CN1071014C

CN1071014C - High-efficiency cyclonic-bed combined drying technology

Info

Publication number: CN1071014C
Application number: CN 96102212
Authority: CN
Inventors: 俞芷青; 金涌; 易江林; 蒋大洲
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-02-14
Filing date: 1996-02-14
Publication date: 2001-09-12
Anticipated expiration: 2016-02-14
Also published as: CN1147621A

Abstract

The present invention relates to a novel rotary bed combined type drying technology. In the technology, after wet materials are initially dried with hot air in an air flow pipe, the pre-dried materials are collected by a cyclone separator, and the collected pre-dried materials enter a cyclone bed with hot air for secondary drying. The technology has the distinctive characteristics of sufficient energy utilization of hot air, low power consumption, high drying intensity, small size of equipment, low mounting height and reasonable flow path, and the technology is an ideal drying technology.

Description

High-efficiency cyclonic-bed combined drying technology

The present invention relates to a kind of high-efficiency cyclonic-bed combined drying technology.

The drying that contains wet solid material extensively sees multiple industrial process, is used for the energy consumption of dry materials process according to statistics, account for that whole industrial process energy consumes about 1/4, therefore develop energy-efficient drying process and equipment has significant impact to national economy.To powdery and fine particulate dry materials, technology and equipment that domestic most producers adopt are flash method, fluidized bed process, flash distillation/fluidized bed process.Shortcomings such as these methods all have its limitation, and it is bad that the capacity usage ratio that often shows as gas is lower, energy consumption is big, the time of staying distributes.Still in constantly improving and developing, it has roughly represented present dry technology level to said method at present.In order further to improve drying efficiency, prolong the time of staying of material in riser, external a kind of cyclone bed 2 and the dry new technology of gas flow tube tandem compound released recently, its techniqueflow is seen figure one.Wet stock in seconds is about to surface moisture and removes in hot-air enters gas flow tube 1, and enter immediately rotary flow desiccator 2 continue dry, until reaching requirement, product captures through cyclone separator 3, weary gas emptying discharging.

The cyclone bed drier is the key equipment in the system, its structure and drying principles are seen Fig. 2, high speed thermal current I is being carried the wet stock III of giving after doing, enter the most next hothouse from the bottom inlet VI tangential direction of cyclone bed 2, air-flow and material rotate in dry indoor high-speed, centrifugal force gets rid of solid material to the limit of cyclone bed 2 wall, the angular momentum smaller particles of air-flow then carrying secretly rises and enters a hothouse, be thrown toward the solid material of limit wall, assembling constantly glide along the inclined-plane ascending air with the center of back converges and enters a last hothouse, repeat the flow behavior of previous hothouse, material and wind flow out from cyclone bed 2 tops outlet VII at last, because material constantly is rotated in cyclone bed 2, get rid of wall, gathering and downslide etc., prolonged the motion path of material in cyclone bed 2 greatly, this has equaled to prolong the drying time of material, simultaneously owing to air-flow in cyclone bed 2 is all strengthened with Flow of Goods and Materials speed and relative speed difference, then equal to have strengthened mass tranfer coefficient between gas-solid, cause cyclone bed 2 to be compared with fluid bed and have higher drying efficiency with corresponding pneumatic conveying drying bed.This kind drying process is to be proposed by the Hoechst of Germany (Hoechst) company at first, but the weak point of this technology is:

1, because material and air-flow directly enter cyclone bed 2 after going out gas flow tube 1, air-flow in gas flow tube by the wet stock humidification, temperature is lowered, when in cyclone bed 2, continuing to do the drying medium use, dry motive force can obviously weaken, material can obviously be prolonged the drying time in eddy flow, more outstanding for this shortcoming performance of material of ask for something depth drying.

2,, will inevitably make the equipment volume of cyclone bed 2 big, power consumption is higher because the air-flow that enters gas flow tube will all enter cyclone bed 2.

3, owing to directly advance cyclone bed 2 behind the gentle effluent stream pipe of material, the cyclone bed inevitable requirement is installed in the gas flow tube top, the integral device height is improved.

The objective of the invention is to overcome the deficiency of existing technology, a kind of cyclone bed novel combination type drying process is provided, it compared with prior art, flow process of the present invention is more reasonable, energy consumption is lower, the thermal efficiency is higher, it is little also to have equipment, arrange characteristics such as compactness, reduced investment, more can embody the development trend of contemporary dry technology.

Technical scheme of the present invention is:

A kind of high-efficiency cyclonic-bed combined drying technology, system is made up of dilute phase and stream pipe and cyclone bed, it is characterized in that containing wet stock through the hot blast I in gas flow tube behind the preliminarily dried, carry out gas solid separation by cyclone separator, give dry material and in cyclone bed, carry out the final drying of secondary and obtain final products through the hot blast II again;

Described drying process, to contain wet stock and hot blast and all send into from the bottom of gas flow tube, and carry out cocurrent cooling operation, material advances cyclone separator with wind and carries out gas solid separation, weary gas emptying discharging after the separation, the solid material after the separation enters cyclone bed 2 with the hot blast II;

Described drying process, the material of discharging from cyclone bed enters cyclone separator with hot blast and carries out gas solid separation, and isolated solid material is as the packing of product, and the gas after the separation is incorporated into the middle part of gas flow tube, carry out drying with the hot blast I to containing wet stock, then discharging;

Described drying process, the hot blast I of using use high temperature common wind, the hot blast II is used the inferior high temperature wind of handling through dehumidification, also can use high temperature wind common time.

