Constant temperature drying oven for determining chlorate content and determination method using the drying oven

Abstract

The invention discloses a constant temperature drying oven for determining chlorate content and a determination method using the drying oven, and relates to the technical field of constant temperature drying ovens. The invention comprises a placing plate and a partition plate of a main body of the constant temperature drying oven, wherein a placing plate is movably installed inside the main body of the constant temperature drying oven, and a plurality of groups of partition plates are installed on the upper end of the placing plate, and mounting columns are movably installed inside the main body of the constant temperature drying oven, and the placing plate and the plurality of groups of partition plates are fixedly connected to the mounting columns, and a heating module is installed inside the plurality of groups of partition plates, and a plurality of groups of reserved holes are provided on the upper end of the placing plate. The invention provides a placing plate and a partition plate, and the plurality of groups of partition plates divide the upper end of the placing plate into a plurality of placing spaces, and the heating modules inside the partition plates heat the placing spaces respectively, so that when taking a group of experimental reagents, the other plurality of groups of experimental reagents maintain a dry constant temperature effect, thereby improving the accuracy of experimental data and the experimental effect.

Description

Technical Field

[0001] The invention relates to the technical field of constant temperature drying ovens, in particular to a constant temperature drying oven for measuring chlorate content and a measuring method using the drying oven. Background Art

[0002] Sodium hypochlorite is an inorganic chlorine-containing disinfectant. Solid sodium hypochlorite is a white powder. General industrial products are colorless or light yellow liquids with a pungent odor. It is easily soluble in water to generate caustic soda and hypochlorous acid. Sodium hypochlorite is used as a bleaching agent in pulp, textiles and chemical fibers. It is used as a water purifier, bactericide, disinfectant, etc. in water treatment. Industrial sodium hypochlorite contains sodium hypochlorite, sodium hydroxide, chlorine, sodium chlorate, etc. Hydrogen peroxide can reduce hypochlorite and chlorine, but cannot reduce chlorate. In order to obtain the content of chlorate in sodium hypochlorite, an experiment is conducted. In a strong acid medium, under heating conditions, a certain amount of ammonium ferrous sulfate is used to reduce chlorate. The excess ammonium ferrous sulfate is back-titrated with sodium diphenylamine sulfonate as an indicator using a standard potassium dichromate solution. The chlorate content in sodium hypochlorite is calculated based on the amount of potassium dichromate used. During the experiment, a constant temperature drying oven is an indispensable experimental instrument.

[0003] In many scientific experiments, samples need to be dried at a constant temperature in order to study their physical, chemical or biological properties. For example, in material science research, by drying material samples in a constant temperature drying oven, their stable physical properties can be obtained. In biological research, a constant temperature drying oven can be used to dry cell cultures at a constant temperature to study their response to changes in temperature and humidity.

[0004] In the prior art, when a constant temperature drying oven is used to process multiple experimental reagents, the drying time needs to be kept consistent. When one of the experimental reagents is taken out, the remaining experimental reagents being dried will be affected by the temperature, and it is difficult to maintain the constant temperature effect of the remaining experimental reagents. In addition, when the constant temperature drying oven is processing liquid samples, gas will be generated, and the gas will flow into the conical flasks where other liquid samples are placed, thereby affecting the experimental data. Summary of the invention

[0005] Based on this, the purpose of the present invention is to provide a constant temperature drying oven for determining chlorate content and a determination method using the drying oven, so as to solve the technical problems in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions: a constant temperature drying oven for determining chlorate content and a determination method using the drying oven, comprising a constant temperature drying oven main body placement plate and a partition plate, wherein a placement plate is movably installed inside the constant temperature drying oven main body, and a plurality of partition plates are installed on the upper end of the placement plate;

[0007] The main body of the constant temperature drying oven is movably installed with a mounting column, and the placement plate and multiple groups of partitions are fixedly connected to the mounting column, and multiple groups of partitions are installed with heating modules inside, and the upper end of the placement plate is provided with multiple groups of reserved holes, and one side of the main body of the constant temperature drying oven is provided with a box opening, and the outer wall of the main body of the constant temperature drying oven is movably installed with a box door;

[0008] A driving motor is installed inside the main body of the constant temperature drying box, a driving shaft is installed at the output end of the driving motor, and the driving shaft is movably connected to the placement plate, and a fan is sleeved on the outer wall of the driving shaft.

[0009] By adopting the above technical solution, the problem of keeping other groups of experimental reagents dry and at a constant temperature when taking one group of experimental reagents is solved. Multiple groups of partitions divide the upper end of the placement plate into multiple independent placement spaces, and the heating modules inside the partitions heat the multiple placement spaces respectively. Therefore, when taking one group of experimental reagents, other groups of experimental reagents can maintain a dry and constant temperature effect, thereby improving the accuracy of experimental data and improving experimental results.

