Efficient receiving reaction device suitable for Kjeldahl apparatus and Kjeldahl apparatus

Abstract

The invention belongs to the technical field of Kjeldahl determination. The efficient receiving reaction device comprises a receiving cup, a receiving cup cover, a stirring motor and a receiving cup base, the stirring motor is fixed to the receiving cup cover, a stirring rod of the stirring motor extends into the receiving cup, and the receiving cup is fixed in the receiving cup base; a receiving liquid inlet hole and a titration acid hole are formed in the receiving cup cover, a receiving liquid inlet pipe penetrates through the receiving liquid inlet hole and extends into the receiving cup, and a first connecting line is formed between the central point of the receiving liquid inlet hole and the central point of the receiving cup cover; the included angle between the acid titration hole and a second connecting line between the central point of the acid titration hole and the central point of the receiving cup cover is less than or equal to 90 degrees; no matter whether the stirring motor rotates clockwise or anticlockwise, the receiving liquid and the titration acid can be quickly mixed and reacted, so that the measurement fluctuation of the colorimetric sensor and the potential sensor is reduced, and the detection efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of Kjeldahl nitrogen determination, and in particular to a high-efficiency receiving reaction device suitable for a Kjeldahl nitrogen determination instrument and the Kjeldahl nitrogen determination instrument. Background Art

[0002] The statements in this section merely provide background art related to the present invention and do not necessarily constitute prior art.

[0003] The Kjeldahl method is a method for measuring the protein content in a sample based on nitrogen. The sample is digested with concentrated acid to convert the organic nitrogen in the sample into inorganic ammonium salts. The ammonium salts are then converted into ammonia under alkaline conditions. The ammonia is distilled out with water vapor and absorbed by excess acid solution. The ammonia is then titrated with standard (concentration) acid. The amount of nitrogen in the sample can be calculated based on the consumed standard (concentration) acid.

[0004] The inventors have found that the existing Kjeldahl nitrogen determination receiving reaction device has the following problems: (1) The titrating acid tube is nested in the receiving liquid pipeline. Since the receiving liquid is a discontinuous liquid, the titrating acid cannot react quickly with the liquid to be detected in the receiving cup, which is easy to cause fluctuations in the readings of the color sensor (or potentiometric sensor), which is not conducive to rapid titration and thus affects the detection efficiency; (2) The receiving liquid pipeline is immersed below the liquid level, which is easy to cause back suction and pipeline residue; (3) The receiving cup is not easy to disassemble and difficult to clean; (4) The receiving cup is of ordinary flat bottom or conical design, which is not conducive to rapid liquid collection detection; (5) The titrating acid is easy to diffuse into the receiving liquid, affecting the accuracy of the titration. Summary of the invention

[0005] In order to solve the shortcomings of the prior art, the present invention provides a high-efficiency receiving reaction device suitable for a Kjeldahl nitrogen analyzer and a Kjeldahl nitrogen analyzer. The receiving liquid inlet hole, the titrated acid hole and the stirring motor on the receiving cup cover are scientifically arranged. Regardless of whether the stirring motor rotates clockwise or counterclockwise, the receiving liquid and the titrated acid can be quickly mixed and reacted, which greatly improves the mixing rate, reduces the measurement fluctuation of the colorimetric sensor and the potentiometric sensor, and thus improves the detection efficiency.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a high-efficiency receiving reaction device suitable for a Kjeldahl nitrogen analyzer.

[0008] An efficient receiving reaction device suitable for a Kjeldahl nitrogen analyzer comprises: a receiving cup, a receiving cup cover, a stirring motor, and a receiving cup seat, wherein the stirring motor is fixed on the receiving cup cover, and a stirring rod of the stirring motor is inserted into the receiving cup, and the receiving cup is fixed in the receiving cup seat;

[0009] The receiving cup cover is provided with a receiving liquid inlet hole and a titrating acid hole, and the receiving liquid inlet pipe passes through the receiving liquid inlet hole and extends into the interior of the receiving cup. The angle between the first connecting line between the center point of the receiving liquid inlet hole and the center point of the receiving cup cover and the second connecting line between the center point of the titrating acid hole and the center point of the receiving cup cover is ≤90°.

[0010] As a further limitation of the first aspect of the present invention, the receiving cup cover is provided with a boric acid liquid inlet hole and an electrode fixing hole, and the electrode fixing hole is used for inserting a potential sensor.

[0011] As a further preferred embodiment of the first aspect of the present invention, the angle between the first connecting line and the second connecting line is 45°.

