Easily stored and used disposable cover for a molten metal ladle

An easily stored and used disposable cover for the opening of a molten metal type ladle is disclosed, which uses transverse ribs of green hardwood above a blanket made up of ceramic fabric batting. The ribs are tied together into an array by means of flexible wires running longitudinally across the ribs and secured to them. The ribs are sized to span across the ladle opening and to hold the blanket thereover, and the cover may be easily rolled up longitudinally so as to assume an easily stored, handled and shipped roll shape. A plurality of wide headed nails hold a sheet of plastic or like material and the blanket to the ribs. The sheet serves to protect the blanket from tearing or catching or binding together and allows it to be unrolled and handled more easily. A wire end handling loop is also provided at the longitudinal ends to aid in placing the cover over the ladle.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to the art of closures for ladles of the type used 
for carrying molten metal, including ladle cars and, more particularly, to 
a new and improved disposable cover for closing the opening of a preheated 
ladle car for retaining the heat therein after heating and before pouring 
molten metal therein. 
2. Description of the Prior Art 
The present invention finds its primary use with ladle cars, also called 
torpedo cars from their shape, transfer cars from their function, and Pugh 
ladles after their originator (U.S. Pat. No. 1,488,436). Such ladles are 
used in steel mills and like plants for moving molten metal from one 
location to another, for example, from a blast furnace to a continuous 
caster. U.S. Pat. No. 3,661,374 depicts one such ladle car. The cars have 
an opening and are conventionally rotatable along their long axis for 
discharging metal from the opening. Such cars, as is the case with 
conventional ladles for molten metal, are lined with a refractory 
material. To prevent damage to this material when the extremely hot molten 
metal is poured into the ladle, the ladle is conventionally preheated. 
This is often done by inserting gas burners into the opening of a 
partially rotated ladle and heating the interior over a period of time to 
raise the lining temperature. 
Now it often occurs that the heating station for the ladle is located a 
good distance from the source of metal or that because of scheduling 
delays or convenience in use, the car may have to wait a period of time 
before it is used. While permanent covers for ladles (e.g., U.S. Pat. No. 
1,488,026) and Pugh ladles (U.S. Pat. No. 4,298,191) have been suggested, 
in practice, it is more efficient to prevent the waste of heat and, more 
importantly, the lowering of the lining termperature by using disposable 
lids or plugs. 
Such coverings can also be used to cover molten metal containing ladles to 
prevent heat loss from the metal during transfer. In use, molten metal is 
poured through such coverings (melting upon contact the coverings and 
chicken wire). 
A third and major use of such a covering is to conserve heat and maintain 
the temperature of a ladle after it has discharged its load of molten 
metal and while it is being returned for a second load. 
It has been the practice to use ceramic batting reinforced in one or both 
sides with chicken wire. In one common form, this takes the shape of an 
oval or rectangular blanket that is laid over the mouth or opening of the 
ladle car. Such oval blankets are stored and shipped folded over in a 
half-moon shape. 
In use, these blankets tend to sag or deform as the chicken wire stretches 
and softens as its temperature rises, tending to form an opening or 
openings through the blanket. Also, the lightweight blanket tends to blow 
off, partially or wholly, when subjected to gusts of winds often present 
in and around steel mills, especially when the car is being moved about, 
e.g., from the preheating station to a blast furnace. Thus, openings tend 
to form, resulting in a loss of heat. 
It has also been suggested in U.S. Pat. No. 4,390,170 entitled Closure Plug 
for Ladle Car to form the chicken wire blanket into a conical shape that 
plugs the opening more or less like a cork in a bottle. 
However, this construction would also tend to sag, especially as the 
chicken wire is placed on the underside of the plug. When used as 
described over ladle cars filled with molten metal, there is the 
possibility of having the plug bottom dissolved by contacting the molten 
metal. 
