Precise sample liquid injection pump for Kjeldahl apparatus

Abstract

The utility model discloses a Kjeldahl apparatus sample liquid precise injection pump, which comprises a sample injection cylinder and a sample injection push-pull rod which are connected in a sliding manner, the sample injection cylinder is fixedly connected to the side part of a rack, and one end of the sample injection push-pull rod far away from the sample injection cylinder is fixedly connected with a sliding block; a screw rod arranged in the vertical direction is installed in the rack, sliding rods parallel to the screw rod are arranged on the left side and the right side of the screw rod respectively, the screw rod is in threaded connection with the sliding blocks, and the sliding rods are in sliding connection with the sliding blocks; a three-way electromagnetic valve is fixedly mounted at the bottom of the rack, the three-way electromagnetic valve is connected with one end of a communicating pipe, the outlet end of the liquid inlet pipe and the inlet end of the liquid outlet pipe, and the other end of the communicating pipe is connected with the bottom of the sample injection barrel. The precise injection pump for the sample liquid of the Kjeldahl apparatus is simple and reasonable in overall structure, can automatically suck and discharge the sample liquid, remarkably improves the automation degree, and can ensure the accuracy.

Description

Technical Field

[0001] The utility model relates to a precision injection pump for sample solution of a Kjeldahl nitrogen analyzer, belonging to the technical field of nitrogen content determination. Background Technique

[0002] The Kjeldahl nitrogen analyzer is a precision instrument specifically used for determining the total nitrogen content in samples, and is widely used for analyzing the nitrogen content or protein content of samples such as food, crops, seeds, soil, fertilizers, etc. Based on the Kjeldahl method, it conducts a digestion reaction on the sample in a strong acid environment to convert organic nitrogen into inorganic nitrogen, then adds alkali for distillation to convert inorganic nitrogen into ammonia nitrogen, and finally determines the total nitrogen content in the sample by titration.

[0003] At present, the Kjeldahl nitrogen analyzer mainly consists of parts such as a digestion furnace, a distiller, and a sample solution injection mechanism. Among them, the sample solution injection mechanism generally requires manual suction and discharge of liquid, resulting in great room for improvement in its automation degree and accuracy.

[0004] To sum up, the existing technology obviously has inconveniences and defects in actual use, so it is necessary to improve it. Content of the Utility Model

[0005] Aiming at the deficiencies in the background technique, the utility model provides a precision injection pump for sample solution of a Kjeldahl nitrogen analyzer. The overall structure is simple and reasonable, which can realize the automatic suction and discharge of the sample solution, significantly improve its automation degree, and ensure accuracy.

[0006] To solve the above technical problems, the utility model adopts the following technical solutions:

[0007] The precision injection pump for sample solution of a Kjeldahl nitrogen analyzer includes a sample injection cylinder and a sample injection push rod that are slidably connected. The sample injection cylinder is fixedly connected to the side of the frame, and one end of the sample injection push rod far from the sample injection cylinder is fixedly connected to a slider;

[0008] A screw rod arranged vertically is installed inside the frame. There are slide rods parallel to it on the left and right sides of the screw rod. The screw rod is threadedly connected to the slider, and the slide rod is slidably connected to the slider;

[0009] A three-way solenoid valve is fixedly installed at the bottom of the frame. The three-way solenoid valve is connected to one end of a connecting pipe, the outlet end of a liquid inlet pipe, and the inlet end of a liquid outlet pipe. The other end of the connecting pipe is connected to the bottom of the sample injection cylinder.

[0010] Further, two photoelectric switches arranged symmetrically up and down are fixedly installed on the upper side of the frame.

[0011] Further, a baffle for triggering the photoelectric switch is installed on the outer side of the slider, and the baffle moves synchronously with the slider.

[0012] Furthermore, the sample injection cylinder body is arranged vertically, and the sample injection cylinder body is fixedly connected to the side of the frame through two mounting seats arranged up and down.

[0013] Furthermore, the slider is arranged horizontally, the inner end of the slider extends into the frame, and the outer end of the slider is located outside the frame.

[0014] Furthermore, the sliding direction of the slider along the sliding rod is the same as the pushing and pulling direction of the sample injection push-pull rod.

[0015] Furthermore, the top end of the screw rod is rotationally connected to the top of the frame, and the bottom end of the screw rod is connected to the output shaft of the motor.

