MXPA00012709A - Convertible apparatus for heat treating materials - Google Patents

Abstract

A heating system for heat treating a continuous sheet-like material includes an input endand an output end and a path defined therebetween that extends between the input and output ends for the material to be treated. At least one section of the heating system includes an upper movable heater and a lower stationary heater disposed on confrontingly opposite sides of the material path. A heater lifter is connected to the movable upper heater for operatively displacing the upper heater between a first position for imparting a curing type of heat treatment and a second position for imparting an annealing type of heat treatment to the continuous sheet material as it is advanced through the heating system.

Description

CONVERTIBLE APPARATUS TO TREAT HEAT MATERIALS BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates to an apparatus for heat treatment of a continuous sheet material and which is convertible in a configuration to effect different types of heat treatment.

DESCRIPTION OF THE RELATIVE TECHNIQUE In manufacturing industries, ovens and stoves are used to apply various types of heat treatment to obtain properties and desired behaviors of different materials, such as metals, metal alloys, ceramic materials, glass, cellulose, resins. Synthetic and other manufacturing materials Processing of different sizes and types of materials requires that the time and / or temperature of the heat applied to the material be selectively adjusted to effect a specific heat treatment with a given result. A particular process may also require separate stages of heat treatment of a material at different temperatures and different periods of time. In general, heat treatment by furnaces includes preheating, annealing, normalizing and tempering a metal strip or sheet, and treatment with stoves (kilns) includes drying and curing a coating applied on a material. The processing industry uses these separate and distinct heat treatment process lines to carry out the different types of heat treatments because they are performed at significantly different temperatures and use significantly different material processing configurations. For example, the temperature required to cover a coating, such as paint, on a material and the manner of handling the material during processing differs greatly from the temperature and handling required to anneal a metal tape. The apparatus conventionally used for the type of heat treatment for curing is referred to as a curing oven 120 (Figure 6). The curing oven 1 20 comprises a coater 1 29 for applying a coating to a continuous material and the heaters 121 a and 1 21 b opposingly facing to cure the coating on the continuous material. The curing oven 1 20 typically operates with air supply temperatures below 538 ° C so that the material reaches a temperature of 232 ° C to 288 ° C. The apparatus used for the type of heat treatment for annealing, on the other hand, it is referred to as an oven 120 'for annealing as for example that shown in Figure 7. The annealing furnace 1 20' comprises opposed heaters 1 21 a 'and 121 b' placed in close proximity to the material path continuous through the 120 'annealing oven. The furnace 120 'operates typically with air supply temperatures above 538 ° C and the material must reach temperatures in the range of 466 ° C to 583 ° C for annealing. In addition to these markedly different operating temperatures, another difference between the curing and annealing processes is that in the curing oven, the continuous material is suspended between the inlet and the outlet and assumes a free hanging catenary path that spans the full length of the oven; This ensures heating of all surfaces and surface portions and prevents damage to the coating as it dries and cures. Since the position of the free hanging tape is not stabilized, and the tape tends to be bagged and tilted transversely along its unsupported length, the heaters must be placed at an appropriate distance from the tape to avoid inadvertent contact and, as a result, only a small or fractional portion of the available energy emitted from each heater is actually applied to the belt. In contrast, the material passing through the annealing furnace is supported along the entire substantially horizontal path with the heaters allowing it to be placed in close proximity to the material to maximize the available heat energy that is applied to the material. tape. Because the configuration of the process line required for heat treatments of the curing and drying type is markedly different from the configuration required for heat treatments of the annealed type, the heat treatment industries, use separate and different heat treatment equipment and a separate process line for each type of heat treatment. As a consequence, preheating, annealing, normalizing and tempering are typically performed by the continuous raw material manufacturer and drying and curing of coatings are typically performed in a separate coating facility. The prior art devices used to regulate the operating temperature of the ovens and stoves used for heat treatment include controlled regime devices that vary the rate at which the material being treated passes through the oven and / or stove; feeding and advancing the continuous metal belt slows down considerably if a high temperature is required, thereby increasing the processing time. Other prior art devices include plural heaters positioned along the processing line and individually placed and removed as a function of the temperature required for heat treatment. Although the treatment temperature ranges are therefore somewhat adjustable, none of the prior art devices are convertible from an annealing-type processing configuration to a curing-type processing configuration.

