Vacuum Balloon: Inflated skin:
IdeasBank Memon
Reference 8548.       Class: GREEN

A vacuum balloon requires a rigid skin in order that the interior can be evacuated. However, sufficent rigidity can be obtained in the skin by constructing it of a double layer of flexible material which is kept under pressure.

In essence this is similar to the situation in an inflated vehicle wheel rubber innertube. Imagine the tube changed in shape from a circle to a sphere, with the inner and outer skins connected together at regular intervals by hot welding or fibre links.

Pressure of the ambient air is nominally 1 atmosphere. For the double-skin sphere to remain uncollapsed if the interior A was fully evacuated (0 atmospheres), the air pressure in the skin would need to be above 2 atmospheres.

This root memon is popped-up on this occasion for basic exposure. Very considerable further ramifications are possible.

INDICATIONS

  • The air pressure in a bicycle innertube is around 4 atmospheres.
  • Connection of the inner and outer skins could be achieved by many different methods.
  • The double skin could be replaced by a single skin supported by a network of inflated ribs. However the pressure within the ribs would need to be correspondingly higher.
  • The interior A need not be fully evacuated for the double-skin balloon to float, only enough air to compensate for the weight of the skins and the air between them need be withdrawn.
  • If a flexible balloon was constructed in collapsed form, the interior sealed while collapsed, and the double skin inflated, no evacuation pump would be needed as the interior would be largely free of air.

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