Hydroxyethyl starch closed etherification precise control system

Abstract

The utility model relates to a hydroxyethyl starch closed etherification precise control system, and belongs to the technical field of hydroxyethyl starch processing. The system comprises a nitrogen storage tank, an ethylene oxide storage tank and an etherification tank, one end of the first connecting pipeline is communicated with the nitrogen storage tank, the other end of the first connecting pipeline is communicated with the etherification tank, and a first pneumatic valve, a pressure gauge, a branch pipeline interface and a temperature and pressure regulating valve are sequentially arranged from the nitrogen storage tank to the etherification tank; one end of the second connecting pipeline is communicated with the ethylene oxide storage tank, and the other end of the second connecting pipeline is communicated with the branch pipeline interface; an automatic flow regulating valve is arranged on the second connecting pipeline close to the interface of the branch pipeline; the PLC is electrically connected with the first pneumatic valve, the pressure gauge, the temperature and pressure regulating valve, the metering flowmeter and the automatic flow regulating valve. According to the utility model, through the closed automatic gas transmission system, the accurate metering and safe use of ethylene oxide are realized, and the safety risk in the production process is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of the processing of raw material drug hydroxyethyl starch, and particularly relates to a closed etherification precise control system for hydroxyethyl starch. Background Art

[0002] In the current era of rapid development of information and technology, a large number of mechanized and automated products are spread all over various fields of production and life. The application of mechanical automation products saves a large amount of manpower and material resources and improves work efficiency, but at the same time, it also brings inevitable errors and risks.

[0003] In the etherification process of hydroxyethyl starch 130 / 0.4, ethylene oxide needs to be used for the etherification reaction. Ethylene oxide is a very active substance with the characteristics of being flammable, explosive and toxic. Ethylene oxide vapor can form an explosive mixture with air over a wide range. It has the danger of combustion and explosion when encountering heat sources and open flames. If exposed to high heat, it can undergo violent decomposition, thus causing container rupture or explosion accidents. Due to the toxicity and flammable and explosive characteristics of ethylene oxide, in the etherification process of hydroxyethyl starch 130 / 0.4, the safety of ethylene oxide metering and transportation is a major problem. At present, the weighing of ethylene oxide generally adopts the method of using a platform scale and is transported through a hose. The valve needs to be manually switched, and on-site manual monitoring is required. This method is not only inconvenient to operate but also has relatively high safety risks. Summary of the Invention

[0004] The purpose of the utility model is to provide a closed etherification precise control system for hydroxyethyl starch to solve the defects existing in the use of ethylene oxide in the etherification process in the prior art, thereby reducing safety risks. The technical solution adopted by the utility model is as follows:

[0005] A closed etherification precise control system for hydroxyethyl starch includes a nitrogen storage tank, an ethylene oxide storage tank and an etherification tank; one end of a first connecting pipeline is communicated with the nitrogen storage tank, and the other end of the first connecting pipeline is communicated with the etherification tank; on the first connecting pipeline, a first pneumatic valve, a pressure gauge, a branch pipeline interface and a temperature and pressure regulating valve are sequentially arranged along the direction from the nitrogen storage tank to the etherification tank; one end of a second connecting pipeline is communicated with the ethylene oxide storage tank, and the other end of the second connecting pipeline is communicated with the branch pipeline interface; a metering flowmeter is arranged in the middle of the second connecting pipeline; a flow automatic regulating valve is arranged on the second connecting pipeline near the branch pipeline interface; a PLC controller is respectively connected with the first pneumatic valve, the pressure gauge, the temperature and pressure regulating valve, the metering flowmeter and the flow automatic regulating valve.

[0006] Preferably, an ethylene oxide detection probe is arranged beside the ethylene oxide storage tank; the ethylene oxide detection probe is electrically connected with the PLC controller.

[0007] Preferably, an alarm is provided on the outer periphery of the first connecting pipeline between the temperature and pressure regulating valve and the etherification tank; the alarm is electrically connected to the PLC controller.

