Apparatus, system and method for heating fluid from a plurality of fluid sources. A heating chamber top portion includes a plurality of fluid inlet tubes configured to pass fluid from the plurality of fluid sources. A heating chamber may be coupled to the heating chamber top portion, the heating chamber collectively receives at least some of the fluid from the plurality of fluid sources. At least one heating element configured within the heating chamber heats the received fluid from the plurality of fluid sources. An agitator mixes the received fluid from the plurality of fluid sources in the heating chamber, wherein the agitator is configured to mix the received fluid from the plurality of fluid sources by rotationally turning within the heating chamber.

A kneading apparatus has a housing and first and second rotary shafts mounted in the housing in parallel to one another for undergoing rotation about respective axes in opposite directions at unequal speeds to one another for kneading an object. The first and second rotary shafts have respective first and second stirring members arranged helically at a predetermined helical pitch and at predetermined angular pitch intervals, with the second stirring members being arranged with an inverse helix from that of the first stirring members. Side blocking plates disposed in the housing partially block the kneaded object and move it between the first and second rotary shafts. The side blocking plates are spaced apart from one another to provide a space above the first and second rotary shafts such that the kneaded object can pass through the space in the axial direction of the first and second rotary shafts.