BRIEF DESCRIPTION OF THE INVENTION Accordingly, it is an object of the present invention to provide an apparatus or installation for simple heat treatment that is operationally convertible from a first processing configuration to impart a heat treatment of the curing type for a material. continuous to a second processing configuration for imparting a heat treatment of the annealing type to a continuous material by, inter alia, altering the spacing of heaters movable selectively from the material advance path through the heat treatment apparatus, using with this a single process line for both types of heat treatment processes. In a preferred embodiment of the invention, the system or apparatus for heating a process line for heat treatment to heat treat a continuous material includes a heater selectively movable in at least a first section of the heating system. A heater lifter mechanism selectively moves the movable heater by two transverse directions substantially to the direction of advance of the continuous material between a heat treatment position for annealing and a heat treatment position for curing. In the annealing position, the heater is positioned relatively close to the continuous material to impart the greatest amount of heat to the continuous material, while in the curing position the heater is placed farther apart from the continuous material to avoid damage to the continuous material and impart a reduced amount of heat with this. Furthermore, in the annealing position, the continuous material is supported by floating-type nozzles so that the air forced into the continuous material by the floating-type nozzles supports the continuous material so that it advances through the heating system. . In the curing position, on the other hand, the continuous material is not supported by the flotation nozzles and thus a catenary bag is formed between the inlet and outlet ends of at least the initial section of the container. heating system that includes the movable heater. The movable heater may be disposed in any position or location around the advancing path of the continuous material, but preferably it is above the path and in opposition to a stationary heater placed in opposite facing condition on the opposite side, preferably by below, of the continuous material. Other objects and aspects of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It should be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should further be understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are only intended to conceptually illustrate the structures and methods described herein.

BRIEF DESCRIPTION OF THE DIAMETERS In the drawings, where the similar reference characters indicate similar elements in all the different views: Figure 1 is a diagrammatic view of a process line including a heating system according to a embodiment of the present invention; Figure 2 is a diagrammatic view of the heating system of the process line of Figure 1; Figure 3 is a diagrammatic view of a first section of the inventive heating system of the process line shown in Figure 1 in the annealing material processing condition; Figure 4 is a diagrammatic view of the first section of the inventive heating system of the process line shown in Figure 1 in the material curing processing condition; Figure 5 is a schematic block diagram of a control system for the inventive heating system; Figure 6 is a diagrammatic view of a curing oven of the prior art; and Figure 7 is a diagrammatic view of an annealing furnace of the prior art.

DETAILED DESCRIPTION OF CURRENT MODALITIES PREFERRED With reference initially to Figure 1, a process line 1 00 according to the present invention for thermally treating a continuous material 50 includes an inlet section 10, a heating system 20, and an outlet section 30. The continuous material 50 may comprise, by way of non-limiting example, a sheet, strip or continuous band of metal, an alloy of metal, ceramic, resin, cellulose, glass or any other material capable of being formed into a strip or band. keep going. The continuous material 50 is manually fed horizontally and advances longitudinally through the process line 100 for the desired treatment of the tape. The inlet section 100 typically includes an inlet coil 1 1 of or clamping the continuous material 50 to be heat treated, an inlet accumulator 12 accommodating an elongated section or length of the continuous material 50, and a device 1 3 for washing / chemical treatment. When the inlet coil 1 1 runs out of the continuous material 50, the length of the continuous material 50 in the aquifer 1 2 continues to supply material to the heating system 20, thereby allowing a new coil to be mounted or connected. input without interrupting the flow of the continuous material 50 through the heating system 20. With the new input coil in place, the input of continuous material 50 to the accumulator 1 2 is resumed and the accumulator arms accumulate radically extended length of material 50 as shown in Figure 1. The scrubber / chemical treatment device 1 3 ensures that the continuous material 50 is properly prepared for the subsequent heat treatment in the heating system 20. The heating system 20, which will be described in more detail below, comprises a housing 80. formed by a plurality of interconnected thermal box panels and enclosing first, second and third heating sections 70, 71 and 72. Sections 70, 71, 72 are separated by first and second barriers 81 and 82. Each of the heating sections 70, 71, 72 comprises upper and lower heaters 21 a and 21 b, 22 a and 22 b, and 23 a and 23 b facing each other that are operable to heat the continuous material 50 as it advances longitudinally through the heating system 20 towards the outlet section 30. A heater lift mechanism 25 is operable to move or move the upper heater 21 to respective It made you and away from the path