CN114350928B

CN114350928B - Homogenization cryogenic treatment method for roller and cryogenic treatment tank adopted by homogenization cryogenic treatment method

Info

Publication number: CN114350928B
Application number: CN202111619863.3A
Authority: CN
Inventors: 王文明; 兰勇; 胡现龙; 陈伟; 高伟
Original assignee: Baosteel Roll Science & Technology Co ltd
Current assignee: Baosteel Roll Science & Technology Co ltd
Priority date: 2021-12-28
Filing date: 2021-12-28
Publication date: 2023-04-28
Anticipated expiration: 2041-12-28
Also published as: CN114350928A

Abstract

The invention discloses a homogenization deep-cooling treatment method and a deep-cooling treatment tank adopted by the homogenization deep-cooling treatment method; the homogenizing deep cooling treatment method comprises the following steps: (1) placing the roller in a cryogenic treatment tank; a liquid nitrogen nozzle is arranged in the cryogenic treatment tank; a group of uniform atomizing devices are arranged on the outer side of each liquid nitrogen nozzle; (2) the roller is lifted to the distance of 250-350 mm from the bottom of the tank by the liftable sizing block, then the ultralow temperature electromagnetic valve is controlled by the control system, liquid nitrogen is sent into each liquid nitrogen nozzle from the liquid nitrogen storage tank through the liquid nitrogen spray pipe, and the roller is subjected to cryogenic treatment by the uniform atomization device. The method of the invention not only can realize the homogenization deep cooling treatment of the surface of the roller, but also can realize the homogenization deep cooling treatment of the interior of the roller by optimizing the deep cooling treatment tank, including the number, the structure, the position relation with the roller and the like of the nozzles and designing the corresponding uniform atomizing device, thereby effectively solving the problem of exceeding the standard of vortex soft points.

Description

Homogenization cryogenic treatment method for roller and cryogenic treatment tank adopted by homogenization cryogenic treatment method

Technical Field

The invention belongs to the technical field of cryogenic treatment, and particularly relates to a homogenizing cryogenic treatment method for a roller and a cryogenic treatment tank adopted by the homogenizing cryogenic treatment method.

Background

At present, the cryogenic treatment of the roller mainly adopts a liquid nitrogen direct spraying mode. Chinese patent document CN103468918A makes the ejected liquid nitrogen in a fine mist form by installing a mesh enclosure at the nozzle of the liquid nitrogen nozzle. The Chinese patent document CN110684890A effectively improves the hardness uniformity of the roller finished product by designing a novel nozzle.

However, the research focus of the above two documents is mainly to control the surface temperature of the roller in the process of cryogenic treatment, and the temperature control of the interior of the roller is not effectively studied, but the existing cryogenic treatment mode has the problem of exceeding the vortex soft point, which is directly related to the cryogenic temperature control of the interior of the roller.

Disclosure of Invention

The invention aims to solve the problems and provide a homogenization deep cooling treatment method for a roller and a deep cooling treatment tank adopted by the homogenization deep cooling treatment method.

The technical scheme for realizing the aim of the invention is as follows: a homogenization deep-cooling treatment method of a roller comprises the following steps:

(1) placing the roller in a cryogenic treatment tank;

the deep cooling treatment tank is provided with a tank bottom, long inner walls on the left side and the right side, and short inner walls on the front side and the rear side; two liftable sizing blocks for controlling the height of the roller are arranged on the bottom of the groove; an upper groove and a lower groove are respectively arranged on the long inner walls at the left side and the right side; 6-20 liquid nitrogen nozzles are arranged in each groove; a group of uniform atomizing devices are arranged on the outer side of each liquid nitrogen nozzle; the uniform atomizing device comprises a baffle and a pumping net; the baffle is provided with a body, four supporting legs used for being welded and fixed with the long inner wall and an L-shaped fixed block welded and fixed on each supporting leg; a hole which is convenient for the blocking net to be inserted is reserved between each L-shaped fixed block and the body; the middle part of the body is of a hollow structure; the pumping net is matched with a hollow structure in the middle of the body of the baffle plate;

(2) the roller is lifted to the distance of 250-350 mm from the bottom of the tank by the liftable sizing block, then the ultralow temperature electromagnetic valve is controlled by the control system, liquid nitrogen is sent into each liquid nitrogen nozzle from the liquid nitrogen storage tank through the liquid nitrogen spray pipe, and the roller is subjected to cryogenic treatment by the uniform atomization device.

The distance between the uniform atomizing device and the liquid nitrogen nozzle is 20-100 mm, preferably 40-60 mm.

The distance between the liquid nitrogen nozzles in the upper and lower grooves and the bottom of the groove is 700-900 mm and 250-350 mm respectively; the distance between two adjacent liquid nitrogen nozzles is 480-520 mm.

The liquid nitrogen nozzles comprise a multi-nozzle liquid nitrogen nozzle and a single-nozzle liquid nitrogen nozzle; the multi-nozzle liquid nitrogen nozzle is used for spraying the roller body.

