Cooling and trapping device for producing p-phenylene diisocyanate

Abstract

The utility model relates to the technical field of chemical equipment, in particular to a cooling and trapping device for producing p-phenylene diisocyanate, which comprises a distillation kettle, a fraction collecting pipe is arranged at the upper part of the distillation kettle, and a condenser, a gas-liquid separator and a first trap are sequentially arranged on a pipeline of the fraction collecting pipe; a first liquid separation baffle plate, a second liquid separation baffle plate and a third liquid separation baffle plate are sequentially arranged on the fraction collection pipe behind the first trap, liquid guide branches are respectively arranged at the first liquid separation baffle plate and the third liquid separation baffle plate, and the liquid guide branches are communicated to a side receiving kettle; the third liquid separation baffle is communicated to a second catcher, a powder outlet in the bottom of the second catcher is communicated to the first collecting tank, a gas outlet in the top of the second catcher is communicated to a dust removal tank, and a powder outlet in the bottom of the dust removal tank is communicated to the second collecting tank. According to the utility model, the production process is simple, the distilled materials can be effectively separated and captured, the product yield is increased, and the distillation efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of chemical equipment technology, and in particular to a cooling and collection device for the production of terephthalic diisocyanate. Background Technology

[0002] terephthalic diisocyanate (PPDI) is an important organic compound widely used in the production of polyurethane materials, particularly in high-performance coatings, adhesives, and elastomers. With China's rapid economic development and increasing industrial demand, the PPDI industry in China is experiencing strong growth.

[0003] PPDI production primarily employs distillation purification. However, due to the inherent physical properties of the material, sublimation during distillation can easily lead to blockages in the distillation column, affecting product quality and production efficiency. Increasing the system pipe diameter to prevent blockages can result in increased material loss and reduced yield. Therefore, addressing these shortcomings is crucial in actual production. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a cooling and collection device for the production of terephthalic diisocyanate, which is simple in production process, can effectively separate and collect the distilled material, increase the product yield and improve the distillation efficiency, thus addressing the shortcomings of the existing technology.

[0005] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0006] A cooling and trapping device for the production of terephthalic diisocyanate includes a distillation kettle, a fraction collection pipe at the top of the distillation kettle, a condenser, a gas-liquid separator, and a first trap sequentially arranged on the fraction collection pipe; a first liquid separating baffle, a second liquid separating baffle, and a third liquid separating baffle sequentially arranged on the fraction collection pipe after the first trap, wherein the first liquid separating baffle and the third liquid separating baffle are respectively provided with liquid guiding branches, which are connected to a side receiving kettle; the fraction collection pipe after the third liquid separating baffle is connected to the feed inlet of the second trap, the powder outlet at the bottom of the second trap is connected to the first collection tank through a pipe and a valve, the gas outlet at the top of the second trap is connected to a dust removal tank through a pipe, and the powder outlet at the bottom of the dust removal tank is connected to the second collection tank through a pipe and a valve.

[0007] Preferably, the condenser is a condenser tube equipped with a temperature-controlled cooling jacket. It was custom-made from Jiaxing Dikent Chemical Machinery Co., Ltd.

[0008] Preferably, the gas-liquid separator has a hollow flow divider plate in the middle, with a distance between the bottom of the flow divider plate and the bottom of the fraction collection pipe. The upper part of the flow divider plate has several evenly distributed vent holes. The flow divider plate has a warm water inlet and a warm water outlet, which are respectively connected to an external warm water supply device and a warm water collection device via pipes. Gas enters the rear of the pipe through the vent holes, and liquid flows through the gap between the bottom of the flow divider plate and the bottom of the fraction collection pipe.

[0009] Preferably, both the first and second traps are slug flow traps. The slug flow trap has a closed outer shell, inside which are multiple parallel condenser tubes. The manufacturer is Jiaxing Dikent Chemical Machinery Co., Ltd.

[0010] Preferably, the bottoms of the first and third separating baffles are fixed to the bottom of the fraction collecting pipe, and the tops of the baffles are spaced apart from the top of the fraction collecting pipe (to intercept and transport the liquid to the side receiving vessel); the second separating baffle is evenly provided with a number of vent holes, the top of the second separating baffle is fixed to the top of the fraction collecting pipe, and the bottom of the second separating baffle is spaced apart from the bottom of the fraction collecting pipe.

