Chromatographic detection system

Abstract

The utility model discloses a chromatographic detection system, which comprises a heating device, the heating device is used for heating gas and then conveying the gas into the high-temperature valve box; the output end of the high-temperature valve box conveys gas into a gas chromatograph through a heating pipe to detect the high-temperature gas; the temperature is raised to 300 DEG C through a designed heating device, a designed high-temperature valve box and a designed heating pipe, nitrogen and organic gas are sequentially introduced, the organic gas is introduced into a gas chromatograph, the introduced nitrogen is replaced, a quantitative ring in a gas chromatography valve box is filled, the organic gas in the quantitative ring is controlled for detection, the detection effect can be evaluated in real time, subsequent sampling is avoided, and the detection efficiency is improved. And a sample preparation process saves a lot of time. Meanwhile, parameters of the introduced organic gas are adjusted in time according to a detection result.

Description

TECHNICAL FIELD

[0001] The utility model relates to organic matter detection field especially, and it relates to a chromatographic detection system. BACKGROUND

[0002] The experiment of involving ammonia oxidation in the laboratory at present often uses small fluidized bed or fixed bed, reaction temperature is generally above 300 DEG C, and the high boiling point organic matter contained in the product is usually cooled first, then dissolved with organic solvent, phase separation, and then detected by the way of re-quantification, which is time-consuming and has hysteresis. UTILITARY MODEL

[0003] The utility model discloses a chromatographic detection system which solves the problems in the prior art.

[0004] In order to achieve the above object, the utility model adopts the following technical scheme: a chromatographic detection system, comprising:

[0005] Heating device;

[0006] The heating device heats the gas and then delivers it to the high-temperature valve box;

[0007] The output end of the high-temperature valve box delivers the gas to the gas chromatograph through the heating pipe to detect the high-temperature gas.

[0008] Further description of the above technical scheme: the heating device includes an insulation jacket, and the input end of the insulation jacket is connected with a flowmeter.

[0009] Further description of the above technical scheme: the inner side of the insulation jacket is provided with a first electric heater to heat the cavity on the inner side of the insulation jacket.

[0010] Further description of the above technical scheme: a first temperature measuring thermocouple is arranged on the end face near the input end of the insulation jacket, and a first temperature control thermocouple is arranged on the pipeline connected with the output end of the insulation jacket.

[0011] Further description of the above technical scheme: the high-temperature valve box includes a box body, the box body is provided with two input ends and one output end, and is connected through a three-way valve, any input end is connected with the output end of the heating device through a pipeline, and the other input end is connected with an organic gas.

[0012] Further description of the above technical scheme: at least one second temperature measuring thermocouple and a second temperature control thermocouple are arranged on the box body, and a second electric heater is arranged on the bottom of the box body.

[0013] As a further description of the above technical solution: the filter is arranged on the side close to the output end of the three-way valve, and the speed-regulating fan is arranged on the inner wall of the box.

[0014] As a further description of the above technical solution: the heating pipe comprises an outer pipe and an inner pipe, and the third temperature measuring thermocouple and the third temperature control thermocouple are arranged on the inner pipe.

[0015] As a further description of the above technical solution: at least one third electric heater is arranged in the inner pipe.

[0016] As a further description of the above technical solution: the heating device, the high-temperature valve box and the heating pipe are connected with the temperature control electric cabinet.

[0017] The above technical solution has the following advantages or beneficial effects:

[0018] 1. The heating device, the high-temperature valve box and the heating pipe are connected with the temperature control electric cabinet. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 A structure diagram of the chromatographic detection system is provided in the utility model.

[0020] Figure 2 A structure diagram of the heating device in the utility model is provided.

[0021] Figure 3 A structure diagram of the high-temperature valve box in the utility model is provided.

[0022] Figure 4 A structure diagram of the heating pipe in the utility model is provided.

[0023] LEGEND:

[0024] 1. heating device; 11. heat preservation jacket; 12. flow meter; 13. first electric heater; 14. first temperature measuring thermocouple; 15. first temperature control thermocouple; 2. high-temperature valve box; 21. box; 22. three-way valve; 23. second temperature measuring thermocouple; 24. second temperature control thermocouple; 25. second electric heater; 26. filter; 27. speed-regulating fan; 3. heating pipe; 31. outer pipe; 32. inner pipe; 33. third temperature measuring thermocouple; 34. third temperature control thermocouple; 35. third electric heater; 4. gas chromatograph. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the utility model.

[0026] With reference to Figures 1-4 The utility model provides an embodiment: a chromatographic detection system, include: heating device 1, heating device 1 is transported to high temperature valve box 2 after heating gas, the output of high temperature valve box 2 is transported to gas chromatograph 4 through heating tube 3, and high temperature gas is detected.

