Method for reducing dust during milling operation of a self-propelled ground milling machine and self-propelled ground milling machine

Abstract

The invention relates to a method for dust reduction during the milling operation of a self-propelled soil milling machine, in particular a road milling machine, recycler, or stabilizer. The invention further relates to a self-propelled soil milling machine, in particular a road milling machine, recycler, or stabilizer, for milling an area of ​​a soil surface to a milling depth.

Description

[0001] The invention relates to methods for reducing dust during milling operations of a self-propelled soil milling machine, in particular a road milling machine, recycler, or stabilizer. The invention further relates to a self-propelled soil milling machine, in particular a road milling machine, recycler, or stabilizer, for milling a portion of a soil surface to a milling depth.

[0002] Soil milling machines of this type are used in road and path construction and are described, for example, in EP3225738B1. They comprise a machine frame supported by driving gear and a drive motor, which typically provides the drive energy required for driving and working. The driving gear can be, for example, tracked drives or wheels. The drive motor can be, for example, an internal combustion engine, such as a diesel engine. A hybrid and / or electric motor drive is also possible. Such machines are preferably self-propelled and move under their own power over the subsoil to be worked. The central working device of soil milling machines of this type is a milling drum for removing soil material, which is rotatably mounted in a milling drum box mounted on the machine frame.The milling drum can have a hollow cylindrical base body, on the outer surface of which a plurality of milling tools, for example milling chisels, are mounted radially protruding from the outer surface. During operation, the milling drum rotates about a rotational axis that usually runs horizontally and transversely to the working direction of the soil milling machine. The milling tools are driven into the subsoil to be removed by lowering them into the subsoil to be removed and by moving the soil milling machine forward in a travel or working direction, whereby the subsoil is milled to a milling depth along the travel direction of the soil milling machine. The milling drum housing surrounds the milling drum like a hood and is open towards the ground so that the milling drum can protrude downwards beyond the lower edge of the milling drum housing for soil engagement.The milling drum box can comprise height-adjustable wall elements relative to the milling drum, such as a scraper shield, one or more side shields, and / or a front shield, which enable the lower sealing edge of the milling drum box to be adapted to different milling conditions, particularly with regard to milling depth and / or soil conditions. The removed milled material collected in the milling drum box is typically transported from there to a milled material conveyor through an ejection opening in the milling drum box and guided by the milled material conveyor to a discharge point. This is also referred to below as the milled material conveyor path. The milled material conveyor can comprise one or more conveyor belts arranged in series, such as an inner conveyor belt designed as a receiving conveyor belt and an attached or outer conveyor belt designed as a discharge conveyor belt.At the discharge point of the milled material conveyor system, the soil material is discharged onto the loading area of ​​a transport vehicle, for example a truck, for further removal of the milled material.

[0003] The milling and / or conveying or transporting of soil material can lead to significant dust development during milling operations of the soil milling machine. The resulting dust can impair the visibility and / or health of persons on or near the soil milling machine. Air in which these dusts are dispersed is referred to below as dusty air. To minimize the discharge of dust into the external environment of the soil milling machine, it is already known to equip soil milling machines of this type with an extraction system or dust extraction system.Depending on the design, the task of this extraction system is to control and reduce dust emissions, particularly in the area of ​​the milling drum box and / or in the area of ​​the milled material conveyor line, and either to direct them to specific points on the soil milling machine, for example to a milled material transfer point on the milled material conveyor system towards a transport vehicle, and / or to capture the resulting dust in order to reduce the overall dust emissions of the soil milling machine. Of particular relevance here are E-dust and A-dust, as defined in DIN EN 481. For this purpose, the extraction system typically comprises at least one extraction fan as part of an extraction air duct. The extraction air duct refers to the entirety of the devices through which the dust-laden air extracted from the milling drum box and / or part of a milled material conveyor channel of the milled material is transported from this extraction point orthis extraction point to a blow-off point through which the sucked-in air exits the soil milling machine, is guided or directed. Dust lying on the ground subsurface can also be sucked in and carried along with the extracted dust-laden air. The extraction fan, which has a suction or negative pressure side and a blow-out or positive pressure side, thus creates a negative pressure on the suction side and ultimately an air suction from the extraction point to the extraction fan. The extraction air duct is at least partially designed as a line / duct that is separate from the milled material conveying device, but can at least partially also form a common space with the milled material conveying device, particularly in the area of ​​the extraction point. The milled material conveying route and the extraction air duct orThe dust-laden air conveyed in the extraction air duct does not necessarily have to be spatially separated throughout, but can also be guided, at least partially, through the same spatial compartment. In particular, because the milled material conveying system in this type of floor milling machine is often enclosed by a housing perpendicular to the conveying direction of the milled material and thus runs in a channel-like overall structure, it is possible for at least parts or sections of the milled material conveying system to also be part of the extraction duct.A key aspect of the design of the extraction air duct is that the suction generated by the extraction fan can ultimately reach, ideally, the milling drum housing, in particular its interior, and / or part of the milled material conveying path of the milled material conveying system. As a result, dust-laden air can be extracted from the interior of the milling drum housing and / or the conveying path of the milled material conveying system and conveyed via the extraction air duct to the extraction fan and downstream to the blow-off point. Upstream and / or downstream of the extraction fan, it is already known to direct the extracted dust-laden air through a dust reduction device or dust separation device, for example, a filter and / or separation device, such as an electrostatic and / or fabric and / or cyclone filter, and / or a water sprinkler device at the end of a milled material conveyor belt.Generic floor milling machines with suction devices are known, for example, from the applicant's publications DE102012022879B4 and EP3225738B1.

[0004] Even though a number of measures are already known to reduce dust exposure, particularly for the operator, of a generic floor milling machine due to dust generated during the milling process, these measures are sometimes not yet optimal for the specific application at hand.

[0005] Based on this, it is therefore the object of the invention to provide a possibility of improving the operation of a suction device for extracting dust-containing air from the milling drum box and / or an area of ​​a milling material conveying channel of a ground milling machine adjoining the milling drum box.

[0006] The object is achieved with a method for reducing dust during milling operation of a self-propelled soil milling machine, in particular a road milling machine, recycler, or stabilizer, as well as with a self-propelled soil milling machine, in particular a road milling machine, recycler, or stabilizer, for milling a portion of a soil surface to a milling depth according to the independent claims. Preferred developments are specified in the dependent claims. The method according to the invention and the soil milling machine according to the invention can comprise the features of the prior art mentioned above.

[0007] A first aspect of the invention thus relates to a method for reducing dust during milling operations of a self-propelled ground milling machine. Among the known self-propelled ground milling machines, the method according to the invention is particularly suitable for road milling machines, cold milling machines, recyclers, or stabilizers. For details on the possible generic design of such ground milling machines for implementing this method, reference is made to the following explanations regarding the design of a ground milling machine according to a second aspect of the invention.

[0008] For the method according to the invention, it is initially provided that, in step a), a milling process is carried out and, in the process, a soil surface is traversed in a manner known per se in the prior art. The milling drum, which rotates and engages in the subsoil during the milling process, thus mills away soil material, moves it within the milling drum housing, and can shovel the resulting milled material, for example, onto a milled material conveyor. This can convey the collected milled material along a milled material conveyor line to a discharge point, for example for depositing and / or loading purposes. During these processes, dust can be generated, particularly in the area inside the milling drum housing and in the area of ​​the milled material conveyor.

[0009] In step b), in order to reduce dust emissions from the ground milling machine into its external environment, dust-laden air is extracted from a milling drum housing and / or an area of ​​a milling material conveying channel adjoining the milling drum housing during the ongoing milling process. Milling material removed from the ground surface is conveyed through the milling material conveying channel from the milling drum housing to a discharge point on the ground milling machine. Specifically, the milling material conveying channel can, for example, comprise one or more at least partially enclosed conveyor belts.The dust-laden air is extracted by means of an extraction device comprising an extraction air duct extending from the extraction point where the dust-laden air is extracted from the milling drum housing and / or the area of ​​the milled material conveying duct adjoining the milling drum housing to the blow-off point through which the extracted air can exit the ground milling machine. The extraction point can extend over several areas and / or locations. The extraction air duct allows the extracted dust-laden air to be moved along a spatially defined path within the ground milling machine.In particular, the suction can also achieve a spatial separation of the dust-containing air from the milled material, so that the dust-containing air can be treated separately from the milled material for dust reduction purposes in the manner described in more detail below, and the dust contained in the dust-containing air can be separated, concentrated and collected at a defined location within the floor milling machine.

[0010] In step c), the extracted dust-laden air is fed to a separation device, wherein the separation device has a separation chamber formed separately from the milled material conveying channel. The separation device thus comprises at least one separation chamber, which defines a separation volume or a spatial compartment in which dust particles contained in the extracted dust-laden air are separated from the extracted dust-laden air, thereby reducing the dust load in the respective air volume or the dust concentration.

[0011] In the separation chamber, in step d), the dust-laden air is passed through a separation section, where it comes into contact with a separation liquid. In the separation section, the dust-laden air is thus thoroughly mixed with the separation liquid. The separation liquid can, in particular, be water. It is possible to add additives, such as one or more surfactants and / or defoamers, to the water used as the separation liquid. Contact between the dust-laden air and the separation liquid can lead to the formation of larger and heavier dust particle agglomerates from individual dust particles. More importantly, however, is that the dust particles are absorbed into the separation liquid in this step or later and collected there in step e).This ultimately results in the separation of dust from the supplied dust-laden air and its absorption into the separation fluid. The separation of dust contained in the dust-laden air thus primarily occurs because dust particles are sooner or later absorbed by the separation fluid and, for example, dispersed in it.

