Introduce

Hollow Blade Dryer is a kind of horizontal stirring continuous drying equipment based on heat conduction. Because the heat required to dry the device relies on heat conduction to indirectly heat, the drying process does not need or require a small amount of gas to take the wet part. It greatly reduces the heat loss caused by air flow, improves the heat utilization and is a kind of energy-saving drying equipment. Paddle dryer is widely used in petrochemical, chemical, metallurgy, food, medicine, pesticides and other industries in the powder, granular, cake-like, serous material drying.

Working principle

Hollow blade dryer Heat transfer surface has blades, stirring shaft, wall surface and other parts, and the heat transfer area of the blade accounted for a large part, so the equipment structure is compact, the unit volume Heat transfer area is large. In addition, mixing and mixing make the material turn violently, so as to obtain high heat transfer coefficient, so the space is small, saving the construction cost of the plant. The drying process is less gas, low flow rate, the amount of dust taken away by the gas is less, so the gas dust recovery is convenient after drying, the recovery equipment volume is small, can save equipment investment. For drying processes that require recovery of solvents, solvent concentrations can be greatly improved. Due to the special structure of the paddle blades, the materials are alternately squeezed and loosened during the drying process, reinforcing the drying. Dry indoor material filling rate is very high, can reach 80%-90%, the material dwell time by adjusting the feeding speed, stirring shaft speed, material full degree parameters can be adjusted from a few minutes to a few hours of arbitrary adjustment. In addition, the material in the dryer from the feeding mouth to the discharge mouth movement is basically piston movement, the residence time distribution is narrow, thus the product moisture content uniformity. The blades have a certain axial angle on the stirring shaft, so the material can be dried continuously.

Equipment structure

The structure (hollow blade dryer can be divided into single, double and four roots) is described as an example of biaxial type. It is composed of a W-type shell, a top cover, two hollow shafts with blades, a end cover at both ends, a rotary joint with a medium, a metal hose and a transmission mechanism including gears and sprockets.

The core of the device is two hollow shafts and hollow agitator blades welded to the shaft. The blade shape is a wedge-shaped hollow semicircle that can be used to heat the medium. In addition to stirring, it is also the heat transfer body of the equipment. The two main heat transfer side of the blade is inclined, so when the material is in contact with the slope, as the blade rotates, the particles quickly slide away from the inclined plane, so that the heat transfer surface is continuously updated and the heat transfer is intensified. A scraper is arranged at the bottom of the triangle of the blade to scrape the material deposited on the shell to prevent a dead end.

Blade arrangement and the size of the various parts have a certain requirements, but also in the feeding area, drying area, the discharge area in addition to the blade, the other with auxiliary mechanisms to ensure stable operation of the machine, dry evenly. In addition, the residence time can be adjusted.

Equipment features

The main features of the paddle dryer are:

1, the equipment structure is compact, the effective heat transfer area is large, covers the area small

2, mixing evenly, high thermal efficiency, good drying effect

3, the blade shaft can engage with each other, with self-cleaning action, to prevent material adhesion wall

4, low energy consumption, small operating costs

5, small dust entrainment, less material loss

6, indirect heating, non-polluting materials

7, the blade shaft speed is low, does not destroy the product shape and the nature

10, the equipment operation elasticity is big, the operation is stable and reliable

Application

Paddle dryer has been successfully used in food, chemical, petrochemical, dyes, industrial sludge and other fields. The heat transfer, cooling and stirring properties of the equipment enable the following unit operations: calcination (low temperature), cooling, drying (solvent recovery), heating (melting), reaction and sterilization. The stirring blade is also the heat transfer surface, which increases the heat transfer area in the unit effective volume and shortens the processing time. The heat transfer surface of wedge blade has self-cleaning function. Compression-expansion stirring function makes the material mix and even. The material is in the axial direction of the "piston flow" movement, in the axial interval, the material temperature, humidity, mixing degree gradient is very small.

Using heat conduction oil as thermal medium, the impeller dryer can finish the work of low temperature calcination. such as: Calcium sulfate dihydrate (CaSO4 2H2O) calcined into a semi-aqueous calcium sulfate (CaSO4 1/2H2O). Sodium bicarbonate (NaHCO3) is calcined into soda ash (NA2CO3) and so on.

Cooling medium, such as water, cooling brine, etc. can be used to cool. Such as: used in the soda industry of the paddle-type soda machine, replacing the old-fashioned air cooling soda machine, saving energy and tail gas treatment equipment, reduce the operating costs, but also for titanium dioxide, nickel alloy powder and a variety of powder granular materials cooling. In a single machine, the material can be cooled from 1000 ℃ to less than 40 ℃.

Drying, the most important function of equipment, do not use hot air, so that solvent recovery, energy consumption, environmental control in the ideal state of easy to handle. The need to recover solvents, flammable and easy oxidation of heat-sensitive materials particularly suitable. has been widely used in fine chemical, petrochemical, dye industry.

The uniformity of temperature, humidity and mixing in the axial range allows the equipment to be used to heat or melt, or to react to some solid materials. In the fertilizer and modified starch industry has been successfully used. The paddle dryer can be used to sterilize food and flour. The large heating area within the unit's effective volume quickly heats the material to the sterilization temperature, avoiding long-time heating and changing the quality of the material.

Adaptation materials

1. Petrochemical industry: Polyolefin Powder, polycarbonate resin, high, low density polyethylene, linear low density polyethylene, acetal granules, nylon 6, nylon 66, nylon 12, acetate fiber, polyphenylene sulfide, propylene-based resin, engineering plastics, polyvinyl chloride, polyvinyl alcohol, polystyrene, polypropylene, polyester, pom, styrene ~ Acrylonitrile copolymerization, Ethylene ~ Propylene copolymerization.

2, Environmental protection industry: PTA Sludge, electroplating sewage sludge, boiler soot, pharmaceutical plant waste residue, sugar plant waste residue, monosodium glutamate plant waste residue, coal ash.

3, Feed industry: soy sauce slag, bone-based feed, lees, food under the corner material, Apple pomace, orange peel, soybean meal, chicken bone feed, fishmeal, feed additives, bio-slag mud.

4, food industry: starch, cocoa beans, corn, salt, modified starch, medicine.

5, Chemical Industry: soda ash, nitrogen and phosphorus potassium fertilizer, kaolin, bentonite, white carbon black, carbon black, phosphogypsum, sodium fluoride, nitric acid, calcium, magnesium carbonate, sodium cyanide, aluminum hydroxide, barium sulfate, calcium sulfate, calcium carbonate, dyes, molecular sieve, saponin.