Calvin C Blackman

US Patent:

48676756, Sep 19, 1989

Filed:

Jun 15, 1988

Appl. No.:

7/206716

Inventors:

Calvin C. Blackman - Vermilion OH

International Classification:

F27D 500
F27B 504

US Classification:

432 5

Abstract:

A method and apparatus for vacuum purging bell type furnaces is provided. A vacuum shell unit is provided which is removably emplacible over the inner cover of the furnace and has a vacuum tight seal to the base. A vacuum is pulled both within the inner cover and within the vacuum shell to remove the ambient gas. Nitrogen is then introduced into the inner cover and within the vacuum shell. The vacuum shell is then removed and purging continues within the inner cover either with nitrogen or other desired atmosphere gas, and finally furnace is emplaced over the inner cover to heat treat the work in a conventional manner.

US Patent:

40380220, Jul 26, 1977

Filed:

Jun 9, 1975

Appl. No.:

5/585218

Inventors:

Calvin C. Blackman - Vermilion OH

International Classification:

F23D 1144

US Classification:

431166

Abstract:

A recuperator which is disposed inside a furnace to utilize the heat in the products of combustion to preheat the air before it is introduced into the burner for combustion is disclosed. The recuperator has means to collect the products of combustion and cause them to flow from the furnace and air conducting means positioned to draw air externally from the furnace for supply to the burner disposed in heat exchange relationship with the collecting means whereby to heat the air within the furnace.

US Patent:

49647989, Oct 23, 1990

Filed:

Jun 12, 1989

Appl. No.:

7/351198

Inventors:

Calvin C. Blackman - Vermilion OH

International Classification:

F16K 100
F27B 904

US Classification:

432 23

Abstract:

A method and apparatus for vacuum purging bell type furnaces is provided. A vacuum shell unit is provided which is removably emplacible over the inner cover of the furnce and has a vacuum tight seal to the base. A vacuum is pulled both within the inner cover and within the vacuum shell to remove the ambient gas. Nitrogen is then introduced into the inner cover and within the vacuum shell. The vacuum shell is then removed and purging continues within the inner cover either with nitrogen or other desired atmosphere gas, and finally furnace is emplaced over the inner cover to heat treat the work in a conventional manner.