Patent Abstract:
An electric glass hot shop system is described herein that has at least one electrically powered heating unit (e.g., electric furnace, electric glory hole, electric pipe warmer, electric color box, electric annealer, electric crucible kiln) used in the processing of glass.

Full Description:
CLAIMING BENEFIT OF PRIOR FILED U.S. APPLICATION 
       [0001]    This is a continuation of U.S. patent application Ser. No. 12/603,167 entitled “Electric Glass Hot Shop System” filed on Oct. 21, 2009, now pending, the content of which is relied upon and incorporated herein by reference in its entirety. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to an electric glass hot shop system that has at least one electrically powered heating unit (e.g., electric furnace, electric glory hole, electric pipe warmer, electric color box, electric annealer, electric crucible kiln) used in the processing of glass. 
       BACKGROUND 
       [0003]    Extremely high temperatures are required to enable the melting, processing and forming of glass. In typical glass forming operations this high temperature requirement extends to the initial melting of the glass in a furnace, the periodic re-heating of the glass in a glory hole, the heating of the glass while applying colored additives in a color box, the pre-heating of a glass manipulating pipe in a pipe warmer, and the annealing of formed glass in an annealer. Generally, glass working equipment uses natural gas or propane fueled flames as heat sources to melt, process and form the glass. However, there are some situations or venues where a gas source is not readily available, or where the use of a gas source is excluded for safety reasons. For instance, one such situation or venue where a gas source is prohibited for safety reasons is on a cruise ship where it would be desirable to be able to perform hot glass forming shows for people vacationing on the cruise ship. 
         [0004]    In these situations or venues, electrically heated glass working equipment are alternatives to the glass working equipment that use a gas source. The electrically heated glass working equipment utilize electrically resistive heating elements such as, for example, molybdenum disilicide to generate radiative heat. Unfortunately, electricity is typically a poor means of supplying bulk energy to glass working equipment. For instance, a typical glass furnace of about 150 lbs capacity would have to be supplied with a 400,000 BTU burner, which is the equivalent of approximately 115 KW of electrical power. However, 115 KW power supplies are generally much too expensive and bulky to be considered as a useful source of energy for such a small glass furnace. In contrast, power supplies of &lt;35 KW are economically feasible and can be a useful source of energy for a glass furnace if a more efficient insulation package is provided and the glass is allowed a longer period of time to melt and fine out. There are several types of electrically heated glass furnaces currently available today on the market, which use low energy inputs, but they have their own problems and they often introduce design features that limit their usefulness. These problems and other problems associated with other types of glass working equipment are discussed below. 
         [0005]    Furnace
       Existing door systems have tracks and wheels which fail to create a tight seal and are prone to energy leakage. Furthermore, existing rear hinge designs eliminate easy access to heating elements in the top of the furnace   The heating elements are mounted in the top (crown) of the furnace, which means that the heating elements and corresponding electrical supplies must be removed to be able to access and service the crucible.       
 
         [0008]    Glory hole (GH)
       Existing door systems are difficult to maintain and have undesirable energy leakage.   There are few electric glory hole&#39;s commercially available. Perhaps one reason for this is that heating elements are located in a position that creates a potential for contact with glass which if this occurred it would render the heating elements useless. Another possible reason is that electric heat elements provide mostly radiant heat with very little convection energy like gas fired glory holes and as a result there would be undesirable hot spots in the walls next to the heating element holders.       
 
         [0011]    Combination pipe warmer and color box
       There are no electrically heated pipe warmers commercially available.       
 
         [0013]    Annealer
       Existing annealer door seals fail due to their exposure to heat and abrasion during the loading and unloading of the annealer.       
 
         [0015]    Annealer&#39;s Crucible Kiln
       Existing door is too large and when it is opened to much heat escapes.       
 
         [0017]    Thus, any enhancement of the traditional glass working equipment and in particular the electrical glass working equipment would help improve the melting, processing and forming of glass. 