[0012] As a further preferred embodiment of the first aspect of the present invention, a stirring impeller is connected to the stirring rod, and the distance between the titration acid hole and the center line of the stirring rod and the distance between the receiving liquid inlet hole and the center line of the stirring rod are respectively greater than the diameter of the stirring impeller.

[0013] As a further limitation of the first aspect of the present invention, the bottom of the receiving cup is connected to a straight pipe section with an inner diameter smaller than the body of the receiving cup, and a sealing ring is sleeved on the outer side of the straight pipe section, and the sealing ring is embedded in the sealing ring groove of the receiving cup seat.

[0014] As a further limitation of the first aspect of the present invention, the point light source and the color sensor are both fixed on the receiving cup and arranged opposite to the straight tube section.

[0015] As a further limitation of the first aspect of the present invention, the diameter of the point light source ≤ the diameter of the straight tube section ≤ the diameter of the receiving cup.

[0016] As a further limitation of the first aspect of the present invention, the sealing ring groove includes a first sealing ring groove and a second sealing ring groove arranged vertically, and the point light source is located between the first sealing ring groove and the second sealing ring groove.

[0017] As a further limitation of the first aspect of the present invention, a drainage hole is provided at the bottom of the straight pipe section, and the drainage hole is communicated with the drainage channel.

[0018] As a further limitation of the first aspect of the present invention, a through hole is formed on the upper side wall of the portion of the receiving liquid inlet tube that extends into the receiving cup; an anti-diffusion device (such as a one-way valve) is installed at the outlet of the titrated acid inlet tube, which is in a conductive state in the direction from the titrated acid to the receiving liquid, thereby preventing mutual diffusion between the receiving liquid and the titrated acid and improving the accuracy of the detection results.

[0019] In a second aspect, the present invention provides a working method of the high-efficiency receiving reaction device suitable for the Kjeldahl nitrogen analyzer according to the first aspect of the present invention, which uses a potential sensor inserted into the receiving cup through the receiving cup cover for detection, including the following process:

[0020] The stirring motor is turned on, and the boric acid solution with the indicator added enters the receiving cup through the boric acid inlet hole and the boric acid inlet tube;

[0021] The receiving liquid enters the receiving cup through the receiving liquid inlet hole and the receiving liquid receiving tube and reacts with the boric acid solution in the receiving cup. At this time, the potential in the receiving cup changes. The potential sensor detects the potential change and feeds it back to the sample pushing module.

[0022] The sample pushing module pushes a certain amount of titrating acid into the receiving cup through the titrating acid hole and the titrating acid inlet tube according to the set judgment logic. The titrating acid solution reacts with the solution in the receiving cup, and the corresponding potential changes. This titration process is repeated until the experiment is completed.

[0023] After the process is finished, the waste liquid is discharged through the drain hole, and the receiving cup is directly removed from the receiving cup seat for cleaning.

[0024] In a third aspect, the present invention provides a working method of the efficient receiving reaction device suitable for a Kjeldahl nitrogen analyzer according to the first aspect of the present invention, comprising the following process:

[0025] The stirring motor is turned on, and the boric acid solution with the indicator added enters the receiving cup through the boric acid inlet hole and the boric acid inlet tube;

[0026] The receiving liquid enters the receiving cup through the receiving liquid inlet hole and the receiving liquid receiving tube and reacts with the boric acid solution in the receiving cup. At this time, the color of the solution in the receiving cup changes. The color sensor detects the color change and feeds it back to the sample pushing module.

[0027] The sample pushing module pushes a certain amount of titrating acid into the receiving cup through the titrating acid hole and the titrating acid inlet tube according to the set judgment logic. The titrating acid solution reacts with the solution in the receiving cup, and the corresponding color changes. This titration process is repeated until the end of the experiment. After the end, the waste liquid is discharged through the drain hole, and the receiving cup is directly removed from the receiving cup seat for cleaning.

[0028] In a fourth aspect, the present invention provides a Kjeldahl nitrogen analyzer, comprising the high-efficiency receiving reaction device suitable for the Kjeldahl nitrogen analyzer described in the first aspect of the present invention.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The present invention innovatively develops a high-efficiency receiving reaction device suitable for Kjeldahl nitrogen analyzer. The angle formed by the center of the receiving liquid inlet hole, the center of the titrated acid hole and the center point of the receiving cup cover is ≤90°. The receiving liquid inlet hole, the titrated acid hole and the stirring motor on the receiving cup cover are scientifically arranged. Regardless of whether the stirring motor rotates clockwise or counterclockwise, the receiving liquid and the titrated acid can quickly mix and react, which greatly improves the mixing rate, reduces the measurement fluctuation of the colorimetric sensor and the potentiometric sensor, and thus improves the detection efficiency.

