Claims:We claim:
1. A high volume slag pot (100) to favour slag management in a metal processing industry comprising:
a base (102);
a body (104) supported by the base (102), the body (104) being configured to receive slag and having diameter of an opening larger than the bottom diameter;
at least one tilting lug (106) provided on the body (104) either to tip the filled pot by a crane or to turn the empty pot in a position for cooling down or for repair;
a mechanism (108) provided on the body (104) to handle the pot by a slag pot carrier; and
a pair of mounting brackets (110) provided on the upper body at diametrically opposite points;
wherein the base (102), the body (104), the tilting lug (106), and the mounting brackets (110) are integrally constructed and provided has a single casted part.
2. The high volume slag pot (100) as claimed in claim 1, is made of cast-steel.
3. The high volume slag pot (100) as claimed in claim 2, wherein the composition of the cast-steel in weight % comprising of carbon in a content of 0.17%, manganese in a content of 1.45%, silicon in a content of 0.40%, phosphorous in a content of 0.015%, Sulphur in content of 0.002%, remaining weight % containing Fe and unavoidable impurities.
4. The high volume slag pot (100) as claimed in claim 1, is in round shape.
5. The high volume slag pot (100) as claimed in any one of the previous claim, wherein said high volume refers to a range of 8-15 cubic meter, more particularly 11cubic meter.
6. The high volume slag pot (100) as claimed in claim 1, wherein the interior body (104) has a liner of one or a plurality of slabs of refractory material.
7. The high volume slag pot (100) as claimed in claim 1, wherein the body has plurality of ribs on the outer surface.
8. A method of manufacturing a high volume slag pot (100), the method comprising the steps of:
mould making with an inner core and an outer core, wherein the mould comprises cavity reflecting a base (102), a body (104), a tilting lug (106), and a mounting brackets (110) constructed to provide a single casted part;
melting steel in a furnace,
pouring molten steel into a mould cavity; and
solidifying the molten steel to form a solidified single casted slag pot.
9. The method as claimed in claim 8, further comprises the step of heating the casted slag pot above austenitising temperature at about 915°C and allowing controlled cooling in furnace, intermediate holding at 600°C - 630°C and completion of cooling in furnace down to 300°C.
10. The method as claimed in claim 8 or claim 9, further comprises the step of polishing and dressing to provide fine inner surface to the body (104).
Dated this 31st day of March, 2022
For STEEL AUTHORITY OF INDIA LIMITED
By their Agent

(ANSHUL SUNILKUMAR SAURASTRI) (IN/PA 3086)
KRISHNA & SAURASTRI ASSOCIATES LLP
, Description:FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
&
THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
[SEE SECTION 10, RULE 13]

HIGH VOLUME SLAG POT;

STEEL AUTHORITY OF INDIA LIMITED, A GOVERNMENT OF INDIA ENTERPRISE, HAVING ITS ADDRESS AT RESEARCH & DEVELOPMENT CENTRE FOR IRON & STEEL, DORANDA, RANCHI-834002, STATE OF JHARKHAND, INDIA

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

TECHNICAL FIELD
[0001] This invention relates to pot used for carrying slag, wherein the pot is shifted through transfer car, more particularly this invention relates to a slag pot which is filled or partially filled with slag or a mixture of slag and metal from open hearth, electric furnaces, basic oxygen furnaces, blast furnaces or any slag producing furnace in an iron or steel plant.
BACKGROUND OF THE INVENTION
[0002] In a steel making process there are various byproducts which were formed during the various reactions that are being carried out in the steel making operation. During this process slag is produced which is one of the major byproduct which is formed due to the impurities present in the hot metal that is obtained from the iron making. In any steel industry high volume slag pot (volume in cubic meter) is used to collect the slag material before casting at caster. The slag pot is an apparatus which transfer collected slag to dumping yard. Three to four sequences of slag are being collected in slag pot before its dumping. Slag being sticky in nature and with decrease in temperature during the collection of slag the slag gets stick to slag pot. The removal of it is not an easy task. Hitting with dead weight at the bottom is required for cracking of the solidified slag from slag pot, therein high chances of slag pot being damaged due to high impact forces. A typical slag pot assembly comprises of a slag pot, trunnion ring and fasteners in its assembly. Trunnion ring is commonly used to support slag pot on slag cars which is a large circular casting in which the slag pot is fixed. Trunnions projecting from diametrically opposite ends are used to lift the slag pot. The trunnion ring is generally placed circumferentially on the slag pot machined collar circular surface area and arrested using fasteners at the position. The slag pot and trunnion ring are separately casted and assembled to accommodate in car.
[0003] In known structure of the slag pot assembly, slag pot over a period of time is gets damage due to frequent failure of fasteners [bolts], and thus bending of trunnion ring resulting in non uniform weight transfer to crane while lifting as well as to car while travel. The support contact between the trunnion ring and the pot brackets is also affected by bulging of the lower portion of the pot wall. These results in a sloppy fit between the pot and trunnion ring and necessitates custom fitting operations in the field. In this condition, the time and maintenance cost for slag pot repair and replacement is high.
[0004] In the known art, to arrest the failure of fastener and enhance the total cycle time of slag pot efforts are made with providing additional welded brackets at the junction of slag pot and trunnion ring. But it has also not given desired result.
[0005] Typically, in a steel plant the life of assembled slag pot is around 45 days and subsequently after every repair life achieved is additionally 15 to 20 days more. The total life out of slag pot and trunnion ring is around 8 to 10 months with several round of repair.
[0006] Therefore, there is felt a need of a slag pot that alleviates the drawbacks of conventional structures providing increased reliability with enhanced life cycle.
SUMMARY OF THE INVENTION
[0007] According to an aspect of the present invention, a high volume slag pot to favour slag management in a metal processing industry comprises a base, a body supported by the base, the body being configured to receive slag having diameter of an opening larger than the bottom diameter, at least one tilting lug provided on the body either to tip the filled pot by a crane or to turn the empty pot in a position for cooling down or for repair, a mechanism provided on the body to handle the pot by a slag pot carrier, and a pair of mounting brackets provided on the upper body at diametrically opposite points, wherein the base, the body, the mounting brackets and the tilting lug are integrally constructed and provided has a single casted part.

