Sulfurous acid on-line analyzer

Abstract

The utility model discloses a sulfurous acid on-line analyzer which comprises a main cabinet body and a circulating sampler, and the main cabinet body is provided with an analyzer host, a pure water module, a positive pressure protection device and an explosion-proof junction box; a luminosity detector, a feeding pump, a discharging pump, a hydrochloric acid pump, a starch reagent pump, a plunger pump and a pure water pump which are connected and communicated with the luminosity detector through a hose, and a pure water valve connected and communicated with the pure water pump are arranged at the lower part in the analyzer host, the pure water valve is connected and communicated with a pure water module, and the luminosity detector comprises a luminosity detection assembly and an analysis cup; according to the utility model, the luminosity detector, the feeding pump, the discharging pump, the hydrochloric acid pump, the starch reagent pump, the plunger pump, the pure water pump and the pure water valve are combined to form a feeding system, a sample replacement system, a hydrochloric acid supply system, a starch reagent supply system, an iodine solution dropwise adding system and a cleaning system; the whole sulfurous acid on-line analyzer can realize continuous on-line analysis, and the working efficiency and accuracy of the analyzer can be improved.

Description

Technical Field

[0001] The utility model relates to the field of chemical analysis equipment, in particular to an online sulfurous acid analyzer. Background Art

[0002] Corn soaking is one of the steps in the wet milling process to produce starch. Therefore, sulfurous acid is generally added to the corn soaking solution. This is mainly because sulfurous acid itself has a certain bactericidal effect and can prevent the corruption of organic matter. At the same time, sulfurous acid will destroy the protein network structure of corn particles. Sulfous acid can react with protein groups to generate protein thiosulfate. This salt solution is easily soluble in water and can diffuse into the soaking solution. The presence of sulfurous acid will accelerate the absorption of water by corn and increase the starch output rate. At the same time, the addition of sulfurous acid can change the protein network structure and catalyze the formation of pore structure. This structure can effectively separate starch from protein structure. It is beneficial to the removal of starch molecules. However, when using sulfurous acid, you should also pay attention to the volatility of sulfurous acid. It is easy to emit sulfur dioxide. Sulfur dioxide has a certain acidity and is harmful to human health after inhalation. It is also corrosive to the equipment. Therefore, the mass percentage concentration of sulfurous acid used in the soaking solution is generally controlled at 0.25%-0.3%. After soaking, the solution needs to be tested for the content of sulfurous acid. At this time, the content of sulfurous acid is generally required to be controlled at 0.1g-0.3g / 100ml. Too low concentration will make the bleaching, antibacterial and dissolving of non-starch substances of sulfurous acid worse. Too high concentration will easily destroy nutrients and cause certain corrosion to the equipment.

[0003] In this process, the content of sulfurous acid in the soaking liquid needs to be detected at regular intervals (about half an hour) to ensure the normal production and to protect the health and safety of operators. Traditionally, manual titration is mostly used, which requires frequent sampling, which is not only time-consuming and labor-intensive, but also has low accuracy in the test results. In addition, manual sampling is required all the time, which is a large workload. There are also online sulfurous acid analyzers, in which the reaction cup and the detector are integrated together. After the sample is extracted and mixed with hydrochloric acid, starch reagent and iodine solution, the liquid produced will adhere to the wall of the reaction cup. The detection cup is not easy to clean after long-term use. The detector is a photometric detector. The light transmittance of the reaction cup that has not been thoroughly cleaned will be reduced, thereby affecting the accuracy of the test results. Frequent disassembly of the detection cup for cleaning is likely to affect the efficiency of the test, which is not conducive to continuous online analysis of the equipment. Utility Model Content

[0004] In view of the deficiencies in the prior art, the purpose of the utility model is to provide an online sulfurous acid analyzer which has a simple structure, can perform full-automatic detection, is easy to operate and maintain, and can improve work efficiency and accuracy.

