CN110832104B

CN110832104B - Device and method for gas atmosphere separation

Info

Publication number: CN110832104B
Application number: CN201780091944.6A
Authority: CN
Inventors: 斯里德哈·巴莱普; 米夏埃尔·彼得斯; 安德列亚斯·韦斯特费尔德; 约阿希姆·许尔斯特龙
Original assignee: ThyssenKrupp Steel Europe AG; ThyssenKrupp AG
Current assignee: ThyssenKrupp Steel Europe AG; ThyssenKrupp AG
Priority date: 2017-06-12
Filing date: 2017-06-12
Publication date: 2021-11-23
Anticipated expiration: 2037-06-12
Also published as: WO2018228663A1; CN110832104A; EP3638822A1; EP3638822B1

Abstract

The invention relates to a device for separating a gas atmosphere in a sluice, said device extending in the transverse direction of the sluice, at least one blowing unit (1) and one suction unit (3) are arranged on the opposite walls, wherein the blowing-in unit (1) is provided directly opposite and the suction unit (3) is arranged downstream in the material flow direction (M), characterized in that the blowing-in units (1) each comprise at least two rows of slot nozzles (2), each row consisting of a plurality of slot nozzles (2) with spaces between them, wherein the slot nozzles (2) of each row are arranged offset from one another and the spacing therebetween is shorter than the slot nozzles (2) of the adjacent row, the slot nozzles (2) of a row thereby overlapping in the material flow direction (M), and the slit nozzles (2) of the blowing units (1) are respectively arranged opposite to the interval of the opposite blowing units (1).

Description

Device and method for gas atmosphere separation

Technical Field

In the field of continuously processing materials, a partial gas atmosphere can be distinguished from its neighboring gas atmosphere. The difference can be in different gas compositions or vapors, dust or particles resulting from the process, which may load the gas atmosphere or affect the products.

Background

An installation for the continuous hot dip galvanizing of steel strip, for example, is composed in particular of a through-annealing furnace, a zinc bath (molten bath), a device for adjusting the thickness of the zinc coating and a subsequent cooling device. The steel strip is continuously annealed in the through-furnace, which is divided into a plurality of chambers in which different treatments are carried out. These treatments here include adjusting the desired mechanical properties of the base material, for example by recrystallization of the steel. Wherein the iron oxide formed in the preheating zone is additionally reduced. In the cooling zone after the through-annealing furnace, the strip is cooled to a temperature close to the bath temperature under a protective gas (HNX). The shielding gas should prevent the annealed strip from being oxidized before galvanising, thereby significantly deteriorating the adhesion of the zinc layer. Due to the different treatments, different gas atmospheres are also partially required in the chamber. The connection piece or the gate between the annealing furnace and the zinc bath containing the protective gas is called a tuyere stock.

In conventional furnace tuyere stock, continuous strip galvanizing facilities often suffer from zinc dust precipitation, especially when vibrations occur in the facilities which fall in large pieces onto the zinc bath and/or the steel strip and thereby cause surface defects (galvanizing defects). It is known that a steel strip moving in the direction of the zinc bath drags the protective gas downwards in the tuyere stock, wherein the dragged protective gas is applied to the zinc vapor on the surface of the zinc bath, which condenses or re-sublimes on the cold inner walls of the tuyere stock in the rising of the dragged protective gas and deposits there as dust.

From JP H07-157853(a) an apparatus for removing zinc vapour in a tuyere stock of a continuous strip zinc plant is known. In order to remove zinc vapor generated on the surface of the zinc bath, a tuyere stock having a blowing port (circulation port) and a suction port arranged vertically downward is provided. In the first embodiment, a single blowing port and a single suction port directed vertically downward are arranged in the tuyere stock wall facing the upper side of the steel strip. Correspondingly, a single blowing-in opening and a single suction-out opening directed vertically downwards are likewise arranged in the tuyere stock wall facing the lower side of the steel strip. In a second embodiment, a single blowing-in opening is arranged on the side wall of the tuyere stock while two suction outlets directed vertically downwards are provided, which are designed as longitudinal slits in the tube, which penetrate the side wall of the tuyere stock and project over the entire steel strip width on the upper and lower sides of the steel strip. However, an insufficient sealing of the gaseous atmosphere with or without zinc dust is disadvantageous for such embodiments.