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
[0008] The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings in which:
[0009] Figure 1 represents front view of high volume slag pot, according to an embodiment of the present invention;
[0010] Figure 2 represents side view of the slag pot, according to an embodiment of the present invention; and
[0011] Figure 3 represents top view of the slag pot, according to an embodiment of the present invention.
[0012] Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.
DETAILED DESCRIPTION
[0013] In the following description, for the purpose of explanation, specific details are set forth in order to provide an understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known structures are shown in diagram form to facilitate describing the invention. One skilled in the art will recognize that embodiments of the present invention, some of which are described below, may be incorporated into several applications.
[0014] While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail, a preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspects of the invention to the embodiment illustrated. Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.
[0015] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein may be made without departing from the scope of the invention.
[0016] This invention relates to high volume slag pot which is filled or partially filled with slag or a mixture of slag and metal from open hearth, electric furnaces, basic oxygen furnaces, blast furnaces or any slag producing furnace in an iron or steel plant. In steel melting shop of iron and steel industry, furnace is used for converting/refining hot metal into liquid steel. Slag pots are being used in furnace shop for collection of liquid and semi solid slag.
[0017] The objective of the present invention is to eliminate trunnion ring and fasteners as the joining parts of slag pot and provide an improved/ rugged means for securing the pot lifting mechanism without any repetitive failure of sub assembly of slag pot i.e. trunnion ring so that it can be lifted and moved by a crane and transfer car, without loss of time, and without any susceptibility to risk.
[0018] Generally, slag pots are wearing products exposed to both mechanical and alternate thermal stresses the extent of them depends on the service conditions. An accurate design aims to minimize the impair of the operative environment on the service life: however, it remains always a compromise taking into consideration both physical and economical aspects, resulting in a variety of shapes tailored to the site operations. The shape of a slag pot depends primarily on the operational conditions it has to withstand. Thus, the following criteria’s are taken into consideration while producing a slag pot in the present invention: type of furnace that the slag pot will service, quantity and type of slag generated, method of handling and dumping the pot, heat impact during operation, dimensional restrictions, and pot maintenance procedures.
[0019] Considering above criteria, figures 1-3 shows various views of a high volume slag pot to favour slag management in a metal processing industry, according to an embodiment of the present invention. The slag pot comprises, a base (102), a body (104) supported by the base (102), the body (104) being configured to receive slag and having diameter of an opening larger than the bottom diameter, at least one tilting lug (106) provided on the body (104) either to tip the filled pot by a crane or to turn the empty pot in a position for cooling down or for repair, a mechanism (108) provided on the body (104) to handle the pot by a slag pot carrier, and a pair of mounting brackets (110) provided on the upper body at diametrically opposite points. The base (102), the body (104), the tilting lug (106), and the mounting brackets (110) of the slag pot (100) are integrally constructed and provided has a single casted part.
[0020] The slag pot (100) of the present invention is also provided with a plurality of ribs on its outside body (104) to provide additional stiffness. The bottom of body (104) is supported on the base (102) such that there is some ground clearance.
[0021] The slag pot is casted to have hollow interior to contain the slag and can be formed to any shape. In a particular embodiment the slag pot is in round shape.
[0022] The slag pots in steel industry are designed to operate for high volume. High volume in general refers to a range of 8-15 or more volume referred in cubic meter of slag collecting capacity. More particularly the volume can be 11cubic meter.
[0023] The interior of the slag pot may be lined with an expendable or disposable liner of one or a plurality of slabs of refractory material, usually of a heat-insulating type. After use, such a lining is simply removed and replaced. The centre of the floor of the slag pot, which is particularly liable to erosion when slag is first poured into the pot, may have a highly refractory brick set in it. Also, the interior of the pot, including any lining or insert in the base if used, may be sprayed prior to use with a refractory dressing.
