Ventilation box of liquid chromatograph

Abstract

The utility model aims to provide a liquid chromatograph ventilation box. The liquid chromatograph ventilation box comprises a ventilation box body, a ventilation box door, a ventilation box door baffle plate, a door hinge, an air supplementing port baffle plate, an air supplementing port baffle plate hole, an air supplementing port hole, a waste liquid pipe penetrating plate pagoda joint, an exhaust port flange and an air volume adjusting valve, through the exhaust system of the laboratory, an air pressure difference is formed between the liquid chromatograph ventilation box and the outside, so that organic gases volatilized from solvents in the mobile phase bottle and the waste liquid bottle are all collected in the liquid chromatograph ventilation box and are sucked into the exhaust pipeline and do not overflow to the outside, thereby solving the pollution of the volatilization of the organic solvents to the laboratory; and the body health of inspection personnel is effectively protected. The ventilation box of the liquid chromatograph is small in size, volatile gas does not overflow out of the box body, only an extremely small exhaust air rate is needed, the influence on the indoor temperature is extremely small, meanwhile, the emission of laboratory air after temperature treatment is reduced, and an energy-saving effect is achieved. The ventilation box of the liquid chromatograph is not only suitable for the liquid chromatograph, but also suitable for other instruments needing mobile phases. The ventilation box of the liquid chromatograph is made of transparent polymer plates, materials are easy to obtain, the structure is simple, and batch production is facilitated.

Description

Technical Field

[0001] The utility model relates to ventilation equipment for a chemical laboratory, in particular to a ventilation box for a liquid chromatograph. Background Art

[0002] Liquid chromatographs are commonly used in chemical laboratories. Using a buffered solution or organic solvent as the mobile phase, they produce waste liquids that are discharged from the instrument and stored in waste containers. Organic solvents, such as methanol and acetonitrile, are often volatile and toxic, and their volatiles can pose health risks to testers. Promptly and efficiently discharging volatile gases from the mobile phase and waste liquids from the laboratory is a key protective measure in chemical laboratories.

[0003] At present, the common method used in liquid phase laboratories is to exhaust volatile gases by connecting a universal joint exhaust hood to the laboratory ventilation duct. The universal joint exhaust hood is an open hemispherical hood placed above the liquid chromatograph mobile phase bottle. It dilutes the concentration of volatile gases in the laboratory solvent through large exhaust volume and high air exchange rate to reduce pollution. The exhaust volume of each universal joint exhaust hood is required to be 200-400m 3 / h.

[0004] Some detectors in liquid chromatographs are sensitive to temperature fluctuations, particularly differential refractive index detectors. Temperature fluctuations can significantly impact test data. Liquid chromatography laboratories often house multiple LC instruments, resulting in significant total exhaust volumes, which can cause temperature fluctuations within the laboratory. This can affect the accuracy of test data if sensitive detectors, such as differential refractive index detectors, are present. Furthermore, in laboratories requiring temperature control, this can lead to the exhaust of large quantities of cooling or heating air, resulting in significant energy losses and incompatible with energy conservation.

[0005] Currently, other solutions involve adding air to the mobile phase bottle. Using a one-way valve cap effectively solves the problem of mobile phase bottle volatilization. Waste liquid bottles release gas, and using an adsorbent cap to absorb the leaked organic gas is crucial. However, a single adsorbent has varying adsorption efficiencies for different organic compounds. For example, the saturated adsorption capacity of activated carbon for methanol is 10%. Adsorption efficiency is limited by saturation time, and adsorbents generally desorb. Therefore, adsorbent caps cannot guarantee high adsorption efficiency for all volatile organic reagent gases.

