Summary of the invention
Order of the present invention is exactly for overcoming above-mentioned the deficiencies in the prior art, a kind of thermo-efficiency height that has is provided, scale is big, the chlorinated polyethylene drying process of advantages such as system stability is reliable, to improving chlorinatedpolyethylene output, reduce the difficulty of operations and maintenance, guarantee quality product, the security of raising system has good effect.
For achieving the above object, the present invention has adopted following technical scheme:
A kind of chlorinated polyethylene drying process, it is that thermal source carries out two-stage drying at least with the warm air, its processing step is,
1) one-level drying: wet stock is sent into pneumatic drier (14), fully contacts with the high temperature drying air that enters pneumatic drier (14), finishes preliminarily dried, goes into fluidisation bed dryer (8), the tail gas emptying of purification by the dust removal installation dedusting is laggard then;
2) secondary drying: after the dried material of first-stage preliminary joins fluid bed dryer (8), with the high temperature drying air mixed that enters fluid bed dryer (8), make an interior material keep stable fluidization in the fluidisation section, and in bed, finish heat exchange, drying process with material, dry good material is discharged by fluid bed dryer (8), tail gas emptying after dust removal installation purifies of discharging from fluid bed dryer (8) top.
In the described one-level drying, wet stock is sent into pneumatic drier (14) through conveyer device﹠apos (15); The high temperature drying air be by dry air after 2# air filter (17) filters, and make after 5# vapor heat exchanger (16) heat exchange, wherein 5# vapor heat exchanger (16) is connected with flash tank (1); Described dust removal installation is to be composed in series by tornado dust collector I (13) and tornado dust collector II (14).
In the described secondary drying, the high temperature drying air by dry air after the 1# air filter filters (2), sucking the pressurization back by gas blower (5) divides four the tunnel to send into 1# vapor heat exchanger (3), 2# vapor heat exchanger (4), 3# vapor heat exchanger (6), 4# vapor heat exchanger (7) respectively, each interchanger also is connected with flash tank (1) respectively, gained high temperature drying air passes air distribution plate again and enters bed through fluid bed dryer (8) bottom air compartment; Described dust removal installation is for being arranged on the tornado dust collector III (9) and the tornado dust collector IV (10) at fluid bed dryer (8) top.
Described pneumatic drier (14) adopts gas-solid phase cocurrent cooling operation, and velocity of medium is greater than 15 meter per seconds in it, and time of drying is generally at 0.5~2 second; At surperficial gasifying stage, material is in 60~65 ℃ of the wet-bulb temperature of the gas that is in contact with it all the time.5, chlorinated polyethylene drying process according to claim 1 is characterized in that: described chlorinatedpolyethylene material carries out deep dehydration in fluid bed dryer (8), be no less than 120 minutes time of drying.
The present invention as drying medium, adds secondary fluidised bed drying by the one-level pulsed pneumatic drying with warm air, is moisture content that moisture content is less than 0.3% finished product greater than 30%~55% chlorinatedpolyethylene drying.Air stream drying uses high temperature air to carry out surface water rapid drying, and fluidized-bed adopts multistage differing temps air intake air to make goods fluid, and material is carried out depth drying.
The invention has the beneficial effects as follows:
1. the chlorinatedpolyethylene dehumidification system is realized carrying out continuously from being dosed to discharging, and the centre does not have personnel's intervention operation, has reduced labor strength, and fluidized-bed bed temperature-stable does not have heating and cooling process, reduces energy wastage, the thermo-efficiency height.After the normal operation of simultaneity factor, material is residence time basically identical in bed, and the product water content is low and stable.
2. according to the drying property of chlorinatedpolyethylene, one-level adopts the pulsed gas flow drying, use high temperature air in the extremely short time, to take off the surface water of chlorinatedpolyethylene, pneumatic drier adopts gas-solid phase cocurrent cooling operation, at surperficial gasifying stage, material is in the wet-bulb temperature of the gas that is in contact with it all the time, generally be no more than 60~65 ℃, in the dry stage that latter stage, temperature of charge rose, gas temperature reduces greatly, therefore, can use high-temperature gas, the gas-solid biphase is extremely short duration of contact in drying tube, and time of drying is generally at 0.5~2 second.The thermally denature of chlorinatedpolyethylene generally is the function of temperature and time, so material can not cause overheated or decompose and influence its quality.The pulsed gas flow drying machine can be given full play to high heat and mass effect simultaneously, with intensified drying process.
3. air stream drying is owing to the gas velocity height, and particle is good dispersion in gas phase, and the exsiccant useful area increases greatly.Simultaneously, because dispersion and agitaion when dry are brought in constant renewal in the gasification surface, therefore, exsiccant conducts heat, mass transfer process intensity is bigger.
