EP1155154B1 - Blow form for shaft furnaces, especially blast furnaces or hot-blast cupola furnaces - Google Patents

Description

The invention relates to a blow mold for shaft furnaces, in particular blast furnaces or Hot-wind cupola furnaces according to the preamble of patent claim 1.

Parts of this type, largely cast from copper or a copper alloy Manufactured, water-cooled blow molds are widely used to feed the Hot wind used to operate the shaft furnace effectively to back up. In the case of a blast furnace, the temperature of the hot mixing wind is in the Range from approx. 700 to over 1300 degrees Celsius at pressures between 2.5 and 5.5 bar. It is not only the inner shell of the blow mold, and here in particular that Front part, heavily used, but also with progressive wear of the Refractory lining of the shaft furnace and thus exposing the front area the blow mold increasingly the jacket area through melting phases such. B. pig iron, Slag, partially reduced waste and zinc, as well as through abrasion with coke and / or Wind. To ensure a sufficient service life under these extreme stresses reach, it is necessary to blow the mold by intensive cooling by means of a coolant passed through them, mostly cooling water, to tolerable temperatures to keep. It also requires the surface wear of the blow mold due to corrosive effects of melting phases and abrasion by suitable Minimize measures.

A blow mold for shaft furnaces is known from DE-OS 35 05 968. At this Construction is on a base part of an inner and an outer jacket and an existing double-walled front part connected to it Hollow body attached. The cavity formed between the inner and outer jacket becomes through an intermediate wall arranged in the front part area into a front wall and a front wall Subsequent main chamber divided. A feed line arranged in the base part for the coolant extends as a tube through the main chamber and the intermediate wall to the antechamber. The partition has several openings, so that the Coolant can flow back from the antechamber to the main chamber. From there flows it via openings arranged in the base part in an annular chamber, which with a Return connection is provided. The disadvantage of this construction is that the Blow mold is cooled with only one cooling circuit system and in the event of cooling failure or when there are leaks in the blow mold and as a rule required throttling of the cooling water amount so heavily used is that it will be destroyed in a short time with all resulting from it Consequences and dangers. Another disadvantage is that the cooling water is not led in several places, so that turbulence occurs, which promote vapor bubble formation and thus heat dissipation from them Places is greatly reduced. In extreme cases, this can lead to local melting and melting thus lead to the destruction of the blow mold.

A further development of the blow mold is known from US 2,735,409. At this known embodiment is the hollow body in a lying in the front portion Antechamber and an adjoining main chamber divided, the antechamber and Main chamber are completely hydraulically separated and one each have a separate coolant circuit with its own connections. The The coolant circuit of the main chamber consists of an outer jacket helically tightly wound tube while the coolant circuit of the Antechamber consists of two parallel straight tubes that are U-shaped trained ring channel of the front part open. In a first embodiment the inner jacket is designed as a smooth conical tube, the two straight Pipes of the prechamber between the inner and outer jacket are arranged. At a second embodiment, the inner jacket is also made of a screw tightly wound tube formed. The front part is manufactured as a separate part and either via anchors with the rear connection part or directly via one The weld seam is connected on the face to the inner and outer jacket. A disadvantage of This well-known construction is very small due to its design and less favorable Querform (rectangle) designed cooling channels in the main chamber area, as well as the very small cross-sections in the feed lines to the pre-chamber due to the design. The in relation to a reduction in cross-section and in relation to an increasing one Deviation from the round cross-sectional shape disproportionate decrease in Coolant volume flow in both the front and the main chamber has one a correspondingly clear deterioration in the cooling effect. From further The disadvantage is that according to the description of the above-mentioned font Cross section of the prechamber cooling duct should be as small as that of the Main chamber cooling channel. This results in a cross-sectional shape rectangular prechamber cooling duct with very unfavorable aspect ratios and one resulting poor cooling effect. Also the mouth of the inlet channel in the prechamber cooling duct is disadvantageous as this is high hydraulic Resistance in this cooling circuit means with the resulting lower Cooling medium volume flow or lower cooling medium speed in the Antechamber and the resulting poor cooling effect. The Overall construction is very expensive to manufacture and has a variety of critical sealing points that are partially undissolved. This is also unsolved Problem of external attack of the main chamber of the known blow mold dripping melting phases in the blast furnace.

