Recovery of combustible gases from furnaces in general and more particularly from converters

Claim 2

A plant for the recovery of combustible gases issuing from the mouth of furnaces in general and more particularly of converters comprising: - an exhaust conduit having an inlet end and an outlet end, with said inlet end being disposed above the furnace mouth to collect combustible gases issuing therefrom; - a combustion chamber separate from said exhaust conduit with the outlet end of said exhaust conduit opening into said chamber; - an auxiliary air conduit having an annular inlet located around the inlet of said exhaust conduit above the furnace mouth to withdraw ambient air from the perimeter of said mouth, and an outlet end opening into said combustion chamber to supply same with comburent air to cause combustion of said combustible gases within said combustion chamber, thus producing burnt gases therein; - means to discharge outwardly said burnt gases from said combustion chamber; - gas propelling means to cause said combustible gases to flow through said exhaust conduit into said combustion chamber and said burnt gases from same to said discharge means; - air propelling means to cause air to flow through said auxiliary air conduit into said combustion chamber; - said gas propelling means comprising a first blower having its low pressure side connected with said combustion chamber; - and said air propelling means being formed of a seCond blower disposed in said auxiliary air conduit.

Claim 3

A plant for the recovery of combustible gases issuing from the mouth of furnaces in general and more particularly of converters comprising: - an exhaust conduit having an inlet end and an outlet end, with said inlet end being disposed above the furnace mouth to collect combustible gases issuing therefrom; - a combustion chamber separate from said exhaust conduit with the outlet end of said exhaust conduit opening into said chamber; - an auxiliary air conduit having an annular inlet located around the inlet of said exhaust conduit above the furnace mouth to withdraw ambient air from the perimeter of said mouth, and an outlet end opening into said combustion chamber to supply same with comburent air to cause combustion of said combustible gases with said combustion chamber, thus producing burnt gases therein; - means to discharge outwardly said burnt gases from said combustion chamber; - gas propelling means to cause said combustible gases to flow through said exhaust conduit into said combustion chamber and said burnt gases from same to said discharge means; - air propelling means to cause air to flow through said auxiliary air conduit into said combustion chamber; - an annular gas recycling duct disposed between the inlet end of said exhaust conduit and the annular inlet of said auxiliary air conduit, said duct also opening above the furnace mouth; - and means to introduce into said duct a portion of the burnt gases from said combustion chamber to form an inert annular gaseous screen between the combustible gases issuing from the furnace mouth and the ambient air withdrawn by the annular inlet of said auxiliary air conduit.

Claim 4

A plant for the recovery of combustible gases issuing from the mouth of furnaces in general and more particularly of converters comprising: - an exhaust conduit having an inlet end and an outlet end, with said inlet end being disposed above the furnace mouth to collect combustible gases issuing therefrom; - a combustion chamber separate from said exhaust conduit with the outlet end of said exhaust conduit opening into said chamber; - an auxiliary air conduit having an annular inlet located around the inlet of said exhaust conduit above the furnace mouth to withdraw ambient air from the perimeter of said mouth, and an outlet end opening into said combustion chamber to supply same with comburent air to cause combustion of said combustible gases with said combustion chamber, thus producing burnt gases therein; - means to discharge outwardly said burnt gases from said combustion chamber; - gas propelling means to cause said combustible gases to flow through said exhaust conduit into said combustion chamber and said burnt gases from same to said discharge means; - air propelling means to cause air to flow through said auxiliary air conduit into said combustion chamber; - an annular gas recycling duct disposed between the inlet end of said exhaust conduit and the annular inlet of said auxiliary air conduit, said duct also opening above the furnace mouth; - and means to introduce into said duct a portion of the burnt gases from said combustion chamber to form an inert annular gaseous screen between the combustible gases issuing from the furnace mouth and the ambient air withdrawn by the annular inlet of said auxiliary air conduit.