[0010] The present invention is further configured such that slideways are symmetrically installed on the outer wall of the main body of the constant temperature drying box, slide bars are installed on both upper and lower ends of the box door, and two groups of slide bars are movably connected to the inner walls of the two groups of slideways respectively, and a toothed plate is installed on the outer wall of one group of the slide bars.

[0011] By adopting the above technical solution, when the box door moves, the two groups of slide bars are driven to move in the two groups of slideways respectively, thereby driving the tooth plate to move.

[0012] The present invention is further configured such that a plurality of groups of shrinking cylinders are movably installed in the main body wall of the constant temperature drying box, and sprockets are sleeved on the outer walls of the plurality of groups of shrinking cylinders, chains matching with the sprockets are arranged between the plurality of groups of shrinking cylinders, a limiting gear is installed on the upper end of one group of shrinking cylinders, and the limiting gear is meshingly connected with the tooth plate.

[0013] By adopting the above technical solution, when the tooth plate moves, the limit gear is displaced because the tooth plate is meshed with the limit gear, thereby driving a group of shrinking cylinders to rotate, and multiple groups of shrinking cylinders are connected through chains and sprockets, so multiple groups of shrinking cylinders rotate synchronously.

[0014] The present invention is further configured such that a plurality of groups of the shrinking tubes are movably provided with a linkage shaft, and the inner wall of the shrinking tube is threadedly connected to the outer wall of the linkage shaft, a second linkage gear is installed at the bottom end of the plurality of groups of the linkage shafts, and a first linkage gear is sleeved on the outer wall of the plurality of groups of the linkage shafts.

[0015] By adopting the above technical solution, multiple groups of shrinking cylinders rotate synchronously, thereby driving one end of multiple groups of linkage shafts to move downward, and further driving the first linkage gear and the second linkage gear to move.

[0016] The present invention is further configured such that a plurality of transmission shafts are movably installed in the main body wall of the constant temperature drying box, and the plurality of transmission shafts are respectively connected to the driving shafts through synchronous belts, and transmission gears are installed at the bottom ends of the plurality of transmission shafts, and the plurality of transmission gears are respectively meshed and connected with a plurality of second linkage gears.

[0017] By adopting the above technical solution, the driving shaft rotates, and multiple sets of transmission shafts are respectively connected to the driving shaft through synchronous belts, thereby driving the multiple sets of transmission shafts to rotate, and then driving the multiple sets of transmission gears to rotate. Because the multiple sets of transmission gears are respectively meshed and connected with the multiple sets of second connecting gears, the multiple sets of second connecting gears rotate, thereby driving the multiple sets of connecting shafts to rotate.

[0018] The present invention is further configured such that a gear ring is sleeved on the outer wall of the placement plate, and the gear ring is respectively meshed and connected with a plurality of groups of first linkage gears.

[0019] By adopting the above technical solution, multiple groups of second linkage gears rotate, thereby driving multiple groups of linkage shafts to rotate, and then driving multiple groups of first linkage gears to rotate. Since multiple groups of first linkage gears are respectively engaged with the gear rings, the gear rings rotate, thereby driving the placement plate to rotate, and the placement space corresponding to the box opening is replaced.

[0020] The present invention is further configured such that a reserved groove is provided on the outer wall of the main body of the constant temperature drying box, an elastic sheet is installed inside the reserved groove, a limiting block is installed at one end of the elastic sheet, a limiting groove is provided on the inner wall of the box door, and the limiting groove is movably connected to one end of the limiting block.

[0021] By adopting the above technical solution, when the closed door moves, one end of the door squeezes one end of the limit block, and the limit block is displaced and moves into the reserved groove. When the limit groove corresponds to the reserved groove, the elastic sheet pushes the limit block, so that one end of the limit block enters the inside of the limit groove, thereby fixing the door.

[0022] The present invention is further configured such that a handle is movably mounted on the outer wall of the door, and one end of the handle is movably connected to the inner wall of the limiting groove.

[0023] By adopting the above technical solution, before opening the box door, the experimenter squeezes the handle to push the limit block in the limit groove, releases the fixation of the box door, and then pushes the box door to move.

[0024] The present invention is further configured such that an exhaust port is provided on one side of the main body of the constant temperature drying oven, and the exhaust port is externally connected to an air inlet end of a toxic gas treatment device.

[0025] By adopting the above technical solution, the drive shaft rotates, thereby driving the fan to rotate, thereby generating negative pressure, so that the toxic gas flows through the reserved hole to the lower end of the placement plate, and flows through the exhaust port to the inside of the toxic gas treatment device for treatment.

