EP3052366A2

EP3052366A2 - Heating body for a sanding device, and sending device for a rail vehicle

Info

Publication number: EP3052366A2
Application number: EP14772354.8A
Authority: EP
Inventors: Georg KRISMANIC; Florian HOESCH; Albert Schneider
Original assignee: Knorr Bremse Systeme fuer Schienenfahrzeuge GmbH
Current assignee: Knorr Bremse Systeme fuer Schienenfahrzeuge GmbH
Priority date: 2013-09-30
Filing date: 2014-09-25
Publication date: 2016-08-10
Also published as: DE102013016168A1; WO2015044243A2; WO2015044243A8; WO2015044243A3

Abstract

The invention relates to a heating body (216) for a sanding device (100). The heating body (216) has a heating element (218) and a heat transferring element (220). The heating element (218) is designed to convert electric energy into heat, and the heat transferring element (220) is designed to transmit heat from the heating element (218) to a housing (200) of the sanding device (100) and to transmit a drying air current.

Description

Radiator for a sanding device and sanding device for a rail vehicle

description

The present invention relates to a radiator for a sanding apparatus and a sanding apparatus for a rail vehicle.

Sand for increasing a coefficient of friction between wheel and rail in a rail vehicle can be transported by a stream of air in a hose or pipe.

EP231 1653 describes a sand discharge device for a rail vehicle.

It is the object of the present invention to provide an improved radiator for a sanding apparatus and an improved sanding apparatus for a rail vehicle.

This object is achieved by a radiator for a sanding device and a sanding device for a rail vehicle according to the independent claims.

An air driven sanding device uses energy contained in compressed air to meter and feed sand. The compressed air is released. When you release the compressed air, the compressed air cools down. Under certain environmental conditions, moisture contained in the compressed air can condense out or freeze due to cooling.

A sand supply in a sand container, a sand container and / or a sanding device may become humid under certain climatic conditions. These circumstances can occur when the temperature of the sand container, the sand stock and / or the sanding device falls below the dew point. The sand supply and / or parts of the sanding device - such as nozzles - can freeze when the temperature falls below freezing and moisture is already condensing. In order to ensure safe dosing and safe transport under different climatic conditions, the sanding device can be heated. In this case, a housing of the sanding device and, alternatively or additionally, an air flowing through the sanding device can be heated. A radiator for a sanding device comprises the following features: a heating element configured to convert electrical energy into heat; and a heat transfer member configured to transfer the heat from the heating element to a housing of the sander and a drying air stream.

A sanding apparatus for a railway vehicle comprises the following features: metering means for pneumatically metering a desired amount of sand using a metered air stream; a conveyor for pneumatically conveying the amount of sand to at least one spreading site using a conveying air stream; a decoupling device for the pneumatic decoupling of the metering device and the conveying device, wherein the decoupling device is designed to provide a compensation air flow for compensating a difference between a Ausgangsluft- ström the metering device and an input air flow of the conveyor; and a radiator according to a variant presented here, which is arranged in a housing of the sanding device. A sanding device may be understood to mean a device for providing sand in the region of at least one contact point between a wheel of the rail vehicle and the rail. The area of the contact point can be referred to as a scattering point. A metered air flow can provide a necessary energy for metering the amount of sand. The metered air stream can be provided as compressed air. The metered air flow can be provided with a high pressure level. The dosing air flow can tear a quantitatively larger amount of air and the amount of sand at a low pressure level through the metering device. A conveying air stream may provide necessary energy to convey the amount of sand to the spreading site. The conveying air flow can be provided as compressed air. The conveying air flow can be provided with a high pressure level. The conveying air flow can tear a quantitatively larger amount of air and the amount of sand at a low pressure level through the conveyor. An outlet air flow of the metering device can be a combined air flow from the metering air flow and an air entrained by the metering device. An inlet air flow of the conveyor may be a stream of air entrained by the conveying air flow through the conveyor. During the transition from the high pressure level to the low pressure level, the compressed air can cool down. The radiator can provide warm air that can compensate for the cooling. The radiator may further dry the sand in the sand container. Furthermore, the sanding device can be heated directly, for example, to prevent icing.

The heat transfer member may have a structure for providing a heat transfer surface to the drying air flow and a contact surface with the housing, wherein the heat transfer surface and the contact surface are in a predetermined area ratio. The structure may be formed as at least one rib and provide a large heat transfer area. The contact surface can be flat. Due to the structure, the drying air can be effectively heated. The rib may be formed as a helix, through which the drying air flow flows.

Due to the helix, the drying air flow can have longer contact with the heat transfer surface. The heat transfer element may comprise a base body made of an elastomer which surrounds the heating element. An elastomer is permanently elastic and adapts to the groove. The elastomer may be provided with at least one filler, wherein the filler is adapted to change a heat conductivity of the elastomer, in particular to increase or decrease. The filler may have thermally conductive properties. The filler may have heat-insulating properties. Due to the filler, the elastomer can be adapted to different requirements.

The elastomer may be equipped on a heat transfer surface to the drying air stream with a filler which is adapted to increase the thermal conductivity of the elastomer. Alternatively or additionally, the elastomer may be provided at a contact surface to the housing with a filler which is adapted to reduce the thermal conductivity of the elastomer. As a result, a heat distribution between the housing and the drying air can be shifted in favor of the drying air.

The elastomer may have on the heat transfer surface to the drying air flow a Hmalformige structure for increasing the heat transfer surface. The structure may be configured to guide the drying air flow and to increase a residence time of the drying air flow at the heat transfer surface. Thus, a heat dissipation uniform over the heating element can be made possible. The housing may be designed in several parts, wherein in a first housing part, a circumferential groove around the metering device is arranged, in which the radiator is arranged. The groove can be closed by a second housing part. In the groove, the radiator is well protected. The groove may have a polygonal shape. The groove may have a hexagonal shape. Due to the polygonality, the course of the groove can be arranged at a distance from other components. For example, the groove may be spaced from fasteners such as screws or channels. The groove may have a depth and the radiator may have a height in the relaxed state, wherein the height is greater than the depth, and the radiator is crimped in the installed state of the second housing part. By pinching a good seal against the housing and / or good heat transfer to the housing can be achieved.