One disadvantage of such prior closures is the difficulty of handling, 
storing, and transporting them. The typical blanket may be about 
6.times.10 feet in size and even when folded over is a 6.times.5 foot 
unit. The conical shape suggested by the above-mentioned patent, while 
perhaps stackable in a nested array, would still be bulky and difficult to 
store, ship, and handle. Further, the ceramic batting of the insulation is 
relatively fragile and easily torn by contact with sharp edges or points 
during storage and handling. Thus, bulkiness in storage and difficulty in 
handling are significant disadvantages. Further, the chicken wire surface 
tends to "grab" or snag easily, making handling, as well as stacking or 
nesting, difficult. 
Also, the unprotected insulation of prior covers while relatively 
non-absorbent of moisture, if exposed to rain or other sources of water 
during storage or handling, can entrap water droplets. This liquid when 
exposed to the high heat as when the cover is placed over a hot ladle can 
flash into steam with resulting damage to the insulation. Moisture can 
also cause the cover to deteriorate while in storage. 
SUMMARY OF THE INVENTION 
In overcoming one or more of these disadvantages of the prior art, the 
present invention provides for a heat-retaining, disposable cover for a 
ladle having an opening for receiving molten metal, which cover includes a 
blanket of flexible ceramic batting insulating material sized and shaped 
to cover and overlap the ladle opening; a plurality of rigid transverse 
support ribs, such as supports of hardwood positioned generally parallel 
to one another and spaced along the top of the blanket and secured cured 
to it, the ribs being sized to at least span the ladle opening when the 
cover is positioned on it, and flexible longitudinal supports such as a 
pair of spaced apart transverse steel wires affixed to the ribs for 
preventing them from transversely spreading and for securing them 
together; and means for allowing the cove to be easily secured to the 
ladle, whereby the cover may be rolled up transversely for ease of storage 
and transport and still be easily unrolled and dropped in place and 
secured over the ladle opening. 
The present inventor has discovered that hardwood ribs of aobut 
1.times.11/4 inches when used as taught by the present invention, do not, 
even after hours of use of the cover over a heated ladle, burn or weaken, 
nor tend to sag. Yet, when molten metal is poured through the cover, the 
ribs are readily consumed, offering no hindrance to the use of the ladle. 
In accordance with another feature of the invention, a layer of plastic, or 
like consumable sheet material, is provided secured to the bottom of the 
blanket. This provides some structural strength and a smooth bottom 
surface to aid in rolling up the cover for storage and makes it easily 
handled as it reduces the propensity of the rolled or unrolled cover to 
snag or catch on objects. The layer of plastic also acts as a waterproof 
cover. This protects the cover from moisture and water while in transit, 
as well as in storage. 
Additional features of the present invention which are believed to be novel 
are set forth herein-after. The invention, together with the further 
advantages thereof, may best be understood by reference to the following 
description taken in connection with the accompanying drawings, in the 
several figures of which like reference numerals identify like elements.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, there is depicted an easily stored and used disposable 
cover constructed in accordance with the principles of the present 
invention, and generally designated by the number 10. The cover 10 is 
shown in its open or unrolled configuration as it would appear laid out on 
a floor or other flat surface 12 facing upward. In use, the cover 10 is 
placed over a ladle, with its bottom surface downward covering the 
opening. 
The cover 10 comprises a blanket 14 formulated of flexible ceramic fiber 
insulating material batting. Such batting is available form the 
Carborundum Company of Niagara Falls, New York under the trademark 
Durablanket and also from Babcock & Wilcox Co., Insulating Products 
Division, Augusta, Georgia, under the trademark Kaowool. The blanket 14 
may be formed of overlapping batting sections 14A and 14B as shown in FIG. 
1, so as to gain a sufficient width. Basically, the blanket is sized to 
overlay on all sides of the ladle opening when placed centrally thereover 
and, thus, its dimensions depend on the ladle opening. A typical ladle 
opening on a Pugh car may be approximately 6.times.8 feet. For such an 
opening, a blanket 14 approximately 7 feet 6 inches by 10 feet has proven 
entirely satisfactory. 
In accordance with one feature of the present invention, the cover 10 is 
provided with a plurality of transverse ribs 16 made of green hardwood, 
such as oak, which spans across the top of the blanket 14. The ribs 16 are 
arranged parallel to each other and are sized in length so as to also span 
the ladle mouth or opening when the cover is placed over it. The ribs 16 
are preferably of a square or rectangular cross-section with 1.times.11/4 
inches size being adequate for the particular sized blanket mentioned 
above, and are generally spaced apart from each other by an equal amount. 
