Steam heating box type steel coil heat preservation device

Abstract

The invention provides a steam heating box type steel coil heat preservation device which comprises a heat preservation box, a radiator adopting steam for heat supply is arranged in the heat preservation box, the inlet end of the radiator is communicated with a steam supply pipeline, the outlet end of the radiator is communicated with a first condensate water recycling pipeline, and the inlet end of the radiator is higher than the outlet end of the radiator. The steam supply pipeline and the first condensate water recovery pipeline both extend out of the heat preservation box, and a first drain valve is arranged on the first condensate water recovery pipeline and located outside the heat preservation box. The first drain valve at the outlet of the radiator can drain condensate water in time, and it is guaranteed that the heat exchange efficiency of the radiator is always kept at a high level. According to the invention, the requirement of rapid temperature rise of the steel coil can be met, the temperature of the supplied steel coil is maintained in a proper interval, and the continuity and stability of subsequent rolling production can be ensured. And steam is used as a heat source medium, so that environmental protection and high safety are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steel coil heat preservation or temperature rising before strip rolling, in particular to a steam heating box type steel coil heat preservation device. BACKGROUND

[0002] Because the incoming material temperature is low and the strip breaking rate is high during rolling in the current production of high-grade non-oriented silicon steel products, a steel coil heat preservation and heating device is arranged before the rolling mill to try to increase the temperature of the steel coil entering the rolling mill to improve the plate passing property and reduce the strip breaking rate.

[0003] However, the existing steel coil heat preservation and heating device can only ensure that the temperature of the placed steel coil is maintained above the required minimum initial temperature or the temperature of the steel coil is slightly increased, because of the limitations of the heating method and the heat source medium conditions, the steel coil cannot be rapidly heated to meet the production speed of the rolling mill, and the continuity and stability of the subsequent rolling production cannot be guaranteed. In addition, some heat source media are not environmentally friendly and safe.

[0004] Therefore, it is necessary to design a steam heating box type steel coil heat preservation device to overcome the above problems. SUMMARY

[0005] The present application aims to overcome the defects of the prior art and provide a steam heating box type steel coil heat preservation device to ensure that the temperature of the steel coil is maintained in a suitable range when the production rhythm of the rolling mill is not smooth, and to ensure the continuity and stability of the subsequent rolling production. The present application at least solves some problems in the prior art.

[0006] The present application is implemented as follows:

[0007] The present application provides a steam heating box type steel coil heat preservation device, which comprises a heat preservation box, a radiator using steam heating is arranged in the heat preservation box, the inlet end of the radiator is in communication with a steam supply pipeline, the outlet end of the radiator is in communication with a first condensate water recovery pipeline, the inlet end of the radiator is higher than the outlet end of the radiator, the steam supply pipeline and the first condensate water recovery pipeline both extend out of the heat preservation box, a first drain valve is arranged on the first condensate water recovery pipeline, and the first drain valve is located outside the heat preservation box.

[0008] Further, an air temperature sensor probe is arranged in the heat preservation box, a flow regulating valve is arranged on the steam supply pipeline, and the flow regulating valve is located outside the heat preservation box.

[0009] Further, a centrifugal fan is arranged on the top of the heat preservation box.

[0010] Further, the walls of the heat preservation box are composed of an inner metal plate, a heat preservation layer and an outer metal plate from inside to outside.

[0011] Further, the first condensate water recovery pipeline has a smaller diameter than the steam supply pipeline.

[0012] Further, the bottom of the steam supply pipeline is connected with a second condensate water recovery pipeline, which is located outside the heat preservation box, and a second trap valve is arranged on the second condensate water recovery pipeline.

[0013] Further, the end of the first condensate water recovery pipeline and the end of the second condensate water recovery pipeline are both connected with a condensate water tank.

