CN101403529B - air rapid heater - Google Patents

Abstract

The invention discloses a quick air heater, mechanical parts thereof adopt waterproof and high-temperature resistant materials, and a core heating part adopts electrothermal film heating pipes, thus achieving ultrahigh electrothermal transfer efficiency which is over 95 percent and ultra-quick response; the electrothermal film heating pipes are distributed in the form of an isoperimetric polygon, thus ensuring even air heating; the quick air heater takes the shape of a cylinder with two thinner ends and a thicker middle part integrally and consists of three parts which are an expanding section, a heating section and a shrinking section, the expanding section and the shrinking section are approximately completely symmetric relative to the midline of the heating section in structure; the design that the whole quick air heater is divided into three sections takes consideration that the electrothermal film heating pipes and adapter sleeves thereof need to be placed in the heating section and both parts occupy certain cross section areas. In order to reduce pressure reduction loss and optimally keep flow speed unchanged in a process that airflow passes through the heater, the core heating part of the heating section adopts the ultra-thin electrothermal film heating pipes, the axial direction of which is the same as the airflow direction, and the effective cross section area of high wet air that passes through the heating section is ensured to be approximately the same as the cross section area of the original pipe.

Description

air rapid heater

1. Technical field

The invention relates to a rapid air heater, which is suitable for a wide range of air humidity (5%RH-100%RH), and has less pressure loss during the heating process.

2. Background technology

The temperature, humidity and pressure comprehensive measurement and verification device is specially designed to provide a uniform temperature and humidity environment under a certain pressure. This uniform temperature and pressure environment is obtained by transforming the saturated moisture generated by the previous device through the principle of double temperature and double pressure. On the premise of ensuring the uniformity of the temperature and humidity field, it is a routine requirement for the verification test to rapidly increase the gas state from low temperature to high temperature. Therefore, it is necessary to properly rectify, uniformly heat, and quickly heat up the saturated moisture generated by the pre-stage device under the condition of small pressure loss. There are many ways to rapidly heat the gas, but generally only for ordinary air, or do not consider the high humidity of the air or the uniformity of heating or the large loss of pressure drop.

Chinese patent (application number is: 93207418.9) has introduced a kind of electric heating fan, and its mechanical structure is shown in Fig. 1. The electric heating fan has a casing, one end of the casing is provided with an air outlet 22 with a heating sheet inside, and a multi-wing fan driven by a motor is arranged inside the casing, the axial direction of the multi-wing fan intersects with the heating sheet at 90°, and the rotation of the multi-wing fan produces The hot wind is sent out from the air outlet through the electric heater to form hot air. This method of heating air with an electric heating fan is commonly used in conventional air heaters: that is, the airflow is blown vertically onto the heating element. This method improves the heat exchange efficiency to a certain extent, and the structure is relatively simple. However, its shortcomings are also quite obvious: first: the airflow is blown vertically to the heating part, and then discharged through the air outlet, the pressure loss is obviously too large; second: the temperature of the exhaust airflow is uneven; third, the heating part is a traditional heating part, The heat transfer efficiency of electric heating is not high, and the thermal inertia is large.

Chinese patent (Application No.: 200710056905.0) introduces an air heater, in which a cylindrical shell 2 is covered with a ceramic or metal inner cylinder 4, and a porous ceramic foam material is filled between the inner cylinder 4 and the heating element 6 therein. 5. The heating element is electric heating wire, electric heating rod, silicon carbon tube, etc. The advantage of this type of heater is that it heats evenly and has a large surface area. However, shortcomings and deficiencies are also obvious. First, the heating elements use traditional materials such as heating wires and heating rods. This kind of material is easy to age, easy to oxidize, has low electrothermal conversion efficiency, and slow temperature rise, which is not conducive to rapid temperature rise. Second: Although the porous ceramic foam material has increased porosity compared with ordinary foam materials, the pressure drop loss is obviously still very large. Third: Foam materials generally have serious water absorption and cannot meet the heating requirements of high-humidity gas.