The mesh size of the extraction net is 10 to 100 mesh, preferably 20 to 50 mesh, more preferably 40 mesh.

The invention has the positive effects that: the method of the invention not only can realize the homogenization deep cooling treatment of the surface of the roller, but also can realize the homogenization deep cooling treatment of the interior of the roller by optimizing the deep cooling treatment tank, including the number, the structure, the position relation with the roller and the like of the nozzles and designing the corresponding uniform atomizing device, thereby effectively solving the problem of exceeding the standard of vortex soft points.

Drawings

FIG. 1 is a schematic diagram of a cryogenic tank according to the present invention.

Fig. 2 is a view in the direction a in fig. 1.

Fig. 3 is a view in the direction B of fig. 1.

Fig. 4 is a front view of the uniform atomizing device of the present invention.

Fig. 5 is a left side view of fig. 4.

Fig. 6 is a top view of fig. 4.

Fig. 7 is a schematic diagram of the structure of the multi-head liquid nitrogen nozzle in fig. 2.

Fig. 8 is a right side view of fig. 7.

Fig. 9 is a schematic diagram of the structure of the single-head liquid nitrogen nozzle in fig. 2.

Fig. 10 is a right side view of fig. 9.

Fig. 11 is a schematic view of a temperature measuring point on a roll.

FIG. 12 is a graph of the cryogenic treatment cooling process of example 1 (40 mesh screen).

FIG. 13 is a graph of the cryogenic treatment cooling process of example 2 (20 mesh screen).

FIG. 14 is a graph of the cryogenic treatment cooling process of comparative example 1 (no screen).

Detailed Description

Example 1

The material of the roll in this example was 20# steel, and the specification was Φ560mm×2000mm×3600mm.

The homogenization deep-cooling treatment method of the roller of the embodiment comprises the following steps:

(1) the roll 100 is placed in the cryogenic treatment tank 1.

Referring to fig. 1 to 3, the deep-cooling treatment tank 1 of the present embodiment has a tank bottom 1-1, long inner walls 1-2 on the left and right sides, and short inner walls 1-3 on the front and rear sides, and a tank cover (not shown) is required to be covered during deep-cooling treatment.

Two liftable sizing blocks 2 for controlling the height of the roller 100 are arranged on the groove bottom 1-1.

The long inner walls 1-2 on the left side and the right side are respectively provided with an upper groove 1-2-1 and a lower groove 1-2 (see figure 2); 12 liquid nitrogen nozzles 3 (namely 48 liquid nitrogen nozzles in the total in the embodiment) are arranged in each groove 1-2-1; a group of uniform atomizing devices 4 are arranged outside each liquid nitrogen nozzle 3, and the distance between the uniform atomizing devices 4 and the liquid nitrogen nozzles 3 is 50mm (see figure 1).

Of these, the liquid nitrogen nozzles (3) in the upper two grooves (1-2-1) are inclined downward, and the liquid nitrogen nozzles in the lower two grooves 1-2-1 are inclined upward (see fig. 1).

The distance between the liquid nitrogen nozzles 3 in the upper and lower grooves 1-2-1 and the groove bottom 1-1 is 800mm and 300mm respectively, and the distance between the adjacent two liquid nitrogen nozzles 3 is 500mm (see figure 2).

Referring to fig. 2 and 7-10, the middle 6 (square frame part in fig. 2, toward the roller body) liquid nitrogen nozzles in each groove 1-2-1 are multi-nozzle liquid nitrogen nozzles 31, namely novel nozzles related to embodiment 1 of chinese patent document CN110684890a, while the other 6 liquid nitrogen nozzles are single-nozzle liquid nitrogen nozzles 32, namely existing nozzles related to background section of chinese patent document CN110684890 a.

Referring to fig. 4 to 6, the uniform atomizing device 4 includes a baffle 41 and a screen 42.

The baffle 41 has a body 41-1, four legs 41-2 for welding fixation with the long inner wall 1-2, and an L-shaped fixing block 41-3 welded fixation on each leg 41-2. A hole for facilitating the insertion of the blocking net 42 is left between each L-shaped fixing block 41-1 and the body 41-1. The middle part of the body 31-1 is hollow.

The mesh 42 is matched with the hollow structure in the middle of the body 41-1 of the baffle 41, and the mesh size of the mesh 42 in this embodiment is 40 mesh.

(2) The roller 100 is lifted to 300mm away from the tank bottom 1-1 by the liftable sizing block 2 (namely, the distance between the roller and the tank bottom 1-1 is the same as that between the liquid nitrogen nozzles 3 in the two grooves below) and then the ultra-low temperature electromagnetic valve is controlled by the control system, liquid nitrogen is sent into the liquid nitrogen nozzles 3 from the liquid nitrogen storage tank through the liquid nitrogen spray pipe, and the roller 100 is subjected to cryogenic treatment by the uniform atomizing device 4.