[0026] The present invention is further configured such that a gas pipe is installed in the upper end wall of the constant temperature drying oven body, one end of the gas pipe is provided with an air inlet extending to the outer wall of the constant temperature drying oven body, and the air inlet is externally connected to the air outlet of the toxic gas treatment device, and the gas pipe is provided with multiple groups of air outlets extending to the inner wall of the constant temperature drying oven body.

[0027] By adopting the above technical solution, after the toxic gas treatment device treats the toxic gas, the gas enters the gas pipeline through the air inlet and enters the main body of the constant temperature drying oven through the air outlet, thereby ensuring the gas content inside the constant temperature drying oven.

[0028] The method for determining the chlorate content using the above drying oven comprises the following steps:

[0029] S1: Accurately transfer 5.00 mL of the sample into a 250 mL conical flask containing 20 mL of pure water. First, add hydrogen peroxide in small amounts and multiple times until no bubbles are generated, and add 0.5 mL in excess. Then add 0.5 mL of sulfuric acid, and then add 2 mL of saturated sodium carbonate solution, 20 mL of pure water and several clean glass beads or zeolites. Gently shake the conical flask to mix the solution, and place it in a constant temperature drying oven to heat and boil for 10 minutes.

[0030] S2: After cooling to room temperature in a constant temperature drying oven, add 20 mL of sulfuric acid solution and 25 mL of ammonium ferrous sulfate standard solution, and heat and boil for 1 min.

[0031] S3: After cooling again, add 10 mL of phosphoric acid solution and 6 to 8 drops of sodium diphenylamine sulfonate indicator solution, and titrate with potassium dichromate standard solution. The end point is when the color of the solution changes from colorless to green to purple-blue, and record the amount of potassium dichromate standard titration solution V1.

[0032] S4: While measuring the sample, use 5.00mL of pure water to perform a blank test according to the same operating steps, and record the amount of potassium dichromate standard titration solution V2.

[0033] In summary, the present invention mainly has the following beneficial effects:

[0034] 1. The present invention solves the problem of keeping multiple groups of experimental reagents dry and at a constant temperature when taking one group of experimental reagents by providing a placement plate and a partition. Multiple groups of partitions divide the upper end of the placement plate into multiple independent placement spaces, and the multiple placement spaces are heated respectively by the heating module inside the partition. Therefore, when taking one group of experimental reagents, the other multiple groups of experimental reagents are kept dry and at a constant temperature, thereby improving the accuracy of experimental data and improving experimental effects.

[0035] 2. The present invention solves the problem of gas flow by providing a placement plate, reserved holes, partitions and fans. When liquid samples are processed, harmful gases will be generated, and the partitions prevent the gas from flowing into the conical flasks where other liquid samples are placed, further improving the accuracy of experimental data. The fan rotates to generate negative pressure, which guides the gas so that the gas flows out of the placement space through the reserved holes, avoiding the accumulation of harmful gases in the placement space. When the experimenters take out the experimental samples, the experimenters are protected, thereby improving their safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a main schematic diagram of the constant temperature drying oven for measuring chlorate content according to the present invention;

[0037] Figure 2 It is a schematic diagram of the exhaust port of the constant temperature drying box for measuring the chlorate content of the present invention;

[0038] Figure 3 It is a schematic diagram of the box opening of the constant temperature drying box for measuring the chlorate content of the present invention;

[0039] Figure 4 It is a schematic diagram of the internal structure of the constant temperature drying oven main body of the constant temperature drying oven for chlorate content determination of the present invention;

[0040] Figure 5 This is a schematic diagram of the box door of the constant temperature drying box for chlorate content determination according to the present invention;

[0041] Figure 6 It is a schematic diagram of a limit block of a constant temperature drying oven for measuring chlorate content according to the present invention;

[0042] Figure 7 It is a schematic diagram of a placement plate of a constant temperature drying oven for chlorate content determination according to the present invention;

[0043] Figure 8 It is a schematic diagram of a driving motor of a constant temperature drying oven for measuring chlorate content according to the present invention;

[0044] Fig. 9 It is a schematic diagram of the transmission shaft of the constant temperature drying oven for measuring chlorate content of the present invention;

[0045] Fig.10 It is a schematic diagram of the shrinkage tube of the constant temperature drying oven for chlorate content determination according to the present invention;

[0046] Fig.11 The diagram is a schematic diagram of connecting multiple groups of shrinkage tubes in a constant temperature drying oven for determining chlorate content according to the present invention.