The decoupling device may have a pressure compensation chamber for coupling the compensation air flow. The pressure compensation chamber may be arranged in a connecting line between the metering device and the conveyor. The pressure compensation chamber may be a cavity into which the air entrained by the metering air flow and the sand are introduced. The sand can be due to its kinetic energy transported approximately rectilinearly through the pressure equalization chamber, while the air assumes the prevailing in the pressure equalization chamber ambient pressure. Sand and air from the pressure equalization chamber can be drawn in by the conveyor using the flow of conveying air.

The decoupling device may have a bottom inclined to the conveyor device for preventing sand deposits in the decoupling device. The oblique bottom creates a funnel effect, which in the installed position uses gravity to transport the sand to the conveyor.

The decoupling device may have at least one compensating airflow opening to an environment for the compensating airflow. A Ausgleichsluftstromoffnung may be an orifice of a compensation air flow channel. The equalizing air flow channel can direct the equalizing air flow from or to the decoupling device.

The metering device and, alternatively or additionally, the delivery device may have an ejector with at least one ejector bore for providing the metered air flow and, alternatively or additionally, the conveying air flow. An ejector may be a nozzle to whose axis the ejector bore is arranged obliquely. The nozzle may have little or no cross-sectional taper. In this case, the direction of the slope projected onto the nozzle defines a conveying direction of the ejector.

The metering device and, alternatively or additionally, the delivery device may include an injector with at least one injector nozzle for providing the metered air flow and all ternative or complementary to the conveying air flow. An injector can be a nozzle with a pronounced cross-sectional taper. The cross-sectional taper forms up to the cross-sectional taper a funnel-shaped catching nozzle and then to the cross-sectional taper a diffuser. At the narrowest point of the cross-sectional taper is a diffuser neck. The injector nozzle is aligned with the cross-sectional taper and the dosing air flow or the conveying air flow entrain air and sand in the catching nozzle. The injector has a high efficiency. The injector is less susceptible to contamination. The metering device and, alternatively or additionally, the conveying device may have an air amplifier with at least one annular gap for providing the metering air flow and, alternatively or additionally, the conveying air flow. An air amplifier may be a nozzle with a flow optimized cross-sectional taper. The annular gap is arranged in the conveying direction before the cross-sectional tapering and is designed to provide an approximately laminar flow along the wall of the nozzle. The laminar flow tears air and sand through the nozzle. Due to the laminar flow of the sand is only slightly swirled and exits as a directed beam from the air amplifier. The metering device and, alternatively or additionally, the delivery device may have a Venturi nozzle with at least one take-off tube for supplying the amount of sand. The Venturi nozzle can be aligned horizontally in the installation position. Through a Venturi nozzle, the sand can be deflected laterally using the Dosierluftstroms or the conveying air flow. This can be dispensed with a manifold.

The metering device may have at least one false air flow opening to an environment. The false air flow opening may be arranged adjacent to an inlet opening of the metering device. The false air flow opening may be configured to provide a false air flow for fluidizing sand in the region of the inlet opening when the metering air flow flows through the metering device. A false airflow may be the air entrained by the metered airflow through the metering device. The false air flow opening may be the mouth of a false air flow channel. By the false air flow opening of the false air flow can be sucked in with little resistance. Then the sand container can be sealed. The false air flow opening may be arranged obliquely. The false air opening may be closed by a porous medium. The porous medium may be a sintered material. The false air flow opening can be designed as an oblique bore in the region of the inlet opening. The oblique hole prevents penetration of sand.

The metering device may have a scoop above an inlet opening. The scoop may be designed to prevent penetration of sand into the metering device in the absence of the metered air flow. A scoop can be a cover. The scoop can form a gap or channel through which the entrained air and the entrained sand can be sucked. Through the scoop, the sand can be safely stored in the sand container. The metering device can have a feed hopper, through which the sand container can be completely emptied by the metering device. Through the funnel, the sand is transported by gravity to the metering device.

The metering device may have bores which conduct a drying air flow into the sand container. The holes can be formed obliquely downwards. The slope prevents penetration of sand into the holes.

The metering device may have an opening closed by a porous element. The porous element may be a sintered plate. The drying air can be passed through the porous element in the sand container

The drying air can be heated and / or dried.

The sand supply in the sand container can be dried by the drying air stream.

In the hopper holes for the drying air flow can be designed as inclined holes. Due to the oblique holes no sand can penetrate into the holes. Preferred embodiments of the present invention will be explained in more detail below with reference to the accompanying drawings. Show it:

1 is a block diagram of a sanding apparatus according to an embodiment of the present invention;

FIG. 2 is an illustration of a sanding apparatus according to an embodiment of the present invention; FIG.

3 is an illustration of a radiator according to an embodiment of the present invention;

4 shows an illustration of a metering device for a sanding device according to an exemplary embodiment of the present invention;

5 shows an illustration of a conveying device for a sanding device according to an exemplary embodiment of the present invention;

6 shows an illustration of a decoupling device and a conveying device for a sanding device according to an exemplary embodiment of the present invention; and

7 shows an illustration of a conveying device for a sanding device according to a further exemplary embodiment of the present invention.

In the following description of the preferred embodiments of the present invention, the same or similar reference numerals are used for the elements shown in the various drawings and similar, and a repeated description of these elements will be omitted.

