Wastewater pretreatment device in imazethapyr production

Abstract

The utility model belongs to the technical field of chemical production, and discloses a wastewater pretreatment device in imazethapyr production, which comprises a rectifying tower communicated with a preheater, and the preheater is communicated to a process wastewater conveying device and a first material inlet of the rectifying tower; the rectifying tower is communicated with a first cooler and a first reflux tank; the first reflux tank is communicated to a first reflux liquid inlet of the rectifying tower through a first reflux pump; the rectifying tower is communicated with a first collecting pump, the first collecting pump is respectively communicated with a first heater and the dealcoholization tower, and the first heater is communicated with the rectifying tower; the dealcoholization tower is sequentially communicated with a second cooler and a second reflux tank through a gas pipeline, and the second reflux tank is communicated to the dealcoholization tower through a second reflux pump; the dealcoholization tower is communicated with a second collection pump, the second collection pump is respectively communicated with a feed port of a second heater and the ethanol storage tank, and the second heater is communicated with the dealcoholization tower. The device is high in automation degree, good in pretreatment effect, high in safety and capable of effectively reducing labor and reducing cost.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical production, and particularly relates to a wastewater pretreatment device in the production of imazethapyr. Background Art

[0002] 2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-ethyl-3-pyridinecarboxylic acid (5,6-bis(4-methoxyphenyl)-2,3-diphenylthieno[3,2-b]furan) is abbreviated as imazethapyr, which is a white crystalline solid, acidic, with m.p. 169.0 - 173.0 °C, easily soluble in methanol and chloroform, and not easily soluble in benzene, toluene, water, etc. It is a side-chain amino acid synthesis inhibitor, having excellent control effects on gramineous weeds and some broad-leaved weeds in soybean fields and other leguminous plant fields. It is applied before or after the emergence of plants, with low toxicity and high efficiency, and does not require secondary application during the entire crop growth cycle. Therefore, it has a wide market application and good prospects.

[0003] During the production process of imazethapyr, by-products ethanol will be generated. The wastewater produced after extracting ethanol contains about 22% methanol, 10% ethanol, and 2% dichloromethane. If this wastewater is directly transported to the biochemical treatment system, it will cause great harm to the biochemical treatment system, resulting in the inability of the biochemical system to effectively treat, and further affecting the production of the entire product line. The existing wastewater pretreatment device is through triple-effect distillation. The COD of the distilled water is less than 10000 mg / L, and it can be subjected to subsequent biochemical treatment. However, the COD content in the distilled water obtained by this treatment is still relatively high (methanol and ethanol enter the distilled water with the evaporation of water), and the energy consumption is large, which is not conducive to the continuous operation of production, resulting in problems such as poor production continuity, low production capacity, low safety, and poor product stability. Summary of the Invention

[0004] The technical problem to be solved by the utility model is to provide a wastewater pretreatment device in the production of imazethapyr. This device overcomes the defects in the prior art, has a simple structure, can realize automatic control and continuous production, has good wastewater pretreatment effect, and greatly reduces the COD content in the wastewater.

[0005] To solve the above technical problem, the technical solution of the utility model is:

[0006] A wastewater pretreatment device in imazethapyr production, comprising a distillation column with a preheater connected to its upper part. The feed inlet of the preheater is connected to a process wastewater conveying device, and the discharge outlet of the preheater is connected to the first material inlet of the distillation column. The top of the distillation column is sequentially connected with a first cooler and a first reflux tank through a gas transmission pipeline. The bottom of the first reflux tank is connected to the first reflux liquid inlet at the top of the distillation column through a first reflux pump. The bottom of the distillation column is connected with a first collection pump, and the discharge outlet of the first collection pump is respectively connected to the feed inlet of a first heater and the feed inlet in the middle of a de-alcoholization column. The discharge outlet of the first heater is connected to the second reflux liquid inlet at the bottom of the distillation column (the function of the first heater is to collect the distillation brine and preheat the process condensate, reduce the temperature of the collected distillation brine, and preheat the process condensate before it enters the tower kettle. The distillation brine flows through the outer ring of the preheater, and the process condensate flows through the inner ring of the preheater). The top of the de-alcoholization column is sequentially connected with a second cooler and a second reflux tank through a gas transmission pipeline. The bottom of the second reflux tank is connected to the third reflux liquid inlet at the top of the de-alcoholization column through a second reflux pump. The bottom of the de-alcoholization column is connected with a second collection pump, and the discharge outlet of the second collection pump is respectively connected to the feed inlet of a second heater and an ethanol storage tank. The discharge outlet of the second heater is connected to the fourth reflux liquid inlet at the bottom of the de-alcoholization column. Remote thermometers, remote pressure gauges and liquid level gauges are respectively arranged on the side walls of the distillation column and the de-alcoholization column. The first collection pump, the second collection pump, the first reflux pump, the second reflux pump, the remote thermometer, the remote pressure gauge and the liquid level gauge are all electrically connected to a DCS automatic control system.

