US3566908A

US3566908A - Gastight, liquid sealed, swing-type valve assembly

Info

Publication number: US3566908A
Authority: US
Inventors: Edward M Macnak
Original assignee: National Dust Collector Corp
Current assignee: National Dust Collector Corp; US Filter Systems Inc
Priority date: 1969-06-16
Filing date: 1969-06-16
Publication date: 1971-03-02
Anticipated expiration: 1988-03-02
Also published as: JPS4828173B1; GB1306262A; DE2027860A1

Abstract

A gastight, liquid sealed, swing-type valve construction for controlling the flow of gases through a conduit comprising a housing having sidewalls and open at the upper and lower ends for connection with the conduit, a swing valve mounted for pivotal movement about a horizontal axis adjacent one end of the housing between a conduit closing shutoff position and an open position substantially out of the flow path of gas through said housing. Annular trough means is provided on the upper side of the swing valve so that when the valve is in said closed position said trough means may hold a body of sealing liquid around the perimeter of the valve and thereby establish a gastight liquid seal around the interior of the housing wall. Annular curtain wall means around the inside of the housing wall extends inwardly and downwardly of the sidewalls into the liquid in the trough means forming said liquid seal when the swing valve is in said closed position.

Description

United States Patent [72] Inventor Edward M. Macnak [54] GASTIGHT, LIQUID SEALED, SWING-TYPE 1,616,561 2/1927 VanAckeren ABSTRACT: A gastight, liquid sealed, swing-type valve construction for controlling the flow of gases through a conduit comprising a housing having sidewalls and open at the upper VALVE ASSEMBLY and lower endsfor connection with the conduit, a swing valve mounted for pivotal movementabout a horizontal axis ad- 6 Claims, 3 Drawing Figs.

acent one end of the housing between a conduit closing shu- [52] US. Cl 137/248, t ff i i and an open position substantiany out f the fl w l37/609 path of gas through said housing. Annular trough means is [5 1 1 Int. provided on the upper side of the swing valve so that when the of valve is in said closed position aid trough means may a body of sealing liquid around the perimeter of the valve and [56] References cued thereby establish a gastight liquid seal around the interior of UNITED STATES PATENTS the housing wall. Annular curtain wall means around the in- 607,035 7/ 1898 Hannan 137/248 side of the housing wall extends inwardly and downwardly of 1,001,399 8/191 1 Herrick 137/248 the sidewalls into the liquid in the trough means forming said 1,597,541 8/ 1926 Plantinga l37/248X liquidiseal when the swing valve is in said closed position.

44 as 40 38 v I l I I i 42 1 46 I l ,4 32 32- -x ,f1

82 34 I ,s ao\ 34 60 I 54 ss 56 l 4, 1 72 l 72 r l I li I II. i] 12 I J '6 I t l8 I 18 20 I0 I:

PATENTED MAR 2 I97! SHEET 1 OF 2 FIG. I

INVENTORI EDWARDHMACNAK ATT'YS PATENTEDHAR 21971 SHEET 2 OF 2 m w E N OE mm GATiGliiTi', LHQUID SEALED, SWWG-TYPE VALVE ASSEMBLY The present invention is directed towards a new and improved gastight, liquid sealed, swing-type valve construction for controlling the flow of gases, such as heated stack gases, through a conduit. The swing-type valve construction of the present invention is especially adapted for use in providing gastight valving in large size duct work commonly used for connecting a pair of cupola furnaces to a single gas scrubbing unit. In such installations one of the furnaces is usually in operation while the other furnace is shut down for repair, and the duct work and valving provide a means whereby the stack gas from the operative furnace can be directed into the gas scrubber without back flow into the inoperativefurnace. The gases generated in the operative furnace are of extremely high temperature and it is desirable that a positive, gastight seal be maintained between the operative and inoperative furnace stacks so that workmen in and around the inoperative furnace will not run the risk of being burned or overcome by the leakage of hot gases from the operative furnace.

It is therefore an object of the present invention to provide a new and improved gastight, liquid sealed, swing-type valve construction.

Another object of the present invention is to provide a new and improved liquid sealed, swing-type valve construction for controlling the flow of gases through a conduit and especially adapted for use in conjunction with the exhaust conduit system between a pair of furnaces or other gas generating devices wherein one of the furnaces is in operation during a period while the other is shut down orinoperative.

