Description
Key words: chlorinated polyethylene (CPE) dryer, CPE drying production line, CPE special university boiling dryer
Classification: chemical engineering industry
Case overview: this production line uses combined dryer (multiple models) to dry and cool CPE materials, which can dry and cool CPE with 50% initial moisture to the required technical requirements. In terms of technical points: the design of large air volume and high pressure blast, high wind bottom pressure induced air technology; the circular main structure design of drying bed; combined air distribution structure design; DCS centralized control technology and so on.
Material overview:
The product of partial hydrogen atom substituted by chlorine atom on the molecular chain of polyethylene. The mass percentage of chlorine is generally 25% ~ 45%, which has good heat aging and oil resistance.
Shandong Borun Industrial Co., Ltd. is a large edible alcohol production enterprise in Shandong Province and a key agricultural leading enterprise in Weifang City. The CPE project with an annual output of 20000 tons of chlorinated polyethylene invested by the company has won the trust of customers in terms of product performance and enterprise reputation after a lot of investigation and comparison with domestic drying equipment manufacturers. The equipment recommended by our company for Borun company is one yfg-4000 circular fluidized bed, one dsh-5000 double screw cone mixer and one set of large bag filter.
At present, water phase process and other processes are mostly used to produce CPE in China. Our company has successfully developed 4 sets of CPE units, which all adopt advanced hydrochloric acid phase method technology. Through continuous innovation and development, CPE can react, clean and directly dry in high concentration hydrochloric acid solution, and neutralization process is omitted, so that the product has no salt, higher purity and whiteness, by-product hydrochloric acid can be recycled and no waste acid is discharged Put it.
Advanced technology makes CPE products have better elasticity and rubber feeling, which can give the products a fine and flexible appearance, especially suitable for high-end applications such as plastics and rubber.
1、 Design conditions of drying equipment for chlorinated polyethylene
1. Material conditions
Material name: CPE
Initial moisture: 10% - 30 (based on 30%)
Final moisture: < 0.3%
Feeding amount: 6000kg / batch
Bulk specific gravity of wet material: 0.56g/cm2
Raw material temperature: 15 ℃ (designed according to room temperature)
Product temperature: 35-40 ℃
2. Process conditions
Drying method: circular fluidized bed
Contact mode of material and hot air: direct type
Heat source and heating mode: steam heating (0.6-0.7mpa, 120 ℃)
Drying inlet air temperature: 110 ~ 120 ℃ (120 ℃ for design)
Drying exhaust temperature: ≤ 75 ℃ (75 ℃ for design)
Product discharge mode: circular fluidized bed host
Dust removal method: cyclone separator
3. Design meteorological conditions
Atmospheric pressure: 101.325kpa
Ambient temperature: 15 ℃
Relative humidity: 80%
4. Public works
4.1 power supply
Power supply: 380V, 3-phase, 50 Hz
Power: 324.1kw
2、 Special drying equipment for chlorinated polyethylene, dryer equipment principle and process flow description:
1. Process flow:
CPE wet materials are fed into the dryer under the action of positive pressure air supply, and the filtered fresh air enters the heater for heating, and the heated hot air is blown into the dryer from the bottom of the dryer. The materials in the dryer are boiling under the action of stirring and hot air until the end of drying. The dried CPE materials are discharged into the hopper through the dryer discharge valve, and then into the dried CPE particle bin through the hopper discharge valve. The fine materials enter the grinding and grinding process before entering the filter separator. The CPE powder is transported to the packaging CPE silo by the process air through the discharge valve. During the drying process, CPE powder carried by waste gas is separated by cyclone separator and blown back to the dryer by compressed air. Hydrogen chloride in tail gas is neutralized and absorbed in the scrubber. The washing water is collected at the bottom of the scrubber and returned to the washing water tank. After adding alkali liquor regularly, the power is provided by the washing water pump for power circulation. The surplus water overflows to the wastewater treatment station. The waste gas formed in the process of grinding and crushing materials is drained by the induced draft fan of the filter separator, and the tail gas is ensured to meet the standard.
2. Basic principle:
The purified hot air is blown from the bottom of the porous flower plate of the dryer. Under the action of stirring, it is fully in contact with the material, and the material in the dryer is boiling. CPE material particles float up and down in hot air, collide and mix with each other. Mass transfer and heat transfer are carried out between gas and solid, so as to fully volatilize moisture and residual hydrogen chloride gas in the material, so as to achieve the purpose of drying.
3. Actual design process:
According to the material characteristics and the results of discussion between both parties, the air conveying equipment and the boiling drying equipment are selected for gap connection. After centrifugation, the materials are sent to the air inlet by the positive pressure fan, and the air of the materials is sent to the boiling drying bed by the fan; the two sets of equipment have a feeding port, and the feeding branch pipe is controlled by the pneumatic control valve, and the drying air supply fan and induced draft fan are opened at the same time of feeding, so that the materials can form fluidized drying under the action of high-speed air flow. The drying of materials is completed under the fluidization of a certain time. After drying, the discharge door is opened, and the materials are discharged from the main engine through wind power. Due to the centrifugal dehydration of materials, the company considers that the materials form agglomerations under the action of centrifugation. Therefore, when conveying materials, the materials will form positive pressure transmission through the fan, so that the materials can achieve the crushing effect. Cyclone separator is used for dust removal of the equipment, and tail gas is collected and purified by foam dust collector to ensure the use effect.
