CN112113202B

CN112113202B - Device for heating chromatographic plate by low-temperature hot water

Info

Publication number: CN112113202B
Application number: CN201910533078.2A
Authority: CN
Inventors: 谢强胜; 王维剑; 翟光喜; 李启艳; 张中湖; 郭春生
Original assignee: Shandong University; Shandong Institute for Food and Drug Control
Current assignee: Shandong University; Shandong Institute for Food and Drug Control
Priority date: 2019-06-19
Filing date: 2019-06-19
Publication date: 2021-10-01
Anticipated expiration: 2039-06-19
Also published as: CN112113202A

Abstract

The invention provides a device for heating a chromatographic plate by using low-temperature hot water, which comprises a water heater, wherein the water heater comprises a hot water outlet, the hot water outlet is connected with one or more heat utilization devices through a pipeline, the water is circulated back to the water heater after the heat utilization devices exchange heat, at least one heat utilization device comprises a flat tube, the upper part of the flat tube is provided with a device to be heated, and the hot water temperature of the hot water outlet is 30-40 ℃. According to the invention, hot water is arranged for heating, because the hot water can realize low-temperature heating, and the temperature and the flow of the hot water can be controlled in the heating process, the heating quality is ensured, and the stable volatilization of the chromatographic plate glue is kept and controlled.

Description

Device for heating chromatographic plate by low-temperature hot water

Technical Field

The invention relates to a hot water heating device, in particular to a steam heating device for low-temperature hot water.

Background

The heat pipe technology is a heat transfer element called a heat pipe invented by George Grover (George Grover) of national laboratory of Los Alamos (Los Alamos) in 1963, fully utilizes the heat conduction principle and the rapid heat transfer property of a phase change medium, quickly transfers the heat of a heating object to the outside of a heat source through the heat pipe, and the heat conduction capability of the heat transfer element exceeds the heat conduction capability of any known metal.

The heat pipe technology is widely applied to the industries of aerospace, military industry and the like, and since the heat pipe technology is introduced into the radiator manufacturing industry, the design idea of the traditional radiator is changed for people, the single heat radiation mode that a high-air-volume motor is used for obtaining a better heat radiation effect is avoided, the heat pipe technology is adopted for enabling the radiator to obtain a satisfactory heat exchange effect, and a new place in the heat radiation industry is opened up. At present, the heat pipe is widely applied to various heat exchange devices, including the field of nuclear power, such as the utilization of waste heat of nuclear power.

The water heater is used for generating steam and is a mechanical device for heating water into hot water by using the heat energy of fuel or other energy sources. The water heater has wide application field and is widely applied to places such as clothing factories, dry cleaning shops, restaurants, bunkers, canteens, restaurants, factories and mines, bean product factories and the like.

The phenomena of counterfeit medicines and illegal chemical medicine addition in the medicine market of China are frequent, the product quality is unstable, and the medication safety of people is seriously influenced. The further improvement of the analysis and detection technology is one of the main problems which are urgently needed to be solved at present, and the traditional technology is difficult to realize the instant and quick quality evaluation of the medicines, so that the key technology for innovating the quick inspection of foods, medicines and cosmetics is urgently needed at present. At present, common methods for rapid detection include TLC (thin layer chromatography), HPLC, LC-MS and the like, wherein the TLC method is simple to operate, low in detection cost and easy to popularize in a basic layer, but the separation efficiency is low, and false positive interference exists frequently; the HPLC method is sensitive and accurate, but the analysis period is long, and the rapid detection requirement cannot be met; the LC-MS method has strong specificity, high sensitivity and accurate qualification, but has high detection cost and is not suitable for field detection of quick detection. In addition, the method is usually used for identifying illegally added chemical drugs in a laboratory through methods such as chemical reaction, large-scale instrument detection and the like, steps are complicated, and the method cannot be applied to the field.