[0031] 2. The present invention innovatively develops a high-efficiency receiving reaction device suitable for a Kjeldahl nitrogen analyzer. A stirring motor is provided, and the stirring motor is fixed on the upper part of the receiving cup cover. The stirring rod is inserted into the receiving cup to stir the liquid to be tested and the titrated acid in the receiving cup, thereby greatly improving the reaction efficiency.

[0032] 3. A straight tube section is provided at the bottom of the receiving cup of the present invention, and the inner diameter of the straight tube section is smaller than the inner diameter of the receiving cup body, the point light source diameter ≤ the straight tube section diameter ≤ the receiving cup diameter, and the point light source is arranged on the upper part of the second sealing ring, which facilitates the rapid sampling of the color sensor and greatly improves the test efficiency.

[0033] 4. The sealing ring of the present invention is located in the sealing ring groove of the receiving cup seat, which is convenient for quick removal of the receiving cup, and a small hole is provided at the top of the receiving liquid inlet pipe, which can effectively prevent back suction and reduce pipeline residue.

[0034] 5. The stirring rod of the present invention is connected to a stirring impeller. The distance between the titration acid hole and the center line of the stirring rod, and the distance between the receiving liquid inlet hole and the center line of the stirring rod are respectively greater than the diameter of the stirring impeller. The flow rate of the liquid to be tested near the tip of the stirring impeller is the highest, which is convenient for rapid mixing of the titration acid and the receiving liquid.

[0035] 6. The outlet of the titrated acid inlet pipe of the present invention is equipped with an anti-diffusion device (such as a one-way valve), which is in a conductive state in the direction from the titrated acid to the receiving liquid, thereby preventing mutual diffusion between the receiving liquid and the titrated acid and improving the accuracy of the test results.

[0036] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0038] Figure 1 A schematic diagram of a high-efficiency receiving reaction device suitable for a Kjeldahl nitrogen analyzer provided by the present invention;

[0039] Figure 2 A schematic diagram of a receiving cup cover provided by the present invention;

[0040] Figure 3 An exploded diagram of a high-efficiency receiving reaction device suitable for a Kjeldahl nitrogen analyzer provided by the present invention;

[0041] Figure 4 A cross-sectional view of a high-efficiency receiving reaction device suitable for a Kjeldahl nitrogen analyzer provided by the present invention;

[0042] Among them, 1. stirring motor; 2. receiving cup cover; 3. receiving cup; 4. receiving cup base; 5. stirring rod; 6. receiving liquid inlet pipe; 7. point light source; 8. first fixing piece; 9. second fixing piece; 10. color sensor; 11. first sealing ring groove; 12. second sealing ring groove; 13. drainage hole; 14. drainage channel; 15. titration acid hole; 16. receiving liquid inlet hole; 17. electrode fixing hole; 18. boric acid inlet hole; 19. straight pipe section; DETAILED DESCRIPTION

[0043] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0044] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0045] In this implementation, an efficient receiving reaction device suitable for Kjeldahl nitrogen analyzer is proposed, such as Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, it includes: a receiving cup 3, a receiving cup cover 2, a stirring motor 1 and a receiving cup base 4, wherein the stirring motor 1 is fixed on the receiving cup cover 2 (can be fixed by snap connection or bolts), and a stirring rod 5 of the stirring motor 1 is inserted into the receiving cup 3, and the stirring motor 1 is used to stir the liquid to be tested and the titrated acid in the receiving cup 3;

[0046] The receiving cup cover 2 is provided with a receiving liquid inlet hole 16, a titrated acid hole 15 and a boric acid inlet hole 18, and the receiving liquid inlet pipe 6 penetrates through the receiving liquid inlet hole into the receiving cup 3, and the angle between the first connecting line between the center point of the receiving cup inlet hole 16 and the center point of the receiving cup cover 2 and the second connecting line between the center point of the titrated acid hole 15 and the center point of the receiving cup cover 2 is ≤90°; in this implementation, preferably, the angle between the first connecting line and the second connecting line is 45°, and the receiving cup inlet hole 16 and the titrated acid hole 15 are closely located, regardless of whether the stirring motor 1 rotates clockwise or counterclockwise, the receiving liquid and the titrated acid can quickly mix and react (when the distance is too far, when the titrated acid discharge amount is small, the titrated acid micelles are not easy to contact with the incoming liquid and are easily dispersed).