       SUMMARY 
       [0018]    In one aspect, the present invention provides an electric glass hot shop system for processing glass that includes: (a) an electric furnace; (b) an electric glory hole; (c) an electric pipe warmer; (d) an electric color box; (e) an electric annealer; and (f) an electric crucible kiln. The electric glass hot shop system is well suited to be used in a venue or situation where a gas source is prohibited to be used for safety reasons like on a cruise ship. 
         [0019]    In another aspect, the present invention provides an electric glory hole for processing glass. In one example, the electric glory hole includes: (a) a body with a first opening located therein; and (b) a door system including a first door which is hung over the first opening in the body, where the first door has a first hinged side and a second hinged side, where the first hinged side has a first frame that receives and supports at least one cast block, and where the second hinged side has a second frame that receives and supports at least one cast block. The door system may further include: (a) a second door which has a first hinged side and a second hinged side, where the first hinged side has a first frame that receives and supports at least one cast block, and where the second hinged side has a second frame that receives and supports at least one cast block; (b) a third door which has a first hinged side and a second hinged side, where the first hinged side has a first frame that receives and supports at least one cast block, and where the second hinged side has a second frame that receives and supports at least one cast block; and (c) the first door is hung over the first opening on the body, and the second door is hung on the first door, and the third door is hung on the second door. The electric glory hole may also include a specially designed refractory element baffle which is located within the body, where each refractory element baffle includes a block with a passage through which an heating element is inserted and a cavity in which hangs the heating element, where the cavity is larger than the heating element, and where the cavity is sized to encompass at least three sides of the heating element. Furthermore, the electric glory hole may have one or more specially designed insulation packages which help to maintain a desired temperature within the body. 
         [0020]    In yet another aspect, the present invention provides an electric furnace for processing glass. In one example, the electric furnace includes: (a) a crucible unit; and (b) a heating unit, coupled to the crucible unit, where the heating unit has an opening formed therein and a door attached to a cantilevered arm which has a hinge connected to at least an outer portion of the heating unit, where the cantilevered arm rotates on the hinge such that the door is moved to cover the opening and prevent access to an interior of the heating unit and the crucible or the door is moved away from the opening to allow access to the interior of the heating unit and the crucible. The heating unit may further include a crown suspension system located therein which supports at least one heating element, where the crown suspension system includes a ring of locking bricks that support a crown casting which then supports the at least one heating element. Furthermore, the electric furnace may have one or more specially designed insulation packages which help to maintain a desired temperature within the crucible and the heating unit. 
         [0021]    Additional aspects of the invention will be set forth, in part, in the detailed description, figures and any claims which follow, and in part will be derived from the detailed description, or can be learned by practice of the invention. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as disclosed. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    A more complete understanding of the present invention may be had by reference to the following detailed description when taken in conjunction with the accompanying drawings wherein: 
           [0023]      FIG. 1  is a block diagram of an exemplary electric glass hot shop system which includes an electric furnace, an electric glory hole, an electric pipe warmer, an electric color box, an electric annealer, and an electric crucible kiln in accordance with an embodiment of the present invention; 
           [0024]      FIGS. 2A-2G  are different diagrams illustrating in greater detail the exemplary electric furnace shown in  FIG. 1  in accordance with an embodiment of the present invention; 
           [0025]      FIGS. 3A-3M  are different diagrams illustrating in greater detail the exemplary electric glory hole shown in  FIG. 1  in accordance with an embodiment of the present invention; 
