Small-caliber cast steel pipe burial pit

Abstract

The utility model discloses a minor-caliber cast steel pipe burial pit which comprises a pipe hanging pit and a heat preservation pit which are divided by a partition wall, an outlet is formed in the bottom of the partition wall, and a double-leaf outlet curtain is installed on the outlet. A box body cover covers the heat preservation pit, and a double-leaf inlet curtain is arranged at an inlet of the box body cover. A plurality of inclined rails are arranged in the heat preservation pit, and buffering turning assemblies are installed at the falling ends of the cast steel pipes of the upper and lower adjacent rails so as to buffer falling of the cast steel pipes. The bottom end of an arc plate of the buffering turning assembly is rotationally connected with a small shaft fixed to the lower-layer rail, the arc line of the bottom end is tangent to the surface of the lower-layer rail, and a spring is installed between the back face of the arc plate and the pit wall to buffer impact of the cast steel pipe. And a buffer pad is mounted on the arc surface of the arc plate, so that impact noise can be eliminated. The first-in first-out device realizes first-in first-out of the cast steel pipe, and is suitable for continuous production of small-caliber cast steel pipes.

Description

Technical Field

[0001] This utility model is applied in the field of centrifugal casting and relates to the slow cooling of cast steel pipes, specifically a slow cooling pit suitable for slow cooling of small-diameter cast steel pipes. Background Technology

[0002] Thick-walled cast steel pipes are typically used as industrial raw materials. After centrifugal casting, they undergo hot processing, such as hot rolling, hot extrusion, or other methods, to become semi-finished products. To improve the production efficiency of thick-walled cast steel pipes, they are often pushed or pulled while still red-hot. Cast steel pipes that are not sensitive to thermal stress can be air-cooled, but those that are sensitive to thermal stress need to be pushed into a slow-cooling pit or furnace for slow cooling.

[0003] For rapidly cooling austenitic steels, depending on the steel grade, direct water cooling can be used for rapid entry into the next process. However, for most alloy steels, slow cooling is often used to reduce casting stress. Therefore, slow cooling furnaces or slow cooling pits are often built next to centrifuges. CN203284430U (energy-saving slow cooling pit), CN221724912U (a new type of heated slow cooling pit furnace heated by burners), and CN218026236U (an electric heating device for a slow cooling pit with heat preservation function) are all equivalent to heated heat preservation furnaces. CN202555786U (a new type of environmentally friendly and safe heating device for a slow cooling pit using waste heat from a hot air furnace), and CN218059104U (a slow cooling pit for cast steel pipes using waste gas from a ladle drying process) are suitable for cyclical operations and cannot ensure that cast steel pipes that enter the slow cooling pit first exit first. Utility Model Content

[0004] The technical problem solved by this utility model is to provide a slow cooling pit for small-diameter cast steel pipes, in which the cast steel pipes roll back and forth on multiple tracks within the pit to achieve first-in, first-out.

[0005] The technical solution adopted in this utility model is as follows: The small-diameter cast steel pipe slow cooling pit of this utility model includes a pipe hanging pit and an insulation pit separated by a partition wall. The bottom of the partition wall is the outlet, and an outlet curtain is installed on the outlet. The insulation pit is covered with a box cover, and an inlet curtain is installed at the inlet of the box cover. An odd number of inclined tracks are set inside the insulation pit, preferably three or five layers. At the ends of the cast steel pipe falling between two adjacent layers of tracks, buffer and deflection components are installed to buffer the falling cast steel pipe.

[0006] Furthermore, the buffer deflection assembly includes an arc plate and an arc-shaped leaf spring. The lower end of the leaf spring is fixed to and tangential to the lower track, while the upper end maintains an elastic distance from the fixed arc plate. A buffer pad is installed on the arc surface of the leaf spring.

