Novel rolling mill outlet nitrogen purging device
By designing a water retaining trough and a nitrogen purge device at the rolling mill outlet, the problem of emulsion residue at the rolling mill outlet was solved, and the quality of cold-rolled products and resource utilization efficiency were improved.
Patent Information
- Application Number
- CN202423159550.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-09-19
- Estimated Expiration
- 2034-12-20
AI Technical Summary
During the cold rolling process, the nitrogen purge effect at the mill outlet is poor, resulting in emulsion residue on the strip surface, forming chemical stain defects and affecting product quality.
A new type of nitrogen purge device at the rolling mill outlet is designed, including a water retaining trough, upper and lower nitrogen purge devices and a T-shaped retaining frame, which is used to effectively purge the emulsion and high-temperature oil mist steam on the upper and lower surfaces of the strip to prevent residue.
It achieves no emulsion residue on the strip surface, improves the cleanliness of the plate surface, reduces emulsion loss and production costs, and eliminates the backflow effect of high-temperature oil mist steam.
Smart Images
Figure CN223352557U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of cold rolling. Background Art
[0002] Emulsion plays a crucial role in the cold rolling process as a lubricant and cooling medium. Failure to adequately purge the emulsion from the plate surface during rolling can significantly impact the quality of the finished plate. Currently, the biggest challenge facing domestic rolling mills is the ineffective purge of emulsion from the plate surface, resulting in residual emulsion staining (ranging from brown to black depending on severity). Therefore, residual emulsion is a major issue hindering cold rolling mills from improving product quality.
[0003] When nitrogen purge at the mill exit is ineffective, emulsion residue can often be seen on the upper and lower surfaces of the strip exiting the final stand during high-speed rolling. After a period of stagnation, continuous yellow stains appear on the strip surface when uncoiled. These stains cannot be completely eliminated even after cleaning and annealing. This affects product quality. Even after galvanizing, the emulsion residue remains noticeable, leading to white spot defects.
[0004] According to on-site observations and analysis, during high-speed rolling, rolling oil primarily flows from the mill's inlet side or is carried to the mill's outlet side through the work roll gap, the work rollers, the ends of the backup rolls, and the roll surfaces. The rotating work rollers and backup rolls pick up the oil entering the outlet, causing it to splash onto the strip surface. This is especially true when rolling thicker strips, where the roll gap outside the strip is larger, resulting in more severe splashing on both sides of the rolls (i.e., at the roll necks).
[0005] The existing design of the rolling mill outlet takes into account the liquid on the plate surface caused by the splash of emulsion during the rolling process of the rolling mill, but only sets an inclined water baffle on the upper surface, while ignoring the liquid on the plate surface caused by steam reflux caused by high temperature. Utility Model Content
[0006] The technical problem to be solved by the utility model is: how to solve the problem that during the high-speed rolling process of the rolling mill, the emulsion splashed by the rotating rollers (working rollers) and the oil mist steam generated by the high temperature will drip onto the surface of the strip and cause emulsion residue.
[0007] The technical solution adopted by the present invention is: a new type of nitrogen purging device at the rolling mill outlet, the strip is conveyed from left to right after leaving the rolling mill outlet, the strip is between the upper working roll 2 and the lower working roll 1, the upper working roll 2 is above the upper support 4, and the lower working roll 1 is below the lower support 3, the nitrogen purging device includes a water retaining groove 6 located on the upper side of the plane where the strip is located and on the right side of the rolling mill outlet, an upper nitrogen purging device 7 located on the upper side of the plane where the strip is located and for purging the strip below the water retaining groove 6, a lower nitrogen purging device 5 located on the lower side of the plane where the strip is located and out of the rolling mill outlet, a T-shaped cross-section retaining frame 8 located on the lower side of the plane where the strip is located and on the right side of the lower nitrogen purging device 5, and a lower oil removal roller 9 located on the lower side of the plane where the strip is located and on the right side of the retaining frame 8.
[0008] The water retaining trough 6 includes a horizontal plate 61 parallel to the strip steel, an inclined plate 62 connected to the right side of the horizontal plate 61 and forming an angle of 90-135° with the horizontal plate 61, a horizontal plate front edge 63 on the left side of the horizontal plate 61, a horizontal plate front edge 64 and a horizontal plate rear edge 65 on the front and rear sides of the horizontal plate 61, and an inclined plate front edge 66 and an inclined plate rear edge 67 on the front and rear sides of the inclined plate 62.
[0009] The top of the inclined plate 62 is higher than the top of the upper working roll 2 .
[0010] The retaining frame 8 includes a lower guide plate 81 parallel to the strip and a vertical plate 82 at the center of the lower guide plate 81 and perpendicular to the lower guide plate 81.
[0011] The level of the bottom of the vertical plate 82 is lower than the level of the lower working roll 3.
[0012] The beneficial effects of the utility model are as follows: after adopting the utility model, no emulsion residue is left on the upper and lower surfaces of the strip at the rolling mill outlet, thereby improving the cleanliness of the strip plate surface; reducing the loss of emulsion, which would otherwise be carried away in large quantities if the rolling oil is not purged cleanly, while increasing the production cost of the product; and eliminating the liquid on the strip plate surface caused by the reflux of oil mist vapor due to high temperature, which can be drained to the emulsion system. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 It is a schematic diagram of the overall structure of the utility model;
[0014] Figure 2 This is a schematic diagram of the water retaining trough structure of the utility model;
[0015] Figure 3 This is a schematic diagram of the structure of the retaining frame of the utility model;
[0016] Among them, 1. lower working roller, 2. upper working roller, 3. lower support, 4. upper support, 5. lower nitrogen purge device, 6. water retaining trough, 7. upper nitrogen purge device, 8. retaining frame, 9. lower degreasing roller. DETAILED DESCRIPTION
[0017] like Figure 1-3 As shown in the figure, a new type of nitrogen purge device at the mill outlet is used. After the strip leaves the mill outlet, it is transported from left to right and is located between the upper working roll 2 and the lower working roll 1. The strip is transported by the upper working roll 2 and the lower working roll 1 (both the upper working roll 2 and the lower working roll 1 are multiple, with attached Figure 1 Only the upper working roll 2 and the lower working roll 1 at the mill exit are drawn).
