays which consist of water droplets with nominal droplet size diameters of 0,001 - 0,005 meters, which make fire sprinkler systems fight fires primarily by the water droplets penetrating the fire plums to wet and cool the surface of the burning materials, and by hereby reducing the pyrolysis process, which due to the heat of the fires break down the fuel materials into flammable pyrolysis gasses, which merge with the oxygen in the surrounding atmosphere in the oxygenate processes which deliver the heat energy to the pyrolysis processes and combustion gasses and energy surplus.

A problem with the prior art fire sprinkler technology is that fire sprinkler systems require relatively large water densities to be distributed for the systems to be capable of fighting fires effectively.

The large water densities require locations with sprinkler systems to have large water supply and water drainage capacities, and sprinkler systems risk causing water damages and pollution from polluted sprinkler water, also cooling of fuel surfaces are most effective where sprinkler water can accumulate on the fuel surfaces, which is not the case for gas and hydrocarbon fires, where the fuel has a lower density than that of water.

A known method to solve the above problems has been to distribute sprays of water in the form of water mist, where minimum 90% of the water distributed is distributed as water droplets with nominal droplet diameters less than 0,001m.

Here the large surfaces compared to the little water volume of the droplets, causes heat of fires to heat the water fast, and the water in the water mist droplets to change phase from liquid H20 to H20 gas (steam). This phase transformation requires 47000 joules per mole of water, and all energy is taken from surplus energy of the oxygenate processes of fires, which cools the chemical processes of fires and reduces the pyrolysis processes and the oxygenate processes, and the steam and the cooled combustion gasses also reduces the oxygen concentration in the locations of the oxygenate processes, which further reduces the heat output of the oxygenate process, all causing suppression of fires, without cooling of fuel surfaces being the dominant extinguishing method.

A known method to produce and distribute water mist is to form a thin water jet with high velocity of the water, and to let the water jet hit the air in the surrounding atmosphere, and to use the kinetic energy of the water to split the water jet into a spray of water mist droplets against the air. The thinner the water jet is, and the higher the water velocity is, the smaller the water mist droplets become.

A problem with this method, which commonly is called "High Pressure Water Mist" is that the orifices need to be very small with diameters of 0,0001m to 0,0001m. This makes the nozzles to become very sensitive to clogging from impurities in the supplied water. This problem is commonly tried solved by filtrating water through very fine filters, and by designing all piping and water supply systems in high grade stainless steel and other non corrosive materials.

Another problem with "high Pressure Water Mist" systems is that the nozzles require water supplies which supply water to the nozzles at very high pressures, typically 50 bars to 200 bars. This problem is commonly tried solved by the use of high pressure water pumps and high pressure water piping, fittings and pipe system components, all adding costs to "High Pressure Water Mist" Systems and limiting the use of commonly available pipe system components for "High Pressure Water Mist" Systems.

A third problem with "High Pressure Water Mist" nozzles is that each water mist nozzle only provides a very small coverage area of water mist spray. This problem has been solved by locating multiple "High Pressure Water Mist Nozzles" on a nozzle manifold, and to locate the nozzles around the circular surface of the manifold together to provide water mist spray 360 degree around the "High Pressure Water Mist Sprayer". The many nozzles make the sprayer complicated to produce, and it provides an uneven water flux distribution of the water mist spray from the sprayer.

The above problem with "High Pressure Water Mist" systems has been tried solved with the "Low Pressure Water Mist". A commonly know method to produce water mist sprays from relatively low water pressures is the "Water Jet Impingement Method". Here two or more thin water jets are brought to collide in the atmosphere surrounding the sprayer. In the collision the kinetic energy of the water jets transforms the water jets into a spray of water mist droplets. A problem with this method is that the orifices need to be very small to produce the very thin water jets and that the orifices therefore become sensitive to clogging from impurities in the water supply. Another problem is that the orifices needs to be very accurately located for the water jets to collide accurately to transform all the kinetic energies of the water jets evenly to the collision in the order to produce a water mist spray having homogeneous droplet sizes and water distribution. Another problem with the "water Jet Impingement Method" is that most of the kinetic energy disappears, making the sprayers have very little coverage areas away from the sprayers. This problem has been tried solved by locating multiple water jet impingement points around the sprayer in order to cover a larger area around the sprayer with multiple water mist generators on the sprayer.

