Combined device for rectifying and purifying recovered crude phenol

Abstract

The utility model relates to a combined device for rectifying and purifying recovered crude phenol, and belongs to the technical field of chemical production devices and rectifying and purifying. The device is formed by combining a distillation still, a rectifying tower, an evaporation inclined pipe, a condenser, a liquid separation tank, a U-shaped bent pipe, an impurity receiving tank, a front distillation receiving tank, a reflux condenser, a certified product receiving tank, a water heater, a vacuum ejector and the like. The innovation point is that the design of an evaporation inclined pipe is introduced, a liquid separation tank and a U-shaped bent pipe are arranged, and a water heater for cooling phenol steam is designed; according to the technical scheme, the combined device for rectifying and purifying the recovered phenol crude product effectively solves the problem that an evaporation pipeline is blocked due to crystallization in the rectifying and purifying process of the recovered phenol, solves the problem that a condenser is blocked by phenol crystallization in the operation process, and solves the problem that impurities are not easily brought out due to backflow; the combined device for rectifying and purifying the recovered crude phenol product disclosed by the utility model also has the characteristics of high product purity and convenience in operation.

Description

Technical Field

[0001] This utility model belongs to the field of chemical production equipment and distillation purification technology, and specifically relates to a combined device for distillation purification of recovered crude phenol. Background Technology

[0002] Phenol, also known as carbolic acid, is the simplest phenolic organic compound. It is a colorless crystal at room temperature and is toxic. Its molecular formula is C6H5OH, and its molecular weight is 94.11. Phenol is a basic chemical raw material, widely used in resin synthesis and the synthesis of pharmaceutical intermediates. Phenol is corrosive, slightly soluble in water, and readily soluble in organic solvents; at temperatures above 65°C, it is miscible with water in any proportion. Phenol turns pink when exposed to air.

[0003] In the process of treating the mother liquor from the centrifugation of cyclohexylphenylglycine, approximately 60% phenol is recovered. This recovered phenol is dark red in color and has a high impurity content, making it unsuitable for direct use in chemical production. Therefore, the recovered phenol must be purified by distillation. Previously, direct distillation methods were ineffective in removing impurities and pigments; simple distillation yields were low, and operating costs were relatively high. Furthermore, during the distillation process, phenol is prone to crystallization in the condenser or pipelines due to temperature fluctuations, leading to blockages. This not only affects production efficiency but also poses significant safety risks due to pipeline blockages during production. Summary of the Invention

[0004] To address the aforementioned problems, this utility model discloses a combined device for the distillation and purification of recovered crude phenol. Its innovations include the introduction of an inclined evaporator design, the installation of a separator, the addition of a U-shaped bend, and the design of a water heater for cooling phenol vapor. This combined device effectively solves the problems of phenol crystallization and blockage of evaporation pipes due to temperature reduction during the distillation and purification process, the problem of condenser blockage by phenol crystallization during operation, and the problem of impurities being easily carried away by reflux during atmospheric distillation. Furthermore, this combined device for the distillation and purification of recovered crude phenol also features high product purity, high production efficiency, and convenient operation.

