A reliable Kjeldahl nitrogen determination steam generation system, Kjeldahl nitrogen determination instrument and method

Abstract

The present invention provides a reliable Kjeldahl nitrogen determination steam generation system, a Kjeldahl nitrogen determination instrument and a method, comprising: a steam generator, an output pipeline of the steam generator is connected with a temperature sensor, an input port of the steam generator is connected with an output port of a pump group through a pipeline, and the input port of the pump group is used to communicate with a water source; the pump group at least comprises a first branch, a second branch and a third branch connected in parallel through the pipeline, and the first branch, the second branch and the third branch are selected according to the value of the temperature sensor, so that the value of the temperature sensor is stable within a set temperature range; the present invention realizes the reliable and stable operation of the steam generation system by connecting a plurality of pumps in parallel and working intermittently, effectively avoids the influence on the nitrogen determination experiment, and improves the test accuracy.

Description

Technical Field

[0001] The invention relates to the technical field of Kjeldahl nitrogen determination, and in particular to a reliable Kjeldahl nitrogen determination steam generation system, a Kjeldahl nitrogen determination instrument and a method. 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 nitrogen analyzer is an instrument that calculates the protein content by measuring the nitrogen content in the sample based on the principle that the nitrogen content in protein is constant; because the method of measuring and calculating the protein content is called the Kjeldahl method, it is called the Kjeldahl nitrogen analyzer. There are four processes in the Kjeldahl nitrogen determination experiment, namely digestion, distillation, absorption and titration. The organic matter in the sample is digested and converted into inorganic ammonium salts, and then the ammonia gas is released by distillation with alkali, and then absorbed by the acidic solution. The acidic absorption solution is titrated with a standard titration solution to restore the acidity, and the end point is determined by the color. Finally, the nitrogen content is calculated by the consumption volume and concentration of the titration solution.

[0004] The inventors have found that the existing distillation scheme has the following problems: (1) It can only produce saturated steam, which is easy to condense and is not conducive to distillation operation; (2) The steam generator supply pump needs to operate reliably for a long time. As the operating time of the existing pump increases, the reliability will decrease (such as the life and accuracy of the pump). This problem has not yet been solved and has become an industry problem; (3) There are few types of liquid pumps available on the market, and the flow adjustment range is narrow, which cannot be effectively used in the rectification system of the Kjeldahl nitrogen analyzer. Summary of the invention

[0005] In order to solve the shortcomings of the prior art, the present invention provides a reliable Kjeldahl nitrogen determination steam generation system, a Kjeldahl nitrogen determination instrument and a method. By connecting multiple liquid pumps in parallel and working intermittently, the reliable and stable operation of the steam generation system is achieved, the influence on the nitrogen determination experiment is effectively avoided, and the test accuracy is improved.

[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 reliable Kjeldahl nitrogen determination steam generation system.

[0008] A reliable Kjeldahl nitrogen determination steam generation system comprises: a steam generator, an output pipeline of the steam generator or a steam generator body is connected with a temperature sensor, an input port of the steam generator is connected with an output port of a pump group through a pipeline, and the input port of the pump group is used to communicate with a water source;

[0009] The pump group includes at least two branches connected in parallel through pipelines, and any one of the branches is selected for input according to the value of the temperature sensor so that the value of the temperature sensor is stabilized within a set temperature range.

[0010] As a further limitation of the first aspect of the present invention, the pump group includes a first branch, a second branch and a third branch, the first branch is connected to a first liquid pump and a first valve, the second branch is connected to a second liquid pump and a second valve, the third branch is connected to a third liquid pump and a third valve, the third branch is connected to a fourth valve in parallel, and a fifth valve is connected to the connecting pipeline between the steam generator and the pump group.