1 shows a block diagram of a sanding apparatus 100 for a rail vehicle 102 according to an embodiment of the present invention. The sanding device 100 has a metering device 104, a conveying device 106 and a decoupling device 108. The sanding device 100 is a component of the rail vehicle 102. The metering device 104 is designed to produce a desired pneumatically metered amount of sand. For this purpose, the metering device 104 uses a metering air flow 1 10. When the metering air flow 1 10 flows through the metering device 104, a false air flow 1 12 is entrained by a resulting negative pressure in the metering device 104. The secondary air flow 1 12 is dependent on the metering air flow 1 10. The larger the metering air flow 1 10, the greater the false air flow 1 12. The false air flow 1 12 flows through a sand tank 1 14 with sand 1 16, where at least partially fluidized by the false air flow 1 12 of the sand 1 16 and the amount of sand is entrained. The amount of sand mixed with the false air flow 1 12 to a first two-phase flow 1 18 of sand and 16 16 air. The first two-phase flow 1 18 comprises with the false air flow 1 12 an input air flow of the metering device 104. The first two-phase flow 1 18 mixes again in the metering device 104 with the metering air flow 1 10 to a second two-phase flow 120. The second two-phase flow 120 includes with the secondary air flow 1 12 and the metering air flow 1 10 an output air flow 122 of the metering device. The output airflow 122 transports the metered amount of sand to the conveyor 106. The conveyor 106 is configured to pneumatically convey the amount of sand to at least one scattering location 126 using a conveying airflow 124. The scattering point 126 is located on a wheel 128 of the rail vehicle 102. The scattering point 126 is connected to the sanding device 100 via a sanding hose. The sand 1 16 serves to increase the friction between the wheel 128 and the rail 130. When the conveying air flow 124 flows through the conveyor 106, a third two-phase flow 132 of sand 16 and air or an incoming air flow 134 of the conveyor 106 by a resultant Vacuum entrained in the conveyor 106. The input air flow 134 is dependent on the conveying air flow 124. The larger the conveying air flow 124, the greater the input air flow 134

Intake air flow 134 and delivery air flow 124 mix in the conveyor 106 to an output airflow of the delivery device 106. The output airflow of the delivery device 106 is a fourth two-phase flow 136 of sand 16 and air. The output airflow transports the amount of sand to the scattering site 126.

The output airflow 122 of the metering device 104 is dependent on the metered air flow 1 10. The input airflow 134 of the conveyor 106 is dependent on the conveying air flow 124. The output airflow 122 and the input airflow 134 may have a difference while the amount of sand is the same. The decoupling device 108 is designed to detect the difference between the output air flow 122 of the metering device and the input air flow 134 of the conveyor to compensate pneumatically. For this purpose, the decoupling device 108 provides a compensation air flow 138 for compensating for the difference. The decoupling device 108 decouples the dosing device 104 from the conveyor 106.

In Fig. 1, a pneumatic sand dosing and conveying system 100 is shown. In order to improve the coefficient of adhesion between wheel 128 and rail 130 in rail vehicles 102, under some circumstances it is necessary to spread sand 16 between wheel 128 and rail 130. For this purpose, sanding systems 100 are installed in front of selected wheels 128 of rail vehicles 102. The Sandstreuanlagen 102 consist of the main components reservoir 1 14, doser 104, conveyor 106 and Sandleitschlauch. According to the respective installation situation on the vehicle 102, the course of the Sandleitschlauches can be very different. Thus, there are also different pneumatic resistors, which experiences the two-phase flow sand-air in Sandleitschlauch and which cause different pressure drops in Sandleitschlauch between the beginning and end. This pressure drop has a retroactive effect on the function of the conveyor 106. The affected functions of the conveyor 106 are achievable sand conveying speed and maximum possible sand throughput. If a pneumatic conveyor 106 is used simultaneously as a pneumatic dosing device 104 or if a pneumatic conveyor 106 and a pneumatic dosing device 106 are mounted one behind the other, then the reaction of the pressure drop in the sanding hose also has an effect on the dosing device 104 and thus on the sand flow rate. The approach presented here minimizes and in the ideal case eliminates this retroactive effect on the sand flow. As little wear as possible due to the abrasive sand is allowed.

Doser 104 and conveyor 106 may be separated such that this repercussion is avoided by using different operating principles for doser 104 and conveyor 106. In this case, for example, mechanical piston dispensers can be combined with pneumatic jet nozzle conveyors 106. Also, mechanical rotary vane feeders may be combined with pneumatic conveyors 106. Due to the use of mechanically moving parts, such as pistons and cell wheels for the Doser, the abrasion between the mechanical moving part and the sand is very high.

A method and a device 100 are presented, in which a pneumatic metering device 104 and a pneumatic conveyor 106 are effectively pneumatically decoupled and thus a reaction to the sand flow rate can be minimized or eliminated. In this case, the two-phase flow 1 18 represents the sand flow rate. The decoupling is achieved in that the two-phase flows 120, 134 are brought to ambient pressure within a pressure equalization chamber through a compensation air flow opening to the ambient air. The compensation air flow opening thus enables a compensation air flow 138, which consists of the difference of the air portion 122 of the two-phase flow 120, which is composed of the sum of metered air flow 1 10 and false air flow 1 12, and the air portion 134 of the two-phase flow 132.

Thus, the two-phase flow 136 can be adjusted by the conveying air 124 or influenced by changing the course of the Sandleitschlauches without affecting the sand flow rate representing two-phase flow 1 18. This results in a purely pneumatic metering and conveying system 100, which has no moving parts within the metering and conveying system 100. Despite the use of the purely pneumatic metering and conveying system 100 results in a decoupling of doser 104 and conveyor 106. Furthermore, there is the possibility of blowing the Sandleitschlauches of residual sand, regardless of the activation of the dosing. In addition, the dosage and promotion of the tightness of the reservoir 1 14 are independent.

FIG. 2 shows an illustration of a sanding apparatus 100 according to an embodiment of the present invention. The sanding device 100 corresponds essentially to the sanding device in FIG. 1. The sanding device 100 is here shown in an installed position, so that the sand from the sand container 1 14 flows by gravity to the metering device 104. The sanding apparatus 100 here has a multi-part housing 200 which encloses the metering device 104, the conveying device 106 and the decoupling device 108. Flanged to the housing 200 is the sand container 1 14. The sand container 1 14 is at one, the sanding device 100th facing end, shaped as a funnel. At a tapered end of the funnel, the metering device 104 is arranged. In the illustrated embodiment, the metering device 104 and the conveyor 106 are designed as ejectors with at least two ejector bores 202 each for providing the metered air flow or the conveying air flow. The ejectors have a structurally defined conveying direction. The ejectors each have an inlet opening and an outlet opening. The conveying direction of the ejector of the metering device 104 is aligned from the sand container 1 14 to the conveyor 106. The conveying direction of the ejector of the conveyor 106 points from the metering device 104 to the Sandleitschlauch.

