Heat exchanger plate and a fill pack of heat exchanger plates

A fill pack, comprising:

• a plurality of corrugated sheets of stiff material, sequential ones of the plurality of corrugated sheets being facially opposed to each other and connected together, each corrugated sheet of stiff material configured in a repetitive series of elongated corrugations and having a front side surface and a rear side surface disposed opposite the front side surface, each corrugation having a first corrugation segment, a second corrugation segment disposed offset from and extending parallel to the first corrugation segment and an intermediate corrugation segment disposed between and interconnecting the first corrugation segment and the second corrugation segment in a continuous, uninterrupted manner, the intermediate corrugation segment extending obliquely relative to the first corrugation segment and the second corrugation segment to form a continuous, uninterrupted offset corrugation,
• wherein connected ones of the plurality of corrugated sheets are connected in a manner that the front side surfaces are facially opposed to each other while the rear side surfaces are facially opposed to each other and
• wherein each one of the intermediate corrugation segments has an intermediate corrugation segment ridgeline and a recessed surface portion defining a recess located at and formed into the intermediate corrugation segment ridgeline such that the connected ones of the plurality of corrugated sheets are received in facially-opposing ones of the recesses and connected at respective ones of the recessed surface portions.