US2115613A

US2115613A - Reversible regenerative furnace

Info

Publication number: US2115613A
Application number: US143173A
Authority: US
Inventors: Brooke Joseph Blake Rowley
Original assignee: John Lysaght Australia Pty Ltd
Current assignee: John Lysaght Australia Pty Ltd
Priority date: 1936-10-15
Filing date: 1937-05-17
Publication date: 1938-04-26
Anticipated expiration: 1955-04-26

Description

p l 1933- J. B. R. BROOKE 1 2,115,613

REVERSIBLE REGENERATIVE FURNACE Filed May 17, 1937 3 Sheets-Sheet l 5 nws/vme f3 1?. Beau/r5 igu A7709 V April 26, 1938.' 5 R BRQOKE 2,115,613

' REVERSIBLE REGENERATIVE FURNACE Filed May 17, 1957 5 Shets-Sheet 2 Fig. 2'. 6/

mws/vroe April 1938- J. B. R. BROOKE 2,115,613

REVERS IBLE REGENERATIVE FURNACE Filed May 17, 19 57 5 Sheets-Sheet 3 INVENTOR T A5. 19. Bfiaam r BY ATTUP/VEY Patented Apr. 26, 1938 UNITED STATES PATENT OFFICE REVERSIBLE REGENERATIVE FURNACE Application May 17, 1937, Serial No. 143,173 In Great Britain October 15, 1936 9 Claims.

This invention relates to reversible regenerative furnaces having at each side gas and air regenerator' chambers which are in communication with gas and air inlet passages terminating in 5 ports through which gas and air are delivered to the furnace; In an open hearth steel furnace, to which the invention is particularly applicable, it is important that a correct mixture of air and gas'should be obtained and that the flame should be so directed that as much as possible of the heat serves to heat up the steel bath. In order 'tomaintain the direction of the flame throughout the life of the furnace it is more important that the size and shape of the gas port should be' maintained than the size and shape of the air port, because I have found that the dimensions of the air port can be considerably altered without materially affecting the shape or direction of the flame. Now, in normal practice, the g ratio of the area of the air port to that of the gasport lies between :1 and :1. As it is important thatthe gas should be preheated to a temperature approximately equal to that of the air, it-Will be clear that the quantity of destructive waste gases that pass through the gas ports on the way to the gas regenerator chambers must be far greater in proportion to the area of the gas ports than is the case with the airports, so that there is always a tendency for the gas ports to wear away or to clog up, as the case may be, more quickly than the air ports. This disadvantage is particularly apparent when the furnaces are fired by coke oven and blast furnace gas, because in such a case a higher degree of preheating of the gas is necessary and therefore more of the waste gases must be drawn through the gas port than is the case when producer gas is used.

A-number of proposals have been made with the object of reducing the amount of gas passing through the gas port at the side at which the gas.

leaves the furnace. In some cases by-pass connections have been provided between the front of the gas port and the back of it so that some of the outgoing gas can flow around the gas port. In otherproposals two valves have been provided, one to shut off the gas port and the other to open a by-pass connection from the front of the gas port to the passage leading to the gas regentJ crating chamber. The construction of such bypass connections necessitates a departure from thenormal furnace construction and thus is undesirable. Thus, in particular, instead of there being merely the gas and air ports through which so the gas and air flow in at each side of the furnace there are also ports constituting the openings' of the by-pass connections.

The present invention aims primarily at retaining essentially the standard port construction and yet preventing any gas from passing through the gas port at the side at which the gas leaves the furnace.

I provide a connection between points in the air inlet passages and the gas inlet passages respectively, together with means for opening this connection and simultaneously preventing the passage of gas through the gas port at the outlet side at each reversal of the furnace. It will be appreciated that with this construction there is no necessity to provide any additional ports other than those through which the air and gas enter the furnace and in fact all the gas that leaves the furnace must leave through the air port or ports. The connection in question can take the form of a very simple passage which can be made through the brickwork of an existing furnace.

By employing the construction just described, a single valve member may be employed to close the gas port at the outlet side and simultaneously to open the connection by which gas flowing from the furnace through the air port can pass to the gas regenerating chamber.

The connection described above may be made much larger in area than the gas port, and accordingly the area and shape of the gas port may be made the optimum, however small or whatever shape that may be, because it is no longer necessary to enlarge it beyond the optimum in order to accommodate a suflicient volume of waste gas.

In order that the invention may be clearly understood and readily carried into effect two constructions in accordance therewith will now be described by way of example with reference to the accompanying drawings, in which Figure 1 is a central longitudinal section through part of the port structure at one side of a furnace;

Figures 2 and 3 are sections respectively on the lines II-II and III--III of Figure 1;

Figure 4 shows the valve member on an enlarged scale;

Figure 5 is a section on the line VV of Figure 4; and

Figures 6 and '7 are sections corresponding to Figures 1 and 2 through a furnace with a modified form of valve.

Referring first to Figures 1 to 5, the furnace has the usualhearth and regenerating chambers but these are not shown. The port structure passages respectively,

shown consists of brickwork in which there is formed a gas inlet passage I leading from the gas regenerating chamber and communicating with a further passage 2 the end of which constitutes the gas port 3. Two air inlet passages 4 and lead from the air regenerator chamber to a passage or space '6 in which the air that rises up them unites, flowing through this passage, the end of which constitutes the air port 1 which is arranged to deliver air around the gas delivered by the gas port 3. The ports and passages so far described are all of standard construction.

According to the invention a connection 8 is formed in the brickwork at the top of the furnace between the space or passage 6 and the gas passage I. This connection is controlled by a water-cooled damper 9 which slides in a watercooled chase II] which extends through the brickwork across the connection 8 and also across the gas passage 2. The damper 9 is ported, being formed with an opening I l. Figures 4 and 5 show the construction of the damper in detail and in particular the way in which water-cooling tubes [2 are arranged within it.

