A production plant for mono- and di-pentaerythritol

Abstract

This utility model discloses a production apparatus for monopentaerythritol and dipentaerythritol, comprising a condensation kettle, an aldehyde removal kettle, an evaporator, a first centrifuge, a first crystallization kettle, a second centrifuge, a first dissolving kettle, a hydrolysis tower, a first decolorization kettle, a first filter press, a second crystallization kettle, a first washing device, a collection tank, a third centrifuge, a second washing device, a second dissolving kettle, a second decolorization kettle, a second filter press, a third crystallization kettle, and a fourth centrifuge. The outlet of the condensation kettle is connected to the inlet of the aldehyde removal kettle, the outlet of the aldehyde removal kettle is connected to the inlet of the evaporator, the outlet of the evaporator is connected to the inlet of the first centrifuge, and the liquid outlet of the first centrifuge is connected to the inlet of the first crystallization kettle. This utility model can produce both monopentaerythritol and dipentaerythritol, making full use of raw materials, improving raw material utilization rate, reducing the generation of by-products and waste, reducing resource waste, and improving economic efficiency.

Description

Technical Field

[0001] This utility model relates to a production apparatus for monopentaerythritol and dipentaerythritol. Background Technology

[0002] Currently, both pentaerythritol monophosphate and dipentaerythritol are polyol organic compounds with broad application prospects in the chemical industry. However, some existing production equipment can only produce pentaerythritol and not dipentaerythritol. For example, the production equipment disclosed in Chinese Patent No. CN202226794U can only produce pentaerythritol and not dipentaerythritol. Using such equipment will result in the underutilization of raw materials. The components in the raw materials that could have produced dipentaerythritol will become byproducts or waste, leading to low utilization of raw materials, resource waste, and consequently, poor economic benefits. Utility Model Content

[0003] The technical problem to be solved by this utility model is to overcome the defects of the prior art and provide a production device for monopentaerythritol and dipentaerythritol. It can produce both monopentaerythritol and dipentaerythritol, make full use of raw materials, improve the utilization rate of raw materials and reduce the generation of by-products and waste, thereby reducing resource waste and improving economic efficiency.

[0004] To solve the above-mentioned technical problems, the technical solution of this utility model is: a production apparatus for monopentaerythritol and dipentaerythritol, comprising a condensation kettle, an aldehyde removal kettle, an evaporator, a first centrifuge, a first crystallization kettle, a second centrifuge, a first dissolving kettle, a hydrolysis tower, a first decolorization kettle, a first filter press, a second crystallization kettle, a first washing device, a collection tank, a third centrifuge, a second washing device, a second dissolving kettle, a second decolorization kettle, a second filter press, a third crystallization kettle, and a fourth centrifuge;

[0005] The outlet of the condensation vessel is connected to the inlet of the formaldehyde removal vessel, the outlet of the formaldehyde removal vessel is connected to the inlet of the evaporator, the outlet of the evaporator is connected to the inlet of the first centrifuge, the liquid outlet of the first centrifuge is connected to the inlet of the first crystallization vessel, the outlet of the first crystallization vessel is connected to the inlet of the second centrifuge, the solid outlet of the second centrifuge is connected to the inlet of the first solvent vessel, the outlet of the first solvent vessel is connected to the inlet of the hydrolysis tower, the liquid phase outlet at the bottom of the hydrolysis tower is connected to the inlet of the first decolorization vessel, the outlet of the first decolorization vessel is connected to the inlet of the first filter press, and the outlet of the first filter press is connected to the... The inlet of the second crystallization vessel is connected to the outlet of the second crystallization vessel, which is connected to the inlet of the first washing vessel. The solid outlet of the first washing vessel is connected to the collection tank, and the outlet of the collection tank is connected to the inlet of the third centrifuge. The liquid outlet of the first washing vessel is connected to the inlet of the second washing vessel, and the outlet of the second washing vessel is connected to the inlet of the second dissolving vessel. The outlet of the second dissolving vessel is connected to the inlet of the second decolorizing vessel, and the outlet of the second decolorizing vessel is connected to the inlet of the second filter press. The outlet of the second filter press is connected to the inlet of the third crystallization vessel, and the outlet of the third crystallization vessel is connected to the inlet of the fourth centrifuge.

