A sectional radiation heat exchange device for tunnel kiln

Abstract

The utility model provides a kind of tunnel kiln sectional type radiation heat exchange device, including main water inlet, joint, the end portion of the main water inlet is fixedly connected with joint, the joint has multiple water outlets to connect heat exchange pipe, the heat exchange pipe is multi-section backfolding, and the end portion of the heat exchange pipe is fixedly connected with another joint.The utility model has the advantages that: heat exchange pipe is sectional type, multi-section backfolding, can fully absorb radiation heat in kiln, smoke heat, heat exchange pipe outer surface is fixedly connected with sheet-shaped heat exchange plate again, heat exchange area is greatly improved, fully absorbs radiation heat in kiln and flue gas convection heat, heat exchange area is greatly improved compared with straight pipe;Several fins are fixedly connected on the bottom end both sides of heat exchange plate, and fin is linear sawtooth arrangement on the bottom end of heat exchange plate, forms turbulent disturbance, strengthens convection heat exchange, greatly improves comprehensive heat transfer coefficient, enhances the radiation absorption of heat exchange plate to high-temperature flue gas in kiln, strengthens convection heat exchange, and greatly improves comprehensive heat transfer efficiency.

Description

Technical Field

[0001] This utility model relates to the field of tunnel kiln technology, and in particular to a segmented radiant heat exchange device for tunnel kilns. Background Technology

[0002] Tunnel kilns, widely used in industries such as ceramics, refractory materials, and building materials, are characterized by a continuous high-temperature sintering process where materials move slowly within the kiln to complete preheating, firing, and cooling. In the firing zone, materials need to be maintained at a specific high temperature (typically 1200℃~1600℃) for a certain period to achieve the desired physicochemical changes. This high-temperature environment contains enormous thermal energy, but due to limitations in heat transfer efficiency and the complex airflow within the kiln, the uniformity of the temperature field distribution, the utilization rate of waste heat from flue gas, and energy consumption efficiency remain the core challenges in the design and operation of tunnel kilns.

[0003] To improve the thermal efficiency and reduce energy consumption of tunnel kilns, it is crucial to rationally recover and utilize the waste heat from the high-temperature flue gas within the kiln. Radiative heat transfer is one of the main heat transfer methods in high-temperature environments. Currently, commonly used waste heat recovery heat exchange devices in tunnel kilns mainly include: internal heat exchangers (such as straight-tube and serpentine tube types). These heat exchangers are typically installed on the kiln walls, kiln roof, or bottom of the kiln car in the firing or cooling zone of the tunnel kiln. Their working principle is to utilize the high-temperature radiant heat and convective heat of the high-temperature flue gas within the kiln to heat the cold medium flowing within the heat exchanger (such as water, heat transfer oil, or air). The recovered heat is then used to preheat combustion air, dry the green body, or produce domestic hot water.

[0004] However, existing internal heat exchangers generally suffer from the following significant shortcomings:

[0005] Limited heat exchange area: Traditional straight pipe or simple serpentine pipe designs offer a relatively small effective heat exchange surface area within limited installation space, making it difficult to fully absorb the intense radiant heat energy and convective heat energy of the flue gas inside the kiln. This limits the heat exchange capacity of a single pipe, resulting in unsatisfactory overall waste heat recovery efficiency.

[0006] Low convective heat transfer efficiency: The flow velocity of high-temperature flue gas around the heat exchanger is usually low and unevenly distributed, resulting in a low convective heat transfer coefficient between the flue gas and the smooth tube wall. Existing heat exchanger structures are unable to effectively disturb the laminar flow layer of flue gas, leading to poor convective heat transfer enhancement.

[0007] Therefore, a segmented radiant heat exchanger for tunnel kilns is proposed to solve the above problems. Utility Model Content

[0008] The purpose of this invention is to at least solve one of the aforementioned technical defects.

[0009] Therefore, one objective of this utility model is to propose a segmented radiant heat exchange device for a tunnel kiln to solve the problems mentioned in the background art and overcome the shortcomings of the existing technology.