The problem with risk of nozzle clogging has been tried solved with the "deflector impingement style Low pressure Water Mist Nozzle" concept. I n this design a water jet hits a mechanical deflector surface. The core of the water jet deflects into water droplets on the deflector plate, and the water in the rest of the water jet collides with the deflected water, allowing the kinetic energy of the water jet to split the water jet in to a spray of water mist.

A problem with the "deflector impingement style Low Pressure Water Mist" concept is that the water jet and the deflector surface need to be very accurately located relatively to each other, for the sprayer to be able to make a homogeneous spray pattern with homogeneous water mist droplet sizes and water flux, making " Deflector I mpingement Style Low Pressure Water Mist" sprayers become very sensitive to mechanical impacts, and difficult to manufacture water mist sprays supplying reproducible water mist distributions and water fluxes. Another problem with

"Deflector impingement style Low Pressure Water Mist" sprayers is that the water mist spray from the deflector plate becomes shielded by the system fixating the deflector plate, and that this causes the sprayers to have un-even spray patterns. Another problem with the "deflector impingement style Low Pressure Water Mist" concept is to make sprayers have large coverage areas. This problem has been tried_solved by designing sprayers with multiple orifices and deflectors to cover areas around sprayers, and to combine "deflector impingement style" nozzle with a circular deflector nozzle, where the deflector impingement style nozzle is located below a deflector plate on a sprayer, and where the water to the deflector plate sprayer are taken to the deflector impingement nozzle opening through a stem holding the deflector impingement nozzle and the deflector below the deflector plate.

Summary of the invention:

The invention provides a more industrial solution the described problems. The new invention concerns a sprayer for fire fighting with water mist spray, comprising a body having a series of two or more internal cavities which are fluidly connected in series via respective one or multiple channels/openings, and where the outer sprayer body surface has one or multiple inlet openings into the first cavity of the series of internal cavities, and where in the cavity wall of one or more of the cavities are provided one or multiple slot-shaped openings to the outside of the sprayer body, and where the last cavity in the series of cavities inside the sprayer body is connected to the second to last cavity with one or multiple channels/openings, where one or more of the channels/openings has a centerline which meets the cavity wall of the last cavity in at least partially tangential direction (i.e. where the centerline forms an acute angle with the tangential direction of the cavity wall), and where there in the end cavity wall of the last cavity in the series of cavities is an opening from the cavity space to the free outside of the sprayer body. In one embodiment, the sprayer is provided as a single component forming the sprayer body and defining the cavities therein.

The sprayer may be installed so that pressurized water from a water supply of more than 2 bars is allowed to flow through the openings into the first cavity in the series of cavities in the sprayer body. The cavity is filled with water, and water flows through the openings to the next cavity of the series inside the sprayer body, the water flows hereafter through the series of hydraulically connected cavities in the sprayer body. In cavities having one or multiple slot-like openings in the cavity wall to the outside of the body, water flows through the opening from which water is distributed as a thin water film in the whole angle of the slot. The shaped area which each water film covers expands like the area of a fan with increasing distance to the opening, this stretches the water film and causes the film to be come thinner until the water film collapses into a water mist spray at a distance to the opening, thus making the sprayer cover a large area around the sprayer body with water mist spray. The sprayer has one or multiple openings which together form thin water films surrounding the sprayer body. When water flows into the last cavity in the series of cavities in the sprayer body, some or all of the water passes through one or multiple openings which direct the water in a tangential direction to the circular cavity wall, to make the water swivel in the same direction inside the last cavity in the series of cavities in the sprayer body. This way the water swivels around with high velocities in the last cavity of the series of cavities inside the sprayer body. The water hereafter exits the series of cavities through an opening in the end wall of the last cavity. Here the centrifugal force of the swivel effect forces the water radially away from the opening in all directions as small droplets having high velocities. The droplets collide with the atmosphere outside the exit opening and the kinetic energy of the droplets causes the droplets to split up into a fine water mist spray, which covers the areas below the sprayer body and fills the space with a dense water mist spray. The water mist spray coming from the side of the sprayer body and the water mist spray from the end opening create locally draft conditions which makes the water mist sprays from the side of the sprayer merge with the water mist spray from the opening into the last cavity into a homogeneous fine water mist spray which covers a large volume below the sprayer body with a dense water mist.

