Training Manual on Energy Efficiency - APO Asian Productivity ...

More documents

Recommendations

Info

<strong>Training</strong> <strong>Manual</strong> on Energy Efficiency for Small and Medium Enterprises Always use the most economical way to remove the bulk of water from the wet material. Steam can then be used to complete the process. For this reason, hydro extractors, spin dryers, squeeze or calendar rolls, presses, and other equipment are initially used in many drying processes to remove the mass of water. The efficiency with which this operation is carried out is most important. For example, in a laundry for finishing sheets, the normal moisture content of the sheets as they leave the hydro extractor is 48% by weight. Thus, the steam heated iron has to evaporate nearly 48% of water. This requires 62kg of steam. If, due to inefficient drying in the hydro-extractor, finishing sheets arrive at the iron with 52% moisture content, 52kg of water has to be evaporated; the steam quantity required is 67 kg. So, for the same quantity of finished product, the steam consumption increases by 8%. When steam reaches the place where its heating is required, it must be ensured that the steam has no more work to do than is absolutely necessary. Air–heater batteries, for example, which provide hot air for drying, will use the same amount of steam whether the plant is fully or partly loaded. So, if the plant is running only at 50% load, it is wasting twice as much steam (or twice as much fuel) as is necessary. By reducing work done by steam, energy saving can be achieved by the following measures: • Reduction in operating hours; • Reduction in steam quantity required per hour; • Use of more efficient technologies; • Avoiding part load operations; and • Minimizing wastage. Where feasible, the heating of a liquid by direct injection of steam is often desirable. The equipment required is relatively simple, cheap, and easy to maintain. No condensate recovery system is necessary. The heating is quick, and the sensible heat of the steam is used up along with the latent heat, making the process thermally efficient. If the dilution of the tank contents and agitation are not acceptable in the process (i.e., if direct steam agitation is not acceptable), indirect steam heating is the only answer. Ideally, the injected steam should be condensed completely as the bubbles rise through the liquid. This is possible if the inlet steam pressures are kept very low, around 0.5 kg/cm2 to 1.0 kg/cm2 3.9.9 Proper utilization of directly injected steam . If pressures are high, the velocity of the steam bubbles will also be high, and they will not have sufficient time condense before they reach the surface. A large number of small-diameter holes (2–5mm), facing downwards, may be drilled on the steam distributor pipe. This will help in dissipating the velocity of bubbles in the liquid. Adopting thermostatic control of steam admitted is highly desirable. - 30 -
3.9.10 Proper air venting Energy Efficiency in Steam Distribution and Utilization A 0.25mm thick air film offers the same resistance to heat transfer as a 330mm thick copper wall. The presence of air inside the process equipment will reduce the partial pressure of steam in the steam air mixture, thus dropping the overall temperature of the steam air mixture, which is the heating medium. However, it is impossible to avoid the entry of air into a steam system that is working intermittently. If the steam condenses during the shutdowns, air enters the process equipment from the steam mains at the time of startup. Adequate air venting provision should be made at appropriate positions in the pipelines, to purge air as quickly as possible from the equipment, making heat transfer more efficient. - 31 -
Page 2 and 3: The opinions expressed in this publ
Page 4 and 5: 2.5 Boiler water treatment 14 2.6 E
Page 6 and 7: 7. ENERGY EFFICIENCY IN PUMPS 64 7.
Page 8 and 9: LIST OF TABLES 1-1 Gross calorific
Page 10 and 11: 6-1 Induction motor 56 6-2 Boosting
Page 12 and 13: FOREWORD With the rising costs of e
Page 14 and 15: Training M
Page 44 and 45: 4. ENERGY EFFICIENCY IN FURNACES 4.
Page 68 and 69: 6. ENERGY EFFICIENCY IN ELECTRIC MO
Page 76 and 77: 7. ENERGY EFFICIENCY IN PUMPS 7.1 P
Page 88 and 89: 8. ENERGY EFFICIENCY IN FANS 8.1 IN
Page 92 and 93:
Training M
Page 94 and 95:
Training M
Page 96 and 97:
Training M
Page 98 and 99:
Training M
Page 100 and 101:
9. ENERGY EFFICIENCY IN COMPRESSED
Page 102 and 103:
Training M
Page 104 and 105:
Training M
Page 106 and 107:
Training M
Page 108 and 109:
Training M
Page 110 and 111:
10. ENERGY EFFICIENCY IN REFRIGERAT
Page 112 and 113:
Training M
Page 114 and 115:
Training M
Page 116 and 117:
Training M
Page 118 and 119:
Training M
Page 120 and 121:
Training M
Page 122 and 123:
Training M
Page 124 and 125:
Training M
Page 126 and 127:
Training M
Page 128 and 129:
Training M
Page 130 and 131:
Training M
Page 132 and 133:
12. CLEAN DEVELOPMENT MECHANISM 12.
Page 134 and 135:
Training M
Page 136 and 137:
Annex S. No. Enconomic Opportunity
Page 138 and 139:
Training M
show all

Training Manual on Energy Efficiency - APO Asian Productivity ...

Create successful ePaper yourself

Delete template?

Save as template?