[0005] The technical solution adopted by the utility model to solve its technical problems is:

[0006] A sulfite online analyzer comprises a main cabinet, a circulation sampler arranged outside the main cabinet, an analyzer host, a pure water module and a positive pressure protection device are installed inside the main cabinet, and an explosion-proof junction box is installed outside the main cabinet; a photometric detector is installed at the lower part of the analyzer host, a feed pump, a discharge pump, a hydrochloric acid pump, a starch reagent pump, a plunger pump, a pure water pump are connected to the photometric detector through a hose, and a pure water valve is connected to the pure water pump; an electric control system for controlling the photometric detector, the feed pump, the discharge pump, the hydrochloric acid pump, the starch reagent pump, the plunger pump, the pure water pump and the pure water valve is also installed at the upper part of the analyzer host, the pure water valve is connected to the pure water module, the photometric detector comprises a photometric detection component, and an analysis cup inserted in the photometric detection component and specifically connected to the feed pump, the discharge pump, the hydrochloric acid pump, the starch reagent pump, the plunger pump and the pure water pump.

[0007] Preferably, the photometric detection assembly includes a photometric detector housing, a photometric detection inner box assembled at the lower end of the photometric detector housing, the photometric detection inner box including a box body, a through-wall wiring terminal fixed to the lower end of the inner side of the box body by screws, photosensitive semiconductor components and light-emitting diodes fixedly installed at the lower end of the inner side of the box body and arranged relatively to each other, an inner box bottom plate fixedly installed below the box body, a motor placed in the center above the inner box bottom plate, a pressure plate placed above the motor and connected to the inner box bottom plate by screws to fix the motor, and a magnetic stirring seat fixedly installed on the output end of the motor, the through-wall wiring terminals simultaneously connecting the photosensitive semiconductor components, the light-emitting diode and the motor through wires.

[0008] Preferably, the analysis cup comprises a cup body with a large diameter at the upper end and a small diameter at the lower end, a cup cover mounted on the upper part of the cup body and provided with a plurality of threaded holes, an O-ring mounted at the lower end of the cup cover for improving the sealing performance between the cup body and the cup cover, a plurality of external threaded straight joints screwed into the threaded holes of the cup cover and a flanged joint for connecting a pipe at the discharge end of a plunger pump, a magnetic stirrer placed at the bottom of the cup body, a discharge pipe close to the bottom of the cup body, a feed pipe shorter than the discharge pipe, a hydrochloric acid reagent tube shorter than the feed pipe, a starch reagent tube of the same length as the hydrochloric acid reagent tube, a pure water tube and an iodine solution dripping tube, and a hydrochloric acid reagent tube. The lower ends of the reagent tube, starch reagent tube, pure water tube and iodine solution dripping tube located in the cup body all exceed the depth of the part with a larger diameter at the upper end of the cup body. The discharge pipe, feed pipe, hydrochloric acid reagent tube, starch reagent tube and pure water tube are respectively connected and fixed with the corresponding external threaded straight-through joints, and then the feed pipe is connected to the feed pump, the discharge pipe is connected to the discharge pump, the hydrochloric acid reagent tube is connected to the hydrochloric acid pump, the starch reagent tube is connected to the starch reagent pump, and the pure water pipe is connected to the pure water pump through the external threaded straight-through joint. The iodine solution dripping tube is connected and fixed with the flanging joint, and then the iodine solution dripping tube is connected to the pipeline at the discharge end of the plunger pump through the flanging joint.

[0009] Furthermore, the cup cover is also provided with a cup body drain port, which is one of the external threaded straight-through connectors, and the cup body drain port is connected to the outside of the analyzer host through a pipeline.

[0010] Preferably, the circulating sampler, the photometric detector and the feed pump are sequentially connected through pipelines to form a sample feeding system, the input end of the feed pump is connected to the circulating sampler, and the output end of the feed pump is connected to the analysis cup of the photometric detector.

[0011] Preferably, the photometric detector, feed pump and discharge pump are connected through pipelines to form a sample replacement system, the input end of the discharge pump is connected to the analysis cup of the photometric detector, and the output end of the discharge pump is extended to the outside of the main cabinet through a pipe system.

