Patent Description:
In the manufacturing process for making glass, raw materials including sand, lime, soda ash and other ingredients are fed into a furnace, sometimes called a glass tank. The raw materials are subjected to temperature above about <NUM>,<NUM>°F in the glass furnace which causes the raw materials to melt and thereby form a molten bed of glass that exits the glass furnace for further downstream processing into glass products.

The most common way of heating the glass furnace is through the combustion of a hydrocarbon fuel source, such as natural gas or oil. The hydrocarbon fuel is mixed with combustion air inside the furnace and combusted to thereby transfer the combustion heat energy to the raw materials and glass melt prior to exiting the furnace.

In order to improve the thermal efficiency of the combustion process, the combustion air used to combust the fuel is preheated by means of regenerator structures. More specifically, a supply of combustion air is preheated in a honeycombed pack of checker bricks contained within the interior of the regenerator structure. Fresh combustion air is drawn up through the pack of heated checker bricks in the regenerator structure and preheated by means of heat transfer. The pre-heated combustion air may then be mixed with the fuel, combusted. Waste combustion gas exits the glass furnace and passes through a second regenerator structure. As the waste gasses pass through the second regenerator the checkers in the pack are heated by means of heat transferred from the waste gas. After a predetermined time has elapsed (e.g., after about <NUM>-<NUM> minutes), the process cycle is reversed so that the checker bricks in one of the regenerator structures that were being heated by heat transfer with the waste gas are then used to preheat the fresh combustion air while the checker bricks in the other regenerator structures that were used to preheat the combustion air are then re-heated by heat transfer with the waste combustion gas. See in this regard, <CIT>.

The current process for building glass furnace refractory structures, e.g., regenerators, glass furnaces, fore hearths and the like, is very labor intensive taking many weeks as it requires the placement of hundreds of thousands of refractory bricks that may be individually coated with mortar and positioned or in some cases essentially dry set with minimal (if any) mortar. As is well known in the glass making industry, the joints associated with the bricks of the furnace refractory structures are the weakest part of the structure and are consequently more readily susceptible to degradation by the corrosive hot gasses passing therethrough. As the brick joints begin to erode, the walls forming the refractory structure face increased attack as the corrosive gasses begin to condense and dissolve the refractory materials forming the bricks thereby weakening the structure. As the structure becomes weakened, the glass furnace itself may become compromised and fail which could then require a complete shut down and rebuilding operation. <CIT> describes the rebuilding of a coke oven.

It can be appreciated therefore, that if the refractory structures could be fabricated from larger refractory blocks, then fewer joints would ensue thereby prolonging the regenerator structure's useful life and minimizing down time due to rebuilding. However, while large refractory blocks can be fabricated by pressing, molding or casting a refractory material, it is problematic to install such blocks during construction of a large-scale refractory structure.

In addition to the problems noted above, many of the components of the refractory structure, e.g., checker bricks used in glass regenerator structures, need to be replaced near or at the end of their useful life in order to maintain optimal production efficiencies. It is currently difficult to replace such components, e.g., the checker bricks, when it may be desired for them to do so.

What has been needed therefore are improvements in apparatus and methods whereby refractory structures may be efficiently and economically constructed and/or re-built. It is towards providing such improvements that the embodiments of the present invention are directed.

In general, the embodiments disclosed herein are directed toward methods and apparatus for constructing a refractory structures, e.g., glass furnace regenerators, glass furnace systems such as glass furnace refiners, and the like having walls formed of refractory block and buck stays externally supporting the walls. According to the invention, an apparatus according to claim <NUM> is provided.

According to other embodiments, a method for constructing a regenerator structure according to claim <NUM> is provided.

These and other aspects and advantages of the present invention will become more clear after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.

The disclosed embodiments of the present invention will be better and more completely understood by referring to the following detailed description of exemplary non-limiting illustrative embodiments in conjunction with the drawings of which:.

