LPZ Co-current Pressure Spray Granulating Dryer

Overview

  LPZ Co-current Pressure Spray Granulating Dryer is mainly suitable for spray drying heat-sensitive, instant-soluble materials, or materials with specific requirements for product particle size. It features a short contact time between the product and high temperature, and does not stick to the tower in the high-temperature zone. The dried product suffers minimal loss of components and is not prone to discoloration or coking. An ideal particle size range can be obtained by adjusting the spray pressure. The dried product has good flowability and solubility, and can be combined with other drying equipment such as a vibrating fluidized bed for secondary drying or cooling. The equipment is widely used in food, feed additives, and fine chemical industries, including powdered oils and fats, flavors and fragrances, natural pigments, biological proteins, vitamins, instant tea, etc.

Working Principle

  The feed liquid is delivered by a high-pressure pump (usually at 10–20 MPa) to a pressure nozzle installed at the top of the drying tower. Under high pressure, it is atomized into micron-sized fine droplets. Meanwhile, clean air, after being heated, also enters through the hot air distributor at the top of the tower and flows in the same direction (from top to bottom) as the sprayed droplets, forming co-current contact. During the co-current process, the droplets fully exchange heat and mass with the hot air, and the moisture evaporates rapidly within seconds. The dried particles then descend with the airflow to the bottom of the tower and are discharged.

Features

  Key product features include: In co-current drying, the droplets and high-temperature hot air move in the same direction. When the material first contacts the high temperature, moisture evaporates extremely quickly, while the material itself remains at a relatively low wet-bulb temperature (about 50–70°C). Therefore, it is highly suitable for drying heat-sensitive materials. By adjusting parameters such as spray pressure, granular products with good sphericity, uniform particle size, good flowability, and excellent instant solubility can be obtained. In addition, the co-current process is simple, not prone to tower sticking, stable in operation, and suitable for continuous production.

Applications

  The equipment is widely used in food, feed additives, fine chemicals, and other industries, including powdered oils and fats, flavors and fragrances, natural pigments, biological proteins, vitamins, instant tea, etc.

Flow Diagram