Boiler Blog | Nationwide Boiler Inc.

Even with the best pretreatment programs, boiler feedwater often contains some degree of impurities, such as suspended and dissolved solids. The impurities can remain and accumulate inside the boiler as the boiler operation continue, leading to carryover of boiler water into the steam, causing damage to piping, steam traps and even process equipment. The increasing concentration of suspended solids can form sludge, which impairs boiler efficiency and heat transfer capability.

One way to improve efficiency is to review your blowdown practices. This includes the use of an automatic blowdown control system by regulating water volume discharged in relation to the amount of dissolved solids present.  This system maintains proper water chemistry within acceptable limits, while minimizing blowdown and reducing energy losses. Cost savings come from the significant reduction in the consumption, disposal, treatment, and heating of water.

The U.S. Department of Energy's Industrial Technologies Program calculated annual cost savings associated with the installation of an automatic blowdown control system that reduced blowdown rate from 8% to 6%. The example below assumes a continuously operating natural gas-fired, 150 psig, and 100,000 lb/hr steam boiler. Makeup water temperature of 60 degrees, with boiler efficiency of 83%, with fuel valued at $3.00 MMBTU was used, and the total water, sewage and treatment costs are $0.004 per gallon.

The annual cost savings in the example above equals:

Boiler Feedwater:

Initial = 100,000 / (1-0.08) = 108,695 lbs/hr

Final = 100,000 / (1-0.060 = 106,383 lbs/hr

Makeup Water Savings = Initial - Final, or 108,695 lbs/hr - 106,383 lbs/hr = 2,312 lbs/hr

Enthalpy of boiler water = 338.5 Btu/lb; for makeup water at 60 degrees = 28 Btu/lb

Thermal Energy Savings = 338.5 - 28= 310.0 Btu/lb

Annual Fuel Savings = 2,312 lbs/hr x 8760 hrs/yr x 310.5 Btu/lb x $3.00/MMBtu / 0.82 x 106 = $23,007

Annual Water and Chemical Savings = 2,312 lbs/hr x 8760 hrs/yr x $0.004/gal / 8.34 lbs/gal = $9,714

Annual Cost Savings = $23,007 + $9,714 = $32,721
If you need additional information about feedwater systems or other ways you can decrease costs, contact Nationwide Boiler today and we are happy to discuss ways to improve your bottom line: 1-800-227-1966.

Do you want to obtain no-cost, technical services and incentives for your boiler systems, while decreasing your energy costs? Enovity, a sustainability consulting firm, provides cash incentives for boiler efficiency improvements to commercial, industrial and agricultural customers in PG&E's service territory who pay the Public Good Charge or Public Purpose Surcharge and operate hot water or steam boilers.

Through Envoity's Commercial Industrial Boiler Efficiency Program, facilities were able to save over $2.8 million in annual energy costs and receive $2.9 million in cash incentives during the 2006-2008 Program cycle. As a result of Enovity's success, the Program will continue through the next funding period.

Enovity helps its customers identify boiler system energy efficiency opportunities at their facility, perform measurements and analysis to estimate energy savings, assist in the implementation of the energy efficiency upgrades (such as reviewing contractor proposals), verify the installation of measures and the final savings achieved, and provides a financial incentive to help buy down the cost of these projects. Enovotiy has also been instrumental in combining boiler energy efficiency with NOx upgrades in order to improved boiler capacity, improve operations and maintenance and reduce greenhouse gas emissions.

Examples of these measures include burner control upgrades (for 30 ppm NOx), burner combustion fan VFDs, and SCR installation and ULN burner replacement (such as replacing a high excess air, ULN burner with a low excess air 30 ppm NOx burner with a CataStak SCR system).

Benefits of participating in the Program include reduced energy consumption, reduced greenhouse gas emissions, reduced maintenance costs and improved system efficiency What do you have to lose?

Also, read Nationwide Boiler's case study about how a major California food processor was able to receive cash incentives as well as energy and emissions reductions though the installation of a an E2Stak solution (CataStak SCR system and EconoStak economizer) and a condensing stack heat recovery system.

In order for your boiler to operate at peak efficiency, it is important that the correct balance of fuel and combustion air is achieved. Air and fuel ratios are controlled through linkages, fans, dampers and the increase or decrease of gas pressure. Gas pressure is controlled through a pressure regulator and a fan controls the volume of combustion air.
If there are any problems with the fan, more energy may be introduced into the system, causing decreased efficiency. To help ensure that your equipment is running at its peak performance, please review the common fan problems below.

Fan Capacity/Pressure is Below Rating:

1. Dampers or variable inlet vanes are not adjusted properly


2. Fan inlet or outlet conditions are impaired


3. Multiple air leaks within the system


4. Damage sustained to the blower wheel


5. Direction of rotation is incorrect

Fan Vibration:

1. Worn bearings


2. Unstable foundation


3. Foreign material in the fan causing an imbalance


4. Misalignment of bearings, couplings, wheel or v-belt drive


5. Damaged wheel or motor


6. Bent shaft


7. Worn coupling


8. Loose dampers or variable inlet vanes


9. Speed too high or incorrect fan rotation


10. Vibration to fan transmitted from another source


11. Uneven blade wear


12. Loose or broken bolts or set screws

Overheated Bearings:

1. Improper lubrication


2. Poor alignment


3. Damaged wheel or driver


4. Bent shaft


5. Abnormal end thrust


6. Dirt in bearings


7. Improper belt tension

Overload on Driver:

1. Speed too high


2. Direction of rotation is incorrect


3. Bent shaft


4. Poor alignment


5. Improper lubrication


6. Wheel wedging or binding on fan housing

Later this week Nationwide Boiler and other industry leaders will be attending our 29th Annual Charity Golf Tournament at Pebble Beach. This event is supporting the work of Via Services, a Silicon Valley based charity, dedicated to enrich the lives of children and adults with disabilities.

Thank you to all of our corporate sponsors and donors. We appreciate your generosity and support! More details to follow after the event. See you there!

Advanced Boiler Control Services, Applied Heat Recovery LLC, C&C Boiler, California Boiler Works, California League of Food Processors, C-B Nebraska Boiler, C-B Natcom, Central Boiler & Industrial Service, Coen Company, Inc., Cole Industrial, Inc., CRI Environmental Catalyst & Systems, CTi Controltech, In-N-Out Burger, E-tech, Inc., Faber Burner Company, Haldor Topsoe, Hayward Pipe & Supply, John Zink Company, McNulty Mechanical, Inc., Petrochem Insulation, Powerhouse Boiler, Process Heating (Anne Armel), R.F. MacDonald Co., S.T. Johnson Burners, Trailer Transit, Inc., Triple R Heavy Haul, Inc., Valin Corporation, VitalTherm, Wabash Power Equipment Co.