[0027] In the embodiment, heating device 1, high temperature valve box 2 and heating tube 3 are controlled to be heated to 300 DEG C through the temperature control electric cabinet connected, nitrogen is input from heating device 1, nitrogen fills the inside, air is discharged, organic gas is input, is transported to gas chromatograph and is detected, is heated to 300 DEG C through the heating device and high temperature valve box and heating tube, nitrogen and organic gas are input in turn, organic gas is input into gas chromatograph, replaces the nitrogen input and fills the quantitative ring in gas chromatograph valve box, controls the organic gas in quantitative ring and detects, can real-time evaluation detection effect, avoids subsequent sampling, and saves a lot of time. At the same time, the organic gas parameter input is adjusted in time according to the detection result.

[0028] The temperature control electric cabinet has at least three temperature measurement and control circuits, each temperature control circuit is independent and does not affect each other, each temperature control circuit is provided with a relay, a fuse and a temperature control instrument, and is adjusted by PID to ensure that each temperature control is stable and has small fluctuation. The device is prior art and will not be described in detail.

[0029] Heating device 1 includes a heat preservation jacket 11, the input end of the heat preservation jacket 11 is connected with a flowmeter 12, the inside of the heat preservation jacket 11 is provided with a first electric heater 13, the cavity on the inside of the heat preservation jacket 11 is heated, a first temperature measuring thermocouple 14 is arranged on the end face of the side close to the input end of the heat preservation jacket 11, and a first temperature control thermocouple 15 is arranged at the pipeline connected with the output end of the heat preservation jacket 11.

[0030] In the embodiment, nitrogen used for purging is input into heating device 1, the nitrogen flow is adjusted by the flowmeter 12, the nitrogen input into the input end is heated by the first electric heater 13, the temperature of the nitrogen at the input end is measured by the first temperature control thermocouple 15, and the nitrogen at the output end is measured by the first temperature measuring thermocouple 14, so that the heating device 1 can heat the purging nitrogen to a specified temperature.

[0031] The high-temperature valve box 2 comprises a box body 21 provided with two input ends and one output end connected through a three-way valve 22, any one of the input ends is connected with the output end of the heating device 1 through a pipeline, and the other input end is connected with an organic gas; at least one second temperature measuring thermocouple 23 and a second temperature control thermocouple 24 are arranged on the box body 21, and a second electric heater 25 is arranged at the bottom of the box body 21; a filter 26 is arranged on the side close to the output end of the three-way valve 22, and a speed-regulating fan 27 is arranged at the inner wall of the box body 21.

[0032] In the embodiment, one input end of the box body 21 is connected with the output end of the heating device 1, and heated nitrogen is introduced; the other input end is connected with an organic high-boiling gas for subsequent detection; the output end is connected with the heating pipe 3; the three-gas pipelines are connected through a high-temperature t-shaped three-way pipe; a high-temperature needle valve is arranged at the connection of the three-way valve 22, and the high-temperature needle valve is provided with an extended valve rod extending out of the valve box, so as to facilitate operation. The filter 26 is installed on the side close to the output end, and is connected in a high-temperature stainless steel double sleeve connection mode, so as to facilitate connection and disassembly. The filter 26 is installed to filter the gas entering the gas chromatograph 4, so as to protect the gas chromatograph.

[0033] The second temperature measuring thermocouple 23 is provided with two second temperature measuring thermocouples 23 arranged on the upper and lower sides of the box body 21 respectively to detect the temperature, so as to ensure that the temperature in the box body 21 reaches the set temperature and the temperature in the box body 21 is balanced. The speed-regulating fan 27 is arranged at the inner wall of the box body 21, so that the gas in the box body 21 keeps flowing, the temperature in the box body 21 keeps stable and balanced, and a heat preservation layer can be arranged on the outer side of the box body 21.

[0034] The heating pipe 3 comprises an outer pipe 31 and an inner pipe 32, and the inner pipe 32 is provided with a third temperature measuring thermocouple 33 and a third temperature control thermocouple 34.

[0035] In the embodiment, the use of the heating pipe 3 can keep the pipeline temperature uniform, prevent the high-boiling organic gas from being cooled, and affect the detection result. The outer pipe 31 is an aluminum casting pipe, and a stainless steel inner pipe 32 with a diameter of 3-6 mm is embedded in the inner pipe 32. The inner pipe 32 is heated or heat-preserved through the third electric heater 35.