of the continuous material 50 to selectively adjust with this the processing pattern and heat treatment characteristics imparted to the continuous material 50 as it proceeds through the heating system 20. The heater lift mechanism 25 includes a cable drum 65 mounted rotatably in the housing 80 above the upper heaters 21 a. The cables 63 connected between the cable drum 65 and the upper heater 21 a support the vertical position of the heater above. Although a drum 65 of cable and cables 63 is shown, the heater lifter mechanism 25 may comprise any vertically adjustable mechanical support capable of supporting and moving the upper heater 21 a. Optional position rollers 40 positioned upstream and downstream of the heating system 20 help to direct or redirect the continuous material 50 as it travels from one part or section of the process line 100 to another. Although the heating system 20 as described herein includes three successive processing sections 70, 71, 72, those skilled in the art will recognize that the invention is equally applicable to heating systems and arrangements that incorporate more or less such processing sections. In fact, the arrangements in which the heating system 20 has only a single section 70 for processing moving heaters are within the scope and contemplation of the invention. Thus, the use of three sections in the particular embodiment described herein is intended as an illustrative example and should be understood to be preferred, but not required in the practice of the invention. The outlet section 30 includes a cooling device 31, an outlet accumulator 32, similar to the inlet accumulator 12, and an outlet coil 33 in which the thermally treated continuous material 50 is wound. Depending on the type of heat treatment imparted to the continuous material, the cooling device 31 may or may not be required for a particular application or implementation. When the output coil 33 is complete, the output accumulator 32 allows the complete output coil to be removed and a new output coil placed in place without interrupting the flow of the continuous material 50 through the heating system 20. The output accumulator 32 thus operationally accumulates the continuous material 50 received from the heating system 20 without its exit from any received material while the complete output coil is exchanged for an empty one. The new coil can then gradually accommodate the loose length of continuous material 50 that accumulated in the output accumulator 32 during the coil change. Referring now to Figure 2, the first heating section 70 of the heating system 20 of the present invention includes three upper heaters 21 a and three lower heaters 21 b. Of course, the illustration and description of three of each or both of the upper and lower heaters 21 a and 21 b is by way of example only and one or more of each could be used instead as a function, for example, of the requirements of heat treatment temperature, the heating capacity of heaters and other design and processing considerations. In any case, each of the upper heaters 21 a and lower heaters 21 b can and will typically be implemented as a manifold that receives heated air from a heat source via a duct and directs the heated air to the continuous material through a nozzle plurality 26. The number of nozzles 26 in each heater can also be varied according to the requirements of the particular heat treatment to be imparted to the material. The nozzles 26 provide the dual function of supporting the continuous material 50 while providing heat to the continuous material 50 by directing a stream of hot air towards the opposite surfaces of the continuous material 50. The heat source (not shown) to provide the ca The heaters 21 a and 21 b may be positioned either inside or outside the housing 80 and may, by way of example, comprise an electrical source or a gas burner or the like. From the coater 29, the continuous material 50 enters the heating section 20 in an elevated position relative to the highest roll of the input rolls 40 from which the material 50 enters the heating section in the annealed condition of the device. Those skilled in the art are aware that by processing conventional materials in the conventional curing type, the material advances through the furnace in a generally unsupported condition between the furnace inlet and outlet locations and thus a catenary path between the furnaces. entry and exit supports. Accordingly, in this second condition or curing of the inventive thermal processing apparatus, the continuous belt is unsupported in a similar manner - that is, the continuous material 50 is not supported by hot air (or any) ejected from the lower nozzles. or any other structure - in at least the first section 70 of the heating system 20 and thus assumes a catenary pathgenerally arched in at least that first portion 70 of the heating system 20. Since in order to effect curing the material 50 enters the first section 70 in an elevated position relative to the one in which the material enters the section. 