In the prior art, the phenomenon that food, medicine and cosmetics markets in China are fake and inferior, chemical medicines are illegally added frequently, the product quality is unstable, the illegal addition amount and components are disordered, and the health and safety of people are seriously influenced. The further improvement of the analysis and detection technology is one of the main problems which are urgently needed to be solved at present, and the traditional technology is difficult to realize the instant and quick quality evaluation of samples, so that the key technology of innovative and quick detection is urgently needed at present. At present, TLC (thin layer chromatography) is a common method for rapid detection, but the monitoring method rapidly volatilizes residual developing solvent, is beneficial to thin layer chromatography imaging, then sprays glue on a chromatography plate, needs low-temperature heating after glue spraying, volatilizes solvent in the glue, for example, about 35 ℃, and the prior art generally adopts an infrared heating method or hair drying, so that the temperature is difficult to control, and the resource waste and the efficiency are low.

The invention aims at the problems. A new hot water heating device is provided to provide constant low temperature heating.

Disclosure of Invention

Aiming at the defect of elasticity in the prior art, the invention provides a novel water heater. This ensures the low temperature heating quality.

In order to achieve the purpose, the invention adopts the following technical scheme:

the device for heating the chromatographic plate by the low-temperature hot water comprises a water heater, wherein the water heater comprises a hot water outlet, the hot water outlet is connected with one or more heat utilization devices through a pipeline, the water is circulated back to the water heater after the heat utilization devices exchange heat, the at least one heat utilization device comprises a flat tube, the upper part of the flat tube is provided with a device to be heated, and the hot water temperature of the hot water outlet is 30-40 ℃. The evaporator comprises a water tank and an electric heating device arranged in the water tank, wherein the electric heating device comprises a middle evaporation tube, a left collecting tube, a right collecting tube and tube groups, each tube group comprises a left tube group and a right tube group, the left tube group is communicated with the left collecting tube and the middle evaporation tube, the right tube group is communicated with the right collecting tube and the middle evaporation tube, so that the middle evaporation tube, the left collecting tube, the right collecting tube and the tube groups form heating fluid closed circulation, the electric heaters are arranged in the middle evaporation tube, the tube groups are multiple, each tube group comprises a plurality of arc-shaped tubes, the end parts of the adjacent arc-shaped tubes are communicated, the arc-shaped tubes form a series structure, and the end parts of the arc-shaped tubes form free ends of the arc-shaped tubes; the middle evaporation tube comprises a first tube orifice and a second tube orifice, the first tube orifice is connected with the inlet of the left tube group, the second tube orifice is connected with the inlet of the right tube group, the outlet of the left tube group is connected with the left collecting tube, and the outlet of the right tube group is connected with the right collecting tube; the first outlet and the second outlet are arranged on two opposite sides of the middle evaporation tube; a left return pipe is arranged between the left collecting pipe and the middle evaporation pipe, and a right return pipe is arranged between the right collecting pipe and the middle evaporation pipe; the heat utilization device is a thin-layer chromatography imaging and Raman spectrum acquisition instrument, the lower portion of the acquisition instrument is provided with a flat tube, the flat tube is connected with a hot water outlet, the upper portion of the flat tube is provided with a thin-layer chromatography plate placing table, and the device to be heated is a chromatography plate.

The invention has the following advantages:

1. according to the invention, hot water is arranged for heating, because the hot water can realize low-temperature heating, and the temperature and the flow of the hot water can be controlled in the heating process, the heating quality is ensured, and the stable volatilization of the chromatographic plate glue is kept and controlled.

2. The invention provides a vibrating tube bundle electric heating device with a novel structure, which increases the vibration range of a tube bundle by arranging more tube groups in a limited space, thereby strengthening heat transfer and enhancing descaling.

3. The invention can further improve the heating efficiency by arranging the pipe diameters and the intervals of the pipe groups in the height direction.

4. The invention optimizes the optimal relation of the parameters of the electric heating device through a large amount of experiments and numerical simulation, thereby realizing the optimal heating efficiency.

5. The triangular layout of the multi-electric heating device with the novel structure is designed, the structural parameters of the layout are optimized, and the heating efficiency can be further improved through the layout.

Description of the drawings:

FIG. 1 is a schematic view of a steam (hot water) heating apparatus of the present invention;

FIG. 2 is a schematic view of a heating arrangement of the evaporator and the water heater;

FIG. 3 is a schematic view of a flat tube configuration in a heat utilization apparatus;

FIG. 4 is a schematic view of an evaporator/water heater configuration;

fig. 5 is a top view of the electric heating apparatus of the present invention.

Fig. 6 is a front view of the electric heating apparatus of the present invention.