[0016] After the present utility model adopts the above technical solutions, compared with the prior art, it has the following advantages:

[0017] The motor pulls the sample injection push-pull rod through the slider, so that negative pressure is generated in the sample injection cylinder body, and the sample liquid enters the sample injection cylinder body through the liquid inlet pipe, the three-way solenoid valve and the connecting pipe, realizing the automatic suction of the sample liquid; the motor pushes the sample injection push-pull rod through the slider, and the sample liquid in the sample injection cylinder body is discharged after passing through the connecting pipe, the three-way solenoid valve and the liquid outlet pipe, realizing the automatic discharge of the sample liquid;

[0018] The baffle plate cooperates with the photoelectric switch to make the slider reach the extreme positions at both ends of the set displacement, thereby controlling the stroke of the sample injection push-pull rod and realizing the precise control of the injection volume of the sample liquid;

[0019] The overall structure of the present utility model is simple and reasonable, the cost is lower, and the overall size is smaller.

[0020] The present utility model will be described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0021] Figure 1 is a schematic structural diagram of the present utility model;

[0022] Figure 2 is a schematic structural diagram of the present utility model from another angle;

[0023] Figure 3 is Figure 2 the enlarged structural view of the M position in

[0024] In the figure, 1 - sample injection cylinder body, 2 - sample injection push-pull rod, 3 - slider, 4 - baffle plate, 5 - frame, 6 - photoelectric switch, 7 - sliding rod, 8 - motor, 9 - screw rod, 10 - three-way solenoid valve, 11 - connecting pipe, 12 - liquid inlet pipe, 13 - liquid outlet pipe, 14 - mounting seat. Detailed Embodiment

[0025] In order to have a clearer understanding of the technical features, objectives, and effects of the present utility model, the specific embodiments of the present utility model will now be described with reference to the accompanying drawings.

[0026] As Figures 1 - 3 Collectively shown, the present utility model provides a precision injection pump for Kjeldahl apparatus sample solution, including a sample injection cylinder 1 and a sample injection push rod 2 that are slidably connected. The sample injection cylinder 1 is fixedly connected to the side of the frame 5 through two mounting seats 14 arranged vertically, and the sample injection cylinder 1 is arranged in the vertical direction.

[0027] One end of the sample injection push rod 2 away from the sample injection cylinder 1 is fixedly connected to a horizontally arranged slider 3. The inner end of the slider 3 extends into the frame 5, and the outer end of the slider 3 is located outside the frame 5.

[0028] A vertically arranged screw rod 9 is installed inside the frame 5. On the left and right sides of the screw rod 9, there are slide rods 7 arranged parallel to it. The screw rod 9 and the slide rods 7 pass through the slider 3, and the screw rod 9 is threadedly connected to the slider 3, while the slide rods 7 are slidably connected to the slider 3. The direction in which the slider 3 slides along the slide rod 7 is the same as the direction in which the sample injection push rod 2 is pushed and pulled.

[0029] The top end of the screw rod 9 is rotatably connected to the top of the frame 5, and the bottom end of the screw rod 9 is connected to the output shaft of the motor 8. The motor 8 drives the screw rod 9 to rotate, thereby driving the slider 3 to slide along the slide rod 7.

[0030] A three-way solenoid valve 10 for controlling the flow direction of the sample liquid is fixedly installed at the bottom of the frame 5. The three-way solenoid valve 10 is connected to one end of the connecting pipe 11, the outlet end of the liquid inlet pipe 12, and the inlet end of the liquid outlet pipe 13.

[0031] The other end of the connecting pipe 11 is connected to the bottom of the sample injection cylinder 1.

[0032] The sample liquid can enter the sample injection cylinder 1 through the liquid inlet pipe 12, the three-way solenoid valve 10, and the connecting pipe 11, and the sample liquid in the sample injection cylinder 1 can be discharged after passing through the connecting pipe 11, the three-way solenoid valve 10, and the liquid outlet pipe 13.

[0033] Two photoelectric switches 6 arranged symmetrically up and down are fixedly installed on the upper side of the frame 5. A baffle 4 for triggering the photoelectric switch 6 is installed on the outer side of the slider 3, and the baffle 4 moves synchronously with the slider 3.