[0014] Further, the steam heating box type steel coil heat preservation device further comprises a coil carrying trolley running on a track, the track extends to below the heat preservation box, the bottom plate of the heat preservation box near the box door is provided with an opening matched with the coil carrying trolley, and the upper surface height of the bottom plate of the heat preservation box is consistent with the upper surface height of the coil carrying trolley.

[0015] Further, the upper surface of the coil carrying trolley is provided with a steel coil saddle for placing a steel coil.

[0016] Further, the end of the track is provided with a limiting stopper.

[0017] The present application has the following beneficial effects:

[0018] 1. Steam is used as a heat source medium, and the latent heat of vaporization is huge. When high-temperature steam is condensed into water in the radiator, a large amount of condensation heat is released, which can quickly establish the required high-temperature environment in the heat preservation box and provide sufficient heat basis for the steel coil heating. The present application can meet the requirement of rapidly heating the steel coil, maintain the temperature of the incoming steel coil in a suitable range, and ensure the continuity and stability of the subsequent rolling production. Moreover, using steam as a heat source medium is environmentally friendly and has high safety.

[0019] 2. The first trap valve at the outlet of the radiator can timely discharge condensate water, so as to ensure that the heat exchange efficiency of the radiator is always maintained at a high level.

[0020] 3. The present application can accurately control the steam amount entering the radiator and the heating power by real-time monitoring the temperature in the heat preservation box through the air temperature sensor, comparing the temperature with the set temperature value of the heat preservation box, and adjusting the opening degree of the flow regulating valve on the steam supply pipeline. This feedback control ensures that the temperature in the heat preservation box can quickly reach and stabilize at the set value, avoids slow heating of the steel coil due to too low temperature, or energy waste and equipment loss due to too high temperature. This feedback control makes the whole system always operate under the optimal working condition, provides stability guarantee for realizing rapid heating.

[0021] 4. The centrifugal fan increases the hot air flow rate in the heat preservation box, thereby increasing the convective heat transfer coefficient between the steel coil and the hot air in the heat preservation box, greatly increasing the heat transferred from the air to the steel coil per unit time, and making the heating speed faster.

[0022] 5. The walls of the heat preservation box are filled with heat insulation materials, effectively blocking the heat conduction from the heat preservation box to the outside.

[0023] 6. The operator can select different box temperatures according to the needs of the production process to heat or heat the steel coil, which is simple and easy to operate; the heat preservation box can be built in a limited space or outside the limit position of the overhead crane, making full use of the space; because there is a coil transporting car to transport the steel coil, the heat preservation box can be built in a position that the overhead crane cannot directly reach.

[0024] 7. The device of the present application has a simple structure, and the number of heat preservation boxes can be selected according to the process rhythm (whether the rolling mill needs a large number of heated steel coils) and the heat preservation time required by the incoming steel coil, which is simple and convenient to use. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without any creative effort.

[0026] Figure 1 A perspective view of the steam heating box type steel coil heat preservation device provided by the embodiment of the present application;

[0027] Figure 2 A schematic view of the heat radiator in the heat preservation box body provided by the embodiment of the present application;

[0028] Figure 3 A connection schematic view of the steam supply pipeline, the heat radiator, and the first condensate water recovery pipeline provided by the embodiment of the present application.

[0029] In the figure: 1, heat preservation box; 2, coil transporting car; 3, track; 4, steam heating system; 5, steam supply pipeline; 6, heat radiator; 7, first condensate water recovery pipeline; 8, flow regulating valve; 9, first trap; 10, centrifugal fan; 11, stop valve; 12, second condensate water recovery pipeline; 13, thermal resistance; 14, second trap; 15, condensate water tank; 16, ball valve. DETAILED DESCRIPTION