[0008] Preferably, an automatic sprinkler system is installed above the ethylene oxide storage tank. The water outlet end of the automatic sprinkler system is located directly above the ethylene oxide storage tank. The water inlet end of the automatic sprinkler system is connected to a water source. A second pneumatic valve is provided on the pipeline between the water inlet end and the water outlet end of the automatic sprinkler system, and the second pneumatic valve is electrically connected to the PLC controller.

[0009] Preferably, the PLC controller is electrically connected to an upper computer with data viewing, storage, and operation functions.

[0010] Preferably, it further includes a sealed storage cabinet. The ethylene oxide detection probe, the ethylene oxide storage tank, and the automatic sprinkler system are located in the sealed storage cabinet, and a waste water bucket is provided at the bottom of the sealed storage cabinet.

[0011] Advantages of the present utility model:

[0012] During the etherification process of hydroxyethyl starch, the present utility model realizes the tightness and continuity of ethylene oxide gas transportation, realizes accurate metering of ethylene oxide, safe use, and anti-leakage transportation, facilitates the control of the hydroxyethyl starch etherification process, and at the same time reduces the safety risks in the production process. The system operates in a fully enclosed manner, avoiding the leakage of ethylene oxide gas and greatly reducing safety risks; this set of system is reasonably designed, simple in structure, and safe and convenient to operate. Description of the Drawings

[0013] The drawings are used to provide further understanding of the present utility model and constitute a part of the specification. They are used together with the embodiments of the present utility model to explain the present utility model, but do not constitute a limitation to the present utility model. In the drawings:

[0014] Figure 1 is a schematic structural diagram of the closed etherification precision control system of hydroxyethyl starch according to Embodiment 1 of the present utility model;

[0015] Among them, 1. PLC controller, 2. Flow automatic regulating valve, 3. Metering flowmeter, 4. Ethylene oxide detection probe, 5. Alarm, 6. Etherification tank, 7. Temperature and pressure regulating valve, 8. Pressure gauge, 9. First connecting pipeline, 10. Second connecting pipeline, 11. Automatic sprinkler system, 12. First pneumatic valve, 13. Second pneumatic valve, 14. Ethylene oxide storage tank, 15. Nitrogen storage tank, 16. Branch pipeline interface. Detailed Embodiments

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are some but not all of the embodiments of the present utility model. Example 1

[0017] Figure 1 There is provided a precise control system for the closed etherification of hydroxyethyl starch, which includes a nitrogen storage tank 15, an ethylene oxide storage tank 14, and an etherification tank 6 that are interconnected through connecting pipelines; the nitrogen storage tank 15 on the left is connected to the etherification tank 6 on the right through a first connecting pipeline 9. A first pneumatic valve 12, a pressure gauge 8, a branch pipeline interface 16, and a temperature and pressure regulating valve 7 are sequentially arranged on the first connecting pipeline 9 from left to right. An alarm 5 is fixedly installed on the outer peripheral surface of the first connecting pipeline 9 near one end of the etherification tank 6; one end of a second connecting pipeline 10 is connected to the top of the ethylene oxide storage tank 14, and the other end of the second connecting pipeline 10 is connected to the first connecting pipeline 9 through the branch pipeline interface 16, so that the middle ethylene oxide storage tank 14 is connected to the etherification tank 6; a metering flowmeter 3 is arranged in the middle of the second connecting pipeline 10, and a flow automatic regulating valve 2 is arranged on the second connecting pipeline 10 near the branch pipeline interface 16.

[0018] The precise control system for the closed etherification of hydroxyethyl starch further includes an ethylene oxide detection probe 4, which can be installed near the ethylene oxide storage tank 14 through a bracket or directly installed on the upper surface of the ethylene oxide storage tank 14.

[0019] An automatic sprinkler system 11 is installed above the ethylene oxide storage tank 14. The water outlet end of the automatic sprinkler system 11 is located directly above the ethylene oxide storage tank 14. The water inlet end of the automatic sprinkler system 11 is connected to a water source, and a second pneumatic valve 13 is arranged on the pipeline between the water inlet end and the water outlet end of the automatic sprinkler system 11.

