WO2016177603A1

WO2016177603A1 - Grinding roller with a cooling device

Info

Publication number: WO2016177603A1
Application number: PCT/EP2016/059283
Authority: WO
Inventors: Christina FEDER; André DORNBLUT; Carsten Bock
Original assignee: Thyssenkrupp Industrial Solutions Ag; Thyssenkrupp Ag
Priority date: 2015-05-07
Filing date: 2016-04-26
Publication date: 2016-11-10
Also published as: DE102015208484A1; CN107567357A; EP3291914B1; EP3291914A1; PE20180793A1; CL2017002788A1

Abstract

The present invention relates to a grinding roller (11) for a rolling mill, which grinding roller is mounted on a grinding roller shaft (12) so as to be rotatable about its longitudinal axis, wherein the grinding roller shaft (2) has an axial bore (14) in which there is arranged a cooling device (10) which has at least one pipe (16, 20) which is arranged in the bore (14), wherein a first duct (18) for guiding a coolant is formed between the pipe (16, 20) and the inner surface of the bore (14) and a second duct (24) for guiding the coolant is formed within the pipe (16, 20), wherein the at least one pipe (16, 20) is formed from a plastic.

Description

Grinding roller with a cooling device

The invention relates to a grinding roller of a roller mill with a cooling device for cooling the grinding roller.

For crushing materials such as rocks, ores, coal or other materials usually grinding rollers are used. Known grinding rollers comprise two roller bodies, which rotate in opposite directions to each other and shred material introduced between the grinding rollers.

During the grinding process, in particular at the bearing points of the shaft and on the roller surface, process heat occurs, which ensures heating of the grinding system and thus requires cooling. Usually, the shaft of the grinding roller via a cooling water circuit in a

Shaft bore cooled, wherein a coolant is passed through a bore in the grinding roller shaft. Damage caused by deposits and corrosion on the grinding roller shaft and the cooling device is frequently the result of the operation of known cooling devices.

A cooling device of a grinding roller of a roller mill is known for example from DE 10 2012 106 527 AI. The production cost and the production cost of such known cooling devices for grinding rollers are high, with the assembly, especially in

Work environments with small mounting spaces is expensive.

On this basis, it is an object of the present invention to provide a grinding roller with a

Provide cooling device for cooling the grinding roller, which avoids damage due to corrosion and at the same time simple and inexpensive to manufacture and assemble.

This object is achieved by a grinding roller with the features of

independent device claim 1 solved. Advantageous developments emerge from the dependent claims.

A grinding roller for a roller mill, which rotates about its longitudinal axis on a

Grinding roller shaft is mounted, according to a first aspect comprises an axial bore in the grinding roller shaft, in which a cooling device is arranged, which has at least one arranged in the bore tube, wherein between the tube and the inner surface of the bore, a first channel for guiding a coolant and within the tube a second channel to Guide the coolant is formed, wherein the at least one tube is formed of a plastic.

A pipe formed of plastic has no electrical conductivity and offers the advantage that no corrosion can occur by flowing along the pipe coolant along the pipe. Furthermore, a tube made of plastic has a high temperature resistance, which is advantageous in particular when used in a cooling device of a grinding roller of a roller mill, since during operation of the roller mill, as well as during storage and transport of the cooling device temperatures of about -40 ° C to + 80 ° C, especially -20 ° C to + 40 ° C occur.

In contrast to tubes formed, for example, of metal, a plastic tube has a low thermal conductivity, so that, for example, a coolant flowing through the first channel hardly heats coolant, preferably not at all, flowing in the second channel. The plastic tube isolates the first channel thermally from the second channel, with no additional coating or space between the first channel and the second channel necessary. In particular, the plastic pipe has a wall thickness of 10mm to 30mm and is inelastic. A plastic tube is also easy and inexpensive to produce. For example, the tube is made of a high-density polyethylene (PE-HD) or a polyvinylidene fluoride (PVDF), which are also particularly inexpensive. Such plastics also have a resistance to chemicals, so that when cleaning the cooling device, in particular with phosphoric acid, no damage to the pipes occurs.