3. Contents of the invention

The present invention is an air rapid heater, and its purpose is to solve the problem of rapid heating for the air with a wide humidity range (5%RH～100%RH) for the deficiencies of the prior art in terms of heating speed, efficiency and pressure loss resistance , and ensure that the air is evenly heated and the pressure loss is small when it flows through the heating device.

The present invention is a rapid air heater, whose mechanical parts are generally made of waterproof and high-temperature-resistant materials, and the core heating part is made of an electrothermal film heating tube. The electrothermal conversion efficiency is extremely high, above 95%, and the response is extremely fast. The distribution of the electrothermal film heating tubes is equi-polygonal to ensure uniform heating of the air.

The air rapid heater is generally in the shape of a cylinder with thinner ends and a thicker middle. It consists of three parts: a flared section, a heating section, and a closed section. Structurally, the flared section and the closed section are almost completely symmetrical. The whole is divided into three sections mainly because the heating section needs to install the electrothermal film heating tube and its fastening sleeve, both of which will occupy a certain cross-sectional area. In order to reduce the pressure drop loss during the air flow through the heater and keep the flow velocity as constant as possible, the core heating part of the heating section adopts an ultra-thin electrothermal film heating tube, whose axial direction is the same as the air flow direction, and ensures The effective cross-sectional area of the high-humidity air flowing through the heating section is roughly equivalent to the cross-sectional area of the original pipe. The material used for the shell of the device must be able to withstand -60°C to 500°C, and have the characteristics of non-absorbent, easy to machine, durable and so on. The lining pipe in the heating section must be able to withstand -60°C to 700°C, not absorb water, and have good insulation and thermal conductivity. The lining pipes in the flaring section and the closing section must be able to withstand -60°C to 250°C, not absorb water, be easy to machine, and have good insulation properties. Excellent thermal insulation material should be used between the liner pipe and the outer shell, and it needs to withstand a temperature of 700°C, and the thermal conductivity at room temperature should be less than 0.05W/m·K. The flared section, the heating section, and the closed section are sealed and connected by sealing rings and flanges. When the pressure difference between the inside and outside of the heater is ±130KPa, the air leakage rate at the flange connection is ≤1×10 ^-5 cm ³ /s.

Wherein, the housing of the device can be made of low-temperature resistant iron pipe, steel pipe, copper pipe, etc. The lining pipe of the heating section can be a ceramic pipe or the like. The lining pipes of the flaring section and the closing section can use PTFE tubes, etc. The heat insulation layer can be made of ceramic fiber paper and the like. O-type PTFE rings can be used for sealing rings, butt welding flanges and flat welding flanges can be used for flanges, and convex or flat surfaces can be used for sealing surfaces.

The entire flaring section is composed of sensor fixing rods, sensor brackets, diversion pipes, air rectification nets, inner liner pipes, heat insulation layers, and shells from the inside to the outside. The temperature sensor is placed on one end of the sensor fixing rod where the air flows in, and the other end is fixed on the sensor bracket. The sensor bracket can accommodate multiple sensor fixing rods and fix them side by side along the direction perpendicular to the airflow, so as to monitor the temperature at different positions and detect the temperature uniformity. The sensor bracket is welded to the inside of the draft tube next to the threaded counterbore. The length of the air flow into one end of the guide tube exceeds the liner pipe and almost touches the trumpet-shaped shell of the flaring section, and the air flow out of the guide tube fixes the air rectifying net at one end. In the flaring section, the sensor fixing rod, the sensor bracket, the guide pipe and the air rectifying net are integrated. The material used for the lining pipe needs to have three properties. One is insulation to avoid the danger of 220v alternating current in case of accident. Second, fix the guide tube. The inner liner is easy to machine, and several threaded counterbores are designed on the gas inflow side to fix the draft tube. Third, heat insulation needs to have a certain heat insulation performance. Considering the safety and energy saving of the heater, the thermal insulation layer must be made of thermal insulation material with excellent high temperature resistance and strong hydrophobicity. If it has water absorption, high temperature waterproof glue must be applied to the part of the material exposed to the air. A through hole is designed in the middle part of the flaring section, and a transfer platform is welded on the hole, and the transfer platform is used together with the sealed socket. The power line and signal line of the temperature sensor and the power line of the electric heating film heating tube are introduced/extracted through the sealed socket. When the pressure difference between the inside and outside of the heater is ±130KPa, the overall air leakage rate of the transfer platform and the sealed socket is ≤1×10 ^-5 cm ³ /s.