[0020] The precise control system for the closed etherification of hydroxyethyl starch further includes a PLC controller 1. The PLC controller 1 is respectively connected to the second pneumatic valve 13, the first pneumatic valve 12, the flow automatic regulating valve 2, the pressure gauge 8, the metering flowmeter 3, the ethylene oxide detection probe 4, the temperature and pressure regulating valve 7, and the alarm 5.

[0021] The PLC controller 1 can also be electrically connected to a host computer. The data received and sent by the PLC controller 1 can be viewed and stored through the host computer.

[0022] The PLC controller can adopt a Siemens S7-400 controller. The first pneumatic valve 12 and the second pneumatic valve 13 can adopt Festo VL / O-3-1 / 8 pneumatic valves. The temperature and pressure regulating valve 7 can adopt a VVF53 automatic regulating valve. The ethylene oxide detection probe 4 can adopt a DN-T1000 / F point-type gas detector.

[0023] For the precise control system for the closed etherification of hydroxyethyl starch in the embodiment of the present utility model, its working process is as follows:

[0024] When the etherification process of hydroxyethyl starch begins, the PLC controller 1 controls the closing of the first pneumatic valve 12, so that the nitrogen storage tank 15 and the etherification tank 6 are not connected. The PLC controller 1 controls the start of the automatic flow regulating valve 2, and introduces ethylene oxide of a set flow value into the etherification tank 6. When the metering flowmeter 3 detects that the ethylene oxide flow value reaches the set value, the PLC controller 1 controls the closing of the automatic flow regulating valve 2; at the same time, the PLC controller 1 controls the start of the first pneumatic valve 12, and sets the working time of the first pneumatic valve 12 to five minutes. During the working period of the first pneumatic valve 12, the ethylene oxide remaining in the pipeline is blown into the etherification tank 6. When the working time reaches the set time, the PLC controller 1 controls the closing of the first pneumatic valve 12, thereby accurately controlling the use of ethylene oxide. In addition, this step can also be used to empty the residual ethylene oxide in the pipeline before pipeline repair and maintenance to reduce the risk of ethylene oxide leakage. Since nitrogen is an inert gas and does not react with ethylene oxide, the use of nitrogen purging can control the amount of ethylene oxide used more accurately and reduce deviations without affecting the etherification reaction in normal production.

[0025] When hydroxyethyl starch passes through ethylene oxide, the etherification temperature requirement is relatively high, and the temperature is specified not to exceed plus or minus 1°C, otherwise the etherification quality will be affected. The temperature and pressure regulating valve 7 uses existing products, such as Siemens VVF53 series automatic regulating valve, which has built-in temperature and pressure sensors and can be used as a temperature and pressure value monitoring device. When the value exceeds the limit value at the current step pressure, the flow size and on-off of the temperature and pressure regulating valve 7 and the flow automatic regulating valve 2 are adjusted by the PLC controller 1, thereby reducing the safety risk of this set of equipment and improving the quality of the etherification product.

[0026] The ethylene oxide detection probe 4 sends the concentration value of ethylene oxide in the environment to the PLC controller 1 in real time. When it is detected that the concentration of ethylene oxide in the production environment exceeds the set value, the PLC controller 1 controls the alarm 5 to start the alarm, and the PLC controller 1 controls the closing of the automatic flow regulating valve 2; at the same time, the PLC controller 1 controls the start of the second pneumatic valve 13, and the automatic shower system 11 sprays mist water to treat the ethylene oxide leaked around the ethylene oxide storage tank 14. Since ethylene oxide is easy to combine with water, the spray device can make the water mist mix with ethylene oxide to form tiny droplets and drip, which can quickly reduce the concentration of ethylene oxide in the air and reduce the risk factor. When the ethylene oxide detection probe 4 detects that the ethylene oxide concentration is lower than the set value, the PLC controller 1 controls this system to automatically shut down. When the outside temperature is high during the production process, the staff can also input instructions through the PLC controller 1 host computer to open the automatic shower system 11 to cool the ethylene oxide storage tank 14 to reduce the risk of using ethylene oxide. Embodiment 2

[0027] Embodiment 2 further optimizes the technical solution on the basis of Embodiment 1 by adding an airtight storage cabinet. The ethylene oxide detection probe 4, the ethylene oxide storage tank 14, and the automatic sprinkler system 11 are installed in the airtight storage cabinet, and a wastewater bucket is arranged at the bottom of the airtight storage cabinet.