The object of this invention is to provide a blow mold of the aforementioned type create that with reasonable effort for the production by a thermally highly stressed front part area extremely effective cooling a disproportionate long service life and thus low operating costs as well as an affordable one Operational behavior of the shaft furnace equipped with it ensures without the Available cooling water quantities and differential pressures are crucial change. Another task is to blow the blow by one Favorable geometric design as far as possible before dripping To protect melting phases in the shaft furnace and, as a rule, not completely thermally so heavily used main (back) chamber also with an extremely effective To provide cooling without the available cooling water quantities and Differential pressures, as well as the directly related operating costs for the To change cooling water decisively.

This task is based on the generic term in conjunction with the characterizing features of claim 1 solved. advantageous Further training is the subject of subclaims.

The essence of the invention is the formation of the outer shell by a one-piece, in Cross section seen vertical axisymmetric body, the front passes seamlessly into the front part. The inner jacket is formed by a conical trained welded part, which the inner cover of the helical formed cooling channel of the main chamber. Another important feature is the arrangement of the channels supplying the front part with cooling medium in the 12 o'clock position the blow mold, based on the longitudinal axis of the blow mold, outside the cross section of the main chamber. With the proposed arrangement The cooling channels in the pre-chamber will show the different loads on the blow mold Considered circumferential direction considered. This is how the blow mold is proven more stressed in the 12 o'clock position than in the side areas. Because of the intense Cooling this stressed area becomes significant the life of the blow mold elevated. Optionally, the coolant circuit of the main chamber can be a two-course system helical cooling channel formed or with a helical Cooling duct and a straight cooling duct lying in the blow mold at 6 o'clock be provided. The straight one, lying parallel to the blow axis and without ribs provided cooling channel is, based on the longitudinal axis of the blow mold outside the original cross section of the main chamber of the blow mold, the Connections for the flow and return adjacent to the connections of the antechamber are in the 12 o'clock position. With the arrangement of the straight cooling duct in the 6 o'clock position the different load of the blow mold in the blow mold Circumferential direction taken into account. In addition to the 12 o'clock position, the blow mold is also in the 6 o'clock position more stressed than in the side areas. Because of the intense Cooling this area also increases the service life of the blow mold.

As already mentioned, the proposal provides for the inflow and outflow channels for the Antechamber and the return duct of the main chamber from the area of the Lay out cross section of the main chamber of the blow mold in each case in the radial direction outside the main chamber, based on the longitudinal axis the blow mold. This ensures that none in the cooling channel of the main chamber Cross-sectional narrowing caused by inlet and return channels. Because of that there are optimal fluidic conditions in the main chamber greatest possible coolant speeds. Furthermore, all channels mentioned seen over the length almost a constant cross-section and the required cross-sectional changes in the connection area and the small-wheeled Changes of direction are rounded and without jump points.

With these measures, flow rates for the Coolants achieved that are at least twice as high as those known versions. This is achieved by avoiding dead zones, Swirling points, throttling points, storage areas as well as the optimal Possibility of designing the cooling channel cross-sectional shapes (round, trapezoidal) and the Cross-sectional size of the individual channel sections. The optimal design option of the inlet and return channels for the prechamber leads with unchanged Differential pressure also in the antechamber at significantly higher flow rates. If you continue to ensure that a balanced ratio of Pump output and channel cross section the desired high flow rates can be achieved, then the vapor bubble formation largely suppressed. The aim is also at low available Differential pressure of, for example, 2 bar for cooling the highly loaded Antechamber a flow rate of ≥ 10m / sec and for the main chamber of ≥ 6m / sec. The proposed blow mold design is for both prechambers with only one ring channel as well as for longer antechambers with a helical one Channel suitable.

US-A-3 601 384 describes a blow mold having a one-piece, a helical shape Outer jacket containing cooling channel, which with a covering the cooling channel Inner jacket is welded. The axially parallel channels for the supply and discharge of the However, coolants to the cooling channel are not arranged as in the invention and only one coolant circuit is provided.

However, as already mentioned at the beginning, the blow mold is not only thermal, but also also additionally chemically and mechanically loaded; especially if the Wear of the refractory lining of the shaft furnace a certain degree has reached. For this purpose, the cross section of the blow mold in the 12 o'clock position area is proposed according to the invention to train as a roof. This has the advantage of falling on the blow mold or dripping substances can slide off or drain off more easily. This training is supposed to in particular the undesired contacting of liquid zinc, pig iron or Reduce slag with the blow mold made of copper or copper alloy. As is known, zinc reacts with copper, making the copper wall chemically is reduced.