The heating section is composed of electrothermal film heating tube, metal disc, lining tube, heat insulation layer, shell and other parts from inside to outside. The metal disc is machined with 3n(n-1)+1 holes by wire cutting, where n is a positive integer. The distribution of the holes is as follows: a hole in the center of the disc is the first layer, there are 6 holes in the second layer around the center hole, 12 holes in the third layer, and 6(n-1) holes in the nth layer. The line connecting the centers of the circles formed by the 6 (k-1) holes in the kth (2≤k≤n) layer is a first-class hexagon, and the center of the inscribed circle of the hexagon is the same as the center of the circle formed by the central hole ). Any one through hole in the Mth (1≤M≤n-1) layer and two adjacent holes in the m+1 layer, and the lines connecting the centers of the circles formed by each of the three holes are basically equilateral triangles. The through holes are connected by metal ribs, and the redundant parts are all cut off. A number of through holes are designed in the middle of the lining pipe, and two metal discs are fixed on the inner wall of the lining pipe through hook-shaped fixing rods (the hooks are inserted into the through holes). On the one hand, the inner liner plays the role of insulating and fixing the metal disc, separating the metal disc from the shell and fixing it on the inner wall. On the other hand, the heat conduction effect of the lining pipe is excellent, and the temperature of its inner wall is close to that of the metal disc, so that an approximate uniform temperature field will be formed inside the entire lining pipe, which is beneficial to temperature control. A number of gaps are left at both ends of the lining pipe, and the fixing columns are welded on the shell at the positions of the gaps, so as to fix the lining pipe. Considering the safety and energy saving of the heater, the thermal insulation layer must be made of thermal insulation material with excellent high temperature resistance and strong hydrophobicity. If it has water absorption, high temperature waterproof glue must be applied to the part of the material exposed to the air.

After the closing section shrinks the pipe diameter properly, the gas flows through the lined pipe. Considering that the gas is further mixed during the process of flowing through the liner, the temperature will be more uniform. Therefore, a rectification net is installed on the gas inflow side of the closing section, and a temperature sensor is installed on the outflow side for temperature feedback. The entire closure section is composed of sensor fixing rods, sensor brackets, diversion pipes, air rectification nets, inner liner pipes, heat insulation layers, and shells from the inside to the outside. The temperature sensor is placed on one end of the sensor fixing rod where the air flows out, and the other end is fixed on the sensor bracket. The sensor bracket can accommodate multiple sensor fixing rods and fix them side by side along the direction perpendicular to the airflow, so as to monitor the temperature at different positions and detect the temperature uniformity. The sensor bracket is welded to the inside of the draft tube next to the threaded counterbore. The length of the air outlet end of the draft tube exceeds the inner liner and almost touches the trumpet-shaped shell of the closing section. In the closing section, the sensor fixing rod, the sensor bracket and the guide tube are integrated, and the three are separated from the air rectifying net. The material used for the lining pipe needs to have three properties. One is insulation to avoid the danger of 220v alternating current in case of accident. Second, fix the air rectifying net and guide tube. The liner pipe is easy to machine, and a number of threaded countersunk holes are designed on the gas inflow side to fix the air rectifying net; a number of threaded countersunk holes are designed on the gas outflow side to fix the guide tube. Third, heat insulation needs to have a certain heat insulation performance. Considering the safety and energy saving of the heater, the thermal insulation layer must be made of thermal insulation material with excellent high temperature resistance and strong hydrophobicity. If it has water absorption, high temperature waterproof glue must be applied to the part of the material exposed to the air. A through hole is designed in the middle of the closing section, and a transfer platform is welded on the hole, and the transfer platform is used together with the sealed socket. The power line and signal line of the temperature sensor and the power line of the electric heating film heating tube are introduced/extracted through the sealed socket. When the pressure difference between the inside and outside of the heater is ±130KPa, the overall air leakage rate of the transfer platform and the sealed socket is ≤1×10 ^-5 cm ³ /s.