           [0026]      FIGS. 4A-4B  are different diagrams illustrating in greater detail the exemplary electric pipe warmer and the exemplary electric color box shown in  FIG. 1  in accordance with an embodiment of the present invention; 
           [0027]      FIGS. 5A-5G  are different diagrams illustrating in greater detail the exemplary electric annealer shown in  FIG. 1  in accordance with an embodiment of the present invention; and 
           [0028]      FIGS. 6A-6D  are different diagrams illustrating in greater detail the exemplary electric crucible kiln shown in  FIG. 1  in accordance with an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0029]    Referring to  FIG. 1 , there is shown a block diagram of an exemplary electric glass hot shop system  100  in accordance with an embodiment of the present invention. In this example, the electric glass hot shop system  100  includes an electric furnace  102 , an electric glory hole  104 , an electric pipe warmer  106 , an electric color box  108 , an electric annealer  110 , and an electric crucible kiln  112 . The electric glass hot shop system  100  further includes a power supply  114  (e.g., &lt;35 KW power supply  114 ) that supplies electricity to the electric furnace  102 , the electric glory hole  104 , the electric pipe warmer  106 , the electric color box  108 , the electric annealer  110 , and the electric crucible kiln  112 . Typically, the electric furnace  102  is used to melt batch materials to form a molten glass. The electric glory hole  104  is used to periodically re-heat the molten glass while a pipe is used to hold and manipulate the molten glass to form the desired glass shape. The electric pipe warmer  106  is used to pre-heat the pipe. The electric color box  108  is used to apply colored additives to the molten glass during the forming process. The electric annealer  110  is used to anneal the formed glass. The electric crucible kiln  112  which is placed under the electric annealer  110  is used to melt small quantities of glass and colored fits, usually less then 50 lbs. Each piece of electric glass working equipment  102 ,  104 ,  106 ,  108 ,  110  and  112  is considered to be an individual component that can stand and function alone rather than having to be part of the entire electric glass hot shop system  100 . Each electric glass working equipment  102 ,  104 ,  106 ,  108 ,  110  and  112  is discussed and described in greater detail below with respect to  FIGS. 2-6 . 
         [0030]    Referring to  FIGS. 2A-2G , there are different diagrams illustrating in greater detail the exemplary electric furnace  102  in accordance with an embodiment of the present invention. The electric furnace  102  includes a crucible unit  202 , a heating unit  204 , and an electrical control box  206  (see  FIGS. 2A-2B ). The crucible unit  202  is where the batch materials are placed and then melted to form the molten glass (not shown). The crucible unit  202  is attached to the heating unit  204  in a manner that makes it easy to drop and move the crucible unit  202  out of the way when one needs to perform maintenance on the heating unit  204 . Also, the crucible unit  202  can be easily dropped and removed from the heating unit  204  so a new crucible unit  202  can be quickly connected to the heating unit  204 . The electrical control box  206  supplies the required electricity to one or more heating elements  208  which are located within the heating unit  204 . The electric furnace  102  includes other components but only the components like a crown suspension system  210 , a torsion-box door system  212 , and specially designed insulation packages  214   a ,  214   b  and  214   c  which are relevant to the present discussion are described in detail below. 
         [0031]    As shown in  FIG. 2B , the heating unit  204  incorporates the crown suspension system  210  which has a crown  216  that supports the heating elements  208  in a manner that allows the crucible unit  202  to be serviced without having to remove the crucible unit  202  from the heating unit  204 . The crown suspension system  210  includes a cast tube  218  (outer body of furnace  102 ) which has a rabbit  220  on the bottom edge thereof is configured to receive a ring of locking bricks  222 . The locking bricks  222  are arranged between the cast tube  218  and a crown casting  224 . The locking bricks  222  prevent the crown  216  (which is supported by the crown casting  224 ) from falling down and also transfer the weight of the crown casting  224  to a lower outside ring  226  on the heating unit  204 . The ring of locking bricks  222  is suspended and cantilevered in a way that leaves a clear space under the crown  216  to provide access to the crucible unit  102 . The crown suspension system  210  greatly reduces the amount of down time required to change the crucible unit  102  and eliminates need for removing electrical components during service. 