According to a first embodiment, the cooling device has a first tube and a second tube, which is arranged within the first tube, wherein the interior of the second tube forms the second channel for guiding the coolant. In particular, the tubes are arranged coaxially with each other in the bore. A two-tube cooling device allows reliable thermal isolation of the first channel from the second channel, the first channel between the outer surface of the first tube and the inner surface of the bore of the first channel

Grinding roller shaft is arranged. Also, the second tube is preferably formed of a plastic. According to a further embodiment, the second tube has a smaller diameter than the first tube and is arranged coaxially therewith so that a gap is formed between the tubes. The space between the two tubes of the

Cooling means provides additional thermal isolation of the first channel from the second channel, so that a high temperature difference of the coolant in the first channel to the coolant in the second channel is possible.

The cooling device has according to a further embodiment exactly one tube, wherein the interior of the tube forms the second channel. A cooling device with only one tube allows a reduction of the components of the cooling device and thus a

Cost savings. The assembly of the cooling device in the grinding roller shaft, as well as the maintenance of the cooling device is simplified by a reduced number of components, resulting in a cost and time savings. The reduction of the components of the cooling device to only one tube is made possible, in particular, by the formation of the tube from a plastic, since the use of a plastic tube makes it possible to dispense with additional insulation of the first channel from the second channel.

The second channel forms according to a further embodiment of a return for heated in the first channel coolant. During operation of the cooling device, the coolant flows from a coolant inlet at one end of the bore through the first channel along the inner surface of the bore, wherein the coolant is heated and the grinding roller shaft is cooled. Following the first channel, the coolant flows through the second channel inside the tube back to a coolant outlet. The flow direction of the coolant described has the advantage that the coolant is guided directly after the coolant inlet directly along the surface to be cooled, namely the inner surface of the bore, which allows a particularly efficient cooling.

The tube is arranged according to a further embodiment substantially coaxially with the bore. This allows efficient cooling of the grinding roller shaft, with the coolant being guided along the inner surface of the bore.

According to another embodiment, the outer diameter of the tube over the entire extension of the tube is less than the inner diameter of the bore, so that the first channel between the outer surface of the tube and the inner surface of the bore is formed. The cooling device has, according to a further embodiment, at least one spacer, which spaces the tube to the inner surface of the bore. This allows centering of the at least one tube of the cooling device in the bore, so that a distance between the tube and the inner surface of the bore is ensured and a flow through the first channel is made possible.

The spacer is substantially annular in shape and attached to the outer tube circumference. Ring-shaped spacers allow easy mounting of the cooling device in the bore. In particular, the annular spacer has projections which are formed as skids and slide during assembly of the tube in the bore on the inner surface of the bore, whereby damage to the inner surface of the bore is avoided. An annular spacer also allows easy centering of the tube in the bore.

The at least one tube has according to a further embodiment at least two separate pipe sections, which are connected to each other via a connecting device.

In particular, a plurality of pipe sections are conceivable, which are connected together to form a tube. For example, a pipe 2 to 10, in particular 4 to 6 pipe sections. The pipe sections preferably have the same length, whereby the production of the pipe sections is simplified. A plurality of pipe sections enables easy assembly and disassembly of the cooling device in the grinding roller shaft. In particular, when mounted roll mills, which are used for example in cement works or in opencast mining / underground mining, the mounting space available for mounting or dismounting of the cooling device is often very small, so that a tube which is approximately the length of

Mahlwalzenwelle has to be mounted very difficult and time consuming. A tube comprising several pipe sections simplifies the assembly and disassembly of the cooling device considerably.

The pipe sections are releasably connected to each other according to another embodiment, which allows a quick disassembly of the individual pipe sections. The

Connecting device is in particular a screw or clamp connection. The pipe sections are preferably connected to one another via a sleeve, in particular a double sleeve. A sleeve has a small thickness and thus allows a sufficient distance of the connecting means to the inner surface of the bore of the grinding roller shaft. According to a further embodiment, the first channel and the second channel are in fluid communication via a connecting element such that coolant flowing through the first channel flows into the second channel. The cooling device according to a further embodiment is mounted in the bore such that the cooling device is stationary relative to the grinding roller shaft. During operation of the roller mill, the grinding roller shaft rotates about its longitudinal axis, wherein the cooling device mounted in the bore of the grinding roller shaft rotates with the grinding roller, so that the cooling device and the grinding roller do not move relative to one another.