[0047] In the figure: 1. Constant temperature drying box body; 2. Slide; 3. Box mouth; 4. Limit block; 5. Elastic sheet; 6. Exhaust port; 7. Air inlet; 8. Box door; 9. Handle; 10. Slide bar; 11. Limit groove; 12. Reserved groove; 13. Tooth plate; 14. Placement plate; 15. Reserved hole; 16. Mounting column; 17. Partition plate; 18. Gear ring; 19. Driving motor; 20. Driving shaft; 21. Fan; 22. Transmission shaft; 23. Transmission gear; 24. Shrinking cylinder; 25. Limit gear; 26. Linking shaft; 27. First linkage gear; 28. Second linkage gear; 29. ​​Chain; 30. Air pipe; 31. Air outlet. DETAILED DESCRIPTION

[0048] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0049] The following describes an embodiment of the present invention based on its overall structure.

[0050] The chlorate content is determined using a constant temperature drying oven, such as Figure 1 - Fig.11 As shown, it includes a constant temperature drying oven body 1, a placement plate 14 and a partition 17. The placement plate 14 is movably installed inside the constant temperature drying oven body 1, and multiple groups of partitions 17 are installed on the upper end of the placement plate 14;

[0051] A mounting column 16 is movably installed inside the main body 1 of the constant temperature drying oven, and the placement plate 14 and multiple groups of partitions 17 are fixedly connected to the mounting column 16. The multiple groups of partitions divide the upper end of the placement plate into multiple placement spaces. A heating module is installed inside the multiple groups of partitions 17. The heating modules inside the partitions heat the placement spaces respectively. Multiple groups of reserved holes 15 are provided at the upper end of the placement plate 14. A box opening 3 is provided on one side of the main body 1 of the constant temperature drying oven. A box door 8 is movably installed on the outer wall of the main body 1 of the constant temperature drying oven.

[0052] A driving motor 19 is installed inside the constant temperature drying box body 1, and a driving shaft 20 is installed at the output end of the driving motor 19. The driving shaft 20 is movably connected to the placement plate 14, and a fan 21 is sleeved on the outer wall of the driving shaft 20. The driving shaft 20 drives the placement plate 14 and the fan 21 to rotate.

[0053] See also Figure 1 - Figure 5 The outer wall of the main body 1 of the constant temperature drying box is symmetrically installed with slideways 2, and the upper and lower ends of the box door 8 are installed with slide bars 10, and the two groups of slide bars 10 are movably connected to the inner walls of the two groups of slideways 2 respectively. A tooth plate 13 is installed on the outer wall of one group of slide bars 10. When the box door 8 moves, the two groups of slide bars 10 are driven to move in the two groups of slideways 2 respectively, thereby driving the tooth plate 13 to move.

[0054] See also Figure 4 - Fig.11 A plurality of shrinking cylinders 24 are movably installed in the wall of the main body 1 of the constant temperature drying box, and a sprocket is sleeved on the outer wall of the plurality of shrinking cylinders 24, and a chain 29 matched with the sprocket is arranged between the plurality of shrinking cylinders 24, and a limit gear 25 is installed on the upper end of a group of shrinking cylinders 24, and the limit gear 25 is meshed and connected with the tooth plate 13. When the tooth plate 13 moves, the limit gear 25 is displaced because the tooth plate 13 is meshed and connected with the limit gear 25, thereby driving a group of shrinking cylinders 24 to rotate, and the plurality of shrinking cylinders 24 are connected with the sprocket through the chain 29, so the plurality of shrinking cylinders 24 rotate synchronously.

[0055] See also Figure 4 - Fig.11 A linkage shaft 26 is movably installed inside the multiple sets of shrinking cylinders 24, and the inner wall of the shrinking cylinder 24 is threadedly connected to the outer wall of the linkage shaft 26. A second linkage gear 28 is installed at the bottom end of the multiple sets of linkage shafts 26, and a first linkage gear 27 is sleeved on the outer wall of the multiple sets of linkage shafts 26. The multiple sets of shrinking cylinders 24 rotate synchronously, thereby driving one end of the multiple sets of linkage shafts 26 to move downward, and then driving the first linkage gear 27 and the second linkage gear 28 to move.

[0056] See also Figure 4 - Fig.11 A plurality of transmission shafts 22 are movably installed in the wall of the main body 1 of the constant temperature drying box, and the plurality of transmission shafts 22 are respectively connected to the drive shaft 20 through synchronous belts. Transmission gears 23 are installed at the bottom ends of the plurality of transmission shafts 22, and the plurality of transmission gears 23 are respectively meshed and connected with the plurality of second linkage gears 28. When the drive shaft 20 rotates, the plurality of transmission shafts 22 are respectively connected to the drive shaft 20 through synchronous belts, thereby driving the plurality of transmission shafts 22 to rotate, and then driving the plurality of transmission gears 23 to rotate. Since the plurality of transmission gears 23 are respectively meshed and connected with the plurality of second linkage gears 28, the plurality of second linkage gears 28 rotate, thereby driving the plurality of linkage shafts 26 to rotate.