[0010] To achieve the above objectives, one embodiment of the present invention provides a segmented radiant heat exchange device for a tunnel kiln, including a main water inlet and a connector. The end of the main water inlet is fixedly connected to the connector, and the connector has multiple water outlets for connecting heat exchange tubes.

[0011] The heat exchange tube is a multi-section folded type, and another connector is fixedly connected to the end of the heat exchange tube. A main water outlet is fixedly connected to one side of this connector.

[0012] A heat exchange plate is fixedly connected to the outer surface of the heat exchange tube, and the heat exchange plate is in the form of a sheet.

[0013] The heat exchange plates are fixedly connected to the front, rear, upper and lower edges, and the connecting plates position all the heat exchange plates.

[0014] Connectors are threaded through the receiving plate and heat exchange plate;

[0015] The heat exchange plate has perforated kiln-mounted bases fixedly connected to both ends of the connecting plate at the rear.

[0016] Several fins are fixedly connected to both sides of the bottom end of the heat exchange plate, and the fins are arranged in a straight serrated pattern at the bottom end of the heat exchange plate.

[0017] Preferably, in any of the above schemes, both the main inlet and the main outlet are flanges, and the heat exchange tube is made of copper.

[0018] The above technical solution is adopted: This heat exchange device is installed inside the tunnel kiln and is installed at a fixed point inside the kiln by means of a fixed seat inside the kiln and bolts.

[0019] The heat exchange medium, such as water or oil, flows through the main inlet, connector, heat exchange tube, other connector, and main outlet.

[0020] The heat exchange tubes are segmented and multi-sectioned, which can fully absorb the radiant heat and flue heat in the kiln. The outer surface of the heat exchange tubes is also fixedly connected with plate-shaped heat exchange plates, which greatly increases the heat exchange area.

[0021] Meanwhile, several fins are fixedly connected to both sides of the bottom end of the heat exchange plate. The fins are arranged in a straight serrated pattern at the bottom end of the heat exchange plate, forming turbulent flow disturbance, enhancing convective heat transfer, greatly improving the overall heat transfer coefficient, enhancing the heat exchange plate's radiation absorption of high-temperature flue gas in the kiln, and strengthening convective heat transfer.

[0022] Preferably, in any of the above schemes, the connection between the heat exchange tube and the heat exchange plate is that the tube is first embedded and then welded, and the water passages between the main outlet, the connector, the heat exchange tube, and the main inlet are connected.

[0023] The above technical solution is adopted. The structure of this device consists of: main inlet and main outlet: flange interface (DN50) made of 304 stainless steel, which are respectively connected to the input and output pipelines of cooling medium (water or oil).

[0024] The connector is a flow-diverting structure with an internal tapered guide cavity to evenly distribute the fluid from the main inlet to multiple heat exchange tubes. The connector is fixed to the heat exchange tubes by socket welding.

[0025] Heat exchange tubes: Composed of multiple sections of folded copper tubes (each 2m long, with a bending radius of 60mm), arranged in a continuous U-shape, with a total length of 10-15m. The spacing between adjacent tube sections is 20mm, and plate-like heat exchange plates are welded to the surface.

[0026] Heat exchange plate: A rectangular thin copper plate (1mm thick, 150mm × 80mm), vertically welded to the outer wall of the heat exchange tube, with gaps maintained between the plates. The edges of the heat exchange plate are positioned by connecting plates.

[0027] Connectors: M8 stainless steel long bolts and nuts are used to pass through the through holes of the connecting plate and the heat exchange plate to lock multiple heat exchange plates into an integral module.

[0028] Kiln-mounted base: Welded to both ends of the rear connecting plate of the heat exchange plate, it is a cast iron base with mounting holes (hole diameter 12mm) and fixed to the inner wall of the kiln body by bolts.

[0029] Fins: Copper serrated fins (5mm high, 8mm spacing) are welded to both sides of the bottom of the heat exchange plate and arranged in a wavy pattern along a straight line to form a turbulence generator.

[0030] Preferably, in any of the above embodiments, the heat exchange plates are made of copper, and there are gaps between the heat exchange plates.