[0007] Preferably, the first reflux tank is provided with a collection pipeline, and the first reflux pump is arranged on the collection pipeline; the mixed liquid containing methanol, ethanol, dichloromethane and water cooled by the first cooler is transported to the feed inlet of the distillation column through the collection pipeline and the reflux pump for secondary separation (and control the top temperature to reflux out the excess water to reduce the water content during collection).

[0008] Preferably, discharge valves are respectively arranged at the bottoms of the distillation column and the de-alcoholization column, and the discharge valves are all electrically connected to the DCS automatic control system.

[0009] Preferably, remote flow meters and feed valves are respectively arranged on the feed pipelines of the distillation column and the de-alcoholization column, and the flow meters and the feed valves are all electrically connected to the DCS automatic control system.

[0010] The feed valve and the discharge valve are both automatic valves, with the model number JG60-Q2-DA-MF3-40-A-16, and the manufacturer is Shanghai Huhang Valve Co., Ltd. The remote flow meter model is LZ40-16, and the manufacturer is Jiangsu Hongguang Instrument Factory Co., Ltd.

[0011] Preferably, the first collection pump, the second collection pump, the first reflux pump, and the second reflux pump are all 316L stainless steel magnetic centrifugal pumps, with the model IMC50-32-160P, and the manufacturer is Shanghai Benuo Pump Valve Co., Ltd.

[0012] Preferably, the liquid level gauge is set as a double liquid level gauge, which includes a magnetic flap liquid level gauge and a double flange pressure transmitter. The first collection pump and the second collection pump are both electrically connected to the DCS automatic control system through the discharge valve switch. The double flange pressure transmitter sends a signal to the DCS. The DCS automatic control system uses PID to control the liquid level height and timely adjusts the opening of the discharge valve. The product model of the double flange pressure transmitter is MAT3851DP / GP, and the manufacturer is Jiangsu Hongguang Instrument Factory Co., Ltd.

[0013] Preferably, the model of the remote thermometer is PT100-80-16, and the manufacturer is Tianchang Instrument Factory in Anhui Province; the model of the remote pressure gauge is LH3851HT, and the manufacturer is Jiangsu Hongguang Instrument Factory Co., Ltd.

[0014] Preferably, the preheater is a shell and tube heat exchanger, with the model D500*2000, and the manufacturer is Feicheng Jinta Machinery Technology Co., Ltd.

[0015] Preferably, the first cooler and the second cooler are both shell and tube heat exchangers, with the model D800*2000, and the manufacturer is Feicheng Jinta Machinery Technology Co., Ltd.

[0016] Preferably, the first heater and the second heater are both vertical shell and tube heat exchangers, with the model D600*2000, and the manufacturer is Feicheng Jinta Machinery Technology Co., Ltd.

[0017] Due to the adoption of the above technical solutions, the beneficial effects of the present utility model are as follows:

[0018] The present utility model reduces energy consumption through two-stage rectification, fully separates methanol and ethanol in the wastewater, reduces the COD of the wastewater, ensures the uniformity of the treated water, and the COD content is lower than 10,000 mg / L. In addition, through automatic control, the operation parameters are reasonably allocated, so as to achieve precise control of the material blending and prevent the occurrence of unqualified treated water.

[0019] In summary, the present utility model has a high degree of automation, good pretreatment effect, high safety, can effectively reduce the labor force and lower the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of an embodiment of the present utility model;

[0021] In the figure, 1 is a preheater; 2 is a rectification column; 3 is a first cooler; 4 is a first reflux drum; 5 is a first reflux pump; 6 is a first collection pump; 7 is a first heater; 8 is a de-alcoholization column; 9 is a second cooler; 10 is a second reflux drum; 11 is a second reflux pump; 12 is a second collection pump; 13 is a second heater. Detailed implementation mode

[0022] The following further elaborates on the present utility model in conjunction with the accompanying drawings and embodiments.

[0023] Embodiment 1:

