Method and apparatus for monitoring unburned particulate accumulation in the exhaust duct of a combustion system

Apparatus for monitoring the accumulation of particulates on the lining of an exhaust duct or the like associated with a combustion device, comprising:

• means for sensing the temperature within the duct including means for converting the sensed temperature to an electrical signal proportional in magnitude to said temperature;
• means for detecting when the magnitude of said signal is within first and second ranges respectively corresponding to first and second flue temperature ranges;
• first means responsive to said detecting means for generating a count corresponding to the time interval that the magnitude of said signal is within said firstrange thereof;
• means responsive to said first means for providing a perceivable indication of when said count reaches a prescribed value, said prescribed value being proportional to an accumulation of particulates on said duct;
• second means responsive to said detecting means for generating a count corresponding to the time interval that the magnitude of said signal is within said second range thereof;
• and,
• means controlled by said second means for resetting the count of said first means when the count of said second means reaches a preselected value.

A method of monitoring the accumulation of unburned particulates within an exhaust device associated with a combustor, such as the flue lining of a stove flue, comprising the steps of:

• (A) sensing the temperature within said flue lining;
• (B) measuring the time during which the sensed temperature is within a first temperature range in which particulates accumulate on said flue lining;
• and
• (C) automatically providing a perceivable warning when the measured time reaches a preselected value.

A method of monitoring the accumulation of unburned particulates within the exhaust system of a combustion device, comprising the steps of:

• (A) sensing the temperature within said exhaust system;
• (B) converting the temperature sensed in step (A) to an electrical signal which varies in magnitude in accordance with changes in said temperature;
• (C) measuring the level of said electrical signal;
• (D) producing digital pulses when the magnitude of said electrical signal falls within either first or second ranges;
• (E) accumulating a count of the number of digital pulses when said signal is within said first range thereof;
• (F) activating a warning device when the count accumulated in step (E) reaches a preselected value;
• (G) accumulating a count of the number of digital pulses when said signal is within said second range thereof;
• (H) releasing the count accumulated in step (E) when the count accumulated in step (G) reaches a prescribed value.

Apparatus for monitoring the accumulation of particulates on the lining of an exhaust duct or the like for a combustion device, comprising:

• means for sensing the temperature within said exhaust duct;
• means for generating an electrical signal correlated to the duration of time that said temperature is within a first temperature range wherein particulates accumulate on said lining;
• and
• means coupled with said generating means for producing an indication of when said electrical signal reaches a preselected value corresponding to a prescribed accumulation of particulates on said lining.