FIELD OF THE INVENTION
The present invention generally relates to a fluidized bed heat exchanger. In
particular the invention relates to a device for supporting heat exchanger tubes
including various sections of the tube relative to each other within the heat
exchanger. More particularly, the invention relates to a device for supporting
steam coils of fluidized bed heat exchanger by means of multi-loop hangers
without a weld between them.
BACKGROUND OF THE INVENTION
The use of fluidized beds has been recognized as an attractive means of
generating heat in a heat exchanger such as a boiler, a combustor, a gasifier etc.
In these arrangements, air is passed through a bed of particulate material which
normally consists of a mixture of inert material and a fossil fuel such as coal to
fluidize the bed and to promote the combustion of the fuel. When the heat
produced by the fluidized bed is utilized to convert water to steam such as in a
steam generator, for example, the fluidized bed system offers an attractive
combination of high heat release, improved heat transfer to surfaces within the
bed and compact size. In these types of arrangements, pluralities of heat
exchange tubes are usually connected to external headers. The tubes are
normally supported in an elevated position according to US Patent No. 4270599.

US Patent Nos. 4619315 and 4637455 describe a hot (not working fluid cooled)
support system for an in-bed heat exchanger that transmits the load on the heat
exchanger to the tube support bracket hence to a support member there
beneath and be readily replaceable without pressure part alteration.
US Patent No. 2876975 teaches minimizing the deflection and stresses under
operating conditions, wherein a flexibly mounted sectionalized tube-supporting
plate has been devised, which will further provide a substantial support for the
tubes under the weight of the un-fluidized material. Because, at high
temperatures, considerable relative movement between the hot tube sheet and
the adjacent tube supporting plate may occur as the operating temperature
changes, due to differential thermal expansion caused by variations in size and
temperature between the hot tube sheet and the adjacent tube supporting plate.
Such relative movement results in deflection of the tubes and may produce
deflection in excess of the elastic limits of the tubes or stresses in excess of the
strength of the tubes, particularly at the juncture to the hot tube sheet.
OBJECTS OF THE INVENTION
It is therefore, an object of the present invention to propose a device to support
steam tubes of fluidized bed heat exchanger formed without a weld between the
steam tubes and hangers.

Another object of the invention is to propose a device to support steam tubes of
fluidized bed heat exchanger formed without a weld between the steam tubes
and hangers which limits the stress in the device when the structural loads and
thermal loads are applied to the device.
A still another object of the present invention is to propose a device to support
steam tubes of fluidized bed heat exchanger formed without a weld between the
steam tubes and hangers which simplifies method of supporting the coils
including easing out the process of attaching and removing and replacing the
device.
Yet another object of this invention is to propose a device to support steam
tubes of fluidized bed heat exchanger formed without a weld between the steam
tubes and hangers which provides the "in plane stability of the device".
A further object of this invention is to propose a device to support steam tubes
of fluidized bed heat exchanger formed without a weld between the steam tubes
and hangers which eliminates deployment of fastening members.

A still further object of this invention is to propose a device to support steam
tubes of fluidized bed heat exchanger formed without a weld between the steam
tubes and hangers which simplifies the process of manufacturing looping
arrangement.
Yet further object of this invention is to propose a device to support steam tubes
of fluidized bed heat exchanger formed without a weld between the. steam tubes
and hangers which eliminates welding of supporting hangers to steam tubes.
SUMMARY OF THE INVENTION
Accordingly, there is provided a device to support steam tubes of fluidized bed
heat exchanger formed without a weld between the steam tubes and hangers .
According to the invention, the device supports the steam coils in the fluidized
bed heat exchanger in which the various sections of the heat exchange tubes are
supported in a manner to prevent sagging of the sections.
The supporting coils and the steam tubes are made of same material for
manufacturing considerations.