Figur 1

einen Längsschnitt in Richtung A-A in Figur 2 durch eine erfindungsgemäß ausgebildete Blasform

Figur 2

eine Seitenansicht in Richtung X von Figur 1

Figur 3

einen Schnitt in Richtung B-B in Figur 1

In the drawing, the blow mold designed according to the invention is explained in more detail using an exemplary embodiment. Show it:

Figure 1

a longitudinal section in the direction AA in Figure 2 through a blow mold designed according to the invention

Figure 2

a side view in the direction X of Figure 1

Figure 3

a section in the direction BB in Figure 1

The blow mold designed according to the invention consists of an outer jacket 2 forming base body 1 and a weld-in part 4 forming the inner jacket 3. The hollow body that forms between the outer jacket 2 and the inner jacket 3 becomes completed at the front by a thermally highly stressed front part 5. On the input side, the base body has a double-conical inlet section 6, in the nozzle tip of a nozzle block, not shown here, is inserted. in the The upper part of the inner jacket 3 is arranged on the inner jacket 3 Refractory layer 7 shown hinted. The frontal area of the Front part 5 is provided with armor 8 to the front part 5 before mechanical Protect damage and wear. As is known, the one with coolant acted upon hollow body divided into a prechamber 9 and a main chamber 10. Both chambers 9, 10 are hydraulically completely separated from each other and on separate cooling circuits connected.

According to the position of the section in A-A in FIG. 2, the upper part of FIG To recognize the blow shape of the inlet channel 11 for the prechamber 9. Is on the inlet side the inlet channel 11 with a connection 12 in the form of a threaded section provided, into which an inlet pipe, not shown, can be screwed. The Inlet channel 11 then merges into the prechamber 9, which is transverse to the Inlet channel 11 lying ring channel 22 is formed. Instead of a ring channel, too the arrangement of a helical design having a plurality of revolutions Channel possible.

In Figure 2 it can be seen that in the 12 o'clock position of the blow mold parallel to Inlet channel 11, the return channel 13 for the prechamber 9 is arranged. He is likewise with a connection 14 arranged on the end face in the form of a Provide threaded portion in the drain pipe, not shown here can be screwed in. The location of the two channels 11, 13 is particularly good according to the Recognition in Figure 3.

So that the coolant is also fluidically efficient in the main chamber 10 is guided, this has a helical cooling channel 15. The The inside of this cooling duct 15 is covered by the inner jacket 4 The coolant is supplied or discharged into the main chamber 10 in the 11 o'clock or 1 o'clock position area, adjacent to the connections 12, 14 for the prechamber 9. Im Seen clockwise behind the inlet connection 18 arranged in the 1 o'clock area is the coolant through a semicircular channel 20 (with dashed lines in Fig. 2 Lines shown) in the double-conical inlet section 6 to the 6 o'clock position guided below and enters the helical cooling channel 15 here. After this Passing through the helical cooling channel 15, the cooling medium comes directly in front Antechamber 9 into a return channel 16, which is also arranged at 6 o'clock, the is below the helical cooling channel 15 and the cooling medium returns into the double-conical inlet section 6. In the double-conical inlet section 6 the cooling medium is again in a semicircular channel 21 (in FIG dashed lines) in the 11 o'clock position up to the drain connection 17 out. The two cooling channels 15, 16 for the main chamber 10 are at the end also provided with a threaded section 17, 18 into which the inlet or outlet pipe is screwed in. The inlet and return connection 12,14,17,18 for both Antechamber as well as for the main chamber are interchangeable without affecting the desired effect of an intensive cooling effect changes somewhat.

According to the invention, the cooling channels 11, 13 for the prechamber 9 or the ring channel 22 are approximately the same in cross section, but smaller than the cross sections F1, F2 of the cooling channels 15, 16 of the main chamber 10 F4 = F5 <F1 = F2.

The cross-sectional transitions and the small-scale changes in direction of the channels are very rounded, so that there are no turbulence points or dead zones can.

The additional chemical and mechanical stress that occurs the blow mold is strongly influenced by the geometric shape. The hollow body is tapered towards the shaft furnace, with a half Cone angle in the range of 12 - 14 ° has been found to be favorable. In the same According to the invention, the roof-like configuration 19 of the 12 o'clock position area also has a directional effect to see the blow mold. Substances falling or dripping on the blow mold the shaft furnace or the loading can thus be moved sideways in a simple manner and slide or flow towards the center of the shaft furnace.