[0006] The condensation vessel has a formaldehyde inlet, an acetaldehyde inlet, a first alkali inlet, and a first formic acid inlet; the formaldehyde removal vessel has a hydrogen peroxide inlet, a second alkali inlet, and a second formic acid inlet; the first dissolving vessel has a first solvent inlet; the first decolorizing vessel has a first activated carbon inlet; the second dissolving vessel has a second solvent inlet; and the second decolorizing vessel has a second activated carbon inlet.

[0007] Furthermore, the production apparatus for monopentaerythritol and dipentaerythritol also includes a circulating pump, a heat exchanger, and a pH meter. The inlet of the circulating pump is connected to the outlet of the formaldehyde removal vessel, the outlet of the circulating pump is connected to the material inlet of the heat exchanger, the material outlet of the heat exchanger is connected to the inlet of the pH meter, and the outlet of the pH meter is connected to the formaldehyde removal vessel.

[0008] Furthermore, the production apparatus for monopentaerythritol and dipentaerythritol also includes a first dryer and a first packaging machine, wherein the solid outlet of the first centrifuge is connected to the inlet of the first dryer, and the outlet of the first dryer is connected to the first packaging machine.

[0009] Furthermore, the liquid outlet of the second centrifuge is connected to the inlet of the evaporator.

[0010] Furthermore, the production apparatus for monopentaerythritol and dipentaerythritol also includes a condenser and a reboiler;

[0011] The gas phase outlet at the top of the hydrolysis tower is connected to the inlet of the condenser, and the outlet of the condenser is connected to the reflux port of the hydrolysis tower.

[0012] The hydrolysis tower has a bottom vessel, the inlet of the reboiler is connected to the lower end of the vessel, and the outlet of the reboiler is connected to the upper end of the vessel.

[0013] Furthermore, the production apparatus for monopentaerythritol and dipentaerythritol also includes a second dryer and a second packaging machine. The solid outlet of the third centrifuge is connected to the inlet of the second dryer, and the outlet of the second dryer is connected to the second packaging machine.

[0014] Furthermore, the liquid outlet of the third centrifuge is connected to the first dissolving vessel.

[0015] Furthermore, the production apparatus for monopentaerythritol and dipentaerythritol also includes a third dryer and a third packaging machine. The solid outlet of the fourth centrifuge is connected to the inlet of the third dryer, and the outlet of the third dryer is connected to the third packaging machine.

[0016] Furthermore, the liquid outlet of the fourth centrifuge is connected to the inlet of the second washer.

[0017] Furthermore, the evaporator is a multi-effect evaporator, and both the first filter press and the second filter press are plate and frame filter presses.

