Patent Application
20090032385
This invention relates to coke ovens, and in particular damper baffles used in the ventilation system of coke ovens.
Damper block baffles inside the ventilation systems of coke ovens regulate air flow through the ovens to control oven temperatures. Heretofore, damper block baffles consisted of a plurality of refractory damper blocks stacked atop a lift frame that is raised and lowered within the ventilation duct to open and close the air passage. The refractory damper blocks used in the damper block baffles are large heavy pre-cast shapes designed to withstand the high temperatures and act as a thermal barrier. Because of the weight and size of the damper blocks, the baffles require large hydraulic pistons to raise and lower the damper block baffles within the ventilation ducts.
Because the extreme heat from the coke ovens, refractory damper blocks deteriorate over time and must be routinely replaced. Replacing the bulky and heavy refractory damper blocks is labor intensive and cumbersome within the confined area of a coke oven ventilation system. Typically, the entire damper block baffle is disconnected from the hydraulic lift mechanism and lowered out of the ventilation ducts using multiple winches. Once lowered and accessible, used refractory damper blocks must be manually unstacked and hauled out, before replacement blocks can be inserted and stacked onto the lift frame. Multiple people are often required to handle the heavy cumbersome refractory damper blocks. In addition, the often crumbling deteriorated refractory damper blocks leave debris in and around the ventilation system of the coke ovens.
The present invention seeks to provide a light-weight damper baffle for use in coke ovens, which eliminates the need for the heavy and cumbersome refractory damper blocks. An embodiment of the damper baffle of this invention includes a U-shaped sub-frame and a temperature resistant insulation damper mat draped over and secured upright to the sub-frame. The damper mat is a thick sheet of silica needle mat, which provides the thermal barrier of the damper baffle. The sub-frame is a bent high temperature steel rod which is bolted directly to the base plate of a conventional lift frame and lift mechanism. Two pairs of support plates secure and support the mat over the sub-frame in an upright orientation. The silica needle mat used in the damper baffle of this invention replaces the bulky refractory damper blocks of conventional damper baffles. Because the silica needle mat is a fraction of the weight of the refractory damper block, the weight of the present damper baffle is significantly less than conventional damper baffles. Consequently, weight savings means that the present damper baffle can be replaced in less time, with less labor, more safely and with less difficulty.
These and other advantages of the present invention will become apparent from the following description of an embodiment of the invention with reference to the accompanying drawings.
The drawings illustrate an embodiment of the present invention, in which:
As best shown in
Damper mat 20 provides the thermal barrier of damper baffle 10. Damper mat 20 is thick sheet of highly temperature resistant fabric, such as the silica needle mat supplied by Pyro Shield, Inc. of Crown Point, Ind. The silica needle mat material of damper mat 20 is made from continuous filament silica that has a uniform diameter of approximately 8 micron, which makes the material non-respirable and durable insulator for high temperature applications. While silica needle mat provides the desired thermal insulation, durablity and light weight, damper mat 20 may be constructed from other high temperature fabrics and materials within the teachings of this invention.
As shown, damper mat 20 is draped over sub-frame 12 and overlapped in multiple layers. Generally, damper mat 20 is at least two inches thick. This thickness provides the necessary thermal barrier and sufficient structural integrity to hold damper mat 20 upright over sub-frame 12. While damper mat 20 is illustrated as being overlapped back and forth to provide the desired thermal barrier, the same result can be produced by simply using a silica needle mat of greater thickness without overlapping the mat. Damper mats 20 is sandwiched between two pairs of steel support plates 16 and 18 sandwich damper mat 20 to hold damper mat 20 upright in place over sub-frame 12 and prevent the mat from sagging. Each pair of support plates 16 and 18 are secured together by bolts and nuts 17 which extend through damper mat 20 and hold the mat to sub-frame 12.
One skilled in the art will note that the damper baffle embodying the present invention provides several advantages over refractory block damper baffles. The damper baffle eliminates the need for the cumbersome refractory baffle blocks, which deteriorate and crumble, leaving debris in and around the ventilation system of the coke oven battery. By substituting a silica needle mat in place of the bulky refractory damper blocks, the present damper baffle greatly reduces the time and labor required to replace the damper baffles within the ventilation systems of coke oven batteries. The need to manually un-stack and stack, remove and deliver the cumbersome refractory damper blocks is eliminated. Because the silica needle mat is a fraction of the weight of the refractory damper block, the damper baffle of this invention can be handled easily within the confined area of the coke oven battery with two or fewer people. Replacing the heavy refractory damper blocks with the silica need mat, also reduces the chances of injury from the stacked deteriorating damper blocks falling from the lift frame on laborers replacing the baffles. Conventional lift frames can be modified to use the damper baffles of this invention by simply cutting two holes to receive the ends of the sub-frame. Once the lift frames are modified, replacing damper baffles can be accomplished in short order with only common tools.
The embodiment of the present invention herein described and illustrated is not intended to be exhaustive or to limit the invention to the precise form disclosed. It is presented to explain the invention so that others skilled in the art might utilize its teachings. The embodiment of the present invention may be modified within the scope of the following claims.