[0012] The subsequent step e) involves collecting the dust absorbed in the separation fluid within a separation fluid reservoir. The separation fluid reservoir thus represents a volume of the separation fluid in which the dust particles absorbed by the separation fluid are collected, collected, and concentrated during the ongoing milling and extraction operations. The dust particles removed from the dust-laden air thus remain in the separation fluid, at least for the time being.

[0013] The extracted air, purified after passing through the separation fluid, is discharged in step f) downstream of the separation section from the separation chamber via an exhaust air outlet, which can represent the final step in the air's passage through the separation chamber. The "extracted air" refers to the volume of air conveyed by the extraction device from the extraction point to the blow-off point. It is understood that this volume of extracted air is drawn upstream of the extraction device and forced downstream of the extraction device. The extraction device itself can be positioned at various points within the extraction air duct, for example, downstream of the separation chamber in the air duct direction, so that the extracted air is drawn through the separation chamber, or upstream of the separation chamber in the air duct direction, so that the extracted air is forced through the separation chamber.Several extraction devices can also be arranged within the extraction air duct, in particular at different locations, for example in parallel and / or series arrangement.

[0014] Finally, it is provided for the method according to the invention that in step g) the purified air is passed on to a blow-off location via which the extracted and then purified air or air with at least a reduced dust content exits the ground milling machine.

[0015] Depending on the specific design of the ground milling machine, steps f) and g) can be carried out separately in time and / or space and / or simultaneously in time and / or space.

[0016] The method according to the invention therefore provides overall that the extracted dust contained in the extracted dust-containing air is separated from the air by means of a passage of this air through the separation liquid and at least temporarily passes into the separation liquid and is collected there on the floor milling machine during ongoing milling operation.

[0017] The method according to the invention is particularly suitable for particle sizes commonly referred to as "dust particles", e.g. E-dust and A-dust, as defined in DIN EN 481.

[0018] It can be detrimental if larger particles enter the separation chamber. This can not only damage components of the separation system, but also adversely affect the separation efficiency of the separation system. It is therefore advantageous if the extracted dust-laden air is directed upstream of the separation system through a pre-separator. The pre-separator is designed to separate particles that are larger than the relevant dust particles, such as coarse-grained millings, small stones, etc. The pre-separator can be, for example, a centrifugal separator, such as a cyclone separator, an inertial separator, a fabric-like structure, such as a wire mesh, or similar.

[0019] It is advantageous if the amount of separation liquid contained in the separation device is reduced as little as possible over the course of ongoing operation. Furthermore, it may be desirable if the cleaned air blown out of the soil milling machine contains as little or as little entrained separation liquid as possible. It is therefore advantageous if, downstream of the separation section, i.e. in particular between the separation chamber and the blow-off point, the cleaned, extracted air in the extraction air duct is guided through a device for separating droplets of separation liquid from the cleaned, extracted air. This can be, for example, a droplet separator, e.g. a centrifugal separator, such as a cyclone separator, a lamella separator, a wire mesh separator or similar.It may be provided that a return line is present which connects the device for separating droplets of separation liquid to the separation liquid reservoir, so that portions of separation liquid separated from the air by this device can be returned to the separation liquid reservoir.

[0020] Regarding the specific design of the mixing of the separation fluid with the extracted dust-laden air, various procedures are possible, which can also be combined with one another. For example, it can be provided that the separation fluid is atomized into droplets / mist within the separation device and the droplets / mist created during atomization are collected. By atomizing the separation fluid, for example, using a nozzle or similar device, a separation fluid aerosol or mist can be generated with a comparatively large contact surface per unit volume of separation fluid.This allows for very effective mixing of the extracted dust-laden air with the separation liquid, while at the same time only a comparatively low pressure must be overcome to pass the extracted air through the separation device. However, it is important that, after mixing with the extracted dust-laden air, at least a predominant portion of the atomized separation liquid is separated from the air within the separation device and combined into a common liquid volume. To this end, it can be provided that, particularly downstream of the atomization device, deflection devices and / or flow obstacles, such as grid structures, baffles, etc., are present within the separation device, along which the mixture of atomized separation liquid and air is guided for the purpose of separating the separation liquid.

[0021] Ideally, the separation fluid should be drawn from the separation fluid reservoir to atomize the separating fluid, thereby supplying the separating fluid to the atomization device. This eliminates the need for constantly fresh separation fluid throughout the process, but rather creates a cycle in which the separation fluid can be repeatedly reused for re-atomization. In this case, it is particularly advantageous to filter the separation fluid at least locally, especially at the extraction point, before or when it is drawn from the separation fluid reservoir and fed to the atomization device, in order to better ensure the functional integrity of the atomization device.

[0022] In addition to or as an alternative to the above-described atomization of the separation liquid, it can also be provided that the extracted dust-laden air is fed directly into a liquid volume of the separation liquid via the extraction air supply. In this further development of the method according to the invention, a continuous liquid volume of the separation liquid is thus present, into which the extracted dust-laden air is blown and thereby mixed with the separation liquid. For this further development of the method, it can further be provided that the stream of extracted dust-laden air blown into the separation liquid is passed through a plurality of transfer openings into the separation liquid upon passing into the separation liquid, for example to achieve finer and more uniform bubble formation of the introduced air stream within the separation liquid.In addition or alternatively, it may be provided that the air within the volume of separation liquid is guided through the volume of separation liquid by means of deflection devices and / or flow obstacles, such as grid structures, baffles, etc., in order to extend the contact time between the air and the separation liquid and / or to enable improved bubble formation.

[0023] During operation, the amount of dust absorbed in the separation liquid will continue to increase over time. However, it can be advantageous for the separation process itself if the portion of the separation liquid that is currently in contact with the extracted dust-laden air is comparatively lightly laden with dust particles. It can therefore be advantageous if, during the ongoing process, the dust particles absorbed by the separation liquid are collected or concentrated locally within the total volume of separation liquid. This is possible, for example, if the dust particles absorbed within the separation liquid are concentrated and / or separated within the separation system using a separation device. This can be achieved, for example, by specifically exploiting sedimentation effects of the dust particles within the separation liquid through flow-calmed zones or similar.Depending on the extent and specific appearance of the dust particles within the separation liquid, dust sludge can, for example, be created and collected in one or more areas of the separation device.

[0024] It can be provided that the removal of dust-containing separation liquid and / or dust sludge accumulated in the separation device from the separation device takes place with the aid of a transport device. This can take place during the ongoing milling process or, for example, during an interruption in milling operation and / or during maintenance work. This can be done, for example, by suctioning the accumulated dust sludge out of the separation device using a suitable suction device, such as a suction pump, or by other means of conveying the dust sludge out, for example by means of a conveyor belt, in particular a continuous conveyor in the form of a scraper floor, a bucket chain or the like. Opening a drain opening through which dust sludge can be drained from the separation device, in particular by gravity, is also possible for the removal of the dust sludge.Finally, a dust sludge collection container can also be removed from the separation system.

[0025] It is further preferred if the removal of dust-containing separation fluid, and in particular dust sludge, is carried out in such a way that it reaches a transport device for milled material of the machine, or the milling bed, or the area of ​​the soil milling machine in front of the milling drum and yet to be milled. This allows the dust sludge to be transported away and loaded together with the milled material using the transport device for the milled material, or to be picked up by, for example, a sweeper following sooner or later behind the soil milling machine and cleaning the milling bed.

[0026] There are operating situations in which it is desirable to replace the separation fluid, for example as part of routine maintenance work, for transport purposes, or even for disposal purposes, particularly when the soil milling machine is milling contaminated soil and dust is generated in the process that requires separate disposal. Changing the separation fluid can be done, for example, by draining the separation fluid from the soil milling machine and refilling it with fresh separation fluid. Alternatively, however, it can also be provided that changing the separation fluid takes place by removing a separation module in which the separation fluid is stored from a base machine of the soil milling machine and by adding another separation module to the base machine, wherein the separation module in each case comprises at least part of the separation chamber, in particular the separation fluid reservoir.This can, for example, also be a standardized industrial container for liquids. In this case, the soil milling machine can have suitable detachable and connectable connecting lines for extracted dust-laden and / or purified air, for separation liquid and / or for energy, in particular electrical and / or hydraulic energy, in order to be able to establish corresponding detachable transmission connections between the base machine and the separation module, in particular via quick-release couplings. It can also be provided that the separation module is supplied with energy by means of a power supply that is autonomous from the base machine, in particular carried by the separation module. Additionally or alternatively, it is also possible for the base machine to carry at least part of the separation device by means of a trailer pulled by the base machine, in particular comprising the separation liquid reservoir.The replaceable separation module can comprise the complete separation device or only a part thereof, in particular only the separation liquid reservoir or a part thereof.

[0027] The commissioning of the method according to the invention can be optimized by triggering a starting pressure pulse for commissioning the separation device upon activation or upon the commencement of the introduction of extracted dust-laden air into the separation device. The maximum pressure at an extraction air supply to the separation chamber is greater than the pressure at the extraction air supply generated by an extraction fan during normal operation. This achieves a type of boost effect, which can be used in particular to counteract any initially existing flow resistance, such as that which may arise, for example, due to a substantially static volume of the separation fluid within the intended flow path of the extracted air within the extraction air duct.

