The hollow shaft of the paddle dryer is densely arranged with wedge-shaped hollow paddles, and the heat medium flows through the paddles through the hollow shaft. The heat transfer area per unit of effective volume is large, and the temperature range of the heat medium is -40℃～320℃. It can be steam or liquid: such as hot water, heat transfer oil, etc. Indirect conduction heating does not carry air to carry heat away. Heat is used to heat materials. Heat loss simply dissipates heat to the environment through the body's thermal insulation.
The heat transfer surfaces of the wedge-shaped blades are self-cleaning. The relative motion between the material particles and the wedge surface creates a scrubbing effect that washes away adhering material from the wedge surface and maintains a clean heat transfer surface during operation. The shell of the paddle dryer is W-shaped, and there are generally two to four hollow stirring shafts in the shell. The shell is provided with a sealing end cover and an upper cover to prevent the leakage of material dust and collect material solvent vapor. A baffle is set at the discharge port to ensure the height of the material level, so that the heat transfer surface is covered by the material, and its function is fully exerted. The heat transfer medium flows through the casing and the hollow mixing shaft through the rotary joint. Depending on the type of heat medium, the hollow mixing shaft has different internal structures to achieve heat transfer effects.
There are some basic steps the machine operator should follow in order to keep the drying cylinder running well. It is worth noting that:
Uneven water distribution can lead to undercoating. The milling cutter should check that the scraper is properly adjusted or worn. Periodic inspections are required to determine if the entire surface is coated, otherwise the scraper will wear off the uncoated surface.
Uneven wear on the blade indicates possible problem or unnecessary wear on the coating. The profile of the scraper should be aligned behind the dryer surface for even wear.
Surface edge wear does not directly affect production, but can result in unnecessary material volumes. The next grinding must be done from the inside of the dryer to get the correct crown profile.