The extreme ribs 16' are preferably spaced at a shorter distance from 
their adjacent ribs 16 and are somewhat shorter in length. 
The ribs 16 are prevented from spreading apart from each other by means of 
flexible but relatively inelastic ties 20 which run perpendicular to the 
ribs 16 and are secured thereto at the points 22 of crossing the ribs 16. 
Seventeen-gauge steel wire is one example of suitable tying means 20. The 
ties 20 are preferably secured at about one-quarter and three-quarters of 
the transverse width of the cover 10, and serve to tie the ribs into a 
flexible framework that can be easily rolled up. 
Means for handling the cover 10, namely, handling loops of wire 22 and 22' 
are provided at each end of the cover. These are preferably continuations 
of the tying wires 20. These handling means 22, 22' allow the cover 10 to 
be picked up and moved onto the ladle opening without the necessity of a 
worker closely approaching the hot opening. 
As also shown in FIG. 1, the four corners of the cover 10 are provided with 
expanded metal mesh areas 30 on their upper surfaces. These areas 30 are 
secured to the ends of the shortened ribs 16' as by stapling or in any 
other convenient and effective manner, and serve as a nailing surface for 
allowing the corners to be nailed down onto the outer surface of a ladle 
by a stud gun. 
While shown on the preferred expanded metal mesh, millboard and even burlap 
fabric could be used so long as the material of the surfaces 30 is 
sufficiently strong as to be boundable to the ribs 16' and to receive and 
hold the stud. 
Referring to FIG. 2, there is depicted a portion of the underside or bottom 
of the cover 10. Also shown are the means for securing the ceramic blanket 
14 to the ribs 16, namely, a plurality of wide-headed nails 18. Such nails 
18 may be made in one piece or formed by using a conventional headed nail 
and a suitable washer, e.g., one of thin metal sheet. 
As also shown in FIG. 2, the nails 18, also in accordance with one feature 
of the invention, secure a thin layer of sheeting 28 which is, as shown, 
preferably 4 mil. eurothane plastic sheeting, but may also be made of 
cloth, e.g., cheese cloth. The purpose of the sheeting is to protect the 
ceramic blanket 14 while providing a smooth, non-snagging bottom surface 
for allowing the cover bottom to easily slide over obstacles. Further, 
when rolled up for storage or shipping as shown in FIG. 3, the sheeting 28 
is on the outside of the roll and serves to protect the cover. The 
sheeting, of course, that is exposed to the ladle opening, will readily 
and quickly vaporize and burn off, however, this represents no particular 
problem in use as it is the ribs 16 and ties 20 that provide the strength 
for the cover to span over the ladle opening. 
As also shown in FIG. 3, the rolled-up cover 10 is preferably secured in 
its rolled up state by straps 29. 
As shown in FIG. 4, the cover 10 is positioned over a ladle opening 40 and 
is being secured by a stud gun 42 which is driving a stud or nail through 
the area 30. It may also be secured by means of a simple reusable hook and 
spring 15 affixed to the ladle 50 and capable of hooking on to the loop 22 
or 22'. 
Prior to the use and for storage and shipping, the novel cover 10 would be 
in the rolled-up state of FIG. 3. When desired to be used, it need only be 
unrolled to assume the state of FIG. 1 and by hand or machine lifted above 
a ladle 50, draped over its opening, and secured as shown in FIG. 4. 
It should now be apparent that a new and improved disposable cover for a 
ladle has been described that is easy to handle, store, ship, and use 
while still providing effective heat retention, and is yet simple and 
inexpensive to make and use. 
While particular emphasis has been placed herein on the embodiment 
illustrated in the drawings and certain modifications thereof, it will be 
appreciated that other embodiments of the invention as well as other 
modifications of the embodiment herein illustrated and described can be 
made without departing from the principles of the present invention. 
Accordingly, it is to be distinctly understood that the foregoing 
descriptive matter is to be interpreted merely as illustrative of the 
present invention and not as a limitation.