[0028] In order to be able to monitor the operation of the separation device, it can be provided that at least one process parameter is recorded during the implementation of the method, in particular by means of one or more suitable sensors. This can, for example, be the recording and / or monitoring of a fill level of the separation liquid and / or an accumulation of dust sludge and / or a degree of contamination of the separation liquid. Specifically, suitable particle sensors and / or turbidity sensors can be used for this purpose. Additionally or alternatively, dust emissions from the soil milling machine during milling operation, in particular in the area of ​​the milling drum box and / or at a discharge point of the soil milling machine, at which milled material is transferred from the soil milling machine to a transport vehicle, for example, can also be recorded, for example by means of suitable emission sensors.It is also possible to monitor and / or record a pressure and / or a pressure difference within the separation device, in particular downstream of the extraction fan and / or at the extraction air supply and / or at the extraction air outlet and / or at the blow-off location, as well as, for example, the speed of a fan drive. The recording and monitoring of the travel speed and / or the milling depth of the soil milling machine is also possible. In addition or alternatively, the closed state of a cleaning opening can be monitored, through which, when open, separation fluid can be drained from the separation device. The load consumption and / or current consumption of a consumer, for example a drive of the extraction device, in particular a fan drive, or similar, can also be determined and monitored.

[0029] It is possible to control the operation of the separation device alone between an activated and a deactivated state. However, it may be advantageous, for example for reasons of efficiency, if at least one operating variable of the separation device and / or a component of the ground milling machine associated with the operation of the separation device is controlled during the implementation of the method. This makes it possible to adapt the operation of the separation device to the respective operating conditions in an optimized manner. The control can take place as a function of one or more operating variables or process parameters associated with the milling and / or extraction process, for example one or more of the process parameters recorded above. In concrete terms, this can include, for example, controlling the suction power of the extraction device, in particular of an extraction fan.This can be achieved, for example, by controlling the fan speed of the extraction fan and / or by controlling the currently available extraction cross-sectional area of ​​an extraction opening. This can, for example, change the volume flow of sucked-in dust-laden air supplied to the separation device and adapt it to the operating conditions. If, for example, it becomes apparent during ongoing milling operation that the current dust emissions from the floor milling machine are still too high, the suction power of the extraction device can be increased and vice versa. In addition or alternatively, the flow rate of a pump conveying the separation fluid, for example a recirculation pump that transports the separation fluid to an atomization device, can be varied. The operation of the transport device, which can be used to remove dust and dust sludge accumulated in the separation device, can also be controlled and regulated in this way.

[0030] A further aspect of the invention relates to a self-propelled soil milling machine, in particular a road milling machine, recycler, or stabilizer, for milling an area of ​​a soil surface to a milling depth. A soil milling machine of this type comprises a machine frame supported by driving devices, for example, wheels and / or crawler tracks, and having a drive motor. The drive motor, for example, an internal combustion engine, a hybrid engine, an electric motor, etc., can provide the drive energy required for the driving and working operation of the soil milling machine. A soil milling machine of this type further comprises a milling drum rotatably mounted in a milling drum box arranged on the machine frame for milling the area of ​​the soil surface.Furthermore, an extraction device is provided for extracting dust-laden air from the milling drum housing and / or an area of ​​a milling material conveying duct adjoining the milling drum housing, via which milling material milled from the ground surface can be conveyed from the milling drum housing to a discharge point. Such an extraction device comprises an extraction air duct extending from an extraction point, at which the dust-laden air is extracted from the milling drum housing and / or the area of ​​the milling material conveying duct adjoining the milling drum housing, to a blow-off point through which the extracted air can exit the ground milling machine. The extraction device also includes an extraction fan, via which the desired extraction of the dust-laden air takes place and which can also be the main driving force for passing the extracted dust-laden air through the separation device.

[0031] According to the invention, the extraction air duct comprises a separation device with a separation chamber designed separately from the milling material conveying channel, in which a separation liquid for separating dust from the extracted dust-laden air is present or stored. The separation chamber thus refers to a spatial compartment designed spatially separate from the milling material conveying channel, in which the separation process of dust particles from the extracted dust-laden air, as already described above, takes place with the aid of the separation liquid. For this purpose, the separation chamber is provided with an extraction air supply designed such that the extracted dust-laden air enters the separation chamber via it. The extraction air supply thus functionally essentially refers to a supply connection or opening through which the extracted dust-laden air is fed to the separation chamber and enters the separation chamber.Also part of the separation chamber downstream of the extraction air supply is a separation section designed such that the dust-laden air comes into contact with the separation liquid, thereby separating dust from the supplied dust-laden air and absorbing it into the separation liquid. The separation section thus refers to a spatial contact area in which the separation liquid comes into contact with the extracted dust-laden air, in particular is mixed, and in the process, dust particles contained in the extracted dust-laden air pass from the air into the separation liquid. In relation to the entire extraction air flow from the extraction point to the blow-off point, the separation section thus refers to the section in which the dust particles change from the air phase to the liquid phase of the separation liquid.Downstream of the separation section, the separation chamber comprises an exhaust air outlet designed to allow purified, extracted air to exit the separation device. The exhaust air outlet thus essentially functionally refers to a discharge connection through which the extracted and then purified, or at least dust-reduced, air is led out of the separation chamber or separation device and then further to the blow-off point. Finally, part of the separation chamber is also a separation fluid reservoir. The separation fluid reservoir refers to a volume of space in which a volume of the separation fluid is accommodated. In the separation reservoir, the separation fluid is thus present as a liquid entity, particularly unatomized.It can now be provided that the aforementioned separation section is located in the separation fluid reservoir, for example, if the extracted dust-laden air is introduced directly into the separation fluid, thus guiding this air through the separation reservoir, or if the separation fluid reservoir is designed separately from the separation section, as will be explained in more detail below, for example, if the separation fluid is atomized to essentially capture the dust. Mixed forms are also conceivable. During ongoing milling and extraction operations, separation fluid, which has been captured from the supplied dust-laden air, is collected and / or stored in the separation fluid reservoir.This inventive ground milling machine thus makes it possible to bind the dust present in the dust-laden air in the separation fluid, collect it with the ground milling machine during ongoing milling operation, and transport it along with the ground milling machine, at least temporarily. This allows, for example, the overall capacity of the separation system for collecting dust to be significantly increased compared to conventional extraction systems for ground milling machines, provided sufficient volumes of separation fluid are available.

[0032] Although alternative arrangements are possible, it is preferred if the extraction fan is arranged upstream of the separation device, i.e., in particular in the air flow direction between the extraction location and the separation section. In this way, the extraction fan forces the extracted dust-laden air through the separation device. However, it is also possible, for example, for the extraction fan to be arranged downstream, i.e., behind the separation section in the air flow direction, so that in this case the extracted air is drawn through the separation section. A combination of several extraction fans, arranged in series and / or in parallel, is also possible.

[0033] A pre-separator can be arranged in the extraction air duct upstream of the separation section, and in particular upstream of the extraction fan. The task of the pre-separator is to separate larger particles, such as small stones, from the dust-laden air stream compared to the dust being separated by the separation device. This can prevent these particles from entering the separation device itself and causing damage and / or defects. A centrifugal separator, in particular a cyclone separator, or an inertial separator can be used as a pre-separator. Filter-like structures, such as a wire mesh, are also conceivable.

[0034] It may be advantageous if the extraction device downstream of the separation section in the extraction air duct has a device for separating droplets of separation fluid from the purified extracted air. Such droplets can be entrained by the air flow within the extraction air duct, particularly downstream of the separation device. A droplet separator, e.g., a centrifugal separator such as a cyclone separator, a lamella separator, a wire mesh separator, etc., can be used for this purpose.

[0035] In principle, it is also possible to provide one or more additional devices downstream of the separation device for separating and / or binding residual dust particles present in the extracted air that has already passed through the separation device, in order to further reduce the dust content in the air discharged from the soil milling machine at the discharge point. The use of centrifugal separators or inertial separators, but especially electrostatic precipitators, has proven particularly suitable for this purpose. More than one separation device with a separation fluid can also be functionally arranged in series or parallel to one another.

[0036] With regard to the specific design of the separation section, it is possible, for example, for the separation device to comprise an atomizing device. The task of the atomizing device is to atomize or divide the separation liquid into droplets, for example into a mist, and / or into one or more liquid curtains in order to thereby create a comparatively large contact surface for the separation liquid. For this purpose, the atomizing device can, for example, comprise one or more nozzles for generating a droplet mist and a fluid pump for supplying the at least one nozzle with separation liquid. The drops / mist of the separation liquid are then collected and combined in the separation liquid reservoir or towards it, for example driven by gravity.The temporarily atomized separation fluid thus remains within the soil milling machine, in particular within the separation device, and most particularly within the separation chamber. It is possible for the separation section to extend exclusively through an area with atomized separation fluid. Alternatively, however, the separation section can also extend into the separation fluid reservoir, in particular downstream of that part of the separation section in which the separation fluid is present in the form of droplets. In this embodiment, the extracted dust-laden air thus first passes, for example, through a droplet mist of the separation fluid and then through a total liquid volume of the separation fluid.

