EP1373579B1 - Cooling plate - Google Patents

Abstract

A cooling plate for refractory-lined shaft furnaces includes a first cooling plate element facing the inside of the furnace and a second, rear cooling plate element, where in the cooling plate elements are welded together. A cooling channel is formed between the first and second elements of the cooling plate. Pipe elements are connected to the coolant inlet and coolant outlet. The first cooling plate element is a bloom with a plane front side facing the inside of the furnace, and the cross-sectional area of the cooling channel is larger in the end regions thereof than in the center region, as viewed along the longitudinal extent of the cross-section.

Description

The invention relates to a cooling plate for ver-provided with a refractory lining Shaft furnaces, in particular for blast furnaces, with one to the furnace interior pointing first rolled cold plate part and a second rolled backward cooling plate part, which are welded together, and with a between the first and the second cooling plate part resulting cooling channel and with pipe sections for coolant inlet or coolant outlet. In this case, both the first and the second cooling plate part are made Copper or a low alloy copper alloy. In addition, the invention relates a cooling system.

A generic cooling plate is disclosed in German Offenlegungsschrift DE-A-100 00 987. This discloses a cooling plate for having a refractory Lined shaft furnaces with acted upon by a coolant Cooling channels, at least those facing the furnace interior Front side of a groove equipped with refractory material, preferably of copper or a low alloy copper alloy manufactured billet consists, with two trough-shaped rolling profiles with their Troughs are each welded to the outside and welded together in the back rolled profile or additional profile holes for receiving the Inserted ends of pipe fittings and they are welded and wherein the free ends of the rolled sections are closed by caps.

The bending of the first cooling plate part or shield and the introduction of Grooves in the curved shield is technically complex. In addition, proves itself resulting from the trough shape of the two cooling plate parts in approximately "lenticular" cross-section of the cooling channel as flow-technically unfavorable. While those from the side fins of the shield to the cooling water channel flowing heat is greatest, is just in the corners the "lens" the flow velocity of the cooling water least. The low flow velocity leads to a low heat transfer coefficient α from the inside of the cooling channel to the cooling water. In addition, the amount of water flowing past it heats up inappropriately on.

Document DE-U-20001397 discloses a Cooling plate for with a refractory lining provided shaft furnace, consisting of copper with arranged on the Rüchseite the cooling plates Coolant channels, in part through the Cooling plate itself and the other part through welded sheets are limited.

Document US-A-6 132 673 discloses a cooling plate for shaft furnaces consisting of a copper Walzbloch with a flat front to the oven interior.

The invention is therefore based on the object, a generic cooling plate with improved production, flow and cooling properties to accomplish.

This object is achieved by the cooling plate with the features of claim 1 and solved by the system having the features of claim 12. advantageous Further developments are described in the subclaims.

After the Kemgedanken of the invention, the first cooling plate part or the Shield of the cooling plate or the Stavelets no longer curved, but is as a billet with a flat front to the furnace interior, i. With a flat hot side, formed, and the cross sectional area of the between is the cooling channel resulting from the first and the second cooling plate part in the - seen in relation to the longitudinal extent of the cross-sectional area - End areas is greater than in the middle area. End areas of the cooling channel cross section are the areas near the connecting lines or welds the two cooling plate parts. The end areas can be any shape assuming they have a larger cross-sectional area than the central area. This cross-sectional shape according to the invention causes the largest Part of the cooling water no longer in the middle area, but in the heat-loaded End portions of the cooling channel flows, with higher flow rates and thus more favorable heat transfer coefficient values be achieved. The cross section in the middle region is in the ratio so be interpreted that the there - lower amounts of heat - well dissipated can be.

Overall, in this way a cooling plate with improved flow characteristics the cooling water and thus created cooling properties. It will an equalization of the temperature on the hot side, i. the the Furnace inside facing side, achieved. In addition, there is an essential Production engineering advantage of the fact that now the first cooling plate part plan is formed and no longer needs to be bent. In addition, the introduction of grooves in a flat cooling plate much easier than in a curved, for example by milling or by profile rolling.

According to a particularly preferred embodiment, the end regions of Cooling channel cross-section formed half-sided or bulged on both sides. Under Taking into account the center region results in a cooling channel cross-section, the in approximately with the shape of a bone or cut in its longitudinal axis Half-bone is comparable. This shape is a special good ratio of flow rate of the cooling water to accumulating Achieved thermal loads.

