A low compression ratio hot-rolled steel continuous galvanizing heating device

Abstract

The utility model discloses a low compression ratio hot-rolled steel continuous galvanizing heating device, which belongs to the field of galvanizing heating, and comprises a heating section, a soaking section, a cooling section, a balancing section and an outlet section connected in sequence; wherein the heating section is provided with a plurality of induction coils; the soaking section is provided with a plurality of electric radiation tubes; the cooling section comprises a cooling unit; the balancing section is provided with a plurality of electric radiation tubes; the outlet section comprises an adjustment unit, a heat tensioning roller chamber and a furnace nose connected in sequence; and a heating device is arranged in the adjustment unit. Compared with the prior art, the utility model has the characteristics of low cost and good effect.

Description

Technical Field

[0001] The utility model relates to a galvanizing device, in particular to a galvanizing heating device for performing recrystallization annealing on low-carbon steel rolled by a rolling mill with a low compression ratio. Background Art

[0002] Low compression ratio rolling has the advantages of reducing rolling energy consumption, reducing production costs, and improving production efficiency. However, rolling with a low compression ratio of 20-50% has less deformation energy storage and low recrystallization driving force. Therefore, recrystallization annealing must be completed in the galvanizing furnace to ensure that the strip performance meets the use requirements. The existing recrystallization annealing is time-consuming and costly, which makes it easier to achieve cost reduction benefits with low compression ratio rolling.

[0003] Therefore, there is an urgent need for a galvanizing heating device for recrystallization annealing of low-carbon steel rolled at a low reduction ratio by a rolling mill. Utility Model Content

[0004] The technical task of the utility model is to provide a low compression ratio hot-rolled steel continuous galvanizing heating device in view of the deficiencies of the above prior art.

[0005] The utility model solves the technical problem by means of a technical solution: comprising a heating section, a soaking section, a cooling section, a balancing section and an outlet section connected in sequence; wherein the heating section is provided with a plurality of induction coils; the soaking section is provided with a plurality of electric radiation tubes; the cooling section comprises a cooling unit; the balancing section is provided with a plurality of electric radiation tubes; the outlet section comprises an adjustment unit, a heat tensioning roller chamber and a furnace nose connected in sequence; and a heating device is arranged inside the adjustment unit.

[0006] Furthermore, the induction coil is composed of a plurality of induction bodies arranged vertically in series.

[0007] Furthermore, the above-mentioned induction bodies all adopt longitudinal magnetic heating method.

[0008] Furthermore, the cooling unit includes a cooling fan and a protective gas circulation device.

[0009] Furthermore, the heating device is a plurality of electric heating tubes.

[0010] Furthermore, an atmosphere isolation mechanism is provided in the adjustment unit.

[0011] Furthermore, a zinc ash isolation baffle, a nitrogen protective gas heating device and an exhaust system are arranged inside the furnace nose.

[0012] Compared with the prior art, the utility model has the following outstanding beneficial effects:

[0013] 1. Induction heating and electric radiation tube heating are used to achieve recrystallization annealing. Compared with open flame heating and single radiation tube heating equipment, the investment cost is small, and it is safe, environmentally friendly and has low production cost;

[0014] 2. Improve the quality of galvanized products and prevent zinc ash from settling in the furnace nose and falling and adhering to the surface of the strip to form needle-shaped leakage plating;

[0015] 3. Reduce the zinc ash content by improving the outlet section, effectively preventing the zinc ash from falling back into the plating solution to form scum. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the utility model.

[0017] Figure 2 It is a schematic diagram of the structure of the outlet section of the utility model. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments of the specification. In the following, only certain exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the embodiments of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0019] In the following embodiments, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present utility model application can be understood according to the specific circumstances.

[0020] In order to better describe, the front and back are set based on the direction of the strip steel, the coming direction is the front, and the going direction is the back; that is, Figure 1The left direction is the front, and the opposite direction is the back. It should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", "end", "side" and the like indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the utility model application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the embodiments of the utility model application.