Description of the drawings

The invention is explained in more detail below with reference to several embodiments with reference to the accompanying figures.

Fig. 1 shows a schematic representation of a section of a grinding roller shaft with a cooling device in a sectional view according to an embodiment. 2 shows a schematic representation of a section of a grinding roller shaft with a cooling device of a sectional view according to a further exemplary embodiment.

Fig. 1 shows a section of a grinding roller shaft 12 on which a grinding roller is mounted in a manner not shown. The grinding roller shaft 12 has an axial bore 14 passing through the grinding roller shaft 12. The grinding roller shaft 12 further includes a cooling device 10 disposed in the bore 14. The cooling device 10 comprises a first inside the bore 14 and coaxially disposed therewith tube 16. Der

Outer diameter of the first tube 16 is less than the inner diameter of the bore 14, so that between the inner surface of the bore 14 and the outer surface of the tube 16, a first channel 18 is formed for guiding a coolant. Coaxially to the first tube, a second tube 20 is arranged. The second tube 20 has a smaller diameter than the first tube 16 and is disposed within the first tube 16, so that between the first tube 16 and the second tube 20, a gap 22 is formed. The interior of the second tube 20 forms a second channel 24 for guiding the coolant. The first pipe 16 and the second tube 20 have the same length and are formed of a plastic.

The first tube 16 and the second tube 20 are each divided into two tube sections 16a, 16b and 20a, 20b, which are formed as separate components. The pipe sections 16a, 16b, 20a and 20b each have the same length, so that the tubes 16 and 20 are divided centrally in the radial direction. The axially juxtaposed pipe sections 16 a, 16 b are connected to each other via a connecting device 46, so that they form the first tube 16. In the same way, the pipe sections 20a and 20b are connected to each other via a

Connecting means 48 connected to the second tube 20, wherein it is in the

Connecting means 46, 48 is for example a sleeve.

In the first channel 18 between the first tube 16 and the inner surface of the bore 14, a plurality of spacers 36 are further arranged, which space the first tube 16 to the inner surface of the bore 14. The spacers 36 are substantially annular in shape and mounted on the outer periphery of the first tube 16, so that they are rotatably connected to the tube 16. By way of example, four are in the embodiment in Fig. 1

Spacer 36 attached. The spacers 36 also have passages for the coolant, so that a flow of the coolant through the first channel 18 is made possible.

The bore 14 through the grinding roller shaft 12 has at its one end a cover 26 which has a substantially circular cross section and through which the bore 14 is sealed against the environment. The cover 26 is followed by a connecting element 28 in the direction of the bore 14. The connecting element 28 enables a fluid connection of the first channel 18 and the second channel 24

Connecting element 28 at least one passage, which allows a flow of coolant from the first channel 18 into the second channel 24. The connecting element 28 allows a flow of the coolant from the first channel 18 into the second channel 24 and at the same time prevents a flow of the coolant from the first channel 18 or the second channel 24 into the intermediate space 22. The connecting element 28 is connected to the first tube 16 and attached to the second tube 20, wherein the connecting element 28 is not applied to the cover 26.

The first tube 16 and the second tube 20 extend from the connecting member 28 to the other end of the bore 14 of the grinding roller shaft 12. The cover 26th

opposite end of the bore 14 has a coolant connection 30, which in Fig. l is shown schematically. The coolant port includes a coolant inlet 32 in fluid communication with the first channel 18 and a coolant outlet 34 in fluid communication with the second channel 24.