[0006] The purpose of this utility model is to minimize the pollution caused by the volatilization of mobile phase and waste liquid to the experiment, while reducing the exhaust volume and air exchange rate to minimize the impact of laboratory temperature fluctuations on experimental accuracy. Utility Model Content

[0007] The purpose of this utility model is to provide a fume hood for liquid chromatographs. By utilizing the laboratory's own exhaust system, a pressure differential is created between the fume hood and the outside world. This allows organic gases volatilized from solvents in mobile phase bottles and waste liquid bottles to be collected within the fume hood and drawn into an exhaust duct, preventing them from escaping to the outside. This prevents laboratory contamination caused by organic solvent volatilization. The fume hood for liquid chromatographs of this utility model is compact, requiring only a minimal exhaust volume to prevent the escape of volatile gases. This minimal exhaust volume also minimizes the impact of the ambient temperature on the laboratory environment.

[0008] The technical solutions provided by this utility model are as follows:

[0009] The liquid chromatograph fume hood of the utility model comprises a fume hood body, a fume hood door, a fume hood door baffle, a door hinge, an air supply port baffle, an air supply port baffle hole, an air supply port hole, a waste liquid pipe through-plate pagoda joint, an exhaust port flange, and an air volume regulating valve.

[0010] The ventilation box body is a transparent rectangular parallelepiped, and the ventilation box door is a double-door in front of the ventilation box body, fixed to the ventilation box body by the door hinge, and the ventilation box door baffle is on the inner side of the ventilation box door when it is closed; the air supply inlet hole is an opening on the two side panels of the ventilation box body, and the air supply inlet baffle is outside the air supply inlet hole, and the air supply inlet baffle hole is an opening on the air supply inlet baffle, and the position and size correspond to the air supply inlet hole; the exhaust outlet flange is located in the upper right corner of the rear panel of the ventilation box body, and the installation position is on the rear panel of the ventilation box according to the inner diameter of the flange; the air volume regulating valve is connected to the exhaust outlet flange; the waste liquid pipe through-plate pagoda joint is located on the rear panel of the ventilation box.

[0011] Preferably, the ventilation box body and the ventilation box door are made of transparent polymer sheets with a thickness of 5 mm;

[0012] Preferably, the length and width of the fume hood are suitable for the size of the mobile phase tray at the top of the liquid chromatograph, and the height is 400 mm;

[0013] Preferably, the ventilation box door is a double-door;

[0014] Preferably, the door hinge is a stainless steel hinge or an injection-molded hinge;

[0015] Preferably, the air supply holes are located on both sides of the ventilation box body, with 3 holes on each side and a diameter of 20 mm. The air supply baffle holes are holes opened on the air supply baffle, corresponding to the position and size of the air supply holes;

[0016] Preferably, when the air supply port baffle and the air supply port hole are installed, a 5mm spacer is added to leave a 5mm gap between the two.

[0017] Preferably, primary-effect cotton is stuffed between the air supply port baffle and the air supply port hole and replaced regularly;

[0018] Preferably, the exhaust flange is Specifications of injection molding flange;

[0019] Preferably, the air volume regulating valve adopts Specifications of plastic air volume regulating valve;

[0020] Preferably, the waste liquid pipe through-plate pagoda connector is a plastic through-plate pagoda connector with an outer diameter of 10 mm;

[0021] By adopting the above technical solution, the beneficial effects of the utility model are:

[0022] 1. The fume hood of this liquid chromatograph is connected to the laboratory exhaust system. When in use, the door of the hood is closed to form a slightly negative pressure relative to the laboratory air pressure. The mobile phase bottle is placed inside to reduce the risk of volatile gas from organic reagents overflowing.

[0023] 2. The filter air supply holes of the mobile phase fume hood replenish filtered air into the box, reducing dust contamination of the mobile phase and preventing the fume hood door from being difficult to open when the mobile phase fume hood is in a negative pressure state. It is also used as a channel for the mobile phase supply pipe.

[0024] 3. The fume hood of the liquid chromatograph is connected to the waste liquid bottle through the waste liquid bottle exhaust pipe. The organic gas volatilized from the waste liquid bottle enters the fume hood of the liquid chromatograph along the waste liquid bottle exhaust pipe and is finally discharged from the laboratory through the laboratory exhaust duct.

[0025] 4. The transparent fume hood material makes it easy to observe the amount of mobile phase used and the mobile phase label;

[0026] 5. The exhaust air volume of the liquid chromatograph fume hood is small and adjustable, which ensures the discharge of volatile gases while maintaining a low air exchange rate in the laboratory and reducing laboratory temperature fluctuations.

