DAMPER SYSTEM

BACKGROUND
Field

Embodiments of the present disclosure generally relate to dampers to control fluid flow.

Description of the Related Art

FIG. 1A illustrates a schematic view of a stack assembly 1 for the combustion of one or more gases. The stack assembly 1 includes a combustion chamber 2 and a stack 3. The combustion chamber 2 includes a burner 4 configured to combust one or more combustible gases supplied by a combustible gas supply line 5. An air supply line 6 supplies air to the combustion chamber 2 to facilitate the combustion. The flue gases from the combustion are vented to the atmosphere through the stack 3. A conventional damper 100 is connected to the stack 3 to control the flow of gases through the stack 3.

FIG. 1B-1C illustrates the conventional damper 100. The conventional damper 100 includes a conduit body 110, a choke ring 120, a first blade 131, a second blade 132, a first shaft 141, a second shaft 142, a first actuator 151, and a second actuator 152.

FIG. 1B is a top view of the conventional damper 100 with the blades 131, 132 in a closed position. The conduit body 110 defines a body opening 111. The choke ring 120 and blades 131, 132 are disposed within the body opening 111. The choke ring 120 is attached to the conduit body 110 and extends radially into the body opening 111 from the inner surface of the conduit body 110. The choke ring 120 has thickness (extending in along the Z-axis) that is about the same thickness as the first and second blades 131, 132. The gas flows through the stack 3 at low velocities, such as velocities less than 15 ft/s. The choke ring 120 includes a choke opening 121 which has a smaller flow area than the body opening 111, causing the choke ring 120 to restrict gas flow. The choke ring 120 causes an increase in velocity as the gases flowing through the choke opening 121 while also causing a pressure drop to aid in the control of the low velocity fluid flow with the blades 131, 132 as compared to a more traditional damper which does not have a choke ring 120.

The first and second shafts 141, 142 are shown in dashed lines because both shafts are located under a corresponding blade 131, 132. Each blade 131, 132 may be secured to the corresponding shaft by an attachment member, which may be a bolt that extends through a flange attached to the underside of the respective blade 131, 132. The first actuator 151 rotates the first shaft 141 to rotate the first blade 131 and the second actuator 152 rotates the second shaft 142 to rotate the second blade 132. Having separate actuators for each blade 131, 132 increases the complexity of the conventional damper 100 and maintenance associated therewith.

The first and second blades 131, 132 are disposed within the choke opening 121 and are rotatable to one or more positions between the closed position as shown in FIG. 1B and an open position shown by the dashed lines in FIG. 1C. Flow through the choke opening 121 is blocked or substantially blocked when the blades 131, 132 are in the closed position and flow increases as the blades 131, 132 are rotated toward the open position. Maximum flow through the opening 121 is allowed when the blades 131, 132 are in the open position. The blades 131, 132 are rotated to positions between 0 degrees (closed) and 90 degrees (fully open) to change the flow of the flue gases through the conventional damper 100.

FIG. 1C is a cross-sectional view of the conventional damper 100 in FIG. 1B. FIG. 1C illustrates the first and second blades 131, 132 rotated about 45 degrees and also shows the first and second blades 131, 132 in dashed lines rotated 90 degrees in the fully open position. When in the closed position, the first tip 136 of each blade 131, 132 is horizontally adjacent to and faces the choke ring 120. The first tip 136 moves away from the choke ring 120 as the blades 131, 132 rotate away from the closed position such that the first tip 136 is no longer horizontally adjacent to the choke ring 120. Therefore, the distance—and thus area of the gap-between first tip 136 and the choke ring 120 increases as each blade 131, 132 rotates away from the closed position. This gap is shown as G1 for the first blade 131 rotated about 45 degrees open and G2 for the first blade 131 rotated about 90 degrees. Fluid flows around the first tip 136 through the growing gap between the choke ring 120 and the first tip 136 as the blades 131, 132 open. Likewise, the distance and area between the opposing second tips 137 increases as the angle of rotation increases. Every degree that the blades 131, 132 opens has diminishing returns on the controllability of the flue gases due to the ever increasing area of the gap between the first tip 136 and the choke ring 120. Additionally, the an area of a gap between the opposing second tips 137 increases as the first and second blades 131, 132 are rotated open which also affects the ability of the conventional damper 100 to control the flow of fluid.

FIG. 1D illustrates a performance curve of the conventional damper 100, shown as curve C1. The ability of a damper to cause a pressure drop is indicative of the damper's ability to control fluid flow. The performance curve shows the pressure drop caused by the conventional damper 100 over a percentage of openness of the blades. The Y-axis shows the pressure drop in inches of water and the X-axis represents the percentage of openness of the damper assembly. The first and second blades 131, 132 are both halfway open at 50% open along the X-axis. Both the first and second blades 131, 132 are in the open position when at 100% open along the X-axis.

As shown in FIG. 1D, the pressure drop along the first performance curve C1 is not linear. The pressure drop caused by the conventional damper 100 decreases as the conventional damper 100 is opened. The steep slope between about 40% to about 56% open illustrates that the quick decay in the ability of the conventional damper 100 to cause a pressure drop per degree of openness. Eventually, the slope of the performance curve C1 begins to flatten out, which shows that the ability of conventional damper 100 to cause a pressure drop decreases to the point that further opening the blades does not cause an appreciable effect on the fluid flowing through the conventional damper 100. For example, the pressure drop caused when the blades are fully open (100% open) is similar to the pressure drop when the blades are between 70% and about 90% open. As a result, it is difficult to control the flow of flue gases through the stack 3 and/or pressure within the combustion chamber 2 to promote efficient combustion by the burner 4, resulting in the production of unwanted byproduct gases. A traditional damper, which does not include a choke ring 120 to cause a pressure drop, has an even worse performance curve; especially at lower flow velocities.