Still another object of the present invention is to provide a new and improved swing-type valve assembly of the character described which provides a gastight seal when closed yet is simple in construction, easy to operate, and relatively low in cost.

Yet another object of the present invention is to provide a new and improved liquid sealed, swing-type valve construction having a valve member which is movable between two operative positions for alternately sealing off one of a pair of input ducts from a common outlet duct.

The foregoing and other objects and advantages of the present invention are provided in one illustrated embodiment thereof comprising a gastight, liquid sealed, swing-type valve asembly for controlling the flow of gases through a conduit, said assembly including housing means having sidewalls and open at the upper and lower ends for connection with said conduit system. A swing-type valve member is mounted for pivotal movement about a horizontal pivot axis adjacent one end of the housing for movement between a substantially horizontal closed position and an open position wherein the valve is out of the flow path of gases passing through the housing. Annular trough means is provided on the upper side of the valve member for holding a supply of liquid (usually water) to form a peripheral seal between the outer periphery of the valve (when closed) and the walls of the housing. An annular curtain wall structure is provided to extend downwardly into the liquid trough in direct contact with the liquid therein, thereby establishing a gastight liquid seal between the closed valve member and housing walls.

For a better understanding of the present invention, reference should be had to the following detailed description taken in conjunction with the drawings, in which:

FIG. 1 is a side elevational view of a typical cupola furnace installation wherein a pair of furnaces are provided adjacent a single gas scrubber, and a pair of liquid sealed, swing-type valve assemblies, constructed in accordance with the present invention, are provided for controlling the flow of gases between the furnaces and the gas scrubber.

FIG. 2 is an enlarged, elevational, sectional view of a gastight, liquid sealed, swing-type valve assembly constructed in accordance with the present invention; and

FIG. 3 is an elevational sectional view of another embodiment of a gastight, liquid sealed, swing-type valve assembly constructed in accordance with the features of the present invention.

Referring now, more particularly, to the drawings, in FIG. ll therein is illustrated a typical cupola furnace installation it) wherein a pair of cupola furnaces i2 and 14 are positioned in adjacent side-by-side relation in close proximity to a single gas scrubber 66. Each of the furnaces includes a base section 16 wherein the refined molten metal is collected in a pool, which pool of metal is eventually tapped, permitting the molten metal to flow out through a trough or spout 18 into a suitable carrier or ladle 20 mounted for movement along a track 22. The furnaces each include an elongated upright stack 24 in which charges of iron ore, limestone, and coke are placed and the metal is refined in the heat and collects in the base 16. A charging opening 28 is provided in each stack above a charging floor or structure 26 to facilitate introduction of the charges of limestone ore and coke into the stacks.

At the upper end of each stack, a quenching chamber 30 is provided and, preferably, the chamber is of the type described and claimed in US. Pat. No. 3,432,153, which patent is assigned to the same assignee as the present invention. Each quenching chamber 30includes an internal, conically shaped baffle 32 with a cylindrical annular skirt 34 depending downwardly from the lower edge thereof. The baffle is arranged in coaxial alignment with the vertical axis of the stack and is spaced above the upper end of the stack. Water is introduced into the quenching chambers from a supply line 36 and a pair of branch lines 38, each branch having an individual control valve 40 thereinQQuenching water is delivered onto the conical baffles 32 through nozzles 42, and the water flows downwardly over the baffles and around the skirts 34 providing a substantially cylindrical curtain of flowing water between the lower end of the skirt and the upper end of the stack. The hot gases generated in the furnace stack pass outwardly through the flowing curtain of waterand are quenched or cooled by the water and, in addition, much of the contaminant material in the gas is collected in the water. The quenched gas may be discharged directly out of the upper end of the quenching chamber 30 through the outlet stacks 44, but, preferably, instead of discharging the quenched gas into the atmosphere, at this point the quenched gas is diverted into a downturn elbow 46 in communication with the sidewall of the quenching chamber by closing an upper valve member 4%. The valve members 48 are supportedoncables 50 for movement between lower or open positions, as shown in the lefthand quenching chamber of HG. l, and an upper or closed position, as shown on the right-hand quenching chamber. Movement of the cable to raise or lower the valve members 43 is controlled by suitable means, such as power operated winches 52. When one of the furnaces is shut down or out of operation, the valve member 48 in the quenching chamber on the upper end of the furnace stack is usually lowered to the open position in order to permit a free flow of air to move through the furnace stack and cool the unit down after a heat. The valve member 48 in the operating furnace may be closed or opened, depending upon whether or not the gas scrubber on is used, as will be described hereinafter.