In some embodiments, the opening from the last body cavity to the outside of the sprayer body is circular with an increasing diameter from the cavity towards the outer surface of the body.

In this embodiment the swiveling water flow exiting the last cavity of the sprayer body follows the surface of the exit opening. By forming the exit opening with increasing diameters, e.g. conically, as for example the shape of a trumpets outlet, the spray angle increases, to increase the volume and foot print area of water mist coverage from the outlet opening below the sprayer body.

In another embodiment, one or multiple openings between the last and the second last cavity in the series of cavities internally in the sprayer body each has a diameter between 0.002 to 0.003mm.

The openings limit the water flow to the swivel chamber, thus allowing the water to swivel with high velocities in the swivel chamber, and to exit the swivel chamber of the sprayer nozzle with high velocities, producing a fine water spray of droplets with minimum 90% of the water distributed in droplet with nominal diameters being less than 0,001m. This embodiment also allows the sprayer nozzle to have orifices with openings having a cross-sectional area which can be up to 100 times larger than the nominal drop sizes of the distributed water.

In yet another embodiment the last cavity in the series of cavities has a circular cross- section, and where the centre line of one or multiple openings connecting the last cavity to the second last cavity in the series of internal cavities in the sprayer body meets the tangent to the circular last cavity in an acute angle which are from 0-45 degree.

A circularly shaped swivel cavity provides little resistance for water to flow along the cavity surface, thus allowing high water velocities in circular swivel chambers at low water input effects. Supplying water to the swivel chamber in angles which are close to the circular surface tangent optimizes the water swivel velocities in the swivel capacity. The smaller the angle is the more of the kinetic energy from the supplied water are used to swivel the water around in the swivel chamber, and the faster the water velocity becomes. The sprayer body may have rotationally symmetric, e.g. cylindrical, shape having an inlet end and an outlet end, where the inlet opening is located at the inlet end and the outlet opening located at the outlet end. The slot-shaped openings are arranged around the circumference of the cylinder such that the slot-shaped openings along the entire circumference. The slot-shaped openings may be displaced from each other in the axial direction. Each slot is elongated in the circumferential direction.

In yet another embodiment the sprayer body has a rotationally symmetric, e.g.

cylindrical, shape, and the angles of slot shaped openings together cover the whole circular periphery surrounding the sprayer body. The slot-shaped openings may each have a width of 0,0005m to 0,002m. The slot-shaped openings may be directed in a radial direction relative to a centerline of the sprayer body. Alternatively they may be directed upwards or downwards, i.e. the centerline of the slot-shaped openings may be oriented at an angle of 0- 45 degrees relative to the centerline of the sprayer body.

A circular rotation symmetrical sprayer body is simple to manufacture, and easy to apply with threads and seals, and to fixture, and to apply with slot openings. One or multiple slot openings connecting the sprayer body surfaces to one or multiple internal cavities, allows the sprayer to distribute fine water spray around the sprayer body, and slot angles of 0-45 degrees to the sprayer body, prevent the water sprayed for collecting on the sprayer body to form large water droplets, and slot open width of 0.0005m to 0.002 m make the slot openings form water film thicknesses which later can break down into water mist sprays, and yet be little sensitive to impurities in the water supply.

In yet another embodiment, the sprayer body has an end portion at the end opposite the outlet opening, where the end portion has an enlarged cross sectional area.

An enlarged cross section end allows the sprayer body to be fixed in fixtures for example cone or flange fixtures, where the sprayer body from the opening to the swivel cavity to the enlarged cross section on the sprayer body are located outside a hole in a flange or cone fitting, and the enlarged cross section of the sprayer body holds the sprayer body in a cone or shoulder surface, and prevents the water supply pressure from pressing the sprayer body out through the hole fixating the sprayer body, and it allows hydraulic leak proof joints to the sprayer body, finally it allows the sprayer body to be used as a sprayer cartridge, which can mode inside a housing without falling out of the housing.

