Potentiometric titration online constant-temperature degassing system and degassing method

Abstract

The invention discloses a potentiometric titration online constant-temperature degassing system and method, the system comprises a constant-temperature block and a vacuum cavity, the temperature of a solution is regulated in the constant-temperature block, so that the temperature of the solution leaving the constant-temperature block is controlled to be 20 DEG C, a degassing pipe is arranged in the vacuum cavity, and the solution enters the degassing pipe of the vacuum cavity and then enters the degassing pipe of the vacuum cavity. Due to the fact that the degassing pipe is the expanded polytetrafluoroethylene pipe, gas is allowed to pass while the liquid is blocked, the gas in the liquid can overflow from the expanded polytetrafluoroethylene pipe under the vacuum influence in the vacuum cavity, and the degassing effect is achieved.

Description

Technical Field

[0001] The invention belongs to a potentiometric titration online constant temperature degassing system and a degassing method which can realize online degassing and constant temperature control of a titration solution. Background Art

[0002] A potentiometric titrator is a device that transforms the traditional manual volumetric method into an instrumental method. The traditional manual method uses manual control of liquid addition and visual observation of the sudden change of the indicator to determine the endpoint. Potentiometric titration uses mechanical liquid feeding and uses electrodes to convert the changes before and after the reaction endpoint into changes in electrical signals to determine the endpoint. Potentiometric titration plots the volume of mechanical liquid feeding and the electrode signal into a curve. On the one hand, the subsequent liquid addition can be predicted based on the trend of the curve change, and on the other hand, the equivalence point of the reaction can be calculated using the trend of the curve change. In summary, potentiometric titration is more objective, scientific, and accurate, and is easier to automate. At present, potentiometric titration has been widely used in new energy, petroleum, chemical, food, medicine and other industries.

[0003] However, when using a potentiometric titrator, bubbles often fail to be completely discharged, or bubbles appear in the pump head again after a period of time after the bubbles are discharged. The bubbles in the pump head affect the accuracy of the titration volume. The bubbles in the solution are mainly caused by the precipitation of gas dissolved in the solution due to pressure changes and temperature fluctuations.

[0004] In addition, if a more accurate titration volume is required, potentiometric titration also requires temperature correction of the solution, and the calculation is also cumbersome. GB / T 601-2016 stipulates that the standard temperature is 20°C. At this temperature, the temperature correction coefficient of all solutions is 0. At other temperatures, the correction coefficient needs to be obtained by looking up the table.

[0005] Therefore, a degassing device and method are needed to remove the dissolved gas in the titration solution and reduce the occurrence of bubble precipitation, and the precipitated bubbles cannot affect the solution concentration to avoid interfering with the experimental results. At the same time, in order to reduce the error caused by temperature correction, the solution temperature needs to be kept constant at 20°C. Summary of the invention

[0006] In order to overcome the above problems, the inventors have conducted intensive research and designed an online constant temperature degassing system and method for potentiometric titration, which includes a constant temperature block and a vacuum chamber. The temperature of the solution is controlled in the constant temperature block so that the temperature of the solution leaving the constant temperature block is controlled at 20°C. A degassing tube is provided in the vacuum chamber. After the solution enters the degassing tube of the vacuum chamber, since the degassing tube is an expanded polytetrafluoroethylene tube, the gas is allowed to pass through while blocking the liquid. Under the influence of the vacuum in the vacuum chamber, the gas in the liquid is able to overflow from the expanded polytetrafluoroethylene tube, achieving the degassing effect, thereby completing the present invention.

[0007] Specifically, the object of the present invention is to provide a potentiometric titration online constant temperature degassing system, the system comprising a titration solution inlet 1 and a titration solution outlet 9, the titration solution outlet 9 is connected to a titration pump,

[0008] The system further comprises a constant temperature block 2 and a vacuum chamber 8, a constant temperature tube 3 is arranged in the constant temperature block 2, and a degassing tube 7 is arranged in the vacuum chamber 8;

[0009] The titration solution enters the constant temperature tube 3 through the titration solution inlet 1 to adjust the temperature, then passes through the degassing tube 7 to be degassed, and finally enters the titration pump through the titration solution outlet 9 to perform the subsequent titration procedure.

[0010] Wherein, a Peltier temperature control sheet 4 and a heat exchange sheet 5 are arranged on the constant temperature block 2 , and a heat exchange fan 6 is arranged outside the heat exchange sheet 5 .

[0011] Wherein, the constant temperature block 2 and the heat exchange plate 5 are both made of aluminum metal material;

[0012] Thermally conductive silicone grease is applied between the Peltier temperature control sheet 4 and the constant temperature block 2 or the heat exchange sheet 5 .

