Steam heated shrink tunnel

An apparatus for shrinking film onto products moving along a conveyance path, comprising:

• an elongated steam chamber including an interior steam flow space along which steam travels, wherein the elongated steam chamber is shaped to form a shrink tunnel through which the conveyance path extends, wherein the elongated steam chamber includes tunnel facing walls that separate the interior steam flow space from the shrink tunnel, wherein the tunnel facing walls include inner surfaces facing and exposed to the shrink tunnel and outer surfaces facing and exposed to the interior steam flow space, wherein a steam input is provided for flowing steam into the interior steam flow space, wherein steam traveling within the interior steam flow space and in contact with the outer surfaces of the tunnel facing walls heats the tunnel facing walls, and the tunnel facing walls thereby radiate heat into the shrink tunnel, the interior steam flow space including output openings;
• steam pipes positioned at least partly within the shrink tunnel, each steam pipe extending along at least part of a length of the shrink tunnel, each steam pipe separated from the interior steam flow space by the tunnel facing walls, each steam pipe including steam ejection orifices for ejecting steam into the shrink tunnel;
• and
• a plurality of steam flow tubes, each steam flow tube connected to feed steam from one of the output openings of the interior steam flow space to one of the steam pipes, each steam flow tube running outside of the shrink tunnel;
• wherein the interior steam flow space functions as a steam manifold through which steam progresses to reach the output openings.

An apparatus for shrinking film onto products moving along a conveyance path, comprising:

• an elongated steam chamber including an interior steam flow space along which steam travels, wherein the elongated steam chamber is shaped to form a shrink tunnel through which the conveyance path extends, wherein the elongated steam chamber includes at least one tunnel bounding wall that separates the interior steam flow space from the shrink tunnel, wherein the at least one tunnel bounding wall includes an inner surface facing and exposed to the shrink tunnel and an outer surface facing and exposed to the interior steam flow space, wherein a steam input is provided for flowing steam into the interior steam flow space, wherein steam traveling within the interior steam flow space and in contact with the outer surface of the at least one tunnel bounding wall heats the at least one tunnel bounding wall, and the at least one tunnel bounding wall thereby radiates heat into the shrink tunnel, the interior steam flow space including at least one outlet opening;
• at least one steam header positioned at least partly within the shrink tunnel and extending along at least part of a length of the shrink tunnel, the steam header including steam ejection orifices for ejecting steam into the shrink tunnel;
• and
• at least one steam flow tube connected to feed steam from the at least one outlet opening of the interior steam flow space to the at least one steam header.