阅读说明：本技术 一种气相色谱仪分流进样系统及其工作方法 (Gas chromatograph flow-dividing and sample-feeding system and working method thereof ) 是由 蒋立军 刘锦辉 袁敏 曾艳芬 李传兵 黄国君 黄永春 吴为龙 于 2020-12-09 设计创作，主要内容包括：本发明涉及一种气相色谱仪分流进样系统及其工作方法,该系统包括进样器以及控制组件,进样器包括从外至内依序设置的进样外壳、支撑架、卡箍、温度传感器、发热管、衬管以及样品填充管,支撑架与进样外壳内设有保温隔离结构,温度传感器以及发热管分别与控制组件连接,衬管内设有第一通槽。本发明通过设置进样器和控制组件,进样器包括从外至内依序设置的进样外壳、支撑架、卡箍、温度传感器、发热管、衬管以及样品填充管,且在支撑架与进样外壳内设有保温隔离结构,衬管全密封,组分不会污染发热管,实现可全自动控制温度,设置保温隔热结构,降低温度衰减程度。(The invention relates to a gas chromatograph shunt sampling system and a working method thereof, the system comprises a sample injector and a control assembly, the sample injector comprises a sampling shell, a support frame, a hoop, a temperature sensor, a heating tube, a liner tube and a sample filling tube which are sequentially arranged from outside to inside, a heat insulation isolation structure is arranged in the support frame and the sampling shell, the temperature sensor and the heating tube are respectively connected with the control assembly, and a first through groove is arranged in the liner tube. According to the invention, the sample injector and the control assembly are arranged, the sample injector comprises a sample injection shell, a support frame, a hoop, a temperature sensor, a heating tube, a liner tube and a sample filling tube which are sequentially arranged from outside to inside, and a heat insulation isolation structure is arranged in the support frame and the sample injection shell, the liner tube is fully sealed, the components can not pollute the heating tube, the full-automatic temperature control can be realized, the heat insulation structure is arranged, and the temperature attenuation degree is reduced.)

1. The utility model provides a gas chromatograph reposition of redundant personnel sampling system, its characterized in that, includes injector and control assembly, the injector includes from outer to interior appearance shell, support frame, clamp, temperature sensor, heating tube, bushing pipe and the sample filling tube that sets gradually, the support frame with be equipped with heat preservation isolation structure in the appearance shell of advancing, temperature sensor and the heating tube respectively with control assembly connects, be equipped with first logical groove in the bushing pipe.

2. The split-flow sample injection system of a gas chromatograph of claim 1, wherein the thermal insulation structure comprises asbestos.

3. The split-flow sample injection system of a gas chromatograph according to claim 1, wherein an upper sample injection assembly is further connected to the sample injection housing, the upper sample injection assembly includes a carrier gas pipe, a carrier gas valve, and a carrier gas screw, a carrier gas through groove is provided in the carrier gas screw, a second through groove is provided in the carrier gas pipe, the second through groove is communicated with the carrier gas through groove, the carrier gas valve is connected to the carrier gas pipe, the carrier gas valve is connected to the control assembly, the carrier gas pipe is connected to the sample injection housing, and the first through groove is communicated with the second through groove.

4. The split-flow sample injection system of a gas chromatograph according to claim 3, wherein an injection piece is further connected to an upper end of the carrier gas screw, a sample injection port is provided in the injection piece, and a sample injection isolation pad is provided between the injection piece and the carrier gas screw.

5. The split-flow sample injection system of a gas chromatograph according to claim 4, wherein a sample injection sealing top cover is connected to an outer end of the sample injection member, a snap spring is disposed at an upper end of the sample injection sealing top cover, the upper end of the sample injection member extends upward to a position above the sample injection sealing top cover, and the snap spring is connected to the upper end of the sample injection member.

6. The split-flow sample injection system of a gas chromatograph according to any of claims 1 to 5, wherein a tapered through groove is further disposed in the liner, the tapered through groove is located below the first through groove, and the first through groove is communicated with the tapered through groove, a lower sample injection assembly is connected to a lower end of the sample injection shell, the lower sample injection assembly comprises a sample injection pipe, a split flow pipe and a split flow valve, a lower sample injection through groove is disposed in the sample injection pipe, a third through groove is disposed in the split flow pipe, the lower sample injection through groove is respectively communicated with the tapered through groove and the third through groove, and the split flow valve is connected to the split flow pipe.