[0024] According to an embodiment of the present invention, slag pot is made of cast-steel material, which is a fully killed steel, vacuum-degassed and processed to a fine grain size structure with improved properties both in toughness and in elongation. The composition of the cast-steel in weight % comprises of carbon in a content of 0.17%, manganese in a content of 1.45%, silicon in a content of 0.40%, phosphorous in a content of 0.015%, Sulphur in content of 0.002%, remaining weight % containing Fe and unavoidable impurities.
[0025] The slag pot made of cast iron of the present invention provides advantages such as, high resistance to impact load due to high ductility with excellent elongation values, considerable insensitiveness to excessive stresses caused by unequal heat load. Other advantages include, low cracking tendency because of high yield and tensile strength values, reduced occurring of heat induced deformation of slag pot(narrowing), increased life of the pot because of better material properties, that is can be three to four times better compared to pots of other conventional materials, and excellent weldability allowing the repair of cracks or other surface damages.
[0026] The material of slag pot is not limited to cast steel as described above, any high strength material having high strength, stiffness and good wear and corrosion property can be used to produce slag pot.
[0027] The casted slag pot according to the invention attains uniform thermal expansion over the body due to heat load during operation, and uniform contraction by a steered cooling after dumping.
[0028] According to an example embodiment, the mechanical properties for a slag pot made of cast steel is observed to be tensile strength >414 MPa, yield strength >207 MPa, elongation >24.0%, and reduction of area >35.0%. Additionally, at elevated temperature high temperature properties like creep resistance or creep strength are observed to be good.
[0029] The casted slag pot showed almost has no defects such as shrinkage cavity, shrinkage porosity, gas cavity, segregation, crack, non-metallic inclusions, thermal crack and cold crack etc. The slag pot also has good weldability, good repair ability, long life and low cost.
[0030] A method of manufacturing a high volume slag pot (100), the method comprising the steps of, in step 1: mould making with an inner core and an outer core, wherein the mould comprises cavity reflecting a base (102), a body (104), a tilting lug (106), and a mounting brackets (110) constructed to provide a single casted part, in step 2: melting steel in a furnace, in step 3: pouring molten steel into a mould cavity, and in step 4: solidifying the molten steel to form a solidified single casted slag pot.
[0031] The method of manufacturing a high volume slag pot (100), according to the present invention further comprises the step of heating the casted slag pot above austenitising temperature at about 915°C and allowing controlled cooling in furnace, further intermediate holding at 600°C - 630°C and completion of cooling in furnace down to 300°C.
[0032] The method of manufacturing a high volume slag pot (100), according to the present invention further comprises the step of polishing and dressing to provide fine inner surface to the body (104). The inner surface is processed by polishing and dressing so that the surface discontinuities which might cause some sticking of the slag are extensively removed. Additionally, the slag pot is descaled by pneumatic hammer and the outside is coated.
[0033] The slag pot according to the present invention integrally constructed and provided with reinforced mounting (in-cast) brackets at diametrically opposite points eliminates assembly/fastening of trunnion ring with pot and also to get span of 4 meter for resting in common car.
[0034] The slag pot according to the present invention has increased operating life as compared to the conventional slag pots. In a manner, the reliability and life of the slag pot is enhanced by at least 24 months by liquidating the issues discussed in the background art.
[0035] Additionally, the slag pot according to the present invention provides the following advantages as compared with the conventional slag pots known in the art. Reduced maintenance time, reduced manual efforts and time in manufacturing slag pot and trunnion ring separately, reduced machining hour at shops, reduced down time of handling crane, and reduced consumption of assembly studs.
[0036] Although there has been shown and described the preferred embodiment of the present invention, it will be readily apparent to those skilled in the art that modifications may be made thereto which do not exceed the scope of the appended claims. Therefore, the scope of the invention is only to be limited by the following claims.
[0037] List of Reference Numerals
Slag pot - 100
Base - 102
Body - 104
Tilting lug - 106
Mechanism - 108
Mounting brackets – 110