[0011] As a further limitation of the first aspect of the present invention, the digestion tube is located at the bottom of the splash-proof bottle, the splash-proof bottle and the internal space of the digestion tube are connected, the steam output pipeline of the steam generator is connected to the bottom of the digestion tube through the first pipeline, and the steam output pipeline of the steam generator is connected to the top of the splash-proof bottle through the second pipeline;

[0012] A sixth valve is connected to the first pipeline, a steam output pipeline of the steam generator is connected to the top of the splash-proof bottle through the first pipeline, and a seventh valve is connected to the second pipeline;

[0013] The top of the splash-proof bottle is connected to the condenser through a pipeline, a flow sensor is connected to the connecting pipeline between the splash-proof bottle and the condenser, the condenser is connected to the receiving cup through a pipeline, and an eighth valve is connected to the pipeline between the condenser and the receiving cup. The first branch, the second branch and the third branch are selected according to the value of the flow sensor so that the value of the flow sensor is stable within the set flow range.

[0014] In a second aspect, the present invention provides a reliable Kjeldahl nitrogen determination steam generation method.

[0015] A reliable Kjeldahl nitrogen determination steam generation method, using the reliable Kjeldahl nitrogen determination steam generation system according to the first aspect of the present invention, comprises the following process:

[0016] The first liquid pump, the second liquid pump and the third liquid pump are alternately switched on at a set working time;

[0017] After any branch is selected, the steam temperature at the steam generator outlet and the steam flow rate at the splash-proof bottle outlet are detected, and the selection control of other branches is performed according to the steam temperature and / or steam flow rate.

[0018] As a further limitation of the second aspect of the present invention, when the steam temperature at the steam generator outlet is higher than a set value and lasts for a set time, the currently operating branch is closed and any other branch in parallel is selected to be put into operation.

[0019] As a further limitation of the second aspect of the present invention, when the steam flow rate at the outlet of the splash-proof bottle is lower than a set value and lasts for a set time, the currently working branch is closed and any other branch in parallel is selected to be put into operation.

[0020] As a further limitation of the second aspect of the present invention, when the steam temperature at the steam generator outlet is higher than the set value and lasts for a set time, the opening of the fifth valve increases and the opening of the fourth valve decreases so that the steam temperature at the steam generator outlet is lower than the set value.

[0021] As a further limitation of the second aspect of the present invention, after the steam flow rate at the outlet of the splash-proof bottle is lower than the set value and lasts for a set time, the opening of the fifth valve increases and the opening of the fourth valve decreases, so that the steam flow rate at the outlet of the splash-proof bottle is higher than the set value.

[0022] As a further limitation of the second aspect of the present invention, when the liquid pump of a branch is selected N times in succession but the running time of each time is less than the set value, the selection and use of the branch is suspended, a maintenance alarm message is generated, and other branches are selected to be put into operation.

[0023] As a further limitation of the second aspect of the present invention, the set working time is greater than or equal to the time of a single experiment.

[0024] In a third aspect, the present invention provides a Kjeldahl nitrogen analyzer, comprising the reliable Kjeldahl nitrogen determination steam generation system described in the first aspect of the present invention.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The present invention provides a reliable Kjeldahl nitrogen determination steam generation system. By connecting multiple pumps in parallel and working intermittently, the reliable and stable operation of the steam generation system is achieved, the influence on the nitrogen determination experiment is effectively avoided, and the test accuracy is improved. After any branch is selected, the steam temperature at the outlet of the steam generator and the steam flow rate at the outlet of the splash-proof bottle are detected, and the selection control of other branches is performed according to the steam temperature and / or steam flow rate, so as to achieve stable steam output and improve the stability of the Kjeldahl nitrogen determination experiment.

[0027] 2. When the steam temperature at the outlet of the steam generator is higher than the set value and lasts for the set time, the opening of the fifth valve increases and the opening of the fourth valve decreases, so that the steam temperature at the outlet of the steam generator is lower than the set value; when the steam flow at the outlet of the splash-proof bottle is lower than the set value and lasts for the set time, the opening of the fifth valve increases and the opening of the fourth valve decreases, so that the steam flow at the outlet of the splash-proof bottle is higher than the set value. The overall control accuracy is further improved by the control of the fourth valve and the fifth valve. Under the premise that control can be achieved through the fourth valve and the fifth valve, there is no need to switch branches, thereby ensuring that the experiment can proceed normally.