[0011] Preferably, the side-receiving vessel is equipped with a heat exchange jacket, within which a heat exchange coil is installed. The inlet and outlet of the heat exchange coil are respectively connected to a heat exchange medium supply device and a heat exchange medium collection device. The heat exchange coil is cooled when the side-receiving vessel receives material, and after material reception is completed, it is used to transport heat source material to melt the received material and then transport it to a tablet-making machine for tablet production.

[0012] Preferably, both the first and second collecting tanks are powder collecting tanks equipped with cooling jackets; the discharge port at the bottom of the first collecting tank is connected to the side receiving vessel via pipes and valves, and is also connected to the side receiving vessel; the discharge port at the bottom of the second collecting tank is connected to the second collector, the first collecting tank and the side receiving vessel in sequence via pipes and valves.

[0013] Preferably, the dust collector has a filter cloth support in the center of its body, and the filter cloth support is surrounded by filter cloth; a nitrogen backflush pipe is provided at the outlet of the dust collector. Gas from the fraction collection pipe is first filtered through the filter cloth to remove the powder. The remaining gas enters a vacuum buffer tank from the outlet of the dust collector and is then pumped away by a vacuum pump. The nitrogen backflush pipe can backflush the powder, which is then transported to a second collection tank through the powder outlet at the bottom of the filter tank.

[0014] After adopting the above technical solution, the beneficial effects of this utility model are:

[0015] This invention features a gas-liquid separator that increases cross-sectional flow rate, reduces the flow rate of sublimated materials, and enhances separation efficiency. The first collector can pre-collect the materials to be collected, improving product yield. The separating baffles are obliquely placed at both inlets of the receiving vessel, serving as a collection, guiding, and minimally catching mechanism. The side-connected receiving vessel prevents excessive gas flow, allowing sufficient time for the intercepted material to settle, thus reducing material loss. Some uncollected material enters the second collector via a pipeline for cooling and collection. Unsettled material is then filtered through a filter cloth in a dust collector. After distillation, nitrogen backflushing is activated to blow powder off the filter cloth and collect it. This filtration device increases product yield and improves distillation efficiency.

[0016] In summary, the production process of this utility model is simple, and it can effectively separate and collect the distilled materials, thereby increasing the product yield and improving the distillation efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0018] Among them, 1. Distillation kettle; 2. Fraction collection pipe; 3. Condenser; 4. Gas-liquid separator; 5. First trap; 6. First separating baffle; 7. Second separating baffle; 8. Third separating baffle; 9. Side receiving kettle; 10. Second trap; 11. First collection tank; 12. Dust removal tank; 13. Second collection tank. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0020] Example 1:

[0021] like Figure 1As shown, a cooling and trapping device for the production of terephthalic diisocyanate includes a distillation kettle 1. A fraction collection pipe 2 is provided at the top of the distillation kettle 1. A condenser 3, a gas-liquid separator 4, and a first trap 5 are sequentially arranged on the fraction collection pipe 2. A first separating baffle 6, a second separating baffle 7, and a third separating baffle 8 are sequentially arranged within the fraction collection pipe 2 after the first trap 5. The first separating baffle 6 and the third separating baffle 8 each have a liquid guiding branch (not shown). A branch connects to the side receiving vessel 9; the fraction collection pipe 2 after the third separating baffle 8 connects to the feed inlet of the second trap 10; the powder outlet (not marked) at the bottom of the second trap 10 connects to the first collection tank 11 through a pipe (not marked) and a valve (not marked); the gas outlet (not marked) at the top of the second trap 10 connects to the dust removal tank 12 through a pipe; and the powder outlet (not marked) at the bottom of the dust removal tank 12 connects to the second collection tank 13 through a pipe and a valve.