[0037] If the separation device comprises an atomization device of the above type, the separation device is preferably designed such that the separation fluid supplied to the atomization device is drawn from the separation fluid reservoir by means of a recirculation pump. For the separation process, fresh separation fluid is thus not constantly supplied to the separation device from the outside; rather, a circulating process is provided in which separation fluid accumulating downstream of the separation section is repeatedly fed from the separation fluid reservoir to the atomization device by the recirculation pump.At the point at which the separation liquid is withdrawn from the separation liquid reservoir by the recirculation pump, which is preferably designed as a paddle wheel pump, for example, a separation and / or filter device is preferably present and / or the withdrawal takes place in an area in the separation liquid reservoir in which, for example, mechanically acting flow obstacles facilitate sedimentation of dust particles dispersed in the separation liquid in order to ensure that the recirculated separation liquid has a comparatively low degree of contamination with dust particles.The recirculation pump can further be designed and arranged within the separation device in such a way that, in particular during milling operation and / or in a maintenance mode, at least part of the separation liquid present in the separation device, in particular from the separation liquid reservoir, can be pumped out.

[0038] It is also possible for the extraction air supply to be designed in such a way that the extracted dust-laden air is directed directly into a liquid volume of the separation liquid within the separation chamber. For this purpose, the extraction air duct, in particular the extraction air supply, can include a dip tube whose outlet opening ends in a fluid volume of the separation liquid. For the operation of the separation device, it is then particularly provided that the extracted dust-laden air is blown directly into the liquid volume of the separation liquid.

[0039] For this process, it can be advantageous if the extraction air supply has a plurality of outlet openings through which the extracted dust-laden air is directed directly into the liquid volume of the separation fluid. This allows for finer bubble formation of the extracted dust-laden air in the separation fluid, enabling improved separation results. For this purpose, the extraction air supply can comprise a perforated grille or similar device.

[0040] The separation liquid present in the separation liquid reservoir in the soil milling machine can have a considerable volume, in particular comprising at least 200L, very particularly even comprising at least 400L of separation liquid, in particular water.

[0041] The separation fluid volume can be provided in addition to a water tank on the ground milling machine, which is designed to hold water that is applied during the ongoing milling process into the milling drum box, onto the milled material located in a conveyor channel, etc., outside the separation device and thus consumed during the ongoing milling process, for example by means of a sprinkler system. The separation device, as described here, can be operated, in particular completely, independently of the sprinkler system. In particular, it can be provided that the separation fluid of the separation device is used and applied completely separately from the water stored in the water tank for the sprinkler system during the ongoing process.

[0042] It can be provided that the separation device, in particular the separation fluid reservoir, has one or more baffles. This can reduce externally induced movements of the separation fluid within the separation device. Additionally or alternatively, at least part of the separation device, in particular at least the separation fluid reservoir, can be mounted in a vibration-damped manner relative to the machine frame of the soil milling machine, in particular via suitable damping mounts that connect the separation device or at least the separation fluid reservoir to the rest of the machine. This can, for example, reduce the transmission of movements of the separation fluid within the separation device to the rest of the soil milling machine and vice versa.

[0043] One factor that can influence the separation rate of dust from the extracted dust-laden air into the separation liquid is the contact time available within the separation section between the extracted dust-laden air and the separation liquid and / or the length of the separation section. In order to optimize the separation rate, a deflection device can be provided within the separation liquid reservoir, which is designed such that it extends the path of the air dispersed in the separation liquid volume from the extraction air supply to the outlet from the separation liquid volume. The deflection device can, for example, be designed as a deflection surface that represents an obstacle in the vertical direction for bubbles of the extracted dust-laden air rising in the separation liquid.To enable targeted guidance of the bubbles in a horizontal direction, the deflection surface can be positioned at an angle or incline relative to the horizontal within the separation section. The deflection device can additionally or alternatively be designed as an element that breaks up the air bubbles, for example, in the form of a plurality of through-holes, specifically as perforated sheet metal, wire mesh, or similar.

[0044] One function of the present separation device is to bind the dust absorbed in the separation fluid and collect it during the ongoing milling process. However, this can be disadvantageous if the dust particles present in the separation fluid are evenly distributed throughout the entire volume of separation fluid. Rather, it is preferred if a separation device is present within the separation device, which is designed such that dust particles absorbed within the separation fluid are locally concentrated and / or separated from the separation fluid. This can be achieved, in particular, by utilizing the sedimentation effects of the dust particles within the separation fluid.Specifically, the design of the separation fluid reservoir can, for example, create targeted, movement-reduced zones, for example, by means of wall structures that extend at least partially vertically, particularly from an interior floor, or by means of risers, etc. In these areas, dust particles can accumulate and concentrate within the separation system, for example, forming a dust sludge over time. This removes these dust components from the separation fluid and removes them from the remaining separation process.

[0045] A transport device may be provided which is designed such that dust-containing separation liquid and / or dust sludge accumulated in the separation device can be removed from the separation device. This may be a pump, in particular a paddle wheel pump, or also a continuous conveyor, for example in the form of a bucket chain and / or a scraper floor. An openable and closable outlet may also be provided, through which separation liquid together with, for example, dust sludge can be drained from the separation device by gravity. For this purpose, a conical base region may be included in the separation liquid reservoir, the outlet opening being located at the conical tip located at the bottom in the vertical direction.The outlet can be designed with respect to its opening towards the outside environment of the soil milling machine in such a way that the material emerging from it falls or is directed onto a soil area in the working direction of the soil milling machine in front of or behind the milling drum, into the milling drum box or onto an area of ​​the conveyor device for the milled material of the soil milling machine.

[0046] The separation device can comprise a flushing device for cleaning at least part of the separation device, in particular for flushing dust sludge from the interior of the separation device to an exterior of the ground milling machine. Such a flushing device can comprise one or more fluid outlets, in particular in the form of fluid nozzles, which are arranged at locations to be cleaned within the separation device. It is preferred if the fluid supply to the flushing device comes either from an additional water tank of the ground milling machine, for example a water tank in which the water used for milling operation to cool the chisel is stored, or from outside the ground milling machine, for example via a tank truck and / or a hydrant. The flushing device can preferably also be used to fill the separation device with separation fluid from outside the separation device.The flushing device may comprise a pump carried by the soil milling machine. This may, for example, also be the recirculation pump, which may have a suitable valve device for switching between recirculation mode, flushing mode, and / or a pumping mode in which separation fluid is pumped out of the separation device.

[0047] For certain application situations, it may be advantageous if the separation device has a removal module that can be removed from outside a base machine of the soil milling machine, wherein the removal module is designed to receive dust-containing separation fluid and / or accumulated dust sludge during operation of the separation device. The base machine thus refers to the soil milling machine at least without the removal module, in particular without the separation fluid reservoir. It can also be provided that practically the entire separation device, possibly except for suitable connection points, is encompassed by the removal module. The removal module refers to an assembly that is intended for repeated attachment to and removal from the base machine, in particular also in the field. The removal module itself can also comprise several sub-modules. In particular, it can be provided that the removal module comprises at least the separation fluid reservoir.The removal module can be at least partially designed as reusable transport packaging in the form of a plastic tank. Such containers are often standardized and thus quickly and inexpensively available. Furthermore, they are easy to handle for disposal purposes. The base machine can have suitable fixing devices with which the removal module, when installed in the base machine, is held stationary relative to the rest of the soil milling machine. Suitable guidance devices, such as guide rails, etc., can be provided to repeatedly move the removal module to a defined position within the soil milling machine.

[0048] In the event that at least part of the separation device, in particular the separation liquid reservoir, is designed as a removal module, the removal module can be carried by the machine frame of the base machine when installed or can be positioned on a trailer pulled by the base machine. This trailer solution has the particular advantage that considerably larger volumes of separation liquid can be carried and / or retrofitting a conventional soil milling machine with the separation device is comparatively simple. Positioning the removal module on the machine frame of the base machine in such a way that the removal module is carried by the machine frame, in turn, has the advantage that the additional weight caused by the removal module can be beneficial for the milling process itself and, under certain circumstances, enables faster milling work.The trailer solution also clearly states that the power supply for the separation system can, but does not have to, be independent of the base machine. Furthermore, suitable connecting lines can be provided for the extracted dust-laden and / or purified air, for the separation fluid, for the power supply, for the transmission of sensor signals and / or control commands, particularly in the form of suitable quick-connect and / or multi-couplings.

[0049] The self-propelled ground milling machine is preferably designed to carry out the method according to the invention. The contents disclosed for the method according to the invention therefore also extend to the ground milling machine according to the invention, and vice versa. The ground milling machine according to the invention can, for example, have a suitably designed control device for this purpose.

[0050] Even if, in the simplest case, the operation of the separation device alone can be switched between an activated and a deactivated state, it can be advantageous if the soil milling machine has a control device which is particularly designed to control one or more operating parameters of the soil milling machine and in particular of the suction device. These can be, for example, the speed of a fan drive of the suction blower and / or the suction power of the suction device. Additionally or alternatively, it can also be provided that it controls a delivery rate of a pump conveying the separation liquid, for example the recirculation pump, the operation of a transport device, as described above, etc. This makes it possible to vary the operation of the suction device, in particular depending on the situation, and to adapt it in an optimized manner to the current operating conditions.

