Working machine and method for reducing the formation of dust during track construction works

Abstract

The invention relates to a working machine (20) for track construction works, wherein: the working machine (20) has at least one working region (21) in which ballast (32) is moved; and high-pressure water nozzles (28) are situated on the working machine (20) near to the working region (21) and are designed to generate a water spray of a defined width and length around the working region (21). The invention also relates to a method for reducing the formation of dust during track construction works using a working machine (20) for track construction works.

Description

[0001] The invention relates to a work machine for track construction work, wherein the work machine has at least one working area in which ballast is moved, and to a method for reducing dust development during track construction work with a work machine.

[0002] Examples of such work machines include tamping machines, ballast cleaning machines, track renewal trains (track renewal using assembly line technology), and excavators. A track tamping machine, also called a ballast tamping machine or tamping train, is a track construction machine for compacting the ballast (tamping) in the superstructure beneath the sleepers. A tamping machine has a tamping unit equipped with vibrating tamping tines that plunge into the ballast and then press and compact the ballast beneath the sleepers through horizontal movements. A ballast cleaning machine removes the ballast from the track bed, cleans it, and then re-deploys it. A renewal train also removes and replaces the sleepers.

[0003] During track renewal, dust in the form of insoluble mineral dust is released during the handling of ballast. This ballast can be basalt or a rock type other than ballast (e.g., limestone).

[0004] In tamping machines, dust is generated, particularly in the working area of ​​the tamping picks used to compact the ballast. In ballast cleaning machines and track renewal trains, a particularly dusty working area is the scraper chain, which is used to remove the old ballast from the track bed. Other work areas with high levels of dust generation are transfer points between ballast conveyor belts or ballast drop points, or areas where sleepers are removed from or reinserted into the ballast.

[0005] Particles with a diameter larger than 10 µm – so-called coarse dust – mostly cling to the nasal hairs or the mucous membranes of the nasopharynx. However, smaller and tiny dust particles can penetrate deep into the lungs (alveoli) via the trachea and bronchi. Therefore, fine dust is also referred to as inhalable dust (E-dust - particles smaller than 10 µm) or respirable dust (A-dust - particles smaller than 2.5 µm). In addition to the influence of these dust sizes, all types of gravel also contain quartz.Thus, quartz and certain asbestos fibers (especially blue asbestos) are classified as scarring (fibrogenic) dusts according to their main effect, since after frequent exposure over a long period (due to chronic inhalation) they lead to a progressive remodeling of the lung tissue (pulmonary fibrosis), which is accompanied by functional impairment of respiration and gas exchange (ventilation and diffusion disorders).

[0006] There are various measures known to solve the problem, which are often combined: Combination of blowing ventilation and dust removal, sufficient weathering times Enclosures Use of dust binding agents Humidification, wetting or spraying of the roadway

[0007] The use of water sometimes brings with it new problems, which limit its use. For example, if the ballast pile is completely saturated beforehand, the tunnel drainage system can be severely affected or pollutants can be washed out of the track bed. The contaminated water must be collected and disposed of or treated accordingly.

[0008] Especially in railway construction, dust extraction combined with pre-injected water has been defined by the BG BAU / Federal Railway Authority as the most effective method to date for dust reduction. The Federal Railway Authority has mandated the installation of extraction and enclosure systems in the area of ​​dust sources generated by ballast cleaning machines. In addition to the extremely high power required by the extraction systems (400 kW) and the associated heat generation from the machine and enclosures, this has further disadvantages, including the associated logistics (extraction pipe routing, filter system, automatic cleaning of filter inserts), the actual space requirements, and the storage (and subsequent disposal) of contaminated dust during cleaning and filtering operations.The arrangement of the extraction and filter systems also limits the accessible work area, and in the case of a filter and machine unit traveling on the parallel track (if any!), the opposite track is restricted for other logistics or railway construction work. The achievable work output is reduced, the required working time for personnel in the work area increases, and the available working and safety area is reduced.