Another example of a tuyere stock region from a galvanizing device is known from DE102012106106a 1. The region with the plurality of blowing openings is adjacent to the region with the plurality of suction openings, which are at least partially comb-staggered with respect to one another. A relatively good tightness of the ascending zinc vapour with respect to the gas atmosphere above it is thus obtained. However, such devices are relatively expensive to manufacture and are associated with high floor space requirements. Further hindrance to the quality of the product can occur due to the high saturation of the zinc vapour in the gas atmosphere created by the sealing before immersion.

Disclosure of Invention

The invention is therefore based on the object of providing a device and a method which can effectively avoid the influence of an adjacent gas atmosphere, in particular the backflow. A further object of the invention is to provide advantageous manufacturability, a smaller footprint and easy installation.

This object is achieved by a device according to the features of claim 1, in particular when using a method according to the features of claim 11.

According to the invention, a device for separating a gas atmosphere in a lock is proposed, which has at least one blowing unit and one suction unit in each case on opposite walls in the transverse extension of the lock, wherein the blowing units are provided directly opposite one another and the suction units are arranged downstream in the flow direction of the material, characterized in that the blowing units each comprise at least two rows of slotted nozzles, each row comprising a plurality of slotted nozzles with spaces between them, wherein the slotted nozzles of each row are arranged offset from one another and wherein the spaces are shorter than the slotted nozzles of the adjacent row, the slotted nozzles of each row thereby overlapping in the flow direction of the material, and the slotted nozzles of the blowing units each lie opposite the spaces of the opposite blowing units. The blowing units are therefore placed on both sides of the material transported through the sluice, preferably on both sides of a continuous material track, for example a steel belt, wherein the invention can also be used for transporting single goods (St ü ckgut). The use of slotted nozzles can be optimized by the arrangement of the rows and the spacing in the rows, since the beam divergence (Strahlaufweitung) occurring in the gas streams emerging from adjacent slotted nozzles does not interfere in opposition and a closed gas curtain is formed by this arrangement. A tight curtain of air is formed in the central region of the lock (where the blown air streams meet one another) by the slot nozzles of the blowing units which are likewise arranged offset with respect to the slot nozzles of the opposite blowing units or the spacing. Excellent separation of the gaseous atmosphere is thus obtained, even outside the material track or between single pieces of goods.

A further embodiment of the apparatus according to the invention is characterized in that the suction unit has a main opening arranged extending in the transverse direction, wherein the main opening is aligned with the material flow direction to generate a circulatory flow. The main opening is thus placed on the distal side of the insufflation unit, thereby facilitating entrainment of insufflation gas in the direction of material flow and circulation of the gas atmosphere. It is thereby possible, for example, to suck out the zinc dust units together in the tuyere stock and subsequently filter them in order to obtain a gas atmosphere which is as "cleaner" as possible.

In a preferred embodiment of the device, the blowing unit and the suction unit are each connected to at least one central line for feeding in or out gas. This makes it possible to keep the flow conditions as constant as possible over the width of the insufflation unit and the aspiration unit.

In a particularly preferred embodiment of the device, the main opening in the region of the central duct has a greater height. By such a design, the fluid ratio is maintained more consistently across the width, which improves aspiration.

A further embodiment of the device is characterized in that the aspiration unit comprises additional ports perpendicular to the direction of flow of the material. This additional port improves the pressure ratio in the gate and reduces the fluid velocity at the opening of the aspiration unit, which has advantages in terms of noise generation and wear.

In an embodiment of the apparatus, the slot nozzle is characterized in that the slot nozzle has a width b, the distance a between the rows is in the range b ≦ a ≦ 2 ≦ b, and the overlap u of the slot nozzle in the material flow direction is in the range b ≦ u ≦ 3 ≦ b, wherein in addition a ≦ u. In order to obtain as good a separation of the gas atmospheres as possible, the slot nozzles are not allowed to have too large a distance from one another. It is shown here that good results are obtained when the minimum distance between the rows is the same width as the width of the slot nozzle and when the distance is greater than double the width, the risk of the gas flows separating and worse separation increases.