The ejector of the metering device 104 is formed as in the installed position vertically aligned first tube 204. The first tube 204 is inserted into the housing 200. The first tube 204 protrudes into the sand container 1 14. Thus, the inlet opening of the metering device 104 is arranged higher in the installed position, as a lowest point of the sand container 1 14. At an exit point from the housing 200, the tube 204 has a conical taper. An outer diameter of the tube 204 is less in the region of the sand container 1 14 than in the housing 200. An inner diameter of the tube 204 is constant. The ejector bores 202 are disposed obliquely to a center axis of the tube 204 in a shell of the tube 204. The ejector bores 202 point in the conveying direction. The ejector bores are connected to each other via a metering airflow channel extending annularly around the first pipe 204. The metering air flow channel is arranged here in the jacket. The dosing air flow channel is connected to a dosing air flow connection for the dosing air flow. The metering air flow connection is arranged on an outer surface of the housing 200. In operation, the metering air flow is pressed by the Dosierluftstromanschluss in Dosierluftstromkanal. In the metering air flow channel, the metering air flow distributes uniformly to the ejector bores 202. The metering air flow flows through the ejector bores 202 into the first tube 204 and entrains the secondary air in the conveying direction. The metering device 104 has a scoop 206 above the inlet opening. The scoop 206 is configured to prevent ingress of sand into the metering device 104 in the absence of the metered air flow. Between the scoop 206 and the thinner part of the first tube 204, an annular gap is formed, through which the secondary air flow during operation conveys the sand against gravity into the dosing device 104. The metering device 104 has at least one false air flow opening 208 to the environment. The false air flow opening 208 is arranged adjacent to the inlet opening of the metering device 104. The false air flow opening 208 is designed to provide the secondary air flow for fluidizing sand in the region of the inlet opening when the metering air flow flows through the metering device 104. In the region of the sand container 1 14, the false airflow channel has a kink and runs from there approximately parallel to a container wall of the funnel-shaped end of the Sand container 1 14. As a result, the sand can not penetrate in the installed position against gravity in the false air flow channel. The false air flow opening 208 is arranged at the lowest point of the sand container 1 14. The false air flow opening 208 is arranged at a small distance from the first tube 204. The false air flow channel is directed to the first tube 204. Between the false air flow opening 208 and the gap between the scoop 206 and the first tube 204, a mixing area is arranged, in which the sand is mixed with the false air flow to a first two-phase flow or fluidized when the false air from the false air flow opening 208 in the gap flows. Due to the funnel shape of the

Sand container 1 14, the sand from the container by gravity to slip into the mixing area. The first two-phase flow is transported through the metering device 104 and mixes in the metering device 104 with the metering air flow to a second two-phase flow. Between the metering device 104 and the conveyor 106, a manifold is arranged to deflect the two-phase flow in front of the conveyor 106 by 90 degrees laterally.

The ejector of the conveyor 106 is formed as in the installed position horizontally oriented second tube 210. The second tube 210 is inserted into the housing 200. As in the case of the metering device 104, the ejector bores 202 are arranged obliquely to a center axis of the tube 210 in a jacket of the tube 210. The ejector bores 202 point in the conveying direction. The ejector bores are connected to one another via a conveying airflow channel which extends annularly around the second pipe 210. The conveying air flow channel is arranged here in the jacket. The conveying air flow channel is connected to a conveying air flow connection for the conveying air flow. The conveying air flow connection is arranged on an outer surface of the housing 200. In operation, the conveying air flow is pressed by the conveying air flow connection into the conveying air flow channel. In the conveying air flow channel, the conveying air flow distributes uniformly to the ejector bores 202. The conveying air flow flows through the ejector bores 202 and tears in the second tube 210 a third two-phase flow from the entrained sand of the metering device 104 and air in the conveying direction in the Sandleitschlauch with. In the second tube 210, the conveying air flow mixes with the third two-phase flow to a fourth two-phase flow. The second tube 210 has a larger inner diameter than the first tube 204. Subsequent to the second tube 210, the conveyor 106 has a connection flange for the Sandleitschlauch, which projects beyond the outer surface of the housing 200.

Between the metering device 104 and the conveyor 106, the decoupling device 108 is arranged. The decoupling device 108 has a pressure compensation chamber 212 for coupling the compensation air flow. The pressure compensation chamber 212 is arranged in a connecting line between the metering device 104 and the conveyor 106. The pressure compensation chamber 212 has a, to the conveyor 106 obliquely executed bottom. The sloping bottom is designed as a funnel to the connecting line. The floor is designed to prevent sand deposits in the decoupler 108. Deposited sand slips through the hopper in the direction of the conveyor 106. The pressure compensation chamber 212 has a compensation air flow opening 214 to the environment for the compensation air flow. The equalizing air flow opening 214 is connected to the environment through the housing 200 via a compensating airflow channel. In the pressure equalization chamber 212, ambient pressure prevails. The compensating air flow channel extends in the installed position vertically through the housing 200. The openings of the false air flow channel and the compensating air flow channel are protected by an upstream plate from contamination, for example by water and / or solids. When the output airflow representing an air ratio of the second two-phase flow from the metering device 104 and the input airflow representing the air ratio of the third two-phase flow into the conveyor 106 do not match, the equalizing airflow flows through the equalizing airflow port 214 into the pressure equalizing chamber 212.

