A treatment device for recovering dichloromethane in the production of acephate

Abstract

This utility model relates to the field of acephate production technology and discloses a treatment device for recovering dichloromethane in acephate production, including a storage tank unit, a treatment unit, and a separation unit. The storage tank unit is used to store recovered and purified dichloromethane and to provide liquid alkali and process water to the treatment unit. This utility model has the following advantages and effects: the recovered dichloromethane from acephate production is mixed with a certain concentration of alkali solution in an alkali washing kettle. The mixed material is then passed through a retention kettle, stirred and held, and then passed through an oil-water separator to effectively separate wastewater and alkali-washed dichloromethane. The alkali-washed wastewater can be directly used as a biochemical carbon source for sewage treatment plants. The alkali-washed dichloromethane is then passed through a water washing kettle and an oil-water separator to obtain dichloromethane with a purity greater than 99%. The washing water can be directly used as alkali solution dilution water.

Description

Technical Field

[0001] This utility model relates to the field of acephate production technology, and in particular to a treatment device for recovering dichloromethane in the production of acephate. Background Technology

[0002] Acephate is a widely used organophosphorus insecticide both domestically and internationally, and it is also one of the pesticides with the largest production tonnage in my country. Currently, the post-processing technology of acephate technical in China involves neutralization, extraction, distillation, crystallization, filtration, and drying. During the refining and separation process of acephate, nearly 10 tons of dichloromethane solvent are used to produce every ton of acephate technical. The recovered dichloromethane contains sulfur-containing organic matter and acetate esters, which affect the quality of acephate technical when reused in the production process, and also have a certain impact on the production site and waste disposal.

[0003] In the existing technology, the main method for recovering and purifying dichloromethane in the production of acephate is through distillation. Although distillation can purify dichloromethane, the recovery rate is significantly reduced due to the low boiling point of dichloromethane. Moreover, high-boiling-point impurities will exist as residual liquid, generating a certain amount of waste liquid. Utility Model Content

[0004] The purpose of this invention is to provide a processing device for recovering dichloromethane in the production of acephate, so as to solve the above-mentioned problems.

[0005] The above-mentioned technical objective of this utility model is achieved through the following technical solution: a treatment device for recovering dichloromethane in the production of acephate, comprising a storage tank unit, a treatment unit and a separation unit;

[0006] The storage tank unit is used to store recovered and purified dichloromethane, and to supply liquid alkali and process water to the treatment unit;

[0007] The processing unit is connected to the storage tank unit. The processing unit is used for alkaline washing treatment to recover dichloromethane and sends the treated material to the separation unit.

[0008] The separation unit is connected to the treatment unit and the storage tank unit. The separation unit is the place where the aqueous phase and organic phase of the qualified alkaline washing material are separated. The separated alkaline washing wastewater is sent to the sewage treatment plant as a carbon source through the separation unit. The aqueous phase and organic phase of the material washed by the treatment unit are separated through the separation unit and sent to the storage tank unit for storage.

[0009] A further feature of this invention is that the storage tank unit includes a dichloromethane recovery storage tank, a liquid alkali storage tank, and a washing water storage tank connected to the processing unit.

[0010] By adopting the above technical solution, the stored recovered dichloromethane and liquid alkali are used for alkaline washing treatment of dichloromethane.

[0011] A further feature of this invention is that the processing unit includes an alkaline washing kettle, into which recovered dichloromethane from a dichloromethane recovery tank, liquid alkali from a liquid alkali storage tank, and washing water from a washing water storage tank are fed.

[0012] By adopting the above technical solution, when the liquid level in the alkaline washing tank reaches the set value, the alkaline washing tank continues to discharge materials.

[0013] A further feature of this invention is that the processing unit also includes a retention vessel, into which the material in the alkaline washing vessel is fed for stirring and retention. Regulating valves are installed at both the inlet and outlet of the alkaline washing vessel, and a detector for detecting dichloromethane content is installed on the outlet regulating valve.

[0014] By employing the above technical solution, the content of acidic impurities in liquid alkali and dichloromethane was detected.

[0015] A further feature of this invention is that the processing unit includes an oil-water separator a, and the material in the retention vessel is fed into the oil-water separator a for phase separation.

[0016] By adopting the above technical solution, the liquid level in the residence tank is set to a predetermined value.

[0017] A further feature of this invention is that the processing unit also includes a washing tank, the wastewater separated in the oil-water separator a is discharged into a sewage treatment plant as a carbon source, and the separated organic phase is discharged into the washing tank.