[0047] In this implementation, preferably, the receiving cup cover 2 is provided with a boric acid inlet hole 18 and an electrode fixing hole 17 for the inlet of boric acid and the insertion of the potential sensor.

[0048] In this implementation, preferably, the bottom of the receiving cup 3 is conical, and the bottom of the receiving cup 3 is connected to a straight pipe section 19 whose diameter is smaller than the body of the receiving cup 3 . A sealing ring is sleeved on the outer side of the straight pipe section 19 , and the sealing ring is embedded in the sealing ring groove of the receiving cup seat 4 .

[0049] In this implementation, preferably, the point light source 7 and the color sensor 10 are both fixed on the receiving cup 4 and arranged opposite to the straight pipe section 19 , and the point light source 7 is fixed on the receiving cup 4 by the cooperation of the first fixing member 8 and the second fixing member 9 .

[0050] In this implementation, preferably, the diameter of the point light source 7 is ≤ the diameter of the straight tube section 19 ≤ the diameter of the receiving cup 3 , so as to facilitate rapid sampling of the color sensor 10 .

[0051] In this implementation, preferably, the sealing ring groove includes a first sealing ring groove 11 and a second sealing ring groove 12 arranged vertically to facilitate quick removal of the receiving cup 3 , and the point light source 7 is located between the first sealing ring groove 11 and the second sealing ring groove 12 .

[0052] In this implementation, preferably, a drainage hole 13 is opened at the bottom of the straight pipe section 19 , and the drainage hole 13 is connected to the drainage channel 14 .

[0053] In the present implementation, preferably, a through hole is provided on the upper side wall of the portion of the receiving liquid inlet pipe 6 that protrudes into the receiving cup 3, which can effectively prevent back suction and reduce pipeline residue.

[0054] In this implementation, optionally, a stirring impeller is connected to the stirring rod 5, and the distance between the titration acid hole 15 and the center line of the stirring rod, and the distance between the receiving liquid inlet hole 16 and the center line of the stirring rod are respectively greater than the diameter of the stirring impeller. The flow rate of the liquid to be tested near the tip of the stirring impeller is the highest, which facilitates the rapid mixing of the titration acid and the receiving liquid.

[0055] In this implementation, an anti-diffusion device (such as a one-way valve) is installed at the outlet of the titrated acid inlet pipe, which is in a conductive state in the direction from the titrated acid to the receiving liquid to prevent mutual diffusion between the receiving liquid and the titrated acid, thereby improving the accuracy of the test results.

[0056] The working method of the high-efficiency receiving reaction device suitable for the Kjeldahl nitrogen analyzer includes the following process:

[0057] The stirring motor 1 is turned on, and the boric acid solution with the indicator added enters the receiving cup 3 through the boric acid inlet hole 18 and the boric acid inlet pipe;

[0058] The receiving liquid (ammonia solution) enters the receiving cup 3 through the receiving liquid inlet hole 16 and the receiving liquid inlet pipe 6 and reacts with the boric acid solution in the receiving cup 3. At this time, the color (or potential) of the solution in the receiving cup 3 changes.

[0059] The color sensor 10 detects the color change and feeds back to the sample pushing module. The sample pushing module pushes a certain amount of titrated acid into the receiving cup through the titrated acid hole 15 and the titrated acid inlet tube according to the set judgment logic. The titrated acid solution reacts with the solution in the receiving cup 3, and the corresponding color (or potential) changes. This titration process is repeated until the experiment is completed.

[0060] After the waste liquid is finished, it is discharged through the drain hole 13, and the receiving cup 3 can be directly removed from the receiving cup seat 4 for cleaning.

[0061] Embodiment 2:

[0062] This implementation provides a Kjeldahl nitrogen analyzer, including the high-efficiency receiving reaction device suitable for the Kjeldahl nitrogen analyzer described in Example 1 of the present invention.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An efficient receiving reaction device suitable for a Kjeldahl nitrogen analyzer, characterized in that: include: A receiving cup, a receiving cup cover, a stirring motor, and a receiving cup seat, wherein the stirring motor is fixed on the receiving cup cover, and a stirring rod of the stirring motor extends into the receiving cup, and the receiving cup is fixed in the receiving cup seat; The receiving cup cover is provided with a receiving liquid inlet hole and a titrating acid hole, and the receiving liquid inlet pipe passes through the receiving liquid inlet hole and extends into the interior of the receiving cup. The angle between the first connecting line between the center point of the receiving liquid inlet hole and the center point of the receiving cup cover and the second connecting line between the center point of the titrating acid hole and the center point of the receiving cup cover is ≤90°.