[0012] Preferably, the hydrochloric acid pump, starch reagent pump, plunger pump and photometric detector are connected through pipelines to form a hydrochloric acid supply system, a starch reagent supply system and an iodine solution dropping system respectively.

[0013] Preferably, the photometric detector, the feed pump, the discharge pump and the pure water pump are connected through pipelines to form a cleaning system, and the output end of the pure water pump is connected to the photometric detector.

[0014] Preferably, the starch reagent pump is a peristaltic pump.

[0015] Preferably, the positive pressure protection device includes a pressure reducing valve and a flow meter;

[0016] The electric control system includes a touch screen, a power module, a wiring board, a main control board, and a PLC controller. The touch screen is arranged on the front panel of the analyzer host. The power module, the wiring board, the main control board, and the PLC controller are arranged behind the touch screen. A power switch and a USB interface are arranged on the front panel of the analyzer host beside the touch screen. The explosion-proof junction box is connected to the power module through the wiring board of the electric control system via a cable;

[0017] The lower part of the circulating sampler is provided with a circulating sampler inlet connected to a circulation pool in which a sample circulates, the upper part of the circulating sampler is provided with a circulating sampler outlet, and the circulating sampler is provided with a filter membrane tube for filtering impurities and bubbles, the lower end of the filter membrane tube is close to the circulating sampler inlet, and the upper end of the filter membrane tube is far away from the circulating sampler inlet and is connected to the input end of the feed pump through a pipeline.

[0018] The beneficial effects of the utility model are as follows: the utility model adopts photometric titration, and forms a feeding system, a sample replacement system, a hydrochloric acid supply system, a starch reagent supply system, an iodine solution dropping system and a cleaning system through a photometric detector, a feed pump, a discharge pump, a hydrochloric acid pump, a starch reagent pump, a plunger pump, a pure water pump and a pure water valve, so that the entire sulfurous acid online analyzer can realize continuous and uninterrupted online analysis. The analysis cup body with a large diameter at the upper end and a small diameter at the lower end comprehensively considers the factors of capacity and optical path. The large diameter at the upper end can make the cup body accommodate more detection liquid, that is, material, to meet the requirements of the detection sampling amount, and prevent the small sampling amount from affecting the detection result. The small diameter at the lower end makes the diameter of the small diameter cup body smaller than the optical path, ensuring that light can pass through the cup body, and ensuring the progress and accuracy of the detection. The magnetic stirring seat and the magnetic The stirring bar can ensure the uniformity of the test liquid composition in the cup body and the accuracy of the detection. The detection accuracy can be controlled within 1%, which can improve the working efficiency and accuracy of the analyzer. The positive pressure system can maintain the positive pressure in the main cabinet to prevent the instrument from being corroded. The continuous sampler can continuously sample from the production pipeline to ensure the consistency of the composition of the test liquid and the liquid in the production pipeline, and at the same time filter out impurities and bubbles in the test liquid to further improve the accuracy of the detection. The setting of the pure water pump can realize automatic cleaning, which is convenient and fast. The pure water module, the analyzer host, and the photometric detector in the analyzer host are scientifically designed and reasonably laid out, especially the structure of the photometric detector housing, the photometric detection inner box, etc., which is compact, reduces the occupied space of the analyzer, is convenient and flexible, and increases the scope of application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of a sulfurous acid online analyzer according to this embodiment;

[0020] Figure 2 for Figure 1The structural diagram of the analyzer host connected to the circulating sampler;

[0021] Figure 3 for Figure 2 Structural diagram of the mesophotometer;

[0022] Figure 4 for Figure 3 Exploded view of the mid-light detection assembly;

[0023] Figure 5 for Figure 4 Exploded view of the inner box for medium light detection;

[0024] Figure 6 for Figure 1 Exploded view of the medium analysis cup;

[0025] Figure 7 for Figure 1 Schematic diagram of the structure of the medium-circulation sampler. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0027] Example