[0018] By adopting the above technical solution, the side outlet of oil-water separator a is connected to the sewage conveying system.

[0019] A further feature of this invention is that the storage tank unit further includes a process water storage tank, and the separation unit further includes an oil-water separator b connected to the washing kettle, wherein the process water storage tank is connected to the washing kettle.

[0020] By adopting the above technical solution, it is convenient to provide process water to the washing tank.

[0021] A further feature of this invention is that the storage tank unit also includes purified dichloromethane connected to the oil-water separator b, and the oil-water separator b is connected to the washing water storage tank.

[0022] A further feature of this invention is that the storage tank unit, the processing unit, and the separation unit are connected by pipelines, and a delivery pump is installed on the pipelines.

[0023] The beneficial effects of this utility model are:

[0024] Under normal temperature and pressure conditions, the recovered dichloromethane from the production of acephate is mixed with a certain concentration of alkaline solution in an alkaline washing kettle. The mixed material is then passed through a holding kettle, stirred and held, and then passed through an oil-water separator to effectively separate the wastewater and the alkaline-washed dichloromethane. The wastewater after alkaline washing can be directly used as a biochemical carbon source for sewage treatment plants. The alkaline-washed dichloromethane is then passed through a water washing kettle and an oil-water separator to obtain dichloromethane with a content greater than 99%. The washing water can be directly used as dilution water for alkaline solution.

[0025] In addition, this device can operate safely, stably, and continuously, solving the problem of low dichloromethane content in the production of acephate. Furthermore, the generated aqueous phase can be directly used as a biochemical carbon source for wastewater treatment plants, effectively achieving both environmental and economic benefits. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A schematic diagram of a treatment device for recovering dichloromethane in the production of acephate provided in this embodiment of the present invention;

[0028] In the diagram, 11 is a dichloromethane recovery storage tank; 12 is a liquid alkali storage tank; 13 is a process water storage tank; 14 is a washing water storage tank; 15 is a purified dichloromethane storage tank; 21 is an alkali washing kettle; 22 is a retention kettle; 23 is a washing kettle; 31 is an oil-water separator a; 32 is an oil-water separator b; and 5 is a transfer pump. Detailed Implementation

[0029] The technical solution of this utility model will now be clearly and completely described with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0030] This utility model embodiment specifically provides a treatment device for recovering dichloromethane in the production of acephate. Please refer to... Figure 1 It includes storage tank units, processing units, and separation units.

[0031] The storage tank unit is used to store recovered and purified dichloromethane, and to provide liquid alkali and process water to the treatment unit.

[0032] The processing unit is connected to the storage tank unit. The processing unit is used for alkaline washing treatment to recover dichloromethane and sends the treated material to the separation unit.

[0033] Specifically, the separation unit is connected to the treatment unit and the storage tank unit. The separation unit is the place where the aqueous phase and organic phase of the qualified alkaline washing material are separated. The separated alkaline washing wastewater is sent to the sewage treatment plant as a carbon source through the separation unit, and the aqueous phase and organic phase of the material washed by the treatment unit are separated through the separation unit and sent to the storage tank unit for storage.

[0034] Furthermore, the storage tank unit includes a dichloromethane recovery storage tank 11, a liquid alkali storage tank 12, and a wash water storage tank 14 connected to the treatment unit. The stored dichloromethane and liquid alkali are used for alkaline washing treatment of dichloromethane, and wash water is provided. The wash water storage tank 14 is used to recover the aqueous phase from subsequent treatments, which is beneficial to the environmental protection of the treated water through recycling.

[0035] The processing unit includes an alkaline washing tank 21. The recovered dichloromethane in the dichloromethane storage tank 11, the liquid alkali in the liquid alkali storage tank 12, and the washing water in the washing water storage tank 14 are sent into the alkaline washing tank 21. The material level of the alkaline washing tank 21 is determined by a set value. In this embodiment, the set value of the liquid level of the alkaline washing tank 21 is 80% of the height of the processing space. When the liquid level of the alkaline washing tank 21 reaches the set value, the alkaline washing tank 21 continues to discharge the material.

[0036] In practice, the processing unit also includes a holding vessel 22. The material in the alkali washing vessel 21 is fed into the holding vessel 22 for stirring and holding. Both the inlet and outlet of the alkali washing vessel 21 are equipped with regulating valves. The outlet regulating valve is equipped with a detector for detecting the content of dichloromethane. The detector is used to detect the content of acidic impurities in the liquid alkali and dichloromethane, such as common acidic impurities like hydrochloric acid and phenols. It can be installed on the valve or the pipeline connected to the valve inlet. The corresponding acidic impurity content is detected by the internal sensing element. The relevant detection methods and structures are all existing mature components, so they will not be described in detail here.