[0031] The core design of this device is: segmented zigzag tubes to enhance radiation absorption. The multi-segmented zigzag heat exchange tubes extend the flow path of the medium, and combined with the high thermal conductivity of copper, they fully absorb the radiant heat and convective heat of the flue gas in the kiln, significantly increasing the heat exchange area compared to straight tubes.

[0032] Modular heat exchange plates and turbulent fins work synergistically to enhance efficiency. The heat exchange plates are assembled into detachable modules through connecting plates and connectors, increasing the radiative surface area. The serrated arrangement of the bottom fins induces flue gas turbulence, which greatly improves the convective heat transfer coefficient and significantly enhances the overall heat transfer efficiency.

[0033] Preferably, in any of the above solutions, the connecting component is a long bolt and a nut, wherein the long bolt is inserted into a connecting plate and several heat exchange plates, and the end of the long bolt is threadedly connected to a nut.

[0034] Preferably, in any of the above schemes, the maximum length of the fin is 5mm, and the connection between the fin and the heat exchange plate is welding.

[0035] Compared with the prior art, the advantages and beneficial effects of this utility model are as follows:

[0036] The segmented radiant heat exchanger for the tunnel kiln has segmented and multi-sectioned folded heat exchange tubes, which can fully absorb the radiant heat and flue gas heat inside the kiln. The outer surface of the heat exchange tubes is also fixedly connected with plate-shaped heat exchange plates, which greatly increases the heat exchange area and fully absorbs the radiant heat and flue gas convective heat inside the kiln. The heat exchange area is significantly increased compared to straight tubes.

[0037] Meanwhile, several fins are fixedly connected to both sides of the bottom end of the heat exchange plate. The fins are arranged in a straight serrated pattern at the bottom end of the heat exchange plate, forming turbulent disturbances, enhancing convective heat transfer, greatly improving the overall heat transfer coefficient, enhancing the radiative absorption of high-temperature flue gas in the kiln by the heat exchange plate, enhancing convective heat transfer, and greatly improving the overall heat transfer efficiency.

[0038] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0039] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0040] Figure 1 This is a first-view structural schematic diagram of the present invention;

[0041] Figure 2 This is a structural schematic diagram of the present invention from a second perspective;

[0042] Figure 3 This utility model Figure 1 Enlarged structural diagram at point A;

[0043] Figure 4 This utility model Figure 2 A magnified structural diagram at point B in the middle.

[0044] In the diagram: 1-Main inlet, 2-Connector, 3-Heat exchange tube, 4-Main outlet, 5-Heat exchange plate, 6-Connecting plate, 7-Connecting piece, 8-Kiln inner fixing seat, 9-Fin. Detailed Implementation

[0045] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0046] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0047] like Figure 1-4 As shown, this tunnel kiln segmented radiant heat exchange device includes a main water inlet 1 and a connector 2. The end of the main water inlet 1 is fixedly connected to the connector 2, and the connector 2 has multiple water outlets to connect to the heat exchange tube 3.

[0048] The heat exchange tube 3 is a multi-section folded type. Another connector 2 is fixedly connected to the end of the heat exchange tube 3. The main water outlet 4 is fixedly connected to one side of this connector 2.

[0049] A heat exchange plate 5 is fixedly connected to the outer surface of the heat exchange tube 3. The heat exchange plate 5 is plate-shaped.

[0050] The heat exchange plates 5 are fixedly connected to the front, rear, upper and lower edges and the connecting plates 6, which position all the heat exchange plates 5.

[0051] Connecting parts 7 are threaded through the heat exchange plate 5 and the connecting plate 6;

[0052] The heat exchange plate 5 has a perforated kiln fixing seat 8 fixedly connected to both ends of the connecting plate 6 at the rear.

[0053] Several fins 9 are fixedly connected to both sides of the bottom end of the heat exchange plate 5. The fins 9 are arranged in a straight serrated pattern at the bottom end of the heat exchange plate 5.