[0028] like Figure 1-7 As shown, a sulfurous acid online analyzer comprises a main cabinet 1, a circulating sampler 2 arranged outside the main cabinet 1, an analyzer host 11, a pure water module 12 and a positive pressure protection device 13 are installed inside the main cabinet 1, and an explosion-proof junction box 14 is installed outside the main cabinet 1; a photometric detector 111 is installed at the lower part of the analyzer host 11, a feed pump 112, a discharge pump 113, a hydrochloric acid pump 114, a starch reagent pump 115, a plunger pump 116, a pure water pump 117 connected to the photometric detector 111 through a hose, and a pure water valve 118 connected to the pure water pump 117 is connected to the analyzer. An electronic control system 119 for controlling a photometric detector 111, a feed pump 112, a discharge pump 113, a hydrochloric acid pump 114, a starch reagent pump 115, a plunger pump 116, a pure water pump 117, and a pure water valve 118 is also installed on the upper part of the interior of the instrument main unit 11. The pure water valve 118 is connected to the pure water module 12. The photometric detector 111 includes a photometric detection component 1111, and an analysis cup 1112 which is inserted into the photometric detection component 1111 and is specifically connected to the feed pump 112, the discharge pump 113, the hydrochloric acid pump 114, the starch reagent pump 115, the plunger pump 116, and the pure water pump 117.

[0029] The electronic control system 119 includes a touch screen, a power module, a wiring board, a main control board, and a PLC controller. The touch screen is arranged on the front panel of the analyzer host. The power module, the wiring board, the main control board, and the PLC controller are arranged behind the touch screen. A power switch and a USB interface are arranged on the front panel of the analyzer host next to the touch screen.

[0030] It should be further explained that the explosion-proof junction box 14 is connected to the power module via a wiring board of the electric control system 119 through a cable.

[0031] It should be further explained that the connection and control between the electronic control system 119 and the photometric detector 111, the feed pump 112, the discharge pump 113, the hydrochloric acid pump 114, the starch reagent pump 115, the plunger pump 116, the pure water pump 117, the pure water valve 118 and other components, except for the software, are generally conventional settings in the field. All other various forms of modifications, replacements or changes made to the above structure based on the above content, in accordance with the common technical knowledge and customary means in the field should fall within the scope of protection of the present utility model.

[0032] It should be further explained that the positive pressure protection device 13 includes a pressure reducing valve and a flow meter, and instrument gas is filled into the main cabinet 1 to keep the air pressure in the main cabinet 1 positive, thereby protecting instruments and electrical components and preventing some corrosive gases from entering, avoiding failures during the operation of the analyzer, and extending the service life of the analyzer. In order to protect instruments and electrical components, the positive pressure protection device 13 is always working regardless of whether the analyzer is working or not.

[0033] The photometric detection assembly 1111 includes a photometric detector housing 11111, a photometric detection inner box 11112 assembled at the lower end of the photometric detector housing 11111, the photometric detection inner box 11112 includes a box body 111121, a through-wall wiring terminal 111122 fixed to the lower end of the inner side of the box body 111121 by screws, a photosensitive semiconductor component 111123 and a light-emitting diode 111124 fixedly mounted at the lower end of the inner side of the box body 111121 and arranged opposite to each other, and a light-emitting diode 111124 fixedly mounted below the box body 111121. Inner box bottom plate 111125, motor 111126 placed in the center above inner box bottom plate 111125, pressing plate 111127 placed above motor 111126 and connected to inner box bottom plate 111125 by screws to fix motor 111126, and magnetic stirring seat 111128 fixedly installed on the output end of motor 111126, through-wall wiring terminal 111122 simultaneously connects photosensitive semiconductor component 111123, light-emitting diode 111124 and motor 111126 by wires.

