WEAR PROOF BATWINGS
Publication Date: 2013-Jun-06
The IP.com Prior Art Database
This publication discloses designs which solve the problem of wear to the parent metal of the batwing tab forward mount of a transition duct in a gas turbine which connects to the “bull horn” support bracket. In one design, a U-shaped wear insert is used in the slot on the batwing tab connecting to the support bracket and in the other design, the slot is replaced by a drilled hole and a wear insert is placed in this hole. In both the designs, the wear inserts are tack welded in place and can be easily replaced when required. The wear inserts can be made of a suitable high temperature alloy such as L-605. The designs are expected to provide advantages in manufacturing and in operation and maintenance.
This publication relates to the design of forward mount of a transition duct in a gas turbine. The transition duct in a gas turbine is a tubular member which connects a combustor of the combustion system of the gas turbine to the first stage of the turbine. The transition duct, at its inlet end is positioned adjacent the combustor exit by a support bracket. An example of a transition duct inlet and support bracket is shown in Figure 1. “Batwing” tabs welded to the transition duct body are bolted to the combustor casing via a “bull horn” bracket. For ease of maintenance, each of the batwing tabs is provided with a slot in which a bolt is inserted for attachment to the support bracket. Due to the vibrations experienced by the combustion system and adjacent transition duct, frictional contact at the interface region between the support bracket and transition duct has been known to create excessive wear, especially on the batwing tabs, resulting in premature repair or replacement of the batwings.
Figure 1: Transition piece forward sleeve assembly with batwing tabs connected to the bull horn bracket
BRIEF DESCRIPTION OF DRAWINGS
The wear proof batwing design is explained with reference to the following figures
Figure 1 shows the transition piece forward sleeve assembly with batwing tabs connected to the bull horn bracket
Figure 2 shows slotted batwing design
Figure 3 shows the wear insert installed in batwing slot
Figure 4 shows batwing with drilled hole and corresponding wear insert
This publication discloses two ways of solving the problem of wear to the parent metal of the batwing tabs, a) by using a U-shaped wear insert in the slot on the batwing tab connecting to the support bracket and b) by eliminating the slot on the batwing, which is prone to wear, and replacing it with a drilled hole and a wear insert into said hole. The first method is illustrated in Figures 2 and 3. Figure 2 shows the design of the slot in the batwing, which is the same as that in the standard configuration, except that the slots are machined wider and deeper to accommodate the U-shaped wear insert shown in Figure 3. The U-shaped wear insert is shown tack welded in position in Figure. 3.
Figure 2: Slotted batwing design
Figure 3: Wear insert installed in batwing slot
This insert is replaceable as well, in the event that the transition piece needs repair. The wear insert is to be placed in the slot to prevent the b...