[0005] The present invention relates to a combined device for the distillation and purification of crude phenol, comprising: a distillation kettle, a crude product inlet, a steam inlet, a steam trap, a distillation column, an evaporation inclined tube, a condenser, a water heater, a hot water pump, a water inlet pipe, a water return pipe, a condensate riser, a liquid distribution control valve, a liquid distribution tank, a U-bend, an impurity switching valve, an impurity receiving tank, a distillate transfer valve, a fore-distillate switching valve, a fore-distillate receiving tank, a reflux condenser, a vacuum buffer tank, a vacuum ejector, a positive product switching valve, a positive product receiving tank, a vacuum pump water tank, and a vacuum... The distillation vessel is characterized by having a crude product inlet at the top and a steam inlet and a drain valve on its outer side. The drain valve outlet is connected to a water heater and extends through a pipe into the water heater. A hot water pump is located at the lower outer side of the water heater and connected to a water inlet pipe. A return water pipe is connected to the upper part of the water heater. The water inlet pipe connects upwards to the lower shell side of the condenser, and the return water pipe connects to the upper shell side of the condenser. The distillation column is located in... Above the distillation kettle, the top of the distillation column is connected to the condenser via an evaporation bend. The lower outlet of the condenser is connected to a condensate riser, which is connected to the middle of a separatory tank via a separatory control valve. A U-shaped bend is connected to one side of the upper part of the separatory tank, and this bend is also connected to the upper part of the distillation kettle. An impurity switching valve is installed at the lower part of the separatory tank, connecting downwards to an impurity receiving tank. A distillate transfer valve is also connected between the separatory tank and the impurity switching valve. A fore-distillate switching valve is connected directly below the condensate riser. The distillation switching valve is connected downwards to the pre-distillation receiving tank. A reflux condenser is installed at the top of the pre-distillation receiving tank. The upper outlet of the reflux condenser is connected to the pre-distillation vacuum valve through a pipe. The pre-distillation vacuum valve is connected to the vacuum buffer tank. The vacuum buffer tank is connected to the vacuum ejector. The other side of the condensate riser is connected to the product switching valve. The product switching valve is connected to the product receiving tank. A reflux condenser is installed at the top of the product receiving tank. The upper outlet of the reflux condenser is connected to the product vacuum valve through a pipe. The product vacuum valve is connected to the vacuum buffer tank.

[0006] Preferably, the combined apparatus for the distillation and purification of crude phenol as described in this utility model is characterized in that the distillation column is equipped with an 80-100mm thick glass wool insulation layer on the outside and has 6-8 layers of packing modules inside. This design aims to reduce energy consumption and facilitate packing replacement.

[0007] Preferably, the combined apparatus for the distillation and purification of crude phenol as described in this utility model is characterized in that the evaporation inclined tube has a diameter of 125-150 mm, is wrapped with an 80-100 mm thick rubber-plastic insulation layer, and forms an angle of 15-30° with the horizontal plane. This design aims to allow the vaporized phenol to quickly enter the condenser, avoiding pipe blockage caused by phenol crystallization during the flow process.

[0008] Preferably, the combined apparatus for the distillation and purification of crude phenol as described in this utility model is characterized in that the condenser is a shell-and-tube condenser, vertically installed, with a heat exchange area of ​​80-100 m². 2 The purpose of this design is to allow the liquefied phenol to pass through quickly, preventing it from crystallizing upon cooling and causing blockages in the condenser.

[0009] Preferably, the combined apparatus for the distillation and purification of crude phenol as described in this utility model is characterized in that the U-shaped bend has a diameter of 40-50 mm, an extension length of 12-15 m, and a U-bend depth of 4-6 m. The purpose of adding the U-shaped bend is to allow the distilled water to overcome the positive pressure generated by the high temperature of the distillation vessel and flow smoothly back into the distillation vessel, thereby realizing the circulation of impurities carried out during distillation.

[0010] Preferably, the combined apparatus for the distillation and purification of crude phenol as described in this utility model is characterized in that the diameter of the condensate vertical pipe is 125-150 mm, and it is connected to the positive product switching valve via an upwardly inclined short pipe. This design aims to prevent a small amount of low-purity phenol from flowing into the positive product receiving tank.

[0011] The combined device for the distillation and purification of crude phenol described in this utility model has the following significant advantages: 1. The addition of an evaporation inclined tube ensures the rapid passage of phenol distillate gas, avoiding pipe blockage caused by phenol crystallization; 2. The addition of a separator effectively separates impurities and distilled water; and the addition of a water heater ensures that phenol crystallization is prevented during the distillation process due to excessively low cooling water temperature, thereby effectively avoiding safety risks caused by pipe blockage. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0013] Figure 1 This is an operational flow chart and plan view of a combined device for the distillation and purification of crude phenol, as described in an embodiment of the present invention.

