US3782893A

US3782893A - Multiple pedestal furnace installation

Info

Publication number: US3782893A
Application number: US00255785A
Authority: US
Inventors: C Blackman
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-05-22
Filing date: 1972-05-22
Publication date: 1974-01-01
Anticipated expiration: 1991-01-01

Abstract

A furnace structure and multiple pedestal base installation for heat treating stacked coils of strip material. The pedestals are insulation lined to support the coils, and are supported above the working floor. An elastimeric seal is provided around each pedestal for the reception of a bell inner cover. The furnace structure has support means defining a furnace which has insulation lining substantially totally enclosing the top and sides thereof and defining the bottom with openings therein for reception of the bell covers therethrough. Heating means are carried by the interior of the furnace, but the bottom insulation protects the seals and bottom of the bell covers cooperating with the seals from direct radiation therefrom.

Description

United States Patent [1 1 Blackman Jan. 1,1974

[ MULTIPLE PEDESTAL FURNACE INSTALLATION [22] Filed: May 22, 1972 [21] Appl. No.: 255,785

Primary Examiner-John J. Camby Att0 rney-William N. Hogg [5 7] ABSTRACT A furnace structure and multiple pedestal base installation for heat treating stacked coils of strip material. The pedestals are insulation lined to support the coils, and are supported above the working floor. An elastimeric seal is provided around each pedestal for the reception of a bell inner cover. The furnace structure has support means defining a furnace which has insulation lining substantially totally enclosing the top and sides thereof and defining the bottom with openings therein for reception of the bell covers therethrough. Heating means are carried by the interior of the furnace, but the bottom insulation protects the seals and bottom of the bell covers cooperating with the seals from direct radiation therefrom.

9 Claims, 4 Drawing Figures MULTIPLE PEDESTAL FURNACE INSTALLATION BACKGROUND OF THE INVENTION This invention relates generally to heat treating devices, and more particularly to multiple pedestal belltype heat treating installations in which a removable outer furnace is employed.

The use of multiple pedestal bell-type heat treating installations is a well known well accepted practice in the art of heat treating coils of strip material, such as coiled steel strip. Conventionally such installations include a plurality of pedestals having insulation and charge support means thereon for the reception of stacked coils of material. A seal, normally a sand seal, is provided around each pedestal, and bell-type inner covers are provided for each pedestal, each adapted to be in place over a stack of coils with the lower rim thereof sealing in the sand seal around a respective pedestal. Firebrick or other heat insulation surrounds and fills the space between each of the pedestals. An open bottom insulation lined furnace is then placed over the bell inner covers to provide the heat source.

The furnace is heated until the desired temperature is obtained and held for the prescribed period. The furnace is then removed for the cooling cycle. Such an installation is shown in U.S. Pat. No. 3,497,193 dated Feb. 24, 1970, entitled Multi-Pedestal Bell-Type Annealing Furnace.

These types of multiple pedestal bases have performed quite well where volume and output of heat treatment warrants their installation. However, they do have certain drawbacks which impair their efficiency and somewhat limit their usage. One of these drawbacks is the large amount of insulation required on each base around the pedestal beneath the furnace. This results in a substantial added expense requiring this insulation on all of the bases. Also, this insulation has to be heated each time the furnace is heated, thus requiring additional fuel and time. Also, this insulation limits the amount of working floor space around the pedestals making much of it unavailable to set down the bell inner covers when they have been removed.

Also, because of their location, the seals around each pedestals have necessarily conventionally been sand seals which is undesirable for several reasons. First, it is necessary to keep the sand away from the coils being heat treated since the sand can produce unwanted surface defects in subsequent rolling operations. Also, sand seals must be carefully and frequently cared for to maintain proper sealing efficiency. Also, with sand seals it is not practicable or often not even possible to provide a water spray on the bell inner covers during the cooling cycle to increase the cooling rate.

SUMMARY OF THE PRESENT INVENTION According to the present invention a furnace structure and base therefore are provided wherein a plurality of pedestals for supporting coiled material are mounted on the floor or other load bearing structure. The pedestals have charge support means to support the coils. The furnace has structural support means defining a furnace shell enclosure for removable placement overlying and surrounding the pedestals with the bell covers in place thereon. Furnace insulating material is carried by the support means internally thereof with the insulating material substantially totally enclosing the sides and top of the furnace and being disposed to define a bottom thereof with openings conforming in shape to and positioned and dimensioned to receive the bell ,covers therethrough and being of a size to substantially totally enclose around the covers when the covers are in place on the pedestal. This structure eliminates the necessity of having insulation around the pedestals. the insulation being maintained within the furnace. This means that the base need not have this insulation lining, the lining being only necessary for the number of furnaces, which is substantially less than the number of bases. Also, the bottom insulation, being contained within the furnace, maintains its heat as does the other insulation in the furnace so that there is less heat loss. Further, this structure allows the inner cover seals to be located so that they are protected from direct heating and therefore permits the use of solid or other non sand seals.