[0051] It can therefore be provided that the soil milling machine comprises a sensor device designed to detect at least one process parameter. The at least one process or operating parameter can be used to control the operation of the separation device in a regulated manner and / or at least to inform the operator about one or more operating states. The sensor device can thus be designed, for example, to detect a fill level of the separation liquid, for example by means of a suitable fill level sensor, a degree of contamination of the separation liquid, an amount of accumulated dust sludge, or a current dust emission of the soil milling machine during milling operation. It can also be provided to detect the pressure within the separation device, in particular downstream of the extraction fan and / or at the extraction air supply and / or at the extraction air outlet and / or at the blow-off location, by means of one or more pressure sensors.In particular, the determination of a suction power of the extraction device, a speed of a fan drive, a position of an air supply opening, etc. can also be provided. The actual detection of one or more of these process parameters can be carried out via one or more sensors known per se in the prior art, which are connected to the control device via a suitable signal transmission connection.

[0052] The invention is explained in more detail below with reference to the exemplary embodiments shown in the figures. They show schematically: Figure 1: a side view of a soil milling machine in a work train with a transport vehicle; Figure 2: a further schematic view of a soil milling machine with a suction device; Figure 3: a second embodiment of a suction device; Figure 4: a third embodiment of a suction device; Figure 5: a soil milling machine with a removal module; Figure 6: a soil milling machine with a transport device; Figure 7: a soil milling machine with a replaceable separating liquid reservoir; Figure 8: a soil milling machine with a base machine and a trailer; Figure 9: a soil milling machine with a suction device and a control device; and Figure 10: a flow diagram of a method.

[0053] Identical or functionally identical components are designated by the same reference numerals in the figures. Recurring components are not necessarily designated separately in each figure.

[0054] Figur 1 shows a work train comprising a soil milling machine 1, here a road milling machine, and a transport vehicle 2, specifically a truck in a typical application situation in which the soil milling machine mills soil material and loads it onto the transport vehicle 2 driving in front of the soil milling machine 1 in this case.

[0055] The soil milling machine 1 has a machine frame 3, which forms the essential supporting structure of the machine. The soil milling machine 1 can be operated from an operator's station 4, which can, for example, be partially open and / or closed or designed as a driver's cab. The machine frame 3 can be supported by front and rear travel devices 5, viewed in the working direction a. These can be designed as tracked or wheeled drives. Some or all of the travel devices 5 can be driven. The travel devices 5 can be mounted on the machine frame 3 via height-adjustable lifting devices 6, for example lifting columns. To provide the drive energy required for travel and milling operations, the soil milling machine 1 has a drive motor 7. This can, for example, be a diesel combustion engine or a comparable primary drive unit.The soil milling machine 1 has a milling device 8, the essential components of which are a milling tool, in the present case a milling drum (in . Fig. 1 not shown), as well as a milling drum box 10. The milling drum box 10 surrounds the milling tool to the sides and above and thus shields the working area of ​​the milling tool from the outside environment when it is working in the subsoil. The milling tool can be a milling drum comprising a substantially hollow-cylindrical support tube, on the outer surface of which a plurality of milling bits and / or similar milling tools are arranged. During milling operation of the soil milling machine 1, the milling drum engages the subsoil at a milling depth and, while the machine continues to advance in the working direction a, mills away subsoil material to the milling depth.This is collected in the interior of the milling drum box 10 and passes through a suitable outlet opening onto a milling material conveyor device 11 of the ground milling machine 1, with which the milled material is conveyed to a discharge point 14 on the side of the ground milling machine 1 and from there, for example, is discharged into the transport vehicle 2 for removal of the milled material. The milled material conveyor device 11 can, as in the present exemplary embodiment, have two conveyor units arranged in series, in this case an inner conveyor belt 12 and an outer conveyor belt 13, or it can only have one conveyor unit or more than two conveyor units. The ground milling machine therefore comprises a separate milling material conveyor line for the milled material from the milling drum box 10 to the discharge point 14. This conveyor line for the milled material can be partially surrounded or shielded by housing elements and can therefore form a substantially shaft- orhave a channel-like structure and is therefore also referred to as a milling material conveying channel 55. In particular for the inner conveyor belt 12, it is known to arrange this within a receiving shaft of the machine, so that parts of the machine frame and / or machine components surround a free space in which the inner conveyor belt and the milling material conveying section run. For the outer conveyor belt 13, it is known to arrange wall elements on the supporting frame of the outer conveyor belt in order to delimit the conveyor section to the outside. It is also possible for the milling material conveying device 11 not to be mounted on the ground milling machine 1 with its discharge point facing forward in the forward direction a, as in the present case, but to be additionally and / or alternatively directed to one side and / or backwards as seen in the working direction A.A transfer point can be provided between the inner conveyor belt 12 and the outer conveyor belt 13, at which the milled material is discharged from the inner conveyor belt 12 onto the outer conveyor belt 13 in the conveying direction. In the present embodiment, the milling device 8 is arranged in the working direction a between the front and rear driving devices 5. This type of soil milling machine is also referred to as a center-rotor milling machine. So-called rear-rotor milling machines are also known, in which the milling device is arranged between the two rear driving devices. The invention also extends to this type of soil milling machine.

[0056] Furthermore, so-called stabilizers and recyclers are known in the prior art as further types of soil milling machines. These can have a similar design. Stabilizers serve to mill the subsoil and mix it with a binding agent. Recyclers mill soil material and can also mix additives into the milled material. Stabilizers and recyclers comprise a milling device, but often no milled material conveying device, since the soil material they process usually remains on the soil surface. The invention also extends to these machines in the manner described, but, where not necessary, without the respective references to the milled material conveying device.

[0057] During milling operation of the ground milling machine 1, a significant amount of dust may be generated. This can be caused, in particular, by the milling action of the milling device 8 itself and / or the transport of the milled material along the milled material conveyor. Accordingly, dust-laden air can escape into the outside environment, particularly in the area of ​​the milling drum housing 10 and / or in the area of ​​the milled material conveyor device 11, particularly in the area of ​​the internal conveyor belt 12, and / or at the discharge point 14.

[0058] Soil milling machines 1 of the present type can have a water sprinkler device 15, with which water, in particular in the form of a spray, can be applied into the milling drum box interior, an area of ​​the milled material conveying path and / or in the area of ​​the discharge point, among other things to bind dust in dust-laden air. This can comprise a water tank 57 and / or a suitable piping and / or valve system 58. The water supplied from the water tank 57 via, for example, the piping system 58 ( Fig. 2 The water discharged into the milling drum housing via the water sprinkler system 15 can also be used to cool the milling tools. The dust reduction achieved with the water sprinkler system 15 is usually insufficient.

[0059] In order to reliably reduce dust emissions in the area of ​​the milling drum box 10 and the milled material conveyor section, the present ground milling machine 1 comprises a suction device 16. An exemplary suction device 16 of the ground milling machine 1 from Fig. 1 is in the Fig. 2 explained in more detail. It can comprise an extraction fan 17 or other suction device, via which dust-laden air can be extracted along an extraction air duct 18 from an area of ​​the milled material conveying device and / or the milling drum box 10. The extracted air is guided within the ground milling machine 1 along the extraction air duct 18 and up to a blow-off point 19, via which the extracted air exits the ground milling machine 1 into the outside environment. Regardless of the specific embodiment, the extraction fan can be a radial fan, for example. With the help of the extraction fan 17, a volume of air can be conveyed and thus a negative pressure and ultimately a suction effect can be generated on a suction side of the extraction fan 17.Via the extraction air duct 18, areas of the milled material conveyor line and / or the milling drum housing 10, especially its interior, can be incorporated into the suction effect generated by the extraction fan 17, such that dust-laden air present and / or generated there is conveyed from the extraction fan 17 to the extraction fan and downstream of the extraction fan 17 to the separation device 9, which will be described in more detail below. These areas are collectively referred to as the extraction location 20. The specific positioning of the extraction fan within the extraction air duct 18 can vary. For example, an arrangement downstream of the separation device 9 is also possible. The extraction air duct 18 thus designates the air duct section between the extraction area 20 of the milled material conveyor section and / or the milling drum box, from which dust-containing air is extracted to the extraction fan, up to the blow-off location 19.The suction air duct 18 can extend at least partially into the space of the milled material conveyor line. Fig. 2 The direction of the extracted air is illustrated in more detail with arrows. The extracted dust-laden air is indicated by dashed lines. The dust-reduced or purified air, in contrast, is shown with solid lines. The dotted arrow indicates the direction of sedimentation and separation of dust particles from the extracted dust-laden air by a separation fluid (AF), as explained in more detail below.

[0060] Part of the extraction air duct 18 is the separation device 9, or the extraction air duct 18 is designed such that the extracted dust-laden air is guided through the separation device 9 to the blow-off point 20. The separation device 8 comprises an extraction air supply 21 and an extraction air outlet 22. The extracted air is fed to the separation device 8 via the extraction air supply 21 and is then discharged again onto the separation device 8 via the extraction air outlet 22. A separation section 23 is provided within the separation device 8. In the area of ​​the separation section, the extracted dust-laden air comes into contact with the separation liquid AF and can mix with it. The separation section 23 thus designates a defined spatial compartment, ora separation chamber in which, when the separation device 8 is used as intended, these processes take place, and dust particles contained in the dust-laden air can be transferred into the separation fluid. For receiving and storing the separation fluid AF, the separation device 8 also includes a separation fluid reservoir 24. The separation fluid reservoir refers to a spatial compartment in which the separation fluid AF is stored as a liquid volume.