[0009] A work machine of this type is known from EP 1 860 240 A1. It sprays liquid onto the ballast. The liquid can be applied as a mist or as a jet.

[0010] Another work machine of this type is known from WO 91 / 15 630 A1, where the ballast is sprayed with water.

[0011] From DE 101 39 765 A1 a working machine for cleaning ballast is known, where the ballast is sprayed, working with operating pressures of 40 - 80 bar.

[0012] Further work machines are known from GB 2 152 984 A and CN 11 26 26 941 A.

[0013] The invention is based on the technical problem of creating a work machine for track construction work, which has at least one working area where ballast is moved, and in which the reduction of dust generation is improved. A further problem is the provision of a corresponding method.

[0014] The solution to the technical problem is provided by a working machine having the features of claim 1 and a method having the features of claim 10.

[0015] Further advantageous embodiments of the invention emerge from the subclaims.

[0016] The work machine for track construction work has at least one work area where ballast is moved. High-pressure water nozzles are arranged on the work machine near the work area and are designed to generate a water mist of a defined width and length around the work area. High pressure is understood to mean a pressure of ≥ 40 bar. The pressure is preferably between 40 and 80 bar. More preferably, the water mist is generated continuously and at a constant speed. However, designs are also possible in which the water mist is generated in pulses, for example every three to five seconds. In this case, even higher pressures can be used. The droplet size of the water mist is less than 1 mm and is preferably between 50 and 150 µm. The length and width of the water mist preferably depends on the type of work machine and the type of work area.The width of the water mist is preferably greater than 3 m and can be up to 20 m or more. However, in individual cases the width can also be less than 3 m. In particular, a certain width immediately in front of and in the work area is misted so that when the work machine moves longitudinally, the work area is always entered in a standing water mist. It can also be provided that the width of the water mist is adapted to the length of the sleepers, whereby, for example, the width of the water mist is at least 5 to 10 cm greater than the length of the sleepers. The length of the water mist is preferably greater than 2 m, more preferably greater than 4 m. However, there are also applications in which the water mist is less than 2 m long. The water nozzles can be aligned in such a way that they generate the water mist in the longitudinal direction or direction of movement of the work machine.If the water nozzles are positioned in front of the work area, they spray backward (opposite the direction of travel). If they are positioned behind the work area, they spray in the direction of travel. The water nozzles can also be positioned additionally or only laterally, and then spray perpendicular to the direction of travel. The work area is preferably a scraper chain and / or a ballast transfer point between two conveyor belts and / or the insertion point of the tamping pick of a tamping machine or a bucket or similar device on an excavator and / or discharge points for ballast into a track bed.

[0017] The number of water nozzles per dust-generating location is preferably between 4 and 50, which are preferably supplied with water by a common pump. As the number of water nozzles increases, the pump must provide a correspondingly greater pumping capacity, or multiple pumps must be used. A number of water nozzles between 30 and 40 has proven particularly efficient. The pumping capacity is, for example, between 200 and 300 l / h.

[0018] Another advantage of fogging is that it allows fine dust particles to agglomerate into larger grains. These then sink to the ground and can be transported away with the moistened gravel being collected, or they can be vacuumed more easily. This agglomeration effect can be further enhanced by adding dust binding agents. In this case, a further advantage of fogging is that the amount of binding agent used can be significantly reduced compared to conventional application methods. Compared to previously described known methods for dust prevention, this results in a significant reduction in material usage.

[0019] In one embodiment, the work machine is designed to adjust the orientation of the water nozzles and / or the high pressure at the water nozzles. The adjustability can be manual or automatic. This adjustability allows the work machine to react to changing external influences such as wind. The fog wall is influenced depending on the wind strength and direction. These influences can be at least partially compensated for by the settings, so that almost comparable working conditions always exist. With automatic adjustment, for example, the wind strength and direction can be measured by sensors, with the parameters for the orientation of the water nozzles and / or the set high pressure being read from a characteristic curve or table.Additionally or alternatively, a camera or laser can be provided that records the water mist and changes the settings based on the captured image data until the desired shape of the water mist is achieved.