Fig. 7 is a front view of another embodiment of the electric heating apparatus of the present invention.

Fig. 8 is a schematic diagram of the dimensional structure of the electric heating apparatus of the present invention.

Fig. 9 is a schematic layout of the electric heating apparatus of the present invention in a circular cross-section heater.

FIG. 10 is an example of a Raman spectrum;

FIG. 11 is an example of a Raman spectrum;

FIG. 12 is an example of a Raman spectrum;

FIG. 13 is a thin layer chromatogram observed under an ultraviolet lamp at 254 nm;

FIG. 14 is a thin layer chromatogram viewed under sunlight (left) and under an ultraviolet lamp 365 nm (right).

In the figure: 1. the heat exchanger comprises a tube group, a left tube group 11, a

right tube group

12, 21, a left collecting tube, 22, a right collecting tube, 3, a free end, 4, a free end, 5, a free end, 6, a free end, 7, an arc-shaped tube, 8, a middle evaporation tube, 9, an electric heater, 10 a first tube orifice, 13 a second tube orifice, 14 a left return tube, 15 a right return tube, 16 an evaporator, 17 a heat utilization device, 18 flat tubes, 19 chromatographic plates, 161 a water tank, 20 pipelines, 21 a water heater, 22 pipelines, 23 a first valve, 24 a second valve, 25 an electric heating device, inlet tubes, 26 outlet tubes, 27.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings.

In this document, "/" denotes division and "×", "denotes multiplication, referring to formulas, if not specifically stated.

As shown in fig. 1, a steam heating device comprises an evaporator 16, the evaporator comprises a steam outlet, the steam outlet is connected with one or more heat utilization devices 17 through a pipeline 20, the heat utilization devices 17 exchange heat and then circulate back to the evaporator 16, at least one heat utilization device 17 comprises flat tubes 18, and devices 19 needing to be heated are arranged on the upper portions of the flat tubes 18.

The steam heating device is provided with the steam heating device, and the steam can keep constant temperature under constant pressure, so that the corresponding constant temperature can be kept, and the temperature of the heated part is constant. And the steam can ensure high-temperature heating.

Preferably, the heat utilization device is a thin layer chromatography imaging and raman spectroscopy collector 17, a flat tube 18 is arranged at the lower part of the thin layer chromatography imaging and raman spectroscopy collector 17, and a chromatographic plate 19 is arranged at the upper part of the flat tube.

The phenomena of fake and inferior products and illegal addition of chemical drugs in food, medicine and cosmetic markets in China are frequent, the product quality is unstable, the illegal addition amount and components are disordered, and the health and safety of people are seriously influenced. The further improvement of the analysis and detection technology is one of the main problems which are urgently needed to be solved at present, and the traditional technology is difficult to realize the instant and quick quality evaluation of illegally added chemical drugs, so that the key technology of innovative and quick detection is urgently needed at present. At present, TLC (thin layer chromatography) is a common method for rapid detection, but the detection method needs to keep constant temperature imaging and detection, for example, about 105 ℃, and the prior art generally adopts an infrared heating method, so that the temperature is not well controlled, and resources are wasted and the efficiency is low. According to the invention, the steam heating device is introduced into the thin-layer chromatography imaging and Raman spectrum acquisition instrument for the first time, and the thin-layer chromatography imaging and Raman spectrum acquisition instrument can realize good thin-layer chromatography imaging and Raman spectrum acquisition through constant steam temperature.

Preferably, the upper outer wall surface of the flat tube 18 is provided with a groove 19, and the chromatographic plate is arranged in the groove. Such as shown in fig. 3.

Preferably, the evaporator is an electrically heated evaporator.

Preferably, the steam temperature at the steam outlet is 103-108 ℃.

Preferably, the steam temperature at the steam outlet is 105 degrees celsius.

In the using process, steam is introduced to heat the chromatographic plate, the temperature of the chromatographic plate is kept constant, the residual developing agent is volatilized, thin-layer chromatography imaging can be performed quickly, spectrum collection can be performed through the Raman probe, and the collected spectrum is recorded into a system to be put in storage or inspected quickly.

Preferably, a plurality of heat utilization devices may be provided at the same time, and the heat utilization devices may be configured in parallel. Such as multiple raman spectrometers and thin layer chromatography imaging.