7. The split sample introduction system of a gas chromatograph according to claim 6, wherein a sample introduction needle is further connected below the lower sample introduction tube, a fourth through groove is formed in the sample introduction needle, and the fourth through groove is communicated with the lower sample introduction through groove.

8. The split sample injection system of a gas chromatograph according to claim 7, wherein a sealing lower cover is connected to an outer side of the lower sample injection tube, the sealing lower cover is connected to a lower end of the sample injection housing, a sample injection needle sealing cover is connected to an outer side of the sample injection needle, and a sample injection needle supporting column is connected to an outer side of the sample injection needle sealing cover.

9. The split-flow sample injection system of a gas chromatograph according to claim 8, the control component comprises a control box, a temperature controller, a circuit board, a power supply, a first electromagnetic valve switch and a second electromagnetic valve switch, the first electromagnetic valve switch is connected with the carrier gas valve, the second electromagnetic valve switch is connected with the flow dividing valve, the first electromagnetic valve switch, the second electromagnetic valve switch and the temperature controller are respectively connected with the circuit board, the power supply is connected with the circuit board, the first electromagnetic valve switch, the second electromagnetic valve switch, the temperature controller, the circuit board and the power supply are respectively arranged in the control box, the circuit board comprises an MCU and a power heating drive circuit, and the temperature sensor, the power heating drive circuit, the heating tube and the temperature controller are respectively connected with the MCU.

10. A working method of a gas chromatograph split-flow sample injection system is characterized by comprising the following steps:

the control assembly controls the heating time and temperature of the heating tube according to a preset temperature control curve PID parameter, the temperature detected by the temperature sensor is transmitted to the control assembly in real time, the heating time and temperature of the heating tube are adjusted by the control assembly, and the control assembly sets a shunting proportion or does not shunt and realizes shunting sample introduction control with the opening and closing time of the first electromagnetic valve switch and the second electromagnetic valve switch through a program.

Technical Field

The invention relates to a gas chromatograph, in particular to a gas chromatograph flow-dividing and sample-feeding system and a working method thereof.

Background

In the analysis of the gas chromatograph, the sample performance, the sample content, the sample components, the sample state, the analysis purpose, the analysis requirement and the like have different requirements on a sample introduction system. Common sampling systems include a shunt sampling system, a non-shunt sampling system, a temperature programmed gasification sampling system and the like, which greatly improve the quantitative accuracy of different sample analyses. The split-flow sample injection is that a sample with larger volume is injected into a gasification chamber of a gas capillary column chromatograph, the sample is uniformly mixed with carrier gas after being gasified by temperature programming, the sample is split into two parts with greatly different flow rates by a splitter according to a proportion, wherein the part with smaller flow rate enters a capillary column, and the part with larger flow rate is discharged.

However, the heating shunt part of the current sampling system is separated and exposed, has no temperature sensor, belongs to semi-automatic or open-loop temperature control, and cannot realize full-automatic temperature control; in addition, the sampling system is not provided with a heat preservation and insulation device, and the liner tube is inconvenient to clean, the sample injector is far away from the GC chromatograph, and the temperature attenuation is quick.

Therefore, it is necessary to design a new system to realize full-automatic temperature control, and to provide a thermal insulation structure to reduce the temperature attenuation.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a gas chromatograph flow-dividing and sample-feeding system and a working method thereof.

In order to achieve the purpose, the invention adopts the following technical scheme: the utility model provides a gas chromatograph reposition of redundant personnel sampling system, includes injector and control assembly, the injector includes from outer to interior appearance shell, support frame, clamp, temperature sensor, heating tube, bushing pipe and the sample filling tube that sets gradually, the support frame with be equipped with heat preservation isolation structure in the appearance shell of advancing, temperature sensor and the heating tube respectively with control assembly connects, be equipped with first logical groove in the bushing pipe.

The further technical scheme is as follows: the heat-insulating isolation structure comprises asbestos.