[0013] The constant temperature tube 3 is a polytetrafluoroethylene propylene tube with a length of 400 mm, an inner diameter of 1 mm and an outer diameter of 2 mm.

[0014] One end of the thermostatic tube 3 is connected to the titration solution, and the other end is connected to the titration solution inlet 12 of the vacuum chamber.

[0015] Wherein, the degassing tube 7 is an expanded polytetrafluoroethylene tube.

[0016] A vacuum pump 10 is disposed outside the vacuum chamber 8 , and the vacuum chamber 8 is evacuated to a vacuum state by the vacuum pump 10 .

[0017] The flow rate of the vacuum pump 10 is greater than 7 L / min, and the vacuum degree in the vacuum chamber 8 is lower than -9 kPa.

[0018] The expanded polytetrafluoroethylene tube has a length of 300 mm, an inner diameter of 1.5 mm, and an outer diameter of 2.3 mm.

[0019] Preferably, the porosity of the expanded polytetrafluoroethylene tube is 70% to 80%.

[0020] The vacuum chamber 8 is a cavity formed by slotting an aluminum material, and an aluminum vacuum chamber cover plate 14 is buckled on the cavity.

[0021] A sealing ring groove 15 for accommodating and installing a sealing O-ring is provided on the vacuum chamber cover plate 14;

[0022] Preferably, a vacuum chamber interface 11 connected to a vacuum pump 10 is provided on the cavity; a vacuum chamber titration liquid inlet 12 and a vacuum chamber titration liquid outlet 13 respectively connected to the degassing tube 7 are also provided on the cavity.

[0023] Wherein, a thermostatic block cover plate 16 is provided on the thermostatic block 2, and an S-shaped groove is processed on the thermostatic block cover plate 16 as a groove 17 for accommodating the thermostatic tube 3;

[0024] Preferably, the Peltier temperature control sheet 4, the heat exchange sheet 5 and the heat exchange fan 6 are all fixedly mounted on the thermostatic block cover 16;

[0025] Preferably, the vacuum chamber 8, the vacuum chamber cover plate 14 and the constant temperature block cover plate 16 are wrapped with a polyurethane insulation board, and the thickness of the polyurethane insulation board is 10 mm.

[0026] The present invention also provides a potentiometric titration online constant temperature degassing method, which is implemented by the potentiometric titration online constant temperature degassing system described above;

[0027] Preferably, the method comprises the following steps:

[0028] Step 1, start the vacuum pump 10, the Peltier temperature control sheet 4 and the heat exchange fan 6;

[0029] Step 2, introducing the titration solution into the titration solution inlet 1 of the potentiometric titration online constant temperature degassing system;

[0030] The vacuum degree in the vacuum chamber 8 is controlled to a predetermined value by the vacuum pump 10;

[0031] The temperature of the titration solution in the constant temperature tube 3 is controlled at a predetermined temperature by the Peltier temperature control sheet 4 and the heat exchange fan 6 .

[0032] The beneficial effects of the present invention include:

[0033] (1) According to the potentiometric titration online constant temperature degassing system provided by the present invention, the system can realize online constant temperature and degassing of the titration solution, avoid the errors caused by bubble precipitation and temperature correction, and improve the precision and accuracy of the titration analysis;

[0034] (2) The potentiometric titration online constant temperature degassing system provided by the present invention can be connected between the titration pump and the titration night cell to achieve fully automated titration with simple and convenient operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The overall structural schematic diagram of the potentiometric titration online constant temperature degassing system of the present application is shown;

[0036] Figure 2A schematic diagram showing the cross-sectional structure of the vacuum chamber of the potentiometric titration online constant temperature degassing system of the present application is shown;

[0037] Figure 3 A schematic diagram showing the structure of the vacuum chamber cover plate of the potentiometric titration online constant temperature degassing system of the present application is shown;

[0038] Figure 4 A schematic diagram of the thermostatic block cover structure of the potentiometric titration online thermostatic degassing system of the present application is shown.

[0039] Description of Reference Numerals

[0040] 1-Titration solution inlet

[0041] 2- Constant temperature block

[0042] 3- Constant temperature tube

[0043] 4-Peltier temperature control film

[0044] 5-Heat exchanger

[0045] 6- Heat exchange fan

[0046] 7-Degassing tube

[0047] 8-Vacuum chamber

[0048] 9-Titration solution outlet

[0049] 10-Vacuum pump

[0050] 11-Vacuum chamber interface

[0051] 12-Vacuum chamber titration liquid inlet

[0052] 13-Vacuum chamber titration liquid outlet

[0053] 14-Vacuum chamber cover

[0054] 15-Seal ring groove

[0055] 16-Thermostatic block cover

[0056] 17-Groove DETAILED DESCRIPTION

[0057] The present invention will be further described in detail below through the accompanying drawings and embodiments. Through these descriptions, the characteristics and advantages of the present invention will become more clear and distinct.