DESCRIPTION OF THE FIGURES FIG. 1 is a plan view partially in section of a furnace in place over a four pedestal base according to this invention;

FIG. 2 is a side elevational view partially in section of the structure of FIG. 1;

FIG. 3 is a sectional view taken substantially along the plane designated by the line 33 of FIG. I; and

FIG. 4 is a perspective view somewhat diagramatic of the furnace being placed over bell covers supported by the base.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing, a furnace structure and associated base structure according to this invention are shown. The invention is described in conjunction with a four pedestal base; however, it will be un derstood that it is equally applicable to any number of multiple pedestal bell-type annealing furnace installations.

In the preferred embodiment four pedestals designated generally as 10 are provided which are defined by structural support members 12 mounted on I beams 14 supported on a working floor 15. Each structural support member 12 is provided with insulation 16 with a charge support structure 17 positioned to support the coiled strip of material C thereon. The structural support member 12 of the base also defines an annular channel 18 thereon. At the bottom of the channel 18 is an annular elastimeric seal 20 formed of natural or synthetic rubber or other suitable elastimeric material. The annular channel 18 is in part defined by an outer upstanding steel ring 22 through which extends a discharge pipe 24.

A conventional fan motor 26 is secured to the base to drive a fan (not shown), the fan motor 26 extending into an access pit shown at 28.

Bell-type inner covers designated generally as 32 are provided foreach of the bases and are adapted to overlie the stacked coils C on the bases to enclose the coils therein for proper atmosphere control. Each of the bell covers 32 includes a cylindrical side shell and top domed portion 34 which covers the coils and a sealing band 36 disposed around the lower rim thereof. The sealing band 36 has a hollow interior 38 for the reception of cooling fluid and a lower surface 40 which is adapted to rest on and thereby seal against the seal 20.

A water inlet pipe 42 supplies cooling water to the interior 38 of the band 36. The inlet pipe 42 has a quick disconnect coupling 44 adapted to connect to a water supply 46. The inlet pipe 42 is positioned so that it will extend through a slot 48 provided in the outer ring 22 when the bell cover is properly positioned. The sealing band 36 also has an outlet opening 50 to provide for the discharge of cooling water.

Thus when the bell cover 32 is in place, the sealing area thereof can be water cooled by providing water to the interior 38 thereof through the inlet pipe 42, the water being discharged through the outlet 50 into the channel 18 from which it will discharge through discharge pipe 24. The bell-type covers 32 are provided with conventional lifting lugs 52 to allow for them to be removed and placed properly.

A removable furnace structure 56 is provided for removable placement over the pedestals with the bell covers 32 thereon. The furnace structure includes a steel top plate 58, steel side plates 60, steel end plates 62, and a steel bottom plate 64, which plates together define structural support shell. The top, side and end plates are solid, whereas the bottom plate 64 is provided with a series of four apertures 66, each being of a size and configuration to surround a bell inner cover when positioned on a pedestal 10 when the furnace is in place. The interior of the plates is lined with insulation 68 with the lining on the bottom plate 64 having apertures 70 corresponding in size and shape to the apertures 66 and the steel bottom plates 64. Thus when the furnace structure 56 is in place over the pedestals and over the bell covers, the bottom plate 64 thereof will rest on the outer ring 22 of each of the pedestals 10 providing structural support therefor.

A plurality of burners 72 are provided in each of the side plates 60, the burners being supplied by manifolds 74 which are adapted to be connected to a source of fuel supply. These manifolds are shown only diagramatically, their specific construction not being a part per se of the present invention. Also, it is to be understood that electric heating means, radiant tubes, or other heat sources could also be employed rather than burners. It will be noted that with the furnace structure in place the insulation 68 on the bottom plate 64 of the furnace extends inwardly toward the bell cover 32 providing an annular shielding surface 75 at a location between the burners 72 and the seal 20. Thus the seal is protected from direct radiation from the burners and the radiation furnace side walls. This protection, together with the cooling of the sealing band 36 where required, provides adequate protection so that solid elastimeric seals or liquid or other low temperature seals can be utilized in place of more conventional sand seals.

In order to guide the furnace structure 56 into place properly a pair of guide posts 76 are provided which are secured to the working floor and extend upwardly therefrom. These guide posts are positioned to cooperate with a pair of guide collars 78, one of which is located on each of the side plates 60 and which are located to slidably engage the guide posts 76 to accurately guide the furnace into position as it is being lowered (as shown in FIG. 4) into position. The furnace structure 56 is raised and lowered by means of a conventional lifting eye 80 mounted on the top plate 58 and located to be engaged by a crane hook as shown in FIG. 4.