Accompanying <FIG> schematically depicts a perspective view of a regenerator structure <NUM> showing an overhead crane apparatus <NUM> in accordance with an embodiment of the present invention. As shown, the regenerator structure <NUM> is constructed of large pre-cast refractor blocks (a few of which are identified by reference numeral <NUM>) stacked on a foundation <NUM> to thereby form side and end walls <NUM>, <NUM>, respectively. It will be appreciated that the regenerator structure <NUM> is used in operative combination with a glass furnace (not shown). The regenerator structure <NUM> generally depicted in the accompanying figures is of a type used for side-fired glass furnaces. However, the attributes of the embodiments of the invention to be described herein are equally applicable to other glass furnace designs, e.g. end-fired glass furnaces.

The regenerator structure <NUM> includes a series of ports <NUM>-<NUM> which are used to introduce pre-heated combustion air into the glass furnace (not shown) or to exhaust combustion gas from the furnace depending on the operational cycle. The top of the regenerator structure <NUM> is capped with crowns (a representative few of which are noted by reference numeral <NUM>-<NUM>). An operator platform <NUM>-<NUM> typically is provided near the ports <NUM>-<NUM>. The walls <NUM>, <NUM> are structurally supported by external upright structural beams known colloquially as buck stays <NUM>. As is shown in <FIG> and <FIG>, the buck stays <NUM> are compressively held against the walls by means of tie rods <NUM> extending between opposed pairs of buck stays <NUM> both latitudinally and longitudinally relative to the regenerator structure <NUM>.

<FIG> depicts a state whereby the walls <NUM>, <NUM> have been constructed of relatively large monolithic refractory blocks <NUM> and the checker bricks (a supply of which stacked on the platform <NUM>-<NUM> is denoted in <FIG> by reference numeral <NUM>) are being stacked within the interior space of the regenerator structure <NUM>. The apparatus <NUM> in the state shown in <FIG> has thus been employed to install the refractory blocks <NUM> when forming the walls <NUM>, <NUM> and is thereby in the process of installing the checker bricks <NUM> within the interior defined by such walls <NUM>, <NUM>. For this reason, a few of the crowns <NUM>-<NUM> have not yet been installed at one end of the regenerator structure <NUM> so as to permit access into its interior space.

The overhead crane apparatus <NUM> in accordance with the invention is depicted as including laterally spaced-apart upright pairs of upright support beams <NUM> and a cross-support beam <NUM> spanning the distance therebetween. A foundation beam <NUM> extends between and is rigidly attached (e.g., by welding) to an adjacent pair of buck stays <NUM> so as to structurally support the upright and cross-support beams <NUM>, <NUM>. Each of the foundation beams <NUM> is most preferably connected between the adjacent pair of buck stays <NUM> at or just above the platform <NUM>-<NUM>.

The cross-support beams <NUM>, <NUM> dependently support a pair of runway beams <NUM> between which is connected a travelling bridge beam <NUM>. The bridge beam <NUM> includes an overhead travelling hoist <NUM>. As is shown in <FIG>, the runway beams <NUM> are supported in a cantilever manner by the end-most upright and cross-support beams <NUM>, <NUM> to that the terminal end portions extend beyond the wall <NUM> of the regenerator structure <NUM> thereby enabling access to the stacked supply of checker bricks <NUM> on the platform <NUM>-<NUM>.

Suitable operator controlled motors (not shown) are provided with the bridge beam <NUM> to allow it to reciprocally travel along the runway beams <NUM> in a longitudinal direction of the regenerator structure (i.e., in the direction of arrow A1 in <FIG>). Similarly, operator controlled motors (not shown) are provided with the hoist <NUM> to allow it to travel reciprocally along the bridge beam in a latitudinal direction of the regenerator structure <NUM> (i.e., in a direction of arrow A2 in <FIG>). The hoist <NUM> is connected to a suitable lifting sling <NUM> to allow the stacked supply of checker bricks <NUM> to be lifted up and into the interior of the regenerator structure <NUM>, e.g., by suitably operating the bridge beam <NUM> and hoist <NUM> so as to travel in the directions of arrows A1 and A2 while simultaneously causing the hoist <NUM> to raise or lower the checker bricks <NUM> (i.e., in a direction transverse to arrows A1 and A2). In such a manner, therefore, the checker bricks within the regenerator structure <NUM> may be replaced. It will be appreciated that the operation as described above will also allow the refractory blocks <NUM> to be installed as may be needed.