[0021] like Figure 1 , 2 As shown, the utility model comprises a heating section 1, a heat equalizing section 2, a cooling section 3, a balancing section 4 and an outlet section 5 which are connected in sequence.

[0022] The heating section 1 is provided with a plurality of induction coils, through which the strip steel 8 is heated to 720° C. to 730° C. in 3-5 seconds of the heating section 1. In the embodiment of the utility model, the induction coils are arranged in series vertically with a plurality of induction bodies, and each induction body adopts a longitudinal magnetic heating method.

[0023] The soaking section 2 is provided with a plurality of electric radiation tubes, and the electric radiation tubes are used for heating to ensure that the strip temperature is maintained at 720° C. to 730° C. for ≥10 seconds, and the time at ≥630° C. is ≥21 seconds.

[0024] Since the heating section 1 adopts the induction coil heating method, if the heat preservation is not performed, the strip steel after induction heating will quickly cool down by 20-30°C within 1S-2S. Therefore, it is necessary to compensate the energy loss of the strip steel by the power of the electric radiation tube of the soaking section 2. In the embodiment of the utility model, the electric radiation tube of the soaking section 2 cooperates with the induction coil of the heating section 1 to achieve: the strip steel is first heated to above 720°C, and is kept above this temperature for more than 10S to ensure that the strip steel has sufficient energy for recrystallization nucleation, and then the strip steel temperature in the soaking section 2 is ≥630°C for ≥21s; it is ensured that the strip steel can be fully recrystallized, and at the same time, the temperature difference between the surface temperature of the strip steel and the core is reduced, so that the cross-sectional temperature of the strip steel is consistent, which is conducive to more uniform galvanizing in the zinc pot 6 later.

[0025] The cooling section 3 is arranged after the soaking section 2, and includes a cooling unit, which includes a plurality of cooling units, and the cooling unit includes a cooling fan and a protective gas circulation device. When in use, the cooling fan is used to spray the circulating cooled protective gas onto the steel strip, and the steel strip is cooled from the soaking temperature to the temperature of the zinc pot 6. This is a common cooling method in the art, and the specific structure is not repeated here.

[0026] The equalizing section 4 is arranged after the cooling section 3, and includes a plurality of electric radiation tubes, which are used to equalize the strip steel after cooling in the cooling section. The outlet temperature of the equalizing section 4 is 550-600℃. The strip steel ensures that the equalizing time is ≥6s to ensure that the transverse temperature of the thick-gauge strip steel is uniform after leaving the cooling section; at the same time, the thin-gauge products are supplemented with heating to ensure their temperature entering the zinc pot 6. In this embodiment, the equalizing section 4 is heated by electric radiation tubes to ensure that the transverse temperature of the thick-gauge strip steel is uniform after leaving the cooling section; at the same time, the thin-gauge products are supplemented with heating to ensure their temperature entering the zinc pot 6. If the equalizing section 4 is not provided, the zinc ash in the furnace nose is disturbed by the cooling section fan, sucked into the furnace and falls on the surface of the steel plate, causing zinc leakage.

[0027] In order to ensure the fluidity of the plating liquid metal, the temperature in the zinc pot 6 for aluminum zinc plating or zinc plating is generally controlled at about 600°C, which is far higher than the melting point of metal zinc (419°C). Zinc vapor is inevitably generated during the production process. Zinc vapor moves upward with the air flow and condenses into "zinc ash" in the outlet section 5 at a lower ambient temperature. The zinc ash is deposited in the furnace nose 53, falls and adheres to the surface of the strip to form needle-shaped leakage plating, or falls back into the plating liquid to form scum, and contacts with the strip to form leakage plating, which seriously affects the product quality. Therefore, the outlet section 5 includes an adjustment unit 51, a hot tension roller chamber 52 and a furnace nose 53 connected in sequence. After the outlet section 5, the temperature of the strip entering the zinc pot 6 is 550°C-590°C.

[0028] The adjustment unit 51 is a narrow passage lined with refractory material, which is provided with an atmosphere isolation mechanism and a heating device. The atmosphere isolation mechanism is used to isolate the atmosphere flow between the front and rear furnace sections, and prevent the atmosphere containing zinc vapor from flowing into the heating device. The atmosphere isolation mechanism can be any structure that can isolate the atmosphere flow between the front and rear furnace sections.

[0029] The heating device is provided with a plurality of electric heating tubes to ensure that the furnace gas temperature in the region is always above the condensation temperature of zinc vapor, that is, greater than 470° C., to ensure that the zinc vapor will not condense into zinc ash in the adjustment unit 51 .

[0030] In the optimization scheme, the furnace nose 53 is improved, and a zinc ash isolation baffle, a nitrogen protective gas heating device and an exhaust system are set inside the furnace nose 53. The zinc ash isolation baffle is used to prevent zinc ash from contaminating the heat tension chamber and the cooling section heat exchanger. The nitrogen protective gas heating device adds inert gas N2 as a protective gas to accelerate the reflux of the zinc vapor-containing atmosphere and avoid the reaction of zinc vapor; the exhaust system extracts zinc vapor from the furnace nose 53 to reduce the zinc ash content.

[0031] When the utility model is used, the raw material coil is pickled and then rolled by a rolling mill at a low compression ratio of 20-50%. The rolled strip steel 8 passes through the heating section 1, the soaking section 2, the cooling section 3, the equalization section 4, and the outlet section 5 in the heating process in the furnace in sequence, and is recrystallized and annealed. Finally, it enters the zinc pot 6 for galvanizing, and is cooled in the cooling section 7 after galvanizing, so as to realize the low-cost production of color-coated substrates with a thickness of 0.4-0.8mm.

[0032] It should be noted that matters not described in detail in this embodiment are well-known technologies in the art.

[0033] The above description is only for the purpose of describing the present invention in detail for the specific implementation purpose of the present invention. For those skilled in the art, various obvious changes made to the present invention without departing from the spirit and scope of the present invention are within the protection scope of the present invention.

Claims

1. A low compression ratio hot-rolled steel continuous galvanizing heating device, characterized in that: It comprises a heating section, a soaking section, a cooling section, a balancing section and an outlet section connected in sequence; wherein the heating section is provided with a plurality of induction coils; the soaking section is provided with a plurality of electric radiation tubes; the cooling section comprises a cooling unit; the balancing section is provided with a plurality of electric radiation tubes; the outlet section comprises an adjustment unit, a heat tensioning roller chamber and a furnace nose connected in sequence; and a heating device is provided in the adjustment unit.

2. The low compression ratio hot-rolled steel continuous galvanizing heating device according to claim 1 is characterized in that: The induction coil is composed of a plurality of induction bodies arranged vertically in series.

3. The low compression ratio hot-rolled steel continuous galvanizing heating device according to claim 2 is characterized in that: The induction bodies all adopt longitudinal magnetic heating method.

4. The low compression ratio hot-rolled steel continuous galvanizing heating device according to claim 1 is characterized in that: The cooling unit includes a cooling fan and a protective gas circulation device.

5. The low compression ratio hot-rolled steel continuous galvanizing heating device according to claim 1 is characterized in that: The heating device is a plurality of electric heating tubes.

6. The low compression ratio hot-rolled steel continuous galvanizing heating device according to claim 1, characterized in that: An atmosphere isolation mechanism is provided in the adjustment unit.

7. The low compression ratio hot-rolled steel continuous galvanizing heating device according to claim 1, characterized in that: A zinc ash isolation baffle, a nitrogen protective gas heating device and an exhaust system are arranged inside the furnace nose.

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