To obtain a cooling channel with such a bone shape are different structural combinations proposed. For a roughly half-bony Cross section are either a first cooling plate part with in his used water-side back recesses introduced or a double trough-shaped, with bulges pointing towards the furnace wall, shaped second cooling plate part. Such a first cooling plate part is provided with a in approximately plan second cooling plate part combined; a trough-shaped second cooling plate part is provided with a first cooling plate part with a flat water side Back combined. To obtain a bone-shaped cross-section is a first cooling plate part with recesses with a corresponding second cooling plate part with recesses or with a double trough-shaped second cooling plate part combined.

The recesses, which are preferably parallel to the longitudinal axis of the cooling plate, are introduced by roll forming or by milling. The trough-shaped second cooling plate part, which is formed thinner than the first cooling plate part is made by roll forming or bending.

Both the first and the second cooling plate part are made of copper or a copper alloy.

The trough-shaped second cooling plate part according to a preferred embodiment across its width on a different material thickness. It is on formed thicker edges than in its center region. This has the advantage that in the region of the increased heat flow, i. in the edge area, more copper material and thus more material is available for heat conduction. Due to the reinforced edge areas, the weld seam can also be used for connection the two parts are made solid with each other. This carries for the mechanical stability of the cooling plate and thus also for further improvement the cooling characteristics.

A second cooling plate part can be welded to the edges of the first cooling plate part be, according to a preferred embodiment, it is in the sense a supplementary profile with its to the back of the first cooling plate part bent longitudinal edges welded to the back of the first cooling plate part. In order to wavy the edges of the first cooling plate part due to prevent an uneven temperature distribution, it is suggested in the edge regions of the first cooling plate member perpendicular to the longitudinal axis to insert slots in the cooling plate at regular intervals.

In a preferred embodiment, the free ends of the two are together connected cooling plate parts with caps closed, and the pipe sections for the coolant inlet and outlet protrude through holes in the rear second cooling plate part. To water-side pressure losses in the range of the coolant inlet or outlet is the first cooling plate part, which is provided with cooling channel recesses, hollowed out at the height of the pipe sections, for example, by milling away the copper. A transition of the so enlarged entrance or exit area to the cooling channel wells is achieved in that the depth of the cavity ramped to the cooling channel recesses decreases. The reason for the lower pressure losses is a now present softer transition from the round tube section to the invention proposed cooling channel cross-section with larger end portions and small center area.

In addition to a bridge-bracket connection is to suspend the cooling plate the furnace wall of the shaft furnace proposed that the cooling plate at least having two suspension points, wherein a first suspension point as a solid connection in the upper part of the cooling plate, preferably above the Pipe section for coolant inlet or - outlet, is formed and a second suspension point as a loose connection in the lower part of the cooling plate, preferably just above the pipe section for coolant inlet or exit, is trained. This advantageous suspension with Lospunkte, which are preferably designed as a suspension, it is achieved that the lower part of the cooling plate can thermally expand.

Fig. 1

einen Querschnitt einer Kühlplatte nach einer ersten Ausführungsform;

Fig. 2

einen Querschnitt einer Kühlplatte nach einer zweiten Ausführungsform;

Fig. 3

einen bevorzugt ausgebildeten zweiten Kühlplattenteil nach Fig. 2;

Fig. 4

einen Längsschnitt einer an einer Schachtofenwandung montierten Kühlplatte;

Fig. 5

einen Teilausschnitt eines Längsschnitts eines bevorzugt ausgebildeten ersten Kühlplattenteils nach Fig. 1;

Fig. 6

eine Seitenansicht einer Kühlplatte mit einem bevorzugt ausgebildeten ersten Kühlplattenteil;

Fig. 7

einen Ausschnitt eines an einer Ofenwandung montierten Kühlsystems;

Fig. 8

den Längsschnitt A-A einer Kühlplatte nach Fig. 7;

Fig. 9

den in Fig. 8 dargestellten oberen Teilausschnitt in vergrößerter Darstellung;

Fig. 10

die in Fig. 8 dargestellten unteren Teilausschnitte in vergrößerter Darstellung.

Further details and advantages of the invention will become apparent from the dependent claims and from the following description in which the embodiments of the invention shown in the figures are explained in more detail. In addition to the combinations of features listed above, features alone or in other combinations are essential to the invention. Show it:

Fig. 1

a cross section of a cooling plate according to a first embodiment;

Fig. 2

a cross section of a cooling plate according to a second embodiment;

Fig. 3

a preferred trained second cooling plate part of Fig. 2;

Fig. 4

a longitudinal section of a mounted on a shaft furnace wall cooling plate;

Fig. 5

a partial section of a longitudinal section of a preferably formed first cooling plate member of FIG. 1;

Fig. 6

a side view of a cooling plate with a preferably formed first cooling plate part;

Fig. 7

a section of a mounted on a furnace wall cooling system;

Fig. 8

the longitudinal section AA of a cooling plate of FIG. 7;

Fig. 9

the upper part cutout shown in Figure 8 in an enlarged view.

