Radiation square box electric heating furnace

Abstract

A radiation square box electric heating furnace sequentially comprises a square box furnace steel structure, a square box furnace wall plate and a heat insulation lining from outside to inside. The whole shell is supported by the square box furnace steel structure, the square box furnace steel structure is connected with the square box furnace wall plate in a welded mode, and the heat insulation lining is arranged on the inner side of the wall plate and plays a role in heat insulation. The furnace tubes are horizontally arranged in an inner cavity of the square box furnace, a medium flows from top to bottom along each row of furnace tubes, certain spaces are reserved for the furnace tubes from top to bottom every three or more rows to insert the electric heating tubes, and the electric heating tubes and the furnace tubes are arranged at 90 degrees. The furnace tubes are arranged in multiple columns in the horizontal direction, and the distance between every two columns is 1.5 times of the tube center distance or multiple times of the tube center distance. The overall structure of the furnace body is a square box type structure, the furnace tubes and the electric heating tubes are distributed in the square box type structure in a transversely and vertically staggered mode, and the space in the square box type furnace is utilized to the maximum extent.

Description

Technical Field

[0001] The device belongs to the technical field of petrochemical heating furnaces, and relates to a radiation square box electric heating furnace specially used for heating various process media in the petrochemical industry. Background Art

[0002] In the existing petrochemical industry, most process heating furnaces are gas-fired. However, these furnaces have numerous drawbacks and produce significant carbon emissions, placing significant pressure on the environment. Furthermore, they emit pollutants such as nitrogen oxides during operation, which violates environmental regulations.

[0003] In addition, the gas heating furnace requires a complex combustion control system, which increases the equipment footprint and poses a safety hazard of gas leakage, posing a potential threat to production safety.

[0004] The burners in the radiation chamber of a gas-fired furnace primarily radiate heat. The burners are spaced relatively far from the furnace tubes to prevent overheating, which results in the radiation chamber occupying a significant amount of space. Electric heating, without radiation convection, would reduce the floor space and furnace volume, saving significant investment.

[0005] In contrast, the radiation square box electric heating furnace of the present invention can completely replace the oil-fired or gas-fired process heating furnaces in the petrochemical industry and is suitable for heating various process media. Summary of the Invention

[0006] This device provides a radiation square box electric heating furnace. The overall structure adopts a square box structure. The interior is filled with furnace tubes and electric heating tubes in a horizontal and vertical staggered manner, which maximizes the use of the furnace space inside the square box furnace, reduces investment and reduces floor space.

[0007] The specific structure of a radiation square box electric heating furnace is as follows:

[0008] From the outside to the inside, they are the square box furnace steel structure, the square box furnace wall panels, and the thermal insulation lining. The square box furnace steel structure is used to support the entire shell. The square box furnace steel structure is welded to the square box furnace wall panels. The inner side of the wall panels is provided with a thermal insulation lining to play a role in thermal insulation. The furnace tubes are arranged horizontally in the inner cavity of the square box furnace. The medium flows from top to bottom along each row of furnace tubes. A certain space is left every 3 rows (or multiple rows) of furnace tubes from top to bottom to insert the electric heating tubes. The electric heating tubes and the furnace tubes are arranged at 90° to each other. The furnace tubes are arranged in multiple rows in the horizontal direction, and the spacing between each row is 1.5 times the tube center distance (or multiple times the tube center distance). The furnace tubes are distributed throughout the entire square box furnace cavity. According to the heating requirements of the process medium, each row of furnace tubes can be one tube pass or multiple rows of furnace tubes can be one tube pass.

[0009] The electric heating tube is inserted into the furnace cavity from the side (from one side for small furnaces and from both sides for large furnaces). It provides heat to the furnace. A flanged sleeve is installed on the side of the furnace, connecting it to the furnace cavity. The electric heating tube passes through the sleeve and enters the furnace. The flange cover at the end of the electric heating tube is bolted to the sleeve flange. An explosion-proof junction box is installed at the end of the electric heating tube, which has control and power inlet ports. The electric heating tube is equipped with a temperature measuring element.