70 for annealing, and to prevent unintentional and potentially damaging contact between the material 50 and the upper heaters 21 a, to process the heaters 21 a with a cured type are raised to their second position or curing, Figure 4, from its annealing position (Fig. 3). The heater lifter 25 which will be described in more detail below, is operable to selectively move the upper heaters 21 a relative to the lower heaters 21 b - which are in the preferred embodiment positively fixed in the housing 8 - between a annealing position shown in Figures 2 and 3 and a curing position shown in Figure 4. It should also be noted that each of the heaters 21 a, 21 b, 22 a, 22 b, 23 a and 23 b can also be optionally movable to an inoperable position by a mechanism other than the heater lifter 25 to provide additional access thereto for maintenance and repair purposes, that is, when the heating system 20 is turned off. The heater lifter mechanism 25, on the other hand, is intended to be used during and in conjunction with normal operating use of the heating system 20 to move the heater 21 between its two operating or material processing positions, i.e. the position of the heater. annealing and curing position. The movable heaters 21 a may be connected to the heat source via, for example, a flexible duct to accommodate the displacement of the heaters 21 a during and in connection with its operation. The others, heaters 21b, 22a, 22b, 23a, and 23b generally final, may be connected to the heat source using any suitable flexible or fixed ducts or plenums. The next heater section 71 is formed by four sets of upper heaters 22a and four sets of lower heaters 22b. Again, the illustration and description of four sets of each of the upper and lower heaters 22a, 22b is by way of example only and any desired or appropriate number of heaters may be used depending, inter alia, on the temperature requirements of the heat treatment and the heat capacity of the heaters. In either case, each of the upper heaters 22a and lower heaters 22b will also typically be formed by a plurality of supply nozzles 26. This second section 70 comprises only heaters of the stationary type and does not include heater lifter mechanism 25 for moving the heaters. The third heating section 72 of the heating system 20 comprises, by way of illustrative example, two sets of upper heaters 23a and two sets of lower heaters 23b. This third section 72 is a cooling section which is used to cool the continuous material 50 to a temperature suitable for post-thermal processing before material 50 leaves the heating system 20. In some types of heat treatment, the function of heating heaters 23a, 23b may be unnecessary or undesirable, in which case ambient air may be directed without heating through nozzles 26 on the continuous material to cool it. In other applications, a predetermined specific temperature of heated air may be applied to the material to control the rate of cooling of the continuous material before it leaves the heating system 20. Figure 3 represents the first section 70 of the heating system 20 in the annealing type processing position or condition in which the mobile heaters 21a are placed in their lowermost locations relatively in close proximity relative to the continuous material 50 for, inter alia, maximizing the radiated heat portion of the heating units 26 which is imparted to the material 50 while allowing the advancing movement without or obstacles of the material 50 as a continuous belt through the heating system 20. Although this is herein referred to as the annealing position, many other types of heat treatments may also be performed in this first position such as, for example, preheating, normalization and quenching. As will be apparent in Figure 3, in the annealing position the sheet of continuous material 50 enters the heating system 20 from the top of the input rolls 40, and comes out in a similar manner (as seen in the Figure 1) of the heating system 20 around the uppermost of the output rolls 40. Preferably, the material 50 is maintained substantially horizontal as it is advanced between the inlet and outlet rollers 40 and, for that purpose, is supported by the hot air which is directed by the nozzles 26 of the lower heaters 21 b, 22b , 23b towards and against the underside or below the material 50 as the sheet. Thus, in the annealing position or condition of the inventive apparatus the flow rate of the hot air expelled from the nozzles 26 of the lower heaters is adjusted to provide sufficient forces directed upward in the material 50 to maintain the material in an orientation substantially horizontal between the exit and entry rollers 40. In an alternate but less preferred arrangement for annealing, the use of air expelled from the nozzles of the lower heater to support the material 50 in the substantially horizontal orientation can be limited to the first section 70 of the heating system 20 (or to a smaller one of all the sections forming the system 20), the support of the sheet being provided in the remaining section (s) by means of rollers or others with known structures for transporting the continuous material as it is advanced by a processing line. As previously noted, the heater lifter 25 is operable to selectively move the upper heaters 21 a in the housing 80 and relative to the positionally fixed lower heaters 21 b and the path of the continuous material 50 between the annealing position of the Figure 3 and the curing position shown in Figure 4. In the curing position of Figure 4, the first section 70 is formed by drying coatings that have been applied to the continuous material 50 such as, for example, paint , lacquers, resins, insulation materials, and coatings resistant to corrosion. Process line 1 00 will also include for this purpose a coater 29 (Figure 4) through which the continuous material flows before entering the first section 70 when process line 1 00 is to be used for drying and curing coatings; the coater 29 applies the coating material to the continuous material 50 and can be derived when the heating system 20 is used for annealing or any other process that does not require the coater 29. From the coater 29, the continuous material 50 enters the section of heating 20 in an elevated position relative to the highest roll of the input rolls 40 from which the material 50 enters the heating section in the annealing condition of the apparatus. Those skilled in the art know that in the processing of continuous materials with conventional curing type, the material advances through the furnace in a generally unsupported condition between the inlet and outlet locations of the furnace and thus assumes a catenary path between the input and output