In most spray drying chambers, drying products enter the bottom of the drying chamber, and then discharged through the draining device (main discharge or full discharge). The main discharge is to discharge most of the dry products directly from the bottom of the drying chamber. Only a small amount of fine products are discharged from the main powder of the spray drying chamber to the powder cyclone separation system for recycling.

The main discharge from the bottom of the cone. Exhaust gas is discharged from the side of the cone bottom. The product collection at the conical bottom is caused by the airflow in the cone. The product collected on the flat bottom of the drying chamber is separated from the gas and falls to the floor at a certain speed. These two structures can handle lump shaped products. Thermoplastic powder and high fat powder are best treated in a conical bottom dryer. The screw propeller used in flat bottom structure may cause blockage. The main characteristic of the two kinds of powder discharge structure is to reduce the height of the drying chamber. The further improvement of the conical bottom structure will turn the lower part of the cone into two cones.WShape drying room. The exhaust pipe of this structure is located in the center of the drying chamber. This structure still keeps some products from being separated. Because scrapers are used, materials are subject to mechanical force. In a fully discharged structure, the air velocity in the discharge pipe must be large enough to carry the product to the separation equipment. Because of the requirement of air powder feeding, this discharging method can not be used to deal with the agglomerated materials with viscosity when they leave the drying chamber after drying. However, sometimes cold air can be introduced into the discharge pipe to help convey the material.

For special products, we need toSmall spray dryerThe drying chamber is designed more finely. For viscous (thermoplastic) products, the wall of the drying chamber must be kept at low temperature. Therefore, cold air can be used to cool the drying chamber wall or to introduce another cold air or secondary cold air to clean the drying chamber wall. For easily adhered products, electric hammers, air hammers or other vibration devices can be installed, often acting on the drying chamber wall to vibrate adherent materials.