The flowing water curtain formed by the baffle member 32 and skirt 34 in each quenching chamber 30 is effective to remove and collect some of the contaminant material in the gas, and the contaminated water is collected in an annular trough 54 around the bottom of each quenching chamber adjacent the top end of the associated furnace stack. Each liquid collecting trough 54 is formed with a sloping bottom wall and a drain conduit 56 is connected at the lowest point in the bottom of the trough. A float operated control valve 5% is provided in each drain conduit 56 in order to maintain a minimum level of liquid in the collecting trough for sealing with the skirt 34 when the baffle is lowered to close off the stack. The upper level of the liquid in each trough is controlled by'an overflow line 60 and the

lines

56 and 60 are connected to a common drainline 62, and a line 64 which carries the collected water to a sludge treatment facility or a sewer (not shown).

As described in the aforementioned United States patent, when one of the

cupola furnaces

12 or 14 is shut down and out of operation, the lining of the stack usually requires repair and maintenance on the inside surface and, after the stack has cooled sufficiently, workmen normally enter the stack through the charging opening 28 to perform the needed repairs. During this period, the valve member 48 at the upper end of the quenching chamber on the inoperative furnace is maintained open to provide a good draft and air ventilation through the stack.

in addition to the contaminant collecting quenching action which takes place within an operating quenching chamber 30, as the stack gas passes through the flowing water curtain, further purification of the gas may be required to meet air pollution standards. A single gas scrubber 66 is used in conjunction with each pair of cupolas for-removing additional contaminants still contained in the gas after quenching in the chamber 30. When the upper valve 48 is closed, the quenched gas flows out of the quenching chamber through the elbow 46 and downwardly into one side of a downtake duct system, generally indicated as 68. The lower end of the downtake system includes an elbow 70 for delivering the quenched hot gasses from the operating furnace into the gas scrubber 66, which is preferably of the wet-scrubbing type; for example, as

shown in US. Pat. No. 3,348,825. Because only one of the furnaces is normally operated at any given period, only one gas scrubber 66 is designed to interconnect the quenching chamber of one or the other operative cupola furnaces l2 and 14 with the gas scrubber. As shown in FIG. 1, the furnace 14 is in operation and the furnace 12 is shut down for repairs, and in this situation it is normally essential that none of the hot gases generated in the operative furnace leak or flow back into the stack of the inoperative furnace in which workmen might be present. The gases generated by cupola furnaces normally contain large quantities of carbon monoxide and other gases harmful to the human and, accordingly, means must be provided in the downtake duct system 68 for establishing a gastight seal between one side of the system connected to the operative furnace and the opposite side of the system to thereby ensure safety for workmen in and around the stack of the inoperative furnace while making repairs therein.

The downtake duct system includes a Y duct 72 connected to the upper end of the lower input elbow 70 connected to the scrubber and each opposite, angularly upwardly extending leg 72a and 72b of the Y duct is connected to a transition section 74 and an elbow 76. The upper end of each elbow 76 in turn is connected to the lower end of a gastight, liquid sealed, swingtype valve assembly 80 constructed in accordance with the present invention and designed to provide a gastight seal between the operative and inoperative furnaces. The upper end of each valve assembly 80 is in communication with a downtake elbow 46 through another transition section 82, and thus either or both of the quenching chambers 30 on the respective furnaces can be connected to the scrubber 66 through the downtake duct system.

when the right-hand furnace 14 is in operation and the upper valve member 48 on the associated quenching chamber 30 is closed, the hot gases generated in the furnace flow outwardly from the furnace stack through the moving water curtain in the quenching chamber. The quenched gas flows out of the quenching chamber and downwardly into the right-hand side of the duct system 68 via the right-hand elbow 46 and transition 82 and the open right-hand swing gate valve assembly 89. The right-hand swing gate valve assembly 80 is illustrated in the open position, and the left-hand valve assembly is in a closed or gastight, sealed position, so that the gases do not back-flow upwardly through the left-hand leg 72a of the Y duct '72 and into the furnace 12. Because the gases generated in the furnaces may be extremely hazardous to health, it is essential that gases from the operating cupola furnace are effectively sealed against entry into the stack of the inoperative furnace wherein workmen might be present.