There is a need in the art for a damper that minimizes the gap available for fluid to flow around the tip of the blades to increase the pressure drop per unit of rotation of the blades to improve fluid flow control. Additionally, there is a need in the art for a single actuator assembly to rotate the damper blades.

SUMMARY

In one embodiment, a damper system including a conduit body, a wall assembly, and a first blade. The conduit body includes an opening. The wall assembly includes a first wall and a second wall disposed in the conduit body extending across the opening. The first blade is disposed within the conduit body between the first wall and the second wall.

In one embodiment, a damper system includes a conduit body, a ring, a first blade, a second blade, and an actuator assembly. The conduit body including an opening. The ring is disposed in the conduit body. The ring includes a first vertical wall and a second vertical wall, wherein the first vertical wall and the second vertical wall at least partially span across the opening. The first blade disposed within an interior of the ring. The second blade is disposed in the conduit body exterior of the ring. The actuator assembly is configured to rotate the first blade prior to rotating the second blade.

In one embodiment, a method of operating a damper, includes rotating a first blade disposed in a conduit and between a first and second vertical wall from a closed position where a first tip of the first blade faces a first point of the first vertical wall to a first position where the first tip is adjacent a second point of the first vertical wall. A distance between the first tip and the second point is less than a distance between the first tip and the first point when the first blade is in the first position.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, may admit to other equally effective embodiments.

FIG. 1A illustrates a schematic of a stack assembly that includes a conventional damper system.

FIG. 1B illustrates a top view of the conventional damper system of FIG. 1A.

FIG. 1C illustrates a cross-sectional view of the conventional damper system of FIG. 1B.

FIG. 1D illustrates a performance curve of the conventional damper system of FIG. 1B.

FIG. 2A is a perspective view of a damper system including a wall assembly with at least two walls, according to embodiments described herein.

FIG. 2B is a cross-sectional view of the damper system of FIG. 2A, according to embodiments described herein.

FIG. 2C is a partial cross-sectional view of the damper system within the region of FIG. 2B that shows the gap reduction of the wall assembly, according to embodiments described herein.

FIG. 2D is a partial cross-sectional view of the damper system within the region of FIG. 2B that shows the gap reduction of the wall assembly, according to embodiments described herein.

FIG. 3 illustrates an exemplary performance curve of the damper system of FIG. 2A as compared to the conventional damper system of FIG. 1B.

FIG. 4A is a perspective view of the damper system showing both the inner blades and the outer blades in the closed position, according to embodiments described herein.

FIG. 4B is a perspective view of the damper system of FIG. 4A showing the inner blades in a halfway open position and the outer blades in the closed position, according to embodiments described herein.

FIG. 4C is a perspective view of the damper system of FIG. 4A showing the inner blades in an open position and the outer blades in the closed position, according to embodiments described herein.

FIG. 4D is a perspective view of the damper system of FIG. 4A showing the inner blades in an open position and the outer blades in the halfway open position, according to embodiments described herein.

FIG. 4E is a perspective view of the damper system of FIG. 4A showing the both the inner blades and outer blades in the open position, according to embodiments described herein.

FIG. 4F is a partial perspective view of the region circled in FIG. 4A, according to embodiments described herein.

FIG. 5 is a cross-sectional view of an exemplary damper system with a wall assembly including at least three walls, according to embodiments described herein.

FIG. 6 is a top view of an exemplary damper system, according to embodiments described herein.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

DETAILED DESCRIPTION

The present disclosure generally provides a damper for improved control over the flow of fluids.

FIG. 2A-2C illustrate an exemplary damper system 200 that includes a conduit body 210, a wall assembly 220, a first blade 231, a second blade 231, a third blade 233, a fourth blade 234, and an actuator assembly 250. The damper system 200 is connectable to one or more conduits, such as a flue gas stack.

FIG. 2A illustrates a perspective view of the damper system 200. The conduit body 210 defines a body opening 211. The conduit body 210 may include a coupling at each end configured to connect to one or more conduits. The coupling of the conduit body 210 may be a flange that can be attached to the conduit, such as being welded to a stack of a stack assembly. In other embodiments, the conduit body 210 and other components of the damper system 200 may be inserted into a conduit through a side opening in the conduit.

The wall assembly 220 is disposed in the body opening 211 to reduce the gap available for fluid to flow through as the blades 231-234 open and close which improves the performance of the damper system 200 as compared to conventional dampers. The wall assembly 220 is attached to the interior surface of the conduit body 210. In some embodiments, the wall assembly 220 may be welded directly to the conduit body 210 or attached to the conduit body 210 by a plurality of fasteners. The wall assembly 220 includes a first vertical wall 221 and a second vertical wall 222 that each extend (e.g., span) across the body opening 211. The first and second blades 231, 232 are disposed in the body opening 211 between the first wall 221 and the second wall 222. The third and fourth blades 233, 234 are disposed in the body opening 211 on opposing sides of the wall assembly 220. As shown, the third blade 233 is disposed between the inner surface of the conduit body 210 and the first wall 221 and the fourth blade 234 is disposed between the inner surface of the conduit body 210 and the second wall 222. In other words, the first and second blades 231, 232 are interior of the wall assembly 220 and the third and fourth blades 233, 234 are exterior of the wall assembly 220.