[0057] See also Figure 4 - Fig.11A gear ring 18 is sleeved on the outer wall of the placement plate 14, and the gear ring 18 is respectively meshed and connected with multiple groups of first linkage gears 27. Multiple groups of second linkage gears 28 rotate, thereby driving multiple groups of linkage shafts 26 to rotate, and then driving multiple groups of first linkage gears 27 to rotate. Because multiple groups of first linkage gears 27 are respectively meshed and connected with the gear ring 18, the gear ring 18 rotates, thereby driving the placement plate 14 to rotate, and the placement space corresponding to the box opening 3 is replaced.

[0058] See also Figure 3 - Figure 6 A reserved groove 12 is provided on the outer wall of the main body 1 of the constant temperature drying oven, and an elastic sheet 5 is installed inside the reserved groove 12. A limit block 4 is installed at one end of the elastic sheet 5. A limit groove 11 is provided on the inner wall of the door 8, and the limit groove 11 is movably connected with one end of the limit block 4. When the door 8 is closed and moved, one end of the door 8 squeezes one end of the limit block 4, and the limit block 4 is displaced and moves into the reserved groove 12. When the limit groove 11 corresponds to the reserved groove 12, the elastic sheet 5 pushes the limit block 4 so that one end of the limit block 4 enters the limit groove 11, so that the door 8 is fixed.

[0059] See also Figure 1 - Figure 5 A handle 9 is movably installed on the outer wall of the box door 8, and one end of the handle 9 is movably connected to the inner wall of the limiting groove 11. Before opening the box door 8, the experimenter squeezes the handle 9 to push the limiting block 4 in the limiting groove 11, releases the fixation of the box door 8, and then pushes the box door 8 to move.

[0060] See also Figure 2 - Figure 4 An exhaust port 6 is provided on one side of the main body 1 of the constant temperature drying oven, and the exhaust port 6 is externally connected to the air inlet end of the toxic gas treatment device. The driving shaft 20 rotates, thereby driving the fan 21 to rotate, thereby generating negative pressure, so that the toxic gas flows through the reserved hole 15 to the lower end of the placement plate 14, and flows through the exhaust port 6 to the inside of the toxic gas treatment device for treatment.

[0061] See also Figure 2 - Figure 4 A gas pipe 30 is installed in the upper end wall of the constant temperature drying oven main body 1. An air inlet 7 is provided at one end of the gas pipe 30 and extends to the outer wall of the constant temperature drying oven main body 1. The air inlet 7 is externally connected to the gas outlet end of the toxic gas treatment device. The gas pipe 30 is provided with multiple groups of gas outlets 31 extending to the inner wall of the constant temperature drying oven main body 1. After the toxic gas treatment device treats the toxic gas, the gas enters the gas pipe 30 through the air inlet 7 and enters the constant temperature drying oven main body 1 through the air outlet 31, thereby ensuring the gas content inside the constant temperature drying oven main body 1.

[0062] The working principle of the present invention is as follows: when the experimenter uses the constant temperature drying box to perform the chlorate content determination experiment, the experimenter first opens the box door 8 to expose the box opening 3, and then places the conical bottle containing the experimental sample on the upper end of the placement plate 14;

[0063] When the box door 8 moves, the two groups of slide bars 10 are driven to move in the two groups of slideways 2 respectively, thereby driving the tooth plate 13 to move, and the tooth plate 13 is meshed and connected with the limit gear 25, so the limit gear 25 is moved, thereby driving a group of shrinking cylinders 24 to rotate, and multiple groups of shrinking cylinders 24 are connected with the sprocket through the chain 29, so the multiple groups of shrinking cylinders 24 rotate synchronously, thereby driving one end of multiple groups of linkage shafts 26 to move downward, and then driving the first linkage gear 27 and the second linkage gear 28 to move, so that the first linkage gear 27 and the second linkage gear 28 are moved to the side of the gear ring 18 and the transmission gear 23 respectively;

[0064] The experimenter starts the driving motor 19, and the driving shaft 20 at the output end of the driving motor 19 rotates, and the multiple sets of transmission shafts 22 are respectively connected to the driving shafts 20 through synchronous belts, thereby driving the multiple sets of transmission shafts 22 to rotate, and then driving the multiple sets of transmission gears 23 to rotate. Since the multiple sets of transmission gears 23 are respectively meshed and connected with the multiple sets of second linkage gears 28, the multiple sets of second linkage gears 28 rotate, thereby driving the multiple sets of linkage shafts 26 to rotate, and then driving the multiple sets of first linkage gears 27 to rotate. Since the multiple sets of first linkage gears 27 are respectively meshed and connected with the gear ring 18, the gear ring 18 rotates, thereby driving the placement plate 14 to rotate, and the placement space corresponding to the box opening 3 is replaced, so that the remaining conical bottles are placed in different placement spaces respectively;