[0058] The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise noted.

[0059] The present invention provides a potentiometric titration online constant temperature degassing system, such as Figure 1 As shown in FIG. , the system comprises a titration solution inlet 1 and a titration solution outlet 9, wherein the titration solution outlet 9 is connected to a titration pump.

[0060] The system also includes a constant temperature block 2 and a vacuum chamber 8, in which a constant temperature tube 3 is arranged, and in which a degassing tube 7 is arranged; in the present application, the constant temperature block 2 and the vacuum chamber 8 can be an integral structure, or they can be prepared separately and consolidated into one, so as to simplify the overall volume.

[0061] The titration solution enters the thermostatic tube 3 through the titration solution inlet 1 to adjust the temperature, then passes through the degassing tube 7 to be degassed, and finally enters the titration pump through the titration solution outlet 9 to perform the subsequent titration procedure. That is, the thermostatic tube 3 and the degassing tube 7 are connected to each other, and their connection interface can be set outside the thermostatic block 2 and the vacuum chamber.

[0062] In a preferred embodiment, a Peltier temperature control sheet 4 and a heat exchange sheet 5 are provided on the thermostatic block 2, and a heat exchange fan 6 is provided outside the heat exchange sheet 5. The temperature of the thermostatic block 2 is precisely controlled by the Peltier temperature control sheet 4, i.e., for cooling or heating, so as to control the temperature of the liquid in the thermostatic tube in the thermostatic block 2, preferably at 20°C; the heat exchange sheet 5 and the heat exchange fan 6 are used to timely exchange heat for the Peltier temperature control sheet 4, so as to ensure that the Peltier temperature control sheet 4 can continue to work efficiently.

[0063] In a preferred embodiment, the thermostatic block 2 and the heat exchange plate 5 are both made of aluminum metal material; thereby, heat exchange can be performed efficiently to ensure that the solution is controlled at a predetermined temperature; and the aluminum metal material is relatively soft, easy to process, and cost-controlled.

[0064] Thermally conductive silicone grease is applied between the Peltier temperature control sheet 4 and the constant temperature block 2 or the heat exchange sheet 5 so that heat can be conducted more quickly.

[0065] In a preferred embodiment, the thermostatic tube 3 is a polytetrafluoroethylene propylene tube or a polytetrafluoroethylene tube, with a length of 400 mm, an inner diameter of 1 mm, and an outer diameter of 2 mm. The applicant has found that only when the thermostatic tube 3 is set to the above length and thickness can the solution be continuously controlled at 20° C. at any ambient temperature.

[0066] According to the single-layer cylindrical wall constant temperature heat conduction model, the constant temperature outflow of the solution can be achieved when the following equation is satisfied:

[0067]

[0068] Where: λ represents the thermal conductivity of the material, with the unit of watt per kelvin per meter (W / K / m);

[0069] r 2 Indicates the outer radius of the tube, in meters (m);

[0070] r 1 Indicates the inner radius of the tube, in meters (m);

[0071] u represents flow rate in kilograms per second (kg / s);

[0072] c represents the specific heat of the solution, with the unit being joule per kilojoule (J / K / kg);

[0073] Substituting the specific heat capacity of water, the design can meet the constant temperature requirement for flow rates below 10mL / min. This speed is basically equivalent to the fastest cleaning speed currently available. If a higher flow rate is required, the tube length can be appropriately extended or the wall thickness can be reduced.

[0074] In a preferred embodiment, one end of the thermostatic tube 3 is connected to the titration solution, and the other end is connected to the vacuum chamber titration solution inlet 12. Thus, the liquid temperature in the titration solution can be controlled to a predetermined temperature and then degassing can be performed immediately.

[0075] In a preferred embodiment, the degassing tube 7 is an expanded polytetrafluoroethylene tube, so as to fully utilize the gas-liquid separation characteristics of the expanded polytetrafluoroethylene tube for degassing.

[0076] A vacuum pump 10 is disposed outside the vacuum chamber 8 , and the vacuum chamber 8 is evacuated to a vacuum state by the vacuum pump 10 , thereby improving the efficiency of the degassing process.