FIG. 2B is a cross-sectional view of the damper system 200 that illustrates the blades 231-234 in a closed position (e.g., 0 degrees of rotation). The dashed lines show the open position (e.g., 90 degrees of rotation) of each blade 231-234. In some embodiments, and as shown in FIG. 2B, the blades 231-234 are co-planar in the closed position. Each blade 231-234 has a first tip 236 and a second tip 237. The first and second tips 236, 237 may be flat as shown in FIG. 2B. In some embodiments, the first and second tips 236, 236 may be tapered, rounded, or curved. In the closed position, the first tip 236 of each blade 231-234 faces the wall assembly 220. The first and second vertical walls 221, 222 are parallel to one another and extend vertically along the Z-axis. The first and second vertical walls 221, 222 are shown having a height (H1) that exceeds the width (W1) of the first and second blades 231, 232 and the width (W2) of the third and fourth blades 233,234 when the blades 231-234 are in the closed position. As shown in FIG. 2B, the width is the dimension of the corresponding blade 231-234 from the first tip 236 to the second tip 237 when the blade is in the closed position. In other words, the height of the first and second vertical walls 221, 222 is shown as being greater than the height of the blades 231-234 when in the open position. As a result, the first tip 236 of each blade 231-234 is horizontally across from a portion of a respective vertical wall 221, 222 as each blade 231-234 rotates from the closed position to the open position in a clockwise or counterclockwise direction. As will be explained below, the presence of the vertical walls 221, 222 minimizes the area of the gap available for fluid to flow around the first tip 236.

The arrows labeled F in FIG. 2B illustrate an exemplary direction of fluid flow through the damper system 200. The fluid flows through the damper system 200 around the tips of the blades 231-234 as the blades 231-234 are rotated towards the open position. Flow through the damper system 200 is blocked or substantially blocked when the blades 231-234 are in the closed position and flow increases as the blades 231-234 are rotated toward the open position. Maximum flow through the damper system 200 is allowed when the blades 231-234 are each in the open position. The actuator assembly 250 is used to rotate the blades 231-234 to positions between 0 degrees (closed) and 90 degrees (open) to control the flow of fluid through the damper system 200. The blades 231-234 may be rotated in either the clockwise or counter-clockwise direction.

Each blade 231-234 is attached to a corresponding shaft 241-244. For example, each shaft 241-244 may be coupled to the bottom surface of a respective blade 231-234 by an attachment member, such as a as a bolt through flanges extending from the underside of the respective blades 231-234. Each shaft 241-244 may extend through ports 213 formed in the conduit body 210. Each shaft 241-244 may be coupled to one or more roller bearings (not shown) connected to the exterior of the conduit body 210 or within the ports 213 to facilitate the rotation of each shaft 241-244 relative to the conduit body 210.

The actuator assembly 250 is coupled to each shaft 241-244. The actuator assembly 250 is configured to rotate each shaft 241-244 over a range of degrees to rotate the corresponding blade 231-234 to one or more positions between the open and closed positions. In some embodiments, the actuator assembly 250 is configured to rotate the first and second blades 231, 232 (inner blades) prior to rotating the third and fourth blades 233, 234 (outer blades). For example, the first and second blades 231, 232 may be rotated to the open position before the third and fourth blades 233, 234 begin to rotate from the closed position. In some embodiments, the actuator assembly 250 is configured to rotate the first and second blades 231,232 together and the third and fourth blades 233, 234 together. The first and second blades 231,232 and the third and fourth blades 233,234 may be opened in a parallel or opposed fashion to one another. For example, to open the first and second blades 231,232 in a parallel fashion, the first blade 231 and second blade 232 are rotated in the same rotational direction. To open the first and second blades 231,232 in an opposed fashion, the actuator assembly 250 rotates the first blade 231 and the second blade 232 in opposite rotational directions. The third blade 233 may be opened in a parallel or opposed fashion with respect to the first blade 231, and the fourth blade 234 may be opened in a parallel or opposed fashion with respect to the second blade 232. The actuator assembly 250 shown in FIG. 2A, and the opening of the blades 231,234, will be discussed in greater detail in FIGS. 4A-4F.

FIGS. 2C-2D illustrates a partial cross-sectional view of the damper system 200 as shown by the circled region in FIG. 2B. FIGS. 2C-2D illustrates the opening of the first blade 231 relative to the first wall 221 to illustrate the gap reduction caused by the first wall 221. FIGS. 2C-2D are representative of the third blade 233 opening relative to the first vertical wall 221 and the second and fourth blades 232, 234 opening relative to the second vertical wall 222.

When the first blade 231 is in the closed position, the first tip 236 faces the first vertical wall 221. For illustrative purposes, the surface of the first tip 236 is flat and substantially parallel to the surface of the first vertical wall 221. The bottom edge of the first tip 236 faces Point A on the first vertical wall 221. Point A is a point on the outer surface of the first vertical wall 221 that is nearest to the bottom edge of the first tip 236. If the tip 236 was tapered, then point A would the part of the vertical wall 221 nearest to the closest point of the tapered first tip 236.

Fluid flows through the horizontal gap between the first tip 236 and the first vertical wall 221. The gap between the first vertical wall 221 and the first tip 236 is narrowest when the first blade 231 is in the closed position and increases as the first blade 231 rotates toward the open position. Thus, the area of the gap between first tip 236 and first vertical wall 221 increases as the first blade 231 opens. Flow through the gap similarly increases as the first blade 231 rotates open due to the increasing area of the gap. The gap remains a horizontal gap (extending horizontally along the X-axis) as the blade 231 rotates due to the first vertical wall 221 being located horizontally across from the first tip 236. The first vertical wall 221 minimizes the area of the gap that fluid can flow through around the first tip 236, such as compared to the choke ring 120, to increase the performance of the damper system 200.