[0065] After the multiple groups of conical bottles are placed, the experimenter turns off the driving motor 19 and pulls the box door 8 through the handle 9 to close the box door 8. When the box door moves, it drives the multiple groups of shrinking cylinders 24 to move, thereby driving the multiple groups of transmission shafts 22 to move, and then drives the first linkage gear 27 and the second linkage gear 28 to separate from the gear ring 18 and the transmission gear 23 respectively;

[0066] When the box door 8 moves, one end of the box door 8 squeezes one end of the limit block 4, and the limit block 4 is displaced and moves into the reserved groove 12. When the limit groove 11 corresponds to the reserved groove 12, the elastic sheet 5 pushes the limit block 4, so that one end of the limit block 4 enters the limit groove 11, so that the box door 8 is fixed;

[0067] When the box door 8 is closed, the experimenter starts the heating module in the partition 17 to heat the experimental sample in the conical flask. The sample generates toxic gas after heating. The experimenter starts the driving motor 19 to drive the driving shaft 20 to rotate, thereby driving the fan 21 to rotate, thereby generating negative pressure, so that the toxic gas flows through the reserved hole 15 to the lower end of the placement plate 14, and flows through the exhaust port 6 to the inside of the toxic gas treatment device for treatment;

[0068] When the experimenter needs to take out the processed experimental samples, first turn off the drive motor 19, then squeeze the handle 9 to push the limit block 4 in the limit groove 11, release the fixation of the box door 8, and take out the conical bottles one by one according to the above steps;

[0069] The present invention arranges the placement plate 14 and the partition 17 so that when one group of experimental reagents is taken, the other groups of experimental reagents can maintain a dry constant temperature effect, thereby improving the accuracy of experimental data and improving the experimental effect.

[0070] The method for determining the chlorate content using the above-mentioned constant temperature drying oven is specifically to determine the chlorate content in sodium hypochlorite. Specifically, the potassium dichromate titration method can be used for determination.

[0071] Industrial sodium hypochlorite contains sodium hypochlorite, sodium hydroxide, chlorine, sodium chlorate, etc. Hydrogen peroxide can reduce hypochlorite and chlorine, but cannot reduce chlorate.

[0072] In a strong acid medium, under heating conditions, a certain amount of ammonium ferrous sulfate is used to reduce chlorate, and the excess ammonium ferrous sulfate is back-titrated with a potassium dichromate standard solution using sodium diphenylamine sulfonate as an indicator. The chlorate content in sodium hypochlorite is calculated based on the amount of potassium dichromate used.

[0073] Record of potassium dichromate titration method: Li Jing. Determination of sodium chlorate content in industrial sodium hypochlorite solution [J]. Chlor-alkali Industry, 2014 (12): 38-39

[0074] GB / T 5750.10-2006 "Standard test methods for drinking water - Indicators for disinfection by-products" 13.2.8.2 Determination of sodium chlorate content in sodium chlorite.

[0075] Industrial sodium hypochlorite contains ClO- and Cl2, which can be removed by adding hydrogen peroxide.

[0076] Insufficient addition of hydrogen peroxide will result in incomplete reduction of ClO- and Cl2. If too much is added, the excess hydrogen peroxide will be reduced by ammonium ferrous sulfate. Both situations will affect the test results. Therefore, a small amount of hydrogen peroxide can be removed by heating and decomposition under the promotion of sodium carbonate.

[0077] Ammonium ferrous sulfate is oxidized by chlorate into yellow ammonium ferric sulfate, which affects the judgment of the titration color. Phosphate-complexed iron ions can be added to eliminate the interference.

[0078] The above determination method can be applied to the determination of chlorate content in industrial sodium hypochlorite solution. The instruments and equipment required for the above determination method are: 1000-2000 W controllable electric furnace; titrator: 50 mL; conical flask: 250 mL; pipette: 5ml, 10 mL; volumetric flask: 1 000 mL; measuring cylinder 50 mL; analytical balance: sensitivity 0.0001g; dropper.

[0079] The above-mentioned determination method also requires the use of the above-mentioned constant temperature drying oven.