[0027] 6. Compared with each mobile phase bottle that must have a mobile phase solvent bottle one-way valve bottle cap, and compared with the waste liquid bottle activated carbon bottle cap, this liquid chromatograph exhaust box discharges pollutants more thoroughly and more efficiently.

[0028] 7. This liquid chromatograph fume hood is not only suitable for liquid chromatographs, but also for two-dimensional liquid chromatography, liquid chromatography-mass spectrometry and other instruments that require mobile phase.

[0029] 8. The fume hood of this liquid chromatograph can be made of transparent acrylic, polypropylene PP or polyvinyl chloride PVC and other materials. The materials are easy to obtain and can be produced by bonding, welding, injection molding. The structure is simple and easy to mass produce. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for the technical description of the present invention. The drawings are an integral part of the specification and, together with the following instructions, are used to explain and further understand the present invention, but do not constitute a limitation of the present invention. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without inventive work.

[0031] In the attached figure:

[0032] Figure 1 A front view of the fume hood for a liquid chromatograph according to the present invention;

[0033] Figure 2 A side view of the fume hood of a liquid chromatograph according to the present invention;

[0034] Figure 3 A top view of the ventilation box of a liquid chromatograph described in the present invention.

[0035] Description of reference numerals:

[0036] The liquid chromatograph fume hood described in the present invention includes: a fume hood body ①, a fume hood door ②, a fume hood door baffle ③, a door hinge ④, an air supply port baffle ⑤, an air supply port ⑥, an air supply port baffle hole ⑦, an air volume regulating valve ⑧, an exhaust port flange ⑨, and a waste liquid pipe through-plate pagoda joint ⑩. DETAILED DESCRIPTION

[0037] Chemical laboratories use a variety of chemical reagents that volatilize and produce toxic, harmful, corrosive, irritating, and odorous gases. Therefore, exhaust systems consisting of exhaust fans, activated carbon adsorption boxes or acid mist neutralization towers, exhaust ducts, fume hoods, and exhaust hoods are essential protective measures. This utility model considers this to be a common laboratory practice.

[0038] The following will fully describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. In the present invention, unless otherwise clearly specified and limited, the terms "upper", "lower", "inside", "outside" and the like indicate directions and relative position relationships. They are based on the directions and relative position relationships in the drawings or actual operations, and are only for the convenience of describing the present invention and cannot be understood as limitations on the present invention.

[0039] The liquid chromatograph fume hood described in the present invention, the fume hood box body ①, can be assembled with materials such as transparent acrylic plate, polypropylene PP or polyvinyl chloride PVC. The present invention uses acrylic as an example for explanation. The transparent material makes it easy to observe the mobile phase label and usage amount inside the fume hood box body ①.

[0040] The ventilation box door ② is a double-leaf door, which is half the width of a single-leaf door. When the door is opened, the torque generated is small and symmetrical on both sides. Compared with a single-leaf door, the torque generated is large and the impact on the stability of the box is small on one side. The ventilation box door baffle ③ is fixed on the inside of the closed ventilation box door ② to prevent the ventilation box door ② from sinking inward and causing the gap to be too large.

[0041] The bottom size of the fume box body ① is adapted to the mobile phase bottle tray on the liquid chromatograph. It is placed on the liquid chromatograph. The air volume regulating valve ⑧ is installed on the exhaust flange ⑨ at the rear side of the fume box body ①. One end of the telescopic aluminum foil tube is connected to the air volume control valve ⑧ on the rear plate of the fume hood body ①, and the other end is connected to the laboratory ventilation duct. The unfolded length of the telescopic aluminum foil tube is not less than 2m, which is convenient for adjusting the position of the liquid chromatograph.