Classification: chemical engineering industry
Case overview: this production line uses combined dryer (multiple models) to dry and cool CPE materials, which can dry and cool CPE with 50% initial moisture to the required technical requirements. In terms of technical points: the design of large air volume and high pressure blast, high wind bottom pressure induced air technology; the circular main structure design of drying bed; combined air distribution structure design; DCS centralized control technology and so on.
Material overview:
The product of partial hydrogen atom substituted by chlorine atom on the molecular chain of polyethylene. The mass percentage of chlorine is generally 25% ~ 45%, which has good heat aging and oil resistance.
Shandong Borun Industrial Co., Ltd. is a large edible alcohol production enterprise in Shandong Province and a key agricultural leading enterprise in Weifang City. The CPE project with an annual output of 20000 tons of chlorinated polyethylene invested by the company has won the trust of customers in terms of product performance and enterprise reputation after a lot of investigation and comparison with domestic drying equipment manufacturers. The equipment recommended by our company for Borun company is one yfg-4000 circular fluidized bed, one dsh-5000 double screw cone mixer and one set of large bag filter.
At present, water phase process and other processes are mostly used to produce CPE in China. Our company has successfully developed 4 sets of CPE units, which all adopt advanced hydrochloric acid phase method technology. Through continuous innovation and development, CPE can react, clean and directly dry in high concentration hydrochloric acid solution, and neutralization process is omitted, so that the product has no salt, higher purity and whiteness, by-product hydrochloric acid can be recycled and no waste acid is discharged Put it.
Advanced technology makes CPE products have better elasticity and rubber feeling, which can give the products a fine and flexible appearance, especially suitable for high-end applications such as plastics and rubber.
1、 Design conditions of drying equipment for chlorinated polyethylene
1. Material conditions
Material name: CPE
Initial moisture: 10% - 30 (based on 30%)
Final moisture: < 0.3%
Feeding amount: 6000kg / batch
Bulk specific gravity of wet material: 0.56g/cm2
Raw material temperature: 15 ℃ (designed according to room temperature)
Product temperature: 35-40 ℃
2. Process conditions
Drying method: circular fluidized bed
Contact mode of material and hot air: direct type
Heat source and heating mode: steam heating (0.6-0.7mpa, 120 ℃)
Drying inlet air temperature: 110 ~ 120 ℃ (120 ℃ for design)
Drying exhaust temperature: ≤ 75 ℃ (75 ℃ for design)
Product discharge mode: circular fluidized bed host
Dust removal method: cyclone separator
3. Design meteorological conditions
Atmospheric pressure: 101.325kpa
Ambient temperature: 15 ℃
Relative humidity: 80%
4. Public works
4.1 power supply
Power supply: 380V, 3-phase, 50 Hz
Power: 324.1kw
2、 Special drying equipment for chlorinated polyethylene, dryer equipment principle and process flow description:
1. Process flow:
CPE wet materials are fed into the dryer under the action of positive pressure air supply, and the filtered fresh air enters the heater for heating, and the heated hot air is blown into the dryer from the bottom of the dryer. The materials in the dryer are boiling under the action of stirring and hot air until the end of drying. The dried CPE materials are discharged into the hopper through the dryer discharge valve, and then into the dried CPE particle bin through the hopper discharge valve. The fine materials enter the grinding and grinding process before entering the filter separator. The CPE powder is transported to the packaging CPE silo by the process air through the discharge valve. During the drying process, CPE powder carried by waste gas is separated by cyclone separator and blown back to the dryer by compressed air. Hydrogen chloride in tail gas is neutralized and absorbed in the scrubber. The washing water is collected at the bottom of the scrubber and returned to the washing water tank. After adding alkali liquor regularly, the power is provided by the washing water pump for power circulation. The surplus water overflows to the wastewater treatment station. The waste gas formed in the process of grinding and crushing materials is drained by the induced draft fan of the filter separator, and the tail gas is ensured to meet the standard.
2. Basic principle:
The purified hot air is blown from the bottom of the porous flower plate of the dryer. Under the action of stirring, it is fully in contact with the material, and the material in the dryer is boiling. CPE material particles float up and down in hot air, collide and mix with each other. Mass transfer and heat transfer are carried out between gas and solid, so as to fully volatilize moisture and residual hydrogen chloride gas in the material, so as to achieve the purpose of drying.
3. Actual design process:
According to the material characteristics and the results of discussion between both parties, the air conveying equipment and the boiling drying equipment are selected for gap connection. After centrifugation, the materials are sent to the air inlet by the positive pressure fan, and the air of the materials is sent to the boiling drying bed by the fan; the two sets of equipment have a feeding port, and the feeding branch pipe is controlled by the pneumatic control valve, and the drying air supply fan and induced draft fan are opened at the same time of feeding, so that the materials can form fluidized drying under the action of high-speed air flow. The drying of materials is completed under the fluidization of a certain time. After drying, the discharge door is opened, and the materials are discharged from the main engine through wind power. Due to the centrifugal dehydration of materials, the company considers that the materials form agglomerations under the action of centrifugation. Therefore, when conveying materials, the materials will form positive pressure transmission through the fan, so that the materials can achieve the crushing effect. Cyclone separator is used for dust removal of the equipment, and tail gas is collected and purified by foam dust collector to ensure the use effect.