[0034] The analysis cup 1112 includes a cup body 11121 with a large diameter at the upper end and a small diameter at the lower end, a cup cover 11122 assembled on the upper part of the cup body 11121 and provided with a plurality of threaded holes, an O-ring 11123 assembled at the lower end of the cup cover 11122 for improving the sealing performance between the cup body 11121 and the cup cover 11122, a plurality of external threaded straight-through connectors 11124 screwed into the threaded holes of the cup cover 11122, and a flanged connector 11126 for connecting a pipe at the discharge end of a plunger pump, and a magnetic stirrer 11125 placed at the bottom of the cup body 11121. The O-ring 11123 can effectively prevent the detection liquid from overflowing and corroding instruments and meters, and the cup body 11121 is also provided with There is a discharge pipe 111211 close to the bottom of the cup body 11121, a feed pipe 111212 whose length is shorter than the discharge pipe 111211, a hydrochloric acid reagent tube 111213 whose length is shorter than the feed pipe 111212, a starch reagent tube 111214, a pure water tube 111215 and an iodine solution dripping tube 111216 of the same length as the hydrochloric acid reagent tube 111213, the lower ends of the hydrochloric acid reagent tube 111213, the starch reagent tube 111214, the pure water tube 111215 and the iodine solution dripping tube 111216 located in the cup body 11121 all exceed the depth of the part with a larger diameter at the upper end of the cup body 11121 to ensure that the added hydrochloric acid reagent, starch reagent and iodine solution can enter the cup The lower part of the body 11121 is prevented from adhering to the inner wall of the part with a larger diameter at the upper end to affect the detection result. The discharge pipe 111211, the feed pipe 111212, the hydrochloric acid reagent pipe 111213, the starch reagent pipe 111214, and the pure water pipe 111215 are connected and fixed with the corresponding external thread straight-through joints 11124 respectively, and then the feed pipe 111212 is connected to the feed pump 112, the discharge pipe 111211 is connected to the discharge pump 113, the hydrochloric acid reagent pipe 111213 is connected to the hydrochloric acid pump 114, the starch reagent pipe 111214 is connected to the starch reagent pump 115, and the pure water pipe 111215 is connected to the pure Water pump 117, iodine solution dripping tube 111216 is connected and fixed with flanging joint 11126, and then the iodine solution dripping tube 111216 is connected with the pipeline at the discharge end of the plunger pump 116 through the flanging joint 11126, and the pipeline at the discharge end of the plunger pump 116 can also be directly inserted into the cup body 11121 through the flanging joint 11126, and the iodine solution dripping tube 111216 is also a part of the pipeline at the discharge end of the plunger pump 116, which can make the structure simpler. The discharge pipe 111211, the feed pipe 111212, the hydrochloric acid reagent tube 111213, the starch reagent tube 111214, the pure water tube 111215 and the iodine solution dripping tube 111216 are all PFA tubes.

[0035] It should be further explained that the cup cover 11122 is also provided with a cup body drain port, which is one of the external threaded straight-through connectors 11124. The cup body drain port is connected to the outside of the analyzer host through a pipeline to ensure the normal addition of feed, hydrochloric acid, starch and other reagents.

[0036] It should be further explained that, in the comparison of the lengths of the discharge pipe 111211, the feed pipe 111212, the hydrochloric acid reagent pipe 111213, the starch reagent pipe 111214, the pure water pipe 111215 and the iodine solution dripping pipe 111216 recorded in this embodiment, as the discharge pipe 111211 is close to the bottom of the cup body 11121, the feed pipe 111212 is shorter than the discharge pipe 111211, the hydrochloric acid reagent pipe 111213 is shorter than the feed pipe 111212, the starch reagent pipe 111214, the pure water pipe 111215, the iodine solution dripping pipe 111216 and the hydrochloric acid reagent pipe 111 The same length as 213 is just for the convenience of stirring by the magnetic stirrer 11125, easy operation, beautiful product and easy modular production. In fact, as long as the liquid in the cup body 11121 can be drained, the material can be added into the cup body normally, and the added hydrochloric acid, starch, pure water and iodine solution can be fully mixed with the material in the cup body 11121, there is no strict restriction on the lengths of the discharge pipe 111211, the feed pipe 111212, the hydrochloric acid reagent tube 111213, the starch reagent tube 111214, the pure water tube 111215 and the iodine solution drip tube 111216, and they can be set according to actual needs.