Wherein, the shell of the rapid air heater adopts a low temperature resistant metal tube.

Wherein, the lining pipe of the heating section of the rapid air heater adopts a ceramic pipe.

Wherein, the lining pipes of the flaring section and closing section of the rapid air heater adopt tetrafluoro tubes.

Wherein, the thermal insulation layer of the rapid air heater adopts ceramic fiber paper, and the part exposed to the air is coated with high-temperature waterproof glue.

Wherein, the sealing connection device of the rapid air heater adopts a sealing ring, and the sealing surface is a convex surface.

Wherein, the sealing connection device of the rapid air heater adopts a sealing ring, and the sealing surface is a plane.

Wherein, the sealing ring adopts O-type PTFE ring.

Wherein, the sealing connection device of the rapid air heater adopts a butt welding flange.

Wherein, the sealing connection device of the rapid air heater adopts a flat welding flange.

A kind of rapid air heater of the present invention, its characteristic and superiority are:

1. The core heating part adopts electric heating film heating tube. Electric film heating tube is highly efficient and energy-saving: large heat exchange area, high electrothermal conversion efficiency, up to 95% or more; fast heating speed, rapid temperature rise, reaching thermal balance in one minute; easy temperature control: synchronous heating, small thermal inertia, uniform thermal field, Easy and precise temperature control.

2. The heater adopts a 3-stage design. The effective flow area of the air at the entrance of the flaring section, the heating section, and the exit of the closing section is roughly the same. The airflow velocity is stable. The axial direction of the heating tube is the same as the airflow direction, and the pressure drop loss is small.

3. The thermal field is uniform. The core heating part of the heating section is composed of 3n(n-1)+1 electrothermal film heating tubes. An electrothermal film heating tube is located in the very center, and several layers of electrothermal film heating tubes are distributed around the central tube in an equihexagonal shape. Any through hole in the mth (1≤m≤n-1) layer is connected to the m+1 layer Two adjacent holes, the circle centers of the circles formed by the three holes are basically equilateral triangles. The electrothermal film heating tube is fixed inside the lined pipe by a metal disc. The selected metal disc and the lined tube are made of very good heat conductors, so that an almost uniform temperature field is formed inside the entire lined tube.

4. The heater has a strong ability to resist high humidity. The parts of the entire heater should be made of non-absorbent materials as much as possible. For materials with water absorption, apply high-temperature waterproof glue to all parts directly in contact with the air. Therefore, it can heat the air with humidity ranging from 5%RH to 95%RH.

5. The heater has good airtightness and can quickly heat the gas of 300Pa~130000Pa. The three sections are sealed and connected by sealing rings and flanges; the flared section and the closed section are equipped with sealed sockets to lead/introduce the sensor signal line and power line. The above measures ensure good airtightness when the low-pressure air is rapidly heated .

4. Description of drawings

Fig. 1 is a schematic diagram of the structure of an improved electric heating fan in the background technology.

Fig. 2 is a schematic structural diagram of an air heater in the background technology.

Fig. 3 is an axial sectional view of an air heater in the background technology.

Fig. 4 is a schematic structural diagram of an air heater according to a specific embodiment of the present invention.

Fig. 5 is a schematic cross-sectional view of a heating section of an air heater according to a specific embodiment of the present invention.

Fig. 6 is a schematic view of the direction of air flow according to a specific embodiment of the present invention.

Fig. 7 is a schematic diagram of a ceramic tube according to a specific embodiment of the present invention.

Fig. 8 is a schematic diagram of a tetrafluoro tube according to a specific embodiment of the present invention.

Fig. 9 is a schematic diagram of a copper disk according to a specific embodiment of the present invention.

Fig. 10 is a schematic diagram of a sensor bracket according to a specific embodiment of the present invention.

