Liquid level control

A liquid level control system for liquid containment vessels and the like having heating means associated therewith for heating the liquid contained therein, said system comprising, in combination:

• control means;
• sensing means associated with said vessel for detecting the presence or absence of liquid at an established height in said vessel and for generating a control signal which is coupled to said control means;
• valve means for controlling the feeding of liquid into said vessel;
• delay means for controlling the operation of said heating means;
• said valve means and said delay means being coupled to said control means and controlled by said control means in accordance with the control signal generated by said sensing means;
• the operation being such that said valve means is operated to feed liquid into said vessel when said sensing means detects the absence of liquid at the established height in said vessel and to operate said valve means to cut off the feed of liquid into said vessel when said sensing means detects the presence of liquid at the established height in said vessel, and such that said delay means is operated to cut off said heating means when said sensing means detects the absence of liquid at the established height in said vessel for an established time period.