A preferred embodiment of the device is characterized in that the slot nozzle has a length l in the transverse direction, wherein the length l is in the range of 20 & ltb & lt l & gt, 50 & ltb & gt, preferably in the range of 30 & ltb & lt l & gt, 35 & ltb & gt.

The device according to the invention is characterized in a further embodiment in that an additional blowing unit is arranged upstream in the material flow direction. The separation of the gas atmosphere is further improved by this additional blowing unit and a subsequent backflow of the gas atmosphere is reliably avoided.

In a further embodiment of the device, the blowing unit and/or the suction unit are divided laterally into a plurality of sections, wherein each section comprises its own intermediate line for feeding or discharging the gas. By such a division, preferably in equal-width sections, the fluid ratio over the width of the sluice can be further improved and additionally the required capacity per pipe can be reduced.

An embodiment of the device is characterized in that the insufflation unit and/or the aspiration unit have a semicircular cross section. The cross section of the fillet has a geometry which is advantageous in terms of flow technology. Furthermore, the cross section to be sealed of the sluice is reduced by means of a blowing unit or a suction unit placed on the sluice wall.

The device according to the invention is preferably operated by a method for separating a gas atmosphere in a sluice, which method is characterized in that a larger gas volume flow is drawn off by the suction unit than a gas volume flow introduced by an adjacent blowing unit. The volume flow withdrawn here is approximately 15% to 20% greater than the volume flow introduced by the adjacent blowing unit. This produces a negative pressure in the atmosphere downstream in the material flow direction, which, together with the gas curtain of the blowing unit, ensures as far as possible that no backflow takes place in the gas atmosphere already running.

An embodiment of the method according to the invention is characterized in that the additional volume flows are introduced by means of an additional blowing unit arranged upstream in the material flow direction, wherein the sum of the introduced volume flows corresponds to the aspirated volume flow. As already explained for the device, the additional volume flow of the additional blowing-in unit improves the separation of the gas atmosphere, since a pressure equalization for the adjacent sections or the gas atmosphere is achieved by the additional volume flow. While the exit of the gas atmosphere upstream in the flow direction of the material is largely avoided by the balancing of the blowing-in suction and the suction-out volume flow.

A preferred embodiment of the method is characterized in that a volume flow which is increased by a factor of two to four, preferably by a factor of three, is introduced by the blowing unit adjacent to the aspiration unit relative to the additional blowing unit. The separation of the gas atmosphere is thereby achieved by the aspiration unit and the adjacent blowing unit and the possible detachment of the gas atmosphere is carried out by the additional blowing unit (Entkopplung).

In an embodiment of the method, the incoming volume stream is preheated, preferably to a temperature of 450 ℃ to 550 ℃. In particular in the use in through-furnaces, galvanizing plants and other plants with elevated temperatures, it is particularly advantageous when the blown-in gas is heated to a corresponding temperature so as not to interfere with the temperature control or thermal treatment of the material and to avoid condensation of the gaseous atmosphere components. For use in the tuyere stock of the galvanizing apparatus, the temperature is preferably in the range of 450 ℃ to 550 ℃, for example.

The use of the device according to the invention operating with the method described takes place in a tuyere stock of a hot coating installation for the separation or discharge of metal vapors.

Further uses of the device according to the invention may for example take place in a through-furnace for the separation of different gas atmospheres.

Apart from the examples described, the device according to the invention can also be used in other fields, in which the gas atmospheres are separated from each other in a continuous process.

Drawings

The invention will be explained in more detail below by means of a schematic drawing, in which similar components are provided with the same reference numerals. And (3) displaying in detail:

FIG. 1: a schematic view of the blowing unit, viewed perpendicular to the material flow direction,

FIG. 2: embodiments of the aspiration unit, and

FIG. 3: the gate according to the invention, viewed perpendicular to the direction of material flow.