[0020] In one embodiment, the work machine has at least one fan and air guiding structures for generating a laminar flow, with the water nozzles being designed to spray the water mist into the laminar flow. This makes it possible, in particular, to ensure that the water mist can be set to a sufficiently long duration. The air guiding structures are, for example, air baffles, which may also have additional coatings.

[0021] In a further embodiment, the work machine has at least one suction device arranged opposite the water nozzles. This allows the water and dust particles to be collected. For example, the suction device is designed as a suction fan with a cyclone separator. The water can then be cleaned and fed back to the water nozzles. It can also be provided that the orientation of the suction device is adjustable.

[0022] In a further embodiment, the work machine has at least one conveyor belt for gravel, wherein at least along a portion of the conveyor belt, the conveyor belt is enclosed by a circulating belt. The work machine further has a water bath configured such that a portion of the circulating belt is located in the water bath. This allows the moistened belt to absorb rising dust from the conveyor belt and divert it to the water bath. The circulating belt is configured, for example, as a fleece. Alternatively, the belt can also be electrostatically charged, in which case the water bath is omitted.

[0023] In an alternative or additional embodiment, the work machine has at least one conveyor belt for gravel, wherein two circulating belts are stretched over the conveyor belt at least along a partial section of the conveyor belt, wherein the work machine has at least one water bath which is designed such that a part of the circulating belt is located in the water bath. Here, too, the belts are preferably designed as nonwovens. Furthermore, each belt is preferably assigned its own water bath. Further preferably, a pressure roller is provided which presses the dust-contaminated dirty water out of the belt before it is immersed in the water bath again. The dirty water can then be cleaned and fed to the water bath or other units of the work machine. Alternatively, the belts can be electrostatically charged, in which case the water baths are no longer required.

[0024] In a further alternative or supplementary embodiment, the work machine comprises at least one conveyor belt for ballast, wherein a hood is arranged above the conveyor belt at least along a portion of the conveyor belt. Water nozzles are arranged on the hood and are designed to generate a radial water jet on the inner wall of the hood. The water jet is then injected onto one side of the hood in such a way that the hood is covered with a permanently continuous film of water over its entire length and width. The water jet collects dust particles and flows off the opposite side.

[0025] The draining wastewater can then be cleaned. The airflow in the enclosed space between the conveyor belt and the hood can be turbulent to dislodge additional dust particles from the transported gravel and bring dust particles already in the air into contact with the surrounding water jet. Alternatively, the hood can be electrostatically charged, in which case the water jet is eliminated.

[0026] In a further alternative or additional embodiment, the work machine has at least one conveyor belt for gravel, wherein fans for generating a laminar air flow are arranged next to the conveyor belt at least along a portion of the conveyor belt, wherein the air flow is oriented transversely to the conveying direction of the conveyor belt, wherein the work machine further has water nozzles arranged on the opposite side of the conveyor belt. The water nozzles generate a vertically descending water mist next to the conveyor belt, which binds the dust. The droplet size is preferably between 50 µm and 500 µm and more preferably between 50 and 100 µm. The dirty water falling downwards can be collected in a channel running parallel to the conveyor belt, for example, and then cleaned and reused.

