Note: Descriptions are shown in the official language in which they were submitted.
~097099
This invention relates to chimneys having an outer
co]umn, usually of reinforced concrete and an inner liner. In
particular it relates to the provision of metal hreeching
entries to be used with inner brick liners.
The present requirements for pollution control often
require flue gas scrubbing techniques. Any unprotecte-l steel
chimney liners may be subject to corrosion and therefore, coated
steel liners are required. To avoid the need for such coated
liners acid brick constru;ction has been employed for tall
1~ chimney linings. However, the design and construction of brick
linings is not too satisfactory, especially where there are
large breeching openings. Severe cracking and structural
problems are caused by the discontinuities occasioned by the
presence of the breeching openings and stresses in the brick
piers due to non-uniform thermal gradients. In addition the
differential temperature effects cause large lateral
displacements at the top of the chimney, which are difficult to
- restrain because of the high forces involved.
The present invention overcomes the problems of the
-~ 20 brick liners while retaining the advantages thereo by combinin~
~ the brick liner with an insulated steel breeching entry and
liner. As a result, rational steel construction design can be
used instead of largely empirical brickwork design in the
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breeching region, lateral deflection at the top of the brick
lining caused by non-uniform thermal expansion is reduced, high
compressive stresses at the side of the breech openings are
eliminated, a smaller chimney foundation is required sincc ~le
overall chimney is lighter in weight, and useable space is made
available at the base of the chimney.
The present invention suspends a steel liner and
breeching entry at the lower part of the brick liner by
fasteners which are connected to a circular ring beam supported
on the chimney column, and by constant load spring hangers
located at the top of the breeching duct where it passes through
the concrete c!himney column. The purpose of these spring
hangers is to load the ring beam as uniformly as possible.
Since most of the gas temperature imbalance exists in the
vicinity of the suspended breeching, the lateral deflections at
the top of the brick lining are greatly reduced. The portion of
; the liner in the vicinity of the breeching opening is in
tension, eliminating high compressive stresses thereat. An
expansion joint may be included to give additional thermal
~ 20 expansion capacity to the liner.
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In this parent application the invention comprehends
an improved liner for a chimney having an outer column ~ith an
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exterior and inner surface. The inner lining has a lower end,
and breeching means joined to the lining. A breeching member
comprised of an upright tubular element generally in line with
the lining, and at least one lateral tubular element is
provided. The lateral element extends through the outer
chimney column to form a breeching entry. Sus~ensioll means
coacting with the outer chimney column and the upright tubular
element are provided for suspending the breeching member within
the chimney at the lower end of the lining. Further a constant
loading hanger means for suspending the lateral tubular element
from the outer chimney column adjacent the breeching entry is
also provided. Further the breeching member may be insulated
and may have at least two lateral tubular elements disposed
generally horizontally or at a slight obtuse angle io the
tubular elements. Additionally the breeching member can be
symmetrical or substantially evenly balanced about its vertical
axis.
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In the accompanying drawing:
- Figure 1 is a cross sectional view of the lower
20~ portion of the chimney.
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Figure 2 is a cross sectional view similar to
Figure 1 but showing a modification of the breeching portion
only.
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109709~
Figure 3 is a cross sectional view of a portion oE the
upper part of the liner showing a modification incorporating an
expansion section.
Figure 4 shows in section a modification of the joint
portion.
i The present invention, as seen from Figure 1, includes
a conventional chimney column 1, generally of reinforced
concrete, having at its lower portion a breeching opening 2.
Above opening 2 is a reinforced concrete circular ring beam or
base 3 which is seated on ~ circular corbel 4 as shown in the
figure. A chimney liner 5 of acid brick construction is built
on the ring beam or base 3, separated from chimney column 1 by
space 6 which may be pressurized or kept at ambient conditions,
as desired.
Fastened to circular ring beam 3 is a steel liner
and breeching entry 7 consisting of a vertical portion 8 and
~ lateral breeching duct element 9 which extends through
breeching opening 2 in chimney column 1. The upper encl of 8
is flared out to form a collar as shown at 10, and its diameter
is somewhat less than that of the inner diameter of the circular
ring beam and seats over portion 19 of the ring beam.