[0028] In Embodiment 2 after further improvement, the detection of ethylene oxide leakage can be made more accurate, and the water sprayed by the automatic sprinkler system 11 can be automatically collected in the wastewater bucket, avoiding wastewater overflow.

[0029] In the embodiments of the present utility model, the technical features not described in detail are all prior arts or conventional technical means and will not be elaborated herein.

[0030] Finally, it should be noted that the above embodiments are only specific implementation manners of the present utility model, used to illustrate the technical solutions of the present utility model, rather than limiting it. The protection scope of the present utility model is not limited thereto. Those skilled in the art should understand that any person skilled in the art within the technical scope disclosed by the present utility model can modify the technical solutions recorded in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present utility model, and should all be covered within the protection scope of the present utility model.

Claims

1. A closed etherification precise control system for hydroxyethyl starch, characterized in that: It includes a nitrogen storage tank (15), an ethylene oxide storage tank (14) and an etherification tank (6); one end of a first connecting pipeline (9) is communicated with the nitrogen storage tank (15), and the other end of the first connecting pipeline (9) is communicated with the etherification tank (6); on the first connecting pipeline (9), a first pneumatic valve (12), a pressure gauge (8), a branch pipeline interface (16) and a temperature and pressure regulating valve (7) are sequentially arranged along the direction from the nitrogen storage tank (15) to the etherification tank (6); one end of a second connecting pipeline (10) is communicated with the ethylene oxide storage tank (14), and the other end of the second connecting pipeline (10) is communicated with the branch pipeline interface (16); a metering flowmeter (3) is arranged in the middle of the second connecting pipeline (10); a flow automatic regulating valve (2) is arranged on the second connecting pipeline (10) near the branch pipeline interface (16); a PLC controller (1) is respectively connected with the first pneumatic valve (12), the pressure gauge (8), the temperature and pressure regulating valve (7), the metering flowmeter (3) and the flow automatic regulating valve (2).

2. The hydroxyethyl starch closed etherification precision control system according to claim 1, characterized in that: An ethylene oxide detection probe (4) is arranged beside the ethylene oxide storage tank (14); the ethylene oxide detection probe (4) is electrically connected with the PLC controller (1).

3. The hydroxyethyl starch closed etherification precise control system according to claim 2, characterized in that: An alarm (5) is arranged on the outer periphery of the first connecting pipeline (9) between the temperature and pressure regulating valve (7) and the etherification tank (6); the alarm (5) is electrically connected with the PLC controller (1).

4. The hydroxyethyl starch closed etherification precise control system according to claim 2, wherein: An automatic sprinkler system (11) is installed above the ethylene oxide storage tank (14), the water outlet end of the automatic sprinkler system (11) is located directly above the ethylene oxide storage tank (14), the water inlet end of the automatic sprinkler system (11) is communicated with a water source, a second pneumatic valve (13) is arranged on the pipeline between the water inlet end and the water outlet end of the automatic sprinkler system (11), and the second pneumatic valve (13) is electrically connected with the PLC controller (1).

5. The hydroxyethyl starch closed etherification precision control system according to claim 1, characterized in that: The PLC controller (1) is electrically connected with an upper computer with data viewing, storing and operating functions.

6. The hydroxyethyl starch closed etherification precise control system according to claim 4, characterized in that: It further includes an airtight storage cabinet, the ethylene oxide detection probe (4), the ethylene oxide storage tank (14) and the automatic sprinkler system (11) are located in the airtight storage cabinet, and a waste water bucket is arranged at the bottom of the airtight storage cabinet.

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