[0027] In a further embodiment, the work machine additionally has at least one device which is designed to generate a water mist in front of the work machine in pulses. As a result, the work machine always moves into a descending water mist, so that dust formation around the work machine is effectively reduced. The device generates a water mist with a droplet size of less than 500 µm, with a droplet size of 100 µm being preferably generated. The pressure is preferably between 20 and 30 bar and more preferably 25 bar. Preferably, an intermediate storage device is provided which maintains the pressure. The pressure in the intermediate storage device is preferably between 27 and 40 bar, more preferably between 35 and 40 bar and more preferably between 38 and 40 bar. The length of the water mist is preferably between 35 and 50 m. The width is preferably between 3 and 5 m. The water mist is preferably approx.1 m above the track bed in front of the work machine. This allows the water to be deposited in a targeted manner and at the same time does not obstruct visibility, thus increasing work safety. A water mist tunnel or blanket is clearly formed, into which the mobile work machine moves. As the work areas or work units (e.g. a scraper chain) are usually not directly at the head of the work machine, but a few meters behind it, it is advantageous if the work machine moves into the water mist tunnel. The dust that then rises absorbs the moisture in the form of water droplets and sinks back to the ground. The water consumption is considerably lower than with conventional sprinkling systems. For example, 125 liters of pulsed misted water can achieve a similar effect to 10,000 liters of water when sprinkling to wet the track bed. Over an eight-hour shift, around 17,000 liters of water are sufficient, which corresponds to approx.240,000 liters of air are added. Preferably, 3 to 6 pulses per minute are generated. The water mist can consist of pure water or contain additives. Devices for generating such water mist tunnels are known, for example, from firefighting, where they are used for the so-called impulse extinguishing process and are manufactured, for example, by the company IFEX. The entire device does not have to be integrated into the working machine. For example, only the actual impulse cannon is integrated into the working machine, whereas other parts, such as the water tank and pressure accumulator, are arranged on a rail-mounted platform in front of the working machine.

[0028] Alternatively or additionally, the procedure may provide for a person to wear the device for pulsed nebulisation.

[0029] In an alternative embodiment, the device for reducing dust development during track construction work comprises at least one water chamber, at least one pressure chamber, at least one quick-release valve, at least one nozzle and a controller, wherein the controller is designed to control the at least one quick-release valve in a pulsed manner so that the pressure chamber and water chamber are pressure-connected and a water mist is generated, wherein the device has means for detachably connecting the device to a rail-bound platform, or the device has a rail-bound platform.

[0030] The platform can be arranged in front of the work machine and pushed by the work machine.

[0031] In one embodiment, the means for generating the water mist are arranged on a platform separate from the drive machine, with the water mist being generated opposite to the direction of movement of the working machine. The platform can have its own drive or be towed. The advantage of this is that no additional mechanical stress is placed on the area in front of the working machine and thus near the process-related track hole in the area of ​​the clearing chains of a working machine.

[0032] The individual measures can also be combined. For example, the first means can be located on a platform separate from the working machine, with additional means integrated into the working machine and / or located directly in front of it.

[0033] It can further be provided that the means in front of or in the working machine generate the water mist in different directions (forward, backward, left, right). It can further be provided that the means in or immediately in front of the working machine generate the water mist at lower pressure and with a shorter length.

[0034] In a further embodiment, the water mist is detected by at least one sensor, and the frequency of the pulses is adjusted depending on the sensor data. This ensures that a sufficient wall of water mist is always present. The sensor is designed, for example, as a camera. Additionally, object detection can be performed using the sensor. It can be provided that the generation of water mist is interrupted when an object (e.g., a person) is detected.

[0035] In a further embodiment, a sensor system is provided for detecting the distance to the working machine. The data from this sensor system can be used to control a drive motor of the platform or the device itself. For example, the device can be pivoted vertically or the working pressure can be adjusted. The sensor system can be designed as a laser, radar, or lidar sensor. However, the sensor system can also be designed as a stereo camera. The data from the sensor system for detecting the distance to the working machine can also be used for object detection.

[0036] In a further embodiment, several means are arranged in parallel. This makes it easier to set the desired width of the water mist wall. A further advantage is that the various means can be controlled at different times, allowing an overall higher pulse rate to be generated. Individual means can also be controlled only on a case-by-case basis, for example if the sensor detecting the water mist detects too little water mist. Alternatively, the multiple means can be arranged radially distributed around an axis, in which case the means can rotate around the axis and generate a water mist one after the other.