In the process of cryogenic treatment, temperature detection is carried out on four temperature measuring points on the roller 100, the arrangement of the temperature measuring points is shown in fig. 11 and table 1, and the temperature measuring result is shown in the cryogenic treatment cooling process curve of fig. 12.

TABLE 1

Temperature measuring point	A	B	C	D
					Radial depth (distance from roll surface)	0	30mm	35mm	45mm
Axial depth (distance from roll end face)	350mm	350mm	350mm	350mm

Example 2

Substantially the same as in example 1, except that: the mesh size of the drawing net 42 of the uniform atomizing device 4 is 20 meshes, and the temperature measurement result is shown in the cryogenic treatment cooling process curve of fig. 13.

Comparative example 1

Substantially the same as in example 1, except that: the outside of the liquid nitrogen nozzle 3 is not provided with a uniform atomizing device 4, and the temperature measurement result is shown in the cryogenic treatment cooling process curve of fig. 14.

As can be seen from fig. 12 to 14:

without the addition of a uniform atomizing device (fig. 14): the surface temperature of the roll body reaches-50 ℃ about 3 hours, and the time required for reaching-50 ℃ from the position 30-45 mm away from the surface of the roll body is basically the same, and the time is about 4 hours.

With 20 mesh draw added (fig. 13): about 2 hours, namely the surface temperature of the roller body reaches 50 ℃ below zero, the temperature of the roller body at a position 30-45 mm away from the surface of the roller body reaches 50 ℃ below zero basically the same, and the roller body is prolonged for 2 hours by 6 hours, which shows that the roller has better homogenization effect.

With an increase of 40 mesh draw (fig. 12): the surface temperature of the roll body reaches 50 ℃ below zero in about 2 hours, the temperature of the roll body at a position 30-45 mm away from the surface of the roll body reaches 50 ℃ below zero basically the same, and the roll body needs 6.5 hours and is prolonged for 2.5 hours, so that the roll has better homogenization effect.

Claims

1. A homogenization deep-cooling treatment method of a roller comprises the following steps:

(1) placing a roller (100) in a cryogenic treatment tank (1);

the deep cooling treatment tank (1) is provided with a tank bottom (1-1), long inner walls (1-2) at the left side and the right side, and short inner walls (1-3) at the front side and the rear side;

two liftable sizing blocks (2) for controlling the height of the roller (100) are arranged on the bottom (1-1) of the groove;

the long inner walls (1-2) on the left side and the right side are respectively provided with an upper groove (1-2-1) and a lower groove (2-1); 6-20 liquid nitrogen nozzles (3) are arranged in each groove (1-2-1); a group of uniform atomizing devices (4) are arranged on the outer side of each liquid nitrogen nozzle (3); the distance between the uniform atomizing device (4) and the liquid nitrogen nozzle (3) is 40-60 mm; the distance between the liquid nitrogen nozzle (3) in the upper and lower grooves (1-2-1) and the groove bottom (1-1) is 700-900 mm and 250-350 mm respectively; the distance between two adjacent liquid nitrogen nozzles (3) is 480-520 mm; the liquid nitrogen nozzle (3) comprises a multi-nozzle liquid nitrogen nozzle (31) and a single-nozzle liquid nitrogen nozzle (32); the multi-nozzle liquid nitrogen nozzle (31) is used for spraying the roller body;

the uniform atomizing device (4) comprises a baffle (41) and a pumping net (42);

the baffle (41) is provided with a body (41-1), four supporting legs (41-2) for welding and fixing with the long inner wall (1-2) and an L-shaped fixing block (41-3) welded and fixed on each supporting leg (41-2); a hole which is convenient for the insertion of the drawing net (42) is reserved between each L-shaped fixed block (41-3) and the body (41-1); the middle part of the body (41-1) is of a hollow structure;

the pumping net (42) is matched with a hollow structure in the middle of the body (41-1) of the baffle (41);

(2) the roller (100) is lifted to be 250-350 mm away from the tank bottom (1-1) through the lifting sizing block (2), then the ultralow temperature electromagnetic valve is controlled through the control system, liquid nitrogen is sent into each liquid nitrogen nozzle (3) from the liquid nitrogen storage tank through the liquid nitrogen spray pipe, and the roller (100) is subjected to cryogenic treatment through the uniform atomizing device (4).

2. The homogenizing cryogenic treatment method of a roll of claim 1, wherein: the mesh size of the drawing net (42) is 20-50 meshes.

3. A cryogenic treatment tank; has a groove bottom (1-1), long inner walls (1-2) on the left and right sides and short inner walls (1-3) on the front and rear sides; the method is characterized in that:

the pumping net (42) is matched with a hollow structure in the middle of the body (41-1) of the baffle plate (41).

4. A cryogenic treatment tank according to claim 3, characterized in that: the mesh size of the drawing net (42) is 20-50 meshes.