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0032] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0033] like Figures 1-3 This invention provides a steam-heated box-type steel coil insulation device, including an insulation box 1. The insulation box 1 is equipped with a steam-heated radiator 6. The inlet end of the radiator 6 is connected to a steam supply pipeline 5, which is equipped with insulation measures. The outlet end of the radiator 6 is connected to a first condensate recovery pipeline 7. Figure 3The inlet end of radiator 6 is higher than the outlet end of radiator 6 (steam must enter from the top and exit from the bottom when passing through the radiator). Both the steam supply pipe 5 and the first condensate recovery pipe 7 extend out of the insulation box 1. The first condensate recovery pipe 7 at the radiator outlet is equipped with a steam trap assembly, which includes a first steam trap 9, two shut-off valves located at both ends of the first steam trap 9, and a shut-off valve on the parallel bypass of the first steam trap 9. The first steam trap 9 can promptly discharge condensate and prevent steam from escaping, ensuring that the heat exchange efficiency of the radiator is always maintained at a high level. Steam, as a heat source medium, has a huge latent heat of vaporization. When high-temperature steam condenses into water in the radiator, it releases a large amount of condensation heat, which can quickly establish the required high-temperature environment in the insulation box, providing a sufficient heat base for heating the steel coil. This invention can meet the requirement of rapidly heating the steel coil, maintaining the temperature of the incoming steel coil within a suitable range, and ensuring the continuity and stability of subsequent rolling production. Moreover, using steam as a heat source medium is both environmentally friendly and highly safe. To prevent steam leakage from the first condensate recovery pipe 7, the diameter of the first condensate recovery pipe 7 can be designed to be smaller. The bottom of the steam supply pipe 5 is connected to the second condensate recovery pipe 12, which is located outside the insulation box 1. The second condensate recovery pipe 12 is equipped with a second steam trap 14 and is used to drain the condensate in the steam supply pipe 5. The ends of both the first condensate recovery pipe 7 and the second condensate recovery pipe 12 are connected to the condensate tank 15. During the flow of steam in the steam supply pipe 5, heat is released, generating some condensate. The high-speed flowing steam pushes the condensate accumulated in the steam supply pipe 5, creating a huge impact force, producing violent vibrations and loud noises, i.e., "water hammer." Water hammer has great destructive power and can damage valves, fittings, and even the equipment itself, posing a serious safety hazard. The second condensate recovery pipe helps to drain the condensate in the steam supply pipe 5 in a timely manner, preventing its accumulation.

[0034] An air temperature sensor probe is installed inside the insulation box 1. In this embodiment, the air temperature sensor is a resistance temperature detector (RTD) 13. A flow regulating valve group is installed on the steam supply pipeline 5 at the radiator inlet. The flow regulating valve group includes a flow regulating valve 8, two shut-off valves located at both ends of the flow regulating valve 8, and a shut-off valve on the parallel bypass of the flow regulating valve 8. The control system (such as a PLC) compares the actual temperature value measured by the air temperature sensor with the set temperature value of the insulation box 1. When the actual temperature value is lower than the set temperature value, the control system will increase the opening of the flow regulating valve 8 to allow more steam to enter the radiator, causing the air temperature inside the insulation box 1 to rise. When the actual temperature value is higher than the set temperature value, the control system will determine that heating needs to be reduced or stopped. The control system will reduce the opening of the flow regulating valve 8 to reduce or even cut off the steam supply to prevent the temperature from becoming too high and achieve precise temperature control. The flow regulating valve group and the drain valve group are both located outside the insulation box 1. The air temperature sensor, the flow regulating valve group, and the drain valve group are all electrically connected to the control system.

[0035] A centrifugal fan 10 is installed on the top of the insulation box 1. The centrifugal fan 10 is used to increase the airflow velocity inside the insulation box 1, thereby increasing the convective heat transfer coefficient between the steel coil and the hot air inside the insulation box 1. The impeller of the centrifugal fan 10 is immersed in the insulation box, and the motor drive of the centrifugal fan 10 is located in the ambient air outside the insulation box. The centrifugal fan 10 is electrically connected to the control system.