[0037] In a further embodiment, the means are designed to be pivotable. The means can be designed to be horizontally and / or vertically pivotable. The vertical pivoting allows the angle of the water mist and thus also its length to be adjusted. For example, the means can be pivoted depending on the data from the sensor system for detecting the distance to the work machine.

[0038] Furthermore, the nozzles can be monitored, for example, for blockage or icing. It can also be provided that the nozzles are heated if there is a risk of icing.

[0039] In a further embodiment, the nozzle is adjustable and / or designed so that attachments can be attached in front of it to adjust the mist. The attachments can be grids, for example. Furthermore, perforated discs can be provided that can be rotated relative to each other. This allows the mist to be increased, for example, when used on a work machine, although this is at the expense of the length of the water mist.

[0040] The pressure chamber is preferably connected to a compressor, which continually builds up the necessary pressure of, for example, 25 bar. The aforementioned buffer can be arranged between the pressure chamber and the compressor. The water chamber is connected to a water tank or a water pipe, so that the water chamber is continually refilled. The water tank can also be connected to a water pipe. The water can be pumped under pressure from the water tank into the water chamber. The compressor for the pressure chamber can also be used for this purpose, which then has two functions.

[0041] In a further embodiment, the device has at least one sensor for detecting the water mist, wherein the control unit is designed to control the quick-release valve depending on the data from the sensor.

[0042] In a further embodiment, the device is designed to be pivotable. This makes it possible, in particular, to adjust the width of the water mist wall.

[0043] With regard to the procedural details, reference is made in full to the preceding statements.

[0044] The invention is explained in more detail below using preferred embodiments. The figures show: Fig. 1 is a schematic representation of a work machine for track construction work, Fig. 2 is a schematic detailed view in the area of ​​the work area, Fig. 3 is a schematic front view of a conveyor belt for ballast in a first embodiment, Fig. 4 is a schematic front view of a conveyor belt for ballast in a second embodiment, Fig. 5 is a schematic front view of a conveyor belt for ballast in a third embodiment, Fig. 6 is a schematic perspective representation of a conveyor belt for ballast in a further representation, Fig. 7 is a highly simplified schematic representation of a device for the pulsed generation of water mist, Fig. 8 is a schematic plan view of a device and a work machine and Fig. 9 is a schematic side view of the device and work machine.

[0045] In the Fig. 1 A schematic representation of a work machine 20 for track maintenance work is shown, moving in the direction of travel F. The work machine 20 is, for example, a track renewal train, a ballast cleaning machine, or a tamping machine. The work machine 20 has at least one working area 21 where ballast is moved. In the example shown, this is, for example, a scraper chain, by means of which ballast is removed from the track bed for cleaning.

[0046] In the Fig. 2 2 shows a device 22 for reducing dust development in a work area 21 of the work machine 20. In the work area 21, gravel is moved so that dust particles 23 rise upwards. The device 22 has at least one blower 24 that draws in ambient air 25 and forces the drawn-in air through air guiding structures 26, creating a laminar air flow 27. At the end of the air guiding structures 26 opposite the blower 24, water nozzles 28 are arranged, which form fine water droplets 29 with a diameter of 100 to 500 µm using high pressure of ≥ 40 bar. The water droplets 29 are carried along by the laminar air flow 27. When dust particles 23 then collide with water droplets 29, they combine. On the side of the working area opposite the water nozzles 28, a suction device 30 is arranged, which, for example, has a suction fan for driving a cyclone separator.The water droplets 29 with the bound dust particles 23 are then sucked in by the suction device 30. The dirty water collected in this way can then be cleaned and fed back to the water nozzles 28. Dust exposure can thus be effectively reduced by the device 22.

[0047] In the Fig. 3 3 shows a device 31 for reducing dust development when transporting gravel 32 on a conveyor belt 33. The device 31 has a circulating belt 34 which wraps around the conveyor belt 33 and runs over rollers 35. Not all of the rollers have to be designed as drive rollers. Some rollers 35 can also be designed as simple deflection rollers. The device 31 also has a water bath 36, with a part of the circulating belt 34 always being located in the water bath 36. If dust particles rise during movement, they adhere to the moist belt 34 and are transported to the water bath 36, where they are released. In addition, mechanical means can be provided to release the dust particles adhering to the belt 34 from the belt 34.

