The drying equipment effectively prevents material from sticking to the walls and prevents heat-sensitive materials from deteriorating.

Different drying equipment has specific technical solutions that can simultaneously address the issues of material sticking to the walls and the degradation of heat-sensitive materials. The specific methods are as follows:‌

I. Spray Dryer (Most commonly used for processing heat-sensitive waste liquids/materials)

Anti-adhesion Solution

Structural Temperature Control: Use a double-walled drying tower and cool the walls with air to maintain a wall temperature below 50°C, preventing low-melting-point materials from melting and adhering to the walls. Alternatively, introduce secondary air tangentially via rotating air vanes to cool the tower walls, or install rotating air brooms to continuously sweep the tower walls.

Process Optimization: Adjust atomization parameters to ensure droplets are fully dried before contacting the tower wall, preventing semi-wet material from adhering; polish the inner walls to reduce dry powder adhesion; in severe cases, install air hammers to dislodge material.

Solution for Preventing Heat-Sensitive Degradation

Leverage the natural advantage of short drying times (only a few seconds) combined with precise temperature control: the inlet air temperature can be flexibly set, and the exhaust temperature is always kept below the material’s decomposition temperature to prevent prolonged exposure to heat; simultaneously, a fully enclosed drying environment reduces oxidation, effectively preserving the activity of heat-sensitive materials.

II. Flash Dryer (Suitable for High-Moisture Paste-Like Waste Liquids/Materials)

Anti-Adhesion Solution

A special cooling device is installed at the bottom of the drying chamber to prevent material degradation and wall adhesion in the high-temperature zone at the bottom; a classification ring combined with swirl vanes controls material fineness and final moisture content, reducing agglomeration and adhesion of wet particles.

Air intake at the bottom generates strong shear, lift, and rotational forces, creating a natural mechanical micronization effect; large wet particles are directly broken down by agitation, reducing wall adhesion and accumulation.

Solution for Preventing Heat-Sensitive Degradation

High circumferential air velocity and short residence time within the drying chamber prevent heat-sensitive materials from degrading due to prolonged exposure to heat. This enables the production of uniform powdered products in a single drying cycle, eliminating the need for additional grinding processes.

III. Paddle Dryer (Suitable for High-Viscosity Sludge/Extract Materials)

Anti-Adhesion Solution

Mechanical Self-Cleaning: The serrated edges of the paddles generate shear forces, which, combined with a wall-scraping structure featuring 0.2–0.3 mm gaps, automatically peel off material adhering to the drum walls, achieving a cleaning efficiency of over 99.5%.

Surface Modification: The inner wall is mirror-polished (Ra ≤ 0.2 μm) to reduce adhesion. For highly corrosive materials, a non-stick, wear-resistant tungsten carbide coating can be applied, reducing cleaning frequency by over 50%.

Solution for Preventing Heat-Sensitive Degradation

Hollow paddle blades are used for conductive heating, ensuring uniform and controllable material heating. Combined with a process gradient that starts at low temperatures and gradually increases, this prevents instantaneous dehydration, softening, and sticking to the walls, as well as thermal degradation of the material.

IV. Square Vacuum Dryer

By utilizing a low-pressure vacuum environment to lower the boiling point of water, drying can be completed at low temperatures between 30–80°C, completely avoiding the destruction of heat-sensitive components caused by high temperatures. At the same time, static drying without mechanical agitation eliminates heat generated by shear friction, thereby maximizing material stability.