supports. Accordingly, in this second condition or curing of the inventive thermal processing apparatus, the continuous tape is not supported in the same way - that is, the material 50 is not supported by hot air (or any) ejected from the nozzles. lower 26 or any other structure - in at least the first section 70 of the heating system 20 and thus assumes a catenary trajectory, generally arched in at least that first section 70 of the heating system 20. Since to effect curing the material 50 enters the first section 70 in an elevated position relative to that in which the material enters the section 70 for annealing, and to prevent unintentional and potentially harmful contact between the material 50 and the heaters 21 to higher for heater-type processing the heaters 21 a rises to its second position or heats Figure 4 from its annealing position (Fig. 3). A temperature resistance range of the heater lifter mechanism 25 limits the maximum allowable temperature in the first section 70 of the heating system 20 to prevent damage to the heater lift mechanism 25. As a consequence, the higher annealing temperatures required for certain types of continuous material 50 may not be achievable in the first section 70. In those cases, the second section 71 of the heating system 20 - both heating sections the upper one and the lower 22a, 22b are positionally fixed - used to impact the desired elevated heat treatment temperatures for the continuous material 50. Since in such cases the temperatures in the second section 71 are higher than those allowed in the first section 70 , a first barrier 80 can be provided to separate the first section 70 from the second section 71 so that the heater lifter cables 63 are not subject to damaging temperatures. In the same way, a second barrier 81 can separate the second section 71 from the third section 72 so that an appropriately controlled cooling in the third section can be obtained without affecting the higher temperature air in the second section 71. Also within the contemplation of the invention is a convertible heating system having one or more heating sections, wherein each of the heating sections includes a heater 21 at its movable top. However, the heat treatments to be carried out by this modified heating system are limited to those which require no more than the resistance temperature then of the heater lift mechanisms.

Figure 5 depicts a user controllable input device 60 that can be connected to the heater lifter is via a controller 62 to allow a user to selectively adjust the raised position of the upper heaters 21 a. The user input device 5 60 may take the form of a keyboard, quadrants, buttons, touch screen, hand crank, or other adjustment devices operable by a user. With this a position selection can be implemented using the user input device 60 through which the user selects one of the 10 annealing and curing positions. In a further embodiment, the user's delivery device 60 is operable to allow the user to accurately fine-tune the position of the heater 21 above from the curing position initially set. Different types of continuous materials exhibit different amounts of elasticity so that some will assume a catenary bag more severe than others and will exhibit greater deviations from the catenary path resulting, for example, from disturbances in process line 1 00. Therefore, fine adjustments to the heater lift or displacement amount from the curing position allows the user to place the upper heaters 21 a in the most efficient locations as a function of the type of continuous material being dried and curing in the curing condition of the appliance. That is, the user can selectively place the upper heater 21 a to impart the greatest possible amount of heat to the continuous material 50 while avoiding damaging contact with the web of material. He i -a "** tJteA) * '' * * -» *** "e- ~ -. ± »-.«. «.-.-- - *» - - -. -. - n ^^^ ^ .. controller 62 may also include predetermined fasteners for specific types of materials so that a user can simply feed or select the type of continuous material to be heat treated. In this additional modification, the user can indicate the type of material 50 to be processed and the controller 62 will automatically place the top heaters 21 a in the most efficient curing position based on the type of material. In embodiments having more than one heater 21 to mobile in the first section, the controller 62 can individually and independently control each of the heaters 21 to moveable. The controller 62 may further include a temperature control for adjusting the temperature and the quantity or volume of air flow supplied through the flotation nozzles 26 of the heaters 21 a, 21 b, 22 a, 22 b, 23 a and 23 b. Optionally, each individual section 70, 71, 72 can be controlled separately and each set of heaters within each section can be controlled separately. A temperature sensor 64 having an output connected to a display 66 can also be provided at or near the output end of each section to be controlled in the heating system 20 to monitor the continuous material outlet temperature. In Figure 5, the temperature detector 64 is shown by way of example at the exit end of the third section 72. However, the temperature detector 64 can be placed in any of the sections 70, 71, 72 and can be placed in each of sections 70, 71, 72 to monitor and control temperature separately from each. The display 66 may be mounted as a separate unit or as a part of the delivery device or controller 66. The temperature detector 64 and display 66 allow continuous monitoring of the exit temperature of the material processed by the user so that the The temperature imparted in each section can be adjusted as necessary through the delivery device 60 to maintain a desired temperature. Also feeding the output of the temperature detector 64 to the controller 62, the controller can be used to