Industrial Dryers

Spray Dryer

Most Popular Drying Technology:

A method of producing dry powder from liquid or slurry by rapidly drying with hot air. The spray dryer transforms liquid products into dried powders by spraying them into a controlled flow of hot air within a drying chamber.

Product Characteristics: Spray-dried powders consist of single particles or agglomerates. Final powder properties depend on the physical and chemical properties of the liquid feed and the dryer design and operation.

Types of Spray Dryers:

• Tower Dryer/Tall Form Dryer: Vertical design for high throughput
• Ceiling Exhaust Dryer (MSD): Medium capacity applications
• Bottom Exhaust Dryer (CMD): Compact design for space-constrained installations

Salient Features:

• High Production Rate - continuous operation capability
• Gentle drying - preserves heat-sensitive materials
• Short drying period - seconds to minutes
• Continuous operation - no batch changeover downtime
• Uniform product production - consistent quality
• Fully automatic plant - minimal operator intervention
• High thermal efficiency - optimized energy usage

Applications: Milk powder, coffee powder, detergent, pharmaceutical products, food ingredients, dairy whitener, SMP/WMP

Fluid Bed Dryer (FBD)

Technology: Moist product is put into turbulent motion using hot air. Simple fluidized bed with air can be used for drying. Mechanical stirrers can be incorporated to break up agglomerates if particles tend to stick together.

Configuration: Manufactured in various sections (2, 3 & 4 sections) for different capacity requirements.

Features:

• Uniform drying through fluidization
• Excellent heat and mass transfer
• Suitable for granular materials
• Can incorporate cooling and coating sections
• Easy to clean and maintain

Applications: Pharmaceutical granules, food ingredients, instant mixes, chemical powders

Vacuum Band Dryer

Specialty Dryer: Specially designed to provide products with gentle thermal treatment, making it suitable for viscous liquids or pastes.

Design: Comprises a vacuum chamber housing conveyor bands that pass over platens heated by steam or hot water.

Capacity Options: Supplied with a range of capacities using single to ten band configurations.

Features:

• Low temperature drying under vacuum
• Preserves heat-sensitive compounds
• Continuous operation capability
• Uniform thickness control
• Gentle handling of viscous materials

Applications: Fruit purees, vegetable pastes, herbal extracts, specialty chemicals

Vacuum Shelf Tray Dryer

Batch Dryer Technology: Indirect heated batch dryers consisting of a vacuum-tight chamber, a vacuum source, and a condenser.

Size Range: Available in sizes from 1 to 24 shelves. Largest chambers have dimensions of 9 feet wide, 18 feet long & 8 feet height.

Ideal Applications:

• Drying pharmaceuticals and food products
• Temperature-sensitive or easily oxidizable materials
• Valuable materials where labor cost is insignificant
• Small batches of materials wet with toxic or valuable solvents

Features:

• Low temperature operation under vacuum
• Oxygen-free environment prevents oxidation
• Solvent recovery capability
• Precise temperature control

Ring Dryer

Modified Flash Dryer: A modified version of flash dryer designed to improve efficiency of pneumatic dryer with an internal classifier (manifold).

Working Principle: Heavier material is held in airborne recycle for further drying. Incorporates a disintegrator - a fixed beater hammer mill to break up wet material for uniform fine powder.

Benefits:

• Reduces natural stickiness of the product
• Prevents material build-up in system
• Improves drying efficiency through classification
• Produces uniform particle size

Roller Dryer (Drum Dryer)

For Liquid Products: Used for liquid products of either low or high viscosity.

Application: Manufacturing of skim milk powder for chocolate, ice cream, confectionary and baby food.

Configuration: Consists of single or double rollers with or without applicator rollers. Metal rollers are heated from inside through condensing steam.

Process: Product dries as a thin film on the cylindrical surface. The thin film of product on the hot drum is scrapped off by a knife in flakes or scales. The scrapper knife is made of spring steel and is exchangeable.

Features:

• Continuous operation
• High heat transfer efficiency
• Suitable for heat-stable products
• Simple and robust design

Rotary Dryer

Industrial Workhorse: Industrial dryer employed to reduce or minimize liquid moisture content by direct contact with heated gas.

Application: Widely used in herbal extract drying and similar applications.

Features:

• Large capacity handling
• Continuous operation
• Robust construction
• Suitable for free-flowing materials

Rotary Vacuum Dryer

Advanced Drying Technology:

• Uniform drying avoids overheating of product
• High Drying Rate under vacuum conditions
• Gentle tumbling action prevents degradation
• Suitable for heat-sensitive materials
• Excellent for pharmaceutical applications

Closed Loop Dryer

For Solvent-Based Systems: Used for non-aqueous solutions (feed containing solvent).

Application: Required for herbal/pharmaceutical products that need solvent-based extraction.

Safety Feature: Drying operations are done in an inert gas atmosphere under a closed cycle due to explosive nature of solvents.

Inert Gases Used:

• Nitrogen (most common)
• Superheated steam
• Carbon dioxide (CO₂)

Benefits:

• Solvent recovery and reuse
• Explosion-proof operation
• Environmental compliance
• Cost savings through solvent recycling

Spin Flash Dryer

Pneumatic Drying Technology: Falls into the category of pneumatic conveying cum drying.

Working Principle: Feed is injected just above a rotating disintegrator, with hot air ejection from the bottom. Disintegrated material is brought into contact with hot drying media, drying the particle and conveying it pneumatically for separation.

Features:

• Rapid drying in seconds
• Mechanical disintegration for uniform particle size
• Compact footprint
• Continuous operation
• Energy efficient