[0061] The principle of the invention consists in mixing the extracted dust-laden air with the separation fluid AF, thereby separating dust particles from the dust-laden air and absorbing them in the separation fluid, particularly by enriching them there throughout the milling operation and thereby removing them from the air flow of the extracted dust-laden air. The separation fluid is intended to remain at least substantially in the floor milling machine 1 throughout a milling operation and thus not be consumed during this process, unlike, for example, the water for bit cooling from the water tank 57 of the sprinkler system 15.

[0062] One way to achieve the mixing of the separation liquid with the extracted dust-laden air is in the Fig. 2 illustrated in more detail. In this embodiment, the separation section 23 is located in the separation liquid reservoir 24. For mixing, the extracted dust-laden air is discharged downstream of the suction fan 17 via a dip tube 25 directly into the liquid volume of the separation liquid. The fill level FS of the separation liquid reservoir is shown in the Fig. 2 indicated by FS. The outlet opening 26 of the immersion tube 25 is thus located below the surface of the separation liquid at the fill level FS. The air bubbles created upon exiting rise within the separation liquid. One or more deflection devices 28 can be provided in this path, for example in the form of deflection plates, perforated plates, etc. The now cleaned or at least dust-reduced air is led out of the separation device 9 via the suction air outlet 22. The dust particles separated from the air, as well as the separation liquid itself, remain within the separation device. Depending on the type and size of the dust particles and / or the separation liquid, this can lead to sedimentation of dust particles and thus to the formation of dust sludge SL within the separation device 8.This process of local concentration of the dust present in the separation liquid AF may indeed be desirable and may be further promoted, for example, by a separation device 27 within the separation device 8. The separation device 27 may, for example, be elements that reduce movements within the separation liquid AF, as in the figure shown in FIG. Fig. 2 In the embodiment shown, for example, wall elements or the like protrude from the bottom of the separating liquid reservoir 24. The dip tube 25 can have a plurality of openings at its outlet end, for example, formed by a perforated plate or the like.

[0063] Within the separation liquid reservoir 24, regardless of the specific embodiment or specific exemplary embodiment, a mixing device, in particular a mechanical mixing device, for example in the form of a stirrer and / or a circulating pump, can be provided in order to improve and / or facilitate the absorption of dust particles in the separation liquid and / or the passage of the extracted dust-laden air through the separation liquid. Fig. 2 A stirrer 59 is given as an example.

[0064] In order to keep losses in the total volume of separation liquid AF available within the separation device 8 as low as possible during the ongoing operation of the separation device 8, it may be advantageous if a device for separating liquid droplets from the air flow guided in the suction air guide 18 is provided downstream of the separation section 23, such as the device shown in the Fig. 2 shown droplet separator 29. This can be connected to the separation device 8 by a return line 30, so that portions of separation liquid separated from the air can be fed back to the separation liquid reservoir 24.

[0065] Additionally or alternatively, it can be provided that upstream of the separation device 8 one or more pre-separators 31 are included in the extraction air duct 18, for example in the form of grid structures through which the extracted dust-containing air flows, centrifugal or inertial separators, etc. With the help of these pre-separators 31, it can be prevented, for example, that comparatively coarse particles reach the separation device 8.

[0066] One or more baffles 60 may be provided within the separating liquid reservoirs 24 to counteract sloshing effects of the separating liquid. It is possible for the deflection devices 28 to also simultaneously function as a baffle.

[0067] Fig. 3 illustrates an alternative design of the separation device 9 in several respects. In this embodiment, the separation device 9 comprises an atomizing device 31. The task of the atomizing device 31 is to increase the contact surface of the separation liquid. For this purpose, the atomizing device can, for example, be designed such that it has one or more outlet openings for the separation liquid, which create a flowing curtain of separation liquid through which the extracted dust-laden air flows. Additionally or alternatively, the atomizing device can also have one or more nozzles 32, in particular spray nozzles, with which a nebulization or atomization of the separation liquid takes place within the separation device. In the embodiment according to Fig. 3 The nozzles 32 can be supplied with separating fluid individually or via a common spray bar 33. The nozzles can be designed such that they can be opened and closed as a whole, in groups, or individually. A pump 34 can be provided to supply the nozzles 32 with separating fluid. The pump 34 can convey separating fluid to the outlet elements of the atomization device 31, for example, the nozzles 32, via a line connection system.

[0068] For this purpose, it can be provided that the pump 34 delivers separating liquid from an additional and separate storage volume of separating liquid. However, it is preferred if the pump 34 takes separating liquid from the separating liquid reservoir 24, as in the Fig. 3 This creates a circulating process in which the separation fluid atomized by the atomizing device 31 is first passed through the separation section 23, where it collects dust particles from the extracted dust-laden air. The atomized separation fluid is then recombined into a coherent fluid volume and flows into the separation fluid reservoir 24. From there, it can be removed by means of the pump 34 and fed back into the atomizing device 31. This circulating process, in which the pump 34 thus acts as a recirculation pump, leads, over the ongoing milling operation, to dust particles being continually enriched in a practically defined and constant volume of separation fluid and remaining in the soil milling machine or being collected there.It is advantageous if a separation and / or filter device 35 is present at the point of withdrawal of the pump 34 from the separation liquid reservoir 24 and / or if the withdrawal takes place in an area in the separation liquid reservoir 24 in which, for example, mechanically acting flow obstacles reduce sedimentation and accumulation of dust particles dispersed in the separation liquid, in order to ensure that the pump withdraws the separation liquid from the separation liquid reservoir 24 with a comparatively low degree of contamination.

[0069] With regard to the mixing of the extracted dust-containing air with the separation liquid in the separation section 23, it can be provided that this takes place in an area in which the separation liquid is atomized, as is the case, for example, in the areas 23a and 23b of the separation section in the embodiment according to Fig. 3 This is the case. It is possible to operate the extracted dust-laden air relative to the spray direction of the atomizing device 31 in cocurrent operation, such as in the area of ​​the separation section 23a, or in countercurrent operation, such as in the area of ​​the separation section 23b. In the embodiment according to Fig. 3 For example, if the level of the separation liquid is at level FS, the mixing between the extracted air and the separation liquid occurs almost exclusively in the area 23a and 23b of the separation section.

[0070] To extend the path of the extracted air through the separation device 8, an air guide device 36 is provided, for example in the form of a flow guide wall, which deflects the extracted dust-laden air within the separation device 8 and thereby extends the separation path 23 between the extraction air supply 21 and the extraction air outlet 22 as a whole. It is understood that the specific design of this air guide device 36 can be varied in many ways and, for example, can also have a plurality of flow deflections or the like.

[0071] If the fill level in the present embodiment is at FS', the extracted dust-laden air must be guided directly through the volume of separation liquid due to the air guiding device 36 then extending into the separation liquid. Thus, regardless of the specific embodiment, the separation section 23 can also comprise, in addition to the regions 23a and / or 23b, a region 23c in which the dust-laden air is mixed not with atomized separation liquid, but also with the coherent liquid volume of the separation liquid. In this case, the separation section 23 thus comprises at least two regions in which the separation liquid is present in different forms for mixing with the extracted dust-laden air, in this case, for example, as mist and as a coherent liquid volume.

[0072] The separating device 8 can be a separate one from the separating liquid reservoir, such as in the Figuren 2 and 3 shown, formed separating device 27. In the Fig. 3 For this purpose, a separation device 27 is shown, which has a plurality of settling stages acting in series to promote sedimentation processes of dust particles dispersed in the separation liquid. For this purpose, a connecting line 37 is provided, via which separation liquid is withdrawn from the region of the separation section (or another region of the separation device 8), for example, also with a separate pump, and fed into the separation device 27. Provision can be made for the separation liquid accumulating on a clean side of this separation device 27 to be fed to the separation section 23 by a pump 34.

[0073] The separation device can comprise a flushing device 61, for example, to clean the separation device 9 itself or at least parts thereof. The flushing device 61 can be supplied with a cleaning fluid from outside the soil milling machine, from the water tank 52, or even from the separation fluid volume. For this purpose, for example, the pump 34 or 34' or a separate pump can be used. One or more valve devices can be provided to enable these multiple functions of the respective pumps.

[0074] The embodiment according to the Fig. 4 illustrates, in particular, an alternative embodiment of an air guiding device 36 within the separation device 9. For example, a total of several labyrinth-like wall elements 36a to 36d can be provided. The separation section 23 is designed such that the extracted dust-laden air is guided several times, specifically, for example, three times, successively through the volume of separation liquid between the extraction air supply 21 and the extraction air outlet 22.

[0075] Fig. 4 further illustrates an alternative design of the dip tube 25 or the outlet opening 26. In this embodiment, the outlet opening 26 comprises a plurality of openings. In this way, the formation of finer bubbles of the extracted dust-laden air within the separation liquid can be induced. Additionally or alternatively, swirling elements and / or diffusers 38 can be provided in the region of the outlet opening 26. These can improve the mixing process between the extracted dust-laden air exiting into the separation liquid and the separation liquid.

[0076] The Figuren 5, 6, 7 und 8 each show a floor milling machine 1 in side view.

[0077] In the embodiment according to Fig. 5 The separating device 9 is designed in the form of a removal module 39, which as a whole is designed in such a way that it is designed for repeated attachment and detachment to / from a base machine 40 (ie the soil milling machine without the removal module). The separating device 9 can thus be removed as a whole, for example by means of a forklift or the like, and handled separately from the base machine, for example for maintenance, transport and / or disposal purposes (in the Fig. 5 This is illustrated by the removed separator device 9'. With such a removal, for example, the separating fluid on the ground milling machine can also be changed. The base machine 40 and / or the removal module 39 can have means to facilitate this changeover process, for example, a guide device for the defined positioning and / or fixing of the removal module 39 in / on the base machine, easily detachable and closable connection interfaces for connecting and disconnecting energy and / or signal and / or air supply and / or separating fluid supply connections.