dynamically and automatically adjust the temperature of the air and the air flow through the flotation nozzles 26 in response to the type of heat treatment and for temperature settings selected by the user fed into the delivery device 60 to maintain a constant material temperature. In this optional improvement, the user can initially set a desired temperature for the desired type of heat treatment; the controller will then tune the temperatures and / or air flow rates of the heaters 21 a, 21 b, 22 a, 22 b, 23 a, 23 b in response to the temperature detector (s) 64 output signal and the temperature settings manually fed through the delivery device 60 to impart the desired processing temperature and characteristics for the continuous material. Although fundamental novel aspects of the present invention applied to a preferred embodiment thereof have been shown and described and pointed out, it will be understood that various omissions and substitutions and changes in the described methods and in the form and details of the illustrated devices may be made. , and in its operation, by those skilled in the art without departing from the spirit of the present invention. For example, it is expressly intended that all combinations of those elements and / or method steps that perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention.

«Invention. Substitutions of elements from one modality described to another are included and contemplated also completely. It should also be understood that the drawings are not necessarily drawn to scale, but are merely conceptual in nature. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended thereto. - tAM-í. ^ l

Claims (18)

1. REVIVALITION IS 1. A convertible heating system for use in a process line for heat treating a web material according to the web material is advanced throughout the heating system, where the process line includes an input section for providing untreated sheet material to the convertible heating system and an outlet section for receiving the treated continuous sheet material of the convertible heating system, said convertible heating system comprising: a housing having an inlet end for receiving the continuous sheet material to be treated with heat and an outlet end and defining a path along which the material is operatively advanced through the housing from the entrance end to the exit end, said housing enclosing a plurality of heating sections arranged serially along the path; a convertible section of said plural heating sections comprising first and second opposedly opposed heaters disposed on opposite sides respectively of said path to direct hot air from said heaters toward opposite faces of the continuous web material as the web material is advanced along the path in said housing, said second heater being fixed in position in said housing and said first heater being movable substantially transverse to said path between a first predetermined position stopping said second heater to apply a first thermal treatment to the material of continuous sheet and a second position farther from the second heater than said predetermined spacing of said first position for applying a second heat treatment to the web material; and a heater lifting device connected to said first heater and selectively operable to move said first heater between said first and second positions of the first heater to convert said heating system between first and second heat treatment configurations to apply said first and second treatments thermal to the continuous sheet material; said second heater comprising means for directing a stream of hot air substantially upwardly over one of the opposite faces of the web material to support the web material in the hot air stream in a substantially horizontal orientation through said section convertible in said first position of the first heater for applying said first heat treatment to the web material, and for directing the stream of hot air substantially upwardly on one of the opposite faces of the web material without supporting the sheet material continues in the hot air stream and thereby allows the sheet material to assume a catenary bag through said adjustable section in said second position of the first heater to apply said second heat treatment to the unsupported web material. The convertible heating system of claim 1, wherein said adjustable section comprises a first of said plural sections disposed serially positioned immediately adjacent said inlet end of the convertible heating system. 3. The convertible heating system of claim 1, wherein said second heater comprises a plurality of flotation nozzles configured to direct hot air from the second heater upwardly to the continuous sheet material to support the sheet material. It continues in the air heated in said substantially horizontal orientation in the first position of the first heater. 4. The convertible heating system of claim 1, wherein said first heat treatment comprises or not annealing, tempering, preheating and normalizing, and said second heat treatment comprises cure. The convertible heating system of claim 1, wherein said inlet end of the housing is configured to introduce the continuous sheet material to the housing at a first distance above said second heater in said first position of said first heater for applying said first heat treatment to the continuous sheet material as the sheet material is advanced along said path, and at a second distance above said second heat and greater than said first distance for applying said second treatment thermal to the web material as the sheet material is advanced along said path, said second distance being sufficient to prevent contact of the second heater with the web material in said catenary bag. The convertible heating system of claim 1, wherein said first heater comprises a plurality of movable heater units, and wherein said heater lifter device is connected to said plural heater units for operatively displacing each said heater unit to a according to a different position so that each said heating unit is stopped differently from the second heater in said second position of the first heater to apply said first heat treatment to the continuous sheet material in said catenary bag. The convertible heating system of claim 6, wherein said separate positions of said heating units are selected such that said heating units are spaced from said second heater to substantially separate the catenary bag from the web material. . 