CN201080469Y - Middle-sized chloroethylene polymerization reaction kettle - Google Patents

Abstract

The utility model relates to a medium-sized chloro-ethylene polymerizing-kettle, which comprises a driving device, a frame, a turbulence nozzle, a semi-tube jacket, a stirring shaft, an agitator, a kettle body, a semi-tube jacket and an internal cooling baffle. The driving device is connected to the lower part of the kettle body through the frame; the stirring shaft which is a cantilever shaft is connected at the back of the driving device and the lower end of the stirring shaft and the kettle body are mechanically sealed; the agitator is fixed on the stirring shaft; a terminator mouth is arranged on the kettle body; a jacket head is arranged at the lower part of the kettle body. For the medium-sized chloro-ethylene polymerizing-kettle of the utility model, the heat transmission capability of the kettle and the heat exchanging efficiency are improved, while good shape of the product particles and even distribution of molecular weight are ensured; the terminator mouth is arranged at the lower of the kettle body, ensuring the polymerization to be quickly terminated and ensuring the product quality and the kettle safety. With the combination of the above advantages and the corresponding polymerizing process, the production capacity of the utility model can reach 420 ton per cubic meter. a, therefore the utility model provides an ideal configuration for the production of polyvinyl chloride (PVC).

Description

Medium-sized vinyl chloride polymerization reactor

Technical field

The utility model relates to a medium-sized vinyl chloride polymerization reactor for producing polyvinyl chloride through a suspension method polymerization process, which belongs to the field of chemical machinery.

Background technique

Vinyl chloride polymerization reactor is the most critical equipment in the production process of polyvinyl chloride resin. With the current increase in domestic and foreign demand for polyvinyl chloride, the production scale continues to expand, and the market competition is becoming more and more fierce. On the one hand, the vinyl chloride polymerization reactor is facing On the other hand, it is necessary to continuously use new technologies to improve and innovate existing devices in order to save production costs, reduce labor intensity, increase equipment productivity, and improve product quality.

The terminator ports of traditional polymerization reactors are all set on the upper part of the kettle body. It is not easy for the terminator to disperse quickly and evenly when entering the kettle, which affects the speed of terminating the polymerization reaction, prolongs the polymerization cycle, and also affects product quality.

At present, most of the existing heat transfer in China relies on the outer surface of the kettle body, and the overall jacket of the spiral deflector and the gap half-pipe jacket are mostly used: the overall jacket of the spiral deflector has a large flow channel area and the gap between the deflector and the jacket There is a gap, the water flow rate is low, and the heat transfer effect is poor; the gap half-pipe jacket has a certain gap between each half-pipe and the adjacent half-pipe for welding, so that the heat transfer area cannot be effectively and fully utilized. Ability is clearly limited. In addition, due to structural limitations at the bottom of the kettle, the half-pipe jacket structure cannot achieve a good heat exchange effect.

At present, the commonly used small and medium-sized reactors are not equipped with a reflux condenser on the top of the kettle, and some of them obviously reflect insufficient transmission capacity, especially in the case of high cooling water temperature in summer or the production of high-grade resins, the heat of reaction will not be easily taken away. , prolong the reaction time and affect the production capacity of the reactor.

Since the mechanical seal shell of the currently used polymerization reactor is made of carbon steel, in order to avoid corrosion, oil seals are used. The disadvantage is that the leakage of sealing oil into the kettle will have a certain impact on the quality of polyvinyl chloride.

Contents of the invention

The purpose of the utility model is to provide a medium-sized vinyl chloride polymerization reactor with high heat transfer efficiency, high production intensity and stable product quality.

The technical scheme adopted by the utility model is: a medium-sized vinyl chloride polymerization reaction kettle, including a transmission device, a frame, a spoiler nozzle, a stirring shaft, a stirrer, a kettle body, a half-pipe jacket, and an internal cooling baffle, and the transmission device passes through the machine. The frame is connected to the lower part of the kettle body, the transmission device is connected with the stirring shaft, the stirring shaft is a cantilever shaft, there is a mechanical seal between the lower end of the stirring shaft and the kettle body, and the stirrer is fixed on the stirring shaft. The terminator port, the lower part of the kettle body is provided with a jacketed head.

The medium-sized vinyl chloride polymerization reaction kettle is characterized in that: the terminator port is set at the lower part of the kettle body, the jacket head is provided with a cooling water inlet and outlet, and the water inlet is equipped with a spoiler nozzle; the upper part of the kettle body is provided with an internal spray ring.

The medium-sized vinyl chloride polymerization reaction kettle is characterized in that: the internal cooling baffle is a casing structure, and the outer tube is made of carbon steel chrome-plated or stainless steel three-dimensional internal rib tube; the top of the kettle is equipped with a reflux condenser.