FIGS. 2C-2D illustrate the gap minimization caused by the first vertical wall 221 with respect to the first blade 231. FIGS. 2C-2D shows the first blade 231 positioned at 0 degrees (e.g., closed position), 30 degrees, 60 degrees, and 90 degrees (e.g., open position) of rotation. The distance, and thus area, of the gap between the closest point of the first tip 236 and the first vertical wall 221 increases as the blade rotates open. The smallest distance of the gap is shown as D1, which extends from Point A to the bottom edge of the first tip 236 when the blade is in the closed position. When the first blade 231 is rotated 30 degrees, the closest part of the first tip 236 is horizontally across from Point B on the first vertical wall 221. The gap extends a horizontal distance D2 between the first tip 236 and Point B. When the first blade 231 is rotated 60 degrees, the closest part of the first tip 236 is horizontally across from Point C on the vertical wall 221. The gap extends a horizontal distance D3 between the first tip 236 and Point C. When the first blade 231 is rotated 90 degrees, the closest part of the first tip 236 is horizontally across from Point D on the vertical wall 221. The gap extends a horizontal distance D4 between the first tip 236 and Point D.

Without the first wall, fluid would flow through the available flow area around the first tip 236 of the first blade 231. FIG. 2C includes distances X1, X2, and X3 to illustrate the gap reduction caused by the first vertical wall 221 as compared to a choke ring. For explanation purposes, Point A also represents where a choke ring would terminate if the first vertical wall 221 were replaced with choke ring 120 as shown in FIG. 1C. Distances X1, X2, X3 represent the distance between Point A and the first tip 236 when the first blade 231 positioned at 30 degrees, 60 degrees, and 90 degrees of rotation, respectively. In other words, distances X1, X2, X3 illustrate the size of the gap if a choke ring 120 replaced the wall assembly 220. The Distance X1 is the hypotenuse of a right triangle with Distance D2 being one leg of the triangle, Distance X2 is the hypotenuse of a right triangle with Distance D3 being one leg of the triangle, and Distance X3 is the hypotenuse of a right triangle with Distance D4 being one leg of the triangle. As shown, the Distance D2 is less than Distance X1, Distance D3 is less than Distance X2, and Distance D4 is less than Distance X3. For example, the Distance D2 may be about 24% of Distance X1, the Distance D3 may be about 45% of Distance X2, and the Distance D4 may be about 65% of Distance X3. Thus, the inclusion of the first vertical wall 221 reduces the area (e.g., size) of the gap for fluid to flow through as compared to a choke ring.

FIG. 2D illustrates the gap reduction caused by the first wall 221 as compared to opening the first blade 231 relative to an adjacent third blade 233 held in a closed position without the first vertical wall 221 between the first and third blades 231, 233. Distances Y1, Y2, and Y3 represent the gap that would be present between the first tip 236 of the first blade 231 and the adjacent first tip 236 of the third blade 233 when the first blade 231 is positioned at 30 degrees, 60 degrees, and 90 degrees of rotation, respectively, if the first vertical wall 221 was omitted. As shown, the distance D2 is less than distance Y1, Distance D3 is less than distance Y2, and Distance D4 is less than Distance Y3. Thus, the inclusion of the first vertical wall 221 reduces available area of the gap for fluid to flow through as compared to a damper where one blade is being opened relative to a closed adjacent blade.

The first vertical wall 221 causes a similar gap reduction effect with respect to the first tip 236 of the third blade 233. Additionally, the second vertical wall 222 causes a similar gap reduction effect with respect to the first tips 236 of the second blade 232 and the fourth blade 234.

The first and second vertical walls 221, 222 reduces the change of the area of the gap per degree of rotation as compared to the conventional damper 100. Thus, the first and second vertical walls 221, 222 increases the ability (e.g., performance) of the damper system 200 to control the flow rate of the fluid per unit rotation of blades 231-234. Additionally, the presence of the first and second vertical walls 221, 222 smooths the rate of change of the area of the gap over the rotational range of the blades which improves the ability to the damper system 200 to control the flow. Therefore, the first and second vertical walls 221, 222 result in a damper system 200 with an improved the performance curve with an operating curve that extends over a greater percentage of openness of the of the blades. Additionally, the damper system 200 may be used for improved control of fluids at both low velocities, such as 15 ft/s or less or from 5 ft/s to 15 ft/s, or higher velocity flow, such as 40 ft/s or more or from 40 ft/s to 100 ft/s.

FIG. 3 illustrates an exemplary performance curve of the damper system 200, represented as second performance curve C2, as compared to the first performance curve C1 of the conventional damper 100 illustrated in FIG. 1D. Both performance curves are at various velocities. The Y-axis shows the pressure drop in inches of water and the X-axis represents the percentage of openness of the damper assembly. The portion of the curves between 0% to 20% open and a pressure drop above 0.40 inches of water is not shown.

The first and second blades 231, 232 are in the open position (see FIG. 4C) at 50% open. Thus, the portion of the second performance curve C2 along the X-axis that is less than or equal to 50% open shows the performance of the damper system 200 at various open positions of the first and second blades 231, 232 while the third and fourth blades 233, 234 remain closed. The portion of the performance curve C2 from greater than 50% to 100% open along the X-axis shows the performance of the damper system 200 at various open positions of the third and fourth blades 233, 234 while the first and second blades 231, 232 remain open. All four blades 231-234 are in the open position (as shown in FIG. 4E) at 100% open along the X-axis.