8. The convertible heating system of claim 5, wherein said first heater comprises a plurality of units is movable heaters, and wherein said heater lifting device is connected to said plural heater units to operatively displace each said unit. heater to a second distinct position so that each said heating unit is separated differently from the second heater in said second position of the first heater to apply said first heat treatment to the web material in said catenary bag. 9. The convertible heating system of claim 8, wherein said different positions of a heating element are selected such that said heating units are stopped from said second heater to substantially follow the catenary bag of the material. of continuous sheet. The convertible heating system of claim 1, further comprising a controller having a connected outlet has said heater lifting device and a delivery device operable by a user for user selection of one of the first and second configuring heat treatment rations, said output from the controller responding to said operating device operable by a user to cause said heater lifting device to move said first heater between said first and second positions in response to said output of the heater. controller. eleven . The convertible heating system of claim 1 0, further comprising a temperature detector placed in said housing proximate an outlet end of one of said plural heating sections for detecting or peratively & * - l *. * a * s * j the temperature of the web material proximate the exit end of said one of the plural heating sections, and connected to said controller for use by said controller to cause said heater lift device to adjust accordingly. minus one of the first and second positions of the first heater to effect a predetermined heat treatment of the web material in said housing. 12. The convertible heating system of claim 1, wherein said delivery device operable by a user comprises a temperature selection device operable for selection of the user of a desired temperature of the web material in the container. output end of said one of the plural heating sections, and wherein said controlled! it is operable to automatically adjust a heat output applied to the web material in said one of the plural heating sections in response to the desired temperature selected by a user and the temperature detected by said temperature sensor. 13. The convertible heating system of claim 1, wherein said housing further comprises a barrier disposed separately between adjacent ones of said plural heating sections to allow maintenance of desired temperature differentials between adjacent heating sections. separated by said barrier 14. The convertible heating system of claim 1, wherein the process line further includes a coater between said inlet section and said convertible heating system for applying a coating to the continuous sheet material before that the sheet material enters the heating system for application of the second heat treatment to the web material in said housing, and wherein said entry end of the housing is configured to introduce the web material to the housing at a first distance above said second lime In said first position of said first heater and when the web material is diverted from the coater to apply said first heat treatment to the web material as the web material is advanced along said path, and said end The housing inlet is configured to insert the web material into the housing from the coater at a second distance above said second heater and greater than said first distance to apply said second heat treatment to the continuous sheet material in accordance with The sheet material is advanced along said path, said second distance being sufficient to prevent contact of the second calender with the continuous sheet material in said catenary bag. The convertible heating system of claim 1, wherein said plural heating sections further comprise a fixed heating section which serially follows said convertible section and which has a heating set on its upper side. bottoms facing each other on opposite sides respectively of said path to direct hot air from said upper heaters & JÉ & 4% ¿iie £ káS & &st < ? & 2 £ «- ^ * ¿¿^« s. . j ^ .., ^. ^. A ^ - ¿.j »Aitf A» ffi. t-. ^ »A..A. . *. ,. The lower end faces the opposite faces of the web material as the continuous web material is advanced along the path in said fixed heating section, and a cooling section following said web section. fixed heating to cool the web material as the web material is advanced along the path in said cooling section by directing air towards the opposite faces of the web material in said cooling section. 16. The convertible heating system of claim 1 5, wherein predetermined heated air is directed towards the opposite faces of the web material in said cooling section. 17. The convertible heating system of claim 1, wherein unheated ambient air is directed toward the opposite sides of the web material in said cooling section. 18. The convertible heating system of claim 1, wherein said housing further comprises a barrier disposed separately between adjacent ones of said plu- ral heating sections to allow the maintenance of desired temperature differentials between the adjacent heating sections separated by said barrier.