Fig. 10

the lower part cutouts shown in Fig. 8 in an enlarged view.

Fig. 1 shows a cooling plate 1 and a Stavelet with a first cooling plate part 2, which faces the oven interior O _i , and a second rear cooling plate part 3, which are welded together. The welds 4 are on the protected, cold side of the cooling plate or Stavelets. Between the water-side rear side 5 of the first cooling plate part 2 as a rolled copper block and the water-side side 6 of the second cooling plate part 3 results in the cooling channel 7, which is fed with a cooling medium, preferably cooling water. For the water inlet and outlet pipe sections 8, 9 are mounted in bores in the second cooling plate part 3. The attachment of the cooling plate 1 to the furnace wall 10, for example, by means of a web 11 which is inserted into a holder 12 mounted on the furnace wall and is locked by means of a bolt 13 (see Fig. 4). The first cooling plate part 2 is designed as a solid rolling block with a flat - in the sense of non-curved - front side 14, in the transverse to the longitudinal axis of the cooling plate 1 extending grooves 15 are introduced, which facilitate the application of refractory stamping or spraying at the completion of assembly.

In the water-side 5 back of the first cooling plate part 2 or shield are two parallel to the longitudinal axis of the plate 1 extending, spaced apart, Recesses 16, 17 are introduced, each in about a semicircular Have cross-section. The cooling channel 7 becomes rearward, i. to Oven wall pointing, with a roughly flat or slightly outward arched second cooling plate part 3 closed in the sense of an additional part. It results in a cooling channel 7 with a cross-sectional area, wherein the end portions 18, 19 - seen in relation to the longitudinal extent (x-direction) - a larger Have cross-sectional area than the central region 20th

Another preferred embodiment of a cooling plate 101 with a claimed Cooling channel cross-section, Fig. 2. In this embodiment the desired cross section of the channel 107 - here the cross section perpendicular to the longitudinal axis of the cooling plate - by the shape of the second cooling plate part 103 determined. This is twice trough-shaped. By the curvature the troughs 121, 122 and the formation of a - here - short or longer center portion 123 is the desired cooling channel cross section with larger end areas 118, 119 compared to the center area 120 created the cross section.

To mechanically stabilize such a cooling plate 101, the trough-shaped second cooling plate part 203 and the copper sheet at its edge regions 324, 325 reinforced, i. thicker, as shown in Fig. 3. This is For example, by means of profile rollers possible.

Fig. 4 shows the longitudinal section of a cooling plate 1 in mounting position on the Oven wall, for example, the wall of a blast furnace. After locking the Cooling plate 1 by means of the bridge-holder principle is the remaining space between Cooling plate 1 and furnace wall 10 filled with backfill 26. The Pipe sections 8 and 9 are welded to the second cooling plate part 3 (27). The cooling channel 7 is closed by means of caps 28, 29 at the free ends.

A further preferred embodiment of the cooling plate 1, starting from the Embodiment of FIG. 1, is shown with Fig. 5. The massively trained first cooling plate part 1 is in the areas that the pipe sections 8, 9 for the Water inlet or outlet opposite, further hollowed out (cavities 30) so that the entrance or exit area increases. This cross-sectional enlargement Slowly - ramp-like - to the course of the cooling channel wells 16, 17 adapted. This has a positive effect on a reduction from cooling water pressure losses.

Because the second cooling plate member 3 so on the back of the first cooling plate member 2 is attached, that the edge areas 2a, b (or even fin areas) are not covered, there is a risk of waviness of the first Cooling plate part. This is done by inserting slots 31 in the edge areas 2a, b transversely to the longitudinal axis of the cooling plate, extending from the edge region 32 extend to approximately the second cooling plate part 3. by virtue of In the case of the slots, the edge areas can become thermally stress-free expand.

The cooling plates according to the invention are assembled into cooling systems. They are arranged, for example, immediately next to each other, wherein their stability supported by a tongue and groove principle in the first cooling plate parts can be. Alternatively, the edge regions of the first cooling plate parts also be arranged overlapping.

A section of such a cooling system 33 comprising a plurality of cooling plates 1 and Stavelets shows the Fig. 7, with the addition of another preferred Suspension system for the stavelets on the furnace wall 10 is shown. For this purpose, each cooling plate 1 or each Stavelet several suspension points 34-39, here six each, with the respective upper suspension points 34, 35 as benchmarks and the underlying suspension points 36-39 as Lospunkte are formed.

