SPRAY NOZZLE UNIT

Abstract

The invention relates to a spray nozzle unit, in particular for spraying explosion risk areas in subsurface mining, and for use in ultra high speed fire suppression system at response times below 50 milliseconds, having a nozzle body. The nozzle body has a nozzle opening for ejecting spray liquid, allowing low water consumption, designed robustly, and allowing operation without compressed air. A closing means is disposed in the nozzle body for closing the nozzle opening in the non-pressurized state of the spray nozzle unit.

Description

The present invention proposes a spray nozzle unit for spraying heavily dust-laden areas as well as potentially explosive areas in underground mining, with a nozzle body that exhibits a nozzle opening for ejecting spray liquid.

PRIOR ART

Various methods are used for finely spraying liquids at a low water consumption level.

1. Fine spray nozzles with very small bore diameters, e.g., 1 mm, which are operated at high pressures ranging between 50 and 200 bar.

2. Two-component nozzles that use compressed air to finely atomize the liquids.

The disadvantages include a potential jamming of nozzles on the one hand, and the necessity for compressed air on the other, which are associated with significant drawbacks, in particular in underground mining.

Known from DE 198 51 620 A1 is a generic spray nozzle unit. Spray nozzle units are used in particular for spraying potentially explosive areas in underground mining, and a plurality of spray nozzle units can be accommodated on a nozzle receptacle of a spraying system, for example so as to spray the cutting area of the selective cut heading machine with water underground. In order to spray the cutting area as comprehensively as possible, it can be provided that highly pressurized compressed air be added to the supplied water to ensure that the water is effectively atomized, wherein the necessary water consumption is reduced at the same time. However, the disadvantage to using atomizing nozzles is that compressed air with high pressure values must be provided to atomize the added water.

By contrast, spray nozzle units that do not need compressed air and are operated at high water pressures lead to high water consumption. If the diameter of the nozzle opening is diminished to reduce water consumption, a high water pressure is necessary, which requires an intricate process to prepare.

Given the harsh conditions under which such spray nozzle units are used underground, in particular in direct proximity to the cutting area of a selective cut heading machine, the spray nozzle unit must be furnished with an appropriately robust design. Contaminants can penetrate into the nozzle opening and end up jamming the spray nozzle unit, so that the cutting area of a selective cut heading machine might no longer be reliably sprayed. The machine operator is basically unable to see the area in which the spray nozzle units are arranged in a nozzle receptacle of a spraying system. This makes it difficult to oversee the process of monitoring a spraying system to verify smooth operation. Therefore, a nozzle unit having an especially robust design is desirable.

OBJECT OF THE INVENTION

As a consequence, the object of the present invention is to provide a spray nozzle unit that overcomes the disadvantages to the prior art described above, and enables low water consumption. Further, the object of the present invention is to provide a spray nozzle unit having a robust design. Finally, the object of the present invention is to provide a spray nozzle unit with a low water consumption that enables compressed air-free operation, and is suitable for use in ultra high speed fire suppression systems at response times of below 50 milliseconds.

This object is achieved based on a spray nozzle unit according to the preamble to claim 1 in conjunction with its characterizing features. Practical further developments of the invention are indicated in the dependent claims.

DISCLOSURE OF THE INVENTION

The invention encompasses the technical instruction that the nozzle body incorporates a closing means that closes the nozzle opening with the spray nozzle unit in an unpressurized state.

The advantage achieved by arranging a closing means in the nozzle body is that the nozzle opening can then be closed by the closing means when the spray nozzle unit is not in operation, i.e., the spray nozzle unit is not pressurized, and thus at zero pressure. No contaminants can get into the nozzle opening with the spray nozzle unit operational, since the exiting spray liquid, in particular water, prevents contaminants from penetrating into the nozzle opening. If the spray nozzle unit is not operational, the closing means according to the invention prevents contaminants from entering the nozzle opening. As a result, contaminants are prevented from penetrating into the nozzle opening, regardless of the operating state of the spray nozzle unit. Arranging the closing means in the nozzle body itself protects the closing means against mechanical influences, and the nozzle body of the spray nozzle unit can be given the conventional outside design.