[0018] Using the above technical solution, formaldehyde aqueous solution is fed into the condensation reactor through the formaldehyde inlet, and alkaline solution is fed into the condensation reactor through the first alkaline inlet. The temperature in the condensation reactor is controlled to allow the formaldehyde aqueous solution and alkaline solution to react for a certain period of time. Then, acetaldehyde aqueous solution is slowly added dropwise to the condensation reactor through the acetaldehyde inlet to carry out the reaction. Formic acid is then added to the condensation reactor through the first formic acid inlet to neutralize and terminate the condensation reaction and control the pH value. After the reaction, the condensate flows from the outlet of the condensation reactor into the formaldehyde removal reactor. Alkaline solution is added to the formaldehyde removal reactor through the second alkaline inlet to control the pH value. Hydrogen peroxide is added to the formaldehyde removal reactor through the hydrogen peroxide inlet to ensure that the residual formaldehyde in the condensate in the formaldehyde removal reactor is zero. Then, formic acid is added to the formaldehyde removal reactor through the second formic acid inlet to neutralize the excess alkaline solution and control the pH value. After the reaction, the reaction solution flows from the outlet of the formaldehyde removal reactor into the evaporator for dehydration. The dehydrated reaction solution flows from the outlet of the evaporator into the first centrifuge for separation. The liquid material separated by the first centrifuge contains monopentaerythritol and dipentaerythritol. The liquid material separated by the first centrifuge will enter the first crystallization vessel from the liquid outlet of the first centrifuge for cooling and crystallization, and then enter the second centrifuge from the outlet of the first crystallization vessel for separation. The solid material separated in the second centrifuge enters the first dissolving vessel from the solid outlet of the second centrifuge. Water is added to the first dissolving vessel from the first solvent inlet to dissolve the solid material in the first dissolving vessel. Then, the solution in the first dissolving vessel enters the hydrolysis tower to hydrolyze impurities in order to remove impurities. Then, the solution enters the first decolorizing vessel from the liquid phase outlet at the bottom of the hydrolysis tower. Activated carbon is added to the first decolorizing vessel from the first activated carbon inlet. Then, the solution in the first decolorizing vessel enters the first filter press from the outlet of the first decolorizing vessel for filtration and decolorization. Then, the filtrate enters the second crystallization vessel from the outlet of the first filter press for cooling and crystallization. Then, the material in the second crystallization vessel enters the first washing vessel from the outlet of the second crystallization vessel for washing and separation. The solid material cleaned and purified in the first washing vessel is pentaerythritol, which enters the collection tank from the solid outlet of the first washing vessel and then enters the third centrifuge for solid-liquid separation. The solid material separated in the third centrifuge is pentaerythritol.Furthermore, the liquid after washing in the first washing unit contains dipentaerythritol. This washing liquid flows from the liquid outlet of the first washing unit into the second washing unit to concentrate the dipentaerythritol. The concentrated material in the second washing unit then enters the second solvent tank. Water is added to the second solvent tank through the second solvent inlet, and the material in the second solvent tank is heated. The material in the second solvent tank then flows from its outlet into the second decolorizing tank. Activated carbon is added to the second decolorizing tank through the second activated carbon inlet. The material in the second decolorizing tank then flows from its outlet into the second decolorizing tank. The liquid is filtered and decolorized in the second filter press. Then, the filtrate from the second filter press enters the third crystallization vessel from the outlet of the first filter press for cooling and crystallization. The material from the third crystallization vessel then enters the fourth centrifuge from the outlet of the third crystallization vessel for solid-liquid separation. The solid material separated in the fourth centrifuge is dipentaerythritol. Therefore, this production device can produce both monopentaerythritol and dipentaerythritol, making full use of raw materials, improving the utilization rate of raw materials, reducing the generation of by-products and waste, thereby reducing resource waste and improving economic efficiency. Attached Figure Description

[0019] Figure 1 This is a process flow diagram of the production apparatus for monopentaerythritol and dipentaerythritol according to this utility model.

[0020] In the diagram: 1. Condensation vessel; 2. Formaldehyde removal vessel; 3. Evaporator; 4. First centrifuge; 5. First crystallization vessel; 6. Second centrifuge; 7. First dissolving vessel; 8. Hydrolysis tower; 9. First decolorization vessel; 10. First filter press; 11. Second crystallization vessel; 12. First washing vessel; 13. Collection tank; 14. Third centrifuge; 15. Second washing vessel; 16. Second dissolving vessel; 17. Second decolorization vessel; 18. Second filter press; 19. Third crystallization vessel; 20. Fourth centrifuge; 21. Circulating pump; 22. Heat exchanger; 23. pH meter; 24. First dryer; 25. First packaging machine; 26. Condenser; 27. Reboiler; 28. Second dryer; 29. ​​Second packaging machine; 30. Third dryer; 31. Third packaging machine; 32. Feed pump. Detailed Implementation

[0021] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0022] like Figure 1As shown, a production apparatus for monopentaerythritol and dipentaerythritol includes a condensation kettle 1, an aldehyde removal kettle 2, an evaporator 3, a first centrifuge 4, a first crystallization kettle 5, a second centrifuge 6, a first dissolving kettle 7, a hydrolysis tower 8, a first decolorization kettle 9, a first filter press 10, a second crystallization kettle 11, a first washing device 12, a collection tank 13, a third centrifuge 14, a second washing device 15, a second dissolving kettle 16, a second decolorization kettle 17, a second filter press 18, a third crystallization kettle 19, and a fourth centrifuge 20.