[0037] Inside the alkaline washing kettle 21, the acidic impurities in the recovered dichloromethane are neutralized by liquid alkali, thereby removing these acidic impurities and obtaining alkaline-washed material with high dichloromethane content. When detecting the dichloromethane content, if the content of acidic impurities is less than the limit value, the alkaline washing treatment is qualified. In this embodiment, the limit value of acidic impurities is ≤ 50 ppm.

[0038] Furthermore, the processing unit includes an oil-water separator a31. The material in the retention vessel 22 is fed into the oil-water separator a31 for phase separation. The liquid level in the retention vessel 22 is set to a set value. In this embodiment, the set value is 70% of the height of the processing space in the retention vessel 22. A valve is provided at the side outlet of the retention vessel 22.

[0039] The treatment unit also includes a washing tank 23. The wastewater separated in the oil-water separator a31 is discharged into the sewage treatment plant as a carbon source, and the separated organic phase is discharged into the washing tank 23. The side outlet of the oil-water separator a31 is connected to the sewage conveying system, so as to facilitate the delivery of the separated wastewater to the sewage treatment plant.

[0040] Specifically, the storage tank unit also includes a process water storage tank 13, and the separation unit also includes an oil-water separator b32 connected to the washing vessel 23. The process water storage tank 13 is connected to the washing vessel 23 to facilitate the supply of process water to the washing vessel 23. The liquid level of the washing vessel 23 is set to a value. In this embodiment, the set value is 85% of the height of the processing space inside the washing vessel 23.

[0041] In practice, a dichloromethane pH detector is installed at the bottom outlet of the washing vessel 23. The dichloromethane pH detector is an existing mature component. The dichloromethane pH at the outlet of the washing vessel 23 has a limit value. In this embodiment, the limit value is 6.0-8.0.

[0042] The storage tank unit also includes purified dichloromethane 15 connected to the oil-water separator b32, which is connected to the washing water storage tank 14.

[0043] The storage tank unit, processing unit and separation unit are connected by pipelines, and a transfer pump 5 is installed on the pipelines.

[0044] Working principle:

[0045] S1. Dichloromethane is pumped into the alkaline washing tank 21 via the dichloromethane recovery storage tank 11. Simultaneously, liquid alkali is pumped into the alkaline washing tank 21 via the liquid alkali storage tank 12, and washing water is pumped into the alkaline washing tank 21 via the washing water storage tank 14. When the liquid level in the alkaline washing tank 21 reaches the set value, the valve on the side outlet pipeline of the alkaline washing tank 21 and the bottom conveying pump 5 of the alkaline washing tank 21 are opened. The regulating valve on the top inlet pipeline of the residence tank 22 is adjusted, and the material in the alkaline washing tank 21 is discharged into the residence tank 22 via the bottom conveying pump 5 for stirring and residence. The content of dichloromethane at the outlet is measured. When the dichloromethane content at the outlet of the alkaline washing tank 21 is less than the limit value, the alkaline washing treatment is qualified. When the dichloromethane content at the outlet of the alkaline washing tank 21 is equal to the limit value, the feed flow rates of the dichloromethane recovery, liquid alkali, and washing water can no longer be adjusted.

[0046] S2. When the liquid level in the retention vessel 22 reaches the set value, open the valve on the side outlet pipeline of the retention vessel 22 and the bottom conveying pump 5 of the retention vessel 22, adjust the regulating valve on the top inlet pipeline of the oil-water separator a31, and discharge the material in the retention vessel 22 into the oil-water separator a31 for phase separation via the bottom conveying pump 5.

[0047] S3. The material in the oil-water separator a31 is allowed to stand and separate. The wastewater is discharged into the sewage treatment plant as a carbon source through the upper side outlet, and the organic phase is discharged into the washing tank 33 through the bottom outlet.

