US1785549A - Open-hearth regenerative furnace - Google Patents

Description

Dec. '16, 1930. J. o. GRIGGS 1,785,549

OPEN HEARTH REGENERATIVE FURNAGE Filed April l. 192.9

Patented Dec. 16, 1930 UNITED STATES JOHN o. GRIGGS, or STEUBENVILLE, oHIo OPEN-HEARTH REGENERATIVE FURNACE Application iilea April 1, 1929. serial No. 351,490.

ciency and reduced melting time, and which reduces construction costs, as compared with prior regenerative open hearth furnaces.

The preferred embodiment of the invention is shown in the accompanying drawings in which F ig. l is a section taken longitudinally of one end of the furnace; and Fig. 2

is a horizontal section taken on line II--II,`

Fig. 1.

This invention is applicable to open hearth regenerative furnaces which are provided at each end with a horizontally disposed gas port, an air port above the gas port, and passages for conducting gas and air to the respective ports, these passages usually leading from gas and air slag pockets. In accordance with the invention, each end is provided with a by-pass conduit leading from the air supply to the bottom of the gas port anterior of its outlet to the furnace, and the bottom of the gas port adjacent to but anterior of the outlet of the by-pass conduit is provided with an upwardly extending baffle. This construction gives a type of Venturi action, as a result of which there is' produced a uniform flow of air from the bypass conduit, the flow of gas regulates the flow of'air, and thorough mixing and highly efficient combustion result.

In the drawings, there is shown one end of a conventional open hearth regenerative furnace comprising a hearth l, end wall 2, roof 3, and gas and air slag pockets 4 and 5 respectively, connected to regenerator chambers containing checkerwork, not shown, and

it will be understood that the construction of the opposite end of the furnace is similar to that shown and described here. An uptake 6 conducts gas from slag pocket 4 to a i gas port 7 whose outlet communicates with the furnace, and air is passed from slag pocket 5 through uptake 8 to an air port 9 above the gas port. The gas and air ports are separatedby an arch 10 extending forwardly from end wall 2, and the arch may be water-cooled in any suitable manner. Air from s'lag pocket 5 is also passed to the gas port through a by-pass conduit l1,\and, in accordance with the invention, this by-` pass opens into the bottom of the gas portl at a point anterior of its outlet to the furnace. The bottom of the gas port adjacent the outlet of, but anteriorto, the by-pass conduit is iprovided with an upwardly extending ba e. This construction is preferably accomplished in the manner shown in Fig. 1 by extending the gas port bottom 12 between uptake 6 and by-pass l1, above the plane of the bottom 13 of the forward portion of the gas port. The outlets of uptake 6 and by-pass 11 being disposed in the bottom of the gas port, the outlet of the by-pass is in a plane parallel to but below that of uptake 6, and in this mannerthere is provided anozzle passage similar to a Venturi tube, the partition Wall forming the throat. In the use of furnaces having burners con.- structed in accordance with the invention, the static head of gas from the rear portion of the gas port is converted to a velocity so head as the gas flows through the throat portion. Suction is thus created in the air by-pass conduit, and by virtue of this Venturi v nozzle action, the flow of air to the gas port is proportioned by that of the gas, making regulation of the flame at different stages of the melt readily possible, and preventing back flow of gas into the by-pass conduit. In the forward portion of the gas port the gas again assumes a static head, alld this enlarged portion also takes care of any increase in gas volume due to combustion.

In prior furnaces which are commercially practical, air for combustion is taken from the air port above the gas port, and because this air is cooled by infiltration through the walls and roof, the flame temperature is lowered. Furthermore, there is an inadequate mixture of the air with the gas, resulting in incomplete combustion and in a longer flame than desirable for high eiciency. With the construction provided by this invention, the draft created in by-pass conduit 11 supplies a substantial proportion of air at an initially high temperature, and a. smaller proportion of air cooled by infiltration than in prior furnaces. This, together with the very lthorough mixing caused by the nozzle action, cmbines to give a higher flame temperature than in prior furnaces; y

The thorough mixing of gas With highly heated air givessubstantially complete combustion in the vicinity of the gas port outlet, so that the furnace operates With a short flame, reducing cutting out of the brickwork at the opposite end of the furnace. Likewise, because of the production of a hotter flame than heretofore, the melting time is decreased, and this with more eicient combustion, reduces fuel consumption and operating costs. Also, the invention provides a simple and inexpensive construction at the burner ends of the furnaces. l

According to the rovisions of the Patent Statutes, I have eXp ained the principle and mode o'f operation o f my invention, and have described what I now consider to represent its best embodiment. However, I desire to have it understood that, Within the scope of the appended claim the invention may be practiced otherwise than as specifically described.

I claim as my invention:

An open hearth regenerative furnace provided at each end With a horizontally disposed gas port, an air port above the gas port, passages for conducting gas and air to said ports, and a by-pass conduit leading from said air passage to the bottom of said gas port at a point anterior of its outlet, the bottom of said gasort adjacent to but anterior of the outlet o said by-pass being provided With an upwardly extending baiile to.

cause uniform How of air from the by-pass into the gas port.

In testimony whereofI sign my name.

J PDT O. GRIGGS.

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