[0054] Example 1: Both the main inlet 1 and the main outlet 4 are flanges, and the heat exchange tube 3 is made of copper. This heat exchange device is installed inside the tunnel kiln and is fixed in place inside the kiln using bolts and a fixed base 8 inside the kiln.

[0055] The heat exchange medium, such as water or oil, flows through the main inlet 1, connector 2, heat exchange tube 3, another connector 2, and main outlet 4. The connection between the heat exchange tube 3 and the heat exchange plate 5 is a process of initial embedding followed by welding. The main outlet 4, connector 2, heat exchange tube 3, and main inlet 1 are interconnected by water. The heat exchange plates 5 are made of copper and have gaps between them. The connecting parts 7 consist of long bolts and nuts, with the long bolts inserting into the connecting plate 6 and several heat exchange plates 5, and the nuts threaded onto the ends of the long bolts. The maximum length of the fins 9 is 5mm, and the fins 9 are welded to the heat exchange plates 5.

[0056] Example 2: The structure of this device: Main inlet 1 and main outlet 4: They adopt flange interfaces (DN50) and are made of 304 stainless steel, respectively connecting the input and output pipelines of the cooling medium (water or oil).

[0057] Connector 2: It is a flow-diverting structure with an internal conical guide cavity to evenly distribute the fluid from the main inlet 1 to multiple heat exchange tubes 3. Connector 2 is fixed to the heat exchange tubes 3 by socket welding.

[0058] Heat exchange tube 3: Composed of multiple sections of folded copper tubes (single length 2m, bending radius 60mm), arranged continuously in a U-shape, with a total length of 10-15m. The spacing between adjacent tube sections is 20mm, and the surface is welded with plate-shaped heat exchange plates 5.

[0059] Heat exchange plate 5: A rectangular thin copper plate (1mm thick, 150mm × 80mm), vertically welded to the outer wall of heat exchange tube 3, with gaps maintained between the plates. The edges of heat exchange plate 5 are positioned by connecting plates 6.

[0060] Connector 7: Using M8 stainless steel long bolts and nuts, through the through holes of the connecting plate 6 and the heat exchange plate 5, multiple sets of heat exchange plates 5 are locked into an integral module.

[0061] Kiln fixed base 8: Welded to both ends of the rear connecting plate 6 of the heat exchange plate 5, it is a cast iron base with mounting holes (hole diameter 12mm) and fixed to the inner wall of the kiln by bolts.

[0062] Fin 9: Copper serrated fins (5mm high, 8mm spacing) are welded to both sides of the bottom end of heat exchange plate 5 and arranged in a wavy pattern along a straight line to form a turbulence generator.

[0063] Example 3: Installation process of this device: Heat exchanger tube forming and welding: The copper tube is bent into a U-shaped fold section using a hydraulic tube bending machine, and the inner wall of the bend is filled with fine sand to prevent collapse. Acid pickling removes the oxide layer of the copper tube, and the welding position of the heat exchange plate 5 is marked on the outer wall of the heat exchanger tube 3.

[0064] The heat exchange plate and fins are assembled. A copper plate is laser-cut into a heat exchange plate 5, and serrated fins 9 are punched on both sides of the bottom end. The surface is sandblasted. The heat exchange plate 5 is vertically positioned at the marked position of the heat exchange tube 3 and continuously welded using argon arc welding.

[0065] Modular locking and mounting: Install connecting plates 6 on the front and rear edges of heat exchange plate 5, align the through holes, insert M8 long bolts, and pre-tighten both ends with nuts. Weld kiln-inner mounting seats 8 to both ends of connecting plates 6, drill holes and tap M12 threads, and plate the surface with nickel for corrosion protection.

[0066] For pipeline system integration, the two ends of heat exchange tube 3 are inserted into the outlet of connector 2, with a insertion depth of 10mm, followed by circumferential welding. Sealing grooves are machined on the flange end faces of main inlet 1 and main outlet 4, and graphite gaskets are embedded. The bolt preload is 25N·m.

