FIELD OF THE INVENTION

The present invention relates to an apparatus for lifting and positioning coal nozzles inside the coal compartments in supercritical windboxes for fuel firing in power plants.
BACKGROUND OF THE INVENTION
In power plants, the windboxes are used for fuel firing inside the furnace. The coal nozzles are assembled in each of compartments of windbox modules, which supplies pulverized coal along with the primary air. The coal nozzle is a casting component provided with a nozzle tip of stainless steel material at one of its ends, which oscillates in one axis at an angle of 30° along its pivot.
These coal nozzles have been assembled over a nylon belt, which in turn is connected to an EOT crane apparatus. It was noticed that the nozzle tip has been sliding on anyone of the sides which poses a serious problem during positioning of the nozzle inside the compartment. The dimensions of the coal nozzle is generally 787 X 685 X 584 mm and the weight of the nozzle under study is 8560kgs. Moreover, this operation was found as highly unsafe to the workmen as the nozzle has to be lifted to the windbox height. It takes about 30 minutes to lift and position the coal nozzle inside the windbox compartment using the nylon belt.

Hence there is a need to find out a safe method of handling coal nozzles with reduction in man power and time; a new lifting apparatus is developed for handling purpose.
OBJECT OF THE INVENTION
It is therefore an object of the invention to propose an apparatus for lifting and positioning coal nozzles inside the coal compartments in supercritical windboxes for fuel firing in power plants.
Another object of the invention is to propose an apparatus for lifting and positioning coal nozzles inside the coal compartments in supercritical windboxes for fuel firing in power plants, which is operationally safer and reduces cycle time.
SUMMARY OF THE INVENTION
Accordingly, there is provided an apparatus for lifting and positioning coal nozzles inside the coal compartments in supercritical windboxes for fuel firing in power plants, the device comprises a plurality of plates (02) vertically welded at two ends

of a horizontally placed first plate (01), the plurality of plates (02) be,ng perpendicular to each other at same height at both ends a second plate (03) welded to said first of plate (01) at the center; a third plate (04) each other at same height at both ends; a welded at the back side of plate (01); a plurality of fasteners (05) provided on each of said plurality of plates (02) to clamp the coal nozzle on to the lifting apparatus. The lifting apparatus is positioned inside the coal nozzle (06) and movement of the nozzle (06) arrested on all sides by locking the fasteners (05). Thus the drawbacks said in the prior art are eliminated.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 - is a block diagram of an apparatus used for positioning the coal nozzle in windbox compartments according to the invention.
Figure 2 - shows the lifting apparatus of Figure 1 which has been positioned inside the coal nozzle.
DETAILED DESCRIPTION OF THE INVENTION
The embodiment here in and the various features and advantageous details thereof are explained with references to the accompanying figure - 1.

Identical fasteners (05) at opposite locations are provided on either side of the plates (02) and welded together as shown in Figure 1. The welded plates (02) are kept perpendicular to each other, which are subsequently positioned into the coal nozzle tip. The welded plates (02) are provided with fasteners (05) help to arrest the horizontal movement of coal nozzle during lifting and act as an apparatus to lift as well. The fasteners (05) are tightened to the coal nozzle tip after fixing the lifting apparatus. While lifting the coal nozzle with the lifting apparatus, the center of gravity falls at the center of the coal nozzle. All the degrees of freedom are arrested by this apparatus after positioning. Coal nozzle is directly inserted into the super critical wind box compartment and positioned and fixed in the compartment. Fasteners (05) are loosened after positioning the coal nozzle in the super critical windbox and the lifting apparatus is removed from the coal nozzle.
The lifting apparatus is inserted inside the coal nozzle tip (06) from the other side and rested on the nozzle tips to tighten the fasteners (05). The lifting apparatus is positioned inside the coal nozzle which is shown in figure - 2.
After using the invented apparatus, the cycle time for lifting and positioning the coal nozzle inside the windbox compartment has been reduced from 30minutes to 15 minutes.

WE CLAIM
1. An apparatus for lifting and positioning coal nozzles inside the coal compartments in supercritical windboxes for fuel firing in power plants; comprising:
a first plate (01) disposed horizontally and at two ends welded to a plurality of plates (02) perpendicularly the first plate (01) is welded at the center to a vertically disposed second plate (03); a plurality of fasteners (05) provided on said plurality of vertical plates (02), a third plate (04) welded at the bottom of the first plate (01), wherein the plurality of plates (02) and the third plate (03) are provided to position the coal nozzle during lifting.
2. The apparatus as claimed in claim 1, wherein the third plate (04) is provided at the bottom, to give support to the first plate (01).

3 The apparatus as claimed in claim 1, wherein the plurality of fasteners (05)
are provided to lock the coal nozzle tip during lifting and prevent horizontal and vertical movements.