CARBON DIOXIDE CONTROLLER FOR A

CARBURIZING FURNACE

Carburizing Process

A steel part can be given a hard exterior layer by diffusing free carbon into its surface. The metallurgical process of diffusing carbon into steel is called carburizing. Carburizing is normally accomplished by subjecting the steel to a fairly high temperature, about 1700oF, for several hours in the presence of a carburizing atmosphere. Carburizing atmosphere is a mixture of normal combustion products with a specially manufactured gas. The manufactured gas contains heavy concentrations of carbon monoxide(CO) and carbon dioxide(CO2).

Figure 15-12Carburizing Furnace

The valve position is controlled by a system which compares the actual composition of the atmosphere to the desired composition. If the control circuitry finds any discrepancy between actual and desired composition, it adjust the valve opening accordingly.

Figure 15-13

Figure 15-13 represents the circuitry for measuring carbon dioxide (CO2) concentration. The waveforms at various points in the circuit are drawn in A through H.

Figure 15-14Carbon Dioxide

Figure 15-14 represents the physical appearance of the carbon dioxide (CO2) measurment transducer.

Figure 15-14

In letter C, it represents the face view of the infrared chopper. In letter D, it represents the face view of the LED chopper.

Measuring the CO2 Concentration

Figure 15-15Error Detection Circuitry

B C

Figure 15-15 represents the schematic diagram of the error-detection circuitry, the controller circuitry, and the final correcting device.

Leader: Alvin E. BondocMembers: Mari Faye Tolentino

Eljun Franzel Angeles Rachel Dela Cruz Richard Esguerra