FIELD OF THE INVENTION
The present invention relates to a method of fit up of cone assembly in a circular
pipe. More particularly, the invention relates to a method for fixing a cone
assembly concentrically inside a pipe of separator vessel of once through
Supercritical boilers.
BACKGROUND OF THE INVENTION
In the known Once through Supercritical boilers, the separator which replaces
the drum in subcritical boilers is the most important component. The separator
is used to separate steam from water-steam mixture subcritical operation mode
of the Once through Supercritical boilers. The outside diameter of the separator
is generally about 812.4 mm having a thickness of approximately 90 mm and the
material normally used is P91 alloy steel. In order to realize steam-water
separation and uniform distribution, a cone assembly is normally fixed inside the
separator, at a distance about 965 mm from one end of the separator. During
fixing up the cone assembly if there is any variation in concentricity, the
performance of the boiler is severely affected. On the other hand, it is quite
difficult to locate the cone assembly, weighing about 146 kg at a distance 965
mm preciously from one end of the separator having only 633 mm inner
diameter.

Throughout the fixing-up operation of the cone assembly, the stiffener plates
are used with tack weld on the cone assembly for maintaining the concentricity j
and avoiding imbalance. After fit up, the stiffener plates are removed by the
operators through grinding by entering inside the pipe from the opposite end,
which is unsafe. During the fit-up, the edges of the separator pipe gets damaged
by the chain used for lifting and pushing inside the pipe. Hence, there is a need |
for a new method and an apparatus to fix-up the Cone assembly inside the
Separator pipe.
j
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to propose a method for fixing a
cone assembly concentrically inside a pipe of separator vessel of once through j
Supercritical boilers.
A further object of the invention is to propose a method for fixing a cone
assembly concentrically inside a pipe of separator vessel of once through
Supercritical boilers which allows the cone assembly to be fixed-up inside the
separator in a predetermined position more precisely for welding.
SUMMARY OF THE INVENTION
Accordingly, there is provided a method for fixing a cone assembly concentrically
inside a pipe of separator vessel of once through Supercritical boilers. The
apparatus in which the fixing method is performed, having a fixed arm and a

removable arm with flange connected to a screw jack assembly. The removable
arm is fixed to a stopper plate and a clamping screw to fit-up the cone assembly
over the removable arm. The removable arm is connected to the fixed arm. The
fixed arm is connected to a screw jack of the screw jack assembly which can be
rotated for the upward and downward motion of the fixed arm thereby, the
height can be adjusted.
The bottom of the screw jack is welded with a base plate which is having main
rollers at the bottom. A supporting roller is connected to the bottom of the screw
jack assembly. The base plate is provided with a pushing handle and a pulling
handle for to and fro motion.
Now, the cone assembly is fixed in between the clamping screw and the stopper
plates. The removable arm can be lifted vertically by rotating the screw jack in
such a way that this can be inserted into the separator.
The concentricity of the fit-up is checked and deviation if any is connected
without damaging the separator pipe edge preparation.
The pushing handle is simply pushed for inserting the cone assembly inside the
pipe of the separator at the pre determined position. Finally, the tack weld is
made between the cone assembly and the separator. After loosening the
Clamping screw in the removable arm, the pulling handle is used to withdraw the
apparatus.

Now, the cone assembly can be fixed without engaging any crane, and also
substantial man hour can be saved.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 shows a separator cone which is to be fitted up on the separator pipe of
the separator vessel.
Figure 2 shows the cone assembly in the separator vessel.
Figure 3 shows an apparatus of the invention with the cone assembly.
DETAILED DESCRIPTION OF THE INVENTION
Referring to figure 1, the cone assembly shown (12) for an exemplary purpose is
having an outside diameter of approximately 629 mm with a height of 475 mm
and weighing about 146 kg.
Referring to figure 2, the cone assembly (12) of figure 1 is shown with a
separator pipe assembly.
Referring to figure 3, the cone assembly (12) is fixed in between the clamping
screw (3) and stopper plate (2). The Screw jack (6) is rotated so that the fixed
arm (5) can be moved upward to a vertical distance where the Centre of the
separator pipe (not shown) coincides the Centre of the removable arm (4).

The pushing handle (7) is pushed towards the separator pipe to a pre-
determined distance which according to the exemplary cone assembly and the
separator, is about 965.2 mm from the pipe end. Now, tack weld is carried out in
the cone assembly (12). The Pulling handle (8) is used to withdraw the
apparatus from the separator pipe with the help of a plurality of main rollers (10)
and supporting rollers (11). The base plate (9) is used to place the screw jack
(6) in the vertical direction. .

WE CLAIM :
1. A method for fixing a cone assembly concentrically inside a pipe of
separator vessel of once through Supercritical boilers, comprising the
steps of :
providing a fixing apparatus;
fixing the cone assembly (12) between a clamping screw (3) and a
stopper plate (2) in a removable arm (4) of the apparatus which is
attached to a fixed arm (5), through a flanged connection (1) wherein
the fixed arm (5) is attached to a screw jack (6) assembly, for up and
down movements for inserting the cone assembly inside the separator
pipe, wherein a horizontal movement of the cone assembly is realized
through operating a pushing handle (7) and a pulling handle (8)
connected to a base plate (9) over a plurality of main rollers (10)
including supporting rollers (11) attached to the bottom of the screw
jack (6), thereby locating the cone assembly for fit-up.

2. The method as claimed in claim 1, wherein the cone assembly (12) is
fitted-up inside the separator pipe (13) at a predetermined position of the
once through supercritical boilers for steam water separation.

ABSTRACT

The invention relates to a method for fixing a cone assembly concentrically
inside a pipe of separator vessel of once through Supercritical boilers, comprising
the steps of providing a fixing apparatus; fixing the cone assembly (12) between
a clamping screw (3) and a stopper plate (2) in a removable arm (4) of the
apparatus which is attached to a fixed arm (5), through a flanged connection (1)
wherein the fixed arm (5) is attached to a screw jack (6) assembly, for up and
down movements for inserting the cone assembly inside the separator pipe,
wherein a horizontal movement of the cone assembly is realized through
operating a pushing handle (7) and a pulling handle (8) connected to a base
plate (9) over a plurality of main rollers (10) including supporting rollers (11)
attached to the bottom of the screw jack (6), thereby locating the cone assembly
for fit-up.