A single-acting hydraulic motor i3 is connected through a rope l4 passing over pulleys 5 to the top of the damper 9 and when this motor is operated it raises the damper against the influence of gravity.

When gas and air are entering at the side of the furnace illustrated the damper is raised and closes the connection 8 and opens the gas passage 2. When the gas is leaving the furnace at the side illustrated the damper is lowered into the position shown in Figure l, and it will be seen that the opening ll then registers with the connection 8 and that the gas passage is closed so that no gas flows through the port 3. All the gas leaving the furnace passes through the air port I and it divides at the point where the

air passages

4 and 5 meet, some passing through each of these passages and some through the connection 8 and down the gas passage I. It will be understood that the amounts of the waste gas that pass through the air and gas regenerator chambers respectively may be varied in any appropriate way, such as by varying the suction applied.

The two operating motors l3 of the furnace are preferably synchronized with the main gas reversing valve so that the valve members are automatically moved whenever the furnace is reversed.

In the modified construction shown in Figures 6 and 7 the only difference is that the sliding damper is replaced by a pivoted damper it carried by a spindle I! through which water is introduced to cool the damper. A water-cooled frame it is provided to constitute an abutment for the damper l6 in its two operating positions.

A particular advantage of the construction according to the invention is that the gas port need not be water-cooled and that water-cooling can be confined to a part of the furnace which is readily accessible by the r moval of a minimum of brickwork.

I claim:-

1. In a reversible regenerative furnace, a port structure formed with gas and air inlet passages terminating in ports and, with a connection running between points in said gas and air inlet a single valve member which in one position opens said connection to place the gas and air inlet passages in communication with one another and simultaneously closes the gas port, and in the other position closes said connection to shut off the gas and air inlet passage from one another and simultaneously opens the gas port to place it in com munication with the gas inlet passage.

2. In a reversible regenerative furnace, a port structure formed with gas and air inlet passages terminating in ports in a fixed part of the structure and with a connection running between points in said gas and air inlet passages respectively, and a single valve member which in one position opens said connection to place the gas and air inlet passages in communication with one another and simultaneously closes the gas port, and in the other position closes said connection to shut off the gas and air inlet passage from one another and simultaneously opens the gas port to place it in communication with the gas inlet passage.

3. In a reversible regenerative furnace, a port structure at each side of the furnace, each of said port structures being formed with a gas inlet passage terminating in a gas port and with two inlet passages meeting together and terminating in an air port arranged to deliver air adjacent gas leaving the gas port and also with a connection running from the point where said air inlet passages meet, and a single valve member which in one position opens said connection to place the gas and air inlet passages in communication with one another and simultaneously closes the gas port, and in the other position closes said connection to shut off the gas and air inlet passage from one another and simultaneously opens the gas port to place it in communication with the gas inlet passage.

4. In a reversible regenerative furnace, a port structure formed with gas and air inlet passages terminating in ports and with a connection running between points in said gas and air inlet passages respectively, and a single valve member in the form of a ported slide valve which in one position opens said connection to place the gas and air inlet passages in communication with one another and simultaneously closes the gas port, and in the other position closes said connection to shut off the gas and air inlet passage from one another and simultaneously opens the gas port to place it in communication with the gas inlet passage.

5. In a reversible regenerative furnace, a port structure formed with gas and air inlet passages terminating in ports in a fixed part of the structure and with a connection running between points in said gas and air inlet passages respectively, and a single valve member in the form of a ported slide valve which in one position opens said connection to place the gas and air inlet passages in communication with one another and simultaneously closes the gas port, and in the other position closes said connection to shut oiT the gas and air inlet passage from one another and simultaneously opens the gas port to place it in communication with the gas inlet passage.

6. In a reversible regenerative furnace, a port structure at each side of the furnace, each of said port structures being formed with a gas inlet passage terminating in a gas port and with two air inlet passages meeting together and terminating in an air port arranged to deliver air adjacent gas leaving the gas port and also with a connection running from the point where said air inlet passages meet, and a single valve member in the form of a ported slide valve which in one position opens said connection to place the gas and air inlet passages in communication with one another and simultaneously closes the gas port, and in the other position closes said connection to shut off the gas and air inlet passage from one another and simultaneously opens the gas port to place it in communication with the gas inlet passage.

7. In a reversible regenerative furnace, a port structure formed with gas and air inlet passages terminating in ports and with a connection running between points in said gas and air inlet passages respectively, and a single valve member in the form of a pivoted damper which in one position opens said connection to place the gas and air inlet passages in communication with one another and in another position closes said connection to shut off the gas and air inlet passage from one another and simultaneously opens connection to place the gas and air inlet passages in communication with one another and simultaneously closes the gas port, and in the other position closes said connection to shut oil the gas and air inlet passage from one another and simultaneously opens the gas port to place it in communication with the gas inlet passage.

9. In a reversible regenerative furnace, a port structure at each side of the furnace, each of said port structures being formed with a gas inlet passage terminating in a gas port and with two air inlet passages meeting together and terminating in an air port arranged to deliver air adjacent gas leaving the gas port and also with a connection running from the point where said air inlet passages meet, and a single valve member in the form of a pivoted damper which in one position opens said connection to place the gas and air inlet passages in communication with one another and simultaneously closes the gas port, and in the other position closes said connection to shut oil? the gas and air inlet passage from one another and simultaneously opens the gas port to place it in communication with the gas inlet passage.

JOSEPH BLAKE ROW'LEY BROOKE.