Abstract:


The need of energy conservation has assumed paramount importance due to the rapid growth of process industries causing substantial energy consumptions in textile operations. And this has made pathway to conservation of energy which can be affected through process and machinery modifications and implementation of technological advancements relating to process optimization as well as development of newer methods to meet the challenge of substantial energy saving in textile wet processing. Thus, there is a necessity for replacing the conventional methods by the latest processes which will lead to considerable savings in terms of energy, money and time.


Global energy crisis, as well as high cost of fuels resulted in more activities to conserve energy to maximum extent. The textile industry retains a record of the lowest efficiency in energy utilization and is one of the major energy consuming industry. About 34% of energy is consumed in spinning, 23% in weaving, 38% in chemical processing and another 5% for miscellaneous purposes. Power dominates consumption pattern in spinning/weaving, while thermal energy is major for chemical processing. It is known that thermal energy in textile mill is largely consumed in two operations, in heating of water and drying of water. Fuel consumption in textile mills is almost directly proportional to amount of water consumed. Hence, if consumption of water can be reduced, it will also save energy.


It is, therefore, an important aim of industrial fundamental research to develop new technologies to optimize conventional processes in order to conserve energy by basically adopting novel concepts discussed in the paper.


Introduction


Energy is one of the most important ingredients in any industrial activity. However, its availability is not infinite. Global Energy crisis, as well as high cost of fuels resulted in more activities to conserve energy to maximum extent. The textile industry retains a record of the lowest efficiency in energy utilization and is one of the major energy consuming industries. About 34% of energy is consumed in spinning, 23% in weaving, 38% in chemical processing and another 5% for miscellaneous purposes. Power dominates consumption pattern in spinning/weaving, while thermal energy is major for chemical processing.


It is known that thermal energy in textile mill is largely consumed in two operations, in heating of water and drying of water. Fuel consumption in textile mills is almost directly proportional to amount of water consumed. Hence if consumption of water can be reduced, it will also save energy. Conservation of energy can be affected through process and machine modification, proper chemical recipes, and new technologies.

The possibilities of utilizing new energy resources like solar energy, wind power, tidal power, nuclear energy, etc. are to be explored. But initial cost of production will increase in step with cost of oil, which makes development of such sources doubtful in terms of cost incurred.


Focus Areas for Energy Conservation


Thermal Energy:


As already indicated, wet processing of textiles consume a very high proportion of thermal energy mainly for the evaporation of moisture from textiles. at various stages of wet processing and also for heating of process chemicals. Table 1 indicated the department wise percent steam consumption in a composite textile mill.


Steam is generated employing boilers by using either coal or furnace oil and lately low sulphur heavy stock oil available from the refineries as fuel having average calorific values of 4200 6200, 10280 and 10700 Kcal respectively.


Thermal energy in the form of steam is supplied to the various equipment's through pipe for this purpose; steam generated in the boiler is bifurcated into the required branches through the main steam header. The major consumption of steam is for evaporating moisture from treated textiles as compared to that of heating of process chemicals. Following are the tables which gives the average steam consumption in some unit operations and also in each stage of wet processing.