[0067] The working principle of this utility model is as follows:

[0068] Cooling medium circulation: Low-temperature water / oil enters from the main inlet 1, is branched off through connector 2 to each heat exchange tube 3, and flows through the zigzag pipe before converging at the main outlet 4 for output. Radiant heat absorption: The radiant heat from the high-temperature (800-1200℃) flue gas inside the kiln is absorbed by the surface of the heat exchange plate 5 and conducted to the medium inside the heat exchange tube 3. Convection enhancement: When the flue gas flows through the fins 9, the serrated structure disrupts the laminar boundary layer, forming vortices and improving convective heat transfer efficiency. Heat output: After absorbing heat, the medium's temperature rises (60-80℃), and it is transported to the waste heat boiler or thermal storage system through the main outlet 4.

[0069] Compared with the prior art, the present invention has the following advantages:

[0070] The segmented radiant heat exchanger of the tunnel kiln has a segmented and multi-sectioned folded heat exchange tube 3, which can fully absorb the radiant heat and flue gas heat inside the kiln. The outer surface of the heat exchange tube 3 is also fixedly connected with a plate-shaped heat exchange plate 5, which greatly increases the heat exchange area and fully absorbs the radiant heat and flue gas convection heat inside the kiln. The heat exchange area is significantly increased compared to the straight tube.

[0071] Meanwhile, several fins 9 are fixedly connected to both sides of the bottom end of the heat exchange plate 5. The fins 9 are arranged in a straight serrated pattern at the bottom end of the heat exchange plate 5, forming turbulent disturbance, enhancing convective heat transfer, greatly improving the overall heat transfer coefficient, enhancing the radiation absorption of high-temperature flue gas in the kiln by the heat exchange plate 5, enhancing convective heat transfer, and greatly improving the overall heat transfer efficiency.

Claims

1. A segmented radiant heat exchanger for a tunnel kiln, characterized in that, Includes a main inlet (1) and a connector (2). The end of the main inlet (1) is fixedly connected to the connector (2). The connector (2) has multiple outlets to connect to the heat exchange tube (3). The heat exchange tube (3) is a multi-section folded type. The end of the heat exchange tube (3) is fixedly connected to another connector (2). One side of this connector (2) is fixedly connected to the main outlet (4). A heat exchange plate (5) is fixedly connected to the outer surface of the heat exchange tube (3), and the heat exchange plate (5) is in the form of a sheet; The heat exchange plate (5) is fixedly connected to the front and rear, and upper and lower edges of the heat exchange plate (5), and the connecting plate (6) positions all the heat exchange plates (5); Connectors (7) are threaded through the receiving plate (6) and heat exchange plate (5); The heat exchange plate (5) has a perforated kiln fixing seat (8) fixedly connected to both ends of the connecting plate (6) at the rear. Several fins (9) are fixedly connected to both sides of the bottom end of the heat exchange plate (5). The fins (9) are arranged in a straight serrated pattern at the bottom end of the heat exchange plate (5).

2. The segmented radiant heat exchanger for a tunnel kiln as described in claim 1, characterized in that: The main inlet (1) and main outlet (4) are both flanges, and the heat exchange tube (3) is made of copper.

3. The segmented radiant heat exchanger for a tunnel kiln as described in claim 2, characterized in that: The connection between the heat exchange tube (3) and the heat exchange plate (5) is that they are first embedded and then welded. The water passages between the main outlet (4), the connector (2), the heat exchange tube (3), and the main inlet (1) are connected.

4. The segmented radiant heat exchanger for a tunnel kiln as described in claim 3, characterized in that: The heat exchange plate (5) is made of copper, and there are gaps between the heat exchange plates (5).

5. A segmented radiant heat exchanger for a tunnel kiln as described in claim 4, characterized in that: The connector (7) is specifically a long bolt and a nut, wherein the long bolt is inserted into the connecting plate (6) and several heat exchange plates (5), and the end of the long bolt is threaded to the nut.

6. The segmented radiant heat exchanger for a tunnel kiln as described in claim 5, characterized in that: The maximum length of the fin (9) is 5 mm, and the fin (9) is connected to the heat exchange plate (5) by welding.

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