In yet another embodiment the outside surface of the sprayer body is formed with a thread for connecting the sprayer body to a threaded water supply port. A pipe connection in the form of a pipe thread in the sprayer end having one or multiple inlet ports to the first cavity in the internal series of cavities allows the sprayer body to be installed directly in the water supply pipes.

In yet another embodiment the sprayer body in the one end forms a hydraulic seal.

The variation allows that the sprayer body can form a leak proof plug in the water inlet to a housing which holds the sprayer body fixated.

In yet another embodiment the sprayer body has the shape of a shaft cartridge in a low pressure water mist sprinkler having automatic heat release from heat of fire.

Here the sprayer is located in a housing, which in the one end is connected to a water supply, a in the other end holds a support fixed with a heat sensitive element on which the end of the sprayer body having an opening into the swivel cavity rests. In housings where the support does not seal the housing, the sprayer body is shaped to provide a seal into the housing at its end opposite the support. In this embodiment the heat sensitive element releases to release the support, the supply water pressure supplies a pushing force on the sprayer body, which presses the sprayer body out of the housing opening until the sprayer body cannot move any more, and water hereafter flows into the series of cavities in the sprayer body, which produces water mist sprays and distributes the water mist spray to the sides and below the sprayer body.

In yet another embodiment the heat release element fixating the support is electrically released from ether resistance heating or from electrical activated mechanical impact.

Brief description of the drawings:

Figure 1 shows a schematic view of an example of a sprayer with a hydraulically interconnected series of cavities including a first cavity with a 360 degree slot opening and a swivel cavity.

Figure 2 shows a schematic top down view of an example of hydraulic connection openings between the two last cavities in the series of cavities in the sprayer example of figure 1.

Figure 3 shows the water flow in the sprayer example shown in figure 1 and figure 2.

Figure 4 shows an example on a sprayer having multiple slot openings into the series of internal cavities in the sprayer body.

Figure 5 shows an example of a sprayer with a threaded connecting for direct installation in water supply pipe work. Figure 6 shows an example on a sprayer formed as a cartridge having a cone shaped end, and which is installed in a housing having an automatic heat release from fires, and where the end of the sprayer forms a seal in the water inlet of the housing.

Figure 7 shows an example on a sprayer formed as a cartridge with a cone shaped end, which is installed in a housing having automatic heat release from fires and electrical resistance heat activation of the heat sensitive release element.

Examples

Figure 1 shows and example on a sprayer having a water inlet (8) with a strainer (9) to protect the sprayer cavities and openings and orifices against impurities in the water supply. The sprayer body (1) of this example consists of two parts (la & lb) which are held together to form a series of cavities (3) & (6), which are hydraulically connected with each other by openings(channels ( 5a &5b), and where the water inlet port (8) is hydraulically connected to the series of cavities with openings (2a & 2b), and where one of the cavities (3) has a slot-shaped opening (4) which provides a 360 degree opening to the surrounding of the sprayer, and where the centerline of one or more of the hydraulic connection openings (5a &5b) to the last cavity (6) in the series of cavities hits the cavity (6) walls at least partially tangentially to the surfaces. Hence, the centerline defines a direction having a component tangentially to the cavity surface at the position where the centerline intersects the cavity surface. The last cavity comprises a centrally located opening (7) in the end wall of the last cavity (6) in the series of hydraulic connected cavities in the sprayer body (la & lb).

Figure 2 shows a detail of an example of a sprayer viewed from the end surface (1) of the second last cavity in the series of cavities, where the hydraulic connection between the two last cavities in the series of cavities consists of two openings/channels (2A & 2B) each opening/channel having a water inlet (3a) & (3b) and a water outlet (4a) & (4b) and a centerline (5a) & (5b), and where the centerline of at least the one hydraulic connection opening hits the cavity surface wall of the last cavity in the series of cavities (6) in a tangential angle 7, which causes water flowing through the opening to flow in one direction along the cavity wall (6), and where the centerlines of other hydraulic connection openings to the last cavity have a direction which causes water to flow against the each other along the cavity surface of the last cavity of the cavity series in the sprayer body.