[0077] Preferably, the flow rate of the vacuum pump 10 is greater than 7 L / min, and the vacuum degree in the vacuum chamber 8 is lower than -9 kPa. The applicant has found that when the vacuum degree in the vacuum chamber 8 is lower than -9 kPa, it can continuously cause other substances in the solution to overflow from the degassing tube 7, and no bubbles will appear in the subsequent titration process, thereby ensuring the titration effect.

[0078] In a preferred embodiment, the expanded polytetrafluoroethylene tube has a length of 300 mm, an inner diameter of 1.5 mm, and an outer diameter of 2.3 mm;

[0079] At room temperature and pressure, the saturated dissolved oxygen and saturated dissolved nitrogen of the solution are about 8mg / kg and 18mg / kg respectively. When the temperature rises, the value decreases, and vice versa. When the pressure increases, the value increases, and vice versa decreases. When the solubility of oxygen or nitrogen is greater than its saturated solubility, bubbles will precipitate. Assuming that the size of the bubble is 2mm, and this bubble is produced by the precipitation of dissolved oxygen or nitrogen in the 10mL burette solution, it is easy to deduce that the concentration change corresponding to this bubble is about 0.6mg / kg.

[0080] Saturated carbon dioxide aqueous solution was used as the simulated solution, and flowed through the above degassing system at a speed of 10mL / min. The solution before and after degassing was taken and the dissolved carbon dioxide concentration was measured using 0.01mol / L sodium hydroxide standard titration solution. The results showed that the above degassing system can degas 1632mg / kg saturated carbon dioxide aqueous solution to less than 3mg / kg. The above data fully proves that the system has good degassing performance.

[0081] Preferably, the porosity of the expanded polytetrafluoroethylene tube is 70% to 80%.

[0082] In a preferred embodiment, the vacuum chamber 8 is a cavity formed by slotting an aluminum material, and an aluminum vacuum chamber cover plate 14 is buckled on the cavity.

[0083] A sealing ring groove 15 for accommodating and installing a sealing O-ring is provided on the vacuum chamber cover plate 14;

[0084] Preferably, a vacuum chamber interface 11 connected to a vacuum pump 10 is provided on the cavity; a vacuum chamber titration liquid inlet 12 and a vacuum chamber titration liquid outlet 13 respectively connected to the degassing tube 7 are also provided on the cavity.

[0085] Preferably, if Figure 2 As shown in the figure, a groove with a length of 80 mm, a width of 72 mm, and a depth of 40 mm is machined on an aluminum material with a length of 104 mm, a width of 94 mm, and a height of 60 mm to serve as a vacuum chamber 8. An M6 interface is machined on the left side to serve as a vacuum chamber interface 11 to connect to a vacuum pump. Two M6 interfaces are machined on the right side to serve as the vacuum chamber titration liquid inlet 12 and the vacuum chamber titration liquid outlet 13, respectively. The upper surface of the groove is machined flat and fits tightly with the sealing O-ring on the vacuum chamber cover plate 14 to prevent air leakage. Figure 3 As shown in the figure, the vacuum chamber cover plate 14 is made of aluminum material with a length of 104mm, a cavity width of 94mm, and a height of 5mm. A sealing ring groove 15 is processed on its upper surface, with a width of 2mm and a depth of 1.6mm. The sealing O-ring is made of EPDM rubber, with an outer diameter of 106mm and a wire diameter of 2mm. An M3 threaded hole is processed at each of the four corners of the vacuum chamber cover plate 14, and the sealing O-ring is extruded in cooperation with the vacuum chamber 8. The vacuum chamber titration liquid inlet 12 and the vacuum chamber titration liquid outlet 13 are connected using a degassing tube 7, and the M6 ​​interface is also used to achieve a sealed connection.

[0086] In a preferred embodiment, a thermostatic block cover plate 16 is provided on the thermostatic block 2, and an S-shaped groove is processed on the thermostatic block cover plate 16 as a groove 17 for accommodating the thermostatic tube 3;

[0087] Preferably, the Peltier temperature control sheet 4, the heat exchange sheet 5 and the heat exchange fan 6 are all fixedly mounted on the thermostatic block cover 16;

[0088] Preferably, the vacuum chamber 8, the vacuum chamber cover plate 14 and the constant temperature block cover plate 16 are wrapped with a polyurethane insulation board, and the thickness of the polyurethane insulation board is 10 mm.