         [0032]    As shown in  FIGS. 2A-2D , the heating unit  204  includes the torsion box door system  212  which has a door  228  attached to a cantilevered arm  230  in a manner that allows the door  228  to be adjusted in-and-out, up-and-down, as well as sideways. The cantilevered arm  230  has a hinge  232  which is connected to a body  234  of the heating unit  204 . The cantilevered arm  230  rotates on the hinge  232  over a central axis to allow the door  228  to be moved to cover an opening in the heating unit  204  or to allow the door  228  to be moved away from the opening in the heating unit  204 . The door system  212  makes it easy to change the crucible unit  202  and allow unobstructed access to the heating elements  208 . The door system  212  is a marked-improvement over the traditional door systems that utilize tracks and wheels which fail to create a tight seal and are prone to energy leakage. Plus, the door system  212  is a marked-improvement over the traditional rear-hinge door systems which prevent easy access to the heating elements  208  located in the top of the furnace unit  204 . 
         [0033]    As shown in FIGS.  2 B and  2 E- 2 G, the crucible unit  202  and the heating element  204  incorporate specially designed insulation packages  214   a ,  214   b  and  214   c  that help to prevent the interior of the electric furnace  102  from becoming too cold or too hot during the melting operation. In this example, the electric furnace  102  would normally have an internal operating temperature in a range of about 1120° C. to 1250° C. In  FIG. 2E , the crucible unit  202  is shown to have a furnace crucible floor  236  which is made from an outer panel  238  and a specially designed insulation package  214   a . In this example, the specially designed insulation package  214   a  includes a microporus panel  240  (approximately 1″ thick) located next to the outer panel  238 , a fire brick  242  (approximately 2½″ thick) located next to the microporus panel  240 , a low cement castable layer  244  (e.g., 1½″ thick intracast MZ  244 ) located next to the fire brick  242 , and a crucible material  246  (e.g., 1½″ thick cast mullite  246 ) located next to the low cement castable layer  244 . The crucible material  246  has an outer face  248  which is exposed to the heat. 
         [0034]    In  FIG. 2F , the crucible unit  202  is shown to have a furnace crucible wall  250  which is made from an outer panel  252  and a specially designed insulation package  214   b . In this example, the specially designed insulation package  214   b  includes a microporus panel  254  (approximately ½″ thick) located next to the outer panel  252 , a ceramic fiber layer  256  (e.g., 1½″ thick HP fiber frax  256 ) located next to the microporus panel  254 , a fire brick  258  (approximately 2½″ thick) located next the ceramic fiber layer  256 , a low cement castable layer  260  (e.g., 2″ thick intracast MZ  260 ) located next to the fire brick  258 , and a crucible material  262  (e.g., 2″ thick cast mullite  262 ) located next to the low cement castable layer  260 . The crucible material  262  has an outer face  264  which is exposed to the heat. 
         [0035]    In  FIG. 2G , the heating unit  204  is shown to have a furnace crown wall  266  which is made from an outer panel  268  and a specially designed insulation package  214   c . In this example, the specially designed insulation package  214   c  includes a microporus panel  270  (approximately ½″ thick) located next to the outer panel  268 , a ceramic fiber layer  272  (e.g., 3″ thick HP fiber frax  272 ) located next to the microporus panel  270 , and a low cement castable layer  274  (e.g., 2½″ thick intracast MZ  274 ) located next to the ceramic fiber layer  272 . The low cement castable layer  274  has an outer face  276  which is exposed to the heat. 
         [0036]    Referring to  FIGS. 3A-3M , there are several different diagrams illustrating in greater detail the exemplary electric glory hole  104  in accordance with an embodiment of the present invention. The electric glory hole  104  is mounted on a structure  301  and includes a body  302  with an opening  304  through which a pipe holding molten glass can be inserted and then manipulated to form the desired glass shape (see  FIGS. 3A-3D ). The electric glory hole  104  includes an electrical control box  306  which supplies the required electricity to one or more heating elements  308  (see  FIGS. 3A-3D ). The electric glory hole  104  includes other components but only the components like a specially designed door system  310 , specially designed refractory element baffles  312 , a video camera  314  and specially designed insulation packages  316   a ,  316   b  and  316   c  which are relevant to the present discussion are described in detail below. 