Figure 3 shows the function of an example of sprayer. Water from the water supply having a water pressure of 2bars to 20 bars (1) flows through the strainer (2) in the inlet of the sprayer and through the inlet opening (3) into the first cavity (4) of the series of cavities in the sprayer. The water pressure presses water through the slot opening in the cavity wall and produces a thin film of water (5) which surrounds the sprayer, and which collapses into a water mist spray as the film stretches and collapses.

The water flow in the cavity (4) also presses water through the hydraulic connection opening to the next cavity in the series of cavities. The hydraulic connection (6) connecting the last cavity (7) to the second to last cavity (4) in the series of cavities has one or multiple opening centerlines angled to the surface of the cavity, which makes the water flowing into the last cavity (7) to swivel along the wall of the cavity. The water velocity increases with the effect from water supplied to the cavity. The water pressure in the cavity (7) presses the swiveling water out through an opening (8) at the end wall of the cavity. From here the rotation velocity of the water drives the water in all directions below the opening, and the high velocities causes the water to break up into a fine water mist spray.

Figure 4 shows an example on a sprayer variation, consisting of a body (1) with a water inlet (2) with a filter (3), which is hydraulically connected to a cavity (4) with multiple slot openings (5a, 5b, 5c) in the cavity wall, and which together cover a 360 degree circle. The cavity (4) has openings (6a) and (6b) in the end wall surface of the cavity, which hydraulically connect the cavity to another cavity with minimum one opening (6a) that has a centerline which is at least partially tangential to the surface of the cavity, and where one opening (6b) has its center line pointing towards a centrally located opening (8) at the end of the last cavity in the series of cavities making a swivel chamber in the sprayer body.

When pressurized water flows from the water supply through the water inlet (2) and the filter (3) into the cavity (4), a water pressure builds up in the cavity (4), which presses water out through the slot openings (5a&5b&5c) in the cavity wall, thus forming a thin water film surrounding the sprayer body in 360 degree, and the water pressure also presses water to flow from the openings (6a) in the cavity back wall (6b). The water flows through an opening (6a) having its centerline located tangential to the cavity wall of the last cavity (7) in the series of cavities in the sprayer body, which makes the water in the cavity (7) swivel around in the cavity and the water pressure in the cavity (7) to press the swiveling water out through an opening which are centrally located on the back wall of the cavity. The water flow through the sprayer is limited by the size of the center opening (7), A large opening risks causing the sprayer to produce a hollow spray pattern below the sprayer. This may be helped by having a centrally located opening (6b) to deliver a water flow directly into the central opening (8).

Figure 5 shows an example on a sprayer where the sprayer body is threaded at the end where the sprayer has the water inlet port. When pressurized water flows from the water supply into the nozzle pipe, the pipe wall (4) contains the pressurized water in the pipe cavity (5), from here the pressurized water flows into the water inlet port (6) of the sprayer body (1), and from here through the sprayer strainer (7) into the inlet cavity (8) and through the openings (9) into the a cavity (10) with slot openings in the cavity wall (11) from where water is distributed as a thin water film around the sprayer body, and water flows through one or multiple openings having the centerline meeting the surface of the following cavity tangential to the surface, and where the flow of water makes the water swivel around in the cavity (13), and where the cavity has a centrally located opening (14) to free from where water is distributed as a water mist spray of water droplets.

Figure 6 shows an example on an automatic arrangement for installation in pipe systems which are pressurized with a gas or a fluid. The figure shows a sprayer (1) which is located in a cavity (2) inside a housing (3) with a threaded connection (4) for hydraulic connection to pressurized water supply pipes, and where the sprayer body at the one end rests on a support (8), with a protection shield (10) attached, and which is fixated with one or multiple locks (9) which are kept in place with a heat sensitive release element (10), and where the other end of the sprayer body forms a plug (6) with a seal (7) which seals the water inlet port (5) of the housing and prevents pressurized water from entering into the cavity (2) of the housing and hereby preventing the housing from leaking or, if the support (8) is a leak proof fixture to the housing (3), it prevents a higher hydraulic force from acting on the support, due to the large support area.

