The medium-sized spray dryer (usually with a processing capacity of 5-25kg/h) is the key equipment for the transition from laboratory to industrialization. It is widely used in the fields of food, medicine, chemical industry and nano materials, and is used to convert liquid materials (such as extract, lotion, suspension) into micron grade dry powder with good fluidity in one step. The advantages of medium-sized spray dryer, such as high efficiency, continuity and heat sensitivity protection, are derived from the precise cooperation of multiple functional modules.

1. Feeding system

Composed of peristaltic pumps or diaphragm pumps, it has the characteristics of no pulsation, corrosion resistance, and adjustable flow rate (0.5-30L/h). Some models are equipped with liquid level sensors and automatic start stop functions to ensure continuous and uniform feeding, avoiding nozzle dry burning or blockage.

2. Atomization device

The mainstream uses centrifugal atomization discs or two fluid nozzles:

Centrifugal disk (speed 8000-25000 rpm): suitable for high solid content, high viscosity materials, wide particle size distribution (10-100 μ m), and high yield;

Two fluid nozzle: uses compressed air to shear liquid, resulting in finer droplets (5-30 μ m), suitable for thermosensitive substances (such as proteins and probiotics), but requires a clean air source (≥ 0.6MPa).

The atomization effect directly determines the particle size, solubility, and yield of the product.

3. Drying tower body

Made of 304/316L stainless steel, with mirror polished inner walls (Ra ≤ 0.4 μ m) to reduce powder adhesion. The hot air inside the tower comes into contact with the mist droplets, with an inlet temperature of 150-250 ℃ and an outlet temperature of 80-100 ℃. The drying time is only 3-10 seconds, effectively protecting the active ingredients. The conical bottom is equipped with a gas scanning device to prevent powder accumulation and agglomeration.

4. Hot air system

Electric heating or gas hot air stoves provide clean hot air, which is filtered by high-efficiency filters (H13 level) to remove particulate matter and avoid product contamination. The PID temperature control accuracy reaches ± 1 ℃, ensuring process repeatability. Some models integrate waste heat recovery devices, saving over 15% energy.

5. Powder collection system

Main cyclone separator: recovers 85% -95% dry powder, compact structure, and low pressure loss;

Bag filter or secondary cyclone: captures fine powder with a total yield of over 98%;

The discharge port is equipped with a quick opening valve and inert gas protection (optional) to prevent oxidation or moisture absorption.

6. Control system

PLC+touch screen realizes fully automatic control, which can set and record parameters such as feed speed, inlet and outlet temperature, fan frequency, etc. Support data export and remote monitoring, comply with GMP/GLP standards, and meet the needs of scientific research and pilot testing.