As shown in FIG. 3, the damper system 200 has improved performance as compared to the conventional damper 100 because the second performance curve C2 has a higher pressure drop across the curve as compared to first performance curve C1. For example, the second performance C2 does not reach a pressure drop of 0.05 inches of water until about 85% open while the first performance curve C1 reaches the same value at about 72% open. Additionally, the second performance curve C2 is smoother (e.g., less rate of change in the slope) than the first performance curve C1. For example, the portion of the second performance curve C2 from about 43% open to about 62% open has a more linear slope as compared to the portion of the first performance curve C1 over the same range of openness.

While the performance of the damper system 200 decays as the blades open, the wall assembly 220 increases the performance (e.g, increase the pressure drop) of the damper system 200 across the second performance curve C2 as compared to the conventional damper 100. In other words, the wall assembly 220 improves the damper performance as compared to the benefit in performance caused by a choke ring 120. This increased performance allows for more fine-tuned control of the fluids flowing through the damper system 200.

R1 illustrates an exemplary operating curve R1 of the second performance curve C2 if the damper system 200 is used in a stack to control flue gases. R1 is the portion of the second performance curve that extends from about 55% to about 78% open along the X-axis, which may be a rotational range of the blades during normal operating conditions of the stack assembly 1. As shown, this exemplary operating curve R1 has an increased pressure drop, thus more controllability, over the length of the range as compared to the same range of the first performance curve C1. In some embodiment, the damper system 200 may have an operating curve over a rotational range of the blades (e.g., range along the X-axis) for normal operating conditions within the stack assembly 1 that is 10% to 20% greater than the conventional damper system 1.

In some embodiments, the damper system 200 is incorporated into a stack of a stack assembly, such as stack 3 of the stack assembly 1. The increased controllability of the damper system 200, reflected by the performance curve C2, allows for improved control of combustion in the combustion chamber to reduce emissions. The increase in the controllability of the damper system 200 allows for more precise control of fluid flow. Thus, the damper system 200 can be used to more precisely control conditions, such as the pressure and/or oxygen content, within a combustion chamber to promote more efficient combustion to reduced emissions as compared to conventional damper 100 or other existing damper systems. In some embodiments, the damper system 200 may also be incorporated into a supply line, such as combustible gas supply line 5 or air supply line 6, to control the flow of a gas to the combustion chamber.

Additionally, the damper system 200 eliminates the need for a choke ring 120 to increase the flow velocity passing by the blades to enhance performance as compared to a damper system that does not have a choke ring or vertical walls. As a result, the conduit body 210 and the stack can have a smaller cross-sectional area. A benefit of a reduced stack diameter is reduced materials and construction costs. For example, the elimination of the choke ring 120 may reduce the cross-sectional area of the stack 3 by about 30%, such as about 25%, such as about 20%, such as about 15%, such as about 10%, such as about 5%.

In some embodiments, the damper system 200 may include more than two blades within the wall assembly 220, such as three or more blades. In some embodiments, only one blade may be disposed within the wall assembly 220. In some embodiments, multiple blades may be disposed exterior of the wall assembly 220 similarly to the third and fourth blades 233, 234.

In some embodiments, a small gap (e.g., clearance) may be present between the first tip 236 and the first vertical wall 221 when the first blade 231 is closed such that a small amount of flow is permitted through the gap while the first blade 231 is in the closed position. In some embodiments, the first tip 236 may have a sealing member to seal against the first vertical wall 221 when the first blade 231 is in the closed position to prevent or substantially prevent fluid flow between the first vertical wall 221 and the first tip 236. A sealing member may be coupled to the first tip 236 of the other blades 232, 233, 234 to similarly seal against an adjacent vertical wall.

In some embodiments, the first and second vertical wall 221, 222 have a height that is equal to the width of the blades when the blades are in the closed position.

FIG. 4A illustrates the damper system 200 shown in FIG. 2A to describe the features and operation of the actuator assembly 250. The actuator assembly 250 is also shown in FIG. 4F, which is an enhanced view of the circled region in FIG. 4A. The actuator 250 includes a linkage 410 that interfaces with a corresponding slot member 431-434 of each shaft 241-244. The linkage 410 may be a bar linkage that is made of metal, such as steel. The linkage 410 includes a first segment 411, a second segment 412, and a third segment 413. The first segment 411 and second segment 412 extend outwardly from opposing sides of the third segment 413. The first and second segments 411, 412 are substantially parallel with one another and are separated from each other by the third segment 413. The linkage includes a first pin 421, a second pin 422, a third pin 423, a fourth pin 424, and a fifth pin 425. The first pin 421 and third pin 423 are located on the first segment 411, the second pin 422 and fourth pin 424 are located on the second segment 412, and the fifth pin 425 is located on the third segment 413. In some embodiments, each of the pins 421-425 protrude from the same side of the linkage 410 as shown in FIGS. 4A and 4F.

Each shaft 241-244 includes a respective slot member 431-434 at one end. The first slot member 431 is attached to the first shaft 241 in an orientation that mirrors the attachment of the second slot member 432 to the second shaft 242. The third and fourth slot members 433, 434 are similar in a mirrored orientation with respect to one another. The first slot member 431 includes a first slot 441, the second slot member 432 includes a second slot 442, the third slot member 433 includes a third slot 443, and the fourth slot member 434 includes a fourth slot 444. The first pin 421 is disposed in the first slot 441, the second pin 422 is disposed in the second slot 442, the third pin 423 is disposed in the third slot 443, and the fourth pin 424 is disposed in the fourth slot 444. A nut may be threaded onto the end of the pin 421-425 to retain the pin in the respective slot.