[0007] Furthermore, the buffer deflection assembly includes a spring, an arc plate, and a small shaft; the bottom end of the arc plate is rotatably connected to the small shaft, the small shaft is fixed to the lower track, and the spring is installed between the back of the arc plate and the pit wall to buffer the impact of the cast steel pipe. A buffer pad is installed on the arc surface of the arc plate to increase the buffering effect and help eliminate impact noise. The arc at the bottom end of the arc plate is tangent to the track surface of the lower track to prevent the cast steel pipe from bumping against it.

[0008] Furthermore, the arc plate is replaced with a diagonal bar, which does not affect the rolling of the cast steel pipe to the lower track.

[0009] Furthermore, the outlet curtain and the inlet curtain are double-leaf curtains, and the distance between the double-leaf curtains is not less than twice the diameter of the cast steel pipe. When the cast steel pipe rolls, at least one curtain seals the opening to prevent air exchange and flow within the insulation pit. An electromagnetic stop block is installed on the bottom of the pit on the inner side of the outlet inner curtain to block or release the cast steel pipes one by one.

[0010] The beneficial effects of this utility model are: This utility model allows cast steel pipes to enter and exit through the inlet and outlet at both ends of the slow cooling pit, achieving first-in, first-out (FIFO) operation of the cast steel pipes, and is suitable for continuous production of small-diameter cast steel pipes. The double-sided curtain hinders airflow within the insulation pit, helping to keep the insulation pit in a state of slow cooling and heat preservation. Attached Figure Description

[0011] Figure 1 This is the main view of the structure in Embodiment 1, and also... Figure 2 A schematic diagram of the AA cross-section;

[0012] Figure 2 for Figure 1 Top view (without the box cover);

[0013] Figure 3 for Figure 1 BB cross-sectional diagram;

[0014] Figure 4 for Figure 1 A magnified view of a portion of the image;

[0015] Figure 5 This is a partial schematic diagram of Example 2;

[0016] Figure 6 This is a partial schematic diagram of Example 3;

[0017] Figure 7 This is a partial schematic diagram of Example 4;

[0018] Among them: 1-Import curtain, 2-Inner curtain, 3-Box cover, 4-Upper rail, 5-Cast steel pipe, 6-Buffer and deflection assembly, 7-Partition wall, 8-Hanging pipe pit, 9-Exit curtain, 10-Lower rail, 11-Interval rail, 12-Insulation pit, 13-Insulation wall, 14-Horizontal support rod, 15-Stop block;

[0019] 61-Spring, 62-Arc plate, 63-Buffer pad, 64-Small shaft, 65-Firming plate, 66-Padded block, 67-Diagonal bar, 68-Leaf spring. Detailed Implementation

[0020] Example

[0021] The structure of the slow-cooling pit in this embodiment is shown in the attached figure. Figure 1-4 As shown, the system includes a pipe-lifting pit 8 and an insulation pit 12. The pipe-lifting pit 8 is used to lift out the cast steel pipe 5, or a chain-driven lifting device can be installed to transport the cast steel pipe out of the pipe-lifting pit 8. The two pits are separated by a partition wall 7, and a cast steel pipe outlet is provided at the bottom of the partition wall 7. An outlet curtain 9 is installed on the outlet to block airflow.

[0022] A box cover 3 covers the insulation pit 12. The box cover 3 can be hoisted or moved with wheels. The gap between the box cover and the ground is sealed, and the installed heat-insulating layer provides insulation. An inlet curtain 1 is installed at the inlet where the cast steel pipe of the box cover rolls in. To enhance the insulation effect and impede airflow, an inner curtain 2 is installed on the box cover inside the inlet. Both the inlet curtain 1 and the inner curtain 2 are in contact with the ground, sealing the cross-sectional space of the inlet and the box cover without contacting the cast steel pipe 5. To ensure the insulation effect of the double inlet curtains, the distance between the inlet curtain 1 and the inner curtain 2 is not less than the diameter of two cast steel pipes. The inlet curtain, inner curtain, and outlet curtain do not affect the rolling of the cast steel pipe on the track and can block airflow, ensuring the slow cooling effect of the cast steel pipe in the insulation pit.