It is especially advantageous that the closing means be designed as a clamping piston, which preferably is reciprocatingly incorporated in the nozzle body along a central axis of the nozzle body. The nozzle body can essentially have a rotationally symmetrical configuration, basically giving it roughly cylindrical shape. The rotational axis of the cylindrical nozzle body forms the central axis, wherein the clamping piston is also rotationally symmetrical. As a consequence, the clamping piston can be guided back and forth between a closed position and open position along the central axis, wherein the clamping piston closes the nozzle opening in the closed position, and releases it in the open position.

It is especially advantageous that the closing means be able to reciprocate between a closed position and open position along the central axis by pressurizing the spray nozzle unit with spray liquid. Pressurization with the spray liquid takes place in such a way that the closing means can be moved from the open position to the closed position. Once pressurization has ended, the closing means moves back into the closed position from the open position. As a consequence, neither a manually activated closing means nor an actuator is needed, since the closing means is advantageously arranged in the nozzle body in such a way that the reciprocating motion is caused solely by pressurization with the spray liquid.

The closing means advantageously exhibits a locking pin for at least partial immersion into the nozzle opening in its closed position. The locking pin can preferably exhibit an outer diameter roughly corresponding to the inner diameter of the nozzle opening. Therefore, the locking pin forms an extension on the closing means, and is also rotationally symmetrically arranged around the central axis of the nozzle body. If the closing means is moved toward the closed position, the locking pin dips into the nozzle opening, wherein the immersion depth preferably corresponds to at least the length of the nozzle opening toward the central axis. This reliably prevents contaminants, such as dust, cave material and the like from being able to get into the nozzle opening. The locking pin preferably exhibits a length at which the locking pin extends completely through the nozzle opening in the closed position, in particular closing off the nozzle body from outside.

It is further advantageous for the nozzle body to incorporate a pressure chamber movably bordered by the closing means. The pressure chamber can be pressurized with spray liquid, wherein the pressure chamber is preferably arranged in such a way that the closing means can be moved from the closed position to the open position by pressurizing the pressure chamber.

Having a partial area of the closing means movably border the pressure chamber causes the closing means to move in the nozzle body in such a way that the pressure chamber volume increases. As a result, the closing means can get from the closed position into the open position. It is further advantageous for the closing means designed as a clamping piston to exhibit at least one sealing element to make the pressure chamber pressure-tight. In particular, the sealing element dynamically seals the clamping piston against the interior wall of the nozzle body.

It is further advantageous to provide a spring element that spring preloads the closing means in the closed position. If the spray nozzle unit is not pressurized with spray liquid, it must be ensured that the closing means stays in the closed position. Only then does the locking pin extend through the nozzle opening, and contaminants are effectively prevented from penetrating into the nozzle opening. The spring element is preferably designed as a helical compression spring, and located on a side of the closing means opposite the arrangement of the pressure chamber bordering the closing means.

In another advantageous embodiment of the spray nozzle unit according to the invention, the closing means exhibits a feed channel through which the pressure chamber can be pressurized with spray liquid. The feed channel extends from one receiving side of the nozzle body until into the pressure chamber. At the same time, the receiving side of the nozzle body forms the side on which the spray nozzle unit is supplied with spray liquid, in particular water. As an alternative, the feed channel can also extend through the nozzle body in order to expose the pressure chamber to spray liquid.

The pressure chamber is advantageously fluidically connected with the nozzle opening, in particular when the closing means is released from the closed position. The spray liquid provided via the feed channel initially floods the pressure chamber, before the spray liquid gets from the pressure chamber into the nozzle opening, to then exit the spray nozzle unit again via the spray side of the nozzle body. As a consequence, the spray liquid is first used to move the closing means into the open position or keep the closing means in the open position, so as to then exit the spray nozzle unit via the nozzle opening for atomization. If the closing means is still in the closed position, the pressure chamber already has a starting volume. If the pressure chamber is pressurized with the closing means in the closed state, the pressure acts on the wall of the closing means bordering the pressure chamber, so that the closing means moves from the closed position into the open position. While the spray nozzle unit is in operation, the pressure of the spray liquid prevailing in the pressure chamber is high enough to keep the closing means in the open position.