[0028] 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

[0029] 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.

[0030] Figure 1 A schematic diagram of a reliable Kjeldahl nitrogen determination steam generation system provided by the present invention;

[0031] Among them, 1, the first liquid pump; 2, the second liquid pump; 3, the third liquid pump; 4, the fourth liquid pump; 5, the fifth liquid pump; 6, the sixth liquid pump; 7, the seventh liquid pump; 8, the first valve; 9, the second valve; 10, the third valve; 11, the fourth valve; 12, the fifth valve; 13, the sixth valve; 14, the seventh valve; 15, the eighth valve; 16, the ninth valve; 17, the tenth valve; 18, the first three-way valve; 19, the second three-way valve; 20, The third three-way valve; 21. The fourth three-way valve; 22. The fifth three-way valve; 23. The sixth three-way valve; 24. The temperature sensor; 25. The flow sensor; 26. The splash-proof bottle; 27. The digestion tube; 28. The condenser; 29. ​​The receiving cup; 30. The first one-way valve; 31. The second one-way valve; 32. The third one-way valve; 33. The fourth one-way valve; 34. The fifth one-way valve; 35. The pressure relief valve; 35. The eleventh valve; 36. The twelfth valve; 37. The steam generator. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0033] 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.

[0034] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0035] Embodiment 1:

[0036] In this implementation, a reliable Kjeldahl nitrogen determination steam generation system is proposed, such as Figure 1 As shown, it includes: a steam generator 37, a temperature sensor 24 is connected to the output pipeline of the steam generator 37 or the body of the steam generator 37, the input port of the steam generator 37 is connected to the output port of the pump group through a pipeline, and the input port of the pump group is used to communicate with a water source;

[0037] The pump group at least includes a first branch, a second branch and a third branch connected in parallel through pipelines, the first branch is connected with a first liquid pump 1 and a first valve 8, the second branch is connected with a second liquid pump 2 and a second valve 9, the third branch is connected with a third liquid pump 3 and a third valve 10, the third branch is connected with a fourth valve 11 in parallel, and a fifth valve 12 is connected to the connecting pipeline between the steam generator 37 and the pump group. The first branch, the second branch and the third branch are selected according to the value of the temperature sensor 24 so that the value of the temperature sensor 24 is stable within the set temperature range.

[0038] In this implementation, the digestion tube 27 is located at the bottom of the splash-proof bottle 26, the splash-proof bottle 26 and the internal space of the digestion tube 27 are connected, the steam output pipeline of the steam generator 37 is connected to the bottom of the digestion tube 27 through the first pipeline, and the steam output pipeline of the steam generator 37 is connected to the top of the splash-proof bottle 26 through the second pipeline;

[0039] The first pipeline is connected to a sixth valve 13, the steam output pipeline of the steam generator 37 is connected to the top of the splash-proof bottle 26 through the first pipeline, and the second pipeline is connected to a seventh valve 14;

[0040] The top of the splash-proof bottle 26 is connected to the condenser 28 through a pipeline, a flow sensor 25 is connected to the connecting pipeline between the splash-proof bottle 26 and the condenser 28, the condenser 28 is connected to the receiving cup 29 through a pipeline, and an eighth valve 15 is connected to the pipeline between the condenser 28 and the receiving cup 29.

[0041] In this implementation, preferably, the fourth three-way valve 21 and the fifth three-way valve 22 are connected in sequence on the pipeline between the sixth valve 13 and the digestive tract 27, the first port of the fourth three-way valve 21 is connected to the fifth one-way valve 34, the first port of the fifth three-way valve 22 is connected to the eleventh valve 35, and the eleventh valve 35 is connected to the first port of the sixth three-way valve 23 through a pipeline.