[0022] In practical applications, the crude PPDI product containing a large amount of solvent obtained from the previous process is distilled in a distillation kettle 1 under high temperature of 180°C and vacuum conditions of 100 Pa. The distilled material and steam are first condensed in a condenser 3 through a fraction collection pipe 2. The condensed material passes through a gas-liquid separator 4 and a first collector 5 in sequence. At the first separating baffle 6, the condensed liquid material is intercepted and transferred to a side receiving kettle 9. The gaseous material continues to be transported in the fraction collection pipe 2. After being separated by the second separating baffle 7, the separated liquid material is intercepted again at the third separating baffle 8 and transferred to the side receiving kettle 9. The remaining gas continues to be transported through the fraction collection pipe 2 to the second collector 10. After cooling, some powder is obtained. The uncooled material enters the dust collector 12 with the gas and is separated by a bag filter. The powder obtained in the second collector 10 and the dust collector 12 are collected in the side receiving kettle 9, thus obtaining the un-tableted terephthalic acid diisocyanate product.

[0023] The second collector 10 and subsequent sections are used to collect and recover the gaseous materials that were not collected in the previous operation, and finally transfer them to the side receiving vessel 9 for melting, and then transfer them to the tablet making machine for tableting and packaging.

[0024] It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A cooling and collection device for the production of terephthalic diisocyanate, characterized in that: The apparatus includes a distillation kettle, the upper part of which is equipped with a fraction collection pipe. A condenser, a gas-liquid separator, and a first collector are sequentially installed on the fraction collection pipe. A first liquid-distributing baffle, a second liquid-distributing baffle, and a third liquid-distributing baffle are sequentially installed on the fraction collection pipe after the first collector. Liquid-guiding branches are respectively provided at the first and third liquid-distributing baffles, and these branches connect to a side receiving vessel. The fraction collection pipe after the third liquid-distributing baffle connects to the inlet of the second collector. The powder outlet at the bottom of the second collector is connected to a first collection tank via a pipe and a valve. The gas outlet at the top of the second collector is connected to a dust removal tank via a pipe. The powder outlet at the bottom of the dust removal tank is connected to the second collection tank via a pipe and a valve.

2. The cooling and trapping apparatus for the production of terephthalic diisocyanate according to claim 1, characterized in that: The condenser is a condenser tube equipped with a temperature control jacket for cooling.

3. The cooling and trapping apparatus for the production of terephthalic diisocyanate according to claim 1, characterized in that: The gas-liquid separator has a hollow flow divider plate in the middle, and there is a distance between the bottom of the flow divider plate and the bottom of the fraction collection pipe. Several vent holes are evenly distributed on the upper part of the flow divider plate. The flow divider plate has a warm water inlet and a warm water outlet, which are respectively connected to an external warm water supply device and a warm water collection device through pipes.

4. The cooling and collecting device for the production of terephthalic diisocyanate according to claim 1, characterized in that: Both the first trap and the second trap are slug flow traps.

5. The cooling and trapping apparatus for the production of terephthalic diisocyanate according to claim 1, characterized in that: The bottoms of the first and third separating baffles are fixed to the bottom of the fraction collecting tube, and the tops of both are spaced apart from the top of the fraction collecting tube; the second separating baffle is evenly provided with several vent holes, the top of the second separating baffle is fixed to the top of the fraction collecting tube, and the bottom of the second separating baffle is spaced apart from the bottom of the fraction collecting tube.

6. The cooling and trapping apparatus for the production of terephthalic diisocyanate according to claim 1, characterized in that: The side receiving vessel is equipped with a heat exchange jacket, and a heat exchange coil is installed inside the jacket. The inlet and outlet of the heat exchange coil are respectively connected to the heat exchange medium supply device and the heat exchange medium collection device.

7. The cooling and trapping apparatus for the production of terephthalic diisocyanate according to claim 1, characterized in that: Both the first and second collection tanks are powder collection tanks equipped with cooling jackets; the discharge port at the bottom of the first collection tank is connected to the side receiving vessel via pipes and valves, and is also connected to the side receiving vessel; the discharge port at the bottom of the second collection tank is connected to the second trap, the first collection tank and the side receiving vessel in sequence via pipes and valves.

8. The cooling and collecting apparatus for the production of terephthalic diisocyanate according to claim 1, characterized in that: The dust collector has a filter cloth support in the center of its body, and the filter cloth is wrapped around the support; the dust collector is equipped with a nitrogen backflush pipe at its outlet.

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