         [0037]    As shown in  FIGS. 3A-3F , the electric glory hole  104  includes the specially designed door system  310  which has three doors  318 ,  320  and  322  where the first door  318  is hung upon the body  302  and at least partially covers the opening  304 , the second door  320  is hung upon the first door  318 , and the third door  322  is hung upon the second door  320 . The first door  318  is larger than the second door  320  which in turn is larger than the third door  322 . In this example, the first door  318  has a first hinged side  324   a  and a second hinged side  324   b , where the first hinged side  324   a  has a first frame  326   a  that receives and supports one or more cast blocks  328   a  and  328   a ′ (two shown) and the second hinged side  324   b  has a second frame  326   b  that receives and supports one or more cast blocks  328   b  and  328   b ′ (two shown) (see  FIGS. 3E-3F ). The second door  320  has a first hinged side  330   a  and a second hinged side  330   b , where the first hinged side  330   a  has a first frame  332   a  that receives and supports one or more cast blocks  334   a  and  334   a ′ (two shown) and the second hinged side  330   b  has a second frame  332   b  that receives and supports one or more cast blocks  334   b  and  334   b ′. Likewise, the third door  322  has a first hinged side  336   a  and a second hinged side  336   b , where the first hinged side  336   a  has a first frame  338   a  that receives and supports one or more cast blocks  340   a  and  340   a ′ (two shown) and the second hinged side  336   b  has a second frame  338   b  that receives and supports one or more cast blocks  340   b  and  340   b′.    
         [0038]    The doors  318 ,  320  and  322  can be easily kept in optimal condition and thus allow minimal energy loss since if any of the cast blocks  328   a ,  328   a ′,  328   b ,  328   b ′,  334   a ,  334   a ′,  334   b ,  334   b ′,  340   a ,  340   a ′,  340   b  and  340   b ′ have to be replaced then all one needs to do is remove the damaged cast block from the frame  324   a ,  324   b ,  332   a ,  332   b ,  338   a  and  338   b  and insert the new cast block. For instance, if the first door  318  had a damaged cast block  328   a ′ then one would remove pins  342   a  and  342   b  from the first frame  326   a  and slide-out the damaged cast block  328   a ′ (see  FIGS. 3E and 3F ). Then, the new cast block  328   a ′ can be placed in the first frame  326   a  and the pins  342   a  and  342   b  re-inserted to hold the new cast block  328   a′.    
         [0039]    As shown in  FIGS. 3B-3C  and  3 G, the electric glory hole  104  has a core  344  which is sized and configured to enable a pipe holding molten glass to be inserted therein through the opening  304 . The core  344  is formed from interconnected fire bricks  346  and a series of refractory element baffles  312 . In  FIG. 3H , there is shown a perspective view of exemplary refractory element baffle  312  that includes a block  350  which has a passage  352  located in a top thereof and a cavity  354  formed in a side thereof. The passage  352  is sized to receive a heating element  308  (e.g., molybdenum discilicide heating element  308 ) which is inserted at least partially there through and the cavity  354  is sized to encompass and protect at least three sides of the heating element  308  (see  FIGS. 3B-3C ). In particular, the refractory element baffle  312  has sides  358  which protect the heating element  308  located and hanging within the cavity  354  such that when the pipe is inserted within the core  344  it will not be able to touch and damage the heating element  308 . Plus, the refractory element baffle  312  with the specially shaped cavity  354  creates a high temperature shell around the heating element  308  that reflects energy into the core  344 . In one embodiment, the refractory element baffle  312  is cast from a 3000° F. dense refractory and the cavity  354  where the heating element  308  hangs is approximately ½″ larger than the heating element  308 . Plus, the heating element  308  when installed is recessed about 1 inch from the inner edges of the cavity  354 . The refractory element baffle  312  solves the problem of having the heating element  308  to close to the pipe and helps to reduce the potential damage to the heating element  308  as well as reduce the potential hazard due to an electric shock and short circuit. 