The further technical scheme is as follows: the last appearance subassembly of advancing of still being connected with of appearance shell, it includes carrier gas pipe, carrier gas valve and carrier gas screw rod to go up the appearance subassembly, it leads to the groove to be equipped with the carrier gas in the carrier gas screw rod, the carrier gas intraductal second that is equipped with leads to the groove, the second lead to the groove with the carrier gas leads to the groove intercommunication, the carrier gas valve connect in on the carrier gas pipe, just the carrier gas valve with control assembly connects, the carrier gas pipe with advance the appearance shell and connect, first lead to the groove with the second leads to the groove intercommunication.

The further technical scheme is as follows: the upper end of the carrier gas screw rod is also connected with a sample inlet, a sample inlet is arranged in the sample inlet, and a sample inlet isolation pad is arranged between the sample inlet and the carrier gas screw rod.

The further technical scheme is as follows: the outer end of the sample inlet piece is connected with a sample inlet sealing top cover, the upper end of the sample inlet sealing top cover is provided with a clamp spring, the upper end of the sample inlet piece extends upwards to the upper portion of the sample inlet sealing top cover, and the clamp spring is connected with the upper end of the sample inlet piece.

The further technical scheme is as follows: still be equipped with the toper in the bushing and lead to the groove, the toper leads to the groove and is located the first below that leads to the groove, just first lead to the groove with the groove intercommunication is led to the toper, and the lower extreme of advancing the appearance shell is connected with down advances kind of subassembly, advance kind of subassembly down including advancing kind pipe, shunt tubes and flow divider, advance kind intraductal and advance kind of groove down, be equipped with the third in the shunt tubes and lead to the groove, advance kind down lead to the groove respectively with the toper lead to the groove and third through groove intercommunication, be connected with on the shunt tubes the flow divider.

The further technical scheme is as follows: the lower part of the lower sample inlet pipe is also connected with a sample inlet needle, a fourth through groove is arranged in the sample inlet needle, and the fourth through groove is communicated with the lower sample inlet through groove.

The further technical scheme is as follows: the outside of advancing the appearance pipe down is connected with sealed lower cover, sealed lower cover with the lower extreme of advancing the appearance shell is connected, the outside of advancing the appearance needle is connected with advances the sealed lid of appearance needle, the outside of advancing the sealed lid of appearance needle is connected with advances the appearance needle support column.

The further technical scheme is as follows: control assembly includes control box, temperature controller, circuit board, power and first solenoid valve switch and second solenoid valve switch, first solenoid valve switch with the carrier gas valve is connected, second solenoid valve switch with the flow divider is connected, first solenoid valve switch, second solenoid valve switch and the temperature controller respectively with the circuit board is connected, the power with the circuit board is connected, first solenoid valve switch, second solenoid valve switch the temperature controller the circuit board and the power is arranged in respectively in the control box, the circuit board includes MCU and the power drive circuit that generates heat, temperature sensor power drive circuit that generates heat the heating tube and the temperature controller respectively with MCU connects.

The invention also provides a working method of the gas chromatograph split sampling system, which comprises the following steps:

the control assembly controls the heating time and temperature of the heating tube according to a preset temperature control curve PID parameter, the temperature detected by the temperature sensor is transmitted to the control assembly in real time, the heating time and temperature of the heating tube are adjusted by the control assembly, and the control assembly sets a shunting proportion or does not shunt and realizes shunting sample introduction control with the opening and closing time of the first electromagnetic valve switch and the second electromagnetic valve switch through a program.

Compared with the prior art, the invention has the beneficial effects that: according to the invention, the sample injector and the control assembly are arranged, the sample injector comprises a sample injection shell, a support frame, a temperature sensor, a heating tube and a liner tube which are sequentially arranged from outside to inside, and a heat insulation isolation structure is arranged in the support frame and the sample injection shell, the liner tube is fully sealed, so that the heating tube is not polluted by components, the temperature can be fully automatically controlled, the heat insulation structure is arranged, and the temperature attenuation degree is reduced.

The invention is further described below with reference to the accompanying drawings and specific embodiments.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic perspective view of a sample injector according to an embodiment of the present invention;

FIG. 2 is a schematic perspective view of a sample injector according to an embodiment of the present invention (with the support removed);

FIG. 3 is a schematic diagram of an exploded structure of a sample injector according to an embodiment of the present invention;

FIG. 4 is a schematic sectional view of a sample injector according to an embodiment of the present invention;

fig. 5 is a schematic perspective view of a control assembly according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in detail with reference to the accompanying drawings and the detailed description.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be connected or detachably connected or integrated; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above should not be understood to necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples described in this specification can be combined and combined by one skilled in the art.

