Skip to main content

Process Unit Operations

Drying Systems

Do you know what drying system is the most efficient for your process?  What equipment will dry your material the fastest, without impacting quality, at a cost you can afford? EPIC is experienced at integrating custom drying solutions that minimize cost and maximize efficiency.

Drying can be achieved in many different ways, but it is always used to produce a dry solid from a wet feed. The four major ways to complete drying include:

  • Direct drying (convection)
  • Indirect drying (conductive/contact)
  • Radiant heat drying
  • Dielectric heat drying

Direct and indirect drying are the most common drying systems that we work with. Both methods can be used in batch or continuoDryer Systemsus processes. The most common types of dryers that we integrate are listed below by application type. This is a sample of drying methods we’ve worked with. Please contact an engineer today to discuss your particular application.

Popular Drying Equipment

We select the correct drying process and drying equipment that fits both your processing requirements and your budget. We evaluate equipment based on relevance to your application and total lifetime return on investment. In order to ensure objectivity in equipment evaluation, we do not form formal relationships with suppliers.

Continuous DIRECT Drying

Content to be toggled.

  • Rotary Dryers – Material flows in a rotating cylinder through which hot gases flow. NOTE: certain rotary dryers are a combination of indirect and direct drying methods by utilizing inner and outer shells.
  • Spray DryersWet feed is transformed into small liquid droplets by an atomizer or spray nozzle. The water droplets are heated until transformed into powder.
  • Tray dryers, belts & turbo dryers – Wet product passes beneath or through turbo dryers that blast the material with hot air
  • Fluid BedsMaterial is fed into a shaking perforated steel bed through which hot gases flow. The hot air fluidizes the material by lifting the particles as they are transported from one end of the dryer to the other.
  • Tunnel Dryers – Material on trucks move through a tunnel that blasts wet feed stock with hot air
  • Sheeting Dryers – A continuous sheet of wet feed stock passes through the dryer as festoons or as a tout sheet stretched on a pin frame
  • Pneumatic Conveying Dryers – This method is usually used in conjunction with grinding. Material is conveyed in high temperature, high-velocity gases to a cyclone collector
  • Through-Circulation Dryers – Wet feed stock is held on a conveying screen through which hot air is blown.

Continuous INDIRECT Drying

Content to be toggled.

  • Drum Dryers – Material is spun through a drum that has heated walls
  • Steam-Tube Rotary DryersVery similar to a drum dryer, but the walls of the drum have many tubes running through them to allow steam or hot water to heat the walls of the drum. Sometimes operated under a slight vacuum, material moves through the rotating drum. Solvent recovery can be achieved if desired.
  • Screw-Conveyor Dryers – A screw conveyor carries wet product through a dryer
  • Vibrating-Tray Dryers – Vibrating trays heated with steam or hot water are filled with wet material to be dried via contact with the tray. Trays are vibrated to move material around and make drying more efficient.
  • Cylinder Dryers – Used for continuous sheets, such as paper or cellophane. Material passes over the surface of a rotating cylinder that is usually steam heated and rotating.
  • Belt Dryers – A continuously moving belt conveys wet product in close contact with a steam-heated platen.

Batch DIRECT Drying

Content to be toggled.

  • Fluid beds – Instead of a continuous feed stream being fed into a fluid steel bed, batches of solids are fluidized in a stationary cart with a dust collector mounted above.
  • Tray & compartment dryers – Material is laid out on trays which may be resting on removable trucks. Hot air is blown across the trays
  • Through-circulation dryers – Materials are held on screen-bottom trays through which hot air is blown 

Batch INDIRECT Drying

Content to be toggled.

  • Vacuum rotary dryersMaterial is tumbled through a stationary, heated shell under vacuum. Agitator moving material may also be heated via steam to assist in drying.
  • Vacuum tray dryersWet product is laid out on shelves that are steam or hot-water heated.
  • Freeze dryersFrozen material is dried under a high vacuum
  • Agitated pan dryers – Any form of wet solid in small amounts is dried under atmospheric or vacuum conditions. Material passes through a series of moving, heated trays.

EPIC will help you select the correct type and size of drying equipment for your application. We integrate drying equipment into virtually any manufacturing process. The most common types of systems that include a drying unit operation include:

Contact an EPIC engineer today to start designing your custom modular process system.

EPIC Modular Process Systems
4134 Meramec Bottom Rd
St. Louis, MO 63129, US