Vacuum Cooling System

vacuum coolingThe application  of vacuum cooling  technology  has caused  a revolution in the green vegetables cold  chain  distribution system. In summer time, vegetables tend to deteriorate very fast after  harvest from  the field  under  high  temperature.

 

 

Principle of vacuum cooling

It is therefore, necessary to cool the vegetables down  to about 0°C within a short time to preserve its freshness.The most effective method to cool down vegetables is under  vacuum through self-evaporation of water.The "main principle is when a vacuum chamber  is filled with green vegetables and evacuated, the free water in the cell tissues of the vegetables   begins to evaporate at a pressure  and the vegetables cool themselves due to the latent heat of the  evaporating water.Since  597 Cal  is required  to vaporize 1 gram  of water at 0°C, the vegetables are  cooled to  0°C in about  20-30  minutes when the chamber is maintained ~t a pressure of about  4.6 Torr. The large  amount of water  vapor  generated inside  the chamber is condensed  on the surface  of the cold  trap  and removed  from the chamber. The system uses a refrigerator  to keep the cold trap at a low temperature.

vacuum cooling

Advantage of Vacuum Cooling

  • Cooling  time is very  short, usually only 20-30 minutes.Therefore, it can take away  the  heat including  field  heat and  respiration heat  from the  post-harvest  vegetables in the first  time, this  heat is deadly  to keeping  the freshness
  • Cooling  is  very uniform.Vacuum cooling assures  uniform  cooling.There is  no temperature difference  between the leaves and the stalk  core. Freshness  and cleanliness are essential  features of vacuum  processing.
  • After being vacuum cooled, vegetables  have excellent freshness, color, flavor and nutritional components, and  can be  stored for a long time.
  • The vacuum cooling technique  is beneficial for removal of harmful  gases  and  killing  pests  so as to  increase  the shelf-life period  of vegetables.
  • No restriction to harvest.Green vegetables  can be picked at  any  time,since they can be cooled in only 20-30  minutes.
  • Optimization of yield.Since   only  about  2-3% of the water  is vaporised,there is no danger  of the vegetables drying  out or their  weight  being  reduced.
  • Harvesting in the rain is possible.The   water  clinging  to the surfaces of the vegetables is moved  in a vacuum, and there  is no damage during  transportation.Even some  vegetables  washed  in water  can be processed.
  • Can be cooled  in the  package. The vegetables  are delivered in a clean  package, maintaining their  original freshness and texture.There is no discolouration or other  changes.
  • Can do spray or sterilised treatment   inside  vacuum  chamber.
  • Can deliver/export   to distant  countries   under  cooling

Vacuum Cooling Process

Vacuum Cooling Catalog Download

Vacuum Cooling Catalog