It is basically possible to have the pressure chamber supplied only via a bypass, so that a portion, in particular most, of the spray liquid gets into the nozzle opening through the closing means via a primary channel. The portion of spray liquid passing into the pressure chamber via a bypass can be calculated in such a way that also makes it possible to keep the closing means in the open position.

In addition, the nozzle body can incorporate a low-pressure chamber movably bordered by the closing means on a side lying opposite the pressure chamber. Preferably situated in the nozzle body is a vent port that links the low-pressure chamber with the outside of the nozzle body. The vent port allows the low-pressure chamber to breathe, and when the closing means moves from the closed position into the open position, air can escape to the outside from the low-pressure chamber through the vent port. As the closing means moves back into the closed position, air flows through the vent port and back into the low-pressure chamber. In particular, the spring element can be situated in the low-pressure chamber to preload the closing means toward the closed position.

In another advantageous embodiment of the spray nozzle unit according to the invention, the pressure chamber empties like a funnel into the nozzle opening with the closing means in the open position, wherein the surfaces bordering the pressure chamber at least partially exhibit a helical structure that allows the spray liquid to exit the nozzle opening with an angular momentum. The surfaces of the helical structure involve in particular the surfaces adjacent to the nozzle opening, for example inside the nozzle body and/or at the front of the closing means. This causes the spray liquid to helically move around the central axis, so that the spray liquid can exit the nozzle opening with an angular momentum. As a result, an especially large spraying angle can be achieved, at which the spray liquid exits the nozzle opening. In a further advantage, the feed channel can empty into the pressure chamber in such a way as to already generate a rotation by the spray liquid around the central axis. The pressure chamber also extends around the central axis in a rotationally symmetrical manner, and a flow cross section tapering like a funnel toward the nozzle opening serves to intensify the twisting effect. As a result, a comparably large diameter of the nozzle opening can be used to finely atomize the spray liquid, in particular into small water droplets. The fluid pressure of the spray liquid can measure 4 bar to 8 bar, preferably 5 bar to 7 bar, and especially preferably 6 bar. A water system with 6 bar is routinely encountered in underground mining, so that no peripheral equipment must be provided to operate a spraying system at higher pressures.

It is especially advantageous for the nozzle opening to exhibit a diameter of 1 mm to 6 mm, preferably a diameter of 2 mm to 4 mm, and especially preferably a diameter of 3 mm. In particular, the locking pin can be situated adjacent to the nozzle opening in the open position. As a consequence, the locking pin can also extend at least partially into the nozzle opening with the closing means in the open position. An annular cross section can be formed in this way, as a result of which the spray liquid can be made to exit as a solid jet or even a hollow jet (the generation of a solid jet must here be regarded as an innovation). If a centrally present locking pin brings about an annular cross section in the nozzle opening, a hollow jet of spray liquid can be generated. In order to close the nozzle opening, the locking pin can be introduced so far into the nozzle opening that the latter completely runs through the nozzle opening. In particular, the locking pin can be designed with incremental diameters, so as to also ensure the closure of the nozzle opening to prevent contaminants from penetrating, while on the other hand, a hollow jet of spray liquid can be prepared with the closing means in the open position If a smaller incremental diameter extends into the nozzle opening as well.