[0023] The outlet of the condensation vessel 1 is connected to the inlet of the formaldehyde removal vessel 2. The outlet of the formaldehyde removal vessel 2 is connected to the inlet of the evaporator 3. The outlet of the evaporator 3 is connected to the inlet of the first centrifuge 4. The liquid outlet of the first centrifuge 4 is connected to the inlet of the first crystallization vessel 5. The outlet of the first crystallization vessel 5 is connected to the inlet of the second centrifuge 6. The solid outlet of the second centrifuge 6 is connected to the inlet of the first dissolving vessel 7. The outlet of the first dissolving vessel 7 is connected to the inlet of the hydrolysis tower 8. The liquid phase outlet at the bottom of the hydrolysis tower 8 is connected to the inlet of the first decolorization vessel 9. The outlet of the first decolorization vessel 9 is connected to the inlet of the first filter press 10. The outlet of the first filter press 10 is connected to the inlet of the second crystallization vessel 11. The outlet of the second crystallizing vessel 11 is connected to the inlet of the first washing vessel 12. The solid outlet of the first washing vessel 12 is connected to the collecting tank 13. The outlet of the collecting tank 13 is connected to the inlet of the third centrifuge 14. The liquid outlet of the first washing vessel 12 is connected to the inlet of the second washing vessel 15. The outlet of the second washing vessel 15 is connected to the inlet of the second dissolving vessel 16. The outlet of the second dissolving vessel 16 is connected to the inlet of the second decolorizing vessel 17. The outlet of the second decolorizing vessel 17 is connected to the inlet of the second filter press 18. The outlet of the second filter press 18 is connected to the inlet of the third crystallizing vessel 19. The outlet of the third crystallizing vessel 19 is connected to the inlet of the fourth centrifuge 20.

[0024] The condensation vessel 1 has a formaldehyde inlet, an acetaldehyde inlet, a first alkali inlet, and a first formic acid inlet; the formaldehyde removal vessel 2 has a hydrogen peroxide inlet, a second alkali inlet, and a second formic acid inlet; the first dissolving vessel 7 has a first solvent inlet; the first decolorizing vessel 9 has a first activated carbon inlet; the second dissolving vessel 16 has a second solvent inlet; and the second decolorizing vessel 17 has a second activated carbon inlet.

[0025] Specifically, formaldehyde aqueous solution is fed into condensation vessel 1 through the formaldehyde inlet, and alkaline solution is fed into condensation vessel 1 through the first alkaline inlet. The temperature in condensation vessel 1 is controlled to allow the formaldehyde aqueous solution and alkaline solution to react for a certain period of time. Then, acetaldehyde aqueous solution is slowly added dropwise to condensation vessel 1 through the acetaldehyde inlet to carry out the reaction. Formic acid is then added to condensation vessel 1 through the first formic acid inlet to neutralize and terminate the condensation reaction and control the pH value. After the reaction, the condensate flows from the outlet of condensation vessel 1 into formaldehyde removal vessel 2. Alkaline solution is added to formaldehyde removal vessel 2 through the second alkaline inlet to control the pH value. Hydrogen peroxide is added to formaldehyde removal vessel 2 through the hydrogen peroxide inlet to ensure that the residual formaldehyde in the condensate in formaldehyde removal vessel 2 is zero. Then, formic acid is added to formaldehyde removal vessel 2 through the second formic acid inlet to neutralize the excess alkaline solution and control the pH value. After the reaction, the reaction solution flows from the outlet of formaldehyde removal vessel 2 into evaporator 3 for dehydration. The dehydrated reaction solution flows from the outlet of evaporator 3 into the first centrifuge 4 for separation. The liquid material separated by the first centrifuge 4 contains monopentaerythritol and dipentaerythritol. This liquid material enters the first crystallization vessel 5 from the liquid outlet of the first centrifuge 4 for cooling and crystallization, and then enters the second centrifuge 6 from the outlet of the first crystallization vessel 5 for further separation. The solid material separated by the second centrifuge 6 enters the first solvent vessel 7 from the solid outlet of the second centrifuge 6. Water is added to the first solvent vessel 7 from the first solvent inlet to dissolve the solid material. The solution in the first solvent vessel 7 then enters the hydrolysis tower 8 to hydrolyze impurities and remove them. The solution then enters the first decolorization vessel 9 from the liquid phase outlet at the bottom of the hydrolysis tower 8. Activated carbon is added to the first decolorization vessel 9 from the first activated carbon inlet, and the solution in the first decolorization vessel 9 exits from the outlet of the first decolorization vessel 9. The material enters the first filter press 10 for filtration and decolorization. The filtrate then enters the second crystallization vessel 11 from the outlet of the first filter press 10 for cooling and crystallization. The material in the second crystallization vessel 11 then enters the first washer 12 from the outlet of the second crystallization vessel 11 for washing and separation. The solid material after washing and purification in the first washer 12 is pentaerythritol, which enters the collection tank 13 from the solid outlet of the first washer 12 and then enters the third centrifuge 14 for solid-liquid separation. The solid material separated in the third centrifuge 14 is pentaerythritol.Furthermore, the liquid washed in the first washer 12 contains dipentaerythritol. This washed liquid flows from the liquid outlet of the first washer 12 into the second washer 15 to concentrate the dipentaerythritol. The concentrated material in the second washer 15 then enters the second solvent tank 16. Water is added to the second solvent tank 16 through the second solvent inlet, and the material in the second solvent tank 16 is heated. The material in the second solvent tank 16 then flows from the outlet of the second solvent tank 16 into the second decolorizing tank 17. Activated carbon is added to the second decolorizing tank 17 through the second activated carbon inlet. The material in the second decolorizing tank 17 then flows from the outlet of the second decolorizing tank 17 into the second decolorizing tank 17. The filtrate from filter 7 enters the second filter press 18 for filtration and decolorization. The filtrate from the second filter press 18 then enters the third crystallization vessel 19 from the outlet of the first filter press 10 for cooling and crystallization. The material from the third crystallization vessel 19 then enters the fourth centrifuge 20 from the outlet of the third crystallization vessel 19 for solid-liquid separation. The solid material separated in the fourth centrifuge 20 is dipentaerythritol. Therefore, this production unit can produce both monopentaerythritol and dipentaerythritol, making full use of raw materials, improving raw material utilization, reducing by-products and waste, thereby reducing resource waste and improving economic efficiency. The alkaline solution can be a calcium oxide solution.