During operation of the grinding roller, the grinding roller shaft 12 rotates about its central axis, the

Cover 26 rotates with the grinding roller shaft 12. The cooling device 10 arranged in the bore 14 of the grinding roller shaft 12 is connected to the grinding roller in such a way that it rotates about the longitudinal axis with the grinding roller during operation of the grinding device. The spacer 36 slides only during assembly of the cooling device on the inner surface of the bore 14th

10

To cool the grinding roller, coolant flows through the coolant inlet 32 into the first channel 18 along the inner surface of the bore 14, thereby cooling the grinding roller shaft 12 along the bore 14. The heated coolant flows at the end of the bore into the connecting element 28, through which it is passed into the second channel 24. The second

15 channel 24 forms a return of the heated coolant, wherein the gap 22 between the first channel 18 and the second channel 24 prevents heat transfer of the heated coolant of the second channel 24 to the coolant of the first channel 18. It is also possible to reverse the flow direction of the coolant so that coolant flows from a coolant inlet 34 into the second channel 24 and through the connecting element

20 28 is passed into the first channel 18, in which it flows along the inner surface of the bore 14 and generates a cooling of the grinding roller shaft 12.

Fig. 2 shows another embodiment of a cooling device, wherein the structure of the grinding roller shaft 12 with the bore 14 corresponds to the embodiment of FIG. in the

In contrast to FIG. 1, the cooling device 12 from FIG. 2 has only one tube 38, which is arranged coaxially with the bore 14 within it. The tube 38 has a smaller diameter than the bore 14 and is arranged centrally within the bore 14.

Between the outer circumference of the tube 38 and the inner surface of the bore 14, a first channel 18 is formed, in which the coolant for cooling the inner surface of the bore 14 of the

30 grinding roller shaft 12 flows. Within the tube 38, a second channel 24 is formed for guiding the coolant, which forms a return of the heated coolant. The first channel 18 and the second channel 24 are separated by the tube 38 in the embodiment shown in FIG. At one end of the bore, as described with reference to FIG. 1, a cover 26 is mounted non-rotatably on the grinding roller shaft 12. Adjoining the cover 26 in the direction of the bore 14 is a connecting element 40 which has at least one passage,

For example, at least one through hole, which has a fluid connection

5 between the first channel 18 and the second channel 24 represents. The throughbore is preferably centered and has a smaller diameter than the second channel 24, so that a backflow from the second channel 24 into the first channel 18 is avoided. The tube 38 further comprises two pipe sections 38a and 38b, which are formed approximately identically and are arranged side by side in the bore 14. The pipe sections 10, 38a, and 38b are detachably connected to each other via a connection 44, such as a sleeve. By way of example, the tube 38 in the embodiment of FIG. 2, two pipe sections 38a and 38b, wherein a higher number of pipe sections, for example, 3, 4, 5 or 6 pipe sections would also be conceivable.

The cooling device 10 also has a plurality of spacers 42, which are formed substantially annular. By way of example, in the exemplary embodiment of FIG. 2, four spacers 42 are arranged, which are mounted circumferentially on the tube 38. The

Spacers 42 are mounted on the tube 38 so as to be substantially equidistant from each other, with the spacers 42 being fixed to the tube 38 in a rotationally fixed manner and sliding along the interior of the bore 14 during assembly of the cooler into the grinding roller shaft 12 , At the opposite end of the cover 14 of the bore is a coolant port 30 of FIG. L with a coolant inlet 32 and a

Coolant outlet 34 is arranged. In the operation of the roller mill, coolant flows from the coolant inlet 32 through the first channel 18 along the inner surface of the bore 14 of the mill roll shaft 12 through the passages in the connector 40 into the second channel 24 and exits the cooler 10 through the coolant outlet 34 second channel 24 flowing heated

Coolant is in contrast to the embodiment of FIG. 1 only through the wall

30 of the tube 38 separately. The flow direction of the coolant is reversible, so that the

Coolant first through the second channel 24 and then through the first channel 18 along the inner surface of the bore 14 flows.