[0048] In the Fig. 4 An alternative device 31 for reducing dust formation when transporting gravel 32 on a conveyor belt 33 is shown. In contrast to the embodiment according to Fig. 3 The device 31 has two circulating belts 34 that almost completely cover the conveyor belt 33. Additionally, each belt 34 is assigned a pressure roller 37, by means of which, during the return transport of the belt 34, the water with the adhering dust particles 23 is pressed out of the belt 34 and directed into a dirty water tank 38, where it can then be cleaned.

[0049] In the Fig. 5 Another alternative device 31 for reducing dust generation when transporting gravel 32 on a conveyor belt 33 is shown. A hood 39 is arranged next to and above the conveyor belt 33. A water nozzle 40 is arranged at one edge of the hood 39, generating a water jet 41 of fresh water 43 that runs radially along the inner wall of the hood 39 and discharges as dirty water 42 at the opposite edge.

[0050] In the Fig. 6 3 shows a further alternative device 31 for reducing dust development when transporting gravel on a conveyor belt 33. Blowers 44 are arranged along a section of the conveyor belt 33 and generate a laminar air flow 45 transverse to the transport direction TR of the conveyor belt 33. On the opposite side of the conveyor belt 33, water nozzles 46 are arranged, which generate a downward-directed water mist 47 from above. Gravel particles 23 rising upwards during transport are blown into the water mist 47 by the laminar air flow 45, combine with water droplets and fall downwards into a drainage channel 48. This dirty water 49 is fed to a filter unit 50 and the purified water 51 is fed back to the water nozzles 46.

[0051] In the Fig. 7 , the device 1 for reducing dust development is shown, which can be used in addition to or alternatively to the high-pressure water nozzles 28. The device 1 has a pressure chamber 2 and a water chamber 3, which are connected to one another via a quick-release valve 4. The device 1 also has a compressor 5, which is connected to the pressure chamber 2. An intermediate storage device can be arranged between the pressure chamber 2 and the compressor 5, which has a higher pressure than the working pressure in the pressure chamber 2. The water chamber 3 is connected to a water tank 6. A nozzle 7 is arranged on the water chamber 3. The device 1 also has sensors 8 for detecting a water mist and a distance to the work machine, as well as a controller 9, which controls the quick-release valve 4.By opening the quick-release valve 4, the water in the water chamber 3 is forced through the nozzle 7 and creates a water mist. The exit speed can be up to 400 km / h and more. The length L of the water mist is preferably between 35 m and 50 m and the width between 3 m and 5 m. Due to the resulting recoil forces, the device 1 must be mounted accordingly. Furthermore, a pressure sensor (not shown) can be arranged in the pressure chamber 2 and is connected to the controller 9 for data purposes. The controller 9 thus only controls the quick-release valve 4 when the desired working pressure in the pressure chamber 2 is reached. The desired working pressure is adjustable and is preferably 25 bar. However, the working pressure can also be changed during operation depending on the data from the sensors 8.

[0052] In the Fig. 8 A plan view is shown, wherein the device 1 is arranged on a platform 10. The platform 10 moves approximately 50 m in front of a working machine 20, for example a ballast cleaning machine, which moves in the direction of travel F. The movement of platform 10 and working machine 20 can be synchronized. The device 1 generates a water mist 12 having a length L, a width B, and a height H, wherein the height H directly in front of the working machine 20 is approximately 1 m (see Fig. 9 ). The water mist 12 forms a water mist wall that the rising dust cannot overcome. The device 1 is mounted on the platform 10 to absorb the recoil forces. Furthermore, the device 1 can be designed to pivot horizontally and / or vertically on the platform 10. List of reference symbols