[0037] It should be further explained that the distribution and arrangement of the discharge pipe 111211, the feed pipe 111212, the hydrochloric acid reagent tube 111213, the starch reagent tube 111214, the pure water tube 111215 and the iodine solution drip tube 111216 inside the cup body 11121 does not affect the stirring of the materials by the magnetic stirrer 11125 in cooperation with the magnetic stirring seat 111128. At the same time, under the premise of not affecting the stirring effect of the magnetic stirrer 11125, or in order to improve the stirring effect of the magnetic stirrer 11125, the magnetic stirrer 11125 can be designed into a desired shape. In order to prevent the magnetic stirrer 11125 from being corroded by the test liquid, the magnetic stirrer 11125 is generally wrapped with tetrafluoroethylene.

[0038] A circulating sampler inlet 22 connected to a circulating pool in which a sample flows is provided at the lower portion of the circulating sampler 2, a circulating sampler outlet 23 is provided at the upper portion of the circulating sampler 2, a filter membrane tube 21 for filtering impurities and bubbles is provided inside the circulating sampler 2, the lower end of the filter membrane tube 21 is close to the circulating sampler inlet 22, the upper end of the filter membrane tube 21 is away from the circulating sampler inlet 22 and is connected to the input end of the feed pump 112 through a pipeline.

[0039] It should be further explained that the sulfurous acid online analyzer performs normal pressure sampling on the circulation pool through the circulation sampler 2.

[0040] During the working process, the circulating sampler 2, the photometric detector 111 and the feed pump 112 are connected in sequence through pipelines to form a sample feeding system. The input end of the feed pump 112 is connected to the circulating sampler 2, and the output end of the feed pump 112 is connected to the analysis cup 1112 of the photometric detector 111. The sample obtained by the circulating sampler 2 is pumped into the cup body 11121 through the feed pipe 111212.

[0041] During the working process, the photometric detector 111, the feed pump 112 and the discharge pump 113 are connected by pipelines to form a sample replacement system. The input end of the discharge pump 113 is connected to the analysis cup 1112 of the photometric detector 111, and the output end of the discharge pump 113 is extended to the outside of the main cabinet 1 through the pipe system. Specifically, when the sample material is replaced, the feed pump 112 sucks the material and pumps it into the cup body 11121 through the feed pipe 111212. At the same time, the discharge pump 113 sucks it out through the discharge pipe 111211. After a period of time, the discharge pump 113 stops, and the feed pump 112 continues to pump it into the cup body 11121 through the feed pipe 111212 and stops after reaching the set target.

[0042] During operation, the hydrochloric acid pump 114, the starch reagent pump 115, the plunger pump 116 and the photometric detector 111 are connected through pipelines to form a hydrochloric acid supply system, a starch reagent supply system and an iodine solution dripping system, respectively. Specifically, the hydrochloric acid pump 114 sucks in hydrochloric acid and pumps it into the cup body 11121 through the hydrochloric acid reagent tube 111213, and the motor 111126 drives the magnetic stirring seat 111128 to drive the magnetic stirring bar 11125 placed at the bottom of the cup body 11121 to rotate to mix them evenly. After reaching the set target, the starch reagent pump 115 is controlled to suck in the starch reagent and then pump it into the cup body 11121 through the starch reagent tube 111213. 14 is pumped into the cup body 11121 to further mix it evenly. After reaching the set target, the plunger pump 116 draws in the iodine solution and pumps it into the cup body 11121 through the pipeline at the discharge end of the plunger pump 116 through the iodine solution dripping tube 111216 for titration. The photosensitive semiconductor component 111123 of the photometric detector 111 detects that the light signal emitted by the light-emitting diode 111124 and passing through the cup body 11121 reaches the set target value, and the titration is ended. The motor 111126 and the plunger pump 116 are stopped, and the titration is ended. The sulfurous acid content of the test liquid, that is, the material in the analysis cup is calculated by the amount of iodine solution injected.