[0014] Figure 1In the middle section: Distillation kettle 01, crude product inlet 02, steam inlet 03, steam trap 04, distillation column 05, evaporation inclined tube 06, condenser 07, water heater 08, hot water pump 09, water supply pipe 10, water return pipe 11, condensate riser 12, liquid distribution control valve 13, liquid distribution tank 14, U-bend 15, distillate water transfer valve 16, impurity switching valve 17, impurity receiving tank 18, fore-distillate switching valve 19, fore-distillate receiving tank 20, reflux condenser 21, vacuum buffer tank 22, vacuum ejector 23, vacuum circulation pump 24, vacuum pump water tank 25, genuine product switching valve 26, genuine product receiving tank 27, fore-distillate vacuum valve 28, genuine product vacuum valve 29. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this utility model clearer, the following description is provided in conjunction with... Figure 1 The specific embodiments of this implementation will be further described.

[0016] This specific embodiment describes a combined device for the distillation and purification of crude phenol, comprising: a distillation kettle 01, a crude product inlet 02, a steam inlet 03, a steam trap 04, a distillation column 05, an evaporation inclined tube 06, a condenser 07, a water heater 08, a hot water pump 09, a water supply pipe 10, a water return pipe 11, a condensate riser 12, a liquid distribution control valve 13, a liquid distribution tank 14, a U-shaped bend 15, a distillate water transfer valve 16, an impurity switching valve 17, an impurity receiving tank 18, a fore-distillation switching valve 19, a fore-distillation receiving tank 20, a reflux condenser 21, a vacuum buffer tank 22, a vacuum ejector 23, a vacuum circulation pump 24, a vacuum pump water tank 25, a positive product switching valve 26, a positive product receiving tank 27, a fore-distillation vacuum valve 28, and a positive product vacuum valve 29.

[0017] This specific embodiment describes a combined apparatus for the distillation and purification of crude phenol, characterized in that: a crude product inlet 02 is provided at the upper part of the distillation kettle 01, and a steam inlet 03 and a drain valve 04 are respectively provided on the outer side. The outlet of the drain valve 04 is connected to a water heater 08 and extends into the water heater 08 through a pipe. A hot water pump 09 is provided at the lower part of the outer side of the water heater 08, and the hot water pump 09 is connected to a water inlet pipe 10. A water return pipe 11 is connected to the upper part of the water heater 08. The water inlet pipe 10 is connected upward to the lower part of the shell side of the condenser 07, and the water return pipe 11 is connected to the upper part of the shell side of the condenser 07. A distillation column 05 is provided above the distillation kettle 01. The top of the distillation column 05 is connected to the condenser 07 through an evaporation inclined tube 06. The lower outlet of the condenser 07 is connected to a condensate vertical pipe 12. The condensate vertical pipe 12 is connected to the middle part of a liquid separator 14 through a liquid separation control valve 13. A U-shaped bend is connected to the upper side of the liquid separator 14. Pipe 15 is connected to the upper part of distillation vessel 01 via U-shaped bend 15. An impurity switching valve 17 is installed at the lower part of the separator 14, and the impurity switching valve 17 is connected downwards to the impurity receiving tank 18. A distillate transfer valve 16 is also connected between the separator 14 and the impurity switching valve 17. A fore-distillate switching valve 19 is connected directly below the condensate riser 12, and the fore-distillate switching valve 19 is connected downwards to the fore-distillate receiving tank 20. A reflux condenser 21 is installed at the upper part of the fore-distillate receiving tank 20. The upper outlet is connected to a pre-distillation vacuum valve 28 via a pipe. The pre-distillation vacuum valve 28 is connected to a vacuum buffer tank 22. The vacuum buffer tank 22 is connected to a vacuum ejector 23. The other side of the condensate riser 12 is connected to a product switching valve 26. The product switching valve 26 is connected to a product receiving tank 27. A reflux condenser 21 is installed on the upper part of the product receiving tank 27. The upper outlet of the reflux condenser 21 is connected to a product vacuum valve 29 via a pipe. The product vacuum valve 29 is connected to the vacuum buffer tank 22.