The slots 441-444 are sized and shaped to facilitate rotating the corresponding shaft 241-244 to a desired position in response to the movement of the respective pin 421-424 disposed therein. Each of the slots 441-444 includes a first portion 445 (e.g., straight portion of the slot) and a second portion 446 (e.g., curved portion of the slot). The first portion 445 accommodates the movement of the respective pin 421-424 as the linkage 410 is translated by a drive member 450. This includes allowing the respective pin 421-424 slide along the first portion 445 without causing the corresponding blade to rotate. Each pin 421-424 engages with the second portion 446 to facilitate rotating the respective blade 231-234. The second portion 446 is shaped to facilitate the rotation of the corresponding blade as the corresponding pin 421-424 slides along the second portion 446. Additionally, the corresponding pin 421-424 of the linkage 410 may be engaged with the end of the second portion 446 as the linkage 410 is translated, causing the corresponding blade to rotate.

The drive member 450, such as an elongated arm, is used to move the linkage 410 to change the position of the blades 231-234. The drive member 450 may be attached to the exterior of the conduit, such as a burner stack 3 or a duct of air-handling equipment, and may be operated by a single actuator, such as a hydraulic motor, an electric motor, a pneumatic motor, or a cable and winch mechanism. In some embodiments, the drive member 450 is coupled to the exterior of the conduit body 210. The drive member 450 includes a drive slot 451, and the fifth pin 425 is disposed within the drive slot 451. The fifth pin 425 interacts with the drive slot 451 such that the movement of the drive member 450 causes the linkage 410 to move.

A controller may be used to operate the actuator used to move the drive member 450 to move the blades 231-234 between positions. The controller as described herein may be a single centralized controller or may be a distributed controller including a plurality of individual control units. The controller may include a central processing unit (CPU), a memory and, for example, support circuits. To facilitate control of the actuator assembly 250, the CPU may be one of any form of general-purpose computer processor that can be used in an industrial setting for controlling various components and sub-processors. For example, the controller may be a computer at an employee workstation near the stack assembly 1 that can adjust the blade position in response to a manual input from a person or automatically in response to a change in a condition within the combustion chamber 2. The memory may be coupled to the CPU. The memory, or a computer readable medium, may be one or more readily available memory devices such as random-access memory, read only memory, a floppy disk, a hard disk, or any other form of digital storage either local or remote. The support circuits may be coupled to the CPU for supporting the processor in a conventional manner. The circuits in question include cache, power supplies, clock circuits, input/output circuitry and related subsystems, and the like. In some embodiments, the actuator assembly 250 is manually controlled. For example, a winch and cable mechanism may be operated by hand to cause the drive member 450 to move in order to change the position of the blades 231-234.

FIGS. 4A-4E illustrates a sequence of using the actuator assembly 250 to open the blades 231-234. FIG. 4A shows the blades 231-234 in the closed position. The linkage 410 is shown in a first position. The first slot member 431 is pointing downward while the second slot member 432 is pointing upwards. The third and fourth slot members 433, 434 are both pointing in the same direction (towards the left side of the damper system 200). The third pin 423 and fourth pin 434 are each engaged with end the first portion 445 of the third slot 443 and fourth slot 444, respectively.

The linkage 410 moves to the right as the drive member 450 is rotated in a counter-clockwise direction. Each pin 421-424 slides along the respective slot 441-444 as the linkage 410 moves. As the drive member 450 rotates away from the position shown in FIG. 4A towards the position shown in FIG. 4B, the first and second pins 421, 422 slide towards the second portion 446 of the first and second slot members 431, 432 respectively and begin opening the first and second blades 231, 232. The third and fourth pins 423, 424 slide along the first portion 445 towards the second portion 446 of the third and fourth slots 443, 444, respectfully; but the third and fourth blades 233, 234 remain closed.

FIG. 4B shows the first blade 231 and second blade 232 both at about 45 degrees open (e.g., halfway open) while the third blade 233 and fourth blade 234 remain closed. The linkage 410 is shown in a second position that is to the right of the first position shown in FIG. 4A. The first and second pins 421, 422 are both shown disposed in the second portion 446 of the first and second slots 441, 442, respectfully, while the third and fourth pins 423, 424 are disposed in the first portion 445 of the third and fourth slots 443, 444, respectively.

The drive member 450 may be further actuated to rotate in a counter-clockwise direction to further open the first and second blades 231, 232 while the third and fourth blades 233, 234 remain closed. For example, as the drive member 450 is rotated away from the position shown in FIG. 4B towards the position shown in FIG. 4C, the first and second pins 421, 422 are engaged with the second portion 446 of the first and second slot members 431, 432 respectively and further cause the first and second blades 231, 232 to open. The third and fourth pins 423, 424 continue slide along the first portion 445 and towards the second portion 446 of the third and fourth slots 443, 444, respectfully; but the third and fourth blades 233, 234 still remain closed.

FIG. 4C shows the first blade 231 and second blade 232 both in the open position (90 degree of rotation) while the third blade 233 and fourth blade 234 remain closed. The linkage 410 is shown in a third position that is to the right of the second position shown in FIG. 4B. The first and second pins 421, 422 are both shown disposed in the second portion 446 of the first and second slots 441, 442, respectfully, while the third and fourth pins 423, 424 are located at or near the transition of the second portion 446 of the third and fourth slots 443, 444, respectively. Additionally, the second slot member 432 and fourth slot member 434 have been rotated such that each member is pointing towards the other with a clearance therebetween. The slot members 431-434 are each sized to avoid contact with an adjacent slot member as the each slot member 431-434 rotates.