[0089] Preferably, the thermostatic block cover 16 is made of aluminum material with a block width of 104 mm and a height of 94 mm. An M3 threaded hole is processed at each of the four corners of the thermostatic block cover 16 to cooperate with the vacuum chamber 8 to extrude the thermostatic tube 3. An S-shaped groove is processed on the thermostatic block cover 16 as a groove 17 for accommodating the thermostatic tube, and the groove size is 2.2 mm wide and 2.2 mm deep.

[0090] The present invention also provides a potentiometric titration online constant temperature degassing method, which is implemented by the potentiometric titration online constant temperature degassing system described above; preferably, the method comprises the following steps:

[0091] Step 1, start the vacuum pump 10, the Peltier temperature control sheet 4 and the heat exchange fan 6;

[0092] Step 2, introducing the titration solution into the titration solution inlet 1 of the potentiometric titration online constant temperature degassing system;

[0093] The vacuum degree in the vacuum chamber 8 is controlled to a predetermined value by the vacuum pump 10;

[0094] The temperature of the titration solution in the thermostatic tube 3 is controlled at a predetermined temperature by the Peltier temperature control sheet 4 and the heat exchange fan 6.

[0095] Example

[0096] The carbon dioxide content in the saturated carbon dioxide aqueous solution at 20 degrees Celsius is 1632 mg / kg, which is used as the titration solution; Figure 1 , Figure 2 , Figure 3 , Figure 4 The potentiometric titration online constant temperature degassing system shown in the figure comprises a constant temperature block 2 and a vacuum chamber 8, a constant temperature tube 3 is arranged in the constant temperature block 2, and a degassing tube 7 is arranged in the vacuum chamber 8; the titration solution enters the constant temperature tube 3 through the titration solution inlet 1 to adjust the temperature, and then enters the degassing tube 7 to be degassed.

[0097] The outside of the degassing tube 7 is a vacuum chamber 8; the degassing tube 7 is an expanded polytetrafluoroethylene tube with a length of 300 mm, an inner diameter of 1.5 mm, and an outer diameter of 2.3 mm; the porosity of the degassing tube 7 is 75%, and a vacuum pump 10 is connected to the vacuum chamber 8;

[0098] The constant temperature block 2 is provided with a Peltier temperature control sheet 4 and a heat exchange sheet 5 , and a heat exchange fan 6 is provided outside the heat exchange sheet 5 .

[0099] Step 1, start the vacuum pump 10 to make the vacuum degree of the vacuum chamber 8 be -10 kPa;

[0100] Start the Peltier temperature control sheet 4 and the heat exchange fan 6 to control the temperature of the titration solution in the thermostatic tube 3 at 20 degrees Celsius;

[0101] Step 2, the titration solution is introduced into the titration solution inlet of the potentiometric titration online constant temperature degassing system, the titration solution enters the constant temperature tube 3 through the titration solution inlet to adjust the temperature, the temperature is controlled at 20 degrees Celsius, and then passes through the degassing tube 7 to be degassed, and finally reaches the titration solution outlet, and the treated titration solution is obtained from the titration solution outlet;

[0102] Step 3, using 0.01 mol / L sodium hydroxide standard titration solution to measure the carbon dioxide content in the treated titration solution to be 2.7 mg / kg.

[0103] Comparative Example 1

[0104] The carbon dioxide content in the saturated carbon dioxide aqueous solution at 20 degrees Celsius is 1632 mg / kg, which is used as the titration solution; Figure 1 , Figure 2 , Figure 3 , Figure 4 The potentiometric titration online constant temperature degassing system shown in the figure comprises a constant temperature block 2 and a vacuum chamber 8, a constant temperature tube 3 is arranged in the constant temperature block 2, and a degassing tube 7 is arranged in the vacuum chamber 8; the titration solution enters the constant temperature tube 3 through the titration solution inlet 1 to adjust the temperature, and then enters the degassing tube 7 to be degassed.

[0105] The outside of the degassing tube 7 is a vacuum chamber 8; the degassing tube 7 is a microporous polyethylene tube with a length of 300 mm, an inner diameter of 1.5 mm, and an outer diameter of 2.3 mm; the porosity of the degassing tube 7 is 75%, and a vacuum pump 10 is connected to the vacuum chamber 8;

[0106] The constant temperature block 2 is provided with a Peltier temperature control sheet 4 and a heat exchange sheet 5 , and a heat exchange fan 6 is provided outside the heat exchange sheet 5 .

[0107] Step 1, start the vacuum pump 10 to make the vacuum degree of the vacuum chamber 8 be -10 kPa;

[0108] The Peltier temperature control sheet 4 and the heat exchange fan 6 are started to control the temperature of the titration solution in the constant temperature tube 3 at 20 degrees Celsius.