As shown in fig. 1 to 5, the present embodiment provides a split-flow sample injection system for a gas chromatograph, which can be applied to an analysis process of the gas chromatograph, and is suitable for an automatic temperature-programmed gasification at the front end of the gas chromatograph, i.e., a capillary chromatographic column, and a thermal cracking desorption and split-flow sample injection device can realize a controllable split-flow/non-split-flow process. The system meets the detection requirement of RoHS2.0 detection standard o-benzene, and a gas chromatograph flow-dividing and sample-injecting system can be used for preparing red phosphorus flame retardants, organic solvent residues, high polymer materials, volatile organic compounds in materials and the like besides o-benzene. The sampling time is short, and the sampling time of 20 minutes per sample completely meets the requirement of quick screening of enterprise users; direct sample introduction, simple operation, direct solid or liquid sample introduction, five-step operation for making results, and operation by production line workers.

The gas chromatography system consists of an adsorbent contained in a liner 63 of the injector, or a stationary phase of inert solid coated with a liquid and a mobile phase of gas continuously passing through the liner 63. After the sample to be separated and analyzed is added into the liner tube 63 from the top end of the sample injector, because the adsorption or dissolution capacities of the components in the fixed phase sample are different, namely the distribution coefficients of the components between the stationary phase and the mobile phase are different, when the components are repeatedly distributed in the two phases and move forward along with the mobile phase, the moving speeds of the components along the liner tube 63 are different, the time for the components with small distribution coefficients to be retained by the stationary phase is short, and the components can quickly flow out from the tail end of the chromatographic column. The concentrations of the components flowing out of the column ends were plotted against the time after the sample injection, and the resulting graph was called a chromatogram.

Referring to fig. 1 to 4, the split-flow sample injection system of the gas chromatograph includes a sample injector and a control component, the sample injector includes a sample injection housing 50, a supporting frame 60, a clamp 64, a temperature sensor 62, a heating tube 61, a liner tube 63, and a sample filling tube 65, which are sequentially disposed from outside to inside, a thermal insulation isolation structure is disposed in the supporting frame 60 and the sample injection housing 50, the temperature sensor 62 and the heating tube 61 are respectively connected to the control component, and a first through slot is disposed in the liner tube 63.

In this embodiment, by providing the thermal insulation isolation structure between the sample injection housing 50 and the supporting frame 60, the thermal insulation of the objects in the supporting frame 60 can be realized, and the temperature decay rate can be slowed down. In addition, the temperature sensor 62 is arranged to detect the temperature of the heating tube 61 in real time and feed back the temperature to the control component, and the control component adjusts parameters such as heating time and temperature of the heating tube 61 in real time, so that the temperature of the whole system is controlled fully automatically.

In addition, the sample introduction shell 50 is an aluminum alloy section cylinder, plays a role in protecting the fixed top cover 51 and the sealed lower cover 66, and also plays a role in heat preservation and heat insulation.

In an embodiment, the heat insulation structure includes asbestos, and the asbestos is filled between the sample injection housing 50 and the supporting frame 60 to perform the functions of heat insulation.

In one embodiment, referring to fig. 3-4, the temperature sensor 62 is connected to a clamp 64 at an outer end thereof. The clamp 64 can fix the temperature sensor 62 to the heat pipe 61.

In the present embodiment, the temperature sensor 62 is, but not limited to, a K-type thermocouple temperature sensor 62, and the heat pipe 61 is, but not limited to, an MCH cermet heat pipe.

Specifically, the MCH metal ceramic heating tube can realize multi-stage temperature control by a control component through program control, and the temperature rise speed, the constant temperature time and the number of temperature control stages can be set. The temperature is quickly increased and compensated; starting the power of 500W for 20S, and enabling the temperature to reach more than 600 ℃; starting at rated power for 10S to over 200 deg.C.

The K-type thermocouple temperature sensor 62 is a K-type thermocouple with cold end compensation, collects the heating temperature of the MCH cermet heating tube, and has a wide temperature range, high temperature resistance of thousands of degrees centigrade, good durability, and no self-heating.