<FIG> show a sequence by which the overhead crane apparatus <NUM> may be assembled relative to an existing regenerator structure <NUM>. As was previously noted, the buck stays <NUM> are compressively held against the refractory blocks <NUM> forming the walls <NUM>, <NUM> of the regenerator structure by means of tie rods <NUM>. <FIG> and <FIG> therefore show an existing regenerator structure <NUM> with the tie rods <NUM> in place. As is shown in <FIG>, the tie rods <NUM> have been removed and a foundation beam <NUM>, upright support beam <NUM> and cross-support beam <NUM> installed as described previously. The particular sequence of removing the tie rods <NUM> and installation of the foundation beam <NUM>, upright support beam <NUM> and cross-support beam <NUM> is not critical provided that there is no structural interference therebetween. Thus, the tie rods <NUM> can be removed before or after installation of the foundation beam <NUM>, upright support beam <NUM> and cross-support beam <NUM> although it is typically preferred that the tie rods <NUM> be removed first as this ensures that they will not structurally interfere with any of the later installed beams.

<FIG> shows the runway beams <NUM> having been installed by connection to the cross-support beams <NUM>. Although not shown in <FIG>, the bridge beam <NUM> with the hoist <NUM> operatively connected thereto may likewise be installed onto the runway beams <NUM>. Thereafter, the installation of the refractory blocks <NUM> and/or checker bricks <NUM> may proceed in the manner as previously described.

A cross-fired glass furnace system <NUM> is depicted in <FIG> as being comprised of a central glass furnace structure <NUM> (e.g., a float furnace) and opposed pairs of regenerator structures <NUM>, <NUM>' operatively interacting with the furnace structure <NUM>. Each of the regenerator structures <NUM>, <NUM>' are as described previously with reference to <FIG> but are substantial mirror images of one another. Thus, corresponding structure described above with reference to regenerator <NUM> is shown by the same reference numeral in regenerator <NUM>', but with a prime (`) identifier. Thus, separate explanations of such corresponding structures for the regenerators <NUM>, <NUM>' will not be repeated.

The glass furnace structure <NUM>, like the regenerators <NUM>, <NUM>', includes vertically oriented buck stays <NUM>. The overhead crane apparatus employed for the glass furnace structure <NUM> is depicted as including laterally spaced-apart upright pairs of upright support beams <NUM> and a cross-support beam <NUM> spanning the distance therebetween. A foundation beam <NUM> extends between and is rigidly attached (e.g., by welding) to an adjacent pair of buck stays <NUM> so as to structurally support the upright and cross-support beams <NUM>, <NUM>.

The cross-support beams <NUM>, <NUM> dependently support a pair of runway beams <NUM> between which is connected a travelling bridge beam <NUM>. The bridge beam <NUM> includes an overhead travelling hoist <NUM>. The runway beams <NUM> are preferably supported in a cantilever manner by the end-most upright and cross-support beams <NUM>, <NUM> so that the terminal end portions extend beyond the end wall of the furnace structure <NUM> thereby enabling access to structural components to be hoisted by the travelling hoist <NUM>.

Suitable operator controlled motors (not shown) are provided with the bridge beam <NUM> to allow it to reciprocally travel along the runway beams <NUM> in a longitudinal direction of the regenerator structure (i.e., in the direction of arrow A1 in <FIG>). Similarly, operator controlled motors (not shown) are provided with the hoist <NUM> to allow it to travel reciprocally along the bridge beam in a latitudinal direction of the furnace structure <NUM> (i.e., in a direction of arrow A2 in <FIG>).

<FIG> depict alternative embodiments for supporting the cross-supports beams <NUM>, <NUM>' of the regenerator structures <NUM>, <NUM>', respectively, and/or the cross-support beams <NUM> of the glass furnace structure <NUM>. In this regard, <FIG> are depicted in relationship to supporting the cross-support beams <NUM> the regenerator structure <NUM>, but the disclosed embodiments are equally applicable to the regenerator structure <NUM>' and the glass furnace structure <NUM>.

As shown in <FIG>, the cross-support beam <NUM> may be attached to an arched support member <NUM> which extends between and is rigidly connected to (e.g., via welding) an adjacent pair of buck stays <NUM>. The cross-support beam <NUM> may be connected directly to an apex region of the arched support member <NUM>. Alternatively, as depicted in <FIG>, a pedestal support <NUM> may be provided extending upwardly from the apex region of the arched support member <NUM> to which an end of the cross-support beam <NUM> is attached.