At the fixed points 34, 35 (see Fig. 8 and in particular Fig. 9) is a fixed Connection between the cooling plate 1 and the furnace wall 10 by screwing a screw 40 made from above. For this purpose, in each case a projection 41 on the furnace wall 10 and a corresponding projection 42 on the back the cooling plate 1 outside the cooling channel region - preferably through Welding - attached, have the appropriate holes and the over the screw 40 are connected together. The Lospunkte 36-39 are comparable to a door hanger, as shown in FIG. 10 in detail seen. For this purpose, the cooling plate at corresponding points on her Back turn provided with a bore projections 43 which in each protruding from the furnace wall pin 44, held by a Projection 45, to be hung. These Lospunkte 36-39 allow a thermal Expansion of the cooling plate 1 down. So that for the expansion required space at the suspensions or Lospunkten not by Hinterfüllmasse is blocked, at this point during assembly a lost part 46 made of plastic, preferably polystyrene, used.

Overall, a result due to the proposed cooling channel cross section aerodynamically as well as cooling technically optimized Stavelet, which to the known Stavelet also has manufacturing advantages. Compared to the well-known Cu-Staves are with these Stavelets because of the smaller Thick high material and weight savings achieved what moreover with a larger useful volume of the furnace area is accompanied.

Claims (12)

1. Cooling plate (1, 101) for shaft furnaces provided with a refractory lining, with a first cooling plate part (2, 102) which faces towards the furnace interior (O_i) as well as a second, rearward cooling plate part (3, 103), the parts being welded together, and with a cooling channel (7, 107), which extends between the first and the second cooling plate part, as well as with pipe sections (8, 9) for entrance and exit of coolant, characterised in that the first cooling plate part (2, 102) is constructed as a roll block with a planar front side (14) towards the furnace interior (O_i) and that the cross-sectional area of the coolant channel is greater in the end regions (18, 19; 118, 119) than in the centre region (20; 120) with respect to the longitudinal extent of the cross-section.
2. Cooling plate according to claim 1, characterised in that the end regions (18, 19; 118, 119) are outwardly curved on a half side or on both sides.
3. Cooling plate according to claim 1 or 2, characterised in that the cooling channel cross-section is formed on its side facing the furnace interior (O_i) by the first cooling plate part (2) with at least two depressions (16, 17) extending in the rear side (5) thereof.
4. Cooling plate according to one of claims 1 to 3, characterised in that the cooling channel cross-section is formed at the rear by an at least doubly, trough-shaped second cooling plate part (103) formed with outward curvatures facing the furnace wall.
5. Cooling plate according to claim 3, characterised in that the cooling channel cross-section is formed at the rear by an approximately planar second cooling plate part (3).
6. Cooling plate according to claim 4 or 5, characterised in that the second cooling plate part (103) is formed to be thicker in its edge region (324, 325) than in its centre region.
7. Cooling plate according to one of claims 1 to 6, characterised in that the second cooling plate part (3, 103) is welded by its longitudinal edges to the rear side (5) of the first cooling plate part (2, 102).
8. Cooling plate according to claim 7, characterised in that the second cooling plate (3) is welded, at a spacing from the edges (2a, b) of the first cooling plate (2), to the rear side thereof and at least one slot (31) is formed in the edge regions (2a, b) of the first cooling plate part (2) perpendicularly to the longitudinal axis of the cooling plate.
9. Cooling plate according to one of claims 3 to 8, characterised in that the pipe sections (8, 9) for the coolant inlet and exit project through bores in the second cooling plate part (3) at the rear side and that at the level of these pipe sections (8, 9) the first cooling plate part (2) is hollowed out and the depth of the hollowing (39) decreases in ramp-like manner to the cooling channel depressions (16, 17).
10. Cooling plate according to one of claims 1 to 9, characterised in that the cooling plate (1, 101) for the purpose of connection with the furnace wall (10) of the shaft furnace has at least two suspension points (34, 38), wherein a first suspension point (34) is formed as a fixed connection in the upper part of the cooling plate and a second suspension point (38) is formed as a detachable connection in the lower part of the cooling plate.
11. Cooling plate according to claim 10, characterised in that the first suspension point (34) comprises a screw connection as fixed connection and that the second suspension point (38) comprises a hook-in connection as detachable connection.
12. System (33) for cooling shaft furnaces provided with a refractory lining, comprising a plurality of cooling plates (1, 101), which are arranged adjacent to and/or above one another, of rolled copper or a rolled copper alloy according to one of claims 1 to 11.

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