[0026] like Figure 1 As shown, the production apparatus for monopentaerythritol and dipentaerythritol may further include a circulating pump 21, a heat exchanger 22, and a pH meter 23. The inlet of the circulating pump 21 is connected to the outlet of the formaldehyde removal vessel 2, the outlet of the circulating pump 21 is connected to the material inlet of the heat exchanger 22, the material outlet of the heat exchanger 22 is connected to the inlet of the pH meter 23, and the outlet of the pH meter 23 is connected to the formaldehyde removal vessel 2. Specifically, the circulating pump 21 is used to pump the reaction liquid at the bottom of the formaldehyde removal vessel 2 to the upper part of the formaldehyde removal vessel 2, thereby circulating the reaction liquid in the formaldehyde removal vessel 2. The heat exchanger 22 can exchange heat with the reaction liquid to control the temperature of the reaction liquid in the formaldehyde removal vessel 2, and the pH meter 23 can detect the pH value of the reaction liquid in the formaldehyde removal vessel 2.

[0027] like Figure 1 As shown, the production apparatus for monopentaerythritol and dipentaerythritol may further include a first dryer 24 and a first packaging machine 25. The solid outlet of the first centrifuge 4 is connected to the inlet of the first dryer 24, and the outlet of the first dryer 24 is connected to the first packaging machine 25. Specifically, the solid material separated in the first centrifuge 4, which is calcium formate, enters the first dryer 24 from the solid outlet of the first centrifuge 4 for drying and then enters the first packaging machine 25 for packaging.

[0028] like Figure 1As shown, the liquid outlet of the second centrifuge 6 is connected to the inlet of the evaporator 3; specifically, the liquid separated in the second centrifuge 6 flows from the liquid outlet of the second centrifuge 6 to the inlet of the evaporator 3 and then enters the evaporator 3 for dehydration.

[0029] like Figure 1 As shown, the production apparatus for monopentaerythritol and dipentaerythritol may further include a condenser 26 and a reboiler 27.

[0030] The gas phase outlet at the top of the hydrolysis tower 8 is connected to the inlet of the condenser 26, and the outlet of the condenser 26 is connected to the reflux port of the hydrolysis tower 8.

[0031] The hydrolysis tower 8 has a bottom vessel. The inlet of the reboiler 27 is connected to the lower end of the vessel, and the outlet of the reboiler 27 is connected to the upper end of the vessel. Specifically, the gas evaporated in the hydrolysis tower 8 flows from the gas phase outlet at the top of the hydrolysis tower 8 into the condenser 26 and is condensed into liquid in the condenser 26 before flowing back to the reflux port of the hydrolysis tower 8. Furthermore, the liquid in the bottom vessel of the hydrolysis tower 8 enters the reboiler 27 for heating before flowing back to the upper end of the vessel.