in accordance with the present invention, each liquid sealed, swing-type valve assembly is adapted to open or seal off the flow of gas through the duct system or conduits leading to and from the valve housing between the respective quenching chambers 30 and the gas scrubber 66. Referring now specifically to FIG. 2, the swing-type valve assembly 80 includes a generally rectangular housing 84 having one pair of parallel opposite sidewalls 86 and a second pair of

sidewalls

88 and 90 normal thereto, and the sidewalls thus provide for a generally rectangular flow cross section in the housing. The sidewall 0 is formed with an enlarged, rectangular opening 90a therein in communication with a boxlike, generally rectangular, lateral extension or subhousing 92 for accommodating a movable swing-type valve member when the valve is in a vertical, open position. The subchamber 92 includes a horizontal bottom wall 94, a lower vertical sidewall portion 96, an upper vertical sidewall 98 comprising a channel member, and a horizontal top wall 102 having an outer edge portion joined to the upper flange of the channel. The lower flange of the channel is connected to an angle 104 along the upper edge of the vertical wall 96. End walls of the subhousing 92 are formed by rectangular, outwardly extending projections 86a integral with the main housing sidewalls 86. The channel 98 is readily removable from the position shown to permit access to the interior of the subhousing 92 and, for this purpose, the channel member includes flanges 980 at opposite ends which are fastened to the housing sidewalls with a plurality of bolts 106.

At the upper end portions of the subchamber 92, the sidewall extensions 86a are covered with rectangular stiffening plates 87 and a pair of flange bearings 124 are mounted on the plates to support and journal opposite end portions of a horizontal pivot axle 122. A rectangular, swing-type valve member 120 (shown in the horizontal closed or sealed position in solid lines in FIG. 2) is supported for pivotal movement by the axle 122, and the valve member is movable between the closed horizontal position and an open vertical position (dotted lines) wherein the valve member occupies the space enclosed by the subchamber 92, in which position the valve member is laterally offset from the normal flow path of the gases moving vertically through the housing 84 between the upper and lower opposite ends.

in order to turn the axle 122 to move the valve member 120 between the open and closed positions, there may be provided a fluid cylinder 108 having its lower end pivotally connected to a support bracket 110 mounted on a platform extension 112 projecting horizontally outwardly from the sidewall 90 of the housing at the lower end thereof. The upper or rod end of the fluid cylinder 108 is pivotally connected to a lever arm 114; which is connected to the outer end of the axle 122. When fluid is introduced into the upper end of the cylinder, causing the rod to be retracted into the cylinder body, the valve member is pivoted in a clockwise direction to the closed or sealing position, as shown in solid lines, and when pressurized fluid is introduced into the opposite lower end of the cylinder, the rod is extended outwardly of the cylinder body (as shown by dotted lines), causing the valve member to pivot in a counterclockwise direction to the downwardly extended vertical or open position.

In accordance with the present invention, the valve member 120 is adapted to effect a gastight seal against the flow of gas through the housing 84 between opposite ends when the valve member is in the horizontal or closed position. The valve member comprises a pair of parallel, spaced apart, outer side members 126 which are fixedly connected at their inner ends to the supporting axle 122, and these side members are joined by cross members 128 normal thereto and parallel with the supporting axle 122. The

members

126 and 128 are preferably constructed of angle iron and form a generally rectangular shaped outer framework for the valve. A rectangular center panel 130 is joined to the inside edges of the

angles

126 and 128 of the frame by pairs of

vertical strips

132 and 134, and the

vertical strips

134 and 132 and the outer frame angles 126 and 128 cooperate in pairs to form a continuous U-shaped, upwardly facing trough 136 extending around the outer periphery of the gate for containing liquid to provide gastight sealing when the valve is closed. A downwardly depending skirt structure (generally indicated as 140) is attached to the inside surfaces of the

