GENERAL

• Undertake regular Energy Audits.
  
• Plug all oil leakage. Leakage of one drop of oil per second amounts to a loss of over 2000 litres/year.
  
• Filter oil in stages. Impurities in oil affect combustion.
  
• Pre-heat the Oil. For proper combustion, oil should be at right viscosity at the burner tip. Provide heat capacity.
  
• Incomplete combustion leads to wastage of fuel. Observe the colour of smoke emitted from chimney. Black smoke indicates improper combustion and fuel wastage. White smoke indicates excess air & hence loss of heat. Hazy brown smoke indicates proper combustion.
  
• Use of low air pressure "film burners" helps save oil upto 15% in furnaces.
  

• Control excess air in furnaces. A 10% drop in excess air amounts to 1% saving of fuel in furnaces. For an annual consumption of 3000 kilo litres of furnace oil, means a saving of Rs. 3 lakhs.
  
• Reduce heat losses through furnace openings. Observation shows that a furnace operating at a temperature of 1000 °C having an open door Results in a fuel loss of 10 lit/hr. For a 4000 hrs. Furnace operation this translates into a loss of approx. Rs. 4 lakhs per year.
  
• Improve insulation if the surface temperature exceeds 20°C above ambient. Studies have revealed that heat loss from a furnace wall 115 mm thick at 650°C amounting to 2650 Kcal/m² /hr can be cut down to 850 kcal/m²/hr by using 65 mm thick insulation on the 115 mm wall.
  
• Proper design of lids of melting furnaces and training of operators to close lids helps reduce losses by 10-20% in foundries.
  
• Improve insulation if the surface temperature exceeds 20°C above ambient. Studies have revealed that heat loss from a furnace wall 115 mm thick at 650°C amounting to 2650 Kcal/m²/hr can be cut down to 850 kcal/m²/hr by using 65 mm thick insulation on the 115 mm wall.
  
• Proper design of lids of melting furnaces and training of operators to close lids helps reduce losses by 10-20% in foundries.
  

• Remove soot deposits when flue gas temperature rises 40°C above the normal. A coating of 3 mm thick soot on the heat transfer surface can cause an increase in fuel consumption of as much as 2.5%.
  
• Recover heat from steam condensate. For every 6°C rise in boiler feed water temperature through condensate return, there is 1% saving in fuel.
  
• Improve boiler efficiency. Boilers should be monitored for flue gas losses, radiation losses, incomplete combustion, blow down losses, excess air etc. Proper control can decrease the consumption upto 20%.
  
• Use only treated water in boilers. A scale formation of 1-mm thickness on the waterside would increase fuel consumption by 5-8%.
  
• Stop steam leakage. Steam leakage from a 3mm-diameter hole on a pipeline carrying steam at 7 kg/cm² would waste 32 kilo litresl of fuel oil per year amounting to a loss of Rs. 3 lakhs.
  

• A poorly maintained injection pump increases fuel consumption by 4gm/kwh.
  
• A faulty nozzle increases fuel consumption by 2gm/kwh.
  
• Blocked filters increase fuel consumption by 2gm/kwh.
  
• A continuously running DG set can generate 0.5Ton/Hr of steam at 10 to 12 bar from the residual heat of the engine exhaust per MW of the generator capacity.
  
• Measure fuel consumption per kWh of electricity generated regularly. Take corrective action in case this shows a rising trend.
  

• Compressed air is very energy intensive. Only 5% of electrical energy is converted to useful energy. Use of compressed air for cleaning is rarely justified.
  
• Increase in inlet air temperature by 3°C-increase power consumption by 1%. Ensure low temperature of inlet air.
  
• Reduction in discharge pressure by 10% saves energy consumption upto 5%. It should be examined whether air at lower pressure can be used in the process.
  
• A leakage from a ½" diameter hole from a compressed air line working at a pressure of 7 kg/cm
  
• Air output of compressors per unit of electricity input must be measured at regular intervals. Efficiency of compressors tends to deteriorate with time.
  

• Use of double doors, automatic door closures, air curtains, double glazed windows, polyester sun films etc. reduces heat ingress and air-conditioning load of buildings.
  
• Maintain condensers for proper heat exchange. A 5°C decrease in evaporator temperature increases specific power consumption by 15%.
  
• Utilization of air conditioned/ refrigerated space should be examined and efforts made to reduce cooling load as far as possible.
  
• Utilize waste heat of excess steam or flue gases to change over from gas compression systems to absorption chilling systems and save energy costs in the range of 50-70%.
  
• Specific power consumption of compressors should be measured at regular intervals. The most efficient compressors to be used for continuous duty and others on standby.
  

• Improper selection of pumps can lead to large wastage of energy. A pump with 85% efficiency at rated flow may have only 65% efficiency at half the flow.
  
• Use of throttling valves instead of variable speed drives to change flow of fluids is a wasteful practice. Throttling can cause wastage of power to the tune of 50 to 60%.
  
• Drive transmission between pumps & motors is very important. Loose belts can cause energy loss upto 15-20%.
  
• Modern synthetic flat belts in place of conventional V belts can save 5% to 10% of energy.
  

by Reed Miller, Industrial Heating
June 7, 2007

A newly released international report indicates that 2006 revenues for the Industrial Process Furnace and Oven Manufacturing Industry in the U.S. were approximately $1.96 billion. The gross profit was 25.5% - just under $500 million. It was a very good year to be in this business.

With this many furnaces being manufactured, it’s no wonder people are concerned about efficiencies with the prices of oil and natural gas at historically high levels. For many of the same reasons mentioned in our October 2006 editorial, long-term fundamentals continue to suggest that natural gas prices will remain relatively high and gradually increase. It was a warmer than average winter overall with demand about 3% lower than an average heating season. It was the third coldest February on record, however, resulting in a 6% higher February demand. In most of the U.S., it was also the coldest April in the last 10 years.

Future uncertainty always creates anxiety in this market. Will the summer be warmer than normal, and/or will it be an active hurricane season? Either will result in higher natural gas prices.

With energy costs at historic highs, a new paradigm has emerged. Labor once was the highest component in manufacturing costs and energy was the lowest. This has turned completely around, and discerning purchasers of this equipment are aggressively seeking ways to keep the energy production-cost component as low as possible.

Another recently concluded study conducted by Clear Seas Research for Industrial Heating sheds some additional light on the subject. Fully 96% of the burner-survey respondents indicate that natural gas is used to heat some or all of their process furnaces. Most furnaces (59%) were used for heat treatment.

When it comes to investing in furnace systems, 48% of survey respondents listed “energy savings” as a key factor while 41% chose fuel savings. Related to fuel savings, 13% of respondents gave “emissions reductions” as a key reason to invest in the next two years.

Perhaps not surprisingly, 64% of respondents to the burner survey listed “efficiency” as the most important characteristic they look at when purchasing a new burner. It’s no wonder that industry groups such as the Gas Technology Institute (GTI) utilize their resources to research ways to increase combustion efficiency in a variety of applications. GTI employs a staff of over 250 – 15% of whom hold Ph.D.s – many of whom are dedicated to improving process efficiencies.

Besides the obvious monthly cost savings associated with improving the efficiency of their process burners, many gas companies are offering rebates and incentives to customers who improve or replace qualifying lower-efficiency equipment. One example of this is The Gas Company in Southern California. More than $10 million in energy-efficiency rebates and incentives is available to its business customers in 2007. This money is divided between several different programs – more than one of which could apply to industrial customers making energy-efficiency improvements. Check with your natural gas company to see if you can take advantage of any similar incentives.