2. The high-efficiency receiving reaction device suitable for Kjeldahl nitrogen analyzer according to claim 1, characterized in that: The receiving cup cover is provided with a boric acid liquid inlet hole and an electrode fixing hole, and the electrode fixing hole is used for inserting a potential sensor.

3. The high-efficiency receiving reaction device suitable for Kjeldahl nitrogen analyzer according to claim 1, characterized in that: The angle between the first connecting line and the second connecting line is 45°.

4. The high-efficiency receiving reaction device suitable for Kjeldahl nitrogen analyzer according to claim 1, characterized in that: The stirring rod is connected with a stirring impeller, and the distance between the titration acid hole and the center line of the stirring rod, and the distance between the receiving liquid inlet hole and the center line of the stirring rod are respectively greater than the diameter of the stirring impeller.

5. The high-efficiency receiving reaction device suitable for Kjeldahl nitrogen analyzer according to claim 1, characterized in that: The bottom of the receiving cup is connected to a straight pipe section whose inner diameter is smaller than the body of the receiving cup, and a sealing ring is sleeved on the outer side of the straight pipe section, and the sealing ring is embedded in the sealing ring groove of the receiving cup seat; The point light source and the color sensor are both fixed on the receiving cup seat and arranged opposite to the straight pipe section, and the diameter of the point light source is ≤ the diameter of the straight pipe section ≤ the diameter of the receiving cup.

6. The high-efficiency receiving reaction device suitable for Kjeldahl nitrogen analyzer according to claim 5, characterized in that: The sealing ring groove comprises a first sealing ring groove and a second sealing ring groove arranged vertically, and the point light source is located between the first sealing ring groove and the second sealing ring groove; a drainage hole is provided at the bottom of the straight pipe section, and the drainage hole is connected to the drainage channel.

7. The high-efficiency receiving reaction device suitable for a Kjeldahl nitrogen analyzer according to any one of claims 1 to 6, characterized in that: A through hole is provided on the upper side wall of the portion of the receiving liquid inlet pipe that protrudes into the receiving cup; an anti-diffusion device is installed at the outlet of the titrating acid inlet pipe, which is in a conducting state in the direction from the titrating acid to the receiving liquid.

8. A working method of a high-efficiency receiving reaction device suitable for a Kjeldahl nitrogen analyzer according to any one of claims 1 to 7, using a potential sensor inserted into a receiving cup through a receiving cup cover for detection, comprising the following process: The stirring motor is turned on, and the boric acid solution with the indicator added enters the receiving cup through the boric acid inlet hole and the boric acid inlet tube; The receiving liquid enters the receiving cup through the receiving liquid inlet hole and the receiving liquid receiving tube and reacts with the boric acid solution in the receiving cup. At this time, the potential in the receiving cup changes. The potential sensor detects the potential change and feeds it back to the sample pushing module. The sample pushing module pushes a certain amount of titrating acid into the receiving cup through the titrating acid hole and the titrating acid inlet tube according to the set judgment logic. The titrating acid solution reacts with the solution in the receiving cup, and the corresponding potential changes. This titration process is repeated until the experiment is completed. After the process is finished, the waste liquid is discharged through the drain hole, and the receiving cup is directly removed from the receiving cup seat for cleaning.

9. A working method of a high-efficiency receiving reaction device suitable for a Kjeldahl nitrogen analyzer according to any one of claims 1 to 7, wherein a color sensor is used for detection. The process includes: The stirring motor is turned on, and the boric acid solution with the indicator added enters the receiving cup through the boric acid inlet hole and the boric acid inlet tube; The receiving liquid enters the receiving cup through the receiving liquid inlet hole and the receiving liquid receiving tube and reacts with the boric acid solution in the receiving cup. At this time, the color of the solution in the receiving cup changes. The color sensor detects the color change and feeds it back to the sample pushing module. The sample pushing module pushes a certain amount of titrating acid into the receiving cup through the titrating acid hole and the titrating acid inlet tube according to the set judgment logic. The titrating acid solution reacts with the solution in the receiving cup, and the corresponding color changes. This titration process is repeated until the end of the experiment. After the end, the waste liquid is discharged through the drain hole, and the receiving cup is directly removed from the receiving cup seat for cleaning.

10. A Kjeldahl nitrogen analyzer, characterized in that: The invention comprises a high-efficiency receiving reaction device suitable for a Kjeldahl nitrogen analyzer as described in any one of claims 1 to 7.

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