housing walls

86, 88, and 90 and forms a continuous sealing structure around the inside of the housing to cooperate with the liquid in the trough 136. The skirt structure includes a plurality of skirt members 142 sloping inwardly and downwardly of the respective walls of the housing 84, and a plurality of vertically disposed skirt members 144 are joined to the lower edges of the sloped members 142. The lower edge portion of the vertical skirt members 144 extends downwardly into the liquid contained in the trough 136 around the periphery of the valve member 120 to establish a gastight liquid seal when the valve member is closed. The sealing liquid (preferably water) is introduced into the housing 84 and trough 136 through a conduit 146 and supply line 148 (shown in schematic form). The conduit 146 enters the housing at a position above the sloping skirt members 142, so that sealing liquid is directed downwardly and inwardly by the skirt structure to collect in the trough 136 when the valve is in a closed position. The flow rate of sealing liquid supplied to keep the trough 136 in a filled condition is dependent upon the rate of evaporation of the water, and if extremely hot gases are present in the system the evaporation may be high enough to require a continuous supply of water to the trough. Once the trough is full, any excess liquid spills over the vertical flanges of the outer frame angles 126 and 128, and this excess liquid generally passes downwardly through the valve housing 84 and is taken into the gas scrubber 66.

When the swing valve 120 is pivoted-from the sealing or closed, horizontal position to the vertical open position (shown in dotted lines), the valve member then occupies a position in the subchamber 92 and is laterally offset from the mainstream flow of gases in a vertical direction through the housing 84. The valve assembly 80 thus provides a gastight swing valve suitable for use in large ducts and conduits. The valve assembly is simple in construction, easy to operate and maintain, and positively prevents gas leakage which might otherwise endanger workmen in or around the stack of an adjacent shutdown cupola furnace.

Referring now to FIG. 3, therein is illustrated a modified embodiment of a gastight, liquid sealed, swing-type valve assembly which employs a dual acting, pivoting valve member 220, which is swingable from a first horizontal position (solid lines) closing off the gas flow from a left-hand transition duct 82 to a second horizontal position (dotted lines), closing off gas flow from the right-hand ducts 82. When the modified dual acting swing valve assembly 180 is utilized in connection with a typical furnace installation, as shown in FIG. 1, the valve housing 184 itself accomplishes the same purpose as the Y duct 72 in the downtake duct assembly 68, as shown in FIG. I, and the lower end of the valve housing 184 may be connected to the scrubber intake elbow 70 via a transition section 172.

The housing 184 of the modified double acting swing valve assembly 180 is formed by pairs of parallel

opposite sidewalls

186 and 188, respectively, and the swing valve 220 is supported on an axle 222 extending transversely through the housing between opposite sidewalls 186 adjacent the upper end thereof at the center of the housing.

The modified swing valve 220 includes a rectangular central enclosure or boxlike structure formed with spaced apart rectangular panels 230 connected around their outer periphery with

strip members

232 and 234. The strip members form the inside wall of a pair of backto-back, opposite face, peripheral

liquid troughs

236 and 336, which are formed by rectangular trough structures comprising back-to-

back angle members

226 and 228. When the swing valve 220 is in the lefthand position, as shown in FIG. 3, the liquid trough 236 faces upwardly and cooperates with a skirt structure 240 around the left-hand upper opening of the housing. Liquid for sealing the swing gate in this position is supplied from the conduit outlet 246 and supply line 248.

The inside angles 228 of the valve trough frame are connected to the pivot axle 222 by a plurality of bracket arms 235 so that the swing valve can freely pivot from the left-hand horizontal position to the opposite side of the housing (dotted lines) wherein the right-hand upper opening is sealed off. In the right-hand horizontal position, the trough 336 faces upwardly to cooperate with the skirt 240 around the upper righthand opening of the housing.

It will thus be seen that the swing valve assembly employs a single dual acting swing gate 220 which is capable of providing a gastight seal with a selected upper opening in the valve housing.