[0078] A part of the separation device 9, in particular the removal module 39, can be mounted in a vibration-damped manner relative to the machine frame 3 of the soil milling machine 1 via suitable damping bearings 59.

[0079] In the embodiment according to the Fig. 6 The separation device 9 comprises a transport device 42, for example in the form of a continuous conveyor or the like. The transport device 42 is intended to convey dust particles collected in the separation device 9, for example in the form of dust sludge, out of the separation device. For this purpose, it can be provided that the transport device 42 conveys onto the milled material conveying device 11. Additionally or alternatively, the transport device 42 can also be designed such that it conveys into the milling device 8 and / or onto a floor area that lies in front of or behind the milling device 8 in the working direction a, for example into the milling bed created during the work process or onto the floor area still to be milled.

[0080] For removing accumulated dust, in particular dust sludge, in the separating device 9, in particular within the separating liquid reservoir 24, an outlet 58, such as in the Fig. 3 shown. Additionally or alternatively, pump 34 can also be used to pump out dust sludge.

[0081] The embodiment according to the Fig. 7 is characterized in that in this case, it is not the separation device 9 itself that is designed as a removal module 39, but only a part of the separation device 9, in particular, for example, the separation liquid reservoir 24 or at least a part thereof. This can be designed as a type of tank element, for example also in the form of a standardized industrial container. It is understood that here too, the base machine 40 and / or the removal module 39 can have means that facilitate the changeover process, for example guide devices for the defined positioning and / or fixing of the removal module 39 in / on the base machine, easily detachable and closable connection interfaces for connecting and detaching energy and / or signal and / or air guide and / or separation liquid guide connections.This embodiment is particularly suitable for milling soils contaminated with problematic substances that require separate disposal. In this case, the equally contaminated dust can be bound and transported separately from the base machine 40 in a specially designed container. In this case, the easily detachable and closable connection interfaces for connecting and disconnecting energy and / or signal and / or air and / or separating fluid supply connections can thus also be provided between the separating fluid reservoir 24 and the remaining separation device 9.

[0082] In the embodiment according to the Fig. 8 In addition to the base machine 40, the soil milling machine 1 comprises a trailer 41 pulled by the soil milling machine, on which at least essential parts of the separation device 9 are arranged. It can be provided that the extraction fan 17 is arranged on the base machine 40 and that a suitable transmission line 42 is provided for transferring the extracted dust-laden air from the base machine 40 to the trailer 41. However, the extraction fan can also be positioned on the trailer 4. A mechanical towing connection 43, for example in the form of a drawbar, can be provided separately from any existing power and / or signal and / or air supply and / or separation fluid supply connections, so that the trailer is pulled by the soil milling machine 1 and does not require its own drive.

[0083] It can be provided that an additional cooling water tank 44 is arranged on the trailer, which is connected to the base machine 40 via a cooling water connection line 45. In this way, the total volume of cooling water available for cooling the milling device 8 can be significantly increased, in particular in addition to a cooling water tank 57 arranged on the base machine 40. The cooling water pump 46 can be mounted on the base machine 40 (as in Fig. 8 shown) or also on the trailer 41.

[0084] The process of operating the separating device 9 can be partially monitored and / or, in particular, controlled. This is illustrated by the Fig. 9 examples of possible alternatives.

[0085] The soil milling machine 1 can comprise a control device 47. The control device 47 can control one or more components relevant to the operation of the separation device 9. This can be, for example, the operation of the suction device 16. For this purpose, it can be provided that the control device 47 controls the speed of a fan drive of the suction blower and / or other components via which the suction power of the suction device 16 can be varied. Additionally or alternatively, the control device 47 can, for example, control the pump 34 and thereby, depending on the embodiment, activate and / or deactivate the pump 34 and / or change the delivery rate of the pump 34. The operation of the transport device 42 can also be controlled by the control device 47. Furthermore, the control device 47 can additionally or alternatively also control other operating components of the soil milling machine 1.

[0086] During operation of the separation device 9, it can be advantageous, for example to control various components of the separation device 9 and / or to provide information to the operator of the soil milling machine 1, to have a sensor device 49 designed to detect at least one of the process or operating parameters relevant to the operation of the separation device. For this purpose, the sensor device 49 can comprise a plurality of sensors that are in signal transmission connection with the control device 7. This can be, for example, a fill level sensor 50 with which the fill level of the separation device 9 with separating liquid can be determined and / or monitored. Additionally or alternatively, a sensor 51 monitoring the extraction performance and / or operation of the extraction device can be provided, such as a speed sensor of a fan drive of the extraction fan 17.Furthermore, or alternatively, one or more sensors 52 may be provided which determine the dust loading state of the separation device, such as a sensor for determining a degree of contamination of the separation liquid, a sensor for determining the extent of accumulated sludge within the separation device, etc. Furthermore, or alternatively, it is possible for a sensor 53 to monitor the dust emission of the soil milling machine 1 during milling operation and / or a pressure sensor 54 to be provided, with which the pressure within one or more sections of the extraction air duct 18 can be determined and / or monitored.

[0087] It may be provided that the operation of the separation device is controlled depending on one or more process or operating parameters of the separation device and / or the soil milling machine 1. For this purpose, it may be provided that one or more of the measured values ​​determined by the sensor device 49 are used.

[0088] Fig. 10 Finally, the sequence of a method 56 for dust reduction during milling operation of a self-propelled ground milling machine (1), in particular a road milling machine, recycler, or stabilizer, is illustrated by way of example. The embodiments of the ground milling machine and its subcomponents explained above as examples are particularly suitable for implementing this method.

[0089] The method 56 comprises, in step a), performing a milling operation and driving over a ground surface. The ground milling machine is thus in milling mode. In step b), during the ongoing milling operation, dust-laden air is extracted from the milling drum box 10 and / or from a region of a milling material conveying channel 11 adjoining the milling drum box 10, via which milling material milled from the ground surface can be conveyed from the milling drum box to a discharge point, by means of a suction device 16. The suction device comprises an extraction air duct 18, which extends from an extraction location, at which the dust-laden air is extracted from the milling drum box 10 and / or from the region of the milling material conveying channel adjoining the milling drum box, to a blow-off location 19, via which the extracted air exits the ground milling machine.In step c), the extracted dust-laden air is fed to the separation device 9, which has a separation chamber designed separately from the milled material conveying channel. The separation chamber thus functionally refers to a spatial compartment that is separate from the conveying channel and is provided for separating dust from the dust-laden air. For this purpose, in step d), the dust-laden air is passed through a separation section 23 in the separation chamber, where the dust-laden air comes into contact with the separation fluid, thereby separating dust from the supplied dust-laden air and absorbing it into the separation fluid. During ongoing operation, in step e), the dust absorbed in the separation fluid is collected within the separation fluid reservoir 24.In step f), downstream of the separation section 23, the air cleaned of dust is discharged from the separation chamber via an extraction air outlet 22 and, finally, in step g), the cleaned air is passed on to the blow-off point 19, via which the extracted air exits the soil milling machine 1.

[0090] The method 56 according to the invention can be developed in a variety of ways. For example, it can be provided that in a step h), the extracted dust-laden air is passed upstream of the separation device through a pre-separator and / or in a step i), the cleaned extracted air is passed downstream of the separation section in the extraction air duct through a device for separating separating liquid droplets from the cleaned extracted air.

[0091] Within the separation device, in step j), the separation liquid can be atomized into droplets and the droplets of separation liquid created during atomization can be collected and / or the separation liquid can be removed from the separation liquid reservoir for atomization. Additionally or alternatively, it can also be provided that in step j), the extracted dust-laden air is directed directly into a liquid volume of the separation liquid via the extraction air supply.

[0092] Step e) may comprise concentrating and / or separating dust particles contained within the separation liquid within the separation device by means of a separation device and / or removing dust-containing separation liquid and / or dust sludge accumulated in the separation device from the separation device by means of a transport device.

[0093] Before and / or after the milling operation of the soil milling machine, it can be provided that a change of the separation liquid takes place by removing a separation module from a base machine of the soil milling machine and by adding another separation module to the base machine, wherein the separation module can each comprise at least a part of the separation chamber, in particular the separation liquid reservoir.

[0094] It is possible that in step m), a starting pressure pulse is triggered to activate the separation device. The starting pressure pulse is preferably selected such that its maximum pressure at the extraction air supply to the separation chamber is greater than the pressure generated at the extraction air supply by an extraction fan during normal operation.

[0095] During operation of the floor milling machine, process parameters can be recorded using a sensor system, such as Fig. 9 already explained, and / or operating variables of the soil milling machine, in particular the separating device 9, are regulated, as also for example for Fig. 9 This is already explained in the Fig. 10 with step n), whereby for concrete design variants, particular reference is made to the information on Fig. 9 reference is made.

