Rotary, regenerative heat exchanger having floating sealing rings

A rotary regenerative heat exchanger comprising an inner cylindrical post shell, an outer cylindrical shell interconnected with said inner shell by a radial partition wall, and rigid sealing rings at opposite ends of the outer shell. The outer or the inner end portion of each radial partition wall is slidingly adopted in an axial slot in the outer or inner shell, respectively, and the outer end portions of each partition wall are also slidingly engaging said sealing ring in a radial direction in order to isolate the floating sealing rings from the thermal deformation of the load carrying structure.

BACKGROUND OF THE INVENTION 
This invention relates to rotary regenerative heat exchangers of the type 
comprising two main parts relatively rotatable with respect to each other 
about a common central axis, a first of said main parts constituting a 
regenerator body comprising an inner cylindrical post shell and an outer 
cylindrical shell interconnected with said inner shell by a plurality of 
radial partition walls forming a plurality of open-ended sectorial 
compartments containing a regenerative heat transferring mass providing 
passages for flow of fluid media therethrough from and to the ends of the 
regenerative body, and the second of said main parts constituting a duct 
part providing ducts having inlets and outlets for flow of heat emitting 
and heat absorbing fluid media to and from the opposite ends of said 
regenerator body, at least one of the ends of said outer shell being 
provided with a sealing ring positioned in the clearance between said main 
parts. 
In rotary regenerative heat exchange apparatus of a common type referred 
to, a cylindrical rotor carrying the compartments of heat absorbent 
material is first exposed to a flow of heating fluid such as hot exhaust 
gas that is directed through a limited portion of the rotor. Upon rotating 
the rotor about its axis, the heated heat absorbent material is positioned 
in the path of a relatively cool fluid to be heated such as air, whereby 
the heat of the gas may be transferred thereto. The rotor is surrounded by 
a housing including a stationary duct part that simultaneously directs the 
heat emitting and heat absorbing fluids through spaced compartments of the 
rotor. 
The rotor is subjected to a substantial temperature gradient whereby the 
structural components thereof warp and distort to the extent that 
effective sealing between the rotor and enclosing housing is difficult if 
not impossible to obtain. 
It is therefore a primary object of this invention to provide a rotary 
regenerative heat exchanger whose sealing surfaces are not subject to the 
usual excesses of thermal distortion. 
Due to a non-uniform temperature distribution, and especially under certain 
conditions, such as overload, the thermal deformation of the structural 
components, as the radial partition walls, often results in fracture of 
weld joints and other damage involving deformation of the sealing 
surfaces. 
Therefore it is also an object of this invention to provide a rotor or 
regenerator body in which the weld joints are relieved from dangerous 
stresses. 
A known regenerative heat exchanger having a cylindrical rotor carrying 
heat transfer material and having rigid sealing rings is shown in U.S. 
Pat. No. 2,981,521, and a similar heat exchanger is shown in British Pat. 
No. 1,376,122. In both cases the sealing rings are fixedly attached to 
rigid radial or diametric partition walls or webs the thermal expansion of 
which in the radial direction gives rise to deformation of the sealing 
rings. 
Another known rotary regenerative heat exchanger is shown in British patent 
specification 1,046,16 in which the heavy heat transferring mass is 
supported by rigid radial diaphragms extending radially outward from the 
post shell to the concentric rotor shell forming a part of the sealing 
means and subjected to radial deformation forces. 
SUMMARY OF THE INVENTION 
The present invention provides a regenerator body structure that insolates 
the supporting structure from the sealing structure so that thermal 
deformation of the support structure does not give rise to any deformation 
of the rigid sealing ring. This has been achieved according to the 
invention in that the outer or the inner end of each radial partition wall 
is slidingly adopted in an axial slot in the outer or inner shell, 
respectively, the remaining end of each partition wall being fixedly 
attached to the corresponding outer or inner shell respectively, at least 
every second of the partition walls being of the type having its outer end 
slidingly connected to the outer shell, in addition to which said 
partition walls are also slidingly engaging said sealing ring in radial 
direction. 
Although it is obvious that the invention is applicable to heat exchangers 
having a rotating component carrying the regenerative mass and a 
stationary component comprising fluid ducts, as well as to heat exchangers 
having a stationary component carrying the regenerative mass and a 
rotating component comprising fluid ducts, the following specification 
describes by way of example the first-mentioned kind of heat exchangers 
for the sake of simplicity.