The medium-sized vinyl chloride polymerization reaction kettle is characterized in that: the agitator is a two-layer three-blade swept back paddle or a single-layer four-blade flat paddle, and the ratio of the blade diameter to the internal diameter of the kettle is 0.40-0.70.

The medium-sized vinyl chloride polymerization reactor is characterized in that: the material of the mechanical seal is stainless steel, and the sealing medium inside is water.

The inner wall of the medium-sized vinyl chloride polymerization reactor is treated with mechanical polishing and electrolytic polishing, and the surface roughness Ra is less than 0.08 μm.

The medium-sized vinyl chloride polymerization reaction kettle is characterized in that: an inner spray ring is installed on the top of the kettle body, and the inner spray ring is a ring pipe with small holes.

The medium-sized vinyl chloride polymerization reaction kettle is characterized in that the volume of the kettle body is 70-120 m ³ , the aspect ratio is 1.2-1.8, and the diameter is 3.5-4.5 meters.

The medium-sized vinyl chloride polymerization reaction kettle is characterized in that the volume of the kettle body is 71.5m ³ , the height-to-diameter ratio is 1.55, and the diameter is 3.81 meters.

Beneficial effects of the utility model: adopting the medium-sized vinyl chloride polymerization reaction kettle provided by the utility model effectively improves the heat transfer capacity of the kettle, adopts a half-pipe jacket overlapping structure with a straight section, and a jacket at the bottom of the kettle body The head structure not only increases the heat transfer area compared with the traditional gap-type half-pipe jacket, but also has no flow dead zone in the jacket, and the flow resistance is small; the half-pipe jacket is divided into 6 to 12 sections, which effectively reduces the temperature difference between the inlet and outlet. The heat transfer efficiency is improved; the inner cold baffle and the outer tube are made of carbon steel chrome-plated or stainless steel three-dimensional inner rib tube, which improves the heat transfer efficiency by 3 to 5 times compared with the stainless steel bare tube, and the reflux condensation at the top of the kettle with a larger heat transfer area is adopted. The mixer fully meets the heat exchange requirements of the polymerization reaction, so that the temperature change of the polymerization can be controlled at ±0.1°C to ensure that the polyvinyl chloride reaches the predetermined degree of polymerization; according to the process requirements, the agitator adopts a three-bladed back-swept paddle or a four-bladed flat paddle. Four or two internal cooling baffles form the best stirring system, which further improves the stirring efficiency and heat transfer effect, and ensures the product particle shape is good and the molecular weight distribution is uniform; the mechanical seal adopts water seal to prevent the product from being polluted by sealing oil. Affect product quality; the inner wall of the kettle is treated with mechanical polishing and electrolytic polishing, and the surface roughness Ra is less than 0.08μm. In addition, the inner spray ring installed in the kettle body makes the spraying of the anti-sticking agent more uniform and effectively prevents the polymerization reaction process. The material sticks to the kettle, so that the production can be continued without cleaning the kettle. The terminator port is located at the lower part of the kettle body, so that the polymerization reaction can be terminated quickly, ensuring the product quality and the safety of the kettle. Based on the above advantages, coupled with the corresponding polymerization process, the production strength of the vinyl chloride polymerization reactor of the utility model can reach 420t/m ³ .a, which provides an ideal configuration for the production of polyvinyl chloride.

Description of drawings

Below by embodiment, and in conjunction with accompanying drawing, the utility model is further described:

Fig. 1 is the structural representation of the utility model embodiment;

Figure 2 is a schematic diagram of the structure of the inner spray ring;

Fig. 3 is a schematic diagram of a spoiler nozzle;

Fig. 4 is the structure schematic diagram of agitator three-bladed back-swept paddle;

Fig. 5 is a schematic diagram of the structure of the four-blade flat paddle of the agitator;

Fig. 6 is a schematic diagram of the overlapping structure of the half-pipe jacket with a straight section;

Fig. 7 is the structural representation of tank top reflux condenser;

Fig. 8 is a structural schematic diagram of a stainless steel three-dimensional inner ribbed tube.

In the picture:

1 is the transmission device, 2 is the frame, 3 is the mechanical seal, 4 is the spoiler nozzle, 5 is the terminator port, 6 is the jacket head, 7 is the stirring shaft, 8 is the agitator, 9 is the kettle body, and 10 is the Half-pipe jacket, 11 is an internal cooling baffle, 12 is an internal spray ring, and 13 is a reflux condenser.

Detailed ways

Below in conjunction with accompanying drawing, concrete structure of the present utility model is described further.