The drive member 450 may be further rotated in a counter-clockwise direction to open the third and fourth blades 233, 234 while the first and second blades 231, 232 remain fully open.

For example, as the linkage 410 is moved away from the third position in FIG. 4C to a fourth position shown in FIG. 4D, the first and second pins 421, 422 slide along the first portion 445 away from second portion 446 of the first and second slot members 431, 432 respectively. The first and second blades 231, 232 remain in the open position as the first and second pins 421, 422 slide along the first and second slots 441, 442. The third and fourth pins 423, 424 slide along the second portion 446 of the third and fourth slots 443, 444, respectfully which causes the third and fourth blades 233, 234 to open.

FIG. 4D shows the first blade 231 and second blade 232 both remained in the open position while the third blade 233 and fourth blade 234 are now both at 45 degrees open. The linkage 410 is shown in a fourth position that is to the right of the third position shown in FIG. 4C. The first and second pins 421, 422 are both shown disposed in the first portion 445 of the first and second slots 441, 442, respectfully, while the third and fourth pins 423, 424 are disposed in the second portion 446 of the third and fourth slots 443, 444, respectively.

The drive member 450 may be further rotated in a clockwise direction to continue to open the third and fourth blades 233, 234 while the first and second blades 231, 232 remain open.

For example, as the linkage 410 is moved away from the fourth position in FIG. 4D to a fifth position shown in FIG. 4E, the first and second pins 421, 422 slide along the first portion 445 away from second portion 446 of the first and second slot members 431, 432 respectively. The first and second blades 231, 232 remain in the open position as the first and second pins 421, 422 slide along the first and second slots 441, 442. The third and fourth pins 423, 424 slide along the second portion 446 of the third and fourth slots 443, 444, respectfully which causes the third and fourth blades 233, 234 to further open to the fully open position shown in FIG. 4E.

FIG. 4E is a partial perspective view that shows all four blades 231-234 in the fully open position. The linkage 410 is shown in the fifth position that is to the right of the fourth position shown in FIG. 4D. The first and second pins 421, 422 are both shown engaged with the end of in the first portion 445 of the first and second slots 441, 442, respectfully, while the third and fourth pins 423, 424 are disposed at or near the transition between the first portion 445 and second portion 446 of the third and fourth slots 443, 444, respectively.

The blades 231-234 are closed by rotating the drive member 450 in a clockwise direction, which will cause the third and fourth blades 233, 234 to reach the fully closed position before the first and second blades 231, 232 begin to close.

The drive member 450 may be rotated to change the position of the first and second blades 231, 232 repeatedly without opening the third and fourth blades 233, 234. For example, the drive member 450 may move the first and second blades 231, 232 to one or more open positions, such as 30 degrees to 45 degrees open, and then close the first and second blades 231, 232 while the third and fourth blades 233, 234 remain closed.

In some embodiments, the actuator assembly 250 is configured to open the first and second blades 231, 232 and the third and fourth blades 233, 234 in a parallel fashion rather than the opposed fashion shown in FIGS. 4A-4E. In some embodiments, the actuator assembly 250 is configured to rotate the first and second blades 231-232 and third and fourth blades 233-234 asynchronously. In some embodiments, the actuator assembly 250 is configured to open the third and fourth blades 233, 234 before opening the first and second blades 231, 232. Additionally, the actuator assembly 250 as show and described in FIG. 4A-4E is one exemplary embodiment of an actuator assembly to cause a staged opening of blades (e.g., opening the first and second blades 231, 232 prior to opening the third and fourth blades 233,234). For example, the actuator assembly could have a linkage translated by a drive member that has a cam that interacts with a respective follower of each blade. The cam and followers may be arranged to facilitate a staged opening of the blades. A single actuator may be used to operate the drive member to translate the linkage.

FIG. 5 illustrates a cross-sectional view of a damper system 500. The damper system 500 has similar components as the damper system 200 as indicated by the reference signs without reciting the description of these components of the damper system 200 for brevity. The wall assembly 220 of damper system 500 includes a third vertical wall 523 disposed between the first vertical wall 221 and second vertical wall 221 and further disposed between the opposing second tips 237 of the first blade 231 and second blade 232. Placing a third vertical wall 523 between the opposing second tips 237 enhances the controllability of the damper system in a similar manner as the first and second vertical walls 221, 222 because the third vertical wall 523 reduces the area available for fluid to flow around the second tip 237. In other words the third wall 523 minimizes the area of the gap between the second tip 237 and the third wall 523 as compared to when the third wall is not present between the opposing second tips 237. As a result, the reduced area available for the fluid to flow around the second tips 237 further improves the damper performance.

In some embodiments, a damper system includes three or more blades disposed in the wall assembly 220 that are rotatable by an actuator assembly. For example, the damper system may include more than two blades between the first and second vertical walls disposed in the conduit body 210. For example, the damper system may include three, four, or more blades between the first and second vertical walls. A vertical wall may be disposed between the two or more blades disposed between the first and second vertical walls. For example, four blades may be disposed between the first and second vertical walls with three additional vertical walls disposed therebetween, each additional vertical wall being disposed between two adjacent blades.

In some embodiments, the damper system is a two blade damper with a single vertical wall disposed between a first and second blade within a conduit body. A single actuator assembly operated by a single actuator may be used to rotate the two blades. Each blade can be rotated synchronously or a synchronously in an opposed or parallel fashion.

