Description

DESSICA DS systems are modular dehumidification and air treatment units (hygrometry, temperature and dust) specially designed to meet the requirements of users for building or industries.
These systems include the latest innovations for adsorption desiccant rotors and use the new energy saving system (Dessica’s patent).
DESSICA DS systems offers a complete solution including filtration, heat exchangers and adapted regulation system.
The third generation PPS and PPX silica gel desiccant rotors mounted on our air dryers contains a high active silica gel component.

It provides a high dehumidification performance and reduce energy consumption compared to other silica gel desiccant rotors of the same dimensions.
They are made of self-supporting panels (pre-lacquered sheet, galvanized steel or stainless steel 304L or 316L) double skinned (without aluminum sides) insulated by 2-inches high-density mineral wool.
Two models are available: outdoor or indoor installation.
Envelope (Classified according to EN1886)

Mechanical resistance: class 2A
Thermal performance :
• Thermal transmission : class T2
• Thermal bridging : class TB2
· Filter drift leak : class F9
· Airtightness casing : class B

Benefits

  • Modular and adaptable
  • Double skin insulation 2 inches
  • PLC automated control
  • Indoor & outdoor versions
  • Integrated Heat Recovery

Applications

DESSICA DS systems supplies dry air to drying processes, production processes or again packaging and storage environments. They are designed to treat air or be installed in air conditions between 5 F and 105 F (-15 °C and 40 °C). Mastering hygrometry makes it possible to control specifics products or systems :

  • the production capacity of drying systems (ovens, towers, fluidized beds, etc.…)
  • clogging and bulking of pulverized products
  • corrosion
  • condensation
  • the quality of hygroscopic materials
  • the development of bacteria and the spread of micro-organisms
  • icing
  • the humidity level of buildings
  • mold

Some industries such as pharmaceutical, food processing, energy, metallurgy and electronics requires a precise and high dry air quality, this is what DESSICA DS systems provide.

Operating principle of the desiccant rotor with an integrated heat recovery

Schema_ANG_redimensionnement_AurélieThe DS system uses two independent air flows. The main air flow will be dried, the secondary air flow of lesser volume will be used to evacuate the moisture retained by the desiccant rotor.

Two fans move two distinct air streams through the desiccant rotor. The main air stream or air to be treated passes through the slowly rotating silica gel rotor.
Silica gel is a high- performance hygroscopic material able to retain the moisture content from ambient air. By floating through the rotor, the humid air loses its moisture captured by the silica gel material.
The dry air is then totally usable. The secondary air flow, called reactivation air, serves to evacuate the moisture retained by the rotor silica gel component.
A part of the air volume passes through the rotor by the heat recovery sector, cooling down the dehydrating material by simultaneously raising the air temperature.
The remaining flow by-passing the rotor is mixed with the purge flow. The preheated air is then brought to a final temperature of approximately 210 F to 270 F (100 °C to 130°C) by additional heating provided by electric, steam or direct gas coil. It will then pass through the rotor by counter current from process air flow to dry off the silica gel from its moisture.
The moisten air (wet air) leaves the dryer to be evacuated outside thepremises or building.

DESSICA DS system selection

DS system size depends mainly of the front air velocity towards the various internal components, therefore the process air flow.
Each component must be selected according to its own selection criteria. Usually, the desiccant rotor, the filtration systems, the chilled and hot water heat exchangers selection is crucial to define the casing sections from a DS unit. Other parameters may limit the airflow, such as the level of humidity or filtration to be achieved on outlet air or as well the fan’s dimensions.
The quick selection tables below are based on the sole criteria from desiccant rotor

Documentation