Gas Consumption For Carburizing
:
CASE-HARDENING OR SURFACE-CARBURIZING
:
The Working Of Steel
Although the advantages offered by the gas-fired furnace for carburizing
have been generally recognized in the past from points of view as
close temperature regulation, decreased attendance, and greater
convenience, very little information has been published regarding
the consumption of gas for this process. It has therefore been a
matter of great difficulty to obtain authentic information upon
this point, either from
akers or users of such furnaces.
In view of this, the details of actual consumption of gas on a
regular customer's order job will be of interest. The Revergen
furnace, manufactured by the Davis Furnace Company, Luton, Bedford,
England, was used on this job, and is provided with regenerators
and fired with illuminating gas at ordinary pressure, the air being
introduced to the furnace at a slight pressure of 3 to 4 in. water
gage. The material was charged into a cold furnace, raised to 1,652 deg.F.,
and maintained at that temperature for 8 hr. to give the necessary
depth of case. The work consisted of automobile gears packed in
six boxes, the total weight being 713 lb. The required temperature
of 1,652 deg.F. was obtained in 70 min. from lighting up, and a summary
of the data is shown in the following table:
Cubic Foot Total
Per Pound Number of
of Load Cubic Foot
Gas to raise furnace and charge from
cold to 1,652 deg.F., 70 min. 1.29 925
Gas to maintain 1,652 deg.F. for 1st hour 0.38 275
Gas to maintain 1,652 deg.F. for 2nd hour 0.42 300
Gas to maintain 1,652 deg.F. for 3rd hour 0.38 275
Gas to maintain 1,652 deg.F. for 4th hour 0.42 300
Gas to maintain 1,652 deg.F. for 5th hour 0.49 350
Gas to maintain 1,652 deg.F. for 6th hour 0.49 350
Gas to maintain 1,652 deg.F. for 7th hour 0.45 325
Gas to maintain 1,652 deg.F. for 8th hour 0.45 325
The overall gas consumption for this run of 9 hr. 10 min. was only
4.8 cu. ft. per pound of load.