[0053] 1 Device 2 Pressure chamber 3 Water chamber 4 Quick-release valve 5 Compressor 6 Water tank 7 Nozzle 8 Sensors 9 Control system 10 Platform 12 Water mist 20 Work machine 21 Work area 22 Device 23 Dust particles 24 Blower 25 Ambient air 26 Air guide structure 27 Air flow 28 Water nozzle 29 Water droplets 30 Drowning device 31 Device 32 Gravel 33 Conveyor belt 34 Belt 35 Roller 36 Water bath 37 Pressure roller 38 Dirty water tank 39 Hood 40 Water nozzle 41 Water jet 42 Dirty water 43 Fresh water 44 Blower 45 Air flow 46 Water nozzle 47 Water mist 48 Drain channel 49 Dirty water 50 Filter unit 51 Purified water LLength BWidth HHeight FDirection of travel TRTransportation direction

Claims

1. Working machine (20) for track construction work, the working machine (20) having at least one working area (21) at which ballast (32) is moved characterized in that water nozzles (28) operated at high pressure of ≥40 bar are arranged on the working machine (20) in the vicinity of the working area (21), which are designed in such a way as to produce a standing water mist of defined width and length around the working area (21), the droplet size of the water mist being less than 1 mm.

2. Working machine according to claim 1, characterised in that the working machine is designed in such a way that the alignment of the water nozzles and / or the high pressure at the water nozzles can be adjusted.

3. Working machine according to claim 1 or 2, characterised in that the working machine (20) has at least one fan (24) and air guide structures (26) for generating a laminar flow (27), the water nozzles (28) being arranged in such a way that they spray the water mist into the laminar flow.

4. Working machine according to one of the preceding claims, characterised in that the working machine (20) has at least one suction device (30) which is arranged opposite the water nozzles (28) (30), which is arranged opposite the water nozzles (28).

5. Working machine according to one of the preceding claims, characterised in that the working machine (20) has at least one conveyor belt (33) for ballast (32), wherein at least along a section of the conveyor belt (33), the conveyor belt (33) being enveloped by a circulating belt (34), the working machine (20) furthermore having a water bath (36) which is arranged in such a way that in each case a part of the circulating belt (34) is located in the water bath (36).

6. Working machine according to one of the preceding claims, characterised in that characterised in that the working machine (20) has at least one conveyor belt (33) for ballast (32), wherein at least along a section of the conveyor belt (33), two circulating belts (34) being tensioned over the conveyor belt (33), the working machine (20) having at least one water bath (36) which is arranged in such a way that in each case a part of the circulating belt (34) is located in the water bath (36).

7. Working machine according to one of the preceding claims, characterised in that characterised in that the working machine (20) has at least one conveyor belt (33) for ballast (32), wherein at least along a partial section of the conveyor belt (33) blowers (44) for generating a laminar air flow (45) are arranged next to the conveyor belt (33), wherein the air flow (45) is oriented transversely to the conveying direction (TR) of the conveyor belt (33), wherein the working machine (20) further comprises water nozzles (46) which are arranged on the opposite side of the conveyor belt (33).

8. Working machine according to one of the preceding claims, characterised in that characterised in that the working machine (20) has at least one conveyor belt (33), wherein a bonnet (39) is arranged over the conveyor belt (33) at least along a section of the conveyor belt (33), wherein water nozzles (40) are arranged on the bonnet (39), which are designed to generate a radial water jet (41) on the inner wall of the bonnet (39).

9. Working machine according to one of the preceding claims, characterised in that characterised in that the working machine (20) has at least one device (1) which is designed to generate a pulsating water mist in front of the working machine (20).

10. Method for reducing the formation of dust during track construction work with a working machine (20) for track construction work, the working machine (20) having at least one working area (21) at which ballast (32) is moved, by means of water nozzles (28) arranged in the vicinity of the working area (21), a water mist of defined width and length is generated around the working area (21) at a high pressure of ≥40 bar, the droplet size of the water mist being smaller than 1 mm.

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