It is further advantageous for the closing means to exhibit a head section, which is designed to create a solid jet spray or hollow jet spray, and in particular is replaceably arranged on the closing means. As an alternative, the entire closing means can be replaceably incorporated in the nozzle body. The locking pin is situated on the head section, so that replacing the head section makes it possible to change out the locking pin on the closing means at the same time. As a consequence, the spray nozzle unit can be configured with a nozzle opening-locking pin arrangement, depending on the operating conditions, so that a solid jet or hollow jet of spray liquid are alternately made available. This preferably takes place at low k-values for the nozzle, for example of about 1.2 (nozzle opening diameter: 3 mm). This ensures low water consumption at a comparatively large nozzle opening diameter.

It is further advantageous for the nozzle body to be configured for arrangement in a nozzle receptacle of a spraying system that serves in particular to spray a cutting head of a selective cut heading machine in underground mining. In order to arrange the nozzle body in a nozzle receptacle, the latter can exhibit a threaded section with which the nozzle body can be screwed into a nozzle receptacle. For purposes of screwing in, the nozzle body can further exhibit a wrench geometry, so as to screw the nozzle body into the nozzle receptacle via the threaded section using a tool.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional measures that improve the invention will be described in greater detail in conjunction with the specification using preferred exemplary embodiments of the invention based on the figures. Shown purely schematically on:

FIG. 1 is an exemplary embodiment of a spray nozzle unit with a closing means according to the invention in an open position;

FIG. 2 is an exemplary embodiment of the spray nozzle unit with a closing means according to the invention in a closed position;

FIG. 3 is another exemplary embodiment of a spray nozzle unit with a closing means according to the invention in a closed position;

FIG. 4 is another exemplary embodiment of the spray nozzle unit with a closing means according to the invention in an open position;

FIG. 5 is the other exemplary embodiment according to FIG. 3 and FIG. 4 in an exploded view.

PREFERRED EMBODIMENT OF THE INVENTION

FIG. 1 shows an exemplary embodiment of a spray nozzle unit 100 of the kind that can be used for spraying potentially explosive areas in underground mining. The spray nozzle unit 100 can be placed in a nozzle receptacle of a spraying system, which is used in particular to spray a cutting head of a selective cut heading machine in underground mining.

The spray nozzle unit 100 exhibits a nozzle body 10 that extends rotationally symmetrically around a central axis 13. In order to screw in the nozzle body 10, for example into a nozzle receptacle of a spraying system, the nozzle body 10 is provided with a threaded section 19. In order to screw the nozzle body 10 into the nozzle receptacle with a tool, the outside of the nozzle body 10 exhibits a wrench geometry 20, for example so as to screw in the nozzle body 10 with an open-end wrench, a box wrench, a spanner wrench or the like. The nozzle body exhibits roughly a cylindrical shape, and extends along the central axis 13, from a receiving side 10a to a spray side 10b. If the nozzle body 10 is placed in a nozzle receptacle of a spraying system, a water pressure prevails on the receiving side 10a, and the water present on the receiving side 10a can make its way through the nozzle body 10 and be sprayed on the spray side 10b. To this end, the spray side 10b of the nozzle body 10 exhibits a nozzle opening 11, through which the water exits toward the area to be sprayed.

According to the present invention, a closing means 12 is arranged in the nozzle body 10. The closing means 12 is designed as a clamping piston 12, and accommodated along the central axis 13 so that it can move back and forth between a closed position and the depicted open position. The clamping piston 12 is longitudinally guided in the nozzle body 10, and sealed against the inner wall of the nozzle body 10 with a sealing element 22. The receiving side 10a of the nozzle body 10 exhibits an insert element 21, in which the clamping piston 12 is also guided along the central axis 13 and sealed with another sealing element 23.

A feed channel 16 exhibiting a first feed channel section 16a and at least two second feed channel sections 16b extends through the clamping piston 12. The pressurized water coming from the receiving side 10a is routed through the feed channel 16a and into the feed port 16. The water supply is denoted with an arrow 24. The water passes through a filter 25, for example situated on the rear of the insert element 21 of the nozzle body 10.