[0036] This invention employs a steam heating system 4, which has a simple and uncomplicated structure. The end of the steam heating system 4 consists of a radiator suspended on the inner side wall of the insulated box and valves (ball valves 16) for inlet and outlet of the radiator. The steam heating system 4 includes steam as the heat source medium, steam supply pipelines, a radiator, a first condensate recovery pipeline, and a second condensate recovery pipeline. Existing steam resources can be used, saving costs.

[0037] The insulated box 1 is composed of a metal frame and box walls. The insulated box 1 is rectangular in shape. The box walls are, from the inside to the outside, an inner metal plate, an insulation layer, and an outer metal plate. The insulation layer is made of heat-insulating material. The metal plate can be made of steel plate. The internal space of the insulated box 1 can accommodate the largest steel coil and heating equipment such as radiators. The bottom of the insulated box 1 is equipped with support legs.

[0038] The steam-heated box-type steel coil insulation device also includes a coil-carrying trolley 2 that travels on track 3. Track 3 extends below the insulation box 1, with one end of track 3 serving as the coil receiving position and the other end as the insulation position. When the coil-carrying trolley 2 stops at the coil receiving position, the overhead crane places the steel coil onto the trolley 2. The front of the insulation box 1 has a cylinder-driven, automatically opening and closing door. The cylinder is electrically connected to the control system, and the door opens to allow the coil-carrying trolley 2 to enter. The bottom plate of the insulation box 1 near the door has a notch adapted to the coil-carrying trolley 2. The upper surface of the bottom plate of the insulation box 1 is the same height as the upper surface of the coil-carrying trolley 2. When the coil-carrying trolley 2 stops at the insulation position (limit position), its upper surface just fills the notch on the bottom plate of the insulation box. When the door of the insulation box 1 is closed, the entire insulation box 1 forms a completely enclosed space. High-temperature resistant flexible sealing strips can be used to enhance the sealing effect at the gaps in the insulation box 1.

[0039] The coil transport trolley 2 is a two-axle, four-wheel flatbed trolley. Its upper surface is equipped with a coil saddle for placing steel coils. The trolley 2 is driven by a motor, which is electrically connected to the control system. The motor is suspended below the side of the trolley's panel and can move back and forth along the track 3 between the coil receiving position and the insulation position. Insulation material needs to be laid under the upper surface of the coil transport trolley 2 to reduce heat loss.

[0040] Track 3 is equipped with control switches for deceleration positions and limit positions (heat preservation positions) to ensure the smooth operation of the winding trolley 2. A first proximity switch is installed at the deceleration position, and a second proximity switch is installed at the heat preservation position. Both the first and second proximity switches are electrically connected to the control system (such as a PLC). The winding trolley 2 starts from the receiving position and travels towards the heat preservation box 1 at a relatively high normal operating speed. When the trolley reaches the preset "deceleration position" on track 3, the first proximity switch is triggered, sending a signal to the control system: "The trolley has entered the deceleration zone." Upon receiving the signal, the control system immediately instructs the drive motor to reduce speed, allowing the winding trolley 2 to continue moving forward at a low speed. When the winding trolley 2 moves into the detection range of the second proximity switch, the second proximity switch sends an electrical signal to the control system, indicating that the winding trolley 2 has reached the "heat preservation position." Based on this signal, the control system immediately cuts off the power to the drive motor, and the winding trolley 2 comes to a smooth stop.

[0041] Mechanical limit blocks are installed on track 3 to restrict the movement of the trolley within the normal working range of the track, preventing the winding trolley 2 from slipping off the track. When an electrical fault causes the winding trolley 2 to run out of its limit position, the limit blocks physically stop the winding trolley 2.

[0042] The present invention can select the number of insulation boxes 1 according to the process rhythm. The insulation boxes 1 correspond one-to-one with the winding trolley 2 and the track 3. The steam heating system of each insulation box can be set in parallel and controlled and adjusted separately.