Preferably, the conduit 20 is provided with a second valve 24 for controlling the steam flow into the heat utilization device.

As a modification, the present invention may use hot water for low temperature heating. As shown in fig. 1, a hot water heating device comprises a water heater 21, the water heater comprises a hot water outlet, the hot water outlet is connected with one or more heat utilization devices 17 through a pipeline 22, the heat utilization devices 17 exchange heat and then circulate back to the water heater 21, at least one heat utilization device 17 comprises flat tubes 18, and devices 19 needing to be heated are arranged on the upper portions of the flat tubes 18.

Preferably, the pipe 22 is provided with a first valve 23 for controlling the flow of hot water into the heat utilization device.

According to the invention, hot water heating is arranged, so that low-temperature heating can be realized by hot water, and the temperature and the flow of the hot water can be controlled in the heating process, thereby ensuring the heating quality.

The food, medicine and cosmetic markets in China are counterfeit and inferior, the phenomenon of illegal addition of chemical medicines is frequent, the product quality is unstable, the illegal addition amount and components are disordered, and the health and safety of people are seriously influenced. The further improvement of the analysis and detection technology is one of the main problems which are urgently needed to be solved at present, and the traditional technology is difficult to realize the instant and quick quality evaluation of samples, so that the key technology of innovative and quick detection is urgently needed at present. At present, TLC (thin layer chromatography) is a common method for rapid detection, but the monitoring method rapidly volatilizes residual developing solvent, is beneficial to thin layer chromatography imaging, then sprays glue on a chromatography plate, needs low-temperature heating after glue spraying, volatilizes solvent in the glue, for example, about 35 ℃, and the prior art generally adopts an infrared heating method or hair drying, so that the temperature is difficult to control, and the resource waste and the efficiency are low. The invention introduces the hot water heating device into the thin-layer chromatography imaging and Raman spectrum acquisition instrument for the first time, and realizes quick and effective volatilization by hot water heating.

Preferably, the water heater is an electrically heated water heater.

Preferably, the hot water temperature at the hot water outlet is 30-40 ℃.

Preferably, the hot water outlet has a hot water temperature of 35 degrees celsius.

Preferably, the hot water outlet is provided at an upper portion of a sidewall of the water tank.

In the using process of the invention, hot water is firstly introduced to heat the chromatographic plate, so as to keep and control the volatilization stability of the chromatographic plate glue.

Preferably, a plurality of heat utilization devices may be provided at the same time, and the heat utilization devices may be configured in parallel. For example, a plurality of thin layer chromatography and raman spectrum collectors are provided.

As an improvement, the invention can be simultaneously provided with the combined use of steam heating and hot water heating, and in the using process, the spreading agent and the glue on the thin-layer plate are volatilized by the hot water heating, and then the steam heating is switched to carry out the collection of the Raman spectrum.

As shown in fig. 2, a hot water and steam switching heating device comprises a water heater 21, wherein the water heater comprises a hot water outlet, the hot water outlet is connected with one or more heat utilization devices 17 through a pipeline 22, and the heat utilization devices 17 exchange heat and then circulate back to the water heater 21; the heat recovery device further comprises an evaporator 16, the evaporator comprises a steam outlet, the steam outlet is connected with one or more heat utilization devices 17 through a pipeline 20, and the heat utilization devices 17 are subjected to heat exchange and then circulate back to the evaporator 16. The conduit 22 is provided with a first valve 23 and the conduit 20 is provided with a second valve 24. The steam heating and the hot water heating are switched by opening and closing the first valve and the second valve, thereby switching between the high temperature heating and the low temperature heating.

In operation, low-temperature heating is firstly carried out, the glue is volatilized, then steam heating is switched to carry out Raman spectrum collection.

The remaining undescribed features, such as the water heater, evaporator and heat utilization device, are the same as previously described and are not described.