The labels and symbols in the figure are explained as follows:

1-Intake pipe 2-Cylinder shell 3-Insulation material

4-Metal inner cylinder 5-Porous foam ceramic material 6-Electric heating element

7-Thermostat 8-Outlet pipe 9-External wire

10-Sensor 11-Sensor fixing rod 12-Sensor bracket

13-Rectification network 14-Drain tube 15-PTFE tube

16-ceramic fiber layer 17-steel pipe 18-transfer platform

19-Sealed socket 20-High temperature waterproof glue, 21-Electric film heating tube

22-ceramic tube 23-copper plate, 24-airflow direction

25-Multi-blade fan 26-Electric heater 27-Safety power-off device

28-Air outlet 29-Blade 30-Ring

31-Temperature control switch 32 Gap for fixing the ceramic tube 33 Through hole for fixing the copper plate

34-Counter hole for fixing the diversion tube 35-Through hole for installing the transfer platform 36-Through hole for installing the electric heating film heating tube

37-Copper bar 38-Copper ring 39-Through hole

40-flange 1 41 flange 2 42 copper plate

5. Specific implementation methods:

Referring to Fig. 4, the present embodiment is a rapid air heater with a wide humidity range. The left dotted line on the left is the flaring section, the right dotted line on the right is the closing section, and the middle of the two dotted lines is the heating section. The air flow direction is shown in Figure 6. The flared section, the heating section, and the closing section are sealed and connected by a sealing ring and flange 41 (the specification is DN125-PN10 RF (series II) GB/T9119-2000). When the pressure difference between the inside and outside of the heater is ±130KPa, The air leakage rate at the joint of the flange 41 is ≤1×10 ^-6 cm ³ /s. The steel pipe used for the shell of the device is a low temperature resistant non-brittle nickel steel pipe containing more than 3.5% Ni. The inner liner of the heating section adopts ceramic tube 15, and the inner liner of the flaring section and the closing section adopts 250°C high-quality polytetrafluoroethylene material (hereinafter referred to as the PTFE tube) 15 . The thermal insulation layer adopts the ceramic fiber layer 16. Metal disc adopts copper disc 23. The sealed socket adopts an environment-resistant circular connector 19, with a temperature resistance of -60°C to 260°C, and when the pressure difference is ±130KPa, the air leakage rate is less than 1×10 ^-5 cm ³ /s.

The entire flaring section is sequentially arranged from the inside to the outside, as shown in Figure 8, the sensor fixing 11, the sensor bracket 12, the guide tube 14, the air rectifying net 13, the tetrafluoro tube 15, the ceramic fiber layer 16, the round steel tube 17 and other parts constitute. The temperature sensor is placed on one end of the sensor fixing rod 11 where the air flows in, and the other end is fixed on the sensor bracket. The sensor bracket 12 can accommodate a plurality of sensor fixing rods 11 fixed side by side along the direction perpendicular to the airflow, so as to monitor the temperature at different positions and detect the temperature uniformity. The sensor bracket 12 is welded on the inner side of the draft tube 14 next to the threaded counterbore 34 . The length of air flowing into one end of the guide tube exceeds the trumpet-shaped shell of the teflon tube 15 and almost contacts the closing section, and the air of the guide tube 14 flows out of one end to fix the air rectifying net 13 . In the flaring section, the sensor fixing rod 11, the sensor bracket 12, the guide pipe 14, and the air rectifying net 13 are integrated. Lined PTFE tube 15 mainly has three functions. One is insulation to avoid the danger of 220v alternating current in case of accident. Second, the gas guide tube 14 is fixed. The PTFE tube is easy to machine, and four threaded counterbores 34 are designed on its gas inflow side to fix the draft tube. Third, heat insulation, the PTFE tube 15 has a certain heat insulation performance. The ceramic fiber layer 16 has very good high-temperature heat insulation performance, and is a widely used heat insulation material. A 1cm thick ceramic fiber layer 16 is wound on the outer wall of the PTFE tube to fully exert its heat insulation effect. However, ceramic fiber paper has a water-absorbing defect, so it is necessary to coat high-temperature, heat-insulating, insulating, and waterproof glue 20 on both sides. The high-temperature glue 20 solves the water absorption problem of the ceramic fiber paper on the one hand, and on the other hand fills up the gaps, so that the gas can only flow through the main road—the PTFE tube 15. A through hole 34 is designed in the middle of the flaring section, and a transfer platform is welded on this hole. The transfer platform 18 is used together with the sealing socket 19. The sealing socket 19 can withstand temperature from -60°C to 260°C and the pressure difference is ±130KPa. , Air leakage rate <1×10 ^-5 cm ³ /s. The power line and signal line of the temperature sensor 10 and the power line of the electrothermal film heating tube 21 are introduced/extracted through the sealed socket.