In addition, the temperature sensor 62 and the heating tube 61 are respectively provided with a lead, the leads are led out from the opening of the top cover 51 of the sample injection shell 50 together, the opening is sealed by high-temperature sealant, and a high-temperature resistant protective sleeve is arranged outside the lead.

In this embodiment, a tapered through slot is further provided in the liner tube 63, the tapered through slot is located below the first through slot, and the first through slot is communicated with the tapered through slot.

In addition, the liner tube 63 is made of quartz glass or a stainless steel tube, a tapered through groove with a small diameter is formed in the lower end in the liner tube 63, the effect of supporting the internal sample filling tube 65 and increasing the contact surface with the sample to ensure complete gasification is achieved, the liner tube 63 is periodically cleaned to prevent pollution, and the liner tube 63 is taken out from the lower end during cleaning.

Preferably, the liner 63 also has embedded therein a sample fill tube 65, the sample fill tube 65 being a quartz glass tube of relatively short length, approximately 1/3 of the liner 63, located in the middle of the liner 63 where the temperature is highest. The sample filling pipe 65 is filled with a mixture of a sample and an inert solid, and the sample is generally an electronic product, plastic, food with pesticide residue, or the like containing harmful substances such as lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyls, polybrominated diphenyl ethers, and the like.

In an embodiment, referring to fig. 3, a top cover 51 is disposed at an upper end of the sample introduction housing 50, a first insert ring is disposed at an upper end of the top cover 51 in an upward protruding manner, a thread is disposed at an outer side of the first insert ring, a lower cover 52 is disposed at a lower end of the sample introduction housing 50, a second insert ring is disposed at the lower cover 52 in a downward protruding manner, and a thread is disposed at an outer side of the second insert ring.

In an embodiment, referring to fig. 4, the periphery of the top cover 51 is connected with the upper sealing cover 40, the upper sealing cover 40 is connected with the top cover 51 through a thread, in addition, a first snap spring 33 is connected between the upper sealing cover 40 and the carrier gas screw 30, an upper metal gasket 41 is connected above the first snap spring 33, the upper metal gasket 41 achieves the purpose of raising the upper sealing cover 40, in addition, the periphery of the upper end of the liner tube 63 is connected with an upper gasket 34, the upper gasket 34 comprises an upper conical graphite pad and a sealing ring sleeve, the sealing ring sleeve is arranged on the liner tube 63 and is close to the upper port of the liner tube 63, the upper gasket 34 achieves the sealing of the liner tube 63, the liner tube 63 is completely sealed, and the components do not pollute the heat pipe 61. Still be provided with sealed graphite packing ring 35 between top cap 51 and the support frame 60, this sealed graphite packing ring 35 and the upper end butt of heating tube 61, go up the toper graphite pad and be pure soft graphite, sealed snare contains the polyimide composite material of graphite such as du pont Vespel SP-21, has added 15% graphite, has high temperature resistant, outstanding elasticity, the advantage of high creep resistance impedance. .

In this embodiment, the top cover 51 and the bottom cover 52 are flanges at two ends of the sample introduction housing 50.

In one embodiment, the lower end of the liner tube 63 is connected with a lower cover gasket at the periphery, the lower cover gasket comprises a lower conical graphite pad 67 and a lower sealing ring sleeve 671, the lower conical graphite pad 67 is made of pure soft graphite, and the lower sealing ring sleeve 671 is made of a graphite-containing polyimide composite material such as Dupont Vespel SP-21, and 15% of graphite is added, so that the high-temperature-resistant, excellent-elasticity and high-creep-resistance liner has the advantages of high temperature resistance, high elasticity and high creep resistance. The lower conical graphite pad 67 is sleeved on the liner tube 63 and is close to the lower port of the liner tube 63, and the upper cover gasket 34 and the lower cover gasket are generally made of graphite pads when the temperature exceeds 400 ℃. The lower cover gasket realizes the sealing of the liner tube 63, the liner tube 63 is completely sealed, and the components can not pollute the heating tube 61. A seal graphite gasket 69 is further provided between the lower cover 52 and the support bracket 60, the seal graphite gasket 69 is in contact with the lower end of the heat generating tube 61, a seal lower cover 66 is screwed to the lower cover 52, a lower metal gasket 78 is connected between the seal lower cover 66 and the lower cover, and the lower metal gasket 78 functions to heighten the seal lower cover 66.

