Tangentialy gas fired muffle

Patent · Tue May 09 04:00:00 EDT 1978

OSTI ID:6176207

Dohren, D G

England's Cooperheat has developed an improved apparatus for heat-treating a circumferentially welded joint between two pipe sections that overcomes the problem of hot spots created by flame impingement and makes possible the use of atmospheric burners previously thought unsuitable for this application. Because atmospheric burners require no blowers or compressors, the tangentially fired gas muffle is lighter in weight and relatively less expensive than conventional heating devices. The muffle, split and hinged for ease of assembly on a welded pipe joint, consists of an annular housing defining an outer annular chamber provided with tangential inlet ports in the form of immersion tubes, each containing an atmospheric gas burner. The outer annular chamber also has outlet ports, which are arranged to discharge the products of combustion of the preceding gas burner or burners. The annular housing also contains a ring of perforated or expanded material, such as expanded Inconel, which defines the inner annular wall of the first annular chamber and the outer annular wall of a second annular chamber. The second chamber is positioned, in use, adjacent to the walls of the welded pipe sections, so that the perforated or expanded metal ring is adjacent to the circumferential pipe weld. In this case, the products of combustion of the burners do not have to pass through the perforated or expandedmetal ring enroute to the outlet ports because both the inlet and the outlet ports are provided in the outer annular chamber. This reduces the fluidic impedance of the arrangement, thereby enabling the use of atmospheric gas burners. The ring acts as a radiant to dissipate heat uniformly onto the pipe surfaces and also prevents flame impingement onto the pipe surface by containing the combustion process in the first annular chamber.

• Assignee: Cooperheat
• Patent Number(s): US 4088439
• OSTI ID: 6176207
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
421000* -- Engineering-- Combustion Systems
ANNULAR SPACE
BURNERS
CHEMICAL REACTIONS
COMBUSTION
CONFIGURATION
DESIGN
EQUIPMENT
GAS BURNERS
HEAT TREATMENTS
JOINTS
OXIDATION
PIPES
SPACE
THERMOCHEMICAL PROCESSES
WELDED JOINTS