[0010] The entire electric radiation box furnace is a fully enclosed structure, filled with nitrogen inert protective gas to protect the electric heating tubes from oxidation. The box furnace is equipped with an inert gas replenishment system, which automatically replenishes inert gas when the pressure in the furnace cavity decreases.

[0011] Further features include that the inner core of the electric heating tube is a heating resistance wire, the casing is made of high alloy steel (or a suitable material is selected according to the characteristics of the heating medium and the operating temperature), and magnesium oxide powder is filled between the resistance wire and the casing for insulation treatment to ensure the safe and reliable operation of the electric heating tube.

[0012] Furthermore, the explosion-proof junction box can be equipped with an explosion-proof rating of up to DIICT4, depending on the site requirements, meeting the high explosion-proof requirements of the petrochemical industry. The protection level can reach IP65 and above, making it suitable for outdoor installation environments, enhancing the adaptability and safety of the equipment.

[0013] Furthermore, the electric heating tubes are equipped with temperature measuring elements and an over-temperature interlock protection system. When the temperature exceeds the set point, the system automatically stops heating to prevent damage from overheating. Furthermore, temperature measuring elements are installed at the inlet and outlet of the medium. By monitoring the inlet and outlet temperatures in real time, the power of the heating tubes can be adjusted to achieve precise temperature control, meeting the needs of processes with high temperature control requirements.

[0014] A further feature is that the protective gas in the shell can be other inert protective gases besides nitrogen.

[0015] Further features include various arrangements of horizontal coils, vertical coils, etc. for protecting the furnace tubes to meet the heating needs of different process media and equipment space layout requirements.

[0016] Beneficial effects of this device:

[0017] The overall structure of the furnace adopts a square box structure, with furnace tubes and electric heating tubes staggered horizontally and vertically inside, maximizing the use of the furnace space. It is low-carbon and environmentally friendly, highly safe, highly intelligent, easy to adjust, quick to start, and has high thermal efficiency of approximately 98%, far higher than traditional gas heating furnaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a vertical cross-sectional view of the device;

[0019] Figure 2 It is a side sectional view of the device;

[0020] Figure 3 is a horizontal cross-sectional view of the device;

[0021] Figure 4 It is a partial enlarged view I of the device;

[0022] In the figure: 1 explosion-proof junction box; 2 electric heating tube; 3 medium inlet; 4 steel structure; 5 furnace wall panel; 6 thermal insulation lining; 7 furnace tube; 8 medium outlet; 9 flange cover; 10 flange; 11 casing; 12 temperature measuring element; 13 control line inlet;

[0023] 14 Power inlet. DETAILED DESCRIPTION

[0024] The specific embodiments of the device are further described in detail below in conjunction with the technical solutions and drawings.

[0025] A square-box radiant electric heating furnace. The furnace consists of, from the outside to the inside, a steel structure 4, furnace wall panels 5, and an insulating lining 6. The steel structure 4 provides support for the entire furnace. The exterior of the furnace wall panels 5 are welded to the steel structure 4, and the interior of the furnace wall panels 5 are connected to the insulating lining 6 via insulation nails. The insulating lining 6 effectively reduces heat loss and improves the thermal efficiency of the equipment.

[0026] The medium inlet 3 is located at the upper part of the furnace body, and the medium outlets 8 are located at the lower part of the furnace body. The furnace tubes 7 are arranged horizontally in the inner cavity of the square box furnace. The medium flows from top to bottom along each row of furnace tubes 7. A certain space is left every three or more rows of furnace tubes 7 from top to bottom to insert the electric heating tube 2. The electric heating tube 2 and the furnace tube 7 are arranged at 180 degrees to each other. The furnace tubes 7 are arranged in multiple rows in the horizontal direction, and the spacing between each row is 1.5 times the tube center distance or multiple times the tube center distance. The furnace tubes 7 are distributed throughout the entire inner cavity of the square box furnace. According to the heating requirements of the process medium, each row of furnace tubes 7 can be one tube pass or multiple rows of furnace tubes 7 can be one tube pass.