         [0040]    As shown in  FIGS. 3B-3C  and  3 I- 3 J, the electric glory hole  104  has a video camera  314  attached thereto so that it is isolated from the heat inside the core  344 . The video camera  314  is used to demonstrate what takes place inside the core  344  when the molten glass is re-heated on the pipe. In this example, the video camera  314  connects to one side  367  of a lens holder  362  which has another side  369  attached to a camera casting  360  (see  FIGS. 3I and 3J ). The camera casting  360  is a cast refractory block that is located within an opening  364  in the body  302 . The camera casting  360  has a tapered opening  366  in communication with the core  344 , where the tapered opening  366  is sized to allow adequate visual inspection of the glory hole interior from behind the back wall of the body  302 . The lens holder  362  includes a heat block seal  368  that has a groove  370  which holds a lens  372  (e.g., 2″×2″ high temperature quartz lens  372 ) followed by an air purge gap  374  (which is supplied gas from a gas purge system  376 ) which is followed by another groove  378  within which is placed a glass filter lens  380 . The quartz lens  372  (located next to the video camera  314 ) prevents hot corrosive gases located inside the core  344  from attacking the video camera  314 . The glass filter lens  380  (located next to the camera casting  360 ) shields the video camera  314  from heat transferred from the lens  372 . In one example, the video camera  358  would be mounted within 1″ of the glass filter lens  380 . 
         [0041]    As shown in  FIGS. 3B-3C  and  3 K- 3 M, the electric glory hole  104  incorporates specially designed insulation packages  316   a ,  316   b  and  316   c  that help limit the temperature of the outer shell  382  to be less than 225° F. In  FIG. 3K , the electric glory hole  102  is shown to have a glory hole element block wall  383  which is made from an outer panel  384  and a specially designed insulation package  316   a . In this example, the specially designed insulation package  316   a  includes a microporus panel  385  (approximately 1″ thick) located next to the outer panel  384 , a ceramic fiber layer  386  (e.g., 2″ thick HP fiber frax  386 ) located next to the microporus panel  385 , a low cement castable layer  387  (e.g., 2″ thick intracast MZ  387 ) located next to the ceramic fiber layer  386 . The low cement castable layer  387  has an outer face  388  which is exposed to the heat. 
         [0042]    In  FIG. 3L , electric glory hole  102  is shown to have a glory hole wall  389  which is made from an outer panel  390  and a specially designed insulation package  316   b . In this example, the specially designed insulation package  316   b  includes a microporus panel  391  (approximately ½″ thick) located next to the outer panel  390 , a ceramic fiber layer  392  (e.g., 1½″ thick HP fiber frax  392 ) located next to the microporus panel  391 , a fire brick  393  (approximately 2½″ thick) located next the ceramic fiber layer  392 . The fire brick  393  has an outer face  394  which is exposed to the heat. 
         [0043]    In  FIG. 3M , electric glory hole  102  is shown to have a glory hole back wall  395  which is made from an outer panel  396  and a specially designed insulation package  316   c . In this example, the specially designed insulation package  316   c  includes a microporus panel  397  (approximately ½″ thick) located next to the outer panel  396 , a ceramic fiber layer  398  (e.g., 2½″ thick HP fiber frax  398 ) located next to the microporus panel  397 , a fire brick  399  (approximately 2½″ thick) located next the ceramic fiber layer  398 . The fire brick  399  has an outer face  381  which is exposed to the heat. 
