Immersion heater

Claim 1

Electrical liquid heating apparatus for rapid heating of small unit volumes of liquid and comprising: a unit volume liquid container having sidewalls, a bottom and a top; upper wall means having a predetermined height defining a liquid well on the upper surface of said container top; at least one tubular conduit fastened to said container top and having one end open to said well, below said predetermined height and the other end opening into said container adjacent the bottom thereof for conducting liquid from said well downwardly into said container and delivering the same adjacent the bottom thereof; electrical heating element means supported within said container and extending around the same adjacent the upper end thereof; a plurality of liquid passageways connected to said container top and communicating between said container and said well, heating of said liquid in said container by said heating element producing displacement of liquid upwardly through said liquid passageways into said well for subsequent recirculation downwardly through said conduit into the lower end of said container; a housing sealed around and enclosing said container and said liquid well means thereon and defining a jacket surrounding the same for containing additional liquid outside said unit volume container and communicating with said container only through said liquid well for passage of said liquid therein from said housing; inlet means for introducing liquid within said housing, and, outlet means for connecting said housing to any suitable conduit for removing liquid from said housing and container.