[0109] Step 2, the titration solution is introduced into the titration solution inlet of the potentiometric titration online constant temperature degassing system, the titration solution enters the constant temperature tube 3 through the titration solution inlet to adjust the temperature, the temperature is controlled at 20 degrees Celsius, and then passes through the degassing tube 7 to be degassed, and finally reaches the titration solution outlet, and the treated titration solution is obtained from the titration solution outlet;

[0110] Step 3, using 0.01 mol / L sodium hydroxide standard titration solution to measure the carbon dioxide content in the treated titration solution to be 30.2 mg / kg.

[0111] Comparative Example 2

[0112] The carbon dioxide content in the saturated carbon dioxide aqueous solution at 20 degrees Celsius is 1632 mg / kg, which is used as the titration solution; Figure 1 , Figure 2 , Figure 3 , Figure 4 The potentiometric titration online constant temperature degassing system shown in the figure comprises a constant temperature block 2 and a vacuum chamber 8, a constant temperature tube 3 is arranged in the constant temperature block 2, and a degassing tube 7 is arranged in the vacuum chamber 8; the titration solution enters the constant temperature tube 3 through the titration solution inlet 1 to adjust the temperature, and then enters the degassing tube 7 to be degassed.

[0113] The outside of the degassing tube 7 is a vacuum chamber 8; the degassing tube 7 is an expanded polytetrafluoroethylene tube with a length of 300 mm, an inner diameter of 2.0 mm, and an outer diameter of 3.0 mm; the porosity of the degassing tube 7 is 75%, and a vacuum pump 10 is connected to the vacuum chamber 8;

[0114] The constant temperature block 2 is provided with a Peltier temperature control sheet 4 and a heat exchange sheet 5 , and a heat exchange fan 6 is provided outside the heat exchange sheet 5 .

[0115] Step 1, start the vacuum pump 10 to make the vacuum degree of the vacuum chamber 8 be -10 kPa;

[0116] The Peltier temperature control sheet 4 and the heat exchange fan 6 are started to control the temperature of the titration solution in the constant temperature tube 3 at 20 degrees Celsius.

[0117] Step 2, the titration solution is introduced into the titration solution inlet of the potentiometric titration online constant temperature degassing system, the titration solution enters the constant temperature tube 3 through the titration solution inlet to adjust the temperature, the temperature is controlled at 20 degrees Celsius, and then passes through the degassing tube 7 to be degassed, and finally reaches the titration solution outlet, and the treated titration solution is obtained from the titration solution outlet;

[0118] Step 3, using 0.01 mol / L sodium hydroxide standard titration solution to measure the carbon dioxide content in the treated titration solution to be 22.1 mg / kg.

[0119] Comparative Example 3

[0120] The carbon dioxide content in the saturated carbon dioxide aqueous solution at 20 degrees Celsius is 1632 mg / kg, which is used as the titration solution; Figure 1 , Figure 2 , Figure 3 , Figure 4 The potentiometric titration online constant temperature degassing system shown in the figure comprises a constant temperature block 2 and a vacuum chamber 8, a constant temperature tube 3 is arranged in the constant temperature block 2, and a degassing tube 7 is arranged in the vacuum chamber 8; the titration solution enters the constant temperature tube 3 through the titration solution inlet 1 to adjust the temperature, and then enters the degassing tube 7 to be degassed.

[0121] The outside of the degassing tube 7 is a vacuum chamber 8; the degassing tube 7 is an expanded polytetrafluoroethylene tube with a length of 300 mm, an inner diameter of 1.5 mm, and an outer diameter of 2.3 mm; the porosity of the degassing tube 7 is 60%, and a vacuum pump 10 is connected to the vacuum chamber 8;

[0122] The constant temperature block 2 is provided with a Peltier temperature control sheet 4 and a heat exchange sheet 5 , and a heat exchange fan 6 is provided outside the heat exchange sheet 5 .

[0123] Step 1, start the vacuum pump 10 to make the vacuum degree of the vacuum chamber 8 be -10 kPa;

[0124] The Peltier temperature control sheet 4 and the heat exchange fan 6 are started to control the temperature of the titration solution in the constant temperature tube 3 at 20 degrees Celsius.

[0125] Step 2, the titration solution is introduced into the titration solution inlet of the potentiometric titration online constant temperature degassing system, the titration solution enters the constant temperature tube 3 through the titration solution inlet to adjust the temperature, the temperature is controlled at 20 degrees Celsius, and then passes through the degassing tube 7 to be degassed, and finally reaches the titration solution outlet, and the treated titration solution is obtained from the titration solution outlet;

[0126] Step 3, using 0.01 mol / L sodium hydroxide standard titration solution to measure the carbon dioxide content in the treated titration solution to be 25.2 mg / kg.