The evaporator 16/water heater 21 has a similar structure. As shown in fig. 4, the electric heating device comprises a water tank 161 and an electric heating device 25 arranged in the water tank, wherein the electric heating device comprises a middle evaporation tube 8, a left header 21, a right header 22 and a tube group 1, the tube group 1 comprises a left tube group 11 and a right tube group 12, the left tube group 11 is communicated with the left header 21 and the middle evaporation tube 8, the right tube group 12 is communicated with the right header 22 and the middle evaporation tube 8, so that the middle evaporation tube 8, the left header 21, the right header 22 and the tube group 1 form a heating fluid closed cycle, the middle evaporation tube 8 is filled with a phase-change fluid, an electric heater 9 is arranged in the middle evaporation tube 8, each tube group 1 comprises a plurality of arc-shaped tubes 7 in an arc shape, the ends of the adjacent arc-shaped tubes 7 are communicated, so that the plurality of arc-shaped tubes 7 form a series structure, and the end parts of the arc-shaped tubes 7 form arc-free ends 3-6; the middle evaporation tube comprises a first tube orifice 10 and a second tube orifice 13, the first tube orifice 10 is connected with the inlet of the left tube group 11, the second tube orifice 13 is connected with the inlet of the right tube group 12, the outlet of the left tube group 11 is connected with the left header 21, and the outlet of the right tube group 12 is connected with the right header 22; the first and second nozzles 10 and 13 are arranged on opposite sides of the central evaporator tube 8.

Preferably, a left return pipe 14 is provided between the left header 21 and the middle evaporation pipe 8, and a right return pipe 14 is provided between the right header 22 and the middle evaporation pipe 8. Preferably, the return pipe is arranged at the bottom.

The fluid heats and evaporates in the middle evaporation tube 8, flows to the left and

right headers

21 and 22 along the arc tube bundle, and the fluid can expand in volume after being heated, so that steam is formed, the volume of the steam is far larger than that of water, and the formed steam can flow in the coil in a quick impact manner. Because volume expansion and steam flow can induce the arc tube free end to vibrate, the vibration is transferred to the surrounding heat exchange fluid at the free end of the heat exchange tube in the vibrating process, and the fluid can also generate disturbance each other, so that the surrounding heat exchange fluid forms disturbance flow, a boundary layer is damaged, and the purpose of enhancing heat transfer is realized. The fluid is condensed and released heat in the left and right collecting pipes and then flows back to the middle evaporation pipe through the return pipe.

According to the invention, the prior art is improved, and the condensation collecting pipe and the pipe groups are respectively arranged into two pipes which are distributed on the left side and the right side, so that the pipe groups distributed on the left side and the right side can perform vibration heat exchange descaling, the heat exchange vibration area is enlarged, the vibration can be more uniform, the heat exchange effect is more uniform, the heat exchange area is increased, and the heat exchange and descaling effects are enhanced.

Preferably, the arc pipes of the left pipe group are distributed by taking the axis of the left collecting pipe as the center of a circle, and the arc pipes of the right pipe group are distributed by taking the axis of the right collecting pipe as the center of a circle. The left collecting pipe and the right collecting pipe are arranged as circle centers, so that the distribution of the arc-shaped pipes can be better ensured, and the vibration and the heating are uniform.

Preferably, the tube group is plural.

Preferably, the position of the right tube group (including the right header) is a position of the left tube group (including the left header) rotated by 180 degrees (angle) along the axis of the middle evaporation tube. Through such setting, can make the arc pipe distribution of heat transfer reasonable more even, improve the heat transfer effect.

Preferably, the

headers

8, 21, 22 are provided along the height direction.

Preferably, the left tube group 21 and the right tube group 22 are staggered in the height direction, as shown in fig. 2. Through the staggered distribution, can make to vibrate heat transfer and scale removal on the not co-altitude for the vibration is more even, strengthens heat transfer and scale removal effect.

Preferably, the tube group 2 (e.g., the same side (left side or right side)) is provided in plural along the height direction of the middle evaporation tube 8, and the tube diameter of the tube group 2 (e.g., the same side (left side or right side)) becomes smaller from the top to the bottom.

Preferably, the tube diameters of the arc-shaped tubes of the tube group (for example, the same side (left side or right side)) are gradually decreased and increased along the top-down direction of the middle evaporation tube 8.

The pipe diameter range through the nest of tubes increases, can guarantee that more steam gets into through upper portion and control the box, guarantees that the distribution of all nest of tubes interior steam is even, further reinforces the heat transfer effect for whole vibration effect is even, and the heat transfer effect increases, further improves heat transfer effect and scale removal effect. Experiments show that better heat exchange effect and descaling effect can be achieved by adopting the structural design.