DETAILED DESCRIPTION 
The rotary regenerative heat exchanger shown in FIGS. 1 and 2 comprises a 
rotor 1a having an inner cylindrical port shell 2 and an outer cylindrical 
shell 3 interconnected with said inner shell by a plurality of radial 
partition walls 4 forming a plurality of open-ended sectorial compartments 
containing baskets of heat transferring metal plates (not shown). 
The partition walls 4 have inner ends welded to the rotor post and outer 
ends slidingly journalled in axial slots 6 in the outer shell 3 and in 
radial slots 7 of two rigid sealing rings 8, 9 sealingly connected to the 
spaced ends of the wall segments of the outer shell 3. The upper sealing 
ring 8 is welded to said wall segments and the lower sealing ring 9 is 
suspended by means of links 10 secured to the upper sealing ring 8. The 
lower sealing ring 9 is provided with a circular groove 11 receiving the 
bottom ends of the wall segments 3. 
Thus, the outer ends of the radial partition walls 4 are displaceable 
radially in the axial slots 6 of the outer shell 3 and in the radial slots 
7 of the sealing rings 8, 9. The sealing rings are positioned concentric 
to the inner shell 2 and outer shell 3 by the partition walls 4 which 
together with the slots 7 do not permit displacement of the sealing rings 
8, 9 perpendicular to the radial partition walls 4 and the lower sealing 
ring 9 is suspended by means of links 10 secured to the upper sealing ring 
8. The lower sealing ring 9 is provided with a circular groove 11 
receiving the bottom ends of the wall segments 3. 
Thus, the outer ends of the radial partition walls 4 are displaceable 
radially in the axial slots 6 of the outer shell 3 and the radial slots 7 
of the sealing rings 8, 9. The sealing rings are positioned concentric to 
the inner shell 2 and outer shell 3 by the partition walls 4 which 
together with the slots 7 do not permit displacement of the sealing rings 
8, 9 perpendicular to the radial partition walls 4. 
The heat exchanger is provided with the usual sector plates 12 (FIGS. 3 and 
4) at opposite ends of the rotor 1 and the radial partition walls are 
provided with flexible radial sealing members 13. 
Under certain conditions a "turn-down" of the radial partition walls 4 
takes place due to thermal deformation of the rotor structure. The sector 
plates 12 and radial sealing members 13 are also turned down by an angle, 
as shown in FIG. 3, but the rigid sealing rings 8, 9 and the outer shell 
segments 3 are not deformed but are only displaced a corresponding 
distance downwards. 
In FIGS. 4 and 5 at least the sealing ring 8 is connected to the rotor post 
by a centering device comprising a series of radially extending flexible 
wire-spokes 14. The spokes 14 may be used during the construction of the 
heat exchanger and may be removed after that. 
FIGS. 6 and 7 show another embodiment of the invention having an integral 
outer shell 3 in which interior axial channel members 17 are used to 
substitute for the outer shell segments 3 and slots 6. Every second 
partition wall 4 is welded to the inner post shell 2, each having its 
outer end portion slidingly received in one of the channel members 17 
which is welded to the outer shell 3. The remaining partition walls 4 are 
welded to the outer shell 3 each having its inner end portion slidingly 
received in a corresponding axial slot 18 in the rotor post shell 2. In 
this case the upper sealing ring 8 is floatingly supported by the outer 
shell 3 guided only by exterior radial wall portions 4' welded on the 
outer shell 3 and forming extensions of the partition walls 4. It is also 
possible to arrange the partition walls 4 such that all partition walls 4 
are fixedly attached, for instance welded, to the rotor post 2, and all 
other ends of the partition walls 4 are slidingly received in channel 
members 17. 
It is to be understood that while several embodiments herein described and 
illustrated by way of example vary materially in their specific structural 
arrangements and modes of operation, all are embraced within the scope of 
the present invention which is to be construed as embracing all structures 
falling within the scope of the appended claims.