The heating section is composed of electrothermal film heating tube 21, copper plate 23, ceramic tube 22, ceramic fiber layer 16, steel pipe 17 and other parts from inside to outside. The copper plate 23 is processed with 7 holes 36 (see FIG. 9 ) by wire cutting. The distribution of the holes is as follows: a hole in the center of the copper plate, and 6 holes around the central hole. The center of the circle formed by these 6 holes is The connection line is a first-class hexagon (the center of the inscribed circle of the hexagon is the same as the center of the circle formed by the central hole), and any two adjacent holes in the 6 holes are connected to the centers of the circles formed by the central hole. The lines are basically equilateral triangles. The through holes are connected with each other by copper ribs 37, and the redundant parts are all cut off. There are respectively 4 through holes 33 at the two ends of the ceramic tube at 50 cm, and the two copper plates are fixed on the inner wall of the ceramic tube by hook-shaped fixing rods (the hooks are inserted into the through holes). The ceramic tube 22 plays the role of insulating and fixing the copper plate 23 on the one hand, separates the copper plate 23 from the steel pipe 17 and fixes the copper plate therein. On the other hand, the ceramic tube 22 has excellent heat conduction effect, and the temperature of the inner wall is close to that of the copper plate 23, so that an approximately uniform temperature field will be formed inside the entire ceramic tube 22, which is beneficial to temperature control. Four gaps 32 are left at both ends of the ceramic tube, and the fixing columns are welded on the steel pipe at the positions of the gaps 32, so that the ceramic tube 22 is fixed. The ceramic fiber layer 16 is a thermal insulation material of a good grade, and the ceramic fiber paper with a thickness of 1 cm is wound on the outer wall of the ceramic tube to bring into play its performance. However, ceramic fiber paper has water absorption defects, so it is necessary to coat high-temperature, heat-insulating, insulating, and waterproof glue 20 on both sides. The high-temperature glue 20 solves the water absorption problem of the ceramic fiber layer 16 on the one hand, and fills up the gaps on the other hand, so that the gas can only flow through the main road---ceramic pipe 22.