Detailed Description

Fig. 1 shows schematically a blowing-in unit (1) according to the invention, the view being perpendicular to the material flow direction, more precisely to the plane of the transported material. Two rows of slot nozzles (2) are shown, each having a space or intermediate space between the respective slot nozzles (2). The slot nozzles (2) each have a width b and a length l. The two rows of slot nozzles (2) are each at a distance a from one another in the material flow direction. The slot nozzles (2) of adjacent rows are offset from one another in such a way that the spacing of one row enables one slot nozzle (2) of an adjacent row to be arranged. The slot nozzles (2) are designed to be longer than the spacing between the slot nozzles, so that an overlap u of the ends of the slot nozzles (2) occurs, as seen in the material flow direction. The overlap u is formed identically along the blowing unit.

In fig. 2, partial areas are shown, in which parts of the lower blowing unit (1) and the aspiration unit (3) and of the upper blowing unit (1) and aspiration unit (3) in the sluice according to an exemplary embodiment are shown. Two blowing units (1) are shown facing each other on the upper and lower walls of the sluice and a suction unit (3) downstream, i.e. downstream, in the direction of material flow. In this illustration, it can be seen that the individual slot nozzles (2) of the blowing unit (1) are arranged offset from one another. In addition to the offset between the rows of blowing units (1) as already shown in fig. 1, fig. 2 also shows the offset of the slot nozzles (2) for the opposite blowing units. In the embodiment shown, in the lower blowing unit (1), the outermost slot nozzles (2), viewed in the width direction of the gate, are arranged in the front, i.e. upstream, row, while the rear, i.e. downstream, row starts at a distance. Correspondingly, in the upper blowing unit (1), the outermost slot nozzles (2) are arranged in the later rows and start at a distance from the earlier rows. By this arrangement, it is achieved that the gas flow emerging from the slot nozzle (2) reaches the opposite lock wall, more precisely the opposite blowing unit (1) or the material surface, in the main direction of its extent without hindrance, and that the contact of the gas flow takes place only in the unavoidable beam expansion region. By such a design a very stable gas curtain with a very good sealing action is obtained.

In the embodiment illustrated in fig. 2, both the suction unit (3) and the blowing unit (1) are divided into a plurality of regions as viewed in the width direction by intermediate walls (8). For the gas discharge or supply to the suction unit (3) or the blowing unit (1), the suction unit and the blowing unit each have a line (6), which in fig. 2 each represents a line (6) via a circular connection opening. Furthermore, in the exemplary embodiment shown, the insufflation unit (1) and the aspiration unit (3) are each designed with a semicircular cross section, which has advantages in terms of flow technology by avoiding sharp edges.

Fig. 2 additionally shows a preferred embodiment of the aspiration unit (3). The main opening (4) is aligned with the material flow direction M in order to generate a circulating flow after the device. The main opening (4) in the region of the duct (6) is designed here with a greater height in order to achieve a relatively homogeneous flow ratio over the width. The height of the main opening (4) can be changed here continuously or else, as in the embodiment shown, in a jump. An additional port (5) is preferably provided on the upper side of the aspiration unit (3). This additional opening also makes it possible to reduce the area of the circulating flow in addition to improving the suction, which reduces the required installation space for the sluice and facilitates the circulating flow. The additional openings can be designed with a uniform height over the width of the aspiration unit or likewise with different heights similarly to the main opening (4). In this embodiment, the blowing-in unit (1) and the suction unit (3) can be designed, for example, with a radius of 40mm in the tuyere stock of the thermal coating apparatus, and the height of the main opening (4) is, for example, in the range of 10 to 15mm, and the height of the additional opening (5) is about 8 mm. The pipe (6) can be designed in this embodiment with a diameter of approximately 60 mm.

Figure 3 shows a top view of an embodiment of a gate according to the present invention. The blowing unit (1) and the suction unit (3) located downstream in the material flow direction M are shown here. Furthermore, an additional blowing unit (7) is shown, the additional blowing unit (7) being at a distance from the blowing unit (1). The distance between the blowing unit (1) and the additional increasing unit (7) is preferably in the range between the width of the sluice and twice the width of the sluice. In the embodiment of the tuyere stock of the thermal coating device with a tuyere stock width of about 1.9m, the additional blowing-in unit is therefore preferably arranged at a distance of 2m to 3m from the blowing-in unit (1).

The different features of the invention can be combined with one another as desired and are not limited to the embodiments of the embodiments described or shown.

