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TMI Blog1993 (3) TMI 217X X X X Extracts X X X X X X X X Extracts X X X X ..... ustrial Furnaces where glass is actually melted and the temperature is always higher than 1550OC. He has further held that the Refractory bricks imported are to be used in front wall of the Regenerator where normal temperature would be around 1400OC and hence the benefit under Notification No. 242/76-Cus. would not be available to the item in question. The learned Collector (Appeals) has held as follows : I have gone through the written and oral submissions and also the Glossary of Terms relating to Refractory materials as appearing in the Handbook No. IS-4041-1987 by the ISl and the following are the definitions which are relevant for examining the merits of the appeal LB 9.30 Port - Furnace opening through which liquid for gaseous fuel or air or both for combustion is introduced. 9.31 Recuperator - A continuous heat exchanger in which heat from combustion products is transferred to incoming air or gas through metal or refractory walls. 9.32 Regenerator - A periodic heat exchanger which alternatively, receives heat from combustion products and gives up heat to incoming air or gas. 9.44 The bottom of a door opening in a furnace. 23.1 Back wall, End wall or Cable wall - T ..... X X X X Extracts X X X X X X X X Extracts X X X X ..... e various walls also constitute parts of the furnace. Now in the definition of a regenerator (9.32) as shown above, the same has not been defined as a part of the tank furnace on the same lines as the other parts enumerated above. Now in the ISI Book, page 67, two cross section views of the tank furnace have been given i.e. (1) when it is viewed from above (Vertical top) and the other when it is viewed sideways (horizontal). In the vertical view the double lines show the equipment sections outside the furnace lines. The various zonal and parts of the tank furnace included therein are 23.15, 23.33, 23.49,23.8,9.44,23.17 and 23.7. The double line separates the regenerator from the tank furnace and this shows that the regenerator is not treated as a part of the furnace. The fuel mixture after combustion is drawn into the regenerator through ports so as to take out the heat energy and transfer it to the fresh mixture of fuel and air and to preheat it to a temperature of 175OC. A furnace is essentially an equipment in which the combustion of fuel takes place so as to generate heat for melting etc. as mentioned in the Explanatory notes. At the most, a furnace may have various sections, o ..... X X X X Extracts X X X X X X X X Extracts X X X X ..... having given the finding that the Regenerator is essential for the functioning of the Tank furnace and although such furnace is so designed that it cannot work without the Regenerator yet to hold that it is not a part of the furnace, was therefore, not justified. The imported items are used as component parts of the furnace is clearly evident from the manufacturers catalogue and, therefore, the denial of the benefit of the notification is not justified. 4. The learned advocate relied on the ruling of the Tribunal in the case of Steel Authority of India v. Collector of Customs as reported in 1989 (42) E.L.T. 89. In this case also, the question of classification of specially designed refractory brick came up for determination. The Bench had held that refractory bricks, not being component parts of industrial furnace, are not entitled to the benefit of the notification. It had been further held that teaming ladles used in the construction of the present refractory bricks of special quality and shape are receptacles for molten steel. It was held that the ladles were not incorporated into, nor are they integrated parts of furnace. The Bench has also concluded that for an article to ..... X X X X Extracts X X X X X X X X Extracts X X X X ..... s an integral part of the furnace. The trade catalogue also support the plea that Regenerator is a zone of furnace. 7. We have carefully considered the submissions made by both the sides and have perused the records. The question that arises for our consideration is as to whether the imported item which is used as replacement part in the Regenerator, would be a part of the furnace. In other words, is the Regenerator installed in the importers furnace an integral part of the furnace to enable them to claim the benefit of the notification in question? The lower authorities have denied the exemption on the ground that the Regenerator is an independent unit and cannot be considered, as an integral part of the furnace and, therefore, the imported refractory bricks which are going to be used in the refractors cannot be deemed to be used as part of furnace. The reasoning of the learned Collector has already been extracted above. Is this finding sustainable in the light of the finding given by the Tribunal in the case, of Steel authority of India (supra)? The question that came up for consideration in that case is the use of refractory bricks specially designed for use for construction ..... X X X X Extracts X X X X X X X X Extracts X X X X ..... lows that what has to be considered in the light of the above ruling is as to whether Regenerator, to which this imported items are being used as replacement parts, is an integral part of the furnace. Let us examine the evidence placed before us to answer this point. 8. The importers in their annexure to their letter dated 8-1-1990 to the Assistant Collector of Central Excise, Appraising Department, Group III, Bombay, have stated that - Ours will be a end fired regenerative glass melting industrial furnace which will be used for melting (pressed ware) glass. This furnace will be Natural gas fuel fired with regenerative heat recovery system. Furnace shall be with high fuel efficient regenerators which will save around 40% min. of fuel compared to conventional furnaces. They have given two diagrams of their furnace which shows the location of port and Regenerator. The working of the Furnace has been given as follows - Raw materials of the mixed glass batch is fed from the dog house located on R.H. side of the melting tank with the help of batch charger. Mixed batch contents are quartx sand, feldspar, lime powder. Dolomite, soda ash and Barytes and glass cultet. Batch mov ..... X X X X Extracts X X X X X X X X Extracts X X X X ..... maining refractory will be indigeneously selected based on different temperature gradient and thermal shock, cold crushing strength requirement." 