[0048] S4. Process water is pumped into washing tank 33 via process water storage tank 13 for washing treatment. When the liquid level in washing tank 33 reaches the set value, the valve on the side outlet pipeline of washing tank 33 and the bottom conveying pump 5 of washing tank 33 are opened. The regulating valve on the top inlet pipeline of oil-water separator b32 is adjusted to discharge the material in washing tank 33 into oil-water separator b32 via bottom conveying pump 5 for oil-water separation. The pH of the dichloromethane at the outlet is measured. When the pH of the dichloromethane at the outlet of washing tank 33 is less than the limit value, the washing treatment is qualified. The process water feed flow rate cannot be adjusted again until the pH of the dichloromethane at the outlet of washing tank 33 is equal to the limit value.

[0049] S5. The material in the oil-water separator b32 is allowed to stand and separate. The aqueous phase is discharged into the washing water storage tank 14 through the upper side outlet, and the organic phase is discharged into the purified dichloromethane storage tank 15 through the bottom outlet.

[0050] S6. Repeat the above steps.

[0051] Those skilled in the art should understand that this utility model is an improved device. Its innovation lies in the collaborative layout and specific structural relationship of the components, rather than the way the basic functions are implemented. The connection between the existing parts, the operating parameters and control logic are all common knowledge and conventional design choices in the field. Technical personnel can determine the appropriate specific implementation method by conducting limited experiments or referring to technical manuals according to the overall design requirements of the equipment, or by having a qualified professional manufacturer standardize and guide the operation according to mature industry standards. No creative labor is required.

[0052] The control method of this utility model is to control the device by manually starting and stopping the switch. The wiring diagram of the power element and the supply of power are common knowledge in the field. Since this utility model is mainly used to protect mechanical devices, the control method and wiring layout will not be explained in detail.

[0053] All standard parts used in this utility model can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, which will not be described in detail here.

Claims

1. A processing device for recovering dichloromethane in the production of acephate, characterized in that: Includes storage tank units, processing units, and separation units; The storage tank unit is used to store recovered and purified dichloromethane, and to supply liquid alkali and process water to the treatment unit; The processing unit is connected to the storage tank unit. The processing unit is used for alkaline washing treatment to recover dichloromethane and sends the treated material to the separation unit. The separation unit is connected to the treatment unit and the storage tank unit. The separation unit is the place where the aqueous phase and organic phase of the qualified alkaline washing material are separated. The separated alkaline washing wastewater is sent to the sewage treatment plant as a carbon source through the separation unit. The aqueous phase and organic phase of the material washed by the treatment unit are separated through the separation unit and sent to the storage tank unit for storage.

2. The processing device for recovering dichloromethane in the production of acephate according to claim 1, characterized in that: The storage tank unit includes a dichloromethane recovery tank (11), a liquid alkali tank (12), and a washing water tank (14) connected to the processing unit.

3. The processing device for recovering dichloromethane in the production of acephate according to claim 2, characterized in that: The processing unit includes an alkaline washing kettle (21), in which recovered dichloromethane from a dichloromethane storage tank (11), liquid alkali from a liquid alkali storage tank (12), and washing water from a washing water storage tank (14) are fed into the alkaline washing kettle (21).

4. The processing device for recovering dichloromethane in the production of acephate according to claim 3, characterized in that: The processing unit also includes a residence vessel (22). The material in the alkaline washing vessel (21) is sent into the residence vessel (22) for stirring and residence. The alkaline washing vessel (21) is equipped with regulating valves at both the inlet and outlet. The outlet regulating valve is equipped with a detector for detecting the dichloromethane content.

5. The processing device for recovering dichloromethane in the production of acephate according to claim 4, characterized in that: The processing unit includes an oil-water separator a (31), and the material in the residence vessel (22) is fed into the oil-water separator a (31) for phase separation.

6. The processing device for recovering dichloromethane in the production of acephate according to claim 5, characterized in that: The processing unit also includes a washing tank (23), where the wastewater separated in the oil-water separator a (31) is discharged into the sewage treatment plant as a carbon source, and the separated organic phase is discharged into the washing tank (23).

7. The processing device for recovering dichloromethane in the production of acephate according to claim 6, characterized in that: The storage tank unit also includes a process water storage tank (13), and the separation unit also includes an oil-water separator b (32) connected to the washing vessel (23). The process water storage tank (13) is connected to the washing vessel (23).

8. The processing device for recovering dichloromethane in the production of acephate according to claim 7, characterized in that: The storage tank unit also includes purified dichloromethane (15) connected to the oil-water separator b (32), which is connected to the washing water storage tank (14).

9. A treatment device for recovering dichloromethane in the production of acephate according to claim 8, characterized in that: The storage tank unit, processing unit and separation unit are connected by pipelines, and a transfer pump (5) is installed on the pipelines.

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