In a similar manner, <FIG> shows another embodiment whereby a pair of upwardly convergent support members <NUM>, <NUM> extend between and are rigidly connected to an adjacent pair of buck stays <NUM>. The terminal ends of the convergent support members <NUM>, <NUM> may be connected directly to one another and to an end of the cross-support beam <NUM> (e.g., by welding). Alternatively, as depicted the terminal ends of the convergent support members <NUM>, <NUM> may be rigidly connected to an upwardly extending pedestal support <NUM> which in turn is connected to the cross-support support beam <NUM>.

Another embodiment is depicted in <FIG> whereby a buck stay extension member <NUM>-<NUM> is rigidly fixed to (e.g., via welding) an upper terminal end of the buck stays. The cross-support beam <NUM> may therefore be rigidly fixed to opposing pairs of such extension members <NUM>-<NUM> so as to span the distance across the regenerator structure. The runway beams <NUM> may therefore be connected directly to the cross-support beams <NUM>. According to the embodiment depicted in <FIG>, therefore, the use of upright support beams <NUM> and foundation beams <NUM> is not necessarily required.

Accompanying <FIG> and <FIG> depict embodiments of the invention which employ a monorail system. In this regard, as shown in <FIG>, a monorail member <NUM> is attached to selected ones of the buck stays <NUM> by generally inverted U-shaped hangers <NUM>. As shown, the hangers <NUM> include an outboard vertical leg 202a and an inboard vertical leg 202b connected to one another by a horizontal leg 202c. The monorail <NUM> is connected rigidly to the inboard leg 202b and supports a travelling hoist <NUM> of the variety discussed previously. The relative lengths of the legs 202a and 202b can be predetermined so as to accommodate varying height requirements that may be needed from one regenerator structure to another.

<FIG> is similar to the embodiment depicted in <FIG> except that the monorail <NUM> is connected rigidly to an inboard face of the buck stays <NUM>.

Although the embodiments have been described in relation to a cross-fired glass furnace system, the principles of the invention may likewise be embodied in any glass furnace design, such as float furnaces, end-fired furnaces, unit melters with recuperators and electric furnaces with shelf, sidewall or bottom electrodes.

Claim 1:
An apparatus for constructing a glass furnace regenerator structure (<NUM>) formed of large pre-cast refractory blocks (<NUM>) stacked on a foundation (<NUM>) to form end and side walls (<NUM>, <NUM>) and vertically oriented buck stays (<NUM>) externally supporting the walls (<NUM>, <NUM>) and an interior comprised of checker bricks (<NUM>), the apparatus comprising an overhead crane assembly (<NUM>) attached to and supported by the buck stays (<NUM>), wherein the apparatus further comprises:
opposed pairs of upright supports connected to at least a respective one of the vertically oriented buck stays (<NUM>), and cross-support beams (<NUM>) latitudinally spanning the glass furnace regenerator structure (<NUM>) and connected between respective pairs of the supports,
wherein the pairs of upright supports comprise:
a plurality of foundation beams (<NUM>) rigidly installed between respective adjacent pairs of buck stays (<NUM>);
pairs of upright support beams (<NUM>) each supported by a respective one of the foundation beams, and
wherein the overhead crane assembly (<NUM>) comprises:
a pair of raceway beams (<NUM>), each raceway beam (<NUM>) longitudinally extending relative to the regenerator structure and dependently supported by the cross-support beams (<NUM>); and
a hoist assembly moveably mounted to the raceway beam,
and
a bridge beam (<NUM>) moveably mounted to the pair of raceway beams for reciprocal movements therealong in a longitudinal direction of the regenerator structure; wherein
the hoist assembly (<NUM>) is moveably mounted to the bridge beam (<NUM>) for reciprocal movements therealong in a latitudinal direction of the regenerator structure, wherein one end portion of the raceway beam (<NUM>) is supported in a cantilever manner by a respective pair of support beams (<NUM>) and cross-support beam (<NUM>) and so as to extend beyond a respective end of the regenerator structure (<NUM>).