[0080] Materials and reagents involved in the above determination method: sulfuric acid (H2SO4), ρ=1.84 g / mL, high purity; ammonium ferrous sulfate ([(NH4)2Fe(SO4)2·6H2O]); hydrogen peroxide solution (wt=3%): weigh 20g of 30% hydrogen peroxide solution, dilute it to 200g with water to obtain 3% hydrogen peroxide solution; saturated sodium carbonate solution: weigh 49.7g sodium carbonate, dissolve it in 100ml pure water, cover it, boil it and let it cool; phosphoric acid solution, 1+1. (The volume ratio of analytical grade phosphoric acid to water is 1:1); Potassium dichromate (K2Cr2O7) standard reagent, take an appropriate amount of potassium dichromate and dry it in a 120℃ oven to constant weight; Potassium dichromate standard solution c (1 / 6K2Cr2O7) = 0.1 mol / L: Accurately weigh 4.903g potassium dichromate (3.6), dissolve it in water, make up to 1000mL, and shake well; Sodium diphenylamine sulfonate indicator solution (5 g / L): weigh 0.5g sodium diphenylamine sulfonate, dissolve it in water, and dilute it to 100mL with water; Sulfuric acid solution c (H2SO4) = 3 mol / L: Measure 163mL concentrated sulfuric acid and dilute it to 1L with pure water; Ammonium ferrous sulfate standard solution c (FeSO4) = 0.1 mol / L: Weigh 39.2g ammonium ferrous sulfate (3.2) and dissolve it in water, add 20ml sulfuric acid (3.1), and dilute to 1000ml after the solution cools.

[0081] The sample should be placed in a clean, dry brown bottle with a ground stopper and sealed. The sample volume should not be less than 200 mL and should be stored in a cool, ventilated place. Keep away from fire and heat sources.

[0082] The chlorate content determination method comprises the following steps:

[0083] S1: Accurately transfer 5.00 mL of the sample into a 250 mL conical flask containing 20 mL of pure water. First, add hydrogen peroxide in small amounts and multiple times until no bubbles are generated, and add 0.5 mL in excess. Then add 0.5 mL of sulfuric acid, and then add 2 mL of saturated sodium carbonate solution, 20 mL of pure water and several clean glass beads or zeolites. Gently shake the conical flask to mix the solution, and place it in a constant temperature drying oven to heat and boil for 10 minutes.

[0084] S2: After cooling to room temperature in a constant temperature drying oven, add 20 mL of sulfuric acid solution and 25 mL of ammonium ferrous sulfate standard solution, and heat and boil for 1 min.

[0085] S3: After cooling again, add 10 mL of phosphoric acid solution and 6 to 8 drops of sodium diphenylamine sulfonate indicator solution, and titrate with potassium dichromate standard solution. The end point is when the color of the solution changes from colorless to green to purple-blue, and record the amount of potassium dichromate standard titration solution V1.

[0086] S4: While measuring the sample, use 5.00mL of pure water to perform a blank test according to the same operating steps, and record the amount of potassium dichromate standard titration solution V2.

[0087] The calculation formula of chlorate content is:

[0088] (1)

[0089] Where: ρ——mass concentration of chlorate, in mg / L;

[0090] V2——The volume of potassium dichromate standard titration solution consumed in the blank test, in milliliters (mL);

[0091] V1——The volume of potassium dichromate standard titration solution consumed when titrating the sample, in milliliters (mL);

[0092] V——the volume of the sample measured, in milliliters (mL);

[0093] c(1 / 6K2Cr2O7)——equivalent concentration of potassium dichromate standard titration solution, in moles per liter (mol / L);

[0094] 13.908 – The molar mass of chlorate equivalent to 1L of potassium dichromate [c(1 / 6K2Cr2O7)=1mol / L], in g / mol.

[0095] The standard solution with chlorate content of 1000 mg / L was measured 7 times, with a relative standard deviation of 2.7% and a relative error of 2.6%.

[0096] The applicability of this method to actual samples was tested. The statistical results of the determination of 6 samples showed that when the chlorate content was about 700 mg / L, the relative standard deviation was 2.9%.