[0018] Above the upper work roll 2 is the upper support 4, and below the lower work roll 1 is the lower support 3. The upper support 4 here generally refers to the device that provides support for the upper work roll 2 and drives its rotation, and is conventional. The same applies to the lower support 3. In conventional technology, the emulsion splashed by the rotating rolls (upper and lower work rolls) at the exit and the oil mist vapor generated by the high temperature can drip onto the strip surface, leaving a noticeable emulsion residue, which can lead to white spot defects in later products.
[0019] The nitrogen purging device of the present invention includes a water retaining trough 6 located on the upper side of the plane where the strip is located and on the right side of the rolling mill outlet, an upper nitrogen purging device 7 located on the upper side of the plane where the strip is located and used to purge the strip below the water retaining trough 6, a lower nitrogen purging device 5 located on the lower side of the plane where the strip is located and at the rolling mill outlet, a retaining frame 8 with a T-shaped cross-section located on the lower side of the plane where the strip is located and on the right side of the lower nitrogen purging device 5, and a lower oil removal roller 9 located on the lower side of the plane where the strip is located and on the right side of the retaining frame 8.
[0020] The water retaining trough 6 receives the emulsion splashed on the upper side of the strip and the emulsion of the oil mist steam reflux caused by the high temperature, and avoids the emulsion from remaining on the upper surface of the strip. The retaining frame 8 blocks the emulsion splashed on the lower side of the strip.
[0021] The lower nitrogen purge device 5 and the upper nitrogen purge device 7 both adopt nitrogen purge devices of the prior art to purge the surface of the steel strip with nitrogen.
[0022] In one embodiment, the water retaining trough 6 includes a horizontal plate 61 parallel to the strip steel, an inclined plate 62 connected to the right side of the horizontal plate 61 and forming an angle of 90-135° with the horizontal plate 61, a horizontal plate front edge 63 on the left side of the horizontal plate 61, a horizontal plate front edge 64 and a horizontal plate rear edge 65 on the front and rear sides of the horizontal plate 61, and an inclined plate front edge 66 and an inclined plate rear edge 67 on the front and rear sides of the inclined plate 62.
[0023] In one embodiment, the top of the inclined plate 62 is at a level higher than that of the upper working roll 2 .
[0024] In one embodiment, the retaining frame 8 includes a lower guide plate 81 parallel to the steel strip and a vertical plate 82 located at the center of the lower guide plate 81 and perpendicular to the lower guide plate 81. Both the lower guide plate 81 and the vertical plate 82 are rectangular plates.
[0025] In one embodiment, the level of the bottom of the vertical plate 82 is lower than the level of the lower working roll 3.
Claims
1. A novel nitrogen purge device at the mill outlet, wherein the strip is conveyed from left to right after leaving the mill outlet, the strip is located between the upper working roll (2) and the lower working roll (1), the upper part of the upper working roll (2) is provided with an upper support (4), and the lower part of the lower working roll (1) is provided with a lower support (3), and the device is characterized in that: The nitrogen purging device comprises a water retaining trough (6) located on the upper side of the plane where the steel strip is located and on the right side of the rolling mill outlet, an upper nitrogen purging device (7) located on the upper side of the plane where the steel strip is located and used for purging the steel strip below the water retaining trough (6), a lower nitrogen purging device (5) located on the lower side of the plane where the steel strip is located and at the rolling mill outlet, a retaining frame (8) with a T-shaped cross section located on the lower side of the plane where the steel strip is located and on the right side of the lower nitrogen purging device (5), and a lower degreasing roller (9) located on the lower side of the plane where the steel strip is located and on the right side of the retaining frame (8).
2. A novel nitrogen purge device for rolling mill outlet according to claim 1, characterized in that: The water retaining trough (6) includes a horizontal plate (61) parallel to the strip steel, an inclined plate (62) connected to the right side of the horizontal plate (61) and forming an angle of 90-135 degrees with the horizontal plate (61), a horizontal plate front edge (63) on the left side of the horizontal plate (61), a horizontal plate front edge (64) and a horizontal plate rear edge (65) on the front and rear sides of the horizontal plate (61), and an inclined plate front edge (66) and an inclined plate rear edge (67) on the front and rear sides of the inclined plate (62).
3. The novel rolling mill outlet nitrogen purge device according to claim 2, characterized in that: The level of the top of the inclined plate (62) is higher than the level of the upper working roll (2).
4. The novel nitrogen purge device at the rolling mill outlet according to claim 1 is characterized in that: The retaining frame (8) includes a lower guide plate (81) parallel to the strip steel and a vertical plate (82) located at the center of the lower guide plate (81) and perpendicular to the lower guide plate (81).
5. The novel nitrogen purge device at the rolling mill outlet according to claim 4 is characterized in that: The level of the bottom of the vertical plate (82) is lower than the level of the lower working roll (1).