After the diameter of the pipe is appropriately shrunk by the closing section, the gas flows through the lined PTFE pipe 15 . Considering that the gas is further mixed during the process of flowing through the PTFE tube, the temperature will be more uniform, so a rectifier 13 is installed on the gas inflow side of the closing section, and a temperature sensor 10 is installed on the outflow side for temperature feedback. The whole closing section is sequentially composed of sensor fixing rod 11, sensor bracket 12, guide tube 14, air rectifying net 13, tetrafluoro tube 15, ceramic fiber layer 16, steel pipe 17 and other parts from inside to outside. The temperature sensor 10 is placed at one end of the air outflow of the sensor fixing rod, and the other end is fixed on the sensor bracket 12 . The sensor bracket can accommodate a plurality of sensor fixing rods 11 fixed side by side along the direction perpendicular to the airflow, so as to monitor the temperature at different positions and detect the temperature uniformity. The sensor bracket 12 is welded on the inner side of the draft tube 14 next to the threaded counterbore 34 . The length of the air flow out of one end of the draft tube 14 exceeds the trumpet-shaped casing (seeing figure 4) of the teflon tube that almost contacts the closing section. The sensor fixed rod 11, the sensor bracket 12, and the guide tube 14 are integrated at the closing section, and the three are separated from the air rectifying net 13. Lined PTFE tube 15 mainly has three functions. One is insulation to avoid the danger of 220v alternating current in case of accident. Its two, fixed air rectifying net 13, guide pipe 14. The PTFE tube is easy to be machined, and four threaded counterbores 34 are designed on its gas inflow side to fix the air rectifying net; Third, heat insulation, the PTFE tube 15 has a certain heat insulation performance. The ceramic fiber layer 16 is a thermal insulation material of a good grade, and a 1cm thick ceramic fiber layer 16 is wound on the outer wall of the tetrafluoro tube 15 to bring into play its performance. However, the ceramic fiber layer 16 has water-absorbing defects, so it is necessary to coat high-temperature, heat-insulating, insulating, and waterproof glue 20 on both sides. The high-temperature glue 20 solves the water absorption problem of the ceramic fiber layer 16 on the one hand, and fills up the gap on the other hand, so that the gas can only flow through the main road---the PTFE tube 15. A through hole 35 is designed in the middle of the flaring section, and a transfer platform 18 is welded on this hole. The transfer platform 18 is used together with the sealing socket 19. The sealing socket 18 can withstand temperature from -60°C to 260°C, and the pressure difference is ±130KPa , the air leakage rate is <1×10 ^-5 cm ³ /s. The power line and signal line of the temperature sensor 10 and the power line of the electrothermal film heating tube 21 are introduced/extracted through the sealed socket. With the help of the temperature sensors 10 at the front and rear ends of the heater, the closed-loop control of rapid heating of the air can be realized.

Claims (10)