[0024] As Figure 1 shown, a wastewater pretreatment device in imazethapyr production includes a rectification column 2 with a preheater 1 connected to its upper part. The feed inlet of the preheater 1 is connected to a process wastewater conveying device (not marked), and the discharge outlet of the preheater 1 is connected to the first material inlet of the rectification column 2. The top of the rectification column 2 is sequentially connected with a first cooler 3 and a first reflux drum 4 through a gas transmission pipeline. The bottom of the first reflux drum 4 is connected to the first reflux liquid inlet at the top of the rectification column 2 through a first reflux pump 5. The bottom of the rectification column 2 is connected with a first collection pump 6. The discharge outlet of the first collection pump 6 is respectively connected to the feed inlet of a first heater 7 and the feed inlet in the middle of a de-alcoholization column 8. The discharge outlet of the first heater 7 is connected to the second reflux liquid inlet at the bottom of the rectification column 2. The top of the de-alcoholization column 8 is sequentially connected with a second cooler 9 and a second reflux drum 10 through a gas transmission pipeline. The bottom of the second reflux drum 10 is connected to the third reflux liquid inlet (not marked) at the top of the de-alcoholization column 8 through a second reflux pump 11. The bottom of the de-alcoholization column 8 is connected with a second collection pump 12. The second collection pump 12 is also respectively connected to the feed inlet of a second heater 13 and an ethanol storage tank (not marked). The discharge outlet of the second heater 13 is connected to the fourth reflux liquid inlet (not marked) at the bottom of the de-alcoholization column 8. Remote temperature gauges (not marked), remote pressure gauges (not marked) and liquid level gauges (not marked) are respectively arranged on the side walls of the rectification column 2 and the de-alcoholization column 8. The first collection pump 6, the second collection pump 12, the first reflux pump 5, the second reflux pump 11, the remote temperature gauge, the remote pressure gauge and the liquid level gauge are all electrically connected to a DCS automatic control system.

[0025] During actual production: The process wastewater is preheated to 59 - 62 °C by the preheater 1 and then enters the rectification column 2. In the rectification column 2, the rectification separation of alcohols and saline water is carried out, and the bottom material temperature is maintained at 105 - 108 °C. The bottom water of the rectification column 2 is transported into the de-alcoholization column 8 through the first collection pump 6 for secondary rectification separation. The top temperature of the de-alcoholization column 8 is maintained at 92 - 95 °C, and the bottom temperature is maintained at 108 - 112 °C. Through the above treatment, heat energy can be saved and heat energy consumption can be reduced, ensuring that the water discharged from the de-alcoholization column 8 is 10000 mg / L, and ensuring that the COD of the subsequent triple-effect distilled water is lower than 10000 mg / L.

[0026] It should be understood that these embodiments are only used to illustrate the present utility model and not to limit the scope of the present utility model. In addition, it should be understood that after reading the content taught by the present utility model, those skilled in the art can make various changes or modifications to the present utility model, and these equivalent forms also fall within the scope defined by the appended claims of this application.

Claims

1. A wastewater pretreatment device for the production of imidacloprid, characterized in that: The invention comprises a distillation tower connected with a preheater at the top, the feed port of the preheater is connected to the process wastewater conveying device, and the discharge port of the preheater is connected to the first material inlet of the distillation tower; the top of the distillation tower is connected with a first cooler and a first reflux tank in sequence through a gas pipeline, and the bottom of the first reflux tank is connected to the first reflux liquid inlet at the top of the distillation tower through a first reflux pump; the bottom of the distillation tower is connected with a first collection pump, and the discharge port of the first collection pump is respectively connected to the feed port of the first heater and the feed port in the middle of the dealcoholization tower, and the discharge port of the first heater is connected to the second reflux liquid inlet at the bottom of the distillation tower; the top of the dealcoholization tower is connected with a first cooler and a first reflux tank in sequence through a gas pipeline, and the bottom of the first reflux tank is connected to the first reflux liquid inlet at the top of the distillation tower through a first reflux pump. The second cooler is connected to the second reflux tank, and the bottom of the second reflux tank is connected to the third reflux liquid inlet at the top of the dealcoholization tower through the second reflux pump; the bottom of the dealcoholization tower is connected to the second collection pump, and the discharge port of the second collection pump is respectively connected to the feed port of the second heater and the ethanol storage tank, and the discharge port of the second heater is connected to the fourth reflux liquid inlet at the bottom of the dealcoholization tower; the side walls of the distillation tower and the dealcoholization tower are also respectively provided with a remote thermometer, a remote pressure gauge and a liquid level gauge; the first collection pump, the second collection pump, the first reflux pump, the second reflux pump, the remote thermometer, the remote pressure gauge and the liquid level gauge are all electrically connected to the DCS automatic control system.

2. The wastewater pretreatment device in the production of imidacloprid as claimed in claim 1, characterized in that: The bottoms of the distillation tower and the dealcoholization tower are both provided with discharge valves, and the discharge valves are both electrically connected to the DCS automatic control system.

3. The wastewater pretreatment device in the production of imidacloprid as claimed in claim 1, characterized in that: The feed pipelines of the distillation tower and the dealcoholization tower are both provided with a remote flow meter and a feed valve, and the flow meter and the feed valve are both electrically connected to a DCS automatic control system.

4. The wastewater pretreatment device in the production of imazethapyr according to claim 1, characterized in that: The liquid level gauge is configured as a dual liquid level gauge, which includes a magnetic flap liquid level gauge and a dual flange pressure transmitter.

5. The wastewater pretreatment device in the production of imazethapyr according to claim 1, characterized in that: The preheater, the first cooler and the second cooler are all shell and tube heat exchangers.

6. The wastewater pretreatment device in the production of imazethapyr according to claim 1, characterized in that: The first heater and the second heater are both vertical shell and tube heat exchangers.

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