[0032] like Figure 1 As shown, the production apparatus for monopentaerythritol and dipentaerythritol may further include a second dryer 28 and a second packaging machine 29. The solid outlet of the third centrifuge 14 is connected to the inlet of the second dryer 28, and the outlet of the second dryer 28 is connected to the second packaging machine 29. Specifically, the solid material separated in the third centrifuge 14, which is monopentaerythritol, will enter the second dryer 28 from the solid outlet of the third centrifuge 14 for drying and then enter the second packaging machine 29 for packaging.

[0033] like Figure 1 As shown, the liquid outlet of the third centrifuge 14 is connected to the first dissolving vessel 7; specifically, the liquid separated in the third centrifuge 14 is discharged from the liquid outlet of the third centrifuge 14 into the first dissolving vessel 7.

[0034] like Figure 1 As shown, the production apparatus for monopentaerythritol and dipentaerythritol may further include a third dryer 30 and a third packaging machine 31. The solid outlet of the fourth centrifuge 20 is connected to the inlet of the third dryer 30, and the outlet of the third dryer 30 is connected to the third packaging machine 31. Specifically, the solid material separated in the fourth centrifuge 20, which is dipentaerythritol, will enter the third dryer 30 from the solid outlet of the fourth centrifuge 20 for drying and then enter the third packaging machine 31 for packaging.

[0035] like Figure 1As shown, the liquid outlet of the fourth centrifuge 20 is connected to the inlet of the second washer 15; specifically, the liquid separated in the fourth centrifuge 20 is discharged from the liquid outlet of the fourth centrifuge 20 to the second washer 15 for further concentration.

[0036] Specifically, the evaporator 3 can be a multi-effect evaporator 3, and both the first filter press 10 and the second filter press 18 can be plate and frame filter presses.

[0037] In this embodiment, the following connections are established: the outlet of condensation vessel 1 is connected to the inlet of formaldehyde removal vessel 2; the outlet of formaldehyde removal vessel 2 is connected to the inlet of evaporator 3; the outlet of evaporator 3 is connected to the inlet of first centrifuge 4; the liquid outlet of first centrifuge 4 is connected to the inlet of first crystallization vessel 5; the outlet of first crystallization vessel 5 is connected to the inlet of second centrifuge 6; the liquid outlet of second centrifuge 6 is connected to the inlet of evaporator 3; the liquid outlet of third centrifuge 14 is connected to first dissolving vessel 7; the outlet of first dissolving vessel 7 is connected to the inlet of hydrolysis tower 8; the liquid phase outlet at the bottom of hydrolysis tower 8 is connected to the inlet of first decolorization vessel 9; and the outlet of first decolorization vessel 9 is connected to first filter press 10. Feed pumps 32 may be provided between the inlets of the first filter press 10 and the inlet of the second crystallizer 11, between the outlet of the second crystallizer 11 and the inlet of the first washer 12, between the liquid outlet of the first washer 12 and the inlet of the second washer 15, between the outlet of the second dissolving vessel 16 and the inlet of the second decolorizing vessel 17, between the outlet of the second decolorizing vessel 17 and the inlet of the second filter press 18, between the outlet of the second filter press 18 and the inlet of the third crystallizer 19, between the outlet of the third crystallizer 19 and the inlet of the fourth centrifuge 20, and between the liquid outlet of the fourth centrifuge 20 and the inlet of the second washer 15.