         [0044]    Referring to  FIGS. 4A-4B , there are several diagrams illustrating in greater detail the exemplary electric pipe warmer  106  and the exemplary electric color box  108  in accordance with an embodiment of the present invention. The electric pipe warmer  106  is used to pre-heat the pipe which is used to hold and manipulate the molten glass during the forming process. The electric color box  108  is used to apply colored additives to the molten glass during the forming process. In this example, the electric pipe warmer  106  and the electric color box  108  are both mounted on the same support unit  402  and are both supplied electricity from one electrical control box  404 . The electric pipe warmer  106  includes a body  406  with a pipe opening  408  formed therein and one or more heating elements  410  located therein. The pipe opening  408  is sized and positioned such that when a pipe is inserted therein the pipe will not be able to contact the heating elements  410 . In this example, the pipe opening  408  is located near the bottom of the body  406  and the heating elements  410  are attached to the roof of the body  406 . The heating elements  410  are attached to the roof because glass sheds that fall off the pipe during the heating process would damage the heating elements  410  if they where located near the bottom or sides of the body  406 . The heating elements  410  can be nichrome elements which run through protective quartz tubes  412 . The nichrome heating elements  410  can radiate at 2000° F. The electric pipe warmer  106  also includes a specially designed insulation package  414  which includes fire bricks  416  (e.g., 2300° F. fire bricks  416 ) which are coated with a high emissivity coating  418  that is exposed to the heat and helps to increase the heat transfer into cold pipes. The fire bricks  416  are located next to a ceramic fiber  420  (e.g., 1″ thick ceramic fiber  420 ) which is coating the internal portion of the body  406 . 
         [0045]    Referring to  FIGS. 5A-5G , there are several diagrams illustrating in greater detail the exemplary electric annealer  110  in accordance with an embodiment of the present invention. The electric annealer  110  is used to anneal the formed glass. In this example, the electric annealer  110  is mounted on a support unit  502  and is supplied electricity from an electrical control box  504 . The electric annealer  110  includes a body  506  with an opening  508  formed therein which has a door system  510  attached thereto which when opened provides access to the interior of the body  506  and when closed prevents access to the interior of the body  506 . The door system  510  includes a door  512 , a frame  514 , a gasket  516  and a keeper  518 , where the door  512  is attached to the frame  514  which is attached to the gasket  516  which is attached to the keeper  518  which is attached to the body  506  (see  FIG. 5C ). The configuration of the door system  510  is desirable since the gasket  516  (e.g., tadpole silica gasket  516 ) is kept cool and has minimal exposure to abrasion because it is positioned between the frame  514  and the keeper  518 . In addition, the electric annealer  110  has one or more electrical heating elements  520  located in the body  506  which radiate heat to anneal the formed glass. 
         [0046]    As shown in FIGS.  5 B and  5 D- 5 G, the electric annealer  110  also incorporates specially designed insulation packages  522   a ,  522   b ,  522   c  and  522   d . In  FIG. 5D , the electric annealer  110  has an annealer wall  524  which is made from an outer panel  526  and the specially designed insulation package  522   a . In this example, the specially designed insulation package  522   a  includes a ceramic fiber layer  528  (e.g., 1″ thick HP fiber frax  528 ) located next to the outer panel  526 , and a fire brick  530  (approximately 2½″ thick) located next to the ceramic fiber layer  528 . The fire brick  530  has an outer face  532  which is exposed to the heat. 
         [0047]    In  FIG. 5E , the electric annealer  110  has a floor  534  which is made from an outer panel  536  and the specially designed insulation package  522   b . In this example, the specially designed insulation package  522   b  includes a fiberglass silicate layer  538  (e.g., 2″ thick insblock 19  538 ) located next to the outer panel  536 , and a fire brick  540  (approximately 2½″ thick) located next to the fiberglass silicate layer  538 . The fire brick  540  has an outer face  542  which is exposed to the heat. 
         [0048]    In  FIG. 5F , the electric annealer  110  has a ceiling  544  which is made from an outer panel  546  and the specially designed insulation package  522   c . In this example, the specially designed insulation package  522   c  includes a microporus panel  548  (approximately ½″ thick) located next to the outer panel  546 , a ceramic fiber layer  550  (e.g., 2″ thick HP fiber frax  550 ) located next to the microporus panel  548 , and a thermal ceramic layer  552  (e.g., 2″ thick M board  552 ) located next to the ceramic fiber layer  550 . The thermal ceramic layer  552  has an outer face  554  which is exposed to the heat. 