[0097] Although an embodiment of the present invention has been shown and described, this specific embodiment is merely an explanation of the present invention and is not a limitation of the invention. The specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions and variations to the embodiments without creative contributions as needed without departing from the principles and purpose of the present invention. However, as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A constant temperature drying oven for chlorate content determination experiment, comprising a constant temperature drying oven body (1), a placement plate (14) and a partition (17), characterized in that: A placement plate (14) is movably installed inside the constant temperature drying oven body (1), and a plurality of partition plates (17) are installed on the upper end of the placement plate (14); The constant temperature drying oven body (1) has a mounting column (16) movably mounted therein, and the placement plate (14) and a plurality of groups of partitions (17) are fixedly connected to the mounting column (16), a heating module is mounted therein, a plurality of groups of reserved holes (15) are provided at the upper end of the placement plate (14), a box opening (3) is provided at one side of the constant temperature drying oven body (1), and a box door (8) is movably mounted on the outer wall of the constant temperature drying oven body (1); A driving motor (19) is installed inside the constant temperature drying oven body (1), a driving shaft (20) is installed at the output end of the driving motor (19), and the driving shaft (20) is movably connected to the placement plate (14), and a fan (21) is sleeved on the outer wall of the driving shaft (20); The outer wall of the constant temperature drying oven body (1) is symmetrically provided with slideways (2), the upper and lower ends of the oven door (8) are provided with slide bars (10), and the two sets of slide bars (10) are movably connected to the inner walls of the two sets of slide bars (2) respectively, and the outer wall of one set of the slide bars (10) is provided with a tooth plate (13); A plurality of shrinking cylinders (24) are movably mounted in the wall of the constant temperature drying box body (1), and sprockets are sleeved on the outer walls of the plurality of shrinking cylinders (24). Chains (29) matching the sprockets are arranged between the plurality of shrinking cylinders (24). A limit gear (25) is mounted on the upper end of one group of shrinking cylinders (24), and the limit gear (25) is meshedly connected with the toothed plate (13); A linkage shaft (26) is movably mounted inside each of the plurality of shrinking tubes (24), and the inner wall of the shrinking tube (24) and the outer wall of the linkage shaft (26) are threadedly connected. A second linkage gear (28) is mounted at the bottom end of each of the plurality of linkage shafts (26), and a first linkage gear (27) is sleeved on the outer wall of each of the plurality of linkage shafts (26); A plurality of transmission shafts (22) are movably mounted in the wall of the constant temperature drying oven body (1), and the plurality of transmission shafts (22) are respectively connected to the drive shafts (20) via synchronous belts, and transmission gears (23) are mounted at the bottom ends of the plurality of transmission shafts (22), and the plurality of transmission gears (23) are respectively meshed and connected to the plurality of second linkage gears (28); An air delivery pipe (30) is installed in the upper wall of the constant temperature drying oven body (1); an air inlet (7) is provided at one end of the air delivery pipe (30) and extends to the outer wall of the constant temperature drying oven body (1); the air inlet (7) is externally connected to the air outlet of a toxic gas treatment device; the air delivery pipe (30) is provided with a plurality of groups of air outlets (31) and extend to the inner wall of the constant temperature drying oven body (1); The outer wall of the placement plate (14) is sleeved with a gear ring (18), and the gear ring (18) is meshedly connected with a plurality of sets of first linkage gears (27).

2. The constant temperature drying oven for chlorate content determination experiment according to claim 1, characterized in that: The outer wall of the constant temperature drying oven body (1) is provided with a reserved groove (12), an elastic sheet (5) is installed inside the reserved groove (12), a limit block (4) is installed at one end of the elastic sheet (5), and the inner wall of the oven door (8) is provided with a limit groove (11), and the limit groove (11) is movably connected to one end of the limit block (4).

3. The constant temperature drying oven for chlorate content determination experiment according to claim 2, characterized in that: A handle (9) is movably mounted on the outer wall of the box door (8), one end of the handle (9) is movably connected to the inner wall of the limit groove (11), and an exhaust port (6) is provided on one side of the constant temperature drying box body (1), and the exhaust port (6) is externally connected to the air inlet end of the toxic gas treatment device.

4. A method for determining chlorate content, characterized in that: The method is carried out based on the constant temperature drying oven for chlorate content determination experiment described in any one of claims 1 to 3, and the method comprises the following steps: S1: Accurately pipette 5.00 mL of the sample into a 250 mL conical flask containing 20 mL of pure water. First, add hydrogen peroxide in small amounts and multiple times until no bubbles are generated, and add 0.5 mL in excess. Then add 0.5 mL of sulfuric acid, and then add 2 mL of saturated sodium carbonate solution, 20 mL of pure water and several clean glass beads or zeolites. Gently shake the conical flask to mix the solution, and place it in a constant temperature drying oven to heat and boil for 10 minutes. S2: After cooling to room temperature in a constant temperature drying oven, add 20 mL of sulfuric acid solution and 25 mL of ammonium ferrous sulfate standard solution, and heat and boil for 1 min; S3: After cooling again, add 10 mL of phosphoric acid solution and 6-8 drops of sodium diphenylamine sulfonate indicator solution, and titrate with potassium dichromate standard solution. The end point is when the color of the solution changes from colorless to green to purple-blue, and record the amount of potassium dichromate standard titration solution V1; S4: While measuring the sample, use 5.00mL of pure water to perform a blank test according to the same operating steps, and record the amount of potassium dichromate standard titration solution V2.

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