[0036] The third electric heater 35 is provided with two electric heating wires, one of which is used normally and the other of which is used as a backup. The heating pipe 3 and the electric heating wires are integrally poured with aluminum water, so that the whole pipe is uniformly heated. The heating pipe 3 is provided with the third temperature measuring thermocouple 33 and the third temperature control thermocouple 34. If the length of the heating pipe exceeds 1 m, the temperature measuring loop needs to be increased.

[0037] Further, a heat preservation sleeve can be added outside the outer tube 31 to keep warm, and prevent scalding, and the third temperature measuring thermocouple 33 and the third temperature control thermocouple 34 pass through the heat preservation sleeve, the outer tube 31 and the inner tube 32 to detect and control the temperature in the tube.

[0038] The gas chromatograph 4 is provided with a valve box, a six-way valve, a gas quantification ring, a split / splitless injection port, a capillary column and a hydrogen flame detector (which are prior art and will not be described in detail), and is used to detect the organic gas input. The output end of the heating tube 3 is connected to the gas chromatograph through a reducing two-way valve, the valve box temperature of the gas chromatograph is consistent with the system temperature, and the gas quantification ring is inertized to prevent memory effect.

[0039] In a specific embodiment, the reaction gas of m-xylene ammoxidation is detected in real time. The reaction temperature of m-xylene ammoxidation is usually 380-450 DEG C, the main product of ammonia oxidation is m-phthalonitrile with a boiling point of 270 DEG C, the temperature control electric cabinet controls the heating device 1, the high-temperature valve box 2 and the heating tube 3 to be heated to 300 DEG C (higher than the boiling point of the high-boiling organic gas, to prevent high-boiling organic matter from condensing), after heating, nitrogen is input to purge the whole system, when starting detection, the high-temperature needle valve of the high-temperature valve box 2 for inputting nitrogen is closed, the needle valves of the organic gas input end and the output end are opened, the high-temperature organic gas containing m-phthalonitrile passes through the high-temperature valve box 2 and the heating tube 3 in sequence, and enters the gas chromatograph to fill and replace the gas quantification ring. After 3-5 min, the gas replacement is completed, the six-way valve of the gas chromatograph is switched, the organic gas enters the gas chromatograph for detection. The needle valve of the organic gas input end is closed, the needle valve of the nitrogen input end is opened, and the whole system is purged, and one organic gas sampling and detection operation is completed.

[0040] Through the detection data of the gas chromatograph, the whole system can detect the ammonia oxidation reaction in real time, and the complicated material collection, phase separation and quantitative operation are avoided, and the labor and a large amount of time are saved. Through the system, the reaction parameters such as reaction temperature and feed ratio can be conveniently adjusted according to the detection results, and the whole reaction system is efficient and simple.

[0041] Finally, it should be noted that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or make equivalent replacements to some technical features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A chromatographic detection system characterized by, Include: Heating device (1); The heating device (1) heats the gas and delivers it to the high-temperature valve box (2); The output end of the high-temperature valve box (2) delivers the gas to the gas chromatograph (4) through the heating pipe (3) to detect the high-temperature gas; The heating device (1) comprises a heat preservation jacket (11), and the input end of the heat preservation jacket (11) is connected with a flowmeter (12); The inner side of the heat preservation jacket (11) is provided with a first electric heater (13) for heating the cavity on the inner side of the heat preservation jacket (11); The end face near the input end side of the heat preservation jacket (11) is provided with a first temperature measuring thermocouple (14), and the pipeline connected with the output end of the heat preservation jacket (11) is provided with a first temperature control thermocouple (15); The high-temperature valve box (2) comprises a box body (21), the box body (21) is provided with two input ends and an output end, and is connected through a three-way valve (22), any input end is connected with the output end of the heating device (1) through a pipeline, and the other input end is connected with an organic gas; The box body (21) is provided with at least one second temperature measuring thermocouple (23) and a second temperature control thermocouple (24), and the bottom of the box body (21) is provided with a second electric heater (25); The three-way valve (22) is provided with a filter (26) near the output end, and the inner wall of the box body (21) is provided with a speed regulating fan (27).

2. The chromatographic detection system of claim 1, wherein: The heating pipe (3) comprises an outer pipe (31) and an inner pipe (32), and the inner pipe (32) is provided with a third temperature measuring thermocouple (33) and a third temperature control thermocouple (34).

3. The chromatographic detection system of claim 2, wherein: The inner pipe (32) is provided with at least one third electric heater (35).

4. The chromatographic detection system of claim 1, wherein: The heating device (1), the high-temperature valve box (2) and the heating pipe (3) are connected with a temperature control electric cabinet.

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