Flange Shields For Furnaces

: The Working Of Steel

Such portable flame shields as the

one illustrated in Fig. 106 may prove serviceable before furnaces

required for plate work, where the doors are often only opened

for a moment at a time. This shield can be placed far enough in

front of the furnace, that it will be possible to work under it

or around it, in removing bulky work from the furnace, and yet

it will afford the furnace tender some relief from the excessive
glare that will come out the wide-opened door. To have this shield

of light weight so that it may be readily pushed aside when not

wanted, the frame may be made up of pipe and fittings, and a piece

of thin sheet steel fastened in the panel by rings about the frame.

About the most disagreeable task in a heat-treating shop is the

removal of the pots from the case-hardening furnaces; these must

be handled at a bright red heat in order that their contents may be

dumped into the quenching tank with a minimum-time contact with the

air, and before they have cooled sufficiently to require reheating.

Facing the heat before the large open doors of the majority of

these furnaces, in a man-killing task even when the weather is

moderately cool. The boxes soon become more or less distorted,

and then even the best of lifting devices will not remove a hot

pot without several minutes labor in front of the doors.

In Fig. 107 is shown a method of arranging a shield on one type of

charging and removing truck. This shield cannot afford more than

a partial protection to the body of the furnace tender, because

he must be able to see around it, and in some cases even push it

partly through the door of the furnace, but even small as it is it

may still afford some welcome protection. The great advantage in

this case of having the shield on the truck instead of stationary

in front of the furnace, is that it still affords protection as

long as the hot pot is being handled through the shop on its way

to the quenching tank.

It might be interesting to many engaged in the heat-treating or

case hardening of steel parts, to make a special note of the design

of the truck that is illustrated in connection with the shield;

the general form is shown although the actual details for the

construction of such a truck are lacking; these being simple, may be

readily worked out by anyone wishing to build one. This is considered

to be one of the quickest and easiest operated devices for the

removal of this class of work from the furnace. To be sure it may

only be used where the floor of the furnace has been built level

with the floor of the room, but many of the modern furnaces of

this class are so designed.

The pack-hardening pots are cast with legs, from two to three inches

high, to permit the circulation of the hot gases, and so heat more

quickly. Between these legs and under the body of the pot, the two

forward prongs of the truck are pushed, tilting the outer handle

to make these prongs as low as possible. The handle is then lowered

and, as it has a good leverage, the pot is easily raised from the

floor, and the truck and its load rolled out.