[0035] In order to better understand the technical solution of the present invention, the present invention will be further described in detail below for the technical solution of the present invention. This combined technical system embodiment is suitable for resin removal of the polypropylene device for a certain amount of 25,000 tons / annual phase polypropylene devices, and the combined process system embodiments are met. figure 1 , figure 2.
[0036] In the current mainstream polypropylene process analysis and top air chromatography, the characteristic components of polypropylene powder volatilization and odor are mainly micro-propylene oligomers produced in the process of propylene polymerization, such as isomer. C6, C9 and C12 alkane components. In addition to the hexane raw material, the addition of the portion C6 component, the addition of the propylene raw material and the auxiliary agent does not be brought into components such as isomerization C9 and C12 alkanes, which are generated in the production device while The boiling point is higher than the difficulty; the "off-air" method is simply unable to achieve a good degassing effect, thus causing a large number of C9 and C12 components to remain in the product, affecting the odor and volatilization of polypropylene products. share. The "steam steaming bed process law", product VOCS and odor have guarantees, but more equipment, complex process, large investment, high energy consumption, three waste emissions, and large impacts.
[0037] The present invention provides a combination of polyolefin resin removal of VOCs and odor, and the polypropylene resin treated by combining techniques is effectively removed by VOCs and reduces product odor, and the odor of the polypropylene resin is reduced to satisfying the vehicle material requirements. The odor rating requirement.
[0038] The technical solution of the present invention is to pass a series of removal of VOCS and odor process: the process of sequentially passing the polypropylene resin by the following steps: figure 2 As shown, the hydrocarbons and polypropylene powdered materials that are entrained in the polypropylene powder discharged from the reactor is separated by the expanded bag filter, and the polypropylene powder discharged is separated; and then the powder dryer is then sent to the adsorbed VOCS2; powder Enter the degasser, purge the VOCs and inactivate the residual catalyst 3 by hot moisturizing nitrogen; fuse the polypropylene powder into the extruder, the polypropylene powder is melted in the extruder, in the squeezing machine The exhaust segment is provided with a vacuum exhaust device, and the residual VOCs remaining in the melt polypropylene 4, the process of removing the VOCs and odor of the present invention, the flow design is unique, simple operation, environmental protection, can residue in polypropylene resin The VOCs removal, the odor is lowered, and it is fully able to meet the odor demand of the downstream high-end guests to polypropylene.
[0039] The combination of the present invention is specifically described below:
[0040] (1) Expanded bag filter low pressure VOCS
[0041] The expansive bag filter is a larger cylindrical bag filtration device. The equipment has a total of 3 main pipes. The material inlet is located in the middle of the device. The line can be interposed to the centerline position of the device, and the gas outlet is located at the top of the device, solid The powder outlet is located at the bottom of the apparatus, and the bottom of the device is provided to a tapered, preventing the powder accumulation, and the outside is required to be provided to prevent gas condensation. A filter bag having an accuracy of 2 microns is installed on the upper portion of the device, and the total filter area needs to meet the flow requirements of low pressure gases. The top of the filter bag is provided with a pulsed anti-blowing, which is used to reflect the fine powder adhered to the filter bag to prevent clogging.
[0042] The powder discharged from the reactor 1 is delivered to the expansion bag filter by pressure; the filter is mounted on top of the powder dryer, the pressure is maintained at 20kpag, the low pressure in the expanded bag filter helps the powder to devolatize, remove Most of the hydrocarbons contained in the voids between the powder air pores and the particles (the residence time in the expanded bag filter is not sufficient to remove dissolved in the powder). The lower portion of the expansion bag filter is almost empty, and the powder is rotated into the powder dryer by an expanded bag filter. The circulating gas in the expanded bag filter is compressed to the reactor pressure, and the reaction system is returned.
[0043] (2) Powder heater, powder heating, further removing adsorbed VOCs
[0044] The powder heater is a cylindrical horizontal heating device with stirring shaft, and the upper end of the apparatus is provided with a top feed opening and bottom discharge port, as well as an attachment to the exhaust vent. It is mainly composed of a hot shaft, fuselage, end plate, upper cover and transmission system, and the body with a hollow jacket, and the device is driven by a motor. The blade dryer uses steam as a heat source, and the hollow hot shaft and hollow jacket of the dryer 2 are in operation, and the material is heated and dried by the mill wall. At the same time, the material moves toward the mouthward with the agitation of the hollow hot shaft.
[0045] The powder from the expanded bag filter is discharged into the powder heater by means of gravity, and the powder of the heater is turned into a stirrer, the jacket heating medium heats the powder temperature to 90-120 ° C, powder The VOCs contained in VOCs were removed. At the same time, a hot nitrogen gas heating 120 to 125 ° C is treated with a gas gauze to take away from the VOCS that carries removed. The discharge gas of the powder dryer is filtered through the bag filter, and the membrane recovery system or other exhaust gas recovery system is subjected to recycling.