1. A rapid air heater, characterized in that: the rapid air heater is generally in the shape of a cylinder that is slightly thinner at both ends and slightly thicker in the middle, and is composed of three parts: a flared section, a heating section, and a closed section. Structurally, the flaring section and the closing section are almost completely symmetrical with respect to the center line of the heating section; the three sections of the flared section, the heating section, and the closing section are sealed and connected by sealing rings and flanges; ℃, and has the characteristics of non-water absorption, easy machining, and durability. The lining pipe in the heating section must be able to withstand -60 ℃ ~ 700 ℃, non-absorbent, and have good insulation and thermal conductivity; in the flared section and the closed section The liner must be resistant to -60°C to 250°C, non-absorbent, easy to machine, and have good insulation properties; the heat insulation layer between the liner and the shell is made of excellent heat insulation material. It has the characteristics of high temperature resistance of 700°C and thermal conductivity of less than 0.05W/m·K at room temperature; when the pressure difference between the inside and outside of the heater is ±130KPa, the air leakage rate at the flange connection is ≤1×10 ^-5 cm ³ /s; The entire flaring section is composed of sensor fixing rods, sensor brackets, diversion pipes, air rectification nets, lining pipes, heat insulation layers, and shells from the inside to the outside; the sensor fixing rods place temperature sensors at one end of the air inflow, and the other end It is fixed on the sensor bracket; the sensor bracket accommodates a predetermined number of sensor fixing rods and is fixed side by side along the direction perpendicular to the air flow; the sensor bracket is welded on the inner side of the guide tube next to the threaded counterbore; the length of the air inflow end of the guide tube exceeds almost The trumpet-shaped shell that contacts the flaring section, the air flow out end of the diversion tube is fixed with the air rectifying net; the sensor fixing rod, the sensor bracket, the diversion tube, and the air rectifying net are integrated in the flaring section; the inner lining tube fixes the diversion tube, A threaded counterbore is designed on the gas inflow side to fix the diversion tube; a through hole is designed in the middle of the flared section, and a transfer platform is welded on this hole, and the transfer platform is used together with the sealed socket; the temperature sensor The power line, signal line, and power line of the electric heating film heating tube are introduced/exported through the sealed socket; when the pressure difference between the inside and outside of the heater is ±130KPa, the overall air leakage rate of the transfer platform and the sealed socket is ≤1×10 ^-5 cm ³ / s; The heating section is composed of electrothermal film heating tube, metal disc, lining tube, heat insulation layer and shell from inside to outside; the metal disc is processed with 3n(n-1)+1 holes by wire cutting, n It is a positive integer; the distribution of holes is as follows: a hole in the center of the disk is the first layer, there are 6 holes in the second layer around the center hole, 12 holes in the third layer, and 6(n-1) in the nth layer holes; the line connecting the centers of the circles formed by the 6 (k-1) holes in the kth layer is a first-class hexagon and the center of the inscribed circle of this hexagon is the same as the center of the circle formed by the central hole, where 2≤ k≤n; Any one through hole in the Mth layer and two adjacent holes in the m+1 layer, where 1≤M≤n-1, the connecting line of the circle centers formed by the three holes is an equilateral triangle; through The hole and the through hole are connected by metal ribs, and the excess parts are cut off; a through hole is designed in the middle of the lining pipe, and two metal discs are fixed on the inner wall of the lining pipe through a hook-shaped fixing rod; the lining pipe will The metal disc and the shell tube are separated and fixed on the inner wall of the shell tube; gaps are left at both ends of the liner tube, and the fixing column is welded to the shell at the position of the gap to fix the liner tube; After the closing section shrinks the diameter of the pipe properly, the gas flows through the lining pipe; a rectification net is installed on the side where the gas flows into the closing section, and a temperature sensor is installed on the outflow side for temperature feedback; the entire closing section is sequentially fixed by the sensor from the inside to the outside. , sensor bracket, diversion pipe, air rectifying net, inner liner, heat insulation layer, and shell; the sensor fixing rod places a temperature sensor at one end of the air outflow, and the other end is fixed on the sensor bracket; the sensor bracket accommodates a predetermined number of sensors to fix The rods are fixed side by side perpendicular to the airflow direction; the sensor bracket is welded on the inner side of the diversion tube next to the threaded counterbore; the length of the air outlet end of the diversion tube exceeds the liner tube and almost touches the horn-shaped shell of the closing section; the sensor is fixed at the closing section The rod, the sensor bracket, and the diversion tube are integrated, and the three are separated from the air rectification net; the inner liner tube fixes the air rectifier net and the diversion tube; the inner liner tube is easy to machine, and the predetermined thread is designed on the gas inflow side Counterbore to fix the air rectifying net; a threaded counterbore is designed on the gas outflow side to fix the diversion tube; a through hole is designed in the middle of the closing section, and a transfer platform is welded on this hole, and the transfer platform and The sealed socket is used together; the power line, signal line of the temperature sensor, and the power line of the electric heating film heating tube are introduced/extracted through the sealed socket; when the pressure difference between the inside and outside of the heater is ±130KPa, the overall air leakage rate of the transfer platform and the sealed socket is ≤1 ×10 ^-5 cm ³ /s. 2. The rapid air heater as claimed in claim 1, characterized in that: the shell of the rapid air heater adopts a low temperature resistant metal tube. 3. The rapid air heater according to claim 1, characterized in that: the lining pipe of the heating section of the rapid air heater is a ceramic tube. 4. The rapid air heater according to claim 1, characterized in that: the lining pipes of the flaring section and the closing section of the air rapid heater adopt tetrafluoro tubes. 5. The rapid air heater according to claim 1, characterized in that: the heat insulation layer of the rapid air heater is made of ceramic fiber paper, and the part exposed to the air is coated with high-temperature waterproof glue. 6. The rapid air heater according to claim 1, characterized in that: the sealing connection device of the rapid air heater adopts a sealing ring, and the sealing surface is a convex surface. the 7. The rapid air heater according to claim 1, characterized in that: the sealing connection device of the rapid air heater adopts a sealing ring, and the sealing surface is a plane. 8. The rapid air heater according to claim 7 or 8, characterized in that: the sealing ring is an O-shaped tetrafluoro ring. 9. The rapid air heater according to claim 1, characterized in that: the sealing connection device of the rapid air heater adopts a butt welding flange. 10. The rapid air heater according to claim 1, characterized in that: the sealing connection device of the rapid air heater adopts a flat welded flange. the

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