US Patent 11920878 Continuous helical baffle heat exchanger

A heater includes a flow guide and electrical resistance heating elements. The flow guide defines a continuous geometric helicoid disposed about a longitudinal axis and defines perforations that extend in a longitudinal direction through a first longitudinal length of the geometric helicoid. The first longitudinal length is less than a full longitudinal length of the geometric helicoid. The electrical resistance heating elements extend through the perforations. For each electrical resistance heating element, a length of that electrical resistance heating element and a pitch of the geometric helicoid at a distal end of that electrical resistance heating element are such that the distal end of that electrical resistance heating element is a distance X from the geometric helicoid at the distal end of that electrical resistance heating element. The distance X is less than or equal to 40% of the pitch at the distal end of that electrical resistance heating element.