Intelligent oxygen level controller for biofuel-fired burner

An intelligent controller for monitoring an exhaust path that is disposed downstream of a fire box for containing a bio-fuel fire, and for controlling an air handler that supplies air to the fire box, the exhaust path, the fire box and the air handler being components of a bio-fuel fired device, the bio-fuel fired device further including a catalytic converter disposed within the exhaust path downstream of the fire box and configured to combust unburned material from the bio-fuel fire, a first oxygen level sensor disposed in the exhaust path upstream of the catalytic converter, and a second oxygen level sensor disposed in the exhaust path downstream of the catalytic converter, the intelligent controller comprising:

• a first port configured to be coupled to the first oxygen level sensor in order to receive from the first oxygen level sensor a first signal indicating a level of oxygen in exhaust gas upstream of the catalytic converter;
• a second port configured to be coupled to the second oxygen level sensor in order to receive from the second oxygen level sensor a second signal indicating a level of oxygen in the exhaust gas downstream of the catalytic converter;
• a third port configured to send command signals to the air handler that supplies air to the fire box;
• and
• a processor coupled to the first, second, and third ports and configured to automatically:
• repeatedly receive, via the first port, the first signal,
• thereby receiving a series of first oxygen level values via the first port;
• and
• for each first oxygen level value of at least some of the series of first oxygen level values:
• compare the first oxygen level value to a first predetermined value;
• and
• when, as a result of the comparison, the first oxygen level value is found to be less than the first predetermined value:
• generate a first control signal configured to cause the air handler to increase the rate at which the air handler supplies air to the fire box;
• and
• send, via the third port, the first control signal to the air handler;
• the processor being further configured to automatically:
• repeatedly receive, via the second port, the second signal, thereby receiving a series of second oxygen level values via the second port;
• and
• for each second oxygen level value of at least some of the series of second oxygen level values:
• compare the second oxygen level value to a second predetermined value that is less than the first predetermined value;
• and
• when, as a result of the comparison, the second oxygen level value is found to be less than the second predetermined value:
• generate a second control signal configured to cause the air handler to increase the rate at which the air handler supplies air to the fire box;
• and
• send, via the third port, the second control signal to the air handler.