[0018] The combined apparatus for the distillation and purification of crude phenol as described in this specific embodiment has the following simple operation process: First, the crude phenol is pumped into the distillation kettle 01 through the crude product inlet 02. The fore-distillate switching valve 19 and the positive product switching valve 26 are closed, and the liquid separation control valve 13 is opened. Stirring and steam heating are started. Hot water from the drain valve 04 flows into the water heater 08 for collection and later use. When the recovered phenol in the distillation kettle 01 reaches its boiling point, the recovered phenol vapor enters the condenser 07 along the distillation column 05 and the evaporation inclined tube 06 for condensation. The condensate, which is mostly water, enters the liquid separation tank 14 through the liquid separation control valve 13 for separation of impurities and distilled water. The impurities sink, and the distilled water rises and flows back to the distillation kettle 01 through the upper outlet of the liquid separation tank 14 along the U-shaped bend 15. When the amount of distilled impurities no longer increases, the impurity switching valve 17 is opened. The deposited impurities are allowed to flow into the impurity receiving tank 18, and then the distillate water transfer valve 16 is opened to transfer the distillate water to the next process. Next, the liquid separation control valve 13 is closed, and the pre-distillation switching valve 19 and vacuum circulation pump 24 are opened to perform vacuum distillation on the recovered phenol after removing water and impurities. The hot water pump 09 is turned on to allow hot water to circulate between the water inlet pipe 10, condenser 07, return water pipe 11, and water heater 08, so that the temperature in the condenser 07 is maintained so that phenol cannot crystallize. The condensate with low phenol content in the early stage of distillation flows into the pre-distillation receiving tank 20 as the pre-distillation fraction. When the phenol content in the condensate is detected to meet the technical requirements, the positive product switching valve 26 is opened and the pre-distillation switching valve 19 is closed, allowing the positive phenol to flow into the positive product receiving tank 27. After one cycle of recovered phenol distillation and purification is completed, the crude recovered phenol is added again for the next batch of operation.

[0019] Furthermore, the combined apparatus for the distillation and purification of crude phenol described in this specific embodiment is characterized in that the distillation column is equipped with an 80-100mm thick glass wool insulation layer on the outside and has 6-8 layers of packing modules inside. This design aims to reduce energy consumption and facilitate packing replacement.

[0020] Furthermore, the combined apparatus for the distillation and purification of crude phenol described in this specific embodiment is characterized in that the evaporation inclined tube has a diameter of 125-150 mm, is wrapped with an 80-100 mm thick rubber-plastic insulation layer, and forms an angle of 15-30° with the horizontal plane. This design aims to allow the vaporized phenol to quickly enter the condenser, avoiding pipe blockage caused by phenol crystallization during the flow process.

[0021] Furthermore, the combined apparatus for the distillation and purification of crude phenol as described in this specific embodiment is characterized in that the condenser is a shell-and-tube condenser, vertically installed, with a heat exchange area of ​​80-100 m². 2The purpose of this design is to allow the liquefied phenol to pass through quickly, preventing it from crystallizing upon cooling and causing blockages in the condenser.

[0022] Furthermore, the combined apparatus for the distillation and purification of crude phenol described in this specific embodiment is characterized in that the U-shaped bend has a diameter of 40-50 mm, an extension length of 12-15 m, and a U-bend depth of 4-6 m. The purpose of adding the U-shaped bend is to allow the distilled water to overcome the positive pressure generated by the high temperature of the distillation vessel and flow smoothly back into the distillation vessel, thereby realizing the circulation of impurities carried out during distillation.

[0023] Furthermore, in the specific embodiment of this invention, the combined apparatus for the distillation and purification of recovered crude phenol is characterized in that the condensate vertical pipe has a diameter of 125-150 mm and is connected to the positive product switching valve via an upwardly inclined short pipe. This design aims to prevent a small amount of low-purity phenol from flowing into the positive product receiving tank.

[0024] The combined device for the distillation and purification of crude phenol described in this utility model has the following significant advantages: 1. The addition of an evaporation inclined tube ensures the rapid passage of phenol distillate gas, avoiding pipe blockage caused by phenol crystallization; 2. The addition of a separator effectively separates impurities and distilled water; and the addition of a water heater ensures that phenol crystallization is prevented during the distillation process due to excessively low cooling water temperature, thereby effectively avoiding safety risks caused by pipe blockage.