[0042] Take a 10cm long and 1cm wide paper strip and hang it inside the air supply port ⑥. Close the ventilation box door ② and adjust the air volume control valve ⑧. The paper strip is slightly blown up by the air flow from the air supply port ⑥. Open the ventilation box door ② and air flows in from the door direction. The paper strip droops, indicating that when the ventilation box door ② is closed, a pressure difference is formed between the inside and outside of the box, and the volatile gas will not overflow the box. At this time, the wind speed at the inner opening of the exhaust vent flange ⑨ measured by the anemometer is 0.2m / s. The calculated exhaust volume of the pipeline is 3.2m 3 / h.

[0043] One end of the waste liquid exhaust pipe is connected to the waste liquid bottle cap, and the other end is connected to the waste liquid pipe through-plate pagoda joint ⑩. With this arrangement, the organic gas volatilized from the waste liquid bottle enters the ventilation box body ① along the waste liquid exhaust pipe and is discharged into the ventilation duct through the exhaust outlet flange ⑨.

[0044] Supply air inlet ⑥ consists of three 20mm diameter holes located on the two side panels, arranged horizontally with a 20mm gap between each hole. The filter supply air inlet baffle ⑤ is located outside supply air inlet ⑥, with a 5mm gap between them. Supply air inlet baffle hole ⑦ is located on the filter supply air inlet baffle ⑤, at the same location as supply air inlet ⑥, one on each side of the fume hood body ②. Primary cotton is inserted between supply air inlet baffle ⑤ and supply air inlet ⑥. One end of the mobile phase supply tube is connected to the liquid chromatograph, and the other end passes through the 5mm gap between supply air inlet baffle ⑤ and supply air inlet ⑥, through supply air inlet ⑥, and into the bottom of the mobile phase bottle. This arrangement, firstly, prevents the exhaust door ① from being difficult to open when under negative pressure; secondly, the air entering the mobile phase exhaust box is filtered, reducing dust contamination of the mobile phase; and thirdly, it serves as a channel for the mobile phase supply tube.

[0045] The utility model liquid chromatograph fume hood maintains a pressure difference between the inside and outside of the hood under the action of the laboratory exhaust system. While ensuring that the volatile gas from the mobile phase bottle and the waste liquid bottle does not overflow outside the hood, the required exhaust volume is only 2% of the nominal value of the universal joint exhaust hood exhaust volume, greatly reducing the impact of exhaust on the indoor temperature.

[0046] When the mobile phase and waste liquid bottles are replaced, volatile gases overflow and pollute the laboratory air. If the laboratory needs a larger exhaust, the air volume regulating valve ⑧ can be adjusted to the maximum and the door of the fume hood can be opened. A larger ventilation rate can still be obtained to exhaust the polluted air in the laboratory. That is, the exhaust volume can be controlled according to needs.

[0047] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made based on the description and drawings of the present invention, or only material changes, directly or indirectly used in other related technical fields under the inventive concept of the present invention are included in the patent protection scope of the present invention.

Claims

1. Liquid chromatograph fume hood, characterized by: The ventilating inlet is provided with a through hole, and the through hole is provided with a through hole.

2. The liquid chromatograph fume hood according to claim 1, characterized in that: The ventilation box body and the ventilation box door are made of transparent polymer plates with a thickness of 5 mm. The length and width of the ventilation box body are suitable for the size of the mobile phase tray at the upper end of the liquid chromatograph, and the height is 400 mm. The ventilation box door is a double door, and the door hinges are made of stainless steel hinges or injection molded hinges.

3. The liquid chromatograph fume hood according to claim 1, characterized in that: The air supply holes are located on both sides of the ventilation box body and are symmetrical, with 3 holes on each side, a diameter of 20mm, arranged horizontally, and a spacing of 20mm between the holes. The air supply baffle holes are holes opened on the air supply baffle, corresponding to the position and size of the air supply holes. When the air supply baffle and the air supply hole are installed, a 5mm pad is added to leave a 5mm gap between the two. Primary-effect cotton is stuffed between the air supply baffle and the air supply hole.

4. The liquid chromatograph fume hood according to claim 1, characterized in that: The exhaust flange adopts Specifications of injection molding flange, the air volume control valve adopts The waste liquid pipe through-plate pagoda joint is a plastic through-plate pagoda joint with an outer diameter of 10 mm.

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