It can be seen that the upper cover gasket 34 and the lower cover gasket achieve sealing of the liner tube 63, the liner tube 63 is completely sealed, and the components do not contaminate the heat generating tube 61.

In an embodiment, referring to fig. 2 to 4, the upper surface of the sample introduction housing 50 is further connected to an upper sample introduction assembly, the upper sample introduction assembly includes a carrier gas pipe 31, a carrier gas valve and a carrier gas screw 30, a carrier gas through groove is formed in the carrier gas screw 30, a second through groove is formed in the carrier gas pipe 31, the second through groove is communicated with the carrier gas through groove, the carrier gas valve is connected to the carrier gas pipe 31, the carrier gas valve is connected to the control assembly, the carrier gas pipe 31 is connected to the sample introduction housing 50, and the first through groove is communicated with the second through groove.

The lower end of the carrier gas screw 30 is embedded in the first insert ring, a hexagonal nut is installed on the outer side of the carrier gas screw 30, and the hexagonal nut is matched with the thread of the first insert ring, so that the carrier gas screw 30 is detachably connected with the sample introduction shell 50.

The carrier gas screw 30 and the carrier gas pipe 31 are welded together by vacuum, and the inner cavity of the carrier gas pipe 31 is communicated with the inner cavity of the carrier gas screw 30. The carrier gas pipe 31 is provided with a carrier gas valve joint nut 32, the carrier gas valve joint nut 32 is connected with a carrier gas valve, the carrier gas valve is positioned in the control box 80, the carrier gas valve comprises a pressure stabilizing valve 86, a fine adjustment valve and a solenoid valve switch, and the carrier gas is generally helium or hydrogen.

In one embodiment, referring to fig. 2 to 4, the sealing upper cover 40 is disposed on the periphery of the carrier gas screw 30, and the first snap spring 33 is connected to the periphery of the carrier gas screw 30, and the sealing upper cover 40 is used for fixing and pressing the carrier gas screw 30, so that the carrier gas screw 30 and the lower conical graphite pad and the sealing ring 68 are tightly pressed to prevent gas leakage. The first latch spring 33 is to prevent the seal cover 40 from falling.

In an embodiment, referring to fig. 2 to 4, the upper end of the carrier gas screw 30 is further connected to a sample inlet 21, a sample inlet is disposed in the sample inlet 21, and a sample inlet isolation pad 22 is disposed between the sample inlet 21 and the carrier gas screw 30.

Preferably, the outer end of the sample inlet member 21 is connected with a sample inlet sealing top cover 23, the upper end of the sample inlet sealing top cover 23 is provided with a clamp spring 20, the upper end of the sample inlet member 21 extends upwards to the upper side of the sample inlet sealing top cover 23, and the clamp spring is connected with the upper end of the sample inlet member 21.

The sample injection sealing top cover 23 is internally provided with a sample injection part 21, the sample injection part 21 is internally provided with a small pinhole and an inverted cone-shaped needle tube guide hole, the inverted cone-shaped needle tube guide hole and the small pinhole can be used for manual injection sample injection or liquid inlet, and an injection needle is pricked into a sample injection isolation pad 22 below during manual injection sample injection. The outside of the sample inlet piece 21 is the clamp spring 20, the sample inlet sealing top cover 23 is uncovered before the sample is used, a solid sample is placed in the middle of the quartz tube, two ends of the solid sample are fixed by quartz cotton, the prepared sample small tube is clamped by tweezers or hooked by a hook in a liner tube 63 placed in a sample inlet device, then the sample inlet sealing top cover 23 is screwed up until the sample inlet sealing top cover 23 is screwed up, at the moment, the sample inlet piece 21 and the sample inlet isolation pad 22 below the sample inlet sealing top cover can not rotate together with the sample inlet sealing top cover 23, and the sample inlet isolation pad 22 is prevented from being abraded.

Specifically, the sample isolation pad 22 is, but not limited to, a graphite pad, a high temperature resistant silicone rubber pad with a teflon film on the pad, or a polyimide composite material containing graphite, such as dupont Vespel SP-21, with 15% graphite added, and has the advantages of high temperature resistance, excellent elasticity, and high creep resistance. The sample to be analyzed is prevented from being polluted by keeping the temperature as low as possible or keeping the temperature far away from the heating element during operation.

In an embodiment, referring to fig. 2 to 4, the lower end of the sample injection housing 50 is connected to a lower sample injection assembly, the lower sample injection assembly includes a lower sample injection tube 70, a shunt tube 77 and a shunt valve, a lower sample injection through slot is disposed in the lower sample injection tube 70, a third through slot is disposed in the shunt tube 77, the lower sample injection through slot is respectively communicated with the conical through slot and the third through slot, and the shunt tube 77 is connected to the shunt valve. The shunt tube 77 is arranged at the lower end, the liner tube 63 is completely sealed, the components can not pollute the heating tube 61, and the temperature control cracking and shunt integrated control can be realized.

The lower sampling pipe 70 is welded with a shunt pipe 77, the shunt pipe 77 is provided with a shunt valve joint screw cap 71, the shunt valve is positioned in the control box 80, and the shunt valve comprises a three-way switching valve, a solenoid valve switch and a needle valve.

In an embodiment, referring to fig. 2 to 4, a sample injection needle 75 is further connected to a lower portion of the lower sample injection tube 70, a fourth through slot is disposed in the sample injection needle 75, and the fourth through slot is communicated with the lower sample injection through slot.

In this embodiment, referring to fig. 2, 3 and 4, a sample needle pad 74 is disposed at an upper end of the sample needle 75. The sample injection needle pad 74 is a tapered sealing pad, and wraps the sample injection needle 75, and the material is the same as that of the sealing pad. The split gas enters the inlet of the GC gas chromatograph through the injection needle 75. The carrier gas and the sample gas are divided into two parts with greatly different flow rates according to a proportion, wherein the part with the smaller flow rate enters a capillary column of the gas chromatograph through a sample injection needle 75, and the part with the larger flow rate is discharged from a dividing pipe 77. The lower end of the sample injection needle pad 74 is provided with a sample injection sealing pad 76, in this embodiment, the sample injection sealing pad 76 is a gasket, and the material of the sample injection sealing pad 7 is the same as that of the gasket.

In addition, a conical graphite pad 67 is arranged between the lower sample injection tube 70 and the lower end of the liner tube 63, a lower sealing washer 671 is arranged at the lower end of the conical graphite pad 67, a sealing washer 69 is arranged between the lower end of the heating tube 61 and the lower cover 52 of the sample injection shell 50 and is made of pure soft graphite, and the upper and lower parts of the graphite sealing washer 69 are respectively provided with a piece and are tightly attached to the upper and lower ends of the heating tube 61 to prevent air leakage from polluting the wall of the heating tube 61. The tapered graphite pad 67 fits snugly against the liner tube 63 and operates to keep the temperature as low as possible or away from the heating element. The temperature is over 400 ℃ and is generally supported by a graphite gasket, the lower sealing gasket 671 can be a polytetrafluoroethylene high-temperature-resistant silicon rubber gasket, a graphite-containing polyimide resin composite material such as DuPont Vespel SP-21, 15% of graphite is added, and the high-temperature-resistant and high-elasticity graphite-resistant composite gasket has the advantages of high temperature resistance, excellent elasticity and high creep resistance.

In an embodiment, referring to fig. 2 to 4, the sealing lower cover 66 is connected to an outer side of the lower sample inlet tube 70, the sealing lower cover 66 is connected to a lower end of the sample inlet housing 50, a sample inlet sealing cover 72 is connected to an outer side of the sample inlet 75, and a sample inlet supporting column 73 is connected to an outer side of the sample inlet sealing cover 72.

Preferably, the holder 10 is disposed on the outer side of the sample injection housing 50, and the holder 10 such as a metal cover is fixed to the sample injection housing 50 to support and protect the sample injection needle 75.