Reference number Specification 1 blowing Unit

2. Slit nozzle

3. Suction unit

4. Main opening

5. Additional port

6. Pipeline

7. Additional blowing unit

8. Intermediate wall

a distance

b width of

length l

u overlap

M material flow direction

Claims

1. A device for separating a gas atmosphere in a sluice, said device extending in the transverse direction of the sluice, at least one blowing unit (1) and one suction unit (3) are arranged on the opposite walls, wherein the blowing-in unit (1) is provided directly opposite and the suction unit (3) is arranged downstream in the material flow direction (M), characterized in that the blowing-in units (1) each comprise at least two rows of slot nozzles (2), each row comprising a plurality of slot nozzles with spaces between them, wherein the slot nozzles (2) of a row are arranged offset from one another and the spacing therebetween is shorter than the slot nozzles (2) of an adjacent row, the slot nozzles (2) of a row thereby overlapping in the material flow direction (M), and the slit nozzles (2) of the blowing units (1) are respectively arranged opposite to the interval of the opposite blowing units (1).

2. The device according to claim 1, characterized in that the aspiration unit (3) has a main opening (4) arranged extending in a transverse direction, wherein the main opening (4) is aligned with the material flow direction (M) to generate a circulatory flow.

3. Device according to claim 1 or 2, characterized in that the blowing unit (1) and the suction unit (3) are each connected to at least one central duct (6) for feeding or discharging gas.

4. Device according to claim 3, characterized in that the main opening (4) in the region of the central duct (6) has a greater height.

5. Device according to claim 1, characterized in that the aspiration unit (3) comprises an additional port (5) perpendicular to the material flow direction (M).

6. The device according to claim 1, characterized in that the slot nozzles (2) have a width b, the distance a between the rows being in the range b ≦ a ≦ 2 ≦ b, and the overlap u of the slot nozzles (2) in the material flow direction (M) being in the range b ≦ u ≦ 3 ≦ b, wherein further a ≦ u.

7. The device according to claim 6, characterized in that the slotted nozzle (2) has a length l in the transverse direction, wherein the length l is in the range of 20 x b ≦ l ≦ 50 x b.

8. The device according to claim 6, characterized in that the slotted nozzle (2) has a length l in the transverse direction, wherein the length l is in the range of 30 x b ≦ l ≦ 35 x b.

9. Device according to claim 1, characterized in that an additional blowing unit (7) is arranged upstream in the material flow direction (M).

10. Device according to claim 1, characterized in that the blowing-in unit (1) and/or the suction unit (3) is divided laterally into a plurality of sections, wherein each section comprises its own central duct (6) for feeding in or feeding out gas.

11. Device according to claim 1, characterized in that the insufflation unit (1) and/or aspiration unit (3) has a semicircular cross section.

12. Method for separating a gas atmosphere in a sluice, wherein a device according to one of claims 1 to 11 is used, characterized in that a larger gas volume flow is sucked out by a suction unit than the gas volume flow introduced by an adjacent blowing unit (1).

13. Method according to claim 12, characterized in that further volume flows are introduced by means of an additional blowing unit (7) arranged upstream in the material flow direction (M), wherein the sum of the introduced volume flows corresponds to the aspirated volume flow.

14. Method according to claim 12, characterized in that a volume flow increased by a factor of two to four compared to the additional blowing unit (7) is introduced by the blowing unit (1) adjacent to the aspiration unit (3).

15. Method according to claim 12, characterized in that a volume flow increased by three times compared to the additional blowing unit (7) is introduced by the blowing unit (1) adjacent to the aspiration unit (3).

16. Method according to claim 12, characterized in that the incoming volume flow is preheated.

17. The method according to claim 12, characterized in that the incoming volume flow is preheated to a temperature of 450 to 550 ℃.

18. Use of a device according to any one of claims 1 to 11 for the separation and evacuation of metal vapors in a tuyere stock of a hot coating installation, said device operating according to the method of any one of claims 12 to 17.

19. Use of a device according to any one of claims 1 to 11 in a through-furnace for separating different gas atmospheres, the device operating according to the method of any one of claims 12 to 17.