The water passes through the first feed channel section 16a and the second feed channel sections 16b, and enters a pressure chamber 14 inside the nozzle body 10. The pressure chamber 14 is moveably bordered by the clamping piston 12. The water pressure present in the pressure chamber 14, for example at 4 bar, or preferably at 6 bar, moves the clamping piston 12 into the depicted open position. At the same time, a locking pin 12a present on the front of the clamping piston 12 releases the nozzle opening 11.

The movement of the clamping piston 12 toward the depicted open position takes place against the preloaded force exerted by a spring element 15. The latter is located on the side of the clamping piston 12 lying opposite the arrangement of the pressure chamber 14. As a consequence, the spring element 15 preloads the clamping piston 12 in the closing direction, in which the locking pin 12a extends through the nozzle opening 11. This prevents contaminants from being able to get into the nozzle opening 11 in the resting state. For example, the spring element 15 is designed as a helical compression spring, and is clamped between the insert element 21 and a collar of the clamping piston 12. As long as water supply 24 is ongoing, and as long as the pressure chamber 14 is thus pressurized, the clamping piston 12 remains in the depicted open position, and the water can exit the nozzle opening 12 as illustrated.

The pressure chamber 14 empties like a funnel into the nozzle opening 11 when the clamping piston 12 is in the open position, wherein the surfaces bordering the pressure chamber 14 exhibit a helical structure, which causes the water to exit the nozzle opening 11 with an angular momentum. This yields a large spraying angle, for example a spraying angle of 90°. Since the pressure chamber 14 extends rotationally symmetrically around the clamping piston 12 and the locking pin 12a, the twisting effect of the water exiting the nozzle opening 11 is further intensified. In the position shown behind the nozzle opening 11, the locking pin 12a can preferably be arranged inside the nozzle body 10 with the clamping piston 12 in the open position. In particular, it is possible to geometrically design the clamping piston 12 with the locking pin 12a and nozzle body 10 with the nozzle opening 11 in such a way as to have a small distance between the locking pin 12a and nozzle opening 11, so as to elevate the twisting effect of the exiting water. In particular, the water can as a result exit the nozzle opening 11 in a hollow jet, e.g., to achieve a k-value for the nozzle unit 100 of 1.2 (fluid pressure 6 bar, nozzle opening diameter 3 mm), for example.

A low-pressure chamber 17 is formed in the nozzle body 10 on the side of the clamping piston 12 facing away from the pressure chamber 14. A vent port 18 fluidically connects the low-pressure chamber 17 with the outside of the nozzle body 10. If the clamping piston 12 moves between the closed position and open position, the volume of the low-pressure chamber 17 changes, and the vent port 18 allows it to breathe. According to the depiction, the spring element 15 is arranged inside the low-pressure chamber 17.

FIG. 2 presents another view of the exemplary embodiment of the spray nozzle unit 100 according to FIG. 1. According to the depiction, the clamping piston 12 is situated in the closed position. In this arrangement, the locking pin 12a extends through the nozzle opening 11. The clamping piston 12 assumes the shown position inside the nozzle body 10 if no water is supplied via the receiving side 10a of the spray nozzle unit 100. Arranging the clamping piston 12a in the closed position diminishes the volume of the pressure chamber 14, and raises the volume out of the low-pressure chamber 17. As a consequence, compensating air streams through the vent port 18 into the low-pressure chamber 17. Also discernible is a geometric configuration of the clamping piston 12 allowing the rear clamping piston section 12 to be guided in the insert element 21. The sealing element 23 also ensures that the low-pressure chamber 17 is sealed against water pressure on the receiving side 10a of the spray nozzle unit 100. If the receiving side 10a is again pressurized, the water in turn passes through the supply channel 16 and into the pressure chamber 14, and the clamping piston 12 is moved to the open position against the force exerted by the spring element 15.