The supporting assembly is formed of a plurality of tubes through which a
cooling fluid is passed to lower the temperature of the assembly.
In accordance with the present invention, a cooled support system for supporting
a tubular in-bed heat exchanger that transmits the load thereon to the tube
support is disclosed. The cooled support system is comprised of a plurality of
multi-loop system.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The above brief description, as well as further objects, features and advantages,
of the present invention will be more fully appreciated by reference to the
following detailed description of the presently but nonetheless illustrative
embodiment in accordance with the present invention, when taken in connection
with the accompanying drawings.
These features of the present invention will become more apparent upon
reference to the drawings, wherein :

Figure 1 is an isometric view of the device of the present invention.
Figure 2 is a front view of the device of Figure 1.
Figure 3 is a top view of the device of Figure 1.
Figure 4 is a side view of the device of Figure 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE
INVENTION
Referring to Figure 1 of the drawings, the present invention will be described in
connection with a fluidized bed boiler.
The advantages of the present invention may be fully appreciated by explaining
the arrangement.
In the preferred embodiment, the .device is made of a single unit by
implementing a bending process in a die. The device consists of a supporting
member 1 and a plurality of steam coils 2, 3, 4, 5, 6 and 7, the supporting

member 1 being the main load-carrying member of the embodiment is made of
multi-loops; the loops are formed of a plurality of members 12, 13 and 14, each
loop attached to the previous one is having identical configuration so that the
steam tubes passes through these loops; at both ends of the multi-loop, two
vertical members 11 and 16 are connected to produce a full proof support device
for the steam coils wherein the members are made of similar material so that the
differential thermal expansion is reduced as well as the stress, and wherein no
welding is provided for metal to metal contact. This is also another advantage of
the support device to have no dissimilar weld of the metal.
Thus, the present invention provides a novel device for supporting the coil
structures. Those skilled in the art will recognize that the present invention may
be readily adapted to accommodate a variety of different diameter and weight of
the structures.
The material is chosen such that the present invention can be suited from
thermal expansion point of view.

ADVANTAGES OF THE INVENTION
The device prevents structural failure in fluidized bed heat exchanger. Two
supporting members with thermal contact allow thermal movement of the
device.
The vertical members of the device is made in such a method that maximum
load transfer will be through this connecting member only.
The device further supports the buoyancy effect of fluidized bed including the
dynamic behaviour of the boiler. The device reduces thermal stresses due
elimination of dissimilar metals and welding. Further, manufacturing efforts for
the device is reduced due to elimination of welds.

WE CLAIM :
1. A device to support steam tubes of fluidized bed heat exchanger formed
without a weld between the steam tubes and hangers comprising :
a supporting member 1 and a plurality of steam coils 2, 3, 4, 5, 6 and 7, the
supporting member 1 being the main load-carrying member of the embodiment
is made of multi-loops; the loops are formed of a plurality of members 12, 13
and 14, each loop attached to the previous one is having identical configuration
so that the steam tubes passes through these loops; at both ends of the multi-
loop, two vertical members 11 and 16 are connected to produce a full proof
support device for the steam coils wherein the members are made of similar
material so that the differential thermal expansion is reduced as well as the
stress, and wherein no welding is provided for metal to metal contact. This is
also another advantage of the support device to have no dissimilar weld of the
metal.

ABSTRACT

The invention relates to support steam tubes of fluidized bed heat exchanger
formed without a weld between the steam tubes and hangers comprising a
supporting member 1 and a plurality of steam coils 2, 3, 4, 5, 6 and 7, the
supporting member 1 being the main load-carrying member of the embodiment '
is made of multi-loops; the loops are formed of a plurality of members 12, 13
and 14, each loop attached to the previous one is having identical configuration
so that the steam tubes passes through these loops; at both ends of the multi-
loop, two vertical members 11 and 16 are connected to produce a full proof
support device for the steam coils wherein the members are made of similar
material so that the differential thermal expansion is reduced as well as the
stress, and wherein no welding is provided for metal to metal contact. This is also
another advantage of the support device to have no dissimilar weld of the metal.