.Air Engineering Fields

Paper Industry: Ventilation

Air systems

Blowing systems
Beside the steam & condensate system, without a well designed blowing air system the paper machine efficiency will be limited in quantity and in quality. With the AESA blowing boxes and ventilation systems, the optimisations are :

  • An even distribution of air in the hood to avoid humidity pockets ;
  • An adequate blowing of air to avoid the sheet fluttering and so :
    • Better energy transfer ;
    • Higher running speed

AESA design and manufacture hoods for the paper machine with insulation and easy access feature so to avoid condensation and have easy maintenance.

A proper hood design has five main purposes :

  • Collect the humidity of the evaporation process ;
  • Limit the leakage of hot and humid air in the working area ;
  • Allow an efficient ventilation of the drying sections with hot and dry air ;
  • Limit the heat losses by radiation ;
  • Optimize the machine efficiency and allow the recovery of the exhaust air heat.

Heat recovery systems
In the ventilation process, fresh air is taken from outside. This air needs to be heated to the right condition so to have an efficient drying of the paper sheet. Via Heat Plates Exchanger (HPE) and Steam Heat Exchanger on the incoming fresh air stream, we can minimize the heating requirement and reuse available heat of the blow through and flash steam as well as the heat of the exhaust air

The advantages are as follows :

  • Recovered heat :
    • Cost saving ;
    • Less water consumption
    as we condensate part of the exhaust air humidity and so part of the evaporated water goes back to the process
  • Exhaust air dehumidification :
    • Reduce the mist formation and droplet at the exhaust outlet

For the process where the exhaust air contains dust or fluff, the HPE is provided with a water spray cleaning system. This cleaning system maintain the efficiency of the heat exchanger and reduces the fire hazard. It can be used as a fire fighting device. Waste water is to be collected separately.

Illustration n°1

Illustration n°2

Illustration n°3

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