1、 Design Description of Vacuum Disc Drying Machine
1. Performance and Scope of Application
The vacuum disc continuous dryer designed and produced by our company is an efficient and energy-saving continuous drying equipment that has been improved and innovated based on the absorption of domestic and foreign technologies. Its unique structure and working principle determine that it has high thermal efficiency, low energy consumption, small footprint, simple configuration, and convenient operation and control. Good operating environment and other characteristics. Widely applicable to product drying operations in industries such as chemical, pharmaceutical, pesticide, feed, and new materials.
2、 Working principle and process of vacuum disc dryer
Wet materials are continuously added to the feeding hopper of the main machine. The upper electric vacuum ball valve is opened to distribute the materials alternately into the top two material tanks. The vacuum ball valves on the upper and lower parts of the material tanks are alternately opened and closed. The materials are continuously added to the first layer of the drying disc on the upper part of the dryer under the action of the mixing motor. The rake arm with rake blades rotates to make the rake blades continuously flip the materials, allowing the materials to fully absorb heat. The materials flow along the exponential spiral line on the surface of the drying disc. The materials on the small drying disc are transferred to the outer edge and fall to the outer edge of the large drying disc below. The materials on the large drying disc move inward and fall into the lower small drying disc from the middle discharge port. The large and small drying discs are alternately arranged up and down, and the materials can continuously flow through the entire dryer. Insert heating medium into the hollow drying tray. The heating medium enters the drying disc from one end and exits from the other end. The dried material falls from the last layer of the drying tray onto the cooled bottom layer of the shell, and is then transferred by the rake blade to the discharge port to be discharged from the bottom two material tanks, and discharged through the upper and lower electric vacuum ball valves with alternating switches. The moisture evaporates and evaporates from the material, and is forcibly extracted by a vacuum pump from the upper and lower material tanks. The solvent is condensed by a condenser and enters the buffer tank for recovery, and the moisture is discharged into the air.
The vacuum disc dryer process is suitable for drying thermosensitive materials with very low temperature requirements, such as pharmaceuticals, vitamins, biological products, enzymes, solvent containing materials, etc. Wet materials are added in batches to a quantitative feeder that can withstand negative pressure. After turning on the vacuum pump to put the disc dryer in a negative pressure state, the materials are evenly added to the dryer through a continuous lock for drying operations. The dried materials are discharged from the discharge port at the bottom of the dryer. The moisture escaping from the material is recovered through the condenser and solvent receiving tank, and the entire operation process is carried out under negative pressure.
3、 Vacuum disc dryer is suitable for materials:
The closed recovery solvent disc continuous dryer process is suitable for drying processes that require solvent recovery and drying processes where the moisture content is flammable, explosive, toxic substances that cannot be directly discharged into the atmosphere and must be recycled. If the moisture content is methanol, ethanol, gasoline, pyridine, petroleum ether, halogenated hydrocarbons, acetone, formaldehyde, etc. On the basis of the basic configuration, add continuous material entry and exit locks, condensers, solvent receiving tanks, and vacuum pumps. The moisture (solvent vapor) escaping from the dryer enters the solvent recovery condenser from the top of the dryer, condenses into solvent liquid under the cooling of the cooling medium, and enters the solvent receiving tank. Non condensable gases leave the solvent receiving tank and are evacuated by a vacuum pump. The cooling medium should be selected based on the characteristics of the solvent, either cooling water or cold salt water.
1 Wet material 2 Quantitative feeder 3 Continuous ball valve feeding 4 Vacuum disc dryer 5 Condenser 6 Heating medium in 7 Heating medium out 8 Solvent receiver 9 Vacuum pump 10 Dry product 11 Cooling medium in 12 Cooling medium in 13 Exhaust gas exhaust
4、 Principle of nitrogen replenishment for vacuum disc dryer:
The disc continuous dryer process with nitrogen circulation protection is suitable for drying substances that are particularly prone to oxidation, highly flammable, explosive, and toxic substances. On the basis of basic configuration, equipped with solvent condenser, solvent receiving tank, inert gas circulation machine, fin heater, inert gas replenishment tank and other equipment. Wet materials are added to the dryer by a quantitative feeder through a continuous lock, and the drying process is completed by moving from top to bottom. The dry material is discharged from the bottom of the dryer through a continuous lock, and the moisture escaping from the material enters the condenser from the top of the dryer and condenses into liquid, flowing into the solvent receiving tank. The cooled inert gas is transported to the dryer by a circulation machine, absorbs the moisture of the material, and enters the condenser for re cooling, forming a closed-loop circulation. Before entering the dryer, the inert gas must be preheated by a fin heater, and the inert gas storage tank can replenish the lost nitrogen gas in the system.
5、 Unique features of vacuum disc dryer
The material enters the feeding hopper 1, and the pneumatic ball valves a and d are opened simultaneously. The material in the feeding hopper 1 enters the feeding transition bin 1, while the material in the feeding transition bin 2 enters the dryer under the action of the mixing device. The pneumatic ball valves a and d are closed at the same time, and the pneumatic ball valves b and c are opened at the same time. The material in the feeding hopper 2 enters the feeding transition bin 2. At the same time, the material in the feeding transition bin 1 enters the dryer under the action of the mixing device. This process is repeated, and the wet material continuously enters the top drying disc of the dryer.
The dried material enters the inlet of the pneumatic ball valve e under the action of the rake blade, and the pneumatic ball valves e and h open simultaneously. The dry material enters the discharge transition bin 1, and the material in the discharge transition bin 2 is discharged outside the dryer through the pneumatic ball valve h. Similarly, the dried material enters the inlet of the pneumatic ball valve g under the action of the rake blade, and the pneumatic ball valves g and f open simultaneously. The dry material enters the discharge transition bin 2, and the material in the discharge transition bin 1 is discharged outside the dryer through the pneumatic ball valve h. This process is repeated, and the dry material is continuously discharged to the outer packaging of the dryer.