Title of Invention	"A MODULAR DESIGN ROTOR FOR USE IN AIRPREHEATER"
Abstract	This invention relates to a modular design rotor for use in airpreheater comprising a rotor post and lug assembly , an upper header plate and a lower header plate positioned at two ends of a cylindrical shaped post shell .

Full Text

The present invention relates to modular design rotor used and in Airpreheater. The invention particularly relates to modular design rotor for 24.5 - 26.5 size Airpreheater. FIELD OF INVENTION: Rotary Regenerative Airpreheaters are used in Thermal power stations / Industrial applications to transfer the heat from the flue gas leaving boiler / furnace to the entering combustion air through air and gas streams. The invention includes Rotary Regenerative heat exchangers generally used as Airpreheaters and more particularly to an improved modular design rotor used in Airpreheater for easy manufacturing of rotor post and modules with improved quality and productivity, eliminating field welding of rotor at site and also to reduce the erection time of the Airpreheater at site. PRIOR ART: The present invention relates to Rotary Regenerative heat exchangers generally used as Airpreheaters and more particularly to an improved modular design rotor used in Airpreheater for easy manufacturing of rotor post and modules with improved quality and productivity, eliminating field welding of rotor at site and also to reduce the erection time of the Airpreheater at site. A Rotary Regenerative Airpreheater transfers sensible heat from the flue gas leaving a boiler to the entering combustion air through regenerative heat transfer surface in a rotor which turns continuously through air and gas streams. The cylindrical rotor is disposed on a horizontal or vertical central rotor post divided into a plurality of sector shaped compartments by a plurality of radial partitions, referred to as diaphragms, extending from the rotor post to the outer peripheral shell of the rotor. These sector shaped compartments are loaded with heat exchange baskets which contain the mass of heat absorbent material commonly formed of stacked plate-like heat transfer elements. In a typical Rotary Regenerative heat exchanger, the hot flue gas and the combustion air enter the rotor shell from opposite ends and pass in opposite directions over the heat exchange material housed with in the rotor. Consequently, the cold air inlet and the cooled gas outlet are at one end of the heat exchanger, referred to as the cold end, and the hot gas inlet and the heated air outlet are at the opposite end of the heat exchanger, referred to as the hot end. The Airpreheater is divided in to a flue gas side or sector and one or more combustion air sides or sectors by sector plates. Flexible radial seals on the rotor, usually mounted on the top and bottom edges of the diaphragms, are in close proximity to these sector plates and minimize leakage of gas and air between sectors to separate the air and flue gas streams from each other. Likewise, a rotor shell is mounted to the outboard ends of the diaphragms, forming the periphery of the rotor, to prevent the air and gas streams from flowing through the peripheral ends of the sectors and bypassing the heat transfer surface. Circumferential seals seal the gap between the rotor and the rotor housing to prevent bypass flow through the annulus formed between the rotor and the rotor housing. Presently, 24.5 - 26.5 size Airpreheater is used with a non-modular (Conventional) design. In the existing design the rotor is built by radially extending the diaphragm plates from the rotor post and shell plates located at the peripheral of rotor and then despatched to site as segments. Similarly, the heating elements are manufactured and despatched to site separately as baskets. In modular design, the elements are manufactured and the heating element baskets are assembled in the module in the shop and despatched to site as modules. The manufacturing time to fabricate the non-modular rotor is much more when compared to modular design rotor. Further, the segments are assembled at site in the rotor, heavy welding of rotor is involved and then the elements are loaded in the rotor it took more time to assemble the baskets in the rotor. In order to avoid the costly packing, transportation of basketed elements to site, storage of elements at site and also to reduce the erection time, it is necessary to develop the modular design rotor for 24.5 - 26.5 size Airpreheater. OBJECTS OF INVENTION: In the existing conventional design the rotor is built by radially extending the diaphragm plates from the rotor post and shell plates located at the peripheral of rotor and then despatched to site as segments. Similarly, the heating elements are manufactured and despatched to site separately as baskets. In modular design, the elements are manufactured and the heating element baskets are assembled in the module in the shop and despatched to site as modules. The manufacturing time to fabricate the non-modular rotor is much more when compared to modular design rotor. Further, the segments are assembled at site in the rotor, heavy welding of rotor is involved and then the elements are loaded in the rotor it took more time to assemble the baskets in the rotor. In the modular design, the elements are manufactured and assembled in the modules in the shop and despatched to site as modules. The rotor post and modules are despatched to site separately. The