         [0049]    In  FIG. 5G , the electric annealer  110  has the door  512  which is made from an outer panel  556  and the specially designed insulation package  522   d . In this example, the specially designed insulation package  522   d  includes a microporus panel  558  (approximately ½″ thick) located next to the outer panel  556 , a ceramic fiber layer  560  (e.g., 2″ thick HP fiber frax  560 ) located next to the microporus panel  558 , and an thermal ceramic layer  562  (e.g., 2″ thick M board  562 ) located next to the ceramic fiber layer  560 . The thermal ceramic layer  562  has an outer face  564  which is exposed to the heat. 
         [0050]    Referring to  FIGS. 6A-6D , there are several diagrams illustrating in greater detail the exemplary electric crucible kiln  112  in accordance with an embodiment of the present invention. The electric crucible kiln  112  is located below the electric annealer  110  and is used to melt small quantities of glass and colored frits, usually less than 50 lbs. In this example, the electric crucible kiln  112  includes a crucible  602 , a door system  604  and an electrical control box  606  which supplies electricity to heating elements (not shown) located in the crucible  602 . The door system  604  includes a door  608  which is attached to a support arm  610  which has a hinge  612  connected to the crucible  602 . The support arm  610  is arranged to rotate on the hinge  612  such that the door  608  can be moved to cover an opening in the crucible  602  or the door  608  can be moved away from the opening in the crucible  602 . Alternatively, the door system  604  if desired may be mounted on a side of the crucible  602  rather than on top of the crucible  602  (as shown). 
         [0051]    As shown in  FIGS. 6B-6D , the crucible  602  also incorporates specially designed insulation packages  614   a ,  614   b , and  614   c . In  FIG. 6B , the crucible  602  has walls  616  which are made from an outer panel  618  and the specially designed insulation package  614   a . In this example, the specially designed insulation package  614   a  includes a microporus panel  620  (approximately 1″ thick) located next to the outer panel  618 , a ceramic fiber layer  622  (e.g., 1½″ thick HP fiber frax  622 ) located next to the microporus panel  620 , a fire brick  624  (approximately 2½″ thick) located next the ceramic fiber layer  622 . The fire brick  624  has an outer face  626  which is exposed to the heat. 
         [0052]    In  FIG. 6C , the crucible  602  has a ceiling  628  which is made from an outer panel  630  and the specially designed insulation package  614   b . In this example, the specially designed insulation package  614   b  includes a microporus panel  632  (approximately 1″ thick) located next to the outer panel  630 , a ceramic fiber layer  634  (e.g., 1½″ thick HP fiber frax  634 ) located next to the microporus panel  632 , a fire brick  636  (approximately 2½″ thick) located next the ceramic fiber layer  634 . The fire brick  636  has an outer face  637  which is exposed to the heat. 
         [0053]    In  FIG. 6D , the crucible  602  has a floor  638  which is made from an outer panel  640  and the specially designed insulation package  614   c . In this example, the specially designed insulation package  614   c  includes a microporus panel  642  (approximately 1½″ thick) located next to the outer panel  640 , a fire brick  644  (approximately 2½″ thick) located next the microporus panel  642 , a fiberglass silicate layer  646  (e.g., 1½″ thick insblock 19  646 ) located next to the fire brick  644 . The fiberglass silicate layer  646  has an outer face  648  which is exposed to the heat. 
         [0054]    Although one embodiment of the present invention has been illustrated in the accompanying Drawings and described in the foregoing Detailed Description, it should be understood that the invention is not limited to the disclosed embodiment, but is capable of numerous rearrangements, modifications and substitutions without departing from the spirit of the invention as set forth and defined by the following claims.

Technology Classification (CPC): 2