Another exemplary embodiment is depicted on FIGS. 3, 4 and 5. The same reference numbers here denote the same parts as in the first exemplary embodiment. The difference relative to the initially described spray nozzle unit is that the nozzle body 10 here consists of a nozzle connecting part 10c and a main nozzle part 10d. The latter are joined together by a bore ring (spring ring) 26. The nozzle opening 11 through which the clamping piston 12 extends is formed in the main nozzle part 10d. The latter also passes through a helical body 27, which comprises the closing means 12, and exhibits a circumferential groove 29 on its conical sealing surface 28 for accommodating the nozzle seal (O-ring) 30. The clamping piston 12 is arranged on a nozzle piston 31, which exhibits a guide section 34 whose exterior exhibits a circumferential groove 35 for accommodating the piston seal (O-ring) 36. The guide section 34 is made to abut the nozzle connecting part 10c via the compression spring 15. The locking pin 31c is situated on the guide section 34 as the closing means via a retaining bolt 31b. After screwed in, the nozzle connecting part 10c is sealed against the main nozzle part 10d by the additional piston ring (O-ring) 36. The relief hole is no longer required in this embodiment. The clearances between the individual bodies allows air to escape into the intermediate chamber 37. After installation, the nozzle body 10 can no longer be opened, at least not non-destructively. Dividing the nozzle body 10 into the nozzle connecting part 10c and main nozzle part 10d provides a range of various possible connections to choose from without having to alter the nozzle components. The exemplary embodiment selected presents a screwed connection of the nozzle connecting part 10c and main nozzle part 10d. Any type of threads can here be used. The division into two parts also makes it possible to turn or tighten the main nozzle part 10d independently of the nozzle connecting part 10c. This configuration is especially important when the nozzle has to be hooked up to piping or silo walls, and must remain outwardly tightly sealed (e.g., due to the risk of explosion). In prior art, a screw joint had to be incorporated between the nozzle and piping, so that both ends could be screwed together tightly.

The insert part of the nozzle body 10 is protected against contaminants in area 10a by a sieve 38. The sieve 38 is fixed in place by a bore ring 39, so that too strong a flow cannot tear it away.

The closing means 12 exhibits a helical body 27, the cross section of which is shown in detail A. Changing the channels 40 in the helical body 27, e.g., the number, position relative to center of gravity, depth and width, makes it possible to achieve variations in terms of the droplet size, spray angle (jet cone) and flow rate (K value variations), without having to change the other components in any way.

As already described above, the closing means 12 is provided with a nozzle seal (O-ring) 30 in this embodiment. Given a drop in pressure when the water supply is stopped, this O-ring makes it possible to keep the nozzle body 10 sealed to the outside, i.e., the extinguishing water only reaches as far as the nozzle outlet opening 11 closed by the clamping piston, and the nozzle line (not shown) also remains filled with water. This characteristic is very important in extinguishing systems, where very rapid opening times are crucial. Because the extinguisher supply lines are always filled with water, virtually no delay is to be expected in triggering the extinguishing system. Introducing the seal 30 in a circumferential groove 29 in the conical sealing surface 28 produces no additional delays in opening the nozzle, since there is no vertical travel.

It is very especially advantageous that the nozzle body 10 be held tightly even to the outside by the locking piece 27 or pressure hull 27 while interacting with the seal 30 designed as an O-ring and exposed to the resilient force F exerted by the compression spring 15. The resilient force F of the compression spring 15 acting on the nozzle piston 31 presses the seal 30 of the helical body 27 against the interior wall of the main nozzle part 10d, thereby preserving the seal. Selecting various spring configurations or various spring rates also makes it possible to determine the residual pressure in the extinguisher water supply line and change it as desired.

The invention is not limited in its configuration to the preferred exemplary embodiments indicated above.

Rather, a number of variants are conceivable, which make use of the described solution even given embodiments that are different. All features and/or advantages arising from the claims, specification or drawings, including structural details, spatial arrangements and procedural steps, can be essential to the invention both taken separately and in the most varied of combinations.