modules are assembled with rotor post by using pin and locating pin at site. And thus heavy welding of rotor is eliminated and also 40% of the erection time reduced to install the Airpreheater at site. STATEMENT OF INVENTION: In the modular design, the Rotor post construction is comparatively simpler than the non-modular design and also Jigs and Fixtures are used for manufacture, both quality and productivity could be increased. The inventive concept in the Modular design is that the heating elements are manufactured and loaded into the modules in the shop itself and then the Rotor post and the modules are dispatched to site and the modules are assembled with rotor post by using pin and locating pin, where as in the non-modular design, the rotor is built by radially extending the diaphragm plates from the rotor post and shell plates located at the peripheral of rotor and then dispatched to site as segments and the segments are assembled with rotor at site through heavy welding, thus the field welding of rotor is very nearly eliminated in the modular design. And also the costly packing of heating elements for transportation and storage of elements required at site can be eliminated. Similarly, there will be a savings of about 40% to 45% of erection time, which will reduce the installation cost in the case of modular design. Thus the present invention provides a modular design rotor for use in Airpreheater comprising a rotor post and lug assembly an upper header plate and a lower header plate positioned at two ends of a cylindrical shaped post shell. DETAILED DESCRIPTION OF THE INVENTION: In the new design, the Rotor post and Lug assembly (04) were designed for 24.5 - 26.5 size Airpreheater considering the available standard lug plates and header plates (01) & (02) and also manufacturing feasibility. The modules (05) are designed and fabricated by welding the diaphragm plates with lug assembly (04) on both sides and the shell plate is connected with the diaphragm plates peripherally. Then the modular drawing was prepared for 24.5 size Airpreheater. The modular design was verified by doing modular analysis. Modular analysis was made by calculating the bearing stress, shear stress and total stress for Lug plates, Header plates (01) & (02), Pin (06) and Post shell (03). The calculated stress values were compared with the allowable stress values and are well within the limits. The elements are manufactured and assembled in the modules (05) in the shop and despatched to site as modules. The rotor post and modules (05) are despatched to site separately. The modules are assembled with rotor post by using pin (06) and locating pin (07) at site. And thus heavy welding of rotor is eliminated at site. Modular design rotor post for Airpreheater is shown in the accompanying drawing. The following are the advantages of the modular design rotor used in the Airpreheater compared to non-modular design. 1. In the Modular design, the Rotor post and the modules are dispatched to site and the modules are assembled with rotor post by using pin and locating pin, where as in the non-modular design, the rotor is built by radially extending the diaphragm plates from the rotor post and shell plates located at the peripheral of rotor and then dispatched to site as segments and the segments are assembled with rotor at site through heavy welding, thus the field welding of rotor is very nearly eliminated in the modular design. By using the modular design rotor there will be a savings of about 40% to 45% of erection time, which will reduce the installation cost and overall cycle time and it is not there in the non-modular design rotor. In the modular design, the heating elements are loaded into the modules in the shop itself, where as in the non-modular design, the heating elements are dispatched to site separately and loaded in the rotor at site and hence, the costly packing required for transportation and storage of heating elements required at site can be eliminated. In the modular design, the Rotor post construction is comparatively simpler than the non-modular design and also Jigs and Fixtures are used for manufacture, both quality and productivity could be increased. WE CLAIM: 1. A modular designed rotor use in airpreheater comprising a rotor post and lug assembly (04), an upper header plate (02) and a lower header plates (01) positioned at two ends of a cylindrical shaped post shell (03). 2. A modular designed rotor use in airprehater as claimed in Claim 1 wherein the heating elements are loaded in to the modules (05) of said rotor at shop. 3. A modular designed rotor for use in airpreheater as claimed in Claim 1 or 2 wherein said rotor post and the modules (05) are dispatched to site separately and are assembled by using pin (06) and locating pin (07) at site, thus field welding of rotor is eliminated. 4. A modular designed rotor for use in airpreheater substantially as herein described and as illustrated in the drawings accompanying the Complete Specification.

Documents:

177-del-2003-abstract.pdf

177-del-2003-claims.pdf

177-del-2003-complete specification (granted).pdf

177-del-2003-correpondence-others.pdf

177-del-2003-correpondence-po.pdf

177-del-2003-description (complete).pdf

177-del-2003-drawings.pdf

177-del-2003-form-1.pdf

177-del-2003-form-13.pdf

177-del-2003-form-19.pdf

177-del-2003-form-2.pdf

177-del-2003-form-3.pdf

177-del-2003-form-4.pdf

177-del-2003-form-5.pdf

177-del-2003-gpa.pdf