[0043] The heat source can also be selected as superheated water or heat transfer oil depending on the medium conditions of the unit. The heat transfer oil can also be heated by electric heating or gas heating. The terminal facilities are the same as those of this invention, and it has a wide range of applications.

[0044] Figure 1 The right side is the receiving position. After the coil transport trolley 2 stops at the receiving position, the overhead crane places the steel coil on the coil saddle on the coil transport trolley 2. Then, under the action of the drive motor, the coil transport trolley 2 moves towards the insulation box 1. A higher running speed can be selected in the first half of the movement, and the running speed is reduced near the deceleration position of the insulation box 1 to ensure that the coil transport trolley 2 stops smoothly at the left insulation position. After the second proximity switch detects that the trolley has stopped at the insulation position, it sends a signal to the control system. The control system controls the door of the insulation box 1 to close automatically, and the insulation box 1 enters the heating mode. The radiator and centrifugal fan start working to insulate or heat the steel coil. After the steel coil is heated, the insulation box door of the insulation box 1 opens automatically, the radiator and centrifugal fan stop working, and the coil transport trolley 2 begins to move from the insulation position to the receiving position, waiting for the overhead crane to lift the heated steel coil away for production. The control programs involved in the above process are all existing and will not be described in detail here.

[0045] Figure 2 This serves as the terminal steam radiator in the steam heating system 4. Simultaneously, a temperature sensor with local digital display and remote transmission capabilities can be installed inside the insulation box to detect the air temperature within the box. This sensor, in turn, provides feedback control with the steam flow regulating valve on the steam pipeline, saving energy consumption while ensuring heating efficiency.

[0046] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A steam-heated box-type steel coil insulation device, characterized in that: The device includes an insulated box, inside which is a radiator heated by steam. The inlet end of the radiator is connected to a steam supply pipeline, and the outlet end of the radiator is connected to a first condensate recovery pipeline. The inlet end of the radiator is higher than the outlet end of the radiator. Both the steam supply pipeline and the first condensate recovery pipeline extend out of the insulated box. A first steam trap is provided on the first condensate recovery pipeline, and the first steam trap is located outside the insulated box.

2. The steam-heated box-type steel coil insulation device as described in claim 1, characterized in that: The insulation box is equipped with an air temperature sensor probe, and the steam supply pipeline is equipped with a flow regulating valve located outside the insulation box.

3. The steam-heated box-type steel coil insulation device as described in claim 1, characterized in that: The top of the insulated box is equipped with a centrifugal fan.

4. The steam-heated box-type steel coil insulation device as described in claim 1, characterized in that: The walls of the insulated box, from the inside out, consist of an inner metal plate, an insulation layer, and an outer metal plate.

5. The steam-heated box-type steel coil insulation device as described in claim 1, characterized in that: The diameter of the first condensate recovery pipeline is smaller than the diameter of the steam supply pipeline.

6. The steam-heated box-type steel coil insulation device as described in claim 1, characterized in that: The bottom of the steam supply pipeline is connected to the second condensate recovery pipeline, which is located outside the insulation box and is equipped with a second steam trap.

7. The steam-heated box-type steel coil insulation device as described in claim 6, characterized in that: The ends of the first condensate recovery pipeline and the second condensate recovery pipeline are both connected to the condensate tank.

8. The steam-heated box-type steel coil insulation device as described in claim 7, characterized in that: It also includes a coil-carrying trolley that travels on a track that extends to the bottom of the insulated box. The bottom plate of the insulated box near the door has a notch that is adapted to the coil-carrying trolley. The height of the upper surface of the bottom plate of the insulated box is the same as the height of the upper surface of the coil-carrying trolley.

9. The steam-heated box-type steel coil insulation device as described in claim 8, characterized in that: The upper surface of the coil transport trolley is provided with a coil saddle for placing the steel coil.

10. The steam-heated box-type steel coil insulation device as described in claim 8, characterized in that: The end of the track is provided with a limiting stop.

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