In an embodiment, referring to fig. 5, the control assembly includes a control box 80, a temperature controller, a circuit board, a power supply, a first solenoid valve switch and a second solenoid valve switch, the first solenoid valve switch is connected to the carrier gas valve, the second solenoid valve switch is connected to the flow dividing valve, the first solenoid valve switch, the second solenoid valve switch and the temperature controller are respectively connected to the circuit board, the power supply is connected to the circuit board, the first solenoid valve switch, the second solenoid valve switch, the temperature controller, the circuit board and the power supply are respectively disposed in the control box 80, in addition, the carrier gas valve and the flow dividing valve are also connected to the control box 80, and the temperature controller can be used for setting a temperature control curve program temperature rise and a temperature control range by a computer: 50-450 ℃, and generally applied at a temperature of less than 400 ℃. The temperature of the thermal cracking program is raised to 200-450 ℃ for 2 min. The carrier gas valve includes a solenoid valve, a surge valve 86, and a trim valve.

The circuit board comprises an MCU, a power heating driving circuit, a temperature sensor 62, a power heating driving circuit, a carrier gas valve, a heating tube 61 and a temperature controller which are respectively connected with the MCU, and the power supply is but not limited to a power switch power supply.

In addition, the control box 80 is further provided with a plurality of air passage adapters 84, a 5PIN air connector 83, a power socket 82 and a USB socket 81.

Specifically, the above-mentioned flow dividing valve includes a solenoid valve, a three-way valve, and a needle valve 87. The control box 80 is also provided with a fine adjustment valve 85.

The system sets the flow dividing proportion or non-flow dividing and the valve opening and closing time by a program. The front pressure regulating valve of the chromatographic column is arranged on the flow dividing gas path, so that the front pressure of the chromatographic column can be changed under the condition of constant total flow. The higher the column front pressure, the higher the column flow rate, and the faster the analysis rate. And if the flow dividing ratio is to be changed under the condition that the pressure in front of the column is not changed, namely the flow rate of the column is not changed, the total flow is adjusted, and the larger the total flow is, the larger the flow dividing ratio is. For example, when the flow rate of the split stream is 100mL/min and the flow rate in the column is lml/min, the split ratio is 100: 1.

The temperature control process of the whole system adopts proportional, integral and differential PID temperature control algorithm. The program realizes automatic temperature control through presetting PID parameters of a temperature control curve. The temperature sensor 62 is a K-type thermocouple and is connected to the MCU through a cold end compensated thermocouple digitizer dedicated IC, in which a local temperature sensor, a precision amplifier, an ADC and a voltage reference are integrated, and thermocouple signals can be digitized. The heating tube 61 is driven by the heating power NMOS tube driven by the PWM signal output by the MCU to control the heating time and the current. Typical temperature control process: and (3) raising the temperature of the o-benzene analysis program to 50 ℃ for 1min, raising the temperature to 450 ℃ at a rate of 20 ℃ per minute and maintaining for 4min, and automatically drawing a peak spectrogram by a GC (gas chromatography) workstation. The whole system has high automation degree, good and fast atlas analyzing effect, simple structure, simple and convenient operation and high cost performance.

The utility model provides an foretell gas chromatograph reposition of redundant personnel sampling system, through setting up injector and control assembly, the injector includes from outer to interior injection shell 50 that sets gradually, support frame 60, clamp 64, temperature sensor 62, heating tube 61, bushing pipe 63 and sample filling tube 65, and be equipped with the isolation structure that keeps warm in support frame 60 and injection shell 50, bushing pipe 63 is totally enclosed, the component can not pollute heating tube 61, but realize full automatic control temperature, set up the thermal-insulated structure that keeps warm, reduce temperature attenuation degree.

In an embodiment, there is also provided a working method of a split-flow sample injection system of a gas chromatograph, including:

the control component controls the heating time and temperature of the heating tube 61 according to the preset temperature control curve PID parameters, the detected temperature is transmitted to the control component by the temperature sensor 62 in real time, and the heating time and temperature of the heating tube 61 are adjusted by the control component. The control component sets the flow distribution proportion or does not flow distribution through a program and realizes flow distribution and sample introduction control through the opening and closing time of the first electromagnetic valve switch and the second electromagnetic valve switch.

It should be noted that, as can be clearly understood by those skilled in the art, the specific implementation process of the working method of the split sampling system of the gas chromatograph may refer to the corresponding description in the embodiment of the split sampling system of the gas chromatograph, and for convenience and brevity of description, no further description is given here.

The technical contents of the present invention are further illustrated by the examples only for the convenience of the reader, but the embodiments of the present invention are not limited thereto, and any technical extension or re-creation based on the present invention is protected by the present invention. The protection scope of the invention is subject to the claims.