[0034] The cooperation between the baffle 4 and the photoelectric switch 6 enables the slider 3 to reach the extreme positions at both ends of the set displacement, thereby controlling the stroke of the sample injection push rod 2.

[0035] The specific working principle of the present utility model:

[0036] The motor 8 drives the screw rod 9 to rotate, thereby causing the slider 3 to slide along the slide rod 7. When the slider 3 moves away from the motor 8, the slider 3 pulls the sample injection push rod 2, generating a negative pressure in the sample injection cylinder 1. At the same time, the three-way solenoid valve 10 controls the communication between the liquid inlet pipe 12 and the connecting pipe 11, and the liquid outlet pipe 13 is closed and blocked. The sample liquid enters the sample injection cylinder 1 through the liquid inlet pipe 12, the three-way solenoid valve 10, and the connecting pipe 11;

[0037] When the three-way solenoid valve 10 controls the communication between the liquid outlet pipe 13 and the connecting pipe 11, the liquid inlet pipe 12 is closed and blocked. When the slider 3 moves towards the motor 8, the slider 3 pushes the sample injection push rod 2, causing the sample liquid in the sample injection cylinder 1 to be discharged after passing through the connecting pipe 11, the three-way solenoid valve 10, and the liquid outlet pipe 13;

[0038] When the baffle 4 moves synchronously with the slider 3 and touches the photoelectric switch 6, the slider 3 reaches the extreme positions at both ends of the set displacement, thereby controlling the stroke of the sample injection push rod 2 and achieving precise control of the injection volume of the sample liquid.

[0039] The above is an example of the best implementation mode of the present invention. The parts not described in detail are the common general knowledge of those skilled in the art. The protection scope of the present invention is subject to the content of the claims. Any equivalent transformation based on the technical inspiration of the present invention is also within the protection scope of the present invention.

Claims

1. Kjeldahl nitrogen analyzer sample liquid precision injection pump, characterized in that: It includes a sample injection cylinder body (1) and a sample injection push-pull rod (2) that are slidably connected. The sample injection cylinder body (1) is fixedly connected to the side of the frame (5), and one end of the sample injection push-pull rod (2) away from the sample injection cylinder body (1) is fixedly connected to the slider (3). A screw rod (9) arranged vertically is installed inside the frame (5). On the left and right sides of the screw rod (9), there are slide rods (7) arranged parallel to it. The screw rod (9) is threadedly connected to the slider (3), and the slide rod (7) is slidably connected to the slider (3). A three-way solenoid valve (10) is fixedly installed at the bottom of the frame (5). The three-way solenoid valve (10) is connected to one end of the connecting pipe (11), the outlet end of the liquid inlet pipe (12), and the inlet end of the liquid outlet pipe (13). The other end of the connecting pipe (11) is connected to the bottom of the sample injection cylinder body (1).

2. The Kjeldahl nitrogen analyzer sample solution precision injection pump according to claim 1, characterized in that: Two photoelectric switches (6) are symmetrically installed up and down on the upper side of the frame (5).

3. The Kjeldahl nitrogen analyzer sample liquid precision injection pump according to claim 2, characterized in that: A baffle (4) for triggering the photoelectric switch (6) is installed on the outer side of the slider (3), and the baffle (4) moves synchronously with the slider (3).

4. The Kjeldahl nitrogen analyzer sample liquid precision injection pump according to claim 1, characterized in that: The sample injection cylinder body (1) is arranged vertically, and the sample injection cylinder body (1) is fixedly connected to the side of the frame (5) through two mounting seats (14) arranged up and down.

5. The Kjeldahl nitrogen analyzer sample liquid precision injection pump according to claim 1, characterized in that: The slider (3) is arranged horizontally. The inner end of the slider (3) extends into the frame (5), and the outer end of the slider (3) is located outside the frame (5).

6. The Kjeldahl nitrogen analyzer sample liquid precision injection pump according to claim 1, characterized in that: The direction in which the slider (3) slides along the slide rod (7) is the same as the direction in which the sample injection push-pull rod (2) pushes and pulls.

7. The Kjeldahl nitrogen analyzer sample solution precision injection pump according to claim 1, characterized in that: The top end of the screw rod (9) is rotatably connected to the top of the frame (5), and the bottom end of the screw rod (9) is connected to the output shaft of the motor (8).

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