Boiler Blog | Nationwide Boiler Inc.

The need to operate a boiler efficiently in today's environment and competitive landscape is at the top of many plant owners and operators list. Unfortunately operating a boiler efficiently while meeting local emission regulations do not always go hand in hand. However, advances in boiler system design and low NOx technology solutions have made this a much more achievable task.

The list below includes 10 tips which can instantly improve overall boiler performance and sustainability, helping to achieve more cost-effective maintenance and operations of your steam system.

This list, along with general guidelines for each, will be published in an upcoming issue of Process Heating magazine. Please email Nationwide if you are interested in obtaining a copy.

1.    Reduce Excess Air

2.    Install an Economizer

3.    Install a Condensing Economizer

4.    Upgrade to VFD Fan Controls

5.    Install a Selective Catalytic Reduction System (SCR) with a Standard Low Excess Air/No FGR Burner

6.    Perform Proper Water Treatment

7.    Reduce Boiler Pressure

8.    Consider Boiler Blowdown Heat Recovery

9.    Upgrade to a High Turndown Burner & Controls

10. Implement an Energy Efficiency Program

The price of fuel is constantly fluctuating and with it comes creative ways to be more economical. Finding methods to be more energy efficient is never a waste of time. In the boiler room, efficiency improvements can be found by many sources, however, a common option for energy savings includes the use of an economizer. What is an economizer? The economizer is a fabricated assembly of finned tubing that captures waste heat extracted from the boiler’s stack flue gases; the exhaust that leaves the boiