CN115106376A

CN115106376A - Hot-rolled H-shaped steel galvanizing production line and method thereof

Info

Publication number: CN115106376A
Application number: CN202210655354.4A
Authority: CN
Inventors: 王艳丽; 安卫春
Original assignee: Hebei Xinda Iron and Steel Group Co Ltd
Current assignee: Hebei Xinda Iron and Steel Group Co Ltd
Priority date: 2022-06-10
Filing date: 2022-06-10
Publication date: 2022-09-27

Abstract

The invention discloses a hot-rolled H-shaped steel continuous hot galvanizing production line and a method thereof, belonging to the field of hot galvanizing of H-shaped steel, and comprising a conveying part, and a high-pressure water dephosphorization device, a surface impurity and moisture removal device, a galvanizing device, a cooling device, a straightening and finishing system and a surface chemical passivation system which are sequentially arranged on the conveying part from front to back; the hot-rolled H-shaped steel is conveyed by the conveying part, subjected to dephosphorization and surface impurity water removal, conveyed to a galvanizing device, sprayed with a zinc layer on the surface, and subjected to cooling, straightening and chemical passivation to complete continuous hot galvanizing. The invention has the beneficial effects that: the hot-rolled H-shaped steel is subjected to continuous hot galvanizing after being finally rolled, and the subsequent galvanizing process treatment is performed by utilizing the sufficient heat of the hot-rolled H-shaped steel with high temperature of above 850 ℃ after being finally rolled without energy consumption heating, so that the problem of high energy consumption of the hot-rolled H-shaped steel is solved, the continuous production is realized, the automation degree and the yield are improved, and the galvanizing production cost of the hot-rolled H-shaped steel is greatly reduced.

Description

Hot-rolled H-shaped steel galvanizing production line and method thereof

Technical Field

The invention relates to the field of hot galvanizing of H-shaped steel, in particular to a hot rolling H-shaped steel galvanizing production line and a hot rolling H-shaped steel galvanizing method.

Background

The existing hot-rolled H-shaped steel hot galvanizing process is that a hot-rolled H-shaped steel finished product cut into sections is purchased by a galvanizing processing factory at the downstream of a hot-rolled H-shaped steel factory, and the hot-rolled H-shaped steel finished product is required to be subjected to fussy acid washing, alkali washing, rinsing with clear water and hydrogen reduction atmosphere heating, then is soaked in a zinc pool for galvanizing, and then is subjected to fussy post-galvanizing passivation and other procedures to complete the production of the hot-rolled H-shaped steel product. It has the following disadvantages: (1) the comprehensive energy consumption is high, energy is consumed by heating with hydrogen, and complicated processes such as acid washing, alkali washing, hot water rinsing and the like are needed, so that the realization of carbon reduction and emission reduction in society is not facilitated; (2) discontinuous production, complex process, low yield, severe working environment and no contribution to physical and psychological health of workers; (3) the produced hot-rolled H-shaped steel has high cost; (4) due to the special shape of the hot-rolled H-shaped steel and the high strength of the steel for building structures, the hot-rolled H-shaped steel cannot be immersed into a galvanizing bath for continuous galvanizing, and meanwhile, a galvanizing process cannot be realized due to the storage of zinc liquid in the H-shaped steel structure, so that the hot-rolled H-shaped steel cannot be subjected to continuous hot galvanizing.

In view of the above, the present inventors have made extensive studies to meet this need.

Disclosure of Invention

In order to solve the problems of high comprehensive energy consumption, low yield, severe working environment, high production cost and the like of a hot-rolled H-shaped steel hot galvanizing process in the prior art, the invention provides a hot-rolled H-shaped steel continuous hot galvanizing production line which comprises a conveying part, and a high-pressure water dephosphorization device, a surface impurity and moisture removal device, a galvanizing device, a cooling device, a straightening and finishing system and a surface chemical passivation system which are sequentially arranged on the conveying part from front to back.

Preferably, the high-pressure water dephosphorization device comprises a high-pressure medium spray pipe for spraying water on the surface of the hot-rolled H-shaped steel, the high-pressure medium spray pipe is an H-shaped pipe surrounding the outer side surface of the hot-rolled H-shaped steel, and a high-pressure medium spray nozzle is formed on one side, close to the surface of the hot-rolled H-shaped steel, of the high-pressure medium spray pipe.

Preferably, the surface impurity moisture removing device comprises a flushing pipe used for flushing the surface of the hot-rolled H-shaped steel and a high-pressure purging pipe used for assisting in cleaning, the flushing pipe and the high-pressure purging pipe are sleeved on the hot-rolled H-shaped steel along the length direction of the hot-rolled H-shaped steel, a flushing nozzle is formed on one side, close to the surface of the hot-rolled H-shaped steel, of the flushing pipe, and a high-pressure purging nozzle is formed on one side, close to the surface of the hot-rolled H-shaped steel, of the high-pressure purging pipe.

Preferably, the galvanizing device comprises a long-strip groove-shaped galvanizing kettle, a roller way assembly which is arranged in the length direction of the galvanizing kettle and used for conveying the hot-rolled H-shaped steel, and a zinc liquid spraying pipe assembly used for spraying zinc liquid in the galvanizing kettle on the surface of the hot-rolled H-shaped steel, wherein the galvanizing kettle is arranged right below the zinc liquid spraying pipe assembly.

Preferably, the cooling device comprises an air cooling device and a water cooling device, and the air cooling device comprises a cooling air box arranged on the conveying part; the cooling air box is of a hollow structure, air holes for feeding cold air are uniformly distributed on the inner walls of two sides of the cooling air box, and the outer wall of the cooling air box is connected with a cold air system for conveying cold air to the cooling air box.

Preferably, the water cooling device comprises a water cooling assembly arranged on the conveying part; the water cooling assembly is arranged at the periphery of the hot rolling H-shaped steel and is uniformly distributed with water spray nozzles on one side close to the hot rolling H-shaped steel, and the conveying part is provided with gas sealing assemblies at the positions of two ends of the water cooling assembly.

Preferably, the straightening and finishing system comprises a side-bending straightening roller machine arranged in the length direction of the hot-rolled H-shaped steel and used for straightening the side-bending of the hot-rolled H-shaped steel, a horizontal straightening machine used for straightening a web plate of the hot-rolled H-shaped steel, a finishing and rolling machine used for flattening the surface unevenness of the hot-rolled H-shaped steel and a edging and rolling machine used for straightening the upper edge and the lower edge of the hot-rolled H-shaped steel. Preferably, the surface chemical passivation system includes chemical passivation device, and chemical passivation device includes passivation solution accumulator and sets up the cloth liquid roller subassembly directly over the passivation solution accumulator, and it is provided with the first air seal pipe that is used for carrying out the air seal around the hot rolling H shaped steel to lie in cloth liquid roller subassembly both ends position department on the hot rolling H shaped steel length direction, and first air seal pipe box is established on hot rolling H shaped steel and is located passivation solution accumulator top position department.

The invention also provides a continuous hot galvanizing method for the hot-rolled H-shaped steel, which comprises the following steps:

step one, hot-rolled H-shaped steel with the temperature of 850-950 ℃ enters a high-pressure water dephosphorization device for dephosphorization under the conveying of a conveying part, and the water pressure of high-pressure water is 15-20 Mpa; removing impurity moisture on the surface by a surface impurity moisture removing device, and controlling the temperature of the hot-rolled H-shaped steel to be 500-560 ℃;

conveying the hot-rolled H-shaped steel with the impurity and water removed from the surface to a galvanizing device, and spraying a zinc layer on the surface of the hot-rolled H-shaped steel;

step three, cooling the galvanized hot-rolled H-shaped steel by a cooling device to reduce the surface temperature of the hot-rolled H-shaped steel to be below 80 ℃;

and step four, straightening the cooled hot-rolled H-shaped steel by a straightening and finishing system, flattening slag particles or other uneven point-shaped objects on the surface of the hot-rolled H-shaped steel, and chemically passivating by a surface chemical passivation system to form a passivation film on the surface of the hot-rolled H-shaped steel.

The technical scheme of the invention has the following beneficial effects:

(1) the hot-rolled H-shaped steel is subjected to continuous hot galvanizing after being finally rolled, and the subsequent galvanizing process treatment is carried out by utilizing sufficient heat of high temperature of over 850 ℃ after the hot-rolled H-shaped steel is finally rolled without energy consumption heating, so that the problem of high energy consumption of the hot-rolled H-shaped steel is solved, the continuous production is realized, the automation degree and the yield are improved, and the galvanizing production cost of the hot-rolled H-shaped steel is greatly reduced.

(2) The zinc plating in the non-immersed zinc bath is realized by using a zinc liquid lifting pump and a spraying device, the thickness of a zinc coating is controlled by using an air knife, and the problem of liquid accumulation on the H-shaped section is solved by using an air seal technology.

(3) The long-strip groove-shaped galvanized pot, the roller way assembly and the zinc liquid spraying pipe assembly are matched, the H-shaped steel passes through the upper part of the long-strip groove-shaped galvanized pot under the driving of the roller way assembly, and a zinc layer is sprayed on the surface of the H-shaped steel through the zinc liquid spraying pipe assembly, so that the bottleneck technical problem of 'continuous rolling and continuous plating' of the hot-rolled H-shaped steel is solved, the yield of the hot-rolled H-shaped steel is greatly improved, and the energy consumption and the emission are reduced.

(4) And (3) adopting a high-pressure low-flow acute-angle air knife, enabling compressed air to pass through a flat nozzle in the air knife to form uniform flat air flow, and blowing molten zinc on the surface of the H-shaped steel to a specified zinc layer thickness.

(5) And heating the zinc solution by adopting an electromagnetic induction heater, and keeping the temperature of the hot galvanizing melt within a set range so as to meet the temperature requirement of the galvanizing process.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.

FIG. 1 is a schematic view of a hot-rolled H-section galvanizing line according to the present invention;

FIG. 2 is a flow chart of the preferred hot-rolled H-section galvanizing process of the present invention;

FIG. 3 is a schematic side view of the preferred hot rolled H-shaped steel high pressure water phosphorus removal device of the present invention;

FIG. 4 is a schematic top view of the hot rolled H-shaped steel high pressure water phosphorus removal device of the present invention;

FIG. 5 is a structural view of a preferred H-shaped high-pressure medium nozzle of the present invention;

FIG. 6 is a schematic diagram of a preferred high pressure water circulation system of the present invention;

FIG. 7 is a schematic side view of the impurity moisture removing apparatus according to the present invention;

FIG. 8 is a schematic top view of the preferred impurity and moisture removing device of the present invention;

FIG. 9 is a schematic diagram of a preferred annular tube structure of the present invention;

FIG. 10 is a schematic view of a preferred square tube structure of the present invention;

FIG. 11 is a schematic side view of the preferred galvanizing apparatus of the present invention;

FIG. 12 is a schematic top view of the preferred galvanizing apparatus of the present invention;

FIG. 13 is a schematic top view of a preferred air knife structure of the present invention;

FIG. 14 is a schematic side view of a preferred air knife structure of the present invention;

FIG. 15 is a schematic view of the air cooling device for hot-rolled H-section steel according to the present invention;

FIG. 16 is a schematic longitudinal sectional view of a preferred hot-rolled H-shaped steel cooling windbox of the present invention;

FIG. 17 is a schematic view of a water cooling apparatus for hot-rolled H-section steel according to the present invention;

FIG. 18 is a schematic longitudinal sectional view of a cylindrical water cooler for hot-rolled H-section steel according to the present invention;

FIG. 19 is a schematic top view of the preferred galvanized H-beam straightening and finishing system of the present invention;

FIG. 20 is a schematic view showing the construction of a horizontal leveler for galvanized H-beam steel according to the preferred embodiment of the present invention;

FIG. 21 is a schematic view of the preferred combination of the skin-pass mill and the edger mill of the present invention;

FIG. 22 is a schematic side view of the polishing and rolling machine for galvanized H-section steel according to the preferred embodiment of the present invention;

FIG. 23 is a side view of the preferred galvanized H-beam edger of the present invention;

FIG. 24 is a schematic structural view of a chemical passivation system for the surface of a preferred hot rolled H-section steel according to the present invention;

FIG. 25 is a schematic view of a preferred liquid distribution roller assembly of the present invention;

FIG. 26 is a schematic view of a drying system according to the present invention;

FIG. 27 is a cross-sectional view of a square box of the hot air oven of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

As shown in fig. 1-4, the hot-rolled H-section steel continuous hot galvanizing production line comprises a conveying part 1, and a high-pressure water dephosphorization device 2, a surface impurity moisture removal device 3, a galvanizing device 4, a cooling device 5, a straightening and finishing system 6 and a surface chemical passivation system 7 which are sequentially arranged on the conveying part 1 from front to back. The conveying component 1 comprises roller way supports 11, a conveying motor 12 and conveying rollers 13, wherein the roller way supports are arranged along the length direction of the hot-rolled H-shaped steel 100, a central shaft at one end of each conveying roller 13 is installed on a rotating shaft of the conveying motor 12, and two ends of the central shaft are installed on the roller way supports 11 through bearing seats 14. The hot-rolled H-shaped steel is placed on a conveying roller, the conveying roller is driven by a motor to rotate, the hot-rolled H-shaped steel moves along the length direction and sequentially passes through a high-pressure water dephosphorization device 2, a surface impurity and moisture removal device 3, a galvanizing device 4, a cooling device 5, a straightening finishing system 6 and a surface chemical passivation system 7, and continuous hot galvanizing operation is completed.

The high-pressure water dephosphorization device 2 comprises a high-pressure medium spray pipe 21 for spraying water on the surface of the hot-rolled H-shaped steel, the high-pressure medium spray pipe 21 is an H-shaped pipe surrounding the outer side surface of the hot-rolled H-shaped steel 100, and a high-pressure medium spray nozzle 211 is formed on one side, close to the surface of the hot-rolled H-shaped steel 100, of the high-pressure medium spray pipe 21. According to the shape design H type high pressure medium spray tube of hot rolling H shaped steel, make the hydroenergy of nozzle blowout on the spray tube spout each position on hot rolling H shaped steel surface, clear away hot rolling H shaped steel surface because of high temperature oxidation's attached oxide scale, effectively ensured the hot-galvanize quality effect of next procedure, and the iron-zinc alloy basic unit that forms is effectual, has avoided the zinc-plating insecure, the emergence of the problem that drops.

The high-pressure medium nozzles 211 are inclined towards the inlet direction of the hot-rolled H-shaped steel 100 on the high-pressure medium spray pipe 21, the included angle between the water spraying direction of the high-pressure medium nozzles 211 and the vertical direction is 10-30 degrees, the preferred included angle is 15 degrees, and in the design process, the adjustment of the water spraying direction of the high-pressure medium nozzles 211 has a large influence on the high-pressure water striking force, and when the included angle is 10-30 degrees and the preferred included angle is 15 degrees, the high-pressure water striking force is high in strength, and the cleaning effect is good.

Three high-pressure medium nozzles 21 are provided in the longitudinal direction of the conveying member 1. Three high-pressure medium spray pipes are arranged to clean the surface of the hot-rolled H-shaped steel, so that the effect of removing the iron scale attached to the surface of the hot-rolled H-shaped steel due to high-temperature oxidation is more thorough.

As shown in FIG. 5, the high pressure medium spray pipes 21 include side spray pipes 212 disposed at both outer sides of the hot rolled H-section steel, upper spray pipes 213 disposed at upper and lower positions of the hot rolled H-section steel, and inner spray pipes 214 disposed at upper and lower inner positions of the hot rolled H-section steel, and the side spray pipes 212, the upper spray pipes 213, and the inner spray pipes 214 are connected in series to form an H-shaped closed loop and surround the surface of the hot rolled H-section steel. The high-pressure water sprayed from the upper nozzle of the inner spray pipe can remove phosphorus from the complex section in the hot-rolled H-shaped steel, and the problem that the existing steel billet phosphorus removal equipment cannot remove phosphorus from the complex section of the hot-rolled H-shaped steel is solved. The high-pressure medium spray pipe 21 and the spray nozzle 211 are both stainless steel pipes, preferably thick-wall stainless steel pipes, and bear the pressure of at least 20 MPa. The middle position of two sides of the high-pressure medium spray pipe 21 is provided with a high-pressure medium inlet pipe 215, and the high-pressure medium spray pipe inlet pipe 215 is connected with the high-pressure water circulating system 22.

As shown in fig. 6, the high-pressure water circulation system 22 includes a trench 221, a cyclone well 222, a sedimentation tank 223, a first filter 224, a cooling tower 225, a cooling tower cooling water tank 226, a low-pressure water pump 227, a second filter 228, an axial compressor 229, an accumulator 230, and a control valve 231 in this order along the water flow direction, and the control valve 231 is located at the position of the high-pressure medium inlet pipe 215. A phosphorus removal cover 23 is arranged above the hot-rolled H-shaped steel 100, and the high-pressure medium spray pipe 21 is positioned below the phosphorus removal cover 23. The phosphorus removal cover 23 is provided with a splash-proof curtain 232 close to the input end of the conveying component 1. The splash-proof curtain can effectively prevent the high-pressure water sprayed out of the high-pressure medium spray pipe from splashing, and the production environment is improved.

The hot-rolled H-shaped steel is placed on the conveying roller, the conveying roller is driven by the motor to rotate, the hot-rolled H-shaped steel moves along the length direction, and in the process of passing through the high-pressure medium spray pipe, high-pressure water sprayed by the high-pressure medium spray pipe removes iron scales attached to the surface, so that preparation is made for a subsequent galvanizing procedure.

As shown in fig. 7 to 8, the surface impurity moisture removing device 3 includes a flushing pipe 31 for flushing the surface of the hot-rolled H-section steel 100 and a high-pressure purging pipe 32 for boosting cleaning, the flushing pipe 31 and the high-pressure purging pipe 32 are sleeved on the hot-rolled H-section steel 100 along the length direction of the hot-rolled H-section steel 100, a flushing nozzle 311 is formed on the flushing pipe 31 near the surface of the hot-rolled H-section steel 100, and a high-pressure purging nozzle 321 is formed on the high-pressure purging pipe 32 near the surface of the hot-rolled H-section steel. The flushing pipe is matched with the high-pressure blowing pipe, firstly, the flushing nozzle 311 on the flushing pipe adds clean water to the surface of the hot-rolled H-shaped steel 100 to clean the surface of the hot-rolled H-shaped steel, and then, high-pressure air blown by the high-pressure blowing nozzle 321 of the high-pressure blowing pipe 32 is used for blowing and stirring the clean water on the surface of the hot-rolled H-shaped steel 100, so that the effect of cleaning the surface of the steel by clean water turbulence is realized. The left side and the right side of the flushing pipe 31 are provided with a first interface pipe 312, the flushing pipe 31 is one of a circular ring pipe, a square pipe or an H-shaped pipe, and the inner side surface of the flushing pipe is provided with a plurality of flushing nozzles 311. The H-shaped pipe has the best effect, and the circular ring pipe and the square pipe can achieve the expected washing effect. The structure of the H-shaped pipe can be referred to the structure of the high-pressure medium spray pipe in FIG. 5, and the structures of the circular ring-shaped pipe and the square pipe are shown in FIGS. 9-10.

The hot-rolled H-shaped steel 100 is alternately sleeved with 2-4 groups of flushing pipes 31 and high-pressure purging pipes 32 in the length direction. Here, when the flushing pipes and the high-pressure purge pipes are provided, 1 flushing pipe and 1 high-pressure purge pipe may be set, 2 flushing pipes and 1 high-pressure purge pipe may be set, and 1 flushing pipe and 1 high-pressure purge pipe may be set, and 2 sets are provided in total. The high-pressure purging pipe is arranged behind the flushing pipe, and the high-pressure purging pipe and the flushing pipe are matched to mainly enable clean water on the surface of the hot-rolled H-shaped steel to form turbulent flow, so that a better cleaning effect is achieved. Wherein, the last high-pressure air sweeps, has ensured simultaneously that hot rolling H shaped steel is dry clean before entering galvanizing rig, accords with the galvanizing requirement. And two high-pressure air blowing devices can be arranged, so that accidents are avoided, and the safety is high.

Clean water enters the flushing pipe through the first interface tube and then is sprayed out from the first nozzle, and cleaning is achieved. The clean water can be clear water or alkali liquor, the clean water can be determined according to whether the oil stain (mineral oil) on the surface of the hot-rolled H-shaped steel exceeds the standard, if the oil stain exceeds the standard, the alkali liquor can be added into the front flushing pipe for cleaning, the effect is improved, and then the cleaning is carried out by using clear water. In the design, the cleaning quality and cost are comprehensively considered, the alkali liquor is added into the flushing pipe close to the front part, and the clean water is added into the flushing pipe at the rear part, so that the process flexibility is higher. The selection of the alkali washing process mainly aims at the condition that mineral oil exceeds the standard, such as the condition that lubricating oil is attached to the surface of hot-rolled H-shaped steel of a rolling mill which is just assembled on a production line, and the lubricating oil can be washed by alkali and then rinsed by clear water, so that the cleaning is thorough. In addition, NaOH solution is preferably adopted as the cleaning solution in the alkali washing process, and the concentration range of the cleaning solution is 2-5%. The water spraying pressure of the low-pressure cleaning water and the wind pressure of the high-pressure wind can be set according to the requirement, and the water pressure of the low-pressure cleaning water is preferably 0.2 MPa; the high pressure wind pressure is 0.8 MPa.

The high-pressure purge pipe 32 is one of a circular ring pipe, a square pipe, or an H-shaped pipe, and the inner side surface thereof is provided with a plurality of high-pressure purge nozzles 321. The high-pressure purge pipe 32 is preferably an H-shaped pipe, and has the best purge effect because the distance between the high-pressure purge pipe and each surface of the hot-rolled H-shaped steel is not large. The structure of the H-shaped pipe can be referred to the structure of the high-pressure medium spray pipe 21 in fig. 5, and the structure of the circular ring-shaped pipe and the square pipe can be referred to the structure of the flushing pipe 31 in fig. 9-10. The left side and the right side of the high-pressure purging pipe 32 are provided with second interface pipes 322, the included angle between the purging direction of the high-pressure purging nozzle 311 and the vertical direction is 30-45 degrees, and the preferred included angle is 35 degrees.

A cleaning cover 33 is arranged above the hot-rolled H-shaped steel 100, and the high-pressure purging pipe 32 and the flushing pipe 31 are positioned below the cleaning cover 33. A circulating water trench (not shown in the figure) is arranged below the conveying component 1. Circulating water is used in the rolling process and the hot rolling H-shaped steel dephosphorization process after rolling, and the salt content in water is increased due to water evaporation, so that the galvanizing effect is influenced. Clean water is added into the impurity and moisture removing device on the surface of the hot-rolled H-shaped steel, and the water falls into a circulating water trench after being cleaned and is communicated with the trench in the hot-rolled H-shaped steel dephosphorization procedure, so that not only can fresh water be supplemented to a circulating water system in the dephosphorization procedure, but also the surface of the hot-rolled H-shaped steel can be cleaned.

As shown in fig. 11 to 12, the galvanizing apparatus 4 includes a strip-shaped channel-shaped galvanizing pot 41 disposed just below the galvanizing pot, a roller assembly 43 arranged in the lengthwise direction of the galvanizing pot for conveying the hot-rolled H-section steel, and a molten zinc spray pipe assembly 42 for spraying molten zinc in the galvanizing pot onto the surface of the hot-rolled H-section steel 100. The zinc liquid spray pipe assembly comprises a zinc liquid axial-flow pump 421, a hydraulic motor 422, a zinc liquid spray pipe 423 and a zinc liquid spray nozzle 424, the zinc liquid axial-flow pump 421 is arranged in the galvanizing pot 41, the zinc liquid axial-flow pump and the hydraulic motor, the hydraulic motor 422 and the zinc liquid spray pipe 423 are connected through pipelines, and the zinc liquid spray nozzle is arranged on the zinc liquid spray pipe; the zinc liquid spray pipe 423 is sleeved on the periphery of the hot-rolled H-shaped steel, and a plurality of zinc liquid spray nozzles are arranged on one side of the zinc liquid spray pipe, which is close to the surface of the hot-rolled H-shaped steel 100. The zinc liquid spray pipe is a square pipe or an H-shaped pipe, and the structure can be shown in figures 5, 9 and 10.

An electromagnetic induction heater 411 is arranged in the galvanizing pot 41. And heating the zinc solution by adopting an electromagnetic induction heater, and keeping the temperature of the hot galvanizing melt within a set range so as to meet the temperature requirement of the galvanizing process. An air knife structure 44 for controlling the thickness of the molten zinc on the surface of the hot-rolled H-shaped steel 100 is arranged close to the output end of the roller way assembly 43. And (3) adopting a high-pressure low-flow acute-angle air knife, enabling compressed air to pass through a flat nozzle in the air knife to form uniform flat air flow, and blowing molten zinc on the surface of the H-shaped steel to a specified zinc layer thickness.

The roller way assembly 43 comprises a plurality of roller ways 431 uniformly distributed along the length direction of the galvanizing kettle, and each roller way 431 is provided with a roller way slag scraper 432 for preventing zinc slag from being attached to the roller way 431. The roller way slag scraper adopts a cylinder to drive the roller way slag scraper to stretch, so that zinc slag hung on the roller way can be effectively removed.

The wall of the galvanized pot 41 sequentially comprises a high-temperature-resistant coating layer 412, a fire-resistant insulating layer 413 and a zinc pot outer shell layer 414 from inside to outside. The outer shell 414 of the zinc pot is made of 15-30mm steel plate, preferably 20mm steel plate. The fire-resistant insulating layer 413 is built into an inverted arch shape, so that the fire-resistant insulating layer can be prevented from floating on the surface of the zinc liquid. The high-temperature resistant coating layer 412 is sprayed on the inner part, so that the corrosion of zinc liquid to the refractory of the zinc pot can be reduced, and the high-temperature coating layer is preferably ceramic. The zinc pot can move transversely and is divided into an online zinc pot and a zinc preparation pot. The on-line zinc pot and the preparation zinc pot both move transversely through a rail moving vehicle below the zinc pot, so that alternate use between the on-line zinc pot and the preparation zinc pot is realized, and meanwhile, a zinc pot hydraulic lifting device is arranged, so that lifting of zinc pot liquid is realized. The rated power of the electromagnetic induction heater of the zinc pot is 3 multiplied by 400 KW.

As shown in fig. 13 and 14, the air knife structure 44 includes a fixed frame 441, a gas supply assembly 442, and a plurality of air knife assemblies 443 disposed on the surface of the hot-rolled H-section steel 100; an air knife assembly 443 is mounted on the fixed frame 441, the air knife assembly includes an air knife 444, and an air knife nozzle 445 faces the surface of the hot-rolled H-shaped steel 100; a passage 446 for passage of gas is formed in the gas knife with one end communicating with the gas knife nozzle and the other end communicating with the gas supply assembly. The air knife component is arranged on the surface of the H-shaped steel, compressed air passes through an air knife nozzle in the air knife component to form uniform flat air flow, the zinc liquid on the surface of the H-shaped steel is strickled off, the required thickness of a zinc layer is achieved, and the uniformity of the thickness of the zinc layer on the surface of the H-shaped steel is improved.

The air knife assembly 443 is arranged on the outer side of the left flange of the H-shaped steel, the outer side of the right flange, right above the web, right below the web, on the inner side of the left flange above the web, on the inner side of the right flange above the web, on the inner side of the left flange below the web and on the inner side of the right flange below the web. Aiming at the complex section shape of the H-shaped steel, air knife assemblies in different directions are respectively arranged on the surfaces of different positions of the H-shaped steel, and the surfaces of different positions of the H-shaped steel are respectively subjected to blowing treatment, so that a universal angle blowing air knife structure is formed, the thickness precision of a zinc layer of the continuously galvanized H-shaped steel is effectively controlled, and the quality of a continuous hot-galvanized finished product of the hot-rolled H-shaped steel is guaranteed.

The air supply assembly comprises 3 sets of air supply systems, wherein the air knife assemblies are located right above a 100 web of hot-rolled H-shaped steel, on the inner side of a left flange above the web and on the inner side of a right flange above the web and share 1 set of air supply system, the air knife assemblies are located right below the 100 web of hot-rolled H-shaped steel, on the inner side of a left flange below the web and on the inner side of a right flange below the web and share 1 set of air supply system, and the air knife assemblies are located on the outer side of the left flange and on the outer side of the right flange of hot-rolled H-shaped steel. According to the needs of the surface of the H-shaped steel at different positions for the intensity of purging the zinc liquid, 3 sets of gas supply systems are arranged, the gas supply intensity is adjusted as required, and the accurate control of the purging effect on the surface of the H-shaped steel at different positions is realized.

The air supply system comprises an air supply fan and a control device, the control device controls the air supply of the air supply fan, the air supply fan is a single-stage high-speed centrifugal blower, the rated flow of the air supply fan is 8000Nm3/h, the working air pressure is 1.8bar, the rotating speed is 3000rPm, and the power is 230 Kw.

The air supply assembly 442 is connected to the air knife by a butterfly valve, a hose 447, and a quick connector. The air knife assembly further includes a height adjustment assembly 448 for adjusting the height of the air knife, by which the air knife is mounted on the fixed frame 441. The height adjusting assembly comprises a height adjusting screw rod 449 and a screw rod mounting seat 450, the screw rod mounting seat 450 is mounted on the fixing frame, the air knife is mounted at the lower end of the height adjusting screw rod, and a mounting hole for the vertical penetration of the height adjusting screw rod is formed on the screw rod mounting seat; the height adjusting screw rod is installed in the installation hole and can adjust the height of the installation hole along the vertical direction. The height adjusting screw rod is arranged on the mounting hole through a height adjusting nut 451; the outer circumferential surface of the height adjusting screw rod is provided with an external thread, and the inner circumferences of the height adjusting nut and the mounting hole are provided with internal threads matched with the external thread.

The air knife assembly 443 further includes an angle adjustment assembly 452 for adjusting the angle of the air knife, and the height adjustment assembly is mounted on the mount by the angle adjustment assembly 452. The angle adjusting assembly 452 includes an air knife rotating shaft 453, a rotating shaft mounting plate 454, and an angle adjusting nut 455 disposed at one end of the air knife rotating shaft 453, the lead screw mounting plate is mounted on the rotating shaft mounting plate through the air knife rotating shaft and is rotatable in an axial direction of the air knife rotating shaft, and the rotating shaft mounting plate is fixedly mounted on the fixing frame. The air knife sweeping distance and sweeping angle are controlled through the height adjusting assembly and the angle adjusting assembly, and accurate control of horizontal offset of the manual air knife is achieved. The surface of the air knife lip is plated with a layer of hard chromium.

As shown in fig. 15 to 18, the cooling device 5 includes an air cooling device 51 and a water cooling device 52, and the air cooling device 51 includes a cooling wind box 511 provided on the conveying member 1; the cooling air box 1 is a hollow structure, air holes 512 for feeding cold air are uniformly distributed on the inner walls of two sides of the cooling air box 1, and a cold air system 53 for conveying cold air to the cooling air box 511 is connected to the outer wall of the cooling air box 511. The hot-rolled H-shaped steel is cooled by the cold air bellows, so that a zinc layer on the surface of the H-shaped steel is cooled and solidified, the temperature of a water cooling section is ensured to be below the martensite quenching temperature of a metal matrix of the H-shaped steel, the generation of a harmful tissue structure of the steel matrix is avoided, the risk of contact between molten metal and water is solved, and explosion is prevented. In addition, the air cooling belongs to slow cooling, so that the formation of a zinc-iron alloy layer is promoted powerfully, and the zinc coating and the matrix are combined more firmly.

The air cooling is used for cooling in advance, so that the surface of a plating layer is prevented from being immediately contacted with water to generate brittle cracking and buckling phenomena, the occurrence of a martensite harmful structure after the H-shaped steel base metal is quenched by water is avoided, the steel base structure is a pearlite and ferrite structure, and the steel performance is better.

The cooling air box 511 is provided with 5 sections of cooling air boxes along the length direction of the hot rolled H-shaped steel 100, and air holes 512 for cold air inlet are uniformly distributed on the inner walls of the two sides of the 5 sections of cooling air boxes. The inner wall is punched to form an air hole, cold air cools the galvanized H-shaped steel through the air hole, and the air hole is arranged to be beneficial to cooling the H-shaped steel with a complex section. The cooling air boxes are arranged in multiple sections, the flow of cold air of each cooling air box is controlled, the cooling process of the galvanized layer on the surface of the H-shaped steel is accurately controlled, a relatively ideal cooling environment is created for the H-shaped steel, and a relatively good cooling effect is achieved.

The cold air system 53 comprises a motor 531, a first blower 532, an air cooling structure 533 and a cold air header 534, wherein the input end of the cold air header is connected with the air cooling structure, the output end of the cold air header 534 is connected with the air inlet of the cooling air box, the first blower is driven by the motor, and the air outlet of the first blower is connected with the air cooling structure. The air cooling structure comprises a condenser 535, a throttle expansion valve 536, an air conditioner evaporator 537 and a compressor 538, wherein the input end of the compressor 538 is connected with the output end of the air conditioner evaporator, the input end of the air conditioner evaporator is connected with the throttle expansion valve 536, the input end of the throttle expansion valve 536 is connected with the output end of the condenser 535, the input end of the condenser 535 is connected with the output end of the compressor 538, and the air outlet of the first blower 532 is connected with the air conditioner evaporator 537. The volume flow of the first blower 532 is 150000Nm3/h, the power of the evaporator of the air conditioner is 120KW, and the air temperature at the outlet of the cold air main pipe is 15 ℃.

The cold air header pipe 534 is communicated with each section of the cooling air box 511 through a cold air branch pipe 539. Each cooling branch pipe 539 is provided with a butterfly valve 540 and a flow meter 541 for monitoring flow. The air inlet and the outlet of the cooling wind box 511 are both provided with a temperature collector 542.

The cold air system 53 further comprises a controller, wherein the output end of the temperature collector 542 is connected with the input end of the controller 543, and the output end of the controller is connected with the input ends of the motor 531 and the air cooling structure 533. The temperature collector is used for collecting the inlet temperature and the outlet temperature of the cooling air box and feeding back the temperature to the controller, and the controller controls the motor and the air cooling structure as required to realize real-time adjustment of the cooling temperature. The cooling windbox 511 is made of a Q235 steel plate.

The water cooling device 52 includes a water cooling unit 521 provided on the transport member 1; the water cooling assembly 521 is arranged on the periphery of the hot-rolled H-shaped steel, water nozzles 522 are uniformly distributed on one side, close to the hot-rolled H-shaped steel, of the water cooling assembly 521, and gas sealing assemblies 523 are arranged at the positions of two ends of the water cooling assembly 521 on the conveying part. Set up gas seal subassembly at water-cooling subassembly both ends, with water-cooling subassembly spun water control in the middle of two gas seal subassemblies, realized the continuous water-cooling of water cooling section, avoided water to be taken next process.

The gas sealing assembly 523 comprises a high-pressure injection pipe 524 and a blower (not shown in the figure) for delivering high-pressure gas into the high-pressure injection pipe 524, wherein an outlet of the blower is connected with an inlet of the high-pressure injection pipe 524, the high-pressure injection pipe 524 is sleeved outside the hot-rolled H-shaped steel 100, and a plurality of first gas nozzles 525 are uniformly distributed on one side of the high-pressure injection pipe 524, which is close to the hot-rolled H-shaped steel 100.

The high-pressure injection pipe 524 is one of a circular ring pipe, a square pipe or an H-shaped pipe, and the air injection direction of the first air nozzle is inclined towards the water cooling assembly 521, and the inclination angle is less than 30 degrees. The H-shaped pipe refers to a high-pressure medium spray pipe structure in FIG. 5, and the circular ring-shaped pipe and the square pipe structure refer to a flushing pipe structure in FIGS. 9-10.

The water cooling unit 521 includes two or more sets of cylindrical water coolers 526 provided along the length of the conveyance member 1. The cylindrical water cooler 526 is provided at a lower side thereof with a water inlet 527 for inflow of water and at an upper side thereof with a water outlet 528 for outflow of water. The cylindrical water cooler is adopted, the upper end and the lower end of the cylindrical water cooler are connected with the water inlet pipeline, and the cylindrical nozzles are densely distributed in the cylindrical water cooler, so that the uniform cooling of the hot-rolled H-shaped steel by low-pressure large-flow water supply is realized.

The prior art cannot solve the problem of uniform water cooling after continuous galvanizing of the complicated section of the H-shaped steel, and the non-uniform water cooling causes the deformation and distortion of the hot-rolled H-shaped steel and even causes the failure of the subsequent straightening process. A multi-section low-pressure large-flow water cooler is adopted to realize the water cooling to the room temperature after the H-shaped steel is continuously galvanized, and then the straightening and calendaring processes are carried out. The design of the cylindrical water cooler and the densely arranged cooling water nozzles inside the cylindrical water cooler can realize large-flow uniform water spray cooling around the hot-rolled H-shaped steel, and the deformation of the H-shaped steel cannot be caused.

After galvanization, the temperature of the hot-rolled H-shaped steel is reduced from 150 ℃ to below 80 ℃ through water cooling so as to meet the temperature requirement of the subsequent straightening process. The hot rolling H-shaped steel continuous rolling and continuous plating process has the maximum running speed of 5m/s after rolling, needs large-flow cooling water for uniform cooling, and the water cooling process consists of a plurality of groups of cylindrical water coolers, so that the number of the water coolers can be selected according to the inlet and outlet temperatures for running. The computer model controls the size of the water inlet automatic regulating valve of the water cooler, and ensures that the temperature meets the process requirements of the next procedure.

The water cooling device 52 further comprises a water cooling circulation system 529 for recycling water in the water cooling assembly 521; the water cooling circulation system 529 comprises a trench 550, a sedimentation tank 551, a cooling tower 552, a tubular heat exchanger 553 and a water cooling module 521, wherein the trench 550 is arranged under the water cooling module 521, the sedimentation tank 551 is arranged at the water outlet of the trench 550, the water inlet of the cooling tower 552 is connected with the water outlet of the sedimentation tank 551, the water inlet of the tubular heat exchanger 553 is connected with the water outlet of the cooling tower 552, and the water cooling module 521 is arranged at the water outlet of the tubular heat exchanger 553. Considering the problem that the temperature of cooling water is lower than 20 ℃ in winter in the north, the hot-rolled H-shaped steel is easy to cool and deform due to too low water temperature, a tubular heat exchanger is additionally arranged in a water circulation system, and the temperature of the cooling water is controlled to be between 25 ℃ and 40 ℃ by utilizing the waste heat of low-grade products in a hot rolling plant.

A first water pump 554 is arranged between the settling pond 551 and the cooling tower 552, and a second water pump 555 is arranged between the cooling tower and the tubular heat exchanger. A main pipeline 556 and a branch pipeline 557 are arranged between the tube heat exchanger 553 and the water cooling module 521, the main pipeline is connected with the tube heat exchanger, and each cylindrical water cooler on the water cooling module 31 is correspondingly connected with one branch pipeline through a joint hose; the main pipeline 557 is provided with a main valve 558, and the branch pipeline is provided with an automatic regulating valve 559.

As shown in fig. 19 to 23, the straightening and burnishing system 6 includes a side-bending straightening roller 61 for straightening the side bending of the hot-rolled H-section steel 100, a horizontal straightener 62 for straightening the web of the hot-rolled H-section steel 100, a burnishing and burnishing mill 63 for flattening the surface irregularities of the hot-rolled H-section steel 100, and a edger mill 64 for straightening the upper and lower sides of the hot-rolled H-section steel 100, which are provided in the longitudinal direction of the hot-rolled H-section steel 100.

A finishing rolling mill and an edge rolling mill are additionally arranged behind the H-shaped steel cantilever roll straightening machine, and slag particles or other uneven point objects on the surface of the hot-rolled H-shaped steel are flattened, so that the surface of the hot-rolled H-shaped steel becomes smooth and flat, the high-efficiency straightening of the hot-rolled H-shaped steel is realized, and the use requirements of users are met.

The roughness of the roller of the finishing machine is controlled to adjust the surface roughness of the zinc coating on the surface of the hot-rolled H-shaped steel, so that the uneven roughness of the surface of the hot-rolled H-shaped steel can be unified to a certain range, the coating property of a product is improved, and a user can paint the product firmly.

The finishing mill 63 comprises an upper horizontal calender roll 631 arranged on the upper surface of the web of the hot-rolled H-shaped steel 100 and a lower horizontal calender roll 632 arranged on the lower surface of the web of the hot-rolled H-shaped steel, wherein the upper horizontal calender roll 631 and the lower horizontal calender roll 632 are horizontally arranged, and the plane of the central axes of the upper horizontal calender roll and the lower horizontal calender roll is vertical to the length direction of the hot-rolled H-shaped steel 100.

The finishing mill 63 further comprises a left standing calender roll 633 arranged on the outer surface of the left side plate of the hot-rolled H-shaped steel 100 and a right standing calender roll 634 arranged on the outer surface of the right side plate of the hot-rolled H-shaped steel; the lengths of the upper horizontal calender roll and the lower horizontal calender roll are equal to the width of the inner walls of the left and right side plates of the hot-rolled H-shaped steel; the left vertical calender roll and the right vertical calender roll are vertically arranged, and the plane of the central axis of the left vertical calender roll and the plane of the central axis of the right vertical calender roll are perpendicular to the length direction of the hot-rolled H-shaped steel.

The edging mill 64 comprises an upper edging roll 641 arranged on the upper edge of the hot-rolled H-shaped steel and a lower edging roll 642 arranged on the lower edge of the hot-rolled H-shaped steel, wherein the upper edging roll and the lower edging roll are horizontally arranged, and the plane of the central axes of the upper edging roll and the lower edging roll is vertical to the length direction of the hot-rolled H-shaped steel.

The front and the rear of the edging mill 64 are respectively provided with a group of the finishing mills 63, and the surface roughness of the finishing roller of the finishing mill positioned at the rear is 2.5 +/-0.25 mu m. The surface roughness of the hot-rolled H-shaped steel is unified to a certain range (1.5 +/-0.25 mu m), so that the coating property of the product is improved, and the painting of a user is firm.

The horizontal straightening machine 62 comprises a plurality of upper straightening cantilever rollers 621 arranged on the upper surface of the hot-rolled H-shaped steel web and a plurality of lower straightening cantilever rollers 622 arranged on the lower surface of the hot-rolled H-shaped steel web, wherein the upper straightening cantilever rollers and the lower straightening cantilever rollers are arranged in a staggered mode in the length direction of the hot-rolled H-shaped steel.

The horizontal straightener 62 comprises four upper straightening cantilever rollers 621 and three lower straightening cantilever rollers 622, and one lower straightening cantilever roller is arranged between the two upper straightening cantilever rollers. One end of the central shaft of each upper straightening cantilever roller 621 is driven by a motor 623, and one end of the central shaft of each upper straightening cantilever roller is provided with a straightening roller pressing cylinder 624 which applies downward pressure to the central shaft of each upper straightening cantilever roller; and one end of the central shaft of each lower straightening cantilever roller is driven by a motor.

Side bend alignment roller wheel machine 61 is including setting up a plurality of left side bend alignment roller 611 on the hot rolling H shaped steel left side board surface is in with the setting a plurality of right side bend alignment roller 612 on the hot rolling H shaped steel right side board surface, left side bend alignment roller and right side bend alignment roller are in dislocation set on the hot rolling H shaped steel length direction.

The side-bending straightening roller wheel machine 61 comprises three left side bending straightening rollers and two right side bending straightening rollers, and two left side bending straightening rollers are provided with one in the middle. In order to prevent the burnishing roller from being bonded with zinc particles, 0.5MPa of water can be added on the roller surface for washing, and a hot air drying device is added at a corresponding outlet.

As shown in fig. 24 and 25, the surface chemical passivation system 7 includes a chemical passivation device 71, the chemical passivation device 71 includes a passivation solution recovery tank 72 and a solution distribution roller assembly 73 disposed directly above the passivation solution recovery tank 72, a first air seal pipe 74 for air sealing the front and back of the hot-rolled H-shaped steel is disposed at two ends of the solution distribution roller assembly 73 in the length direction of the hot-rolled H-shaped steel 100, and the first air seal pipe 74 is sleeved on the hot-rolled H-shaped steel and is disposed at a position above the passivation solution recovery tank 72. The first air seal pipes are matched with the passivation solution recovery tank, so that chemical passivation solution sprayed by the solution distribution roller assembly always falls into the passivation solution recovery tank at the middle position of the two first air seal pipes and then enters the solution distribution roller assembly, and continuous passivation of the hot-rolled H-shaped steel is realized.

Liquid distribution roller assembly 73 includes and is located last liquid distribution roller 731 of hot rolling H shaped steel web top, is located lower liquid distribution roller 732 of hot rolling H shaped steel web below, is located left liquid distribution roller 733 in the hot rolling H shaped steel left side board outside and is located right liquid distribution roller 734 in the hot rolling H shaped steel right side board outside, go up the liquid distribution roller down the liquid distribution roller left side liquid distribution roller with all be provided with the hydrojet pipe 735 to its surface hydrojet on the liquid distribution roller. The H-shaped steel is chemically treated by adopting the nontoxic trivalent chromate passivation solution after being galvanized, a layer of salt chromate passivation film CrO3, Cr2O3, crooH and Zn-CrO4 is formed on the surface of the H-shaped steel, the oxide film is compact and has good adhesion performance, external oxygen and an internal zinc layer can be isolated, and the zinc layer on the surface of the hot-rolled H-shaped steel is effectively prevented from being oxidized. And four liquid distribution rollers, namely an upper liquid distribution roller, a lower liquid distribution roller, a left liquid distribution roller and a right liquid distribution roller, are adopted to distribute liquid on the surface of the hot-rolled H-shaped steel, so that the uniformity of liquid distribution is improved, the generation of white rust on the surface of the hot-rolled H-shaped steel is avoided, the zinc layer structure is protected, and the product quality of the hot-rolled H-shaped steel is improved.

The central axes of the upper liquid distribution roller 731 and the lower liquid distribution roller 732 are horizontally arranged, and the plane of the central axes of the upper liquid distribution roller and the lower liquid distribution roller is vertical to the length direction of the hot-rolled H-shaped steel. The length of the upper liquid distribution roller 731 and the length of the lower liquid distribution roller 732 are equal to the width of the hot-rolled H-shaped steel web.

The central axes of the left liquid distribution roller 733 and the right liquid distribution roller 734 are vertically arranged, and the plane of the central axes of the left liquid distribution roller and the right liquid distribution roller is vertical to the length direction of the hot-rolled H-shaped steel. The liquid spray pipe 735 is connected to the passivation solution recovery tank 72 by a circulating liquid pump 736.

The first air lock pipe 74 is one of a circular ring pipe, a square pipe or an H-shaped pipe, and a plurality of second air nozzles 741 are uniformly distributed on one side of the first air lock pipe 74 close to the hot-rolled H-shaped steel. The air injection direction of the second air nozzle 741 is inclined towards the liquid distribution roller assembly 73, and the inclination angle is less than 30 degrees. Wherein, the H-shaped pipe refers to the structure of the high-pressure medium spray pipe 21 in fig. 5, and the circular ring-shaped pipe and the square pipe structure refer to the structure of the flushing pipe 31 in fig. 9-10.

The surface chemical passivation system 7 further comprises a rinsing system 75 for rinsing the hot-rolled H-shaped steel 100, and the rinsing system 75 is located behind the first air seal pipe 74 at the rear end of the liquid distribution roller assembly 73. The rinsing system 75 comprises a hot water rinsing tank 751, a circulating water pump 752 and a cleaning spray pipe 753, wherein the cleaning spray pipe 753 is connected with the hot water rinsing tank 751 through the circulating water pump 752, and second air seal pipes 754 for air sealing the front and the back of the hot-rolled H-shaped steel are arranged at the positions of two ends of the cleaning spray pipe 753 in the length direction of the hot-rolled H-shaped steel 100. The waste heat steam of the heating furnace enters a coil heat exchanger at the bottom of the hot water rinsing tank through a pipeline and a regulating valve to heat the rinsing water. The temperature of the rinsing water is controlled by an automatic steam regulating valve. The water temperature measurement, the automatic regulating valve and the computer model form an automatic control closed loop system, and the waste heat steam of the heating furnace is utilized, so that the resource is saved and the carbon emission is reduced.

As shown in fig. 26 and 27, the surface chemical passivation system 7 further includes a drying system 76 for drying the passivation solution on the surface of the hot-rolled H-shaped steel 100 by hot air, the drying system 76 includes two hot air drying boxes 761, a heat exchanger 762 and a second blower 763 arranged along the length direction of the hot-rolled H-shaped steel 100, an air inlet of the hot air drying box 761 is connected with the heat exchanger 762, an air outlet of the second blower 763 is connected with an air inlet of the heat exchanger 762, and a steam inlet in the heat exchanger 762 is connected with a steam outlet of the heating furnace 764. Adopt two hot-blast drying casees to carry out hot-blast stoving to hot rolling H shaped steel surface passivation liquid, hot-blast stoving flow compares in single hot-blast drying case and increases by a wide margin, has improved the stoving effect to surface passivation liquid, has realized the quick high-efficient drying of continuous hot rolling H shaped steel surface chemical passivation liquid, is favorable to the quick formation of hot rolling H shaped steel surface passive film.

The cross section of the hot air drying box 761 is a hollow square box body, a circular box body or an H-shaped box body.

As shown in fig. 27, which is a schematic structural diagram of a square box body, the box body of the hot air drying box 761 includes an inner wall 765 and an outer wall 766, and a hot air passage 767 for hot air to pass through is formed between the inner wall 765 and the outer wall 766. An air inlet of the hot air drying box 761 is arranged on the outer wall 766 of the box body.

The inner wall 765 of the hot air drying box 761 is uniformly distributed with ventilation holes 768 for air intake. The low-quality waste heat steam which is a byproduct of the H-shaped steel heating furnace is subjected to heat exchange with air blown into the heat exchanger from the second air blower to form hot air, and the generated hot air is used for drying the passivation solution on the surface of the hot-rolled H-shaped steel, so that the comprehensive utilization of energy is realized, the consumption of fuel and carbon emission are saved, and the realization of carbon emission reduction is promoted.

A steam heat exchange tube row 769 is arranged in the heat exchanger 762, and an inlet of the steam heat exchange tube row 769 is connected with a steam outlet of the heating furnace 764.

The outlet of the heat exchange tube 769 is connected to the steam inlet of the heater 764. The exhaust port of the steam heat exchange tube is provided with an air inlet valve 770 used for controlling the air inflow of the steam. The low-quality steam (which cannot be used for steam turbine power generation) generated by cooling the water beam by the heating furnace exchanges the wind from the blower through the heat exchanger. After hot air enters the drying box, the hot-rolled H-shaped steel after chemical passivation is dried through the vent holes, and the opening of the air inlet valve of the steam pipeline is adjusted by controlling the drying temperature.

As shown in fig. 2, the present embodiment also provides a continuous hot galvanizing method for hot-rolled H-section steel, comprising the steps of:

s101, feeding hot-rolled H-shaped steel with the temperature of 850-; removing surface impurity moisture through a surface impurity moisture removing device, and controlling the temperature of the hot-rolled H-shaped steel to be 500-560 ℃;

s102, conveying the hot-rolled H-shaped steel with the impurity and water on the surface removed to a galvanizing device, and spraying a zinc layer on the surface of the hot-rolled H-shaped steel;

step S103, cooling the galvanized hot-rolled H-shaped steel by a cooling device to reduce the surface temperature of the hot-rolled H-shaped steel to be below 80 ℃;

and S104, straightening the cooled hot-rolled H-shaped steel by a straightening and finishing system, flattening slag particles or other uneven point-shaped objects on the surface of the hot-rolled H-shaped steel, and chemically passivating by a surface chemical passivation system to form a passivation film on the surface of the hot-rolled H-shaped steel.

The hot-rolled H-shaped steel is subjected to continuous hot galvanizing after being finally rolled, and subsequent galvanizing process treatment is carried out by utilizing sufficient heat of 850 ℃ high temperature after the hot-rolled H-shaped steel is finally rolled without energy consumption heating, so that the problem of high energy consumption of the hot-rolled H-shaped steel is solved, continuous production is realized, the automation degree and the yield are improved, and the galvanizing production cost of the hot-rolled H-shaped steel is greatly reduced.

The hot-rolled H-shaped steel continuous hot galvanizing detailed process comprises the following steps: the H-shaped steel heating furnace adopts a double-heat-storage walking beam type heating furnace for segmented heat storage type heating, an automatic combustion system of the heating furnace is adopted, the air-fuel ratio is set to be 0.85, the fire burning heat storage capacity is set to be 220t/H, the upper limit of the heating temperature of each segment is strictly controlled, and the coarsening of crystal grains caused by overhigh temperature is avoided while the blank is completely burnt.

The blank heats the back and is sent to high pressure water dephosphorization machine by tapping cantilever roll table and carry out the dephosphorization, and wherein water pressure is 18Mpa, sprays effective width and is 500mm, and 1 set of nozzle quantity of annular collector is 25 sets, and the nozzle interval is 50mm, and it is 160mm apart from the slab upper surface height to go up the nozzle, total water consumption: the flow rate is 18m3/h, so that the blank iron scale is removed.

And carrying out reversible rolling on the billet after dephosphorization by a BD rolling mill, wherein the maximum rolling pressure is 8500kN, the diameter of a roller is 850-1420mm, the reduction speed is 0-10mm/s, the maximum reduction stroke is 550mm, the power of a main transmission motor is 5600kW, the rotating speed is 40-130rpm, the section shape required by a finishing mill group, namely an intermediate billet, is rolled out, a pusher and a tilter are arranged at the front and the rear of the BD rolling mill, the pusher guides the billet into a hole pattern, the tilter turns the billet if necessary, and the BD rolling mill generally rolls 3-9 times according to different product specifications and the billet used. After the intermediate billet rolled by the BD passes through a hot shearing head, the maximum shearing force is 4200kN, the shearing speed is 0.3-1.3m/s, the minimum shearing temperature is 880 ℃, and the length of a shearing edge is 720 mm. The steel wire rope is sent into a continuously arranged finishing mill group through a roller way for final forming rolling, the rolling process of the finishing mill group is automatic rolling, and the frames adopt micro-tension control and have a cascade speed regulation function.

The finishing mill group comprises 11 rolling mills, wherein the first rolling mill is a universal variable two-roll rolling mill, the third rolling mill, the seventh rolling mill and the tenth rolling mill are edging mills, the center distance of the edging mill rolls is 850 plus 1050mm, the specification of the rolls is phi 1000 multiplied by 1100mm, the axial adjustment amount is +/-5 mm, and the transverse displacement amount of the rolling mill is +/-5 mm; the rest is a universal rolling mill, the working center distance of the horizontal roll is 1150-950mm, the working center distance of the vertical roll is 1250-950mm, the horizontal rolling force is max550T, the rolling force of the vertical roll is max260T, the main transmission of the finishing mill group is independent transmission, and the maximum outlet speed of the finishing mill group is 5 m/s.

In the dephosphorization process of the H-shaped steel before plating by using high-pressure water, the pressure of the high-pressure water is 15-20MPa, the included angle between the water spraying direction of a nozzle and the vertical direction is 15 degrees, and the total water consumption in unit time is 18m 3/H.

In the process of rinsing and removing the surface moisture and impurities of the hot-rolled H-shaped steel by high-pressure air and low-pressure clean water, 2 groups of low-pressure water and high-pressure air devices are alternately arranged, wherein the flow rate of the low-pressure clean water is 60m3/H, the pressure is 0.25MPa, the temperature is 20 +/-10 ℃, and the pressure of the high-pressure air is 0.4-0.6 MPa.

The temperature of hot-rolled H-shaped steel entering a hot galvanizing pool is 560-500 ℃, the temperature of an air inlet cooling device is 450-470 ℃, the volume flow of an air blower of the air cooling device is 150000Nm3/H, the power of an air conditioner evaporator is 120KW, and the air temperature of an outlet of a cold air main pipe is 15 ℃. The temperature of a water inlet cooling device for hot-rolled H-shaped steel is 180-120 ℃, the volume flow of water cooling in the water cooling device is 350m3/H, and the water spraying pressure is 0.35 MPa.

The temperature of the hot-rolled H-shaped steel entering a straightening calender is less than or equal to 80 ℃, and the surface roughness range of the hot-rolled H-shaped steel is 1.5 +/-0.25 mu m. The hot water rinsing temperature after passivation is 60-65 ℃, and the hot air drying temperature is 50 +/-10 ℃. The passivation solution adopts a formula of a trivalent chromate passivator: 3-50g/L of chromium chlorate, 125g/L of sodium nitrate, 50g/L of sodium fluoride, 5.0g/L of acidic silica sol, 8.0g/L of zinc powder and the balance of deionized water.

The thickness of the hot-rolled H-shaped steel pure zinc layer is controlled to be 80-600g per square meter, and the thickness of the chemical passivation film coating is controlled to be 15-30mg per square meter.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The continuous hot galvanizing production line for the hot-rolled H-shaped steel is characterized by comprising a conveying part, and a high-pressure water dephosphorization device, a surface impurity moisture clearing device, a galvanizing device, a cooling device, a straightening finishing system and a surface chemical passivation system which are sequentially arranged on the conveying part from front to back.

2. The continuous hot galvanizing production line for the hot-rolled H-shaped steel according to claim 1, wherein the high-pressure water dephosphorization device comprises a high-pressure medium spray pipe for spraying water on the surface of the hot-rolled H-shaped steel, the high-pressure medium spray pipe is an H-shaped pipe arranged around the outer side face of the hot-rolled H-shaped steel, and a high-pressure medium nozzle is formed on one side, close to the surface of the hot-rolled H-shaped steel, of the high-pressure medium spray pipe.

3. The continuous hot galvanizing line for hot-rolled H-shaped steel according to claim 1, wherein the surface impurity moisture removing device comprises a flushing pipe for flushing the surface of the hot-rolled H-shaped steel and a high-pressure purging pipe for assisting in cleaning, the flushing pipe and the high-pressure purging pipe are sleeved on the hot-rolled H-shaped steel along the length direction of the hot-rolled H-shaped steel, a flushing nozzle is formed on the flushing pipe on the side close to the surface of the hot-rolled H-shaped steel, and a high-pressure purging nozzle is formed on the high-pressure purging pipe on the side close to the surface of the hot-rolled H-shaped steel.

4. The continuous hot galvanizing line for hot-rolled H-shaped steel according to claim 1, wherein the galvanizing device comprises a strip-shaped groove-shaped galvanizing kettle, a roller assembly arranged in the length direction of the galvanizing kettle and used for conveying the hot-rolled H-shaped steel, and a molten zinc spraying pipe assembly used for spraying molten zinc in the galvanizing kettle on the surface of the hot-rolled H-shaped steel, and the galvanizing kettle is arranged right below the molten zinc spraying pipe assembly.

5. The hot-rolled H-shaped steel continuous hot galvanizing production line according to claim 4, wherein the zinc liquid spray pipe assembly comprises a zinc liquid axial flow pump, a hydraulic motor, a zinc liquid spray pipe and a zinc liquid spray nozzle, the zinc liquid axial flow pump is arranged in the galvanizing kettle, the zinc liquid axial flow pump and the hydraulic motor and the zinc liquid spray pipe are connected through pipelines, and the zinc liquid spray nozzle is arranged on the zinc liquid spray pipe; the liquid zinc spray pipe is sleeved on the periphery of the hot-rolled H-shaped steel, and a plurality of liquid zinc spray nozzles are arranged on one side of the liquid zinc spray pipe, which is close to the surface of the hot-rolled H-shaped steel.

6. A hot-rolled H-shaped steel continuous hot galvanizing line according to claim 1, wherein the cooling device comprises an air cooling device and a water cooling device, and the air cooling device comprises a cooling wind box arranged on the conveying part; the cooling air box is of a hollow structure, air holes for feeding cold air are uniformly distributed in the inner walls of two sides of the cooling air box, and the outer wall of the cooling air box is connected with a cold air system for conveying cold air to the cooling air box.

7. A hot rolled H-shaped steel continuous hot galvanizing line according to claim 6, wherein the water cooling device comprises a water cooling assembly arranged on the conveying part; the water cooling assembly is arranged on the periphery of the hot-rolled H-shaped steel and is close to one side of the hot-rolled H-shaped steel, water spray nozzles are uniformly distributed on the side, close to the hot-rolled H-shaped steel, of the water cooling assembly, and gas sealing assemblies are arranged at the positions of the two ends of the water cooling assembly on the conveying part.

8. The continuous hot galvanizing line for the hot-rolled H-shaped steel according to claim 1, wherein the straightening finishing system comprises a side-bending straightening roller machine arranged in the length direction of the hot-rolled H-shaped steel and used for straightening the side bending of the hot-rolled H-shaped steel, a horizontal straightener used for straightening a web plate of the hot-rolled H-shaped steel, a finishing mill used for flattening the surface unevenness of the hot-rolled H-shaped steel and a edging mill used for straightening the upper edge and the lower edge of the hot-rolled H-shaped steel.

9. The continuous hot galvanizing production line for the hot-rolled H-shaped steel according to claim 1, wherein the surface chemical passivation system comprises a chemical passivation device, the chemical passivation device comprises a passivation solution recovery tank and a solution distribution roller assembly arranged right above the passivation solution recovery tank, first air sealing pipes for air sealing the front and the back of the hot-rolled H-shaped steel are arranged at positions at two ends of the solution distribution roller assembly in the length direction of the hot-rolled H-shaped steel, and the first air sealing pipes are sleeved on the hot-rolled H-shaped steel and are arranged at positions above the passivation solution recovery tank.

10. A continuous hot galvanizing method for hot-rolled H-shaped steel is characterized by comprising the following steps:

step one, feeding hot-rolled H-shaped steel with the temperature of 850-; removing surface impurity moisture through a surface impurity moisture removing device, and controlling the temperature of the hot-rolled H-shaped steel to be 500-560 ℃;