Technical advantages and specific applications of flash drying equipment

The flash drying equipment is an airflow drying equipment system with a rotary pulverizing device. It organically combines fluidization, swirling, spouting, pulverizing and grading techniques. It is a fluidization technology, a swirling technology, a spray technology and An optimized combination of convective heat transfer technology for drying free moisture in materials. The wet material is dispersed into the heated gas stream through a dry air duct of the flash drying apparatus, and drying occurs for a few seconds. Flash drying equipment has been used in many industrial applications, including food, chemicals, minerals and polymers. Materials are also used in a wide range of applications, including powders, lumps, granules, flakes, pastes, gels and Both slurries and the like (reverse mixing of dry and wet materials is necessary when handling slurries, pastes or viscous materials). Flash drying equipment is one of the most widely developed drying equipments. In domestic flash dryers, it is also called cyclone dryer and rotary quick dryer. As a typical example of fluidized drying, the flash drying equipment not only realizes the continuous operation of dynamic drying, but also overcomes the shortcomings of low static heat efficiency, high labor intensity, serious environmental pollution and waste, so that the chemical products can be effectively implemented on the drying unit. The perfect unity of efficiency, quality, efficiency and environment.

The main body of the flash drying device is a cylindrical drying chamber, which is composed of a pulverizing fluidized section at the bottom, a middle drying section and a top grading section, and can simultaneously perform operations such as pulverization, drying and grading of materials. In addition, there are heaters, feeders, mixing and crushing systems, classifiers, drying supervisors, cyclones, bag filters, fans and other components. After the natural air is heated by the heating device, the air inlet of the flash drying device enters the stirring and pulverizing drying chamber from the bottom of the dryer at a suitable blowing speed, and spirally rises. At the same time, the material is quantitatively added into the tower by the feeder, and is heated with the hot air. Full heat exchange is carried out to produce strong shearing, blowing and rotating effects on the material, so that the material is micronized by centrifugation, shearing, collision and friction, and the mass transfer heat transfer is enhanced. At the bottom of the flash drying equipment, the larger and drier pellets are mechanically broken by the agitator, the moisture content is lower, and the particles with smaller particle size are entrained by the airflow, and further dried and fined during the ascending process. The dried product is discharged through a cyclone, and the dust-containing exhaust gas is discharged into the atmosphere by a pulse bag filter. Because of these technical features, flash drying equipment has the following distinct advantages over other drying equipment:

1. The flash drying equipment selects a special feeder to keep the feeding continuous and stable, and does not cause bridging, arching and clumping, especially suitable for viscous materials.

2. Because the drying time is short, the relative speed of the material and hot air is large and the hottest air is not in direct contact with the dry material, so it is suitable for the treatment of heat sensitive materials.

3. The inner cone structure at the bottom of the drying chamber, the scouring of the airflow to the wall and the unique structure of the agitator determine the material that the flash drying equipment can handle with certain viscosity.

4. Due to the crushing, scouring and collision of materials during the drying process, the surface area is increased and the drying is strengthened, so the drying strength of the flash drying equipment is relatively high.

5. Set the built-in material (swirl piece, ceramic ring or classifier) ​​in the drying tower and coordinate with the temperature of the inlet and outlet air. The flash drying equipment can effectively control the final moisture and fineness of the material.

6. A water compartment cooling device is arranged at the bottom of the drying chamber to prevent the material from being deteriorated in the high temperature region at the bottom.

7. The circumferential air velocity in the drying chamber is high, and the material residence time is short, which effectively prevents the material from sticking to the wall and the heat sensitive material from deteriorating.

8. The flash drying equipment operates under the condition of micro-negative pressure, eliminating the pollution of the operating environment, and adopting different dust-removing methods and dust-removing materials according to different materials (pulse bag type dust collector, water bath dust collector, venturi wet dust collector, etc.) . Therefore, the working environment is clean and environmentally friendly.

The large drying equipment available in the world is the application of flash drying equipment - some of the water evaporation in a single system equipment exceeds 20 tons per hour. The inlet gas temperature ranges from 200-1400 degrees Fahrenheit (100-650 degrees Celsius) while the gas flow rate reaches 120,000 cubic feet per minute (200,000 cubic meters per hour). The flash dryer has the advantages of high thermal efficiency, short drying time and good energy saving effect. The paste-like material can be directly dried to form a powdery dry product, which saves the steps of pre-drying pretreatment, pulverization after drying, sieving, etc.; due to the fast drying speed, the material is heated for a short time, and it is not easy to destroy the components of the dry material, especially It is beneficial to the drying of heat sensitive materials; the drying process is completely closed, no impurities are mixed in, the finished product is of high quality and the operating environment is good. At present, the flash dryer has designed a variety of models according to different materials, and has formed a series of products, which are more and more widely used in the chemical, pharmaceutical, light industry, food, mineral and other industries.

The more typical materials suitable for flash drying equipment are:

Inorganic materials: borax, calcium carbonate, hydroxide, copper sulfate, iron oxide, barium carbonate, antimony trioxide, various heavy metal salts, synthetic cryolite, manganese carbonate, magnesium carbonate, sodium sulfite, calcium hydrogen phosphate, aluminum oxide, oxidation Iron red, aluminum hydroxide, sodium acetate, white carbon black, bentonite, and the like.

Organics: lauric acid, benzoic acid, benzoic acid, sodium oxalate, cellulose acetate, melamine, triphenylacetate, methyl cellulose, bromine, DSD acid, 2,4-D acid, H acid, J Acid and so on.

Pesticides: Atrazine (pesticide insecticide), Bataan, insecticide, mancozeb, broom, methomyl, quizalofop, tricyclazole, mefenacet, paclobutrazol, alfalfa Go to Tianjin, annihilation, imidacloprid, etc.

Pigment dyes: phthalocyanine dye, indigo dye, chrome orange, iron yellow, tartrazine, light fast black G, titanium ***, lithopone, Zhongluo yellow, etc.

Hard salt series: calcium hard acid (magnesium, aluminum, zinc, antimony, chromium), dibasic aluminum phosphite, tribasic aluminum sulfate, and the like.

Building materials mining: calcium carbonate series, kaolin, bentonite, aluminum bauxite, magnesium hydroxide, ultra-fine quartz.

Food: soy protein, gelatinized starch, distiller's grains, wheat sugar, starch, bean paste, special flour, etc.

Medicine: pharmaceutical intermediates, riboflavin, egg ***, huangliansu, VB, sulfadiazine.

Ceramic: kaolin, silica, clay, etc.

Industrial waste: biological mud, iron manganese slag, sugar aldehyde residue, etc.