[0027] The electric heating tube 2 is inserted into the furnace cavity from the side (from one side for small furnaces and from both sides for large furnaces). This provides heat to the furnace. A flanged sleeve 11 is installed on the side of the furnace, connecting it to the furnace cavity. The electric heating tube 2 passes through the sleeve 11 and enters the furnace. A flange cap 2 at the end of the electric heating tube 2 is bolted to the sleeve flange 10. An explosion-proof junction box 1 is installed at the end of the electric heating tube 2. This box has a control line inlet 13 and a power line inlet 14. A temperature measuring element 12 is also installed on the electric heating tube 2.

[0028] The process medium enters the furnace through the medium inlet 3 and receives radiant heat from the furnace tube 7. When energized, the electric heating tube 2 generates heat, which is then transferred to the furnace tube 7 via radiation, heating the medium. The heated process medium then flows out through the medium outlet 8.

[0029] The control inlet 13 and power inlet 14 are connected to the electronic control system, supplying power to the electric heating tube 2 and receiving signals from instruments such as temperature and pressure. Electricity is connected to the electric heating tube 2 through the explosion-proof junction box 1, generating heat when powered. The medium enters the furnace tube 7 through the medium inlet 3, absorbing heat from the radiant heat of the electric heating tube 2. The heated medium then flows out through the outlet 8. The furnace cavity is sealed and filled with an inert protective gas, nitrogen.

Claims

1. A radiation square box electric heating furnace, characterized in that: From outside to inside, they are the square box furnace steel structure, square box furnace wall panel, and thermal insulation lining. The square box furnace steel structure is used to support the entire shell. The square box furnace steel structure is welded to the square box furnace wall panel, and a thermal insulation lining is provided on the inner side of the wall panel to play a role in thermal insulation. The furnace tubes are arranged horizontally in the inner cavity of the square box furnace. The medium flows from top to bottom along each row of furnace tubes. A certain space is left every three or more rows of furnace tubes from top to bottom to insert electric heating tubes. The electric heating tubes and the furnace tubes are arranged at 90 degrees to each other. The furnace tubes are arranged in multiple rows in the horizontal direction, and the spacing between each row is 1.5 times the tube center distance or multiple times the tube center distance. The furnace tubes are completely distributed throughout the entire square box furnace cavity. According to the heating requirements of the process medium, each row of furnace tubes can be one tube pass, or multiple rows of furnace tubes can be one tube pass. The electric heating tube is inserted into the square box furnace cavity from the side. For small square box furnaces, it is inserted from one side, and for large square box furnaces, it is inserted from both sides. The electric heating tube provides heat for the heating furnace. A flange sleeve is provided on the side of the square box furnace, which is connected to the furnace chamber. The electric heating tube passes through the sleeve and enters the furnace body. The flange cover at the end of the electric heating tube is bolted to the sleeve flange. An explosion-proof junction box is provided at the end of the electric heating tube, which has a control line inlet and a power line inlet. A temperature measuring element is provided on the electric heating tube. The entire electric radiation square box furnace is a fully enclosed structure, filled with nitrogen inert protective gas to protect the electric heating tube from oxidation; the square box furnace is equipped with an inert gas supplement system, which automatically replenishes inert gas when the pressure in the furnace cavity decreases.

2. The radiation square box electric heating furnace according to claim 1, characterized in that: The inner core of the electric heating tube is a heating resistance wire, and the casing is made of high alloy steel or a suitable material selected according to the characteristics of the heating medium and the operating temperature. Magnesium oxide powder is filled between the resistance wire and the casing for insulation treatment to ensure the safe and reliable operation of the electric heating tube.

3. The radiation square box electric heating furnace according to claim 1, characterized in that: The electric heating tube is equipped with a temperature measuring element and an over-temperature interlock protection system. When the temperature exceeds the set temperature, the system will automatically stop heating to prevent the equipment from overheating and damage. At the same time, temperature measuring elements are set at the inlet and outlet of the medium. By monitoring the inlet and outlet temperatures in real time, the power of the heating tube is adjusted to achieve precise temperature control and meet the process requirements with high temperature control requirements.

4. The radiation square box electric heating furnace according to claim 1, characterized in that: The protective gas in the shell can be other inert protective gases besides nitrogen.

5. The radiation square box electric heating furnace according to claim 1, characterized in that: The furnace tubes are protected by various arrangements such as horizontal coils and vertical coils to meet the heating needs of different process media and equipment space layout requirements.

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