4. secondary drying adopts fluidized-bed to carry out deep dehydration, chlorinatedpolyethylene in fluidized-bed under certain wind speed, blown afloat and be suspended in by fluid and do free movement in the fluid, collision mutually mixes between particle, and bed height rises, whole bed presents the form of similar liquids, the charge level of one basic horizontal is arranged at the bed top, and the severe smaller particles is floated on it, and this phenomenon is called the solid particulate fluidised formization.And the mean wind speed of this moment is called normal fluidizing velocity, can regulate the residence time of material in bed by regulating the material thickness of material in bed, and chlorinatedpolyethylene can reach the material requirement when the bed inner drying is more than 120 minutes.
5. rationally the selection of inlet temperature divides the multistage air intake according to the difference of material dewatering degree, has both improved thermo-efficiency, does not make material overtemperature in bed again.
6. each equipment is carried out electrostatic grounding, avoids chlorinatedpolyethylene dangerous because of static focus produces.
Description of drawings
Fig. 1 is a process flow sheet of the present invention;
Wherein, 1, flash tank, 2, the 1# air filter, 3,1# vapor heat exchanger, 4,2# vapor heat exchanger, 5, gas blower, 6, the 3# vapor heat exchanger, 7,4# vapor heat exchanger heating, 8, fluid bed dryer, 9, tornado dust collector III, 10, tornado dust collector IV, 11, induced draft fan, 12, tornado dust collector II, 13, tornado dust collector I, 14, pneumatic drier, 15, conveyer device﹠apos, 16,5# vapor heat exchanger, 17, the 2# air filter, 18, air sealer.
Embodiment
The invention will be further described below in conjunction with accompanying drawing and embodiment.
Among Fig. 1, this dehumidification system thermal source adopts warm air, the one-level drying: wet material adds pulsed gas flow drying machine 14 by conveyer device﹠apos 15, dry air filters by 2# air filter 17, fully contact with the high temperature air of 5# vapor heat exchanger 16 heat exchange, material is preliminarily dried in pulsed gas flow drying machine 14, enters fluid bed dryer 8 by the corresponding separately air sealer 18 in tornado dust collector II12 and tornado dust collector I13 bottom, tail gas after induced draft fan 11 pressurizations by the evacuated tube emptying.
Secondary drying: the material after the primary pre-drying is joined in the fluid bed dryer 8 through elephant trunk by air sealer 18.Air filters through 1# air filter 2, sucking the pressurization back by gas blower 5 divides four the tunnel to enter 1# vapor heat exchanger 3,2# vapor heat exchanger 4,3# vapor heat exchanger 6,7 heating of 4# vapor heat exchanger respectively, air admission fluid bed dryer 8 bottom air compartments after the heating pass air distribution plate again and enter bed.The air that enters bed in this process is effectively controlled, thereby makes an interior material keep stable fluidization, and with bed in finish heat exchange, drying process with material.The exsiccant material is discharged through the overflow port of fluidized-bed, enters air-transport system, and the tail gas of discharging from the fluidized-bed top purifies the back emptying through tornado dust collector III9 and tornado dust collector IV10.Flash tank 1 is connected with 1# vapor heat exchanger 3,2# vapor heat exchanger 4,3# vapor heat exchanger 6,4# vapor heat exchanger 7,5# vapor heat exchanger 16 respectively.
Velocity of medium is greater than 15 meter per seconds in the pneumatic drier 14, and the gas-solid biphase is extremely short duration of contact, and time of drying is generally at 0.5~2 second.The thermally denature of material generally is the function of temperature and time, and it is overheated therefore can not cause for the bonding material of this hot mastication of chlorinatedpolyethylene, causes danger.Pneumatic drier adopts gas-solid phase cocurrent cooling operation, and, at surperficial gasifying stage, material is in the wet-bulb temperature of the gas that is in contact with it all the time, generally is no more than 60~65 ℃, in the dry stage that latter stage, temperature of charge rose, gas temperature reduces greatly, therefore, can use high-temperature gas.
Secondary drying adopts fluidized-bed to carry out deep dehydration, chlorinatedpolyethylene in fluidized-bed under certain wind speed, blown afloat and be suspended in by fluid and do free movement in the fluid, collision mutually mixes between particle, and bed height rises, whole bed presents the form of similar liquids, the charge level of one basic horizontal is arranged at the bed top, and the severe smaller particles is floated on it, and this phenomenon is called the solid particulate fluidised formization.And the mean wind speed of this moment is called normal fluidizing velocity, can regulate the residence time of material in bed by regulating the material thickness of material in bed, and chlorinatedpolyethylene can reach the requirement of dry materials when the bed inner drying is more than 120 minutes.