[0127] Comparative Example 4

[0128] The carbon dioxide content in the saturated carbon dioxide aqueous solution at 20 degrees Celsius is 1632 mg / kg, which is used as the titration solution; Figure 1 , Figure 2 , Figure 3 , Figure 4The potentiometric titration online constant temperature degassing system shown in the figure comprises a constant temperature block 2 and a vacuum chamber 8, a constant temperature tube 3 is arranged in the constant temperature block 2, and a degassing tube 7 is arranged in the vacuum chamber 8; the titration solution enters the constant temperature tube 3 through the titration solution inlet 1 to adjust the temperature, and then enters the degassing tube 7 to be degassed.

[0129] The degassing tube 7 is an expanded fluororubber tube with a length of 300 mm, an inner diameter of 1.5 mm, and an outer diameter of 2.3 mm; the porosity of the degassing tube 7 is 75%, and a vacuum pump 10 is connected to the vacuum chamber 8;

[0130] The constant temperature block 2 is provided with a Peltier temperature control sheet 4 and a heat exchange sheet 5 , and a heat exchange fan 6 is provided outside the heat exchange sheet 5 .

[0131] Step 1, start the vacuum pump 10 to make the vacuum degree of the vacuum chamber 8 be -10 kPa;

[0132] The Peltier temperature control sheet 4 and the heat exchange fan 6 are started to control the temperature of the titration solution in the constant temperature tube 3 at 15 degrees Celsius.

[0133] Step 2, the titration solution is introduced into the titration solution inlet of the potentiometric titration online constant temperature degassing system, the titration solution enters the constant temperature tube 3 through the titration solution inlet to adjust the temperature, the temperature is controlled at 15 degrees Celsius, and then passes through the degassing tube 7 to be degassed, and finally reaches the titration solution outlet, and the treated titration solution is obtained from the titration solution outlet;

[0134] Step 3, using 0.01 mol / L sodium hydroxide standard titration solution to measure the carbon dioxide content in the treated titration solution to be 562 mg / kg.

[0135] Comparative Example 5

[0136] The carbon dioxide content in the saturated carbon dioxide aqueous solution at 20 degrees Celsius is 1632 mg / kg, which is used as the titration solution; Figure 1 , Figure 2 , Figure 3 , Figure 4 The potentiometric titration online constant temperature degassing system shown in the figure comprises a constant temperature block 2 and a vacuum chamber 8, a constant temperature tube 3 is arranged in the constant temperature block 2, and a degassing tube 7 is arranged in the vacuum chamber 8; the titration solution enters the constant temperature tube 3 through the titration solution inlet 1 to adjust the temperature, and then enters the degassing tube 7 to be degassed.

[0137] The outside of the degassing tube 7 is a vacuum chamber 8; the degassing tube 7 is an expanded polytetrafluoroethylene tube with a length of 300 mm, an inner diameter of 1.5 mm, and an outer diameter of 3.0 mm; the porosity of the degassing tube 7 is 75%, and a vacuum pump 10 is connected to the vacuum chamber 8;

[0138] The constant temperature block 2 is provided with a Peltier temperature control sheet 4 and a heat exchange sheet 5 , and a heat exchange fan 6 is provided outside the heat exchange sheet 5 .

[0139] Step 1, start the vacuum pump 10 to make the vacuum degree of the vacuum chamber 8 be -5 kPa;

[0140] The Peltier temperature control sheet 4 and the heat exchange fan 6 are started to control the temperature of the titration solution in the constant temperature tube 3 at 20 degrees Celsius.

[0141] Step 2, the titration solution is introduced into the titration solution inlet of the potentiometric titration online constant temperature degassing system, the titration solution enters the constant temperature tube 3 through the titration solution inlet to adjust the temperature, the temperature is controlled at 20 degrees Celsius, and then passes through the degassing tube 7 to be degassed, and finally reaches the titration solution outlet, and the treated titration solution is obtained from the titration solution outlet;

[0142] Step 3, using 0.01 mol / L sodium hydroxide standard titration solution to measure the carbon dioxide content in the treated titration solution to be 128 mg / kg.

[0143] It can be seen from the above embodiments and comparative examples that the specific parameter information in the potentiometric titration online constant temperature degassing system provided in the present application are all optimal parameters, and the comprehensive configuration can achieve the best degassing effect.

