Evaluation of Various Heat Losses in a Rotary Furnace

---------------------------------------------------------------------***---------------------------------------------------------------------Abstract - Essar steel India Private limited is a fully integrated flat carbon steel manufacturer based in India from iron ore to ready to market products with a current capacity of 10 million tonnes per annum. Essar steels manufacturing facility comprises pellet making, iron making and steel making and downstream facilities spread across India. A rotary furnace is a rotated around its axis and rotation can also induce mixing or stirring of the sample. The rotary furnace will be rotating at 7.5 revolutions per minute. In that disc slurry will be placed and rotated those particles around it. Now water will be separated from the sample, and then filtrate the slurry in three different types of filtrations. Finally, the filter cake will come with a solid (90%) and moisture (10%). Heat the pellets by using induration process .Finally pellets are obtained. In the present work, sensible heat losses through pellet car, radiation losses, sensible heat loss through hot pellet discharge and cooling water losses and other losses are evaluated with respect to variation in quantity of pellet car, quantity of heat losses, quantity of pellet discharge, heating pellet car. Graphs are presented in order to study the effect of various losses with respect to input parameters like pellet discharge. The data obtained from analysis is consolidated in tables and presented in appendix.


1.INTRODUCTION
1.1. Furnace theory: A furnace is an equipment to melt metals for casting or heat materials for change of shape (rolling, forging etc.,) or change of properties (heat treatment). A furnace is essentially a thermal enclosure and is employed to process raw materials at high temperatures both in solid state and liquid state. Several industries like iron and steel making, non-ferrous metals production, glass making, manufacturing, ceramic processing, calcination in cement production etc. employ furnace.
The principle objectives are a) To utilize heat efficiently so that losses are minimum, b) To handle the different phases (solid, liquid or gaseous) moving at different velocities for different times and temperatures such that erosion and corrosion of the refractory are minimum.
1.2. Source of energy: a) Combustion of fossil fuels, that is solid, liquid and gaseous. b) Electric energy: Resistance heating, induction heating or arc heating. c) Chemical energy: Exothermic reactions 1.3. Types and Classification of Different Furnaces: Based on the method of generating heat, furnaces are broadly classified into two types namely combustion type (using fuels) and electric type. In case of combustion type furnace, depending upon the kind of combustion, it can be broadly classified as oil fired, coal fired and gas fired. 2. Convection due to the movement of hot gases over the stock surface at the high temperatures employed in reheating furnaces, the dominant mode of heat transfer is wall radiation. Heat transfer by gas radiation is dependent on the gas composition (mainly the carbon dioxide and water vapour concentrations), the temperature and the geometry of the furnace.
1.6. Performance Evaluation of a Typical Furnace: Thermal efficiency of process heating equipment, such as furnaces, ovens, heaters, and kilns is the ratio of heat delivered to a material and heat supplied to the heating equipment. The purpose of a heating process is to introduce a certain amount of thermal energy into a product, raising it to a certain temperature to prepare it for additional processing or change its properties. To carry this out, the product is heated in a furnace. This results in energy losses in different areas. For most heating equipment, a large amount of the heat supplied is wasted in the form of exhaust gases.

II. INTRODUCTION TO ESSAR STEELS
Essar Steel India Private Limited is a fully integrated flat carbon steel manufacturer based in India from iron ore to ready -tomarket products with a current capacity of 10 million tonnes per annum (MTPA). Essar Steel's manufacturing facility comprises ore beneficiation, pellet making, iron making and steel making and downstream facilities spread across India.  The above represented graph is variation of quantity of pellet car on sensible heat loss through pellet car. The quantity of pellet car is gradually decreasing with respect to sensible heat loss through pellet car.

Figure 6.2 variation of quantity of heat losses on radiation losses
The above represented graph is variation of quantity of heat losses on radiation losses. The quantity of heat loss with respect to radiation losses will increasing gradually. The above represented graph is variation of quantity of pellet discharge on sensible heat loss through hot pellet discharge. The quantity of pellet discharge with respect to sensible heat loss through hot pellet discharge will increasing gradually. The above represented graph is variation of Quantity of pellet car on cooling water losses. The quantity of pellet with respect to cooling water losses is increases gradually.

IV. CONCLUSION
The performance test on horizontal rotary furnace, by using this rotary furnace finally calculate a total heat consumption of pellets and percentage of pellets to produce a how much quantity per day. The variation of quantity of pellet car with respect to sensible heat loss through pellet car is gradually decreasing. The Variation of quantity of heat loss with respect to radiation losses is increasing gradually. The Variation of quantity of pellets discharge with respect to sensible heat loss through hot pellet discharge is gradually increases. The variation of quantity of pellet car with respect to cooling water losses is gradually increases.

V. FUTURE SCOPE
Based on the experimental study, obtained results and conclusions the following future scopes are summarized.
1. By using rotary furnace in future we implement the production of pellets also we improve the furnace.
2. We can also implement the computational fluid dynamics by using this rotary furnace.
3. In future comprises of manufacturing of pellets will increasing the production rate and as well as quality.