Preferably, the tube groups on the same side (left side or right side) are provided in plurality along the height direction of the middle evaporation tube 8, and the distance between the adjacent tube groups on the same side (left side or right side) becomes larger from the top to the bottom.

Preferably, the spacing between the tube groups on the same side (left side or right side) in the height direction of the first header is increased to a larger extent.

The interval amplitude through the nest of tubes increases, can guarantee that more steam passes through upper portion and gets into about the collector, guarantees that the distribution of all nest of tubes steam is even, further reinforces the heat transfer effect for whole vibration effect is even, and the heat transfer effect increases, further improves heat transfer effect and scale removal effect. Experiments show that better heat exchange effect and descaling effect can be achieved by adopting the structural design.

In tests, it was found that the tube diameters, distances and tube diameters of the left header 21, the right header 22, the middle evaporation tube 8 can have an influence on the heat exchange efficiency and uniformity. If the distance between the collector is too big, then heat exchange efficiency is too poor, and the distance between the arc pipe is too little, then the arc pipe distributes too closely, also can influence heat exchange efficiency, and the pipe diameter size of collector and heat exchange tube influences the volume of the liquid or the steam that hold, then can exert an influence to the vibration of free end to influence the heat transfer. Therefore, the pipe diameters and distances of the left header 21, the right header 22, the middle evaporation pipe 8 and the pipe diameters of the arc pipes have a certain relationship.

The invention provides an optimal size relation summarized by numerical simulation and test data of a plurality of heat pipes with different sizes. Starting from the maximum heat exchange amount in the heat exchange effect, nearly 200 forms are calculated. The dimensional relationship is as follows:

the distance between the center of the middle evaporation tube 8 and the center of the left header 21 is equal to the distance between the center of the middle evaporation tube 8 and the center of the right header 21, L, the tube diameter of the left header 21, the tube diameter of the middle evaporation tube 8, and the radius of the right header 22 are R, the radius of the axis of the innermost arc tube in the arc tubes is R1, and the radius of the axis of the outermost arc tube is R2, so that the following requirements are met:

R1/R2=a*(R/L)²-b (R/L) + c; wherein a, b, c are parameters, wherein 4.834<a<4.835，1.390<b<1.391，0.5585<c<0.5590, respectively; preferably, a is 4.8344, b is 1.3906, and c is 0.5587.

Preferably, 34< R <61 mm; 114< L <191 mm; 69< R1<121mm, 119< R2<201 mm.

Preferably, the number of curved tubes of the tube set is 3-5, preferably 3 or 4.

Preferably, 0.57< R1/R2< 0.61; 0.3< R/L < 0.32.

Preferably, 0.583< R1/R2< 0.60; 0.304< R/L < 0.316.

Preferably, the radius of the arc tube is preferably 10-40 mm; preferably 15 to 35mm, more preferably 20 to 30 mm.

Preferably, the centers of the left header 21, the right header 22 and the middle evaporation tube 8 are on a straight line.

Preferably, the arc between the ends of the free ends 3, 4, centered on the central axis of the left header, is 95-130 degrees, preferably 120 degrees. The same applies to the curvature of the free ends 5, 6 and the free ends 3, 4. Through the design of the preferable included angle, the vibration of the free end is optimal, and therefore the heating efficiency is optimal.

The heating power of the electric heater as the evaporator is preferably 1800-2000W, more preferably 1900W. The water heater is 1000-1200W, preferably 1100W.

Preferably, the box body has a circular cross section, and is provided with a plurality of electric heating devices, wherein one electric heating device is arranged at the center of the circular cross section and the other electric heating devices are distributed around the center of the circular cross section.

Preferably, the tube bundle of the tube bank 1 is an elastic tube bundle.

The heat exchange coefficient can be further improved by arranging the tube bundle of the tube group 1 with an elastic tube bundle.

Further preferably, the electric heater is an electric heating rod.

The number of the pipe groups 1 is multiple, and the plurality of pipe groups 1 are in a parallel structure.