[0144] The present invention has been described above in conjunction with preferred embodiments, but these embodiments are only exemplary and serve only as an illustration. On this basis, the present invention may be subjected to a variety of substitutions and improvements, all of which fall within the scope of protection of the present invention.

Claims

1. A potentiometric titration online constant temperature degassing system, characterized in that: The system comprises a titration solution inlet (1) and a titration solution outlet (9), wherein the titration solution outlet (9) is connected to a titration pump. The system also includes a constant temperature block (2) and a vacuum chamber (8), a constant temperature tube (3) is arranged in the constant temperature block (2), and a degassing tube (7) is arranged in the vacuum chamber (8); The titration solution enters the constant temperature tube (3) through the titration solution inlet (1) to adjust the temperature, then passes through the degassing tube (7) to be degassed, and finally enters the titration pump through the titration solution outlet (9) to perform the subsequent titration procedure.

2. The potentiometric titration online constant temperature degassing system according to claim 1, characterized in that: A Peltier temperature control plate (4) and a heat exchange plate (5) are arranged on the constant temperature block (2), and a heat exchange fan (6) is arranged outside the heat exchange plate (5).

3. The potentiometric titration online constant temperature degassing system according to claim 2, characterized in that: The constant temperature block (2) and the heat exchange plate (5) are both made of aluminum metal material; Thermal conductive silicone grease is applied between the Peltier temperature control sheet (4) and the constant temperature block (2) or the heat exchange sheet (5).

4. The potentiometric titration online constant temperature degassing system according to claim 1, characterized in that: The constant temperature tube (3) is a polyperfluoroethylene propylene tube with a length of 400 mm, an inner diameter of 1 mm and an outer diameter of 2 mm.

5. The potentiometric titration online constant temperature degassing system according to claim 1, characterized in that: One end of the thermostatic tube (3) is connected to the titration solution, and the other end is connected to the vacuum chamber titration solution inlet (12).

6. The potentiometric titration online constant temperature degassing system according to claim 1, characterized in that: The degassing tube (7) is an expanded polytetrafluoroethylene tube. A vacuum pump (10) is arranged outside the vacuum chamber (8), and the vacuum chamber (8) is evacuated to a vacuum state by the vacuum pump (10); Preferably, the flow rate of the vacuum pump (10) is greater than 7 L / min, and the vacuum degree in the vacuum chamber (8) is lower than -9 kPa.

7. The potentiometric titration online constant temperature degassing system according to claim 6, characterized in that: The expanded polytetrafluoroethylene tube has a length of 300 mm, an inner diameter of 1.5 mm, and an outer diameter of 2.3 mm; Preferably, the porosity of the expanded polytetrafluoroethylene tube is 70% to 80%.

8. The potentiometric titration online constant temperature degassing system according to claim 1, characterized in that: The vacuum chamber (8) is a cavity formed by slotting an aluminum material, and an aluminum vacuum chamber cover plate (14) is buckled on the cavity. A sealing ring groove (15) for accommodating and installing a sealing O-ring is provided on the vacuum chamber cover plate (14); Preferably, a vacuum chamber interface (11) connected to a vacuum pump (10) is provided on the cavity; a vacuum chamber titration liquid inlet (12) and a vacuum chamber titration liquid outlet (13) respectively connected to a degassing tube (7) are also provided on the cavity.

9. The potentiometric titration online constant temperature degassing system according to claim 8, characterized in that: A thermostatic block cover plate (16) is provided on the thermostatic block (2), and an S-shaped groove is machined on the thermostatic block cover plate (16) as a groove (17) for accommodating the thermostatic tube (3); Preferably, the Peltier temperature control sheet (4), the heat exchange sheet (5) and the heat exchange fan (6) are all fixedly mounted on the thermostatic block cover plate (16); Preferably, the vacuum chamber (8), the vacuum chamber cover plate (14) and the constant temperature block cover plate (16) are externally wrapped with a polyurethane insulation board, and the thickness of the polyurethane insulation board is 10 mm.

10. A potentiometric titration online constant temperature degassing method, characterized in that: The method is implemented by the potentiometric titration online constant temperature degassing system according to any one of claims 1 to 9; Preferably, the method comprises the following steps: Step 1, starting the vacuum pump (10), the Peltier temperature control plate (4) and the heat exchange fan (6); Step 2, introducing the titration solution into the titration solution inlet (1) of the potentiometric titration online constant temperature degassing system; Controlling the vacuum degree in the vacuum chamber (8) to a predetermined value by means of a vacuum pump (10); The temperature of the titration solution in the constant temperature tube (3) is controlled at a predetermined temperature by means of a Peltier temperature control sheet (4) and a heat exchange fan (6).

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