Claim 5

In a plant as claimed in claim 1 for a furnace tiltable between a loading position, a blowing position and a pouring position: - a first auxiliary hood disposed above the mouth of the furnace when same is at its loading position; - a second auxiliary hood disposed above the mouth of the furnace when same is at its pouring position; - the inlet of said exhaust conduit being disposed above the mouth of the furnace when same is at its blowing position; - and valve means to selectively connect said auxiliary air conduit respectively with the annular inlet of same, with said first auxiliary hood or with said second auxiliary hood.

Claim 6

A plant for the recovery of combustible gases issuing from the mouth of furnaces in general and more particularly of converters comprising: - an exhaust conduit having an inlet end and an outlet end, with said inlet end being disposed above the furnace mouth to collect combustible gases issuing therefrom; - a combustion chamber separate from said exhaust conduit with the outlet end of said exhaust conduit opening into said chamber; - an auxiliary air conduit having an annular inlet located around the inlet of said exhaust conduit above the furnace mouth to withdraw ambient air from the perimeter of said mouth, and an outlet end opening into said combustion chamber to supply same with comburent air to cause combustion of said combustible gases within said combustion chamber, thus producing burnt gases therein; - means to discharge outwardly said burnt gases from said combustion chamber; - gas propelling means to cause said combustible gases to flow through said exhaust conduit into said combustion chamber and said burnt gases from same to said discharge means; - and air propelling means to cause air to flow through said auxiliary air conduit into said combustion chamber; said exhaust conduit being formed with at least one bent portion having a radius of curvature and being double walled to define a cooling water jacket, with the width of said water jacket being substantially inversely proportional to the radius of curvature of said bent portion, and said plant further comprising means to inject water tangentially into said water jacket.

Claim 7

A plant for the recovery of combustible gases issuing from the mouth of furnaces in general and more particularly of converters comprising: - an exhaust conduit having an inlet end and an outlet end, with said inlet end being disposed above the furnace mouth to collect combustible gases issuing therefrom; - a combustion chamber separate from said exhaust conduit with the outlet end of said exhaust conduit opening into said chamber; - an auxiliary air conduit having an annular inlet located around the inlet of said exhaust conduit above the furnace mouth to withdraw ambient air from the perimeter of said mouth, and an outlet end opening into said combustion chamber to supply same with comburent air to cause combustion of said combustible gases within said combustion chamber, thus producing burnt gases therein; - means to discharge outwardly said burnt gases from said combustion chamber; - gas propelling means to cause said combustible gases to flow through said exhaust conduit into said combustion chamber and said burnt gases from same to said discharge means; - and air propelling means to cause air to flow through said auxiliary air conduit into said combustion chamber; said exhaust conduit being formed with at least one bent portion having a radius of curvature and being double walled to define a cooling water jacket, with the width of said water jacket being substantially inversely proportional to the radius of curvature of said bent portion, and said plant further comprising means to inject water tangentially into said water jacket.

Claim 8

A plant for the recovery of coMbustible gases issuing from the mouth of furnaces in general and more particularly of converters, comprising: - means to withdraw the combustible gases above the furnace mouth; - means to withdraw ambient air from the perimeter of the furnace mouth; - means to mix said gases and said air in a separate combustion chamber to cause combustion of said combustible gases within said combustion chamber, thus producing burnt gases; - means to discharge outwardly said burnt gases from said combustion chamber; and means to derive a portion of said burnt gases from said combustion chamber and to form with said derived burnt gases an inert gaseous screen around said combustible gases as same issue from said furnace to isolate said combustible gases from ambient air.

Claim 9

A plant for the recovery of coMbustible gases issuing from the mouth of furnaces in general and more particularly of converters, comprising: - means to withdraw the combustible gases above the furnace mouth; - means to withdraw ambient air from the perimeter of the furnace mouth; - means to mix said gases and said air in a separate combustion chamber to cause combustion of said combustible gases within said combustion chamber, thus producing burnt gases; - means to discharge outwardly said burnt gases from said combustion chamber; and means to derive a portion of said burnt gases from said combustion chamber and to form with said derived burnt gases an inert gaseous screen around said combustible gases as same issue from said furnace to isolate said combustible gases from ambient air.