US 3,969,932 A · Method and apparatus for monitoring the activity of catalytic reactors

Abstract

The inlet and outlet ends of a catalytic reactor are instrumented with oxygen sensors. A change of the fuel-air concentration of the combustible mixture is indicated by a jump in the output voltage of the sensors; the voltage of the inlet sensor changes before that of the outlet sensor and the greater the time difference between these changes, the higher is the catalytic activity of the reactor. When a repeatable and constant engine condition is reached, the fuel-air mixture is abruptly changed and an electronic circuit enables a logical circuit which controls a signal lamp. If, during a predetermined time interval, the outlet sensor also changes its output voltage, indicating a time difference which is too short, the warning signal is energized and the operator is alerted to the insufficient level of reactor activity.

Claims11

Dependent claims

A method for monitoring the activity of a catalytic reactor used in association with an internal combustion engine with fuel control, comprising the steps of:

A. providing an exhaust gas composition sensor at the inlet and at the outlet of said catalytic reactor;
B. finding a predetermined operational state of said internal combustion engine;
C. initiating a change of the output signals of said exhaust composition sensors;
and
D. measuring the time delay between the occurrence of the change of output signals from said exhaust composition sensors;
said time delay being an indicaton of the activity of said catalytic reactor.

3 more elements

An apparatus for monitoring the activity of a catalytic reactor, used in association with an internal combustion engine, said engine including a fuel control system, an exhaust system, and an air flow meter, said apparatus comprising:

A. a first exhaust gas composition sensor, located in the exhaust system of the internal combustion engine, upstream of said catalytic reactor;
B. a control amplifier, including a first threshold switch and an integrating circuit, whose input is connected to said first exhaust gas composition sensor;
and whose output is connected to said fuel control system;
C. a second exhaust gas composition sensor, located in the exhaust system of the internal combustion engine, downstream of said catalytic reactor;
D. a second threshold switch, whose input is connected to said second exhaust gas composition sensor;
E. a signal comparator and timing circuit whose inputs are connected to the outputs from said first and second threshold switches;
and
F. transducer means, located on said internal combustion engine for sensing and delivering an electrical output signal representative of an operational parameter of said engine, said electrical output signal being connected to said signal comparator and timing circuit.

5 more elements

Dependencies are inferred from the claim text.

Method and apparatus for monitoring the activity of catalytic reactors

Life of this patent

Method and apparatus for monitoring the activity of catalytic reactors

Life of this patent

Abstract

Claims11