[0023] The insulation pit 12 is equipped with three layers of tracks: the upper track 4, the middle track 11, and the lower track 10 at the bottom. These three tracks are inclined to facilitate the automatic rolling of the cast steel pipes. The suspended upper track 4 and middle track 11 are supported by horizontal support rods 14 fixed to the insulation wall 13 of the pit. Buffer and deflection components 6 are installed at the ends where the cast steel pipes fall between adjacent upper and lower tracks.

[0024] The structure of buffer reversal component 6 is shown in the attached figure. Figure 4As shown, the system includes a spring 61, an arc plate 62, and a small shaft 64. A buffer pad 63 should be installed on the arc surface of the arc plate 62 to buffer the impact between the cast steel pipe and the arc plate, and also to reduce expansion noise. To increase the strength of the arc plate, a stiffening rib 65 is provided on the back of the arc plate. The bottom end of the arc plate is rotatably connected to the small shaft 64, which is fixed to the lower track. The spring 61 is installed between the back of the arc plate and the insulated wall 13 of the pit wall. To fix the spring 61, the spring cooperates with a pad 66 on the back of the arc plate. The arc at the bottom end of the arc plate should be tangent to the track surface of the lower track to prevent the cast steel pipe from colliding due to unevenness at the junction of the track and the arc plate.

[0025] In this embodiment, the high-temperature cast steel pipe rolls in through the inlet on the box cover. The inlet curtain flips inward, at which point the inner curtain is closed, and the air inside the holding furnace does not circulate. When the cast steel pipe flips inward through the inner curtain, the inlet curtain closes again, and the air inside the holding furnace remains closed. Subsequently, the cast steel pipe rolls into the upper rail and automatically rolls down the inclined upper rail to the end. As the cast steel pipe falls in a parabolic trajectory, it impacts the buffer and deflection assembly. Both the buffer pad and the spring provide cushioning. When the spring is compressed, the arc plate rotates around the small axis, and the position of the bottom end of the arc plate remains basically unchanged. Then, the cast steel pipe rolls automatically along the inclined intermediate rail. When the cast steel pipe rolls to the end of the intermediate rail, it falls in a parabolic trajectory, impacts the buffer and deflection assembly, enters the lower rail, and automatically rolls along the inclined lower rail. After flipping outward through the outlet curtain, it rolls into the hanging pipe pit. Example

[0026] In Example 1, the outlet curtain 9 has only one curtain. When the cast steel pipe rolls out of the insulation pit, cold air from the pipe-hanging pit inevitably enters the insulation pit. To prevent cold air from entering, a double curtain is also installed at the outlet position, as shown in the attached diagram. Figure 5 As shown. An inner curtain 2 is also installed inside the furnace at the outlet curtain 9, and both curtains are sealed to the pit floor. To ensure at least one sealed outlet, the distance between the two curtains is no less than twice the diameter of the cast steel pipe.

[0027] A stop block 15 is installed on the bottom of the pit inside the inner curtain. The stop block 15 is electromagnetic. When the power is off, the top of the movable block of the stop block 15 springs up under the action of the spring, preventing the cast steel pipe from rolling. However, when the power is on, the movable block is magnetically attracted and moves downward, and the cast steel pipe rolls out of the outlet along the inclined lower rail under the action of gravity. This achieves the release and lifting of each pipe one by one. Example

[0028] This embodiment is an improvement on the buffer reversing assembly in the above embodiments, replacing the arc plate with the inclined rod 67, as shown in the attached figure. Figure 6 As shown, it does not affect the rolling of the cast steel pipe to the lower track. Compared with the buffer deflection assembly using the arc plate, the buffer deflection assembly using the diagonal bar 67 has the same structure, but the diagonal bar size is simpler. Example

[0029] This embodiment provides another structure for the buffer reversal component, as shown in the attached diagram. Figure 7 As shown, in Embodiment 1, the spring is replaced by a leaf spring 68. The leaf spring 68 is arc-shaped, with its lower end fixed to the lower track and tangent to the track, while its upper end maintains an elastic distance from the arc plate 62, which is fixed. Although this structure is simple, it requires a special leaf spring.