FIG. 6 illustrates a top view of damper system 600. The damper system 600 has similar components as the damper system 200 as indicated by the reference signs without reciting the description of these components of the damper system 200 for brevity. Damper system 600 has a wall assembly 220 that is a ring 620. The ring 620 may be a rectangular ring as shown in FIG. 6. The ring 620 includes the first vertical wall, 221, the second vertical wall 222, and two side vertical walls 624 connecting the first and second vertical walls 221, 222 together. The ring 620 is attached to the interior surface of the conduit body 210 by plates 612. In some embodiments, the ring 620 may be welded directly to the conduit body 210 or attached to the conduit body 210 by a plurality of fasteners. The inner surface of the walls of the ring 620 define an opening 625. The first and second blades 231, 232 are disposed within the opening 625 of the ring 620. The third and fourth blades 233, 234 are disposed in the body opening 211 on opposing sides of the ring 620. As shown, the third blade 233 is disposed between the inner surface of the conduit body 210 and the first wall 221 and the fourth blade 234 is disposed between the inner surface of the conduit body 210 and the second wall 222. In other words, the first and second blades 231, 232 are disposed in the interior of the ring 620 and the third and fourth blades 233, 234 are disposed exterior of the ring 620. In some embodiments, the ring 620 may include a third vertical wall between the first blade 231 and second blade 232.

The plates 612 block flow between the inner surface of the conduit body 210 and the side walls 624. In some embodiments, the plates 612 may be omitted. The first shaft 241 and the second shaft 242 may extend through one or more ports (not shown) formed in the side walls 624.

In some embodiments, the ring 620 is sized such that the first and second vertical walls 221, 222 do not fully span across opening 211 of the conduit body 210 such that each wall 221, 222 contact opposite sides of the interior of the conduit body 210. Instead, the first and second vertical walls 221, 222 partially span across the opening 211.

The damper system 600 also includes an actuator assembly 650. The actuator assembly 650 may be configured to rotate the blades in a staged fashion, such as rotating the third and fourth blades 233, 234 to the open position after the first and second blades 231, 232 are rotated open. The actuator assembly 650 may be actuator assembly 250.

In some embodiments, the damper system may include one blade or more than two blades within a wall assembly that is a ring disposed in the conduit body. For example, the damper system may include three, four, or more blades within the ring and one or more blades disposed exterior of the ring. The ring may include an additional vertical wall between adjacent blades disposed within the ring.

The damper system disclosed herein are not limited to applications involving flue gases, stacks, or burners. For example, the damper systems can be included in other industrial or home applications to control fluid flow. For example, the damper systems may be incorporated into a Heating, Ventilation, and Air conditioning (HVAC) system. The damper systems may be incorporated into a duct, chimney, VAV box, air handler, or other air-handling equipment.

In some embodiments, the one or more vertical walls of the wall assembly have a height that is equal to or greater than the width of a blade, such as the widest blade, when the blade are in the closed position.

In some embodiments, the first and second walls have a height less than the width of a blade, such as the widest blade, in the closed position. The height being selected for a desired performance properties over a range of openness of the blades. For example, the one or more vertical walls of the wall assembly may have a height that is half or about half the width of a blade. As another example, the one or more vertical walls of the wall assembly may have a height that is one-third or about one-third of the width of a blade. As another example, the one or more vertical walls of the wall assembly may have a height that is one-fourth or about one-fourth of the width of a blade. The height may be selected based on a vertical distance of travel of the first tip over a desired rotational range of the blade such that the first tip is always horizontally across from the adjacent vertical wall as the blade rotates over the range, the selected height being less than the height of the blade in the open position. In some embodiments, the height of each vertical wall may be between greater than or equal to 20% of the blade width, such as 30% of the blade width, such as 40% of the blade width, such as 50% of the blade width, such as 60% of the blade width, such as 70% of the blade width, such as 80% of the blade width, such as 90% of the blade width, such as 99% of the blade width. In some embodiments, the height of each vertical wall may be between 20% and 50% of the width of the blade, such as 30% of the width, such as 40% of the width. In some embodiments, the height of each vertical wall may be between 70% to 100% of the width of the blade, such as 75% of the width, such as 80% of the width, such as 85% of the width, such as 90% of the width, such as 95% of the width. In some embodiments, the height of each vertical wall may be between 85% and 100% of the width of the blade.

In some embodiments, the shaft of the blade is eccentric to the centerline of the blade. In other words, a majority of the width of a blade may be on one side of the shaft. The wall assembly may be positioned in the conduit body to accommodate this eccentricity such that the first tip of the blade is always horizontally across from an adjacent vertical wall over a desired rotational range of the blade. For example, the mid-point of each vertical wall may be vertically displaced as opposed to the transverse axis that runs through the width of the blade.

In some embodiments, the one or more vertical walls have a width that is between 0.5 to about 2.5 times the width of the conduit body 210. In some embodiments, the one or more vertical walls have a width that is equal to about the thickness of the blades. In some embodiments, the one or more vertical walls may have a width that is between about an eighth of an inch to about 2 inches.

In some embodiments, the damper system include multiple actuator assemblies instead of a single actuator assembly that opens and closes the blades. For example, each blade may be operated by a separate actuator assembly. In other embodiments, one actuator assembly may be used to control the blades located within the interior of the wall assembly while one or more additional actuator assemblies are used to control the blades located to the exterior of the wall assembly. In some embodiments, each actuator assembly has a single actuator, such as an electric motor, hydraulic motor, pneumatic motor, or a winch and cable mechanism, used to operate the actuator assembly to rotate the associated blades.

In some embodiments, the conduit body 210 is the conduit that the blades of the damper system are installed within. In other words, the blades and their shafts and the one or more vertical walls of the wall assembly, such as wall assembly 220, are installed directly into a portion of the conduit, such as being integrated within the stack 3.

While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

DAMPER SYSTEM

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CPC

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