REFERENCE LIST

• 100 Spray nozzle unit
• 10 Nozzle body
• 10a Area/receiving side
• 10b Spray side
• 10c Nozzle connecting part
• 10d Main nozzle part
• 11 Nozzle opening
• 12 Closing means, clamping piston
• 12a Locking pin
• 12b Head section
• 13 Central axis
• 14 Pressure chamber
• 15 Spring element
• 16 Feed channel
• 16a First feed channel section
• 16b Second feed channel section
• 17 Low-pressure chamber
• 18 Vent port
• 19 Threaded section
• 20 Wrench geometry
• 21 Insert element
• 22 Sealing element
• 23 Sealing element
• 24 Water supply
• 25 Filter
• 26 Bore ring (spring ring)
• 27 Helical body
• 28 Sealing surface
• 29 Circumferential groove
• 30 Nozzle seal (O-ring)
• 31 Nozzle piston
• 34 Guide section
• 35 Circumferential groove
• 36 Piston seal (0-ring)
• 37 Intermediate chamber
• 38 Sieve
• 39 Bore ring
• 40 Channels
• F Spring force

Claims

1. A spray nozzle unit for spraying potentially explosive areas in underground mining, comprising a nozzle body that has a nozzle opening for ejecting spray liquid, wherein in that the nozzle body incorporates a closing means that closes the nozzle opening with the spray nozzle unit in an unpressurized state.

2. The spray nozzle according to claim 1, wherein the closing means is designed as a clamping piston, which is reciprocatingly incorporated in the nozzle body along a central axis of the nozzle body.

3. The spray nozzle according to claim 2, wherein the closing means is able to reciprocate between a closed position and an open position along the central axis by pressurizing the spray nozzle unit with spray liquid.

4. The spray nozzle according to claim 3, wherein the closing means has a locking pin for at least partial immersion into the nozzle opening in its closed position.

5. The spray nozzle according to one of the aforementioned claims, wherein the nozzle body includes a pressure chamber movably bordered by the closing means.

6. The spray nozzle according to claim 5, wherein the pressure chamber can be pressurized with spray liquid, wherein the pressure chamber is preferably arranged in such a way that the closing means can be moved from the closed position to the open position by pressurizing the pressure chamber.

7. The spray nozzle according to claim 3, wherein a spring element is provided that preloads the closing means in the closed position.

8. The spray nozzle according to claim 6, wherein the closing means exhibits a feed channel through which the pressure chamber can be pressurized with spray liquid.

9. The spray nozzle according to claim 6, wherein the pressure chamber is fluidically connected with the nozzle opening when the closing means is released from the closed position.

10. The spray nozzle according to claim 5, wherein the nozzle further includes a low-pressure chamber that is movably bordered by the closing means on a side lying opposite the pressure chamber.

11. The spray nozzle according to claim 10, wherein a vent port that links the low-pressure chamber with the outside of the nozzle body is situated in the nozzle body.

12. The spray nozzle according to claim 5, wherein the pressure chamber empties like a funnel into the nozzle opening with the closing means in the open position, wherein the surfaces bordering the pressure chamber at least partially exhibit a helical structure that allows the spray liquid to exit the nozzle opening with an angular momentum.

13. The spray nozzle according to claim 12, wherein the nozzle opening has a diameter of 1 mm to 6 mm.

14. The spray nozzle according to any one of claims 1-4, wherein the closing means has a head section, which is designed to create a solid jet spray or hollow jet spray, and is replaceably arranged on the closing means.

15. The spray nozzle according to any one of claims 1-4 or 7, wherein the nozzle body is configured for arrangement in a nozzle receptacle of a spraying system that serves to spray a cutting head of a selective cut heading machine in underground mining.

16. The spray nozzle according to any one of claims 1-4 or 7, wherein the nozzle body comprises a nozzle connecting part and a main nozzle body, which are detachable or undetachable in design.

17. The spray nozzle according to any one of claims 1-4 or 7, wherein the nozzle body has a helical body, which comprises the closing means and has channels to adjust the droplet size, spray angle and flow rate of the spray nozzle unit.

18. The spray nozzle according to claim 17, wherein the helical body has a conical sealing surface, which circumferentially incorporates a groove that accommodates an O-ring seal.