Iclaim:

l. A gastight liquid sealed valve assembly for controlling the flow of gas through a conduit comprising a housing means having pairs of vertical sidewalls and adapted to be connected at opposite ends to said conduit, a swing valve mounted for pivotal movement about a horizontal axis adjacent the one end of said housing between a conduit blocking horizontal position and-an open position, peripheral trough means on one side of said swing valve facing upwardly when said gate is closed for holding a body of liquid to establish a liquid seal between the perimeter of said swing valve and the walls of said housing, and curtain wall means extending inwardly and downwardly of the sidewalls of said housing and having a peripheral lower edge portion adapted to extend downwardly into the body of liquid in said trough means to effect a gastight seal when the swing valve is closed, said housing including lateral chamber means in communication with one sidewall for enclosing said swing valve in vertical open position depending downwardly of said pivot axis, said chamber being offset horizontally from the mainstream of vertical gas flow between opposite ends of said housing.

2. The valve assembly of claim 1 wherein said annular curtain wall means includes an upper segment sloping inwardly and downwardly of the sidewalls of said housing and wherein said lower edge portion comprises a continuous vertical skirt spaced inwardly from the outer periphery of said trough means on said swing valve.

3. The valve assembly of claim 2 including liquid dispensing means above the sloping segment of said curtain wall for dispensing liquid into said housing for filling said trough means.

4. A gastight valve assembly for controlling the flow of gas between a pair of upper branch conduits and a common lower branch conduit, said assembly comprising a valve housing having sidewalls, a pair of spaced apart openings at the upper end in communication with said upper branch conduits and an opening at the lower end in communication with said lower branch conduit, swing valve means mounted for pivotal movement about a horizontal axis spaced between said upper openings and swingable between a first horizontal position on one side of said axis for closing off the gas flow from one upper branch conduit and a second horizontal position on the other side of said axis for closing off the gas flow from the other upper branch conduit, said swing valve comprising a pair of peripheral liquid trough means in back-to-back array on opposite sides thereof for holding liquid to establish a liquid seal around the perimeter of said swing valve and a selected one of said upper openings, and a pair of curtain wall means depending downwardly and inwardly from around each of said. upper openings, each wall means including a a lower peripheral skirt portion adapted to extend into the liquid in one of the trough means on said valve when closed.

5. The gastight valve assembly of claim 4 wherein said swing valve means is pivotal in a downward direction from either of said first or second horizontal positions when moved from one position to the other and wherein a liquid seal is established between said pivot axis and a selected upper opening when said swing valve means is in position closing said opening.

6. The valve assembly of claim 4 including liquid dispensing means above each of said curtain wall means for filling one of said trough means on said swing valve.

Claims

1. A gastight liquid sealed valve assembly for controlling the flow of gas through a conduit comprising a housing means having pairs of vertical sidewalls and adapted to be connected at opposite ends to said conduit, a swing valve mounted for pivotal movement about a horizontal axis adjacent the one end of said housing between a conduit blocking horizontal position and an open position, peripheral trough means on one side of said swing valve facing upwardly when said gate is closEd for holding a body of liquid to establish a liquid seal between the perimeter of said swing valve and the walls of said housing, and curtain wall means extending inwardly and downwardly of the sidewalls of said housing and having a peripheral lower edge portion adapted to extend downwardly into the body of liquid in said trough means to effect a gastight seal when the swing valve is closed, said housing including lateral chamber means in communication with one sidewall for enclosing said swing valve in vertical open position depending downwardly of said pivot axis, said chamber being offset horizontally from the mainstream of vertical gas flow between opposite ends of said housing.

4. A gastight valve assembly for controlling the flow of gas between a pair of upper branch conduits and a common lower branch conduit, said assembly comprising a valve housing having sidewalls, a pair of spaced apart openings at the upper end in communication with said upper branch conduits and an opening at the lower end in communication with said lower branch conduit, swing valve means mounted for pivotal movement about a horizontal axis spaced between said upper openings and swingable between a first horizontal position on one side of said axis for closing off the gas flow from one upper branch conduit and a second horizontal position on the other side of said axis for closing off the gas flow from the other upper branch conduit, said swing valve comprising a pair of peripheral liquid trough means in back-to-back array on opposite sides thereof for holding liquid to establish a liquid seal around the perimeter of said swing valve and a selected one of said upper openings, and a pair of curtain wall means depending downwardly and inwardly from around each of said upper openings, each wall means including a a lower peripheral skirt portion adapted to extend into the liquid in one of the trough means on said valve when closed.