9. At page 504 of McGraw Hill Encyclopedia of Science and Technology, appears a note on Heat Exchanger . A few paras of the said notes are extracted below - A device used to transfer heat from a fluid flowing on one side of a barrier to another fluid (or flowing on the other side of the barrier). When used to accomplish simultaneous transfer and mass transfer, heat exchangers become special equipment types, often knows the other names. When fired directly by a combustion process, they become furanaces, boilers, heaters, tube-still heaters and engines. If there is a change in phase in one of the flowing fluids - condensation of steam to water for example - the equipment may be called a chiller, evaporator, subliment distillation-column reboilers, still, condenser or cooler-condenser. Heat exchangers may be so designed that chemical reactions or energy generation processes can be carried out within them. The exchanger becomes an integral part of the reaction system and may be known, for example, as a nuclear-reactor catalytic reac ..... X X X X Extracts X X X X X X X X Extracts X X X X ..... e in the melter ranges from about 2850 to 2920OF. Usually, the safe limit is determined by the particular glass and the softening point of the silica crown (roof) which softens and drips starting at 2950OF. The reason for always using silica in the roof over the glass rather than some more resistant material is that silica, in addition to being a strong brick at high temperature is one in which the corrosion products are compatible with the glass whereas the other materials are more likely to produce insoluble stones and other inclusions. In the breast wall and below the glass most of the refractories in use now are heavier than the glass very dense, and resist attack by the molten glass much better than those of quite a few years ago. All refractories in the sides of the melter below the glass need to be force cooled on the side face as their life is short, especially at the glass surface line where, the rate of corrosion is greatest. As a furnace ... . more and more cooling wind is applied at other critical spots as they develop." At page 279 appears a write up on Regenerators . A few paragraphs are noted below A furnace without adequate regenerator capacity is at a d ..... X X X X Extracts X X X X X X X X Extracts X X X X ..... ss making process is carried out at rather high temperatures, which vary considerably depending on the type of glass being manufactured and the production demands on a particular unit. Temperatures generally range from about 1800O (982OC) to 3000OF (1649OC) from me very coldest portion of a furnace to the very hottest portion of a high production furnace. It can be stated categorically, that the severity of reactions, between glass or glass vapour or batch solids and refractories increases strongly with temperature. For normal corrosion reactions, it can be stated that this is a logarithmic function. The melting area of the furnace is generally the highest temperature area with a marked decrease in temperature in the feeder channels and other such arrangements leading to forming machines. In the superstructure, areas of the furnace, the same temperature relationships hold. In regenerative chambers, the temperature generally is highest at the top of the checker setting and decreasing going down the setting to the rider arches. However, in this area the temperature varies with reversals and is not nearly so uniform as in the tank superstructure proper and in the melter basis where te ..... X X X X Extracts X X X X X X X X Extracts X X X X ..... irs, often a lot of good refractory is thrown away because it is most economical to repair infrequently and to repair rather large areas simultaneously. Such shutdowns for regenerator repair are always expensive, but especially so if they are unscheduled. Obviously this is one of the areas of the glass furnace requiring some fundamental improvements in materials to balance out life so that every large areas of the furnaces can be repaired simultaneously and on a scheduled basis. The areas encompassed by this discussion are meant to include all elements of the heat regeneration system proper but excluding the port necks, port crowns, etc. which have been discussed earlier. Some areas of this system i.e. flues, stacks etc. form more or less permanent parts of the glass furnace structure; however, the regenerator chamber proper is subject to periodic replacement and the discussion will be concentrated on materials and practices for these areas. Walter and Kivala have made an excellent summary of the chief features of the environment affecting refractories for these areas, and the factors affecting the life of materials used. The regenerator chamber and the checker setting do not f ..... X X X X Extracts X X X X X X X X Extracts X X X X ..... context otherwise requires, composite machines consisting of two or more machines fitted together to form a whole and other machines adapted for the purpose of performing two or more complementary or alternative functions are to be classified as if consisting only of that component or as being that machine which performs the principal function. Where a machine (including a combination of machines consists of individual components (whether separate or interconnected by piping, by transmission devices, by electric cables or by other devices) intended to contribute together to a clearly defined function covered by one of the headings in Chapter 84 or Chapter 85, then the whole falls to be classified in the heading appropriate to that function." The Explanatory notes under Heading 84.14 of CCCN is also extracted supra from the ruling of SAIL s case. The regenerator has become an integral part of the furnace and applying this note, the regenerator would have to be classified alongwith furnace. The SAIL s case has clearly laid down the principle on this aspect. The ratio supports our finding. The regenerator having become an integral part of the furnace, die refractory bricks importe ..... X X X X Extracts X X X X X X X X Extracts X X X X
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