[0030] A cushioning pad can also be installed on the curved surface of the plate to enhance cushioning and eliminate impact noise.

[0031] Additional notes: 1) Due to the small diameter of the cast steel pipe, the drop height from the upper track to the lower track is small. Protected by springs and buffer pads, the cast steel pipe will not bend or deform. 2) To ensure the curtains effectively block airflow, double curtains can be replaced with multiple curtains. 3) The distance between the curtains depends not only on the diameter of the cast steel pipe but also on the height of the doorway. If the distance between the curtains is greater than twice the diameter of the cast steel pipe, at least one curtain will remain closed, thus preventing airflow between the insulation pit and the outside. 4) An odd number of tracks, preferably three or five layers, should be arranged inside the insulation pit so that the cast steel pipe enters from one end and exits from the other, facilitating the loading and unloading of the pipe.

[0032] This invention achieves first-in, first-out (FIFO) operation of cast steel pipes by continuously rolling them within an insulation pit, making it highly suitable for continuous production of small-diameter cast steel pipes. The curtain does not interfere with the pipes' entry and exit from the insulation pit; in particular, the double-sided curtain effectively hinders airflow within the pit, helping to maintain a state of slow cooling and insulation. The multi-layered, folding rolling of the cast steel pipes within the insulation pit reduces its footprint.

Claims

1. A slow-cooling pit for small-bore cast-steel pipes, characterized by: It comprises a hanging pipe pit and a heat preservation pit separated by a partition wall; the bottom of the partition wall is an outlet, and a curtain is installed on the outlet; a box cover is installed on the heat preservation pit, and an inlet curtain is installed on the inlet of the box cover; an odd number of inclined rails are installed in the heat preservation pit, and a buffer and direction changing assembly is installed at the end of the falling cast steel pipe on the upper and lower adjacent two layers of rails.

2. The slow cooling pit for small-bore cast steel pipes according to claim 1, characterized in that: The buffer and direction changing assembly comprises an arc plate and an arc plate spring, the lower end of the plate spring is fixed on the relative lower layer of rails and is tangent to the rails, and the upper end and the fixed arc plate leave an elastic distance.

3. The slow cooling pit for small-bore cast steel pipes according to claim 2, characterized in that: A buffer pad is installed on the arc surface of the plate spring.

4. The slow cooling pit for small-bore cast steel pipes according to claim 1, characterized in that: The buffer and direction changing assembly comprises a spring, an arc plate and a small shaft; the bottom end of the arc plate is rotationally connected with the small shaft, the small shaft is fixed on the relative lower layer of rails, and the spring is installed between the back of the arc plate and the pit wall; the bottom end arc line of the arc plate is tangent to the rail surface of the relative lower layer of rails.

5. The slow cooling pit for small-bore cast steel pipes according to claim 4, characterized in that: A buffer pad is installed on the arc surface of the arc plate or the plate spring.

6. The slow-cooling pit for small-bore cast-steel pipes according to claim 4, characterized in that: The arc plate is replaced by a diagonal rod.

7. The slow-cooling pit for small-bore cast-steel pipes according to claim 1, characterized in that: The outlet curtain and the inlet curtain are double-leaf curtains.

8. The slow-cooling pit for small-bore cast-steel pipes according to claim 7, characterized in that: The distance of the double-leaf curtain is not less than twice the diameter of the cast steel pipe.

9. The slow-cooling pit for small-bore cast-steel pipes according to claim 7, characterized in that: An electromagnetic stopper is installed on the inner side of the pit bottom of the outlet curtain.

10. The slow-cooling pit for small-bore cast-steel pipes according to claim 1, characterized in that: The odd number is three or five.

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