The water heater/evaporator shown in fig. 10 has a circular cross-sectional housing with the plurality of electric heating means disposed within the circular housing. Preferably, three electric heating devices are arranged in the shell, and extension lines of central connecting lines of the left collecting box, the right collecting box and the middle evaporation tube of the electric heating devices form an inscribed regular triangle with a circular cross section. Through such setting, can make and to fully reach vibrations and heat transfer purpose in can making the heater, improve the heat transfer effect.

Learn through numerical simulation and experiment, electric heater unit's size and circular cross section's diameter have very big influence to the heat transfer effect, electric heater unit is oversize can lead to adjacent interval too little, the space that middle formation is too big, middle heating effect is not good, the heating is inhomogeneous, on the same way, electric heater unit size undersize can lead to adjacent interval too big, leads to whole heating effect not good. Therefore, the invention obtains the optimal size relation through a large amount of numerical simulation and experimental research.

The distance between the centers of the left collecting box and the right collecting box is L1, the side length of the inscribed regular triangle is L2, the radius of the axis of the innermost arc pipe in the arc pipes is R1, and the radius of the axis of the outermost arc pipe is R2, so that the following requirements are met:

10*(L1/L2)=d*(10*R1/R2)-e*(10*R1/R2)²-f; wherein d, e, f are parameters,

42.69<d<42.71,3.63<e<3.64,119.9<f<120.1；

further preferably, d =42.702, e =3.634, f = 122.01;

with 720< L2<1130mm preferred. Preferably 0.3< L1/L2< 0.6.

Further preferably 0.32< L1/L2< 0.4.

Through the layout of the three electric heating devices with optimized structure, the whole heat exchange effect can reach the best heat exchange effect.

Although the present invention has been described with reference to the preferred embodiments, it is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A device for heating a chromatographic plate by low-temperature hot water comprises a water heater, wherein the water heater comprises a hot water outlet, the hot water outlet is connected with one or more heat utilization devices through a pipeline, hot water circulates back to the water heater after being subjected to heat exchange by the heat utilization devices, at least one heat utilization device comprises a flat tube, a device to be heated is arranged on the upper portion of the flat tube, and the temperature of the hot water at the hot water outlet is 30-40 ℃; the evaporator comprises a water tank and an electric heating device arranged in the water tank, wherein the electric heating device comprises a middle evaporation tube, a left collecting tube, a right collecting tube and tube groups, each tube group comprises a left tube group and a right tube group, the left tube group is communicated with the left collecting tube and the middle evaporation tube, the right tube group is communicated with the right collecting tube and the middle evaporation tube, so that the middle evaporation tube, the left collecting tube, the right collecting tube and the tube groups form heating fluid closed circulation, the electric heaters are arranged in the middle evaporation tube, the tube groups are multiple, each tube group comprises a plurality of arc-shaped tubes, the end parts of the adjacent arc-shaped tubes are communicated, the arc-shaped tubes form a series structure, and the end parts of the arc-shaped tubes form free ends of the arc-shaped tubes; the middle evaporation tube comprises a first tube orifice and a second tube orifice, the first tube orifice is connected with the inlet of the left tube group, the second tube orifice is connected with the inlet of the right tube group, the outlet of the left tube group is connected with the left collecting tube, and the outlet of the right tube group is connected with the right collecting tube; the first pipe orifice and the second pipe orifice are arranged on two opposite sides of the middle evaporation pipe; a left return pipe is arranged between the left collecting pipe and the middle evaporation pipe, and a right return pipe is arranged between the right collecting pipe and the middle evaporation pipe; the heat utilization device is a thin-layer chromatography imaging and Raman spectrum acquisition instrument, the lower portion of the acquisition instrument is provided with a flat tube, the flat tube is connected with a hot water outlet, the upper portion of the flat tube is provided with a thin-layer chromatography plate placing table, and the device to be heated is a chromatography plate.

2. The apparatus of claim 1, wherein the conduit is provided with a first valve for controlling the flow of hot water into the heat utilization device.

3. The apparatus of claim 1, wherein the upper exterior wall of the flattened tube is provided with a recess, and the TLC plate is disposed within the recess.

4. The apparatus of claim 1, the hot water outlet hot water temperature being 35 degrees celsius.

5. The apparatus of claim 1, wherein the hot water outlet is provided at an upper portion of a sidewall of the water tank.