Thus it can be seen that with a furnace structure and base constructed according to this invention a plurality of pedestals are provided which have insulation thereon but which do not require insulation therearound between the pedestals, thereby providing working area immediately adjacent the pedestal. The insulation lining on the bottom of the furnace provides the necessary insulation during heating, and when the furnace is removed it is not necessary to wait for insulation surrounding the furnace to cool before working therearound. Further, the heat required to heat the firebrick is not wasted, since this heat is retained within the furnace, which furnace, in the majority of the cases, is used immediately on another base so that the retained heat is actually utilized in a subsequent heating operation. Also, one furnace can serve several base installations, thus not requiring a multiplication of the amount of insulation required as is the case when each base is insulated.

It will further be noted that this construction of the furnace with the insulation on the bottom allows a solid seal to be used in place of conventional sand seals. This removes one of the major undesirable features of prior art conventional multiple stack base installations. By utilizing the solid seal in place of sand the danger of sand contaminating the coils thus is eliminated. Further, when this type of seal in the furnace structure has been removed, cooling water spray can be directed against the bell-type covers to assist in the cooling with the channel 18 collecting and disposing of the water which may drain off the inner covers.

Thus an improved multiple pedestal bell-type furnace installation is provided which retains the desirable features of the prior art but overcomes many of the drawbacks and limitations thereof.

What is claimed is:

1. A furnace structure for an annealing furnace assembly, wherein a plurality of pedestals for supporting coiled material are provided, and wherein each pedestal has associated therewith a seal for the reception of a bell-type cover,

said furnace structure comprising,

structural support shell defining a movable furnace enclosure for removable placement overlying and surrounding the pedestals with bell covers in place thereon, insulating material carried by said support means internally thereof, said insulating material substantially totally enclosing the sides and top of said furnace structure and being disposed to define a bottom thereof with means forming individual spaced openings conforming in shape to and positioned and dimensioned to receive the bell covers individually therethrough and being of a size to substantially totally enclose around said covers when said covers are in place on the pedestals, and heating means carried internally of said furnace structure.

2. The invention as defined in claim 1 wherein the bottom of said furnace structure is positioned and shaped to shield the seals from direct heat radiation from said heating means.

3. The invention as defined in claim 1 further characterized by guide means to guide said furnace structure into place over said bell covers.

4. The invention as defined in claim 3 wherein said guide means includes cooperating post means and collar means.

5. An annealing furnace assembly comprising, a pluenclose around said covers when said covers are in rality of pedestals mounted on a structural support, place in the pedestals, and heating means carried each pedestal having means for supporting coiled mateinternally of said furnace structure. rial, a seal surrounding each pedestal for the reception 6. The invention as defined in claim 5 wherein the of a bell type cover, 5 bottom of said furnace structure is positioned to shield structural support shell defining a movable furnace the seals from direct heat radiation from said heating enclosure for removable placement overlying and means. surrounding the pedestals with bell covers in place 7. The invention as defined in claim 6 wherein the thereon, insulating material substantially totally enseals are solid seals. closing the sides and top of said furnace structure 10 8. The invention as defined in claim 6 wherein liquid and being disposed to define a bottom thereof with cooling means for the seals are provided. means forming individual spaced openings con- 9. The invention as defined in claim 5 further characforming in shape to and positioned and dimenterized by trough means around each of said pedestals sioned to receive the bell covers individually therefor the collection of water. through and being of a size to substantially totally 5

Claims

1. A furnace structure for an annealing furnace assembly, wherein a plurality of pedestals for supporting coiled material are provided, and wherein each pedestal has associated therewith a seal for the reception of a bell-type cover, said furnace structure comprising, structural support shell defining a movable furnace enclosure for removable placement overlying and surrounding the pedestals with bell covers in place thereon, insulating material carried by said support means internally thereof, said insulating material substantially totally enclosing the sides and top of said furnace structure and being disposed to define a bottom thereof with means forming individual spaced openings conforming in shape to and positioned and dimensioned to receive the bell covers individually therethrough and being of a size to substantially totally enclose around said covers when said covers are in place on the pedestals, and heating means carried internally of said furnace structure.

5. An annealing furnace assembly comprising, a plurality of pedestals mounted on a structural support, each pedestal having means for supporting coiled material, a seal surrounding each pedestal for the reception of a bell type cover, structural support shell defining a movable furnace enclosure for removable placement overlying and surrounding the pedestals with bell covers in place thereon, insulating material substantially totally enclosing the sides and top of said furnace structure and being disposed to define a bottom thereof with means forming individual spaced openings conforming in shape to and positioned and dimensioned to receive the bell covers individually therethrough and being of a size to substantially totally enclose around said covers when said covers are in place in the pedestals, and heating means carried internally of said furnace structure.

6. The invention as defined in claim 5 wherein the bottom of said furnace structure is positioned to shield the seals from direct heat radiation from said heating means.

7. The invention as defined in claim 6 wherein the seals are solid seals.

8. The invention as defined in claim 6 wherein liquid cooling means for the seals are provided.

9. The invention as defined in claim 5 further characterized by trough means around each of said pedestals for the collection of water.