[0043] During the working process, the photometric detector 111, the feed pump 112, the discharge pump 113 and the pure water pump 117 are connected through pipelines to form a cleaning system. The output end of the pure water pump 117 is connected to the photometric detector 111. Specifically, the pure water pump 117 sucks in pure water and pumps it into the cup body 11121 through the pure water pipe 111215. The motor 111126 drives the magnetic stirring seat 111128 to drive the magnetic stirring bar 11125 to rotate for cleaning. Then the feed pump 112 reverses to clean the pipeline connected to the photometric detector 111, and stops after reaching the set value. The discharge pump 113 sucks out the material and stops after reaching the set value.

[0044] In this embodiment, the starch reagent pump 115 is a peristaltic pump, which can accurately deliver the starch reagent.

[0045] In this embodiment, the photometric titration method is adopted, and the principle and formula for calculating the sulfurous acid content of the material by the amount of iodine solution pumped into the photometric detector 111 by the plunger pump 116 are as follows:

[0046] (1) Principle:

[0047] In an acidic solution, the iodine solution and sulfurous acid produce a redox reaction to generate sulfuric acid and hydrogen iodide. The excess iodine reacts with starch to produce a blue color, which is the end point.

[0048] (2) Calculation formula:

[0049] X(g / 100ml)={(V-Vo)*C*0.032*100}÷V2

[0050] Where:

[0051] X--SO2 content in the sample, g / 100mL;

[0052] C--Concentration of iodine standard solution (I2), moL / L;

[0053] Vo--blank sample volume, mL;

[0054] V--consumption of iodine standard solution, mL;

[0055] V2--the number of milliliters of sample liquid sucked, mL;

[0056] 0.032--The mass of sulfur dioxide in grams equivalent to 1mL, 1moL / L iodine standard solution.

[0057] (3) Allowable error: The absolute value difference between parallel determination results shall not exceed 0.2 g / L, and the arithmetic mean shall be taken as the analysis result.

[0058] The above-mentioned embodiments of the utility model are not intended to limit the protection scope of the utility model, and the implementation methods of the utility model are not limited to these. All other various forms of modifications, replacements or changes made to the above-mentioned structure of the utility model based on the above-mentioned contents of the utility model, in accordance with the common technical knowledge and customary means in the field, without departing from the above-mentioned basic technical ideas of the utility model, should fall within the protection scope of the utility model.

Claims

1. A sulfurous acid online analyzer, comprising a main cabinet, a circulating sampler arranged outside the main cabinet, an analyzer host, a pure water module and a positive pressure protection device installed inside the main cabinet, and an explosion-proof junction box installed outside the main cabinet; characterized in that: A photometric detector is installed at the lower part of the analyzer mainframe, and a feed pump, a discharge pump, a hydrochloric acid pump, a starch reagent pump, a plunger pump, and a pure water pump are connected to the photometric detector through a hose, and a pure water valve is connected to the pure water pump. An electric control system for controlling the photometric detector, the feed pump, the discharge pump, the hydrochloric acid pump, the starch reagent pump, the plunger pump, the pure water pump, and the pure water valve is also installed at the upper part of the analyzer mainframe. The pure water valve is connected to a pure water module. The photometric detector includes a photometric detection component, and an analysis cup inserted into the photometric detection component and specifically connected to the feed pump, the discharge pump, the hydrochloric acid pump, the starch reagent pump, the plunger pump, and the pure water pump.

2. The sulfurous acid online analyzer according to claim 1, characterized in that: The photometric detection component includes a photometric detector shell, a photometric detection inner box assembled at the lower end of the photometric detector shell, the photometric detection inner box includes a box body, a through-wall wiring terminal fixed to the lower end of the inner side of the box body by screws, photosensitive semiconductor components and light-emitting diodes fixedly installed at the lower end of the inner side of the box body and arranged relatively, an inner box bottom plate fixedly installed below the box body, a motor placed in the center above the inner box bottom plate, a pressure plate placed above the motor and connected to the inner box bottom plate by screws to fix the motor, and a magnetic stirring seat fixedly installed on the output end of the motor, and the through-wall wiring terminal is simultaneously connected to the photosensitive semiconductor components, the light-emitting diode and the motor through wires.

