Having investigated the leading international experience specialists of SME Tomsk Electronic Company could offer the most rational design for using of SICON conveyor system (ContiTech Scandinavia AB, Sweden) for the upgrade of Blast Oxygen Shop of Nizhny Tagil Metallurgy Works. It required a special approach to designing of the gallery in order to provide a startup of such system. The best solution was the gallery design supported by a welded tubular construction with 2.4 m in diameter and total length of 400 m, with spans up to 24 meters, also the gallery could be supported by the existing structures of the shop (Figures 1, 2, 3). All structural elements of Sicon conveyor system are mounted directly to internal walls of the tubular gallery.
Sicon conveyor system is a closed belt conveyor, transporting bulk materials through sophisticated routes going around the existing equipment and utility lines under angle of 180º and elevation up to 35º, and no transfer stations are required. The folded Sicon belt forming a closed bag (Figure 4) transports materials through the whole route of the conveyor avoiding any spills. The belt gets open only in the loading and discharge points, thus much less suction pipes are required and the length of bulky dedusting ducts is much shorter. Due to this advantage no suction pipes are required through the whole route of the conveyor but for loading and discharge stations.
Belt edges are made of the profile with vulcanized steel cord. Profiles are used for suspending the belt on support and guide rollers while it is moving. Steel cord takes the strain generated by the conveyor actuators when the belt is moving through rollers and drums. The working part of the belt, transporting the materials is made of highly elastic rubber fabric material.
In order to control the conveying system for stock materials supply for Blast Oxygen Shop #1, SME TEC developed an intelligent control system with a special software, which enables the standby track to perform the following functions:
Adjustment of supply of bulk materials at the loading station
Two level monitoring of the belt filling up with materials
Monitoring of belt tension
Monitoring of belt movement
Monitoring of belt misalignment at the turning and actuating stations
Monitoring of belt temperature
Automatic distribution and adjustment of torque between four actuating stations
The design of Sicon conveyor system of the stock materials supply for Oxygen Blast Shop #1 includes the tension station with an actuator, turning station (with no actuator), two turning stations with actuators and one tension station at the strait part of the conveyor. As per the developed control software the four actuators can support the long term operation on three actuators and a short term operation on two actuators and the load will be distributed between operating actuators in case of failure of one or two actuators. This enhances the general reliability of the conveyor system.
Thus Sicon conveyor system allowed locating the stock materials transportation system in the limited space of the existing production facilities, supplying of the materials through the inclined route 480 m long and with conveyor belt length at 960 m, with three turns for 90º with no transfer stations, and thus dust release has been significantly reduced.
А) General Layout of Conveyor Gallery
B) Diagram of Sicon Conveyor Route
The outcomes of guarantee testing before startup of the standby tract proved the capacity to be 310 tons per hour (140 cu.m per hour) for the heaviest material (iron nuggets) and more than 190 tons per hour (210 cu.m. per hour) for the lightest material (lime).