Improvements in and relating to Bosh Jackets for Blast Furnaces.
Year: 1891

page_text: Date of Application, 19th May, 1891-Accepted 27th June, 1891
COMPLETE SPECIFICATION.
Improvements in and relating to Bosh Jackets for Blast
Furnaces.
1, MORRIS RUSSEL HUNT, a citizen of the United States of America, residing
at No. 7, Fifield Place, in the City of Ashland, County of Ashland and State of
Wisconsin, United States of America, Manager of Blast Furnace, do hereby
declare the nature of this invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
the same.
My invention has relation to improvements in bosh jackets for blast furnaces.
Heretofore in devices of this character, operators have found it necessary to
provide some device to overcome the destructive action of the intense heat and
friction upon the brick-work of the bosh. If no cooling is used in the bosh, from
one-half to three-fourths of the original masonry is cut away in a few weeks, except
at tuyere breasts or coolers, which are held intact by the cooling effect of water in
The increased diameter of the bosh above such water cooled breasts
forms a ledge or projection at the latter. This prevents the furnace from working
regularly (causing slipping) and the fuel consumption is materially increased. To
hold the original bosh lines intact, various devices are used, one of the most popular
being bosh plates made of iron or bronze. These plates are made in sections of
six or eight to a circle and built two or more feet apart. Years of experience with
these plates has proved them not satisfactory, as the brick work is only kept intact
a few inches from the plate, and thereby an increased number of shells are formed,
causing very unsatisfactory working of the furnace. If these plates are made of
iron speedy corrosion sets in, the pipe chokes with sediment or leaves, and the
water must be turned off, leaving the plate dry in the furnace, as it
impossible to remove it for the purpose of replacing.
next to
Other devices used for the same purposes are bronze or iron bosh boxes made
circular or square in shape, and formed so as to be removable when necessary.
These boxes are placed apart horizontally about fifteen inches, vertically about
twenty-four inches. With these devices, also, more or less cutting out of the brick
work between the boxes takes place, increasing fuel consumption and shortening the
life of furnace. Both bosh plates and bosh boxes have a tendency to weaken the
walls more or less. Various devices are used for cooling the bosh from the outside.
Series of pipes running horizontally or vertically, and held to the brick work by
bands or jackets have been used. Experience has also proven that these means
are a failure for the purpose intended, as the cooling surface of the pipe is so
small as to cause the masonry to frequently break through between the pipes.
To replace a leaky or defective pipe when placed behind the jacket is a very
difficult matter. Buckets. or pockets secured to furnace shells are occasionally
used, and also means for spraying the shell with water. Unsatisfactory results,
however, have been obtained with both. Spraying the masonry of the bosh is
sometimes adopted but that method is objectionable owing to the speedy destruction
of brick, caused by moisture on outside and heat on inside.
It is the object of my invention to avoid the disadvantages pointed out and
incident to the devices now ordinarily employed, and I propose to effectually cool
the bosh from the outside, and so arrange the structure as to add strength to tho
furnace and also increase its life.
In the accompanying drawing-
Figure 1 is an elevation partly in section of a furnace provided with my
invention.
Figure 2 is a detail view, partly in section, of one of the bosh plates, showing the
interior arrangement of the tortuous passages;

page_text: Figure 3 is a vertical section on the line, Figure 2.
Figure 4 is a plan view of the connected plates showing a luting placed between
the meeting edges;
Figure 5 is a horizontal section;
Figure 6 is an end view of one of the plates; and
Figures 7, 8 and 9, are views of modified forms of the plates.
From
Like letters of reference refer to like parts throughout the several views.
A single plate of bosh jacket is represented by Figure 2 of the drawing.
this figure it will be seen that the plate consists of a hollow casting two inches
thick, more or less, and provided with a series of water ways, A, formed by webs
or partitions, B, arranged intermediate the front and back portions of the plate,
running horizontally, as in Figure 1, vertically as shown in Figure 8, or both
horizontally and vertically, as shown in Figure 7. The object of these webs is
two-fold, eiz. to produce circulation of water, and afford strength to the plate,
thereby preventing it from collapsing. It will be noticed that these webs or
partitions are connected to the jacket at one end only, and that the ends so
'connected alternate, that is to say, the lower partition, as shown in Figure 2, is
connected at the right hand end, while the partition next above is connected on the
left hand side, and so on throughout the series. The jackets and tortuous passages,
it will be understood, are cast in one piece, each passage, A., being formed by a
core, the ends of which are reduced and pass through the usual framing, and are
supported therein. The holes left by the ends of the core in the framing, and
shown in Figures 2, 7 and 8, are then stopped up in any desirable manner.
The plates or sections are formed on opposite ends with projections, C, C¹. One
plate of the series it will be observed, has projections on both ends, near its inner
side, and the plates adjoining projections near their outer side, or each plate may
have an inside projection on one end and an outside projection on the other.
The letters, D, D1, indicate similar projections on the top and bottom of the
plate. In place of the projections just described, V-joints, as shown in Figure 9,
may be employed on all sides, if so desired.
I have indicated the outer and inner walls forming the plate, by the letters, E,
and E, respectively, the former having cast upon its outer surface a series of
inclined lugs, F. These lugs are designed to receive annular straps or bands; F¹,
which serve to hold the series of plates in each circle together. These bands are,
of course, of greater circumference than the furnace, and are held to their position
by means of the inclination of the lugs. For the purpose of greater security, and
to facilitate the ready removal of the plates, however, I interpose between the lugs
*and the inner sides of the bands, wedges or keys, F.
The inner wall, E', of the section or jacket is provided upon the side adjacent to
the masonry with ribs, G, which contact with and engage the masonry.
It is well
known that in a very short time after the furnace is in blast, the brick work in
numerous places is burnt and carried away by the friction of descending stock.
These ribs, however, serve the function of holding the masonry intact, notwith-
standing incrustation.
Each plate or section of jacket is provided with a suitable inlet, designated by
the letter, H, and an outlet designated by the letter, 1. The positions of the
openings of course vary with the character of the jacket used. When a plate is
used constructed as shown in Figure 2, the inlet is located at the lower right hand
corner, while the outlet is located at the upper left-hand corner. In case the
constructions shown in Figures 7 and 8 are employed, the inlets and outlets are
both located at the lower end, at opposite corners. The inlet and outlet openings
will of course be provided with suitable tubing or piping, not shown, by means of
which the water is introduced into each section or plate, and after circulation
withdrawn therefrom.
The entire jacket can be placed on the outside of the brick work of the furnace
when completed, or the plates can be erected and firmly banded and keyed and the
masonry built inside of the same. The object of the interlocking projec