The first tube 16 described with reference to FIG. 1, the second tube 20, as well as the tube 38 described with reference to FIG. 2 are in particular made of a plastic. The plastic of the first tube 16 and of the second tube 20 according to FIG. 1, as well as of the tube 38 according to FIG. 2, has in particular a low heat conduction coefficient. Thus, in the embodiment of FIG. 1 made of plastic tubes 16 and 20 for thermal insulation of the tubes 16 and 20 against each other, so that between the first channel 18 and the second channel 24 no heat is transmitted. In the embodiment described in Fig. 2, the formed of a plastic tube 38 provides it for a thermal insulation of the first channel 14 of the second channel 24, wherein a gap between the channels has been omitted.

LIST OF REFERENCE NUMBERS

10 cooling device

11 grinding roller

5 12 grinding roller shaft

14 hole

16 first pipe

16a pipe section

16b pipe section

10 18 first channel for guiding a coolant

20 second tube

20a pipe section

20b pipe section

22 space

15 24 second channel for guiding a coolant

26 cover

28 connecting element

30 coolant connection

32 coolant inlet / outlet

20 34 Coolant outlet / inlet

36 spacers

38 pipe

38a first pipe section

38b second pipe section

25 40 connecting element

42 spacers

44 connection / connection device

46 connection / connection device

48 connection / connection device

Claims

claims

l. Grinding roller (11) for a roller mill, which rotates about its longitudinal axis on a

Grinding roller shaft (12) is mounted,

wherein the grinding roller shaft (12) has an axial bore (14) in which a

Cooling device (10) is arranged, which has at least one in the bore (14) arranged pipe (16, 20, 38)

wherein between the tube (16, 20; 38) and the inner surface of the bore (14) a first channel (18) for guiding a coolant and within the tube (16, 20, 38) a second

Channel (24) is designed to guide the coolant,

characterized in that the at least one tube (16, 20, 38) consists of a

Plastic is formed.

A grinding roll (11) according to claim 1, wherein said cooling means comprises a first tube (16) and a second tube (20), said second tube (20) being disposed within said first tube (16) and wherein the interior of said second tube (16) Pipe (20) forms the second channel (24) for guiding the coolant.

3. grinding roller (11) according to claim 2, wherein the second tube (20) has a smaller

Diameter than the first tube (16) and is arranged coaxially therewith, so that between the first tube (16) and the second tube (20) has a gap (22) is formed.

A grinding roller (11) according to claim 1, wherein the cooling means (10) has exactly one tube (38) and the interior of the tube (38) forms the second channel (24).

A grinding roller (11) according to any one of the preceding claims, wherein the second passage (24) forms a return for coolant heated in the first passage (18).

A grinding roll (11) according to any one of the preceding claims, wherein the tube (16, 20; 38) is disposed substantially coaxially with the bore (14).

7. grinding roller (11) according to one of the preceding claims, wherein the

Outer diameter of the tube (16, 20, 38) over the entire extent of the tube (16, 20; 38) is less than the inner diameter of the bore (14) such that the first channel (18) is formed between the outer surface of the tube (16, 20, 38) and the inner surface of the bore (14).

A grinding roll (11) according to any one of the preceding claims, wherein the cooling means (10) comprises at least one spacer (36; 42) spacing the tube (16, 20; 38) from the inner surface of the bore (14).

The grinding roller (11) of claim 8, wherein the spacer (36; 42) is substantially

is annular and is attached to the outer tube circumference.

10. grinding roller (11) according to any one of the preceding claims, wherein the at least one tube (16, 20, 38) at least two separate pipe sections (16a, 16b, 20a, 20b, 38a, 38b), which together via a connecting device (44 ; 46, 48).

11. Grinding roller (11) according to claim 10, wherein the pipe sections (16a, 16b, 20a, 20b, 38a, 38b) are releasably connected to each other.

A grinding roller (11) according to claim 10 or 11, wherein the connecting means (44; 46,48) is a screw or clamp connection.

Grinding roller (11) according to one of the preceding claims, wherein the first channel (18) and the second channel (24) via a connecting element (28; 40) in such

Fluid connection are that flowing through the first channel (18) flowing coolant into the second channel (24).

A grinding roll (11) according to any one of the preceding claims, wherein the cooling means (10) is mounted in the bore (14) such that the cooling means (10) is stationary relative to the grinding roll shaft (12).