[0042] In this implementation, preferably, the first port of the first three-way valve 18 is connected to the water source, the second port of the first three-way valve 18 is connected to the input port of the pump group, the third port of the first three-way valve 18 is connected to the fourth liquid pump 4, the fourth liquid pump 4 is connected to the first port of the second three-way valve 19, the second port of the second three-way valve 19 is connected to the tenth valve 17, and the tenth valve 17 is connected to the top of the splash-proof bottle 26 through a pipeline.

[0043] In this implementation, preferably, the fifth liquid pump 5 is connected to the second one-way valve 31, the fifth liquid pump 5 is used to input acid liquid such as boric acid, the second one-way valve 31 is connected to the first port of the third three-way valve 20, the second port of the third three-way valve 20 is connected to the ninth valve 16, the ninth valve 16 is connected to the third port of the second three-way valve 19, the third port of the third three-way valve 20 is connected to the receiving cup 29, and the receiving cup 29 is connected to the fourth one-way valve 33.

[0044] In this implementation, preferably, the seventh liquid pump 7 is connected to the first one-way valve 30 through a pipeline, the first one-way valve 30 is connected to the top of the splash-proof bottle 26 through a pipeline, and the seventh liquid pump 7 is used to transport alkaline solution (such as sodium hydroxide solution).

[0045] In this implementation, preferably, the bottom of the receiving cup 29 is connected to the twelfth valve 36, the twelfth valve 36 is connected to the sixth liquid pump 6, the sixth liquid pump 6 is connected to the third one-way valve 32, the third one-way valve 32 is connected to the third port of the sixth three-way valve 23, and the second port of the sixth three-way valve 23 is used for waste discharge.

[0046] In this implementation, preferably, the junction of the first pipeline, the output pipeline of the steam generator 37 and the second pipeline is connected to the pressure relief valve 35 through the pipeline.

[0047] In this implementation, a working method of the above-mentioned reliable Kjeldahl nitrogen determination steam generation system is provided, including:

[0048] The first liquid pump 1, the second liquid pump 2 and the third liquid pump 3 are alternately switched on at a set working time;

[0049] After any branch is selected (only one branch is selected each time), the steam temperature at the outlet of the steam generator 37 and the steam flow rate at the outlet of the splash-proof bottle 26 are detected, and the selection control of other branches is performed according to the steam temperature and / or steam flow rate.

[0050] In this implementation, preferably, when the steam temperature at the outlet of the steam generator 37 is higher than the set value and lasts for a set time, the currently working branch is closed and any other branch in parallel is selected to be put into operation.

[0051] In this implementation, preferably, after the steam flow rate at the outlet of the splash-proof bottle 26 is lower than the set value and lasts for a set time, the currently working branch is closed and any other branch in parallel is selected to be put into operation.

[0052] In this implementation, preferably, when the steam temperature at the outlet of the steam generator 37 is higher than the set value and lasts for a set time, the opening of the fifth valve 12 increases and the opening of the fourth valve 11 decreases, so that the steam temperature at the outlet of the steam generator 37 is lower than the set value.

[0053] In this implementation, preferably, after the steam flow rate at the outlet of the splash-proof bottle 26 is lower than the set value and lasts for a set time, the opening of the fifth valve 12 increases and the opening of the fourth valve 11 decreases, so that the steam flow rate at the outlet of the splash-proof bottle 26 is higher than the set value.

[0054] In this implementation, preferably, when the liquid pump of a branch is selected N times in succession but the running time of each time is less than the set value, the selection and use of the branch is suspended, a maintenance alarm message is generated, and other branches are selected to be put into operation.

[0055] In this implementation, preferably, the set working time is greater than or equal to the time of a single experiment.

[0056] It can be understood that when the above single branch gating control method cannot achieve temperature or flow control, two branches or three branches can be selected to achieve temperature or flow control;

[0057] It can be understood that the three branches here are only preferred designs, and there may be only two branches, or there may be more branches, which will not be described in detail here.