Claims (12)

1. Blow form for shaft furnaces, in particular blast furnaces or hot-blast cupola furnaces, consisting of a conical hollow body with an inner (4) and an outer casing (2) and a front end part (5) joining the same without a shoulder, through the inner casing of which the hot blast to be fed to the shaft furnace is conducted and through whose cavity formed between the inner and outer casing a coolant flows during operation, the cavity being divided respectively into an antechamber (9) lying in the front end region and an adjoining main chamber (10), which are hydraulically fully separate from one another and each have a separate coolant cycle with their own terminals, wherein the coolant cycle for the antechamber (9) consists of two channels (11; 13) of almost constant cross-section, which are disposed parallel to the blow form longitudinal axis, which form the supply and return, and which open in the front end part (5) into an annular channel disposed transverse to the channels (11; 13), and the coolant cycle of the main chamber (10) is provided with a helical coolant channel (15) of almost constant cross-section viewed over the length, characterised in that the outer casing (2) is formed by a one-piece base body (1), which has a vertical axis of symmetry viewed in cross-section, and the inner casing (3) is formed by a conical welded-in part (4), which covers the coolant channel (15) of the outer casing (2) on the inside, and the channels (11, 13) supplying and discharging the coolant to the front end part (5) are disposed in the 12 o'clock position region of the blow form and outside the part of the cross-section of the outer casing (2) provided with the coolant channel (15) relative to the longitudinal axis of the blow form.
2. Blow form according to claim 1, characterised in that the helical coolant channel of the main chamber (10) is double, in which case one helical coolant channel forms the supply and the other helical coolant channel the return, and both helical coolant channels are joined together by a 180-degree deflection.
3. Blow form according to claim 1, characterised in that the coolant cycle of the main chamber (10) has a straight coolant channel (16) in the 6 o'clock position of the blow form and the straight coolant channel (16), lying parallel to the blow form longitudinal axis and provided without fins is disposed outside the original cross-section of the main chamber (10) of the blow form relative to the longitudinal axis of the blow form, in which case the terminals (17, 18) for the supply and return are disposed adjacent to the terminals (12, 14) of the antechamber (9) in the 12 o'clock position region.
4. Blow form according to one of claims 1-3, characterised in that the cross-sectional shape of the channel of the antechamber (9) lying in the longitudinal axis is round, and that of the helical channel (15) of the main chamber (10) is approximately trapezoid with rounded corners.
5. Blow form according to one of claims 1-4, characterised in that the cross-sectional changes necessary for all channels (11, 13, 15, 16) of the antechamber (9) and the main chamber (10) are rounded and without irregularities in the connecting region and the small-radius changes of direction.
6. Blow form according to claim 3, characterised in that two channels (20, 21) extending in a semi-circular manner and connected to the terminals (17, 18) are disposed in the double-conical inlet section (6) and are guided downward into the 6 o'clock position region and are hydraulically fully separated from one another in the 12-hour and in the 6 o'clock position region and form the connection with the helical coolant channel (15) of the main chamber (10), in which case at the front end of the helical coolant channel (15), the straight coolant channel (16) directly abuts the partition wall with the antechamber (9) and lies under the helical coolant channel (15) in the 6 o'clock position region and opens at the end face back into the double-conical inlet section (6).
7. Blow form according to one of claims 1-6, characterised in that the cross-sections (F4) of the supply and return channel (11, 13) for the antechamber (9) and the cross-section (F5) of the annular channel (22) in the antechamber (9) are almost the same size, but smaller than the cross-sections (F1, F2) of the coolant channels (15, 16) of the main chamber (10).
8. Blow form according to one of claims 1 and 3-7, characterised in that the straight coolant channel (16) of the main chamber (10) has a cross-section (F1) which is almost the same size as that of the helical coolant channel (15) of the main chamber (10).
9. Blow form according to claims 7 and 8, characterised in that the cross-sections (F4, F5) of the coolant channels (11, 13, 22) of the antechamber (9) are smaller by up to 35% than the cross-sections (F1, F2) of the coolant channels (15, 16) of the main chamber (10).
10. Blow form according to claims 7-9, characterised in that at roughly the same pumping power for the coolant supply of the antechamber (9) and main chamber (10), the flow rate in the coolant channels (15, 16) of the main chamber (10) is at least 60% of the flow rate in the coolant channels (11, 13, 22) of the antechamber (9).
11. Blow form according to claim 10, characterised in that with a coolant differential pressure at the blow form of 2 bar, the speed of the coolant in the coolant channels (11, 13, 22) of the antechamber (9) is at least 10m/sec and in the coolant channels (15, 16) of the main chamber (10) at least 6 m/sec.
12. Blow form according to one of claims 1-11, characterised in that viewed in cross-section the blow form is formed in the 12 o'clock position region as a roof and in the 6 o'clock position as a convexity, and the coolant channels (11, 13) of the antechamber (9) are disposed in the roof-like region, and the straight coolant channel (16) of the main chamber is disposed in the convex region.

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