Collection:
Juneau—Douglas City Museum
Object ID:
2007.22.140 A—H
Accession#:
2007.22
Credit Line:
Transferred from the U.S. Bureau of Land Management.
Object Name:
Furnace, Muffle
Title:
Muffle Furnace
Year Range from:
1950
Year Range to:
1996
Description:
Muffle Furnace
A. — Furnace: Includes the iron, front and rear face pieces, the sheet metal body, the heavy iron cap; four long threaded rods to hold the front and rear face pieces together, and two sections of "L—beam" that fit into the verticle lots on the inside of each face piece. The front face piece, with one shoulder strap, the door, and the removable shelf are on exhibit.

B. — Furnace Stand: Four legged steel stand to hold the muffle furnace. Attached to the back proper left leg is a steel bracket that is bolted to the leg and has a hole in the other end. This other end attaches to the blower when the whole unit is set up. The front two legs and cross piece are currently on exhibit in the gallery. Attached to the front proper left leg is the power box that turns the blower on and off.

C. — Blower. Mounted on the floor underneath the furnace. Attaches to the pipe which takes air to the nozzle. Apparatus consists of a steel stand designed to bolt to the floor. The stand has a table on it, to which is bolted an electric motor. The electric motor has a data plate on the front. The motor is a "Leland Motor" manufactured by general electric. The bottom 1/4 of the data plate has been obscured by paint. The blower itself is mounted to the proper right of the stand. It is round with a pipe coming forward off of the bottom. The pipe ends in a flat flange, with 4 square head bolts to attach it to an air line. In raised printing on the side of the blower is says: "THE DENVER FIRE CLAY CO / DENVER COLO / NO 200 / SERIAL NO." There is no serial number.

D. — Nozzle. The is nozzle attached on top of a heavy steel pipe. This pipe brings air from the blower to the nozzle tip. The pipe has a 90 degree bend in the bottom that ends in a face plate which attaches to the face plate on the blower. The bottom section of pipe between the bend and the face plate has been taken off and substituted with a modern piece so that the entire unit can be exhibited effectively. There is an oil line on the proper right side of the nozzle. This piece is on exhibit, except for the fragment of pipe which was removed and stored in the crate.

E. Vent hood — Triangular shaped vent hood, with a stove pipe at the top. Positioned above the furnace door. Attached to the front face plate of the furnace with two bolts. The stove pipe ran up and then back toward the main smoke stack where it entered at a 90 degree angle. Currently on exhibit in the gallery.

F. — Front vent Tile — large block of ceramic material meant to go into the square opening on the front of the muffle furnace cap.

G. — Rear Vent Tile — small block of ceramic material meant to go into the rectangular opeing on the proper left side of the furnace cap. This is actually the "muffle vent."

H. Molding Tool — Steel, bent into an arc. This was used to form the cement front of the furnace interior where the door fit.
Notes:
This muffle furnace was used to fire assay ore samples. It was used in the Assay Lab at the United States Bureau of Mines. See the document file for detailed paperwork about construction, erecting and maintenance of the machine. Ran on fuel oil.

Fuel to the muffle furnace was shut off for the last time on January 8, 1994.

Model #4411.
Search Terms:
T&E
Assaying
JMIC
Mining
Click to Enlarge
Muffle Furnace at BLMMuffle Furnace at BLM
Image 
Rear Vent TileRear Vent Tile
Molding Tool for doorwayMolding Tool for doorway
Molding Tool for DoorwayMolding Tool for Doorway