BURDEN MATERIAL DISCHARGE FROM THE ISOLATION BELL OF THE BLAST FURNACE CHARGING AREA

Blast furnace practice has been remaining the most suitable one in the steel production route. A rather large amount of blast furnaces (BF) is equipped with bell-like charging equipment. The discharge capability of such equipment has a drastic influence on the parameters of the charging operations and blast furnace driving rates. The charging features regulate in many cases burden materials descend and the parameters of the BF smelt. In relation to the mentioned, it is revealed that to determine the volume of the burden materials flow passing through the isolation bell of the BF charging area is an urgent scientific and engineering problem. A number of publications is devoted to the problem how to define the burden materials flow coming from the large bell. Most of these studies are grounded on the expressions by prof. Zenkov. However, there is a drawback apparently present in these findings and it can be expressed as the lack of the complex approach to incorporate such parameters as the material type, its granulometry and the geometry of the isolation bell outlet hole. The aim of the current research is to reveal the analytic dependence capable of determining the volumetric flow of the burden materials passing through the hole of the large bell. Thus, possessing the data on the burden materials flow and the geometry of the isolation bell outlet hole, one can determine the initial conditions for developing the trajectory of burden materials movement within the top area of the blast furnace. Moreover, the method proposed with the current publication permits determining the actual aggregate size of the burden materials coming to the BF top charge through the data of burden materials volumetric flow. Further, the actual size of the material particles being charged can be derived from the dependences presented in this work and this, in its turn, influences the permeability of the burden materials column for gases at a given point of BF top radius. Taking these data into account, the real opportunity emerges for an on-line correction of the BF drive by incorporating the certain on-line conditions of BF smelt. The results of the findings reported in this article are to be utilized for improvements on the automation system of blast furnace charge control.

Analysis of Large Bell Angle in Double Bell System on Burden Material Distribution and Layer Deformation in Mini Blast Furnace with Capacity 250 Ton/Day Using Solid Particle Model

The abundant of nickel ore resources in Indonesia and the regulations of Law of Coals and Minerals No. 4 year 2009 cause the development of nickel ore processing technology. One of the proven nickel ore processing technology is Mini Blast Furnace (MBF). When, the raw materials were fed to the MBF, there is a charging system to ensure good distribution of raw materials in MBF. The double bell charging system has an important role on the distribution of burden material in MBF. By optimizing the distribution and layers of the material burden, it will increase the stability and efficiency of the MBF process. Therefore, this study focused on analyzing the effect of large bell angle on the distribution of burden material in MBF using discrete element method. After analyzed, large bell angle differences produce different burden material distribution. For particle distribution, particles of small density (coal and dolomitee) tend to be concentrated in the center zone and particles of large density (ore) tend to be concentrated in the intermediate and peripheral zone. The larger angle of the large bell will increase particle falling velocity and the kinetic energy of the burden material. The most stable layer in MBF was obtained when using 65o bell angle. The MBF with 65o large bell angle is the best bell angle for MBF with capacity of 250 ton/day due to the greatest possibility of central working furnace operation.

Hypogene Point Karstification along Wadi Sirhan Graben (Jordan): A Sign of Oilfield Degassing?

Jordan is a country with a large area of limestone. Nevertheless, only a few limestone caves are known. Here we report about two caves along Wwadi Sirhan Graben of Jordan that appear to have formed by stoping upward of collapsed deep-seated hypogene cavities along breccia pipes. The first one, Uwaiyed Cave, is a small breakdown-dominated chamber in basalt of the Naslet Al-Dhirwa volcano; the second, Beer Al-Malabeh, is a large, bell-shaped sinkhole that has geologically recently opened up to the surface. Wwe discuss the possible processes that led to their formation. The review of the existing stratigraphy as obtained by oil well drilling suggests that no salt layers occur below the caves. Gypsum layers seem to be limited to 4 m in thickness, probably not enough to form the observed features. The remaining process is dissolution caused by ascending gas (H2S or CH4) -rich waters from the underlying oil and oil-shale fields. Wwhen such solutions reach the water table, bacterial oxidation may create enough dissolutional power to form localized and large cavities. Their collapse could lead to the observed collapse structures and would explain the paucity of other cave structures throughout southeastern Jordan.Keywords: Jordan, hypogene caves, sinkholes, oil fields, methane.

Epoiesen, egrapsen, and the organization of the vase trade

The obverse scene of the krater Oxford 526 by the Komaris Painter (Plate VI c) was the subject of J.D. Beazley's first contribution to this journal, an exemplary account from which the relevant passage deserves to be quoted:The space on A is divided by a pillar. To the left of the pillar is the painter's room. A young man dressed in an exomis and seated on a stool is painting the background of a large bell-krater of the same shape as our vase. His left arm is inside the krater, the rim resting on his thigh, and he is applying a large brush to the lower part. At his side is a stand, supporting the skyphos-shaped vase which contains the black paint. In front of the painter a fellow-workman moves to the right carrying a second krater by both handles. He has lifted it from the ground beside the painter and is carrying it out to put it down beside a third krater which stands on the ground at the extreme right of the picture. Presently the batch will go to the furnace. Beyond the pillar is another workman who moves to the right in the same attitude as the last. In his raised right hand he holds a skyphos by the foot. Perhaps he is taking it to join a batch of vases of the same shape, but more probably he has been sent by the busy painter to fetch more paint … A pleasant rhythm is thus imparted to the scene; the first figure is occupied with both vase and paint; the second with vase; and the third with paint.

A Bronze Age Glass Bead from Wilsford, Wiltshire: Barrow G.42 in the Lake group.

This paper deals with a unique glass bead from the second millennium BC in Wessex. Overlooked for more than 150 years, it has now been recognized for its intrinsic interest and general importance and is here presented for its wide significance in ancient Europe and beyond (pls 8 and 9).InAncient Wiltshire(1812, 210) Richard Colt Hoare recorded the excavation of a barrow in a group of Bronze Age date at Wilsford: ‘No. 7 is a large bell-shaped barrow’ (now regarded as a bowl barrow) ‘composed entirely of vegetable earth. It contained within a cist a little pile of burned bones with which had been deposited a very fine brass pin, a large stone bead which had been stained red, a bead of ivory and a lance head of brass’. This account is based on the records of William Cunnington (1807, 5–6), which include a transcription of a letter from the original excavator, a Mr Owen. The dimensions of the barrow are there given as 80 ft in diameter, 9 ft high, with a circular cist 18 in deep. The barrow is described as ‘No. 6 of Mr Duke's barrows’; there is thus a discrepancy in the numbering of the barrow, since Colt Hoare referred to it as Lake No. 7, while Cunnington kept to No. 6. The barrow, though recently ploughed, still stands to a height of over 2 m, and is today known as G.42 (Grinsell 1957, 211).