Boiler blow down controller

A method of producing an output signal in response to only a predetermined relatively rapid change in the temperature of a boiler blow down means, comprising the steps of of detecting said temperature, transducing the detected temperature into an electrical signal, inputting said signal to circuit means, selecting said circuit means such that its time constant is proportional to said predetermined relatively rapid change in said temperature, and producing an output signal from said circuit means in response to said predetermined relatively rapid change in said temperature.

A method of monitoring the blown down condition of a boiler comprising the steps of sensing the temperature of the boiler blow down means, producing an electrical signal proportional to said sensed temperature, supplying said signal to circuit means, and selecting the values of the elements in said circuit means such that said circuit means will produce an output when said blown down means temperature undergoes a predetermined rapid change.

In combination with a boiler having blow down means, the improvement comprising an electrical device adapted to sense the temperature change in the blow down means caused by the blowing down operation and to produce a signal in response to such temperature change, timing means adapted to activate parts of the circuit at pre-determined times and for predetermined intervals of time, first and second alerting means;

• circuitry interconnecting said electrical device, said timing means and said first and second alerting means in such a manner that said first pre-determined on-time controlled by said timing means and said second alerting means are activated if said boiler is not blown down during said first pre-determined on-time, said circuitry further including means to hold said alerting means in an activated condition until a boiler blown down temperature change is sensed by said electrical device.