3. The sulfurous acid online analyzer according to claim 1, characterized in that: The analysis cup comprises a cup body with a large diameter at the upper end and a small diameter at the lower end, a cup cover mounted on the upper part of the cup body and provided with a plurality of threaded holes, an O-ring mounted at the lower end of the cup cover and used to improve the sealing performance between the cup body and the cup cover, a plurality of external threaded straight-through joints screwed into the threaded holes of the cup cover and a flanged joint for connecting a pipeline at the discharge end of a plunger pump, a magnetic stirrer placed at the bottom of the cup body, a discharge pipe close to the bottom of the cup body, a feed pipe shorter than the discharge pipe, a hydrochloric acid reagent tube shorter than the feed pipe, a starch reagent tube of the same length as the hydrochloric acid reagent tube, a pure water tube and an iodine solution dripping tube, and a hydrochloric acid reagent tube. , starch reagent tube, pure water tube and iodine solution dripping tube are located in the cup body, and the lower ends all exceed the depth of the part with larger diameter at the upper end of the cup body; the discharge tube, feed tube, hydrochloric acid reagent tube, starch reagent tube and pure water tube are connected and fixed with corresponding external thread straight joints respectively; and then the feed tube is connected to the feed pump, the discharge tube is connected to the discharge pump, the hydrochloric acid reagent tube is connected to the hydrochloric acid pump, the starch reagent tube is connected to the starch reagent pump, and the pure water tube is connected to the pure water pump respectively through the external thread straight joint; the iodine solution dripping tube is connected and fixed with the flanging joint, and then the iodine solution dripping tube is connected to the pipeline at the discharge end of the plunger pump through the flanging joint.

4. The sulfurous acid online analyzer according to claim 3, characterized in that: The cup cover is also provided with a cup body drain port, which is one of the external thread straight-through connectors, and the cup body drain port is connected to the outside of the analyzer host through a pipeline.

5. The sulfurous acid online analyzer according to claim 1, characterized in that: The circulating sampler, the photometric detector and the feed pump are connected in sequence through pipelines to form a sample feeding system. The input end of the feed pump is connected to the circulating sampler, and the output end of the feed pump is connected to the analysis cup of the photometric detector.

6. The sulfurous acid online analyzer according to claim 1, characterized in that: The photometric detector, the feed pump and the discharge pump are connected through pipelines to form a sample replacement system. The input end of the discharge pump is connected to the analysis cup of the photometric detector, and the output end of the discharge pump is extended to the outside of the main cabinet through a pipe system.

7. The sulfurous acid online analyzer according to claim 1, characterized in that: The hydrochloric acid pump, starch reagent pump, plunger pump and photometric detector are connected through pipelines to form a hydrochloric acid supply system, a starch reagent supply system and an iodine solution dropping system respectively.

8. The sulfurous acid online analyzer according to claim 1, characterized in that: The photometric detector, the feed pump, the discharge pump and the pure water pump are connected through pipelines to form a cleaning system, and the output end of the pure water pump is connected to the photometric detector.

9. The sulfurous acid online analyzer according to claim 1, characterized in that: The starch reagent pump is a peristaltic pump.

10. The sulfurous acid online analyzer according to claim 1, characterized in that: The positive pressure protection device includes a pressure reducing valve and a flow meter; The electric control system includes a touch screen, a power module, a wiring board, a main control board, and a PLC controller. The touch screen is arranged on the front panel of the analyzer host. The power module, the wiring board, the main control board, and the PLC controller are arranged behind the touch screen. A power switch and a USB interface are arranged on the front panel of the analyzer host beside the touch screen. The explosion-proof junction box is connected to the power module through the wiring board of the electric control system via a cable; The lower part of the circulating sampler is provided with a circulating sampler inlet connected to a circulation pool in which a sample circulates, the upper part of the circulating sampler is provided with a circulating sampler outlet, and the circulating sampler is provided with a filter membrane tube for filtering impurities and bubbles, the lower end of the filter membrane tube is close to the circulating sampler inlet, and the upper end of the filter membrane tube is far away from the circulating sampler inlet and is connected to the input end of the feed pump through a pipeline.

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