Below in conjunction with drawings and Examples enforcement of the present utility model is elaborated.

Fig. 1 is existing techniqueflow chart;

Fig. 2 is a cyclone bed dryer configuration schematic diagram;

Fig. 3 is an artwork provided by the present invention.

Each label is represented respectively among the figure:

Gas flow tube 1, cyclone bed 2, cyclone separator 3, cyclone separator 4, hot blast I, hot blast II, wet stock III, product IV, emptying V, gas and wet stock inlet VI, gas and dried material outlet VII.

Two bursts of dryings of being come by blower fan are heated to uniform temperature respectively with gas, the hot blast I directly enters airflow drying tube 1 and contacts, carries out elementary drying (being generally constant rate of drying) with the wet stock III, material behind the preliminarily dried is sent into cyclone bed 2 after cyclone separator 3 is pounced on collection, the hot blast II is introduced into cyclone bed drier 2, after finishing final drying to material, enter the middle part of gas flow tube drier 1 and hot blast I more together as elementary drying wind after dividing solid separation, last and hot blast I is together as lacking gas emptying V.Generally speaking, the wet stock III is carried out in gas flow tube 1 is constant rate of drying, shorter for proceeded via surface diffusion, required drying time, is generally several seconds; Be falling-rate periods of drying in cyclone bed 2, for interior DIFFUSION CONTROLLED, required drying time are longer, for needs depth drying or heat-sensitive substance, in order to improve the dry motive force in cyclone bed 2, the hot blast II can be carried out dehumidification earlier and be handled.

The present invention compared with prior art has following features:

1, the Btu utilization of high temperature air steam consumption more abundant, dry run reduces.

Because existing Process gas flow tube and cyclone bed series connection, emptying weary gas is the end in flow process, requires weary gas pair Final dry products still has certain drying capacity, therefore will inevitably require weary gas to have lower relative humidity and higher Temperature, and the discharging of the last weary gas of the present invention is the end in gas flow tube, material only carries out preliminarily dried, it is right to require The preliminarily dried material has the weary gas of drying capacity, and its relative temperature can be higher than existing Process, and temperature can be low In existing Process, this shows that the present invention is more abundant to the energy utilization of high hot-air, and the hot-air consumption is reduced, Adding hot-air also reduces with steam consumption. Mainly due to this factor, make the actual consumption of existing technological process than theoretical Energy consumption is much higher.

2, has higher dry tenacity

Because prior art is tandem-type connection, the gas temperature that enters cyclone bed is low, temperature is big. Dry tenacity is low; And The hot blast II that the present invention enters cyclone bed be fresh High Temperature Gas (sometimes also carrying out dehumidification processes), temperature height, humidity little, Motive force is big, dry tenacity is high.

3, the process power consumption is low

Because the prior art all gas all will be by gas flow tube and cyclone bed, its power consumption value is:

Gas gross * (gas flow tube pressure drop+cyclone bed pressure drop)

The present invention only is about 25% of the interior total flow of gas flow tube by the gas flow of cyclone bed, and therefore power consumption value of the present invention is:

Gas gross * (gas flow tube pressure drop+25% cyclone bed pressure drop)

So power consumption of the present invention has been saved than existing series connection technology: 75% gas gross * cyclone bed pressure drop.

4, equipment investment is saved

Because the present invention enters the throughput of cyclone bed only for about 25% of tandem-type connection, and the equipment volume of cyclone bed is reduced significantly, adds that the equipment setting height(from bottom) reduces, the equipment gross investment of making is obviously saved.

5, therefore hot blast II temperature, air quantity, temperature can realize the optimized operation of dry run according to being adjusted and control by the performance of dry material because cyclone bed of the present invention enters the mouth.

Claims

1, a kind of high-efficiency cyclonic-bed combined drying technology, system is by also stream pipe (1) and cyclone bed (2) are formed, it is characterized in that containing wet stock (III) through hot blast (I) in gas flow tube (1) behind the preliminarily dried, carry out gas solid separation by cyclone separator (3), give dry material and in cyclone bed (2), carry out the final drying of secondary and obtain final products through hot blast (II) again.

2, drying process as claimed in claim 1 is characterized in that containing wet stock and hot blast is all sent into from the bottom of gas flow tube (1), carries out cocurrent cooling operation, and material advances cyclone separator (3) with wind and carries out gas solid separation, the weary gas emptying discharging (V) after the separation.

3, drying process as claimed in claim 1, it is characterized in that entering cyclone separator (4) from the material that cyclone bed (2) is discharged with hot blast (VI) carries out gas solid separation, isolated solid material is as the packing of product, gas after the separation is incorporated into the middle part of gas flow tube (1), carry out drying with hot blast (I) to containing wet stock (III), then discharging.

4, drying process as claimed in claim 1, it is characterized in that the hot blast that uses (I) use high temperature common wind, hot blast (II) uses the inferior high temperature wind of handling through dehumidification, also can use high temperature wind common time.