Claims

1. Method (56) for reducing dust during milling operation of a self-propelled ground milling machine (1), in particular a road milling machine, recycler or stabilizer, comprising the steps of a) carrying out a milling operation and driving over a ground surface; b) during the ongoing milling process, suction of dust-laden air from a milling drum box (10) and / or a region of a milling material conveying channel (55) adjoining the milling drum box (10), via which milling material milled from the ground surface can be conveyed from the milling drum box (10) to a discharge point (14), by means of a suction device (16) comprising a suction air duct extending from a suction location at which the dust-laden air is suctioned from the milling drum box (10) and / or the region of the milling material conveying channel (55) adjoining the milling drum box (10), to a blow-off location (19) via which the suctioned air can exit the ground milling machine (1),c) feeding the extracted dust-laden air to a separation device (9) with a separation chamber formed separately from the milled material conveying channel (55); d) in the separation chamber, passing the dust-laden air through a separation section (23), in which the dust-laden air comes into contact with the separation liquid, thereby separating dust from the supplied dust-laden air and absorbing the dust in the separation liquid; e) collecting dust absorbed in the separation liquid within a separation liquid reservoir (24); f) downstream of the separation section (23), discharging the dust-cleaned air from the separation chamber via an extraction air outlet (22); and g) passing the cleaned air to a blow-off point, via which the extracted air exits the ground milling machine (1);wherein during the execution of the method (56), at least one of the following process parameters is detected: - a fill level of the separation liquid and / or a dust sludge and / or a degree of contamination of the separation liquid; - a degree of contamination of the separation liquid; - an amount of accumulated dust sludge; - a pressure within the separation device (9).

2. Method (56) according to claim 1, characterized by thatit has at least one or more of the following features: - The extracted dust-containing air is guided upstream to the separation device (9) through a pre-separator (31); - downstream to the separation section (23), the cleaned extracted air is guided in the extraction air duct (18) through a device (29) for separating droplets of separating liquid from the cleaned extracted air; - within the separation device (9), the separating liquid is atomized into droplets and the droplets of separating liquid produced during atomization are collected; - the separating liquid is removed from the separating liquid reservoir for atomization.

3. Method (56) according to one of the preceding claims, characterized by thatit comprises at least one or more of the following features: - The extracted dust-containing air is guided directly into a liquid volume of the separation liquid via the extraction air supply; - dust particles absorbed within the separation liquid are concentrated and / or separated within the separation device (9) with the aid of a separation device (27); - dust-containing separation liquid and / or dust sludge accumulated in the separation device (9) are removed from the separation device (9) with the aid of a transport device (42); - the separation liquid is changed by removing a separation module (39) from a base machine (40) of the soil milling machine (1) and by adding another separation module (39) to the base machine (40), wherein the separation modules (39) each comprise at least part of the separation chamber, in particular the separation liquid reservoir (24).

4. Method (56) according to one of the preceding claims, characterized by that a starting pressure pulse is triggered to start up the separation device (9), the maximum pressure of which at an extraction air supply to the separation chamber is greater than the pressure at the extraction air supply (21) generated by an extraction fan (17) during normal operation.

5. Method (56) according to one of the preceding claims, characterized by thatduring the implementation of the method (56), in particular additionally, at least one of the following process parameters is recorded: - a dust emission of the ground milling machine (1) during milling operation; - a pressure within the separation device (9) downstream of the extraction fan and / or at the extraction air supply and / or at the extraction air outlet and / or at the blow-off location and / or - a rotational speed and / or power consumption of a fan drive; - a travel speed and / or milling depth of the ground milling machine (1); - a closed state of a cleaning opening.

6. Method (56) according to one of the preceding claims, characterized by thatDuring the execution of the method (56), at least one of the following operating variables is controlled as a function of one of the recorded process parameters: - suction power of the suction device (16), in particular of a suction fan; - fan speed of the suction fan (17) and / or suction cross-sectional area of ​​a suction opening; - delivery rate of a pump conveying the separating liquid; - operation of a transport device.

7. Self-propelled soil milling machine (1), in particular road milling machine, recycler or stabilizer, for milling an area of ​​a soil surface to a milling depth, comprising - a machine frame (3) carried by driving devices (5) and having a drive motor (7), - a milling drum rotatably mounted in a milling drum box (10) arranged on the machine frame (3) for milling the area of ​​the soil surface and - a suction device (16) for sucking dust-laden air out of the milling drum box (10) and / or a region of a milling material conveying channel (55) adjoining the milling drum box (10), via which milling material milled from the soil surface can be conveyed from the milling drum box (10) to a discharge point (14), - the suction device (16) comprising a suction air duct extending from a suction location,at which the dust-containing air is extracted from the milling drum box (10) and / or the area of ​​the milling material conveying channel adjoining the milling drum box (10), extends to a blow-off point (19) through which the extracted air can escape from the ground milling machine (1), and an extraction fan (17), , characterized by thatthe extraction air guide (18) has a separation device (9) with a separation chamber formed separately from the milling material conveying channel (55), in which a separation liquid is present for separating dust from the extracted dust-containing air, wherein the separation chamber comprises - an extraction air supply (21) which is designed such that the extracted dust-containing air enters the separation chamber via it, - downstream of the extraction air supply (21) a separation section (23) which is designed such that the dust-containing air comes into contact with the separation liquid and thereby dust is separated from the supplied dust-containing air and absorbed by the separation liquid, - downstream of the separation section (23) an extraction air outlet (22) which is designed such that purified extracted air can exit from the separation device (9) via it, and - a separation liquid reservoir (24) which is designed in such a waythat either the dust-containing air is passed directly through the separating liquid reservoir (24) and / or separating liquid, in which dust has been absorbed from the supplied dust-containing air, is collected in the separating liquid reservoir (24), and , that a sensor device (49) is provided which is designed to detect at least one of the following process parameters: - fill level of the separating liquid; - degree of contamination of the separating liquid; - extent of accumulated dust sludge; - pressure within the separating device (9); - speed of a fan drive.

8. Self-propelled soil milling machine (1) according to claim 7, characterized by thatit has at least one of the following features: - the extraction fan (17) is arranged upstream of the separation device (9); - a pre-separator is arranged in the extraction air duct (18) upstream of the separation section (23) and in particular upstream of the extraction fan (17); - the extraction device (16) has, downstream of the separation section (23) in the extraction air duct (18), a device (29) for separating droplets of separation liquid from the cleaned, extracted air; - the separation device (9) comprises an atomization device (31), wherein the separation device (9) is designed in particular such that the separation liquid supplied to the atomization device (31) is withdrawn from the separation liquid reservoir (24) by means of a recirculation pump (34).

9. Self-propelled soil milling machine (1) according to one of claims 7 or 8, characterized by thatit has at least one of the following features: - the extraction air supply (21) is designed such that the extracted dust-containing air is guided directly into a liquid volume of the separation liquid within the separation chamber; - the extraction air supply (21) has a plurality of outlet openings, via which the extracted dust-containing air is guided directly into the liquid volume of the separation liquid.- a baffle plate (60) is arranged in the separating liquid reservoir (24) and / or at least part of the separating device (9), in particular at least the separating liquid reservoir (24), is mounted in a vibration-damped manner relative to the machine frame (3) of the ground milling machine (1); - within the separating liquid reservoir (24) there is a deflection device (28) which is designed such that it extends the path of the air dispersed in the separating liquid volume within the separating liquid volume from the suction air supply (21) to the outlet from the separating liquid volume; - within the separating device (9) there is a separation device (27) which is designed such that dust particles absorbed within the separating liquid are concentrated and / or separated from the separating liquid.

10. Self-propelled soil milling machine (1) according to one of claims 7 to 9, characterized by that a transport device (42) is provided which is designed such that dust-containing separation liquid and / or dust sludge accumulated in the separation device (9) can be removed from the separation device (9), wherein the transport device is in particular a closable and openable drain or a conveyor device, in particular designed such that the dust sludge is transported to a milling material conveyor device.

11. Self-propelled soil milling machine (1) according to one of claims 7 to 10, characterized by thatthe separation device (9) has at least one of the following features: - it has a rinsing device for cleaning at least part of the separation device (9), in particular for rinsing dust sludge from the interior of the separation device (9) to an outside of the ground milling machine (1); - it has a removal module (39) that can be removed from outside a base machine (40) of the ground milling machine (1), wherein the removal module (39) is designed to receive dust-containing separation liquid and / or accumulated dust sludge during operation of the separation device (9).

12. Self-propelled soil milling machine (1) according to one of claims 7 to 11, characterized by thatat least a part of the separation device (9), in particular the separation liquid reservoir (24), is designed as a removal module (39), wherein the removal module (39) is mounted in particular on a trailer (41) pulled by the base machine (40) and / or directly on or in the base machine (40).

13. Self-propelled soil milling machine (1) according to one of claims 7 to 12, characterized by that the ground milling machine (1) comprises a control device (47), and in that the ground milling machine (1) is designed to carry out the method (56) according to one of claims 1 to 12, wherein the control device (47) is designed in particular such that it controls at least one of the following operating parameters of the ground milling machine (1): - speed of a fan drive of the extraction fan (17); - suction power of the extraction device (16); - delivery rate of a pump (34) conveying the separating liquid; - operation of a transport device (42).

14. Self-propelled soil milling machine (1) according to one of claims 7 to 13, characterized by that the sensor device (49) is further designed to detect at least one of the following process parameters: - dust emission of the ground milling machine (1) during milling operation; - pressure within the separation device (9) downstream of the extraction fan (17) and / or at the extraction air supply (21) and / or at the extraction air outlet (22) and / or at the blow-off location (19).

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