From the figure it will be seen that the upper end of 10 is
slightly below the top of the circular ring beam. A ring
plate 12 is fastened near the upper portion of 8, as by
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welding, and is attached to anchor bolts 13, cast in ring
beam 3. The bolts pass through corresponding holes in ring
plate 1~, which is fastened by nuts and washers 14. The
diameters of the holes are made sufficiently larger than the
bolt diameters and the nuts are so tightened as to permit a
degree of sliding movement between ring plate 12 and the
underside of ring beàm 3 to permit radial thermal expansion.
Lead or similar flashing 15 overlap the top of the flared
portion 10, the upper part of the circular ring beam and has
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its end embedded in the inner wall of the ch~mney column as
shown in the figure, It will be noted that the brick liner
is laid on top of the flashing, It is apparent that some
motion of the upper portion of 8 relative to ring beam 3 and
brick liner 5 may take place and thus accolluno(late tl~erlllal
strains,
Lateral portion 9 is suspended at location 16 from
the concrete chimney column 1 at the upper part of the bre-
eching opening 2 by constant load spring hangers 17 (only one
shown~, The hangers are attached to 1 and 9 by means (not
shown) which permit pivoting motion, such as ~ clevis or the
like, whereby motion of the steel liner 7 due to temperature
changes may be accom~odated and reduce ~ccentric loads on the
circular beam caused by the weight of the breeching,
The outer portion of 7 is coated with insulation
such as fiberglass, mineral wcol or the l~ke shown as 18,
Similarly, the space between the inner portion of ring beam
3, ring plate 13 and the upper part of 8 is filled with
insulation,
:~ 20 The liner shown is generally constructed of carbon
: steel, but other steels may be employed, For strength and
ri$idity it is externally stiffened as by having angles or
:: other structural shapes Cnot shown~ welded thereon, Instead
. of steel, other material may be employed to meet special re-
: quirements, such as plastics or other materials which are
corrosion resistant and can withstand the other conditions of
operation,
While the lateral portion 9 is shown as being at a
slight angle from the horizontal, this may be varied to from
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substantially horizontal to a steeper incline. Altllough
Figure 1 shows a single breeching entry, more than one entry
may be provided. This is illustrated by Figure 2, where two
opposing lateral breeching duct element 9 and 9' are shown,
Duct 9~ is shown connected to column 1 by a spring hanger 17'
which is identical with element 17, While this ~igure shows
two breeching entries, it should be obvious to one skilled
in the art that additional entries may be provided as needed,
No eccentric loading is placed on the circular ring beam,
when the liner and beaching entries form a unit which is
symmetrical or substantially evenly balanced about its
vertical axis,
In these cases the spring hangers are not
required, but may be employed, if desîred, to reduce the
load on the ring beam,
: When additional thermal expansion capacity is
desired this can be readily accomplished by introducing an
expansion joint and spring hangers in the vertical portion o
steel liner 8, near the underside of ring beam 3. This modi-
fication is shown in Figure 3 wherein expansion joint ~0 is
provided at the upper portion of steel liner 8, below ring
plate 12, Joint 20 consists of a plurality of shaped cor~
rugations which taken together form a bellows, Arm 21 is
rigidly attached to 8 below the lowermost corrugation and
extends laterally therefrom~ Expansible hangers indicated
generally by reference numeral 22 connects arm 21 to circular .
ring beam 3~ as will be described in greater detail herein-
after, An upper connecting bracket 23 is rigidly attached
to the underside of beam 3, as by an anchor bolt,
~097099
A clevis 24 having a dependent portion 25 is pivot-
al:Ly attached to bracket 23 by a pin or bolt, and has- an
internally threaded bore in the dependent portion. Arm 21 has
pivotally attached thereto at its outer end an enclosed
spring expansible means 26. The upper portion of 26 has an
internally threaded portion. Rod 27 having threaded ends 28
and 29 are screwed into 26 and 25 and secured in plac~ ~
nuts 30 and 31. The hangers are sized and spaced so that the
dead load of the suspended liner compresses the springs to
their median position. While spring means are shown, other
expansible hanger means may be employed, e.g. hydraulic or
pneumatic. Similarly other types of expansion joints can be
used such as viton-teflon, neoprene, etc.
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This method of suspension conserves the capacity of
; joint for expansion and rotation. The suspended portion of
the liner can articulate in any direction, absorb vibration
~ and take up differential expansion. In view of this arti-
- cuIating capacity, the joint between the brick and steel
portion can be rigid. This is shown in Figure 4 where the
20~ flared end 10' is imbedded in the brick liner.
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