[0038] In summary, formaldehyde aqueous solution is fed into condensation vessel 1 through the formaldehyde inlet, and alkaline solution is fed into condensation vessel 1 through the first alkaline inlet. The temperature in condensation vessel 1 is controlled to allow the formaldehyde aqueous solution and alkaline solution to react for a certain period of time. Then, acetaldehyde aqueous solution is slowly added dropwise to condensation vessel 1 through the acetaldehyde inlet to carry out the reaction. Formic acid is then added to condensation vessel 1 through the first formic acid inlet to neutralize and terminate the condensation reaction and control the pH value. After the reaction, the condensate flows from the outlet of condensation vessel 1 into formaldehyde removal vessel 2. Alkaline solution is added to formaldehyde removal vessel 2 through the second alkaline inlet to control the pH value. Hydrogen peroxide is added to formaldehyde removal vessel 2 through the hydrogen peroxide inlet to ensure that the residual formaldehyde in the condensate in formaldehyde removal vessel 2 is zero. Then, formic acid is added to formaldehyde removal vessel 2 through the second formic acid inlet to neutralize the excess alkaline solution and control the pH value. After the reaction, the reaction solution flows from the outlet of formaldehyde removal vessel 2 into evaporator 3 for dehydration. The dehydrated reaction solution flows from the outlet of evaporator 3 into the first centrifuge 4 for separation. The liquid material separated by the first centrifuge 4 contains monopentaerythritol and dipentaerythritol. This liquid material enters the first crystallization vessel 5 from the liquid outlet of the first centrifuge 4 for cooling and crystallization, and then enters the second centrifuge 6 from the outlet of the first crystallization vessel 5 for further separation. The solid material separated by the second centrifuge 6 enters the first solvent vessel 7 from the solid outlet of the second centrifuge 6. Water is added to the first solvent vessel 7 from the first solvent inlet to dissolve the solid material. The solution in the first solvent vessel 7 then enters the hydrolysis tower 8 to hydrolyze impurities and remove them. The solution then enters the first decolorization vessel 9 from the liquid phase outlet at the bottom of the hydrolysis tower 8. Activated carbon is added to the first decolorization vessel 9 from the first activated carbon inlet, and the solution in the first decolorization vessel 9 exits from the outlet of the first decolorization vessel 9. The material enters the first filter press 10 for filtration and decolorization. The filtrate then enters the second crystallization vessel 11 from the outlet of the first filter press 10 for cooling and crystallization. The material in the second crystallization vessel 11 then enters the first washer 12 from the outlet of the second crystallization vessel 11 for washing and separation. The solid material after washing and purification in the first washer 12 is pentaerythritol, which enters the collection tank 13 from the solid outlet of the first washer 12 and then enters the third centrifuge 14 for solid-liquid separation. The solid material separated in the third centrifuge 14 is pentaerythritol.Furthermore, the liquid washed in the first washer 12 contains dipentaerythritol. This washed liquid flows from the liquid outlet of the first washer 12 into the second washer 15 to concentrate the dipentaerythritol. The concentrated material in the second washer 15 then enters the second solvent tank 16. Water is added to the second solvent tank 16 through the second solvent inlet, and the material in the second solvent tank 16 is heated. The material in the second solvent tank 16 then flows from the outlet of the second solvent tank 16 into the second decolorizing tank 17. Activated carbon is added to the second decolorizing tank 17 through the second activated carbon inlet. The material in the second decolorizing tank 17 then flows from the outlet of the second decolorizing tank 17 into the second decolorizing tank 17. The filtrate from filter 7 enters the second filter press 18 for filtration and decolorization. Then, the filtrate from the second filter press 18 enters the third crystallization vessel 19 from the outlet of the first filter press 10 for cooling and crystallization. The material from the third crystallization vessel 19 then enters the fourth centrifuge 20 from the outlet of the third crystallization vessel 19 for solid-liquid separation. The solid material separated in the fourth centrifuge 20 is dipentaerythritol. Therefore, this production device can produce both monopentaerythritol and dipentaerythritol, making full use of raw materials, improving the utilization rate of raw materials, reducing the generation of by-products and waste, thereby reducing resource waste and improving economic efficiency.