The medium-sized vinyl chloride polymerization reaction kettle includes a transmission device 1 , a kettle body 9 , a mechanical seal 3 , a stirring shaft 7 and an agitator 8 . The height-to-diameter ratio of the kettle body 9 is 1.55, the volume is ^71.5m3 , and the nominal diameter is 3.81m3; The pipe jacket 10 is an overlapping structure without gaps (as shown in Figure 6). The half-pipe jacket 10 is divided into 7 sections on the cylinder body; Jacketed head 6, two sets of cooling water inlets and outlets are arranged on the jacketed head 6, and spoiler nozzles 4 are installed at the water inlet; inner cooling baffle 11 is arranged in the kettle body 9, and the inner cooling baffle 11 is a casing structure, The outer tube adopts a stainless steel three-dimensional internal rib tube; the inner upper part of the kettle body 9 is provided with an inner spray ring 12; the upper part of the kettle body 9 is provided with a kettle top reflux condenser 13. The transmission device 1 is connected to the lower part of the kettle body 9 through the frame 2. The transmission device 1 is connected with the stirring shaft 7. The stirring shaft 7 is a cantilever shaft. There is a mechanical seal 3 between the lower end of the stirring shaft 7 and the kettle body 9. The top of the stirring shaft 7 A stirrer 8 is fixed, and the stirrer is a two-layer three-bladed back-swept paddle. The ratio of the diameter of the upper blade to the inner diameter of the kettle is 0.46, and the ratio of the diameter of the lower blade to the inner diameter of the kettle is 0.5.

Before feeding, use the inner spray ring 12 to coat the wall with anti-sticking agent. When feeding, start the transmission device 1, and stir the added materials through the agitator 8 to mix the added materials evenly. When the feeding is completed, the reaction temperature is reached at the same time. During the reaction, it passes through the jacket Head 6, internal cooling baffle 11, half-pipe jacket 10, and reflux condenser 13 take away a large amount of polymerization reaction heat, maintain a polymerization temperature difference of ±0.1°C, and stop from the bottom of the kettle when the polymerization conversion rate reaches about 80%. A terminator is added to the agent port, and the terminator is quickly mixed with the material and terminates the reaction through the agitation of the agitator 8, which ensures the product quality. The reacted material is discharged through the bottom of the kettle.

Claims (9)

1. Medium-sized vinyl chloride polymerization reactor, including transmission device, frame, spoiler nozzle, half-pipe jacket, stirring shaft, agitator, kettle body, half-pipe jacket, internal cooling baffle, the transmission device is connected through the frame In the lower part of the kettle body, there is a stirring shaft connected behind the transmission device. The stirring shaft is a cantilever shaft. There is a mechanical seal between the lower end of the stirring shaft and the kettle body. A stirrer is fixed on the stirring shaft. The feature is that the kettle body is equipped with a terminator The lower part of the kettle body is provided with a jacketed head. 2. The medium-sized vinyl chloride polymerization reaction kettle as claimed in claim 1, characterized in that: the terminator port is located at the lower part of the kettle body; the jacket head is provided with a cooling water inlet and outlet, and the water inlet is equipped with a spoiler nozzle, An inner spray ring is arranged on the upper part of the kettle body. 3. The medium-sized vinyl chloride polymerization reaction kettle as claimed in claim 1, characterized in that: the internal cooling baffle is a casing structure, and the outer tube is made of carbon steel chrome-plated or stainless steel three-dimensional internal rib tube; the top of the kettle is equipped with a reflux condenser. 4. The medium-sized vinyl chloride polymerization reaction kettle as claimed in claim 1, characterized in that: the agitator is a two-layer three-blade swept back paddle or a single-layer four-blade flat paddle, and the ratio of the blade diameter to the inner diameter of the kettle is 0.40- 0.70. 5. The medium-sized vinyl chloride polymerization reactor as claimed in claim 1, characterized in that: the material of the mechanical seal is stainless steel, and the sealing medium inside is water. 6. The inner wall of the medium-sized vinyl chloride polymerization reactor according to claim 1 is treated with mechanical polishing and electrolytic polishing, and the surface roughness Ra is less than 0.08 μm. 7. The medium-sized vinyl chloride polymerization reaction kettle as claimed in claim 1, characterized in that: an inner spray ring is installed on the top of the kettle body, and the inner spray ring is a ring pipe with small holes. 8. The medium-sized vinyl chloride polymerization reaction kettle according to claim 1, characterized in that: the volume of the kettle body is 70-120m ³ , the aspect ratio is 1.2-1.8, and the diameter is 3.5-4.5 meters. 9. The medium-sized vinyl chloride polymerization reaction kettle as claimed in claim 1, characterized in that: the volume of the kettle body is 71.5m ³ , the height-to-diameter ratio is 1.55, and the diameter is 3.81 meters.

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