page_text: tions C, and C, and D, D', is to make the jacket practically continuous throughout,
horizontally and vertically, and as strong as a riveted jacket of three-quarter of an
inch steel plate.
By a luting, J, consisting of fire clay and asbestos, placed on the face of these
projections a positively air and gas tight jacket is secured. This latter prevents
the gas from coming through any one of the joints, and air from getting inside of
the jacket, and prevents the furnace from burning through at any point. This
fact, coupled with the safe and effectual cooling obtained, makes this jacket a very
desirable one.
It is furthermore apparent by the employinent of my invention a very rapid
circulation may be obtained throughout each plate and entire jacket by simply
decreasing the width of the water channels, A. Any section of the bosh three feet
long by two feet wide (being average size of plate) can be cooled more or less by
regulating the water accordingly.
By constructing the bands, F', which surround the plate, of such circumference
as to engage the lugs, F, the keys, F2, herein before referred to, may be readily
removed from any one or two plates, and any number of the plates can be speedily
removed should occasion require, and that without affecting the support afforded
by any band, no portion of the entire bosh being weakened, except the place where
one or two plates are taken out. That this arrangement admits of the removal of
the destroyed plate, and the replacing of it by a new one in a very short time, is
apparent. Ability to detect any leaky place is self evident. The difficulty of
surely detecting leaky devices built into brick-work has prevented many furnace
managers from using them.
By the use of my bosh jacket masonry of minimum thickness only is required,
thereby reducing the cost accordingly, while at the same time, the maximum
diameter of bosh can be increased, with corresponding increase of product. By the
interlocking of each plate and the banding of each circle or ring of plates, the
strongest and most durable bosh is obtained (rivetted jackets not excepted) and a
water cooled jacket that will positively hold the original lines of the furnace intact
and uniform, thereby insuring satisfactory and regular working of furnace, large
and continuous output, and low consumption of fuel.
I prefer to make these plates of bronze, copper, or other material not liable
to corrode, but do not limit myself to this, as they can be made of iron.
If
I do not limit myself to horizontal water courses, as shown in Figure 2, these
being preferable, however, and making the strongest plate for all purposes.
desired, vertical ways, as shown in Figure 8, or both horizontal and vertical, as
shown in Figure 7, can be used. The construction shown in either of the two
latter figures is desirable, where inlet and outlet pipes are required on top or
bottom. If desired, circulation can be obtained as shown in Figure 9, by means of
a partition running from top to bottom, or rice versa. This circulation can be
increased by webs running from one or both sides of these partitions, as shown in
Figures 2, 7 and 8. Where increased circulation is desired two or more feed
openings can be used.
I do not limit myself to the use of this jacket to cooling a furnace from mantel to
tuyeres only. It may be employed above the mantel and between and below the
tuyeres, whereby it will prevent the frequent breaking out of the furnace near its
bottom.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is
1. In a blast furnace, the combination with a furnace, of a series of hollow plates
or sections secured around the furnace, said plates or sections each provided with a
system of tortuous water courses and also provided upon their outer surfaces with
inclined lugs, bands encircling said plates or sections and engaging the lugs, and

page_text: wedges or keys inserted between the bands and the lugs, substantially as set
forth.
2. In a blast furnace, the combination with the furnace, of a series of hollow
plates secured around the same, said plates consisting of front and back walls, and
closed edges with a series of webs or partitions intervening to form tortuous water
passages, extending throughout the entire plate, and also having suitable inlet and
outlet openings for said passages, substantially as set forth.
3. A cooling plate for blast furnaces, consisting of front, rear, and edge walls,
and internal webs or partitions cast integral therewith so as to form tortuous
water passages and arranged so that free circulation of the water may be secured
from one passage to another, extending throughout the entire plate, substantially as
set forth.
4. A cooling plate for blast furnaces, consisting of front, rear and edge walls,
and internal webs or partitions, cast in one piece, and forming water courses
through the entire plate, said partitions being of less length than the plate and
having one edge only connected to the edge walls thereof, said connecting ends
alternating, substantially as set forth.
Dated this 19th day of May 1801
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.