[0058] Embodiment 2:

[0059] This implementation provides a Kjeldahl nitrogen analyzer, including the reliable Kjeldahl nitrogen determination steam generation system described in Example 1 of the present invention.

[0060] 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. A reliable Kjeldahl nitrogen determination steam generation system, characterized in that: include: A steam generator, wherein a temperature sensor is connected to an output pipeline of the steam generator or to a body of the steam generator, an input port of the steam generator is connected to an output port of a pump group through a pipeline, and an input port of the pump group is used to communicate with a water source; The pump group includes at least two branches connected in parallel through pipelines, and any one of the branches is selected for input according to the value of the temperature sensor so that the value of the temperature sensor is stabilized within a set temperature range; The pump group includes a first branch, a second branch and a third branch, the first branch is connected to a first liquid pump and a first valve, the second branch is connected to a second liquid pump and a second valve, the third branch is connected to a third liquid pump and a third valve, the third branch is connected in parallel with a fourth valve, and the connecting pipeline between the steam generator and the pump group is connected to a fifth valve; The digestion tube is located at the bottom of the splash-proof bottle, the splash-proof bottle and the internal space of the digestion tube are connected, the steam output pipeline of the steam generator is connected to the bottom of the digestion tube through the first pipeline, and the steam output pipeline of the steam generator is connected to the top of the splash-proof bottle through the second pipeline; A sixth valve is connected to the first pipeline, a steam output pipeline of the steam generator is connected to the top of the splash-proof bottle through the first pipeline, and a seventh valve is connected to the second pipeline; The top of the splash-proof bottle is connected to the condenser through a pipeline, a flow sensor is connected to the connecting pipeline between the splash-proof bottle and the condenser, the condenser is connected to the receiving cup through a pipeline, an eighth valve is connected to the pipeline between the condenser and the receiving cup, and the first branch, the second branch and the third branch are selected according to the value of the flow sensor so that the value of the flow sensor is stable within the set flow range; When the steam temperature at the steam generator outlet is higher than the set value and lasts for the set time, the current working branch is closed and any other branch in parallel is selected to be put into operation; When the steam flow rate at the outlet of the splash-proof bottle is lower than the set value and lasts for the set time, the current working branch is closed and any other branch in parallel is selected to be put into operation; When the steam temperature at the steam generator outlet is higher than the set value and lasts for a set time, the opening of the fifth valve increases and the opening of the fourth valve decreases, so that the steam temperature at the steam generator outlet is lower than the set value; After the steam flow rate at the outlet of the splash-proof bottle is lower than the set value and lasts for a set time, the opening of the fifth valve increases and the opening of the fourth valve decreases, so that the steam flow rate at the outlet of the splash-proof bottle is higher than the set value.

2. A reliable Kjeldahl nitrogen determination steam generation method, characterized in that: Using the reliable Kjeldahl nitrogen steam generation system according to claim 1, The process includes: The first liquid pump, the second liquid pump and the third liquid pump are alternately switched on at a set working time; After any branch is selected, the steam temperature at the steam generator outlet and the steam flow rate at the splash-proof bottle outlet are detected, and the selection control of other branches is performed according to the steam temperature and / or steam flow rate.

3. The reliable Kjeldahl nitrogen determination steam generation method according to claim 2, characterized in that: When the liquid pump of a branch is selected N times in succession but the running time of each time is less than the set value, the selection and use of the branch is suspended, a maintenance alarm message is generated, and other branches are selected to be put into operation.

4. The reliable Kjeldahl nitrogen determination steam generation method according to claim 2, characterized in that: The set working time is greater than or equal to the time of a single experiment.

5. A Kjeldahl nitrogen analyzer, characterized in that: The invention comprises the reliable Kjeldahl nitrogen determination steam generation system as claimed in claim 1.

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