[0039] The specific embodiments described above further illustrate the technical problems, technical solutions, and beneficial effects of this utility model. It should be understood that the above descriptions are merely specific embodiments of this utility model and are not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An apparatus for producing mono- and di-pentaerythritol, characterized by comprising: It includes a condensation kettle, a formaldehyde removal kettle, an evaporator, a first centrifuge, a first crystallization kettle, a second centrifuge, a first dissolving kettle, a hydrolysis tower, a first decolorization kettle, a first filter press, a second crystallization kettle, a first washing device, a collection tank, a third centrifuge, a second washing device, a second dissolving kettle, a second decolorization kettle, a second filter press, a third crystallization kettle, and a fourth centrifuge; The outlet of the condensation vessel is connected to the inlet of the formaldehyde removal vessel, the outlet of the formaldehyde removal vessel is connected to the inlet of the evaporator, the outlet of the evaporator is connected to the inlet of the first centrifuge, the liquid outlet of the first centrifuge is connected to the inlet of the first crystallization vessel, the outlet of the first crystallization vessel is connected to the inlet of the second centrifuge, the solid outlet of the second centrifuge is connected to the inlet of the first solvent vessel, the outlet of the first solvent vessel is connected to the inlet of the hydrolysis tower, the liquid phase outlet at the bottom of the hydrolysis tower is connected to the inlet of the first decolorization vessel, the outlet of the first decolorization vessel is connected to the inlet of the first filter press, and the outlet of the first filter press is connected to the... The inlet of the second crystallization vessel is connected to the outlet of the second crystallization vessel, which is connected to the inlet of the first washing vessel. The solid outlet of the first washing vessel is connected to the collection tank, and the outlet of the collection tank is connected to the inlet of the third centrifuge. The liquid outlet of the first washing vessel is connected to the inlet of the second washing vessel, and the outlet of the second washing vessel is connected to the inlet of the second dissolving vessel. The outlet of the second dissolving vessel is connected to the inlet of the second decolorizing vessel, and the outlet of the second decolorizing vessel is connected to the inlet of the second filter press. The outlet of the second filter press is connected to the inlet of the third crystallization vessel, and the outlet of the third crystallization vessel is connected to the inlet of the fourth centrifuge. The condensation vessel has a formaldehyde inlet, an acetaldehyde inlet, a first alkali inlet, and a first formic acid inlet; the formaldehyde removal vessel has a hydrogen peroxide inlet, a second alkali inlet, and a second formic acid inlet; the first dissolving vessel has a first solvent inlet; the first decolorizing vessel has a first activated carbon inlet; the second dissolving vessel has a second solvent inlet; and the second decolorizing vessel has a second activated carbon inlet.

2. The production apparatus of mono- and di-pentaerythritol according to claim 1, characterized by, It also includes a circulating pump, a heat exchanger, and a pH meter. The inlet of the circulating pump is connected to the outlet of the formaldehyde removal vessel, the outlet of the circulating pump is connected to the material inlet of the heat exchanger, the material outlet of the heat exchanger is connected to the inlet of the pH meter, and the outlet of the pH meter is connected to the formaldehyde removal vessel.

3. The production apparatus of mono- and di-pentaerythritol according to claim 1, characterized by, It also includes a first dryer and a first packaging machine, wherein the solid outlet of the first centrifuge is connected to the inlet of the first dryer, and the outlet of the first dryer is connected to the first packaging machine.

4. The production apparatus of mono- and di-pentaerythritol according to claim 1, characterized by, The liquid outlet of the second centrifuge is connected to the inlet of the evaporator.

5. The production apparatus of mono- and di-pentaerythritol according to claim 1, characterized by, It also includes condensers and reboilers; The gas phase outlet at the top of the hydrolysis tower is connected to the inlet of the condenser, and the outlet of the condenser is connected to the reflux port of the hydrolysis tower. The hydrolysis tower has a bottom vessel, the inlet of the reboiler is connected to the lower end of the vessel, and the outlet of the reboiler is connected to the upper end of the vessel.

6. The production apparatus of mono- and di-pentaerythritol according to claim 1, characterized by, It also includes a second dryer and a second packaging machine. The solid outlet of the third centrifuge is connected to the inlet of the second dryer, and the outlet of the second dryer is connected to the second packaging machine.

7. The production apparatus of mono- and di-pentaerythritol according to claim 1, characterized by, The liquid outlet of the third centrifuge is connected to the first dissolving vessel.

8. The production apparatus of mono- and di-pentaerythritol according to claim 1, characterized by, It also includes a third dryer and a third packaging machine. The solid outlet of the fourth centrifuge is connected to the inlet of the third dryer, and the outlet of the third dryer is connected to the third packaging machine.

9. The production apparatus of mono- and di-pentaerythritol according to claim 1, characterized by, The liquid outlet of the fourth centrifuge is connected to the inlet of the second washer.

10. The production apparatus of mono- and di-pentaerythritol according to claim 1, characterized by, The evaporator is a multi-effect evaporator, and both the first filter press and the second filter press are plate and frame filter presses.

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