In case of a fire in the vicinity of the arrangement, the heat of fire will cause the heat sensitive element (11) to disintegrate, and the lock to fall away, allowing the gas or hydraulic pressure in the inlet port (5) to push the sprayer body (1) down into the housing cavity (2) pushing the support (8) away, and falling out of the cavity until a smaller hole cross section area stops a larger cross section area at the end of the sprayer body, and inhibits the sprayer body from exiting the housing cavity, and forms a seal between the sprayer body and the housing cavity. This makes the plug (6) exiting the water inlet port of the housing, allowing pressurized gasses or liquids to flow through the house inlet port (5) into the housing cavity (2), through the inlet opening in the sprayer body (12), and into the series of cavities in the sprayer body (13), out through the slot openings (14) through openings (7) connection the swivel cavity to the series of sprayer cavities, and out through the central opening in the swivel cavity.

Figure 7 shows an example of an arrangement where a variant of the sprayer where the sprayed is a part of an arrangement for individual activation of water mist spray from the sprayer which is caused from heat of fire in the vicinity of the arrangement and from an electrical power signal. The example consists of an arrangement (1) which is described in figure 6, where an electrical resistance heat element (3) in the shape of for example a metal thread is placed in the vicinity of the heat release element (2) and where the resistance heat element is connected to terminals (4) which are located on the protection plate (5).

In case of fire the heat release element either activate from heat of fire or from electric resistance heat.

Claims

1. A sprayer for fire fighting with water mist spray, comprising a sprayer body defining a series of two or more internal cavities which are connected with one another in series by respective one or multiple openings or channels, and where the sprayer body has one or multiple inlet openings into the first cavity of the series of internal cavities, and where the cavity wall of one or more of the cavities is provided with one or multiple slot-shaped openings providing a fluid communication between said one or more cavities and the space surrounding the sprayer body, and where the last cavity in the series of cavities is connected to the second to last cavity by one or multiple openings or channels, where one or more of said openings or channels has a centerline which meets the cavity wall of the last cavity in the series of cavities in an at least partially tangential direction, and where an end wall of the last cavity in the series of cavities comprises an opening from the cavity to the space surrounding the sprayer body.

2. A sprayer in accordance with Claim 1 wherein the opening from the last body cavity to the space surrounding the sprayer body is circular with an increasing diameter.

3. A sprayer in accordance with Claim 1 or 2, wherein one or multiple openings or channels between the last and the second to last cavity in the series of cavities of the sprayer body each have a diameter between 0,002mm and 0.003mm.

4. A sprayer in accordance with any one of the preceding claims, wherein the last cavity in the series of cavities has a circular cross section, and where the centre line of one or multiple openings or channels connecting the last cavity to the second last cavity in the series of internal cavities intersects with a tangent to the circular last cavity at an angle between 0-45 degrees.

5. A sprayer in accordance with any one of the preceding claims, wherein the sprayer body has a rotationally symmetrical shape, and the angular extent of the slot-shaped openings together cover the whole circular area surrounding the sprayer body, and where the slot-shaped openings each have a width of 0,0005m to 0,002m, and where the centerline of the slot shaped openings have an angle of 0- 45 degrees to a centerline of the sprayer body.

6. A sprayer in accordance with any one of the preceding claims, wherein the sprayer body at the end opposite the outlet opening of surface has an enlarged cross-sectional area.

7. A sprayer in accordance with any one of the preceding claims, wherein at least a portion of the outside surface of the sprayer body is formed with a thread for connecting the sprayer body to a threaded water supply port.

8. A sprayer in accordance with any one of the preceding claims, wherein the sprayer in the one end forms a hydraulic seal.

9. A sprayer in accordance with any one of the preceding claims, wherein the sprayer body has the shape of a shaft cartridge in a low pressure water mist sprinkler having automatic heat release from heat of fire.

10. A sprayer in accordance with any one of the preceding claims, wherein the sprayer body has the shape of a cartridge which is located in a housing having a heat release element, and an electrical resistance heat element.