[0025] Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model shall be included within the protection scope of this utility model. The protection scope of this utility model shall conform to the widest range consistent with the principles and novel features described herein.

Claims

1. A combination apparatus for rectification purification of a crude recovered phenol product, comprising: The distillation kettle, crude product inlet, steam inlet, drain valve, rectification tower, evaporation inclined pipe, condenser, water heater, hot water pump, water inlet pipe, water return pipe, condensate vertical pipe, liquid separation control valve, liquid separation tank, U-shaped bend, impurity switching valve, impurity receiving tank, steam water transfer valve, fore-cut switching valve, fore-cut receiving tank, reflux condenser, vacuum buffer tank, vacuum ejector, product switching valve, product receiving tank, vacuum pump tank, vacuum circulating pump, fore-cut vacuum valve, product vacuum valve, characterized in that the upper part of the distillation kettle is provided with a crude product inlet, and the outer side is respectively provided with a steam inlet and a drain valve, the outlet of the drain valve is connected with the water heater and extends into the water heater through a pipeline, the outer side of the lower part of the water heater is provided with a hot water pump, the hot water pump is connected with the water inlet pipe, the upper part of the water heater is connected with the water return pipe, the water inlet pipe is connected with the lower part of one side of the shell side of the condenser, the water return pipe is connected with the upper part of one side of the shell side of the condenser, the rectification tower is arranged above the distillation kettle, the top of the rectification tower is connected with the condenser through the evaporation inclined pipe, the lower part of the condenser is connected with the condensate vertical pipe, the condensate vertical pipe is connected with the middle part of the liquid separation tank through the liquid separation control valve, the upper part of one side of the liquid separation tank is connected with the U-shaped bend and connected with the upper part of the distillation kettle through the U-shaped bend, the lower part of the liquid separation tank is provided with the impurity switching valve, the impurity switching valve is connected with the impurity receiving tank, the liquid separation tank and the impurity switching valve are further connected with the steam water transfer valve, the condensate vertical pipe is connected with the fore-cut switching valve below, the fore-cut switching valve is connected with the fore-cut receiving tank, the fore-cut receiving tank is provided with the reflux condenser at the upper part, the outlet of the upper part of the reflux condenser is connected with the fore-cut vacuum valve through a pipeline, the fore-cut vacuum valve is connected with the vacuum buffer tank, the vacuum buffer tank is connected with the vacuum ejector, the other side of the condensate vertical pipe is connected with the product switching valve, the product switching valve is connected with the product receiving tank, the product receiving tank is provided with the reflux condenser at the upper part, the outlet of the upper part of the reflux condenser is connected with the product vacuum valve through a pipeline, and the product vacuum valve is connected with the vacuum buffer tank.

2. A combination apparatus for purifying crude recovered phenol by rectification according to claim 1, characterized in that, The outer side of the rectification tower is additionally provided with a glass wool insulation layer with a thickness of 80-100 mm, and the inside is provided with 6-8 layers of packing modules.

3. A combination apparatus for purifying crude recovered phenol by rectification according to claim 1, characterized in that, The evaporation inclined pipe has a diameter of 125-150 mm, and is wrapped with an rubber-plastic cotton insulation layer with a thickness of 80-100 mm, and the evaporation inclined pipe forms an angle of 15-30° with the horizontal plane.

4. A combination apparatus for purifying crude recovered phenol by rectification according to claim 1, characterized in that, The condenser is a column-tube type condenser, vertically installed upright, and the heat exchange area reaches 80-100 m 2 .

5. A combination apparatus for purifying crude recovered phenol by rectification according to claim 1, characterized in that, The U-shaped bend has a diameter of 40-50 mm and a length of 12-15 m, and the depth of the U-shaped bend is 4-6 m.

6. A combination apparatus for purifying crude recovered phenol by rectification according to claim 1, characterized in that, The condensate vertical pipe has a diameter of 125-150 mm, and is connected with the product switching valve through an upwardly inclined short pipe.

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