[0046] (3) Degas removal of VOCS and catalyst inactivation
[0047] The degassing warehouse 3 is a cylindrical silo having a diameter of about 5.4m. The bottom is a tapered. The device has a total of 3 main interfaces. The top is provided with a powder inlet and exhaust gas outlet, and a powder outlet is provided at the bottom of the cone. . The anti-blowing gas enters the degasser from the bottom of the straight section, and the bottom of the silo is provided with a backbrow body distribution inner member, and the anti-blowing gas is divided into a plurality of annular airflow, which is used to keep the powder uniform flow, anti-blowing It is necessary to heat, need to be provided with a heater or the like.
[0048] The powder from the powder heater is from the rotating valve to the degasser; the degassed position is from about 2-4 hours of the powder residence time of about 2-4 hours, and there are two main functions: further The hydrocarbons in the flue gas gap are removed, and the residual catalyst in the powder is deactivated, and the inactivation is mainly achieved by contacting the powder containing water ("Wet" nitrogen) purge. The bottom of the degasser is provided with a hot and humid nitrogen purge line, nitrogen and a small amount of deactivated steam in a certain proportion. After heating, it enters the degasser from the bottom after heating, and the gas is sufficiently dispersed and purged by the dispersed injection port. The top of the air warehouse is discharged; the powder is entered from the top of the degassing position, flows to the bottom in the form of a piston stream and discharges from the bottom. The powder in the degasser is in the process of flowing, and the hot nitrogen gas and the powder are in contact, and the deactivation of the residual catalyst in the powder is achieved.
[0049] Taking into account the piston flow effect of the inside of the degasser, the degassed position needs to be sufficiently polished, and the bottom nitrogen injection port also needs to adopt a special tapered dispenser and nozzle. 1200 nm of thermoset flow 3/ h, ensure that the purge effect prevents the gas volume from excessive causes a poor state such as the internal nitrogen, and breaks the piston flow effect of the powder in the degasser. The purge nitrogen is heated to 115 ° C in the purge nitrogen heater, followed by mixing with the vapor in a water-nitrogen weight ratio of 0.002 to 0.004, and the hot nitrogen mixture enters the degasser through the bottom tapered dispenser and other nozzles. The water branch "kill" catalyst and the residual chloride reaction forms hydrochloric acid (HCl). Nitrogen plays a stripping gas to promote removal of hydrocarbons in powder. Since the HCl generates corrosiveness when it encounters moisture, the degassed position should be made by stainless steel, and the temperature should be controlled in the operation of the wet nitrogen dew point at not higher than -7 ° C, and the corrosion of the off-air bin is reduced. The off-activity powder is discharged from the bottom of the degassing position by the degassing boy, and then pneumatic from the powder delivery system to the extruder powder feed hopper. Renewal discharge gas is processed after the film recovery system or other exhaust gas recovery system.
[0050] (4) Extruder cylinder vacuum exhaust in the granulation process
[0051] The extruder 4 is a screw mixing apparatus that mixes, squeezes, melts, and cuts the powder. The screw length is usually 3 m or more. The outside of the screw is wrapped by a cylinder, and the cylinder is in contact with the screw, and the powder is in the cavity. In vivo is delivered and handled. The cylinder is a segment detachable and vacuum exhaust equipment is mounted on a certain cylinder downstream.
[0052] The vacuum exhaust device is provided with an exhaust port on the middle and downstream position of the extruded granulator 8, and the exhaust port is connected to the vacuum pump inlet, maintains the low pressure state of the exhaust region, and the gas extrapolate enters a buffer can. Condensation separation, discharge after condensate treatment, the exhaust gas enters the torch system.
[0053] The extruder is provided with an exhaust hole in the cylinder and subsequently configures the volatile removal system. Through the change in the structure of the screw, the reverse kneading element is provided on the exhaust hole to form a high pressure zone, and the seal melt is to be sealed, and the large pitch is provided at the pondalk to form a low pressure zone to form a low pressure zone, reduce the screw guide. Fullness of materials, to facilitate increasing exhaust, minimize resin fusion, resulting in discharge system blockage
[0054] The extruder generated by the resin product produced during the granulation stage of the extrusion process into the buffer tank through the exhaust hole, and then enters the heat exchanger, which is condensed to the gas-liquid separation under cooling water, and the condensate is processed. Row. The gas phase component enters the torch gas under vacuum pump.
[0055] The polypropylene resin from the polypropylene resin in the present invention is sequential, and the order is not allowed to replace the order, in addition to the first step, the other three can select two or two combinations, and the equity protection points of the present invention.