Starting from a parting line between two housing parts of the housing 200, one of the housing parts has an annular groove around the metering device. The groove is concentrically aligned with the metering device 104. The groove is arranged in the region of the funnel-shaped end of the sand container 1 14. A heating body 216 for the sanding device 100 is arranged in the groove. The groove is interrupted by a wide ren housing part closed. The radiator 216 has a heating element 218 and a heat transfer element 220. The heating element 218 is a heating wire and configured to convert electrical energy into heat. The heating wire 218 becomes hot when electric current flows through the heating wire 218. The heat transfer element 220 is designed to transfer the heat from the heating element 218 to the housing 200 and to a drying air flow.

A first drying air flow channel connects a drying air flow connection on an outer surface of the housing 200 with a first side of the groove facing away from the sand container 1 14. From one, the sand container 1 14 facing the second side of the groove leads at least a second drying air flow channel approximately parallel to the container wall of the funnel-shaped end of the sand container 1 14 to at least one Trocknungsluftstromoffnung. As a result, the sand can not penetrate into the second drying air flow channel in the installed position against gravity. The drying air flow opening is arranged at the lowest point of the sand container 1 14 in the mixing area. The Trocknungsluftstromoffnung is arranged at a small distance from the first tube 204. The second drying air flow channel is directed to the first tube 204.

When the drying airflow is provided over the drying airflow port, it flows through the first drying airflow channel to the heater 216.

When the heating element 218 is in operation, the drying air flow to the heater 216 absorbs heat energy. From the heating body 216, the drying air flow flows through the second drying air flow channel to the drying air flow opening into the mixing area.

If the metering device 104 is in operation and sucks fluidized sand out of the mixing area, then the drying air flow at least partially replaces the false air flow, which decreases accordingly to obtain balanced pressure ratios. The warm drying air stream now heats and / or dries the metering device 104, the decoupling device 108 and consequently also the conveyor 106.

When the metering device 104 is not in operation, the drying air flow flows partly from the mixing area into the sand container 14, where it heats and / or dries the sand. As a result, the sand remains free-flowing and a safe operation of the sanding Device 100 is increased. Another part flows through the secondary air flow channel into the environment, wherein the secondary air flow channel is heated and / or dried.

A part may also flow through the first pipe 204 and further through the equalizing air flow opening 214 and through the second pipe 210 and the sanding hose, which are heated and / or dried by the drying air.

In one embodiment, the heat transfer element 220 has an elastomeric body surrounding the heater wire 218. When not installed, the radiator 216 is narrower than the groove. In this case, the radiator 216 in the relaxed state to a greater height than the groove is deep. Due to the smaller width, as the groove of the radiator 216 can be easily inserted into the groove. When the housing parts are joined together, the elastomer is squeezed, whereby the height of the heater 216 adapts to the depth of the groove. In this case, the width of the radiator 216 increases, whereby the heat transfer element 220 gets in direct contact with the housing 200. Due to the direct contact, a good heat transfer from the heat transfer element 220 to the housing 200 is made possible. When the heater 216 is in operation without providing the drying air flow, the heat energy is primarily transferred to the housing 200, which heats up.

In one embodiment, the heat transfer element 220 has a structure for providing a heat transfer surface to the drying air stream and a contact surface to the housing 200. The heat transfer surface and the contact surface are in a predetermined area ratio. The heat transfer surface to

Drying air flow is formed by a helical, along a first side of the radiator 216 extending rib. The rib is formed of the elastomer and abuts against a first side surface of the groove and thus seals adjacent turns of the resulting drying air flow channel from each other. The drying air flow is spirally guided by the rib along the radiator 216, resulting in a long distance for receiving the heat energy. A second side of the radiator 216 has a corrugated surface structure. The surface structure abuts against a second side surface of the groove. Due to the corrugated surface structure, the contact surface with the housing 200 is reduced with respect to a smooth surface. The heat transfer surface is much larger than the contact surface to the different heat transfer coefficients from the radiator 216 to the drying air flow and the radiator 216 to the housing 200 to be considered.

In the illustrated embodiment, the rib points in the direction of the metering device 104. The corrugated surface faces away from the metering device 104.

In an embodiment not shown, the corrugated surface points in the direction of the metering device 104. The rib points away from the metering device 104. In one embodiment, the elastomer is equipped with two fillers. The first filler is designed to increase a thermal conductivity of the elastomer. The second filler is designed to reduce the thermal conductivity of the elastomer. At the heat transfer surface to the drying air flow, the elastomer is equipped with the first filler, which is designed to increase the thermal conductivity of the elastomer. At the contact surface to the housing 200, the elastomer is provided with the second filler, which is designed to reduce the thermal conductivity of the elastomer.

In one embodiment, the doser 104 consists of the main elements housing 200, ejector tube 204, scoop 206, false air feeds 208, of which only one is simplified, and an air connection and an integrated heating element 216 within a heating chamber, the associated oblique bores, of which simplified only one is shown, and the connection for the drying air flow. In one embodiment, the conveyor 106 consists of the main elements housing 200, pressure equalization chamber 212, equalizing airflow openings 214, of which only one is simplified, manifold, ejector tube 210, hose nozzle and an air connection. In the illustrated embodiment, the housing 200 of the doser 106 is connected to the reservoir 1 14 so that together with the hopper of the reservoir 1 14 can be completely emptied through the device 100 and a uniform sand flow is achieved. In the illustrated embodiment, the doser 104 is connected to the conveyor 106 via an interface between the lower end of the ejector tube 204 and the pressure compensation chamber 212. In one embodiment, the pressure compensation chamber 212 is formed below as a feed hopper so that the sand can not remain in the pressure compensation chamber 212.

In one embodiment, the false airflow opening 208 and the equalizing airflow opening 214 are both protected from external contamination and from water ingress by their downwardly directed air channels and by a fender held by a spacer.

The Sandleitschlauch is connected via the hose nozzle with the device 100.

In operation, the stock 1 14 in-stock sand is prevented by the shape of the scoop 206 on autonomous emptying. In addition, the oblique holes for the drying air flow and the secondary air flow prevent the sand from entering the air ducts and the heating chamber.

By applying a metered air flow at the metering air flow connection, a negative pressure is produced by the ejector bores 202 in the upper part of the ejector tube 204 and, as a consequence, an air flow through the ejector tube 204. The negative pressure and the air flow suck the sand and lift it over the potential barrier formed by the scoop 206 and the ejector tube 204. In this case, a false air flow is sucked in through the bore. Thus, the sand is dosed in the first two-phase flow as a function of the strength of the Dosierluftstroms and regardless of the tightness of the reservoir 1 14 and introduced into the pressure compensation chamber 212. In the pressure compensation chamber 212, the sandblast easily expands and the sand flows due to its inertia further into the manifold. Since the sand is slowed down only slightly, its kinetic energy can be used for its further promotion within the third two-phase flow. In this case, a compensation air flow is formed so that the pressure compensation chamber 212 has the ambient pressure, and thus avoids a retroactive effect on the amount of sand in the two-phase flows. Sand, which due to the stochastic behavior does not hit the elbow, gets through the feeding funnel also directed into the manifold. Very slight amounts of sand can escape directly into the bore of the equalizing air flow channel and continue unused without the risk of clogging the system. Due to the simultaneous application of a conveying air flow at the delivery air flow connection with the metering air flow, a negative pressure and, as a consequence, an air flow through the ejector tube 210 are produced by the ejector bores 202 in the right-hand part of the ejector tube 210. The thereby sucked false air is provided by a part of the compensation air flow, which flows through the bore 214. The compensation air flow can flow into or out of the pressure compensation chamber 212 as a function of the operating point. The operating point depends on the metering air flow, the conveying air flow, the resistance of the sanding hose and / or the cross-section of the sand. The equalizing air flow is a superposition of the air portion of the second two-phase flow with the additionally required or excessively present secondary air flow for the conveyor 106. The airflow present in the ejector tube 210 further conveys the sand through the sand hose, which is connected to the ejector tube 210 via the nozzle Wheel and rail.

After switching off the Dosierluftstroms the remaining sand in the sand still existing sand is transported through the still active conveying air flow from the Sandleitschlauch without sand from the reservoir 1 14 is metered. The conveying air flow is switched off only after complete emptying of the Sandleitschlauches.

A device 100 for dosing and conveying sand 16 for sanding systems in rail vehicles is characterized in that the pneumatic dosing device 104 and the pneumatic conveyor 106 are decoupled by a pressure compensation chamber 212 with a connected equalizing air flow opening 214.

In the lower region of the hopper inclined bores in the housing 200 for the secondary air flow of the doser 104 are present.

The doser 104 is realized by an ejector tube 204 with ejector bores 202.

The conveyor 106 is realized by an ejector tube 210 with ejector bores 202. In one embodiment, a complete emptying of the sand container 1 14 by a correspondingly shaped hopper, which is part of the device 100 realized. In the hopper inclined bores in the housing 200 for the drying air and a heater 216 for heating the drying air flow and the housing 200 are present.

The radiator 216 has a helical structure, which leads the drying air from the drying air connection to the oblique holes within the heating chamber and thus emits the heat evenly to the drying air.

The heat transfer coefficients heating elements 216 on drying air and heating elements 216 on housing 200 are so different that the heat is optimally distributed to drying air and housing 200.

In one embodiment, the different heat transfer coefficients are realized by different thermally conductive materials. In one embodiment, the different heat transfer coefficients are realized by different thermal surface contacts.

The slanted bores in the metered air blower housing 200 are arranged to fluidize the sand in this area.

3 shows an illustration of a radiator 216 according to an embodiment of the present invention. The radiator 216 substantially corresponds to the radiator in FIG. 2. The radiator 216 is annularly closed as in FIG. 2. The radiator 216 has a, deviating from the circular outer contour. The radiator 216 has a polygonal outer contour.

In the illustrated embodiment, the radiator 216 is designed as a hexagonal ring 300. The hexagon has rounded edges. On an inner side of the ring 300, the helical rib 302 is arranged with three complete turns, so that in the space between the turns of the spiral drying drying air flow channel is formed when the radiator 216 is arranged in a correspondingly shaped groove in the housing of the sanding device. The rib 302 has a trapezoidal cross section. The ring 300 has an end surface 304 and a bottom surface 306 which abut the housing when the heater 216 is inserted into the groove and the housing parts are connected to each other.

In the region of the straight sections of the radiator 216 and / or in the region of the corners of the radiator 216 fasteners, lines and / or connecting elements can be arranged in the housing without the To interrupt radiator.

4 shows an illustration of a metering device 104 for a sanding device according to an exemplary embodiment of the present invention. The metering device 104 is arranged in the sanding device, as shown in FIG. In contrast to FIG. 2, the metering device 104 is designed as an injector with an injector nozzle 400 for providing the metered air flow. The injector is designed analogously to a jet pump. The injector nozzle 400 is aligned coaxially with a capture nozzle 402 followed by a diffuser 404. The catching nozzle narrows in a funnel shape up to a diffusor neck, where the catching nozzle has its smallest diameter. From there, the diameter gets bigger again. When the metering air stream flows out of the injector nozzle 400 as a jet, an impulse is transferred to a suction medium in the capture nozzle 402. The suction medium is the first two-phase flow of false air and sand during operation of the metering device 104. The jet mixes in the capture nozzle 402 with the suction medium to the second two-phase flow. The suction medium is entrained in the catching nozzle 402 and thereby accelerated. The jet widens from the injector nozzle 400 and reaches approximately the diameter of the diffuser neck in the diffuser neck. In the diffuser neck, the second two-phase flow reaches its highest speed and the lowest pressure. From here the suction medium and the jet have the same pressure. In the diffuser 404, the second two-phase flow expands to the final diameter of the diffuser 404. In this case, the second two-phase flow is decelerated and compressed again to the pressure prevailing at the final diameter. Since ambient pressure prevails in the decoupling device 108, a distinct negative pressure prevails in the diffuser neck, which attracts the first two-phase flow through access bores 406 out of the mixing region. The injector nozzle 400 is here in the scoop 206 arranged. The metering air flow channel is arranged in a wall of the scoop 206. The access holes 406 are arranged obliquely in the wall. In the installed position of the sanding device, they point diagonally downwards in order to prevent ingress of sand into the metering device 104 outside of the operation. The injector nozzle 400 and the capture nozzle 404 with the diffuser 404 are inserted into the housing 200 as in FIG. 2.

The doser 104 shown in FIG. 4 substantially corresponds to the exemplary embodiment illustrated in FIG. 2. In contrast, the doser 104 is designed with a jet nozzle. The metering device 104 differs in the elements injector nozzle 400 with diffuser 404, scoop 206 with oblique holes, of which only one is simplified, and the supply of the metered air flow from the illustration in FIG. 2. The housing 200 is corresponding to the air guide with respect to FIG. 2 adapted. All other positions are identical to the positions of the embodiment in Fig. 2. The doser 104 is realized by an injector nozzle 400 with diffuser 404.

Functionally, there is a difference compared to the embodiment in Fig. 2. By applying the Dosierluftstroms to the feed through the injector 400 above the diffuser 404, a negative pressure and consequently an air flow through the diffuser 404 is generated. The negative pressure and the air flow suck the sand and lift it over the potential barrier formed by the oblique bores.

5 shows an illustration of a conveyor 106 for a sanding apparatus according to an embodiment of the present invention. The conveyor 106 is as shown in Fig. 2, arranged in the sander. In contrast to FIG. 2, the conveyor 106 is designed as an injector with an injector nozzle 400 for providing the conveying air flow. The function of the injector is as described in FIG. 4. The suction medium is here the third two-phase flow described in FIG. By mixing with the conveying air flow, the fourth two-phase flow is created in the injector. The injector nozzle 400 is designed here as a tube protruding horizontally into the manifold. The conveying air flow channel extends in the extension of the injector 400 straight to the side surface of the housing 200th

The conveyor 106 shown in Fig. 5 corresponds substantially to the embodiment shown in Fig. 2. In contrast, the conveyor 106 is designed with a jet nozzle. The conveyor 106 differs in the elements housing 200, Manifold and injector nozzle 400 with diffuser as shown in FIG. 2. The conveyor 106 is realized by an injector nozzle 400 with a diffuser.

Functionally results in a difference compared to the embodiment in Fig. 2. By the simultaneous with the dosing air flow applying the flow of air to the feed through the injector 400, a negative pressure and consequently an air flow through the diffuser is generated in the right part of the diffuser.

6 shows an illustration of a decoupling device 108 and a conveying device 106 for a sanding device according to an exemplary embodiment of the present invention. The conveyor 106 and the decoupling device 108 are arranged in the sander, as shown in FIG. The decoupling device 108 corresponds to the decoupling device in Fig. 2. In contrast to Fig. 2, the conveyor 106 is designed as an air amplifier with an annular gap 600 for providing the conveying air flow. The conveying air flow exits from the annular gap 600 at almost the speed of sound. The conveying air flow extends from the annular gap due to a geometry of the nozzle 602 along a wall of the nozzle 602 and thereby expands increasingly. As in the injector in Fig. 4, the suction medium, here the third two-phase flow, entrained and accelerated, whereby the negative pressure is created, which sucks the third two-phase flow. The conveying air flow mixes with the third two-phase flow to the fourth two-phase flow.

In one embodiment, the metering device comprises an air amplifier, as shown in Fig. 6, on.

The conveyor 106 shown in Fig. 6 has an air amplifier. The conveyor 106 differs in the elements housing 200 and the air amplifier nozzle 602. The conveyor 106 is realized by an air amplifier. Functionally arises as a difference compared to the embodiments shown in Figures 2 and 4, that created by the simultaneous with the Dosierluftstrom applying a flow of air to the supply a negative pressure to the right of the air amplifier nozzle, which generates an air flow in a row, which sucks the sand and on transported through the nozzle 602. FIG. 7 shows an illustration of a conveying device 106 for a sanding device according to a further exemplary embodiment of the present invention. The conveyor 106 has a Venturi nozzle with at least one take-off tube 700 for supplying the amount of sand. The Venturi nozzle consists of a nozzle 702 and a downstream diffuser 704. The nozzle 702 accelerates the conveying air flow. The pressure in the conveying air flow drops. At the transition from the nozzle 702 to the diffuser 704, the take-off tube 700 is arranged. Due to the negative pressure, the suction medium is sucked in and torn into the diffuser 704. The diffuser 704 opens into the nozzle for the Sandleitschlauch. The take-off tube 700 is connected directly to the decoupling device 108. An end of the take-off tube 700 facing the decoupling device 108 is widened in a funnel shape in addition to the chamfer at the bottom of the pressure compensation chamber 212 in order to concentrate the second two-phase stream emerging from the dosing device 104 into the constriction of the venturi nozzle. The conveyor 106 shown in Fig. 7 has a venturi tube. The conveyor 106 differs in the elements housing 200 and the Venturi tube, consisting inter alia of the feed 700 and the diffuser 704. The conveyor 106 is realized by a Venturi tube 602. As a functional difference with respect to the embodiments shown in Figures 2, 4 and 6 shows that by the simultaneous with the metering air flow applying a flow of air to the feed a negative pressure in the lower part of the hopper arises and in succession an air flow is generated which the sand sucks and further transported through the diffuser 704.

In the dosing and conveying of sand for sanding systems in rail vehicles presented here, a purely pneumatic metering and a purely pneumatic conveying by a compensation air flow is decoupled from each other. The described embodiments are chosen only by way of example and can be combined with each other. LIST OF REFERENCE NUMBERS

100 sanding device

102 rail vehicle

104 Dosing device, dosing device

106 conveyor, conveyor

108 decoupling device

1 10 Dosing air flow

1 12 secondary airflow

1 14 sand container, storage container

1 16 sand

1 18 first two-phase flow air-sand from reservoir to doser

120 second two-phase flow air-sand from meter to the equalization port

122 output airflow

124 conveying air flow

126 scattering place

128 wheel

130 rail

132 third two-phase flow air-sand from equalization opening to the conveyor

134 incoming air flow

136 fourth two-phase flow air-sand from conveyor through Sandleitschlauch between wheel and rail

138 compensating airflow

200 housings

202 ejector holes

204 first pipe, ejector pipe of the dosing unit

206 scoop of the dosing unit

208 false air flow opening

210 second tube, ejector tube of the conveyor

212 pressure compensation chamber

214 equalizing air flow opening

216 radiators

218 heating element

220 heat transfer element 300 ring

302 rib

304 face

306 floor space

400 injector nozzle of the dosing unit or the conveyor

402 catching nozzle

404 Diffuser of the dosing unit

406 access hole, oblique hole for sucking in the sand

600 annular gap

602 nozzle 700 pick-up pipe

702 nozzle

704 diffuser

800 Procedure for Providing Sand

802 step of dosing

804 step of promoting

806 Decoupling step

Claims

Patent claims

Heater (216) for a sanding device (100), the heater (216) having the following features: a heating element (218) designed to convert electrical energy into heat; and a heat transfer element (220) configured to transfer heat from the heating element (218) to a housing (200) of the sanding device (100) and a drying air stream.

Radiator (216) according to claim 1, in which the heat transfer element (220) has a structure (302) for providing a heat transfer surface to the drying air flow and a contact surface to the housing (200), the heat transfer surface and the contact surface being in a predetermined area ratio.

Radiator (216) according to one of the preceding claims, in which the heat transfer element (220) has a base body made of an elastomer which encloses the heating element (218).

Radiator (216) according to claim 3, in which the elastomer is equipped with at least one filler, the filler being designed to change, in particular to increase or decrease, a thermal conductivity of the elastomer.

Radiator (216) according to one of claims 3 to 4, in which the elastomer is equipped on a heat transfer surface to the drying air flow with a filler which is designed to increase the thermal conductivity of the elastomer and / or the elastomer on a contact surface with the housing ( 200) is equipped with a filler that is designed to reduce the thermal conductivity of the elastomer.

6. Radiator (216) according to one of claims 3 to 5, in which the elastomer has a helical structure on the heat transfer surface to the drying air flow (302) for increasing the heat transfer surface, the structure being designed to guide the drying air flow and to increase a residence time of the drying air flow on the heat transfer surface and thus enable uniform heat release via the heating element.

Sanding device (100) for a rail vehicle (102), the sanding device (100) having the following features: a metering device (104) for pneumatically metering a desired amount of sand using a metering air stream (1 10); a conveyor device (106) for pneumatically conveying the amount of sand to at least one spreading point (126) using a conveying air flow (124); and a decoupling device (108) for pneumatically decoupling the metering device (104) and the conveying device (106), the decoupling device (108) being designed to generate a compensating air flow (138) for compensating for a difference between an output air flow (122) of the metering device (104 ) and an input air flow (134) of the conveyor (106); and a heater (216) according to one of claims 1 to 6, which is arranged in a housing (200) of the sanding device (100).

Sanding device (100) according to claim 7, in which the housing (200) is designed in several parts, a groove running around the metering device (104) being arranged in a first housing part, in which the heating element (216) is arranged, the groove being provided by a second housing part is closed.

Sanding device (100) according to claim 8, in which the groove has a polygonal shape.

0. Sanding device (100) according to one of claims 7 to 9, in which the groove has a depth and the radiator (216) has a height in the relaxed state, the height being greater than the depth, and the radiator (216) in is squeezed by the second housing part when installed.

1 1 . Sanding device (100) according to one of claims 7 to 10, in which the decoupling device (108) has a pressure compensation chamber (212) for coupling the compensation air flow (138), the pressure compensation chamber (212) being in a connecting line between the metering device (104). and the conveyor device (106) is arranged.

12. Sanding device (100) according to one of claims 7 to 1 1, in which the decoupling device (108) has a bottom which is inclined towards the conveyor device (106) to prevent sand deposits in the decoupling device (108).

13. Sanding device (100) according to one of claims 7 to 12, in which the decoupling device (108) for the compensating air flow (138) has at least one compensating air flow opening (214) to an environment.

14. Sanding device (100) according to one of claims 7 to 13, in which the metering device (104) and / or the conveying device (106) has an ejector with at least one ejector bore (202) for providing the metering air flow (1 10) and / or the Conveying air flow (124).

15. Sanding device (100) according to one of claims 7 to 14, in which the metering device (104) and / or the conveying device (106) has an injector with at least one injector nozzle (400) for providing the metering air flow (1 10) and / or the Conveying air flow (124).

16. Sanding device (100) according to one of claims 7 to 15, in which the metering device (104) and / or the conveying device (106) has an air amplifier with at least one annular gap (600) for providing the metering air flow (1 10) and / or the Conveying air flow (124).

17. Sanding device (100) according to one of claims 7 to 16, in which the metering device (104) and / or the conveying device (106) has a Venturi nozzle (702) with at least one removal tube (700) for supplying the amount of sand.

18. Sanding device (100) according to one of claims 7 to 17, in which the metering device (104) has at least one false air flow opening (208) to an environment, the false air flow opening (208) being arranged adjacent to an inlet opening of the metering device (104) and is designed to provide a false air stream (1 12) for fluidizing sand (1 16) in the area of the inlet opening when the metering air stream (1 10) flows through the metering device (104).

19. Sanding device (100) according to claim 18, in which the false air flow opening (208) is designed as an oblique bore in the area of the inlet opening.

20. Sanding device (100) according to one of claims 7 to 19, in which the metering device (104) has a hood (206) above an inlet opening, the hood (206) being designed to act in the absence of the metering air flow (1 10). To prevent sand (1 16) from entering the metering device (104).

21. Sanding device (100) according to one of the preceding claims, in which the metering device (104) has a feed hopper, the sand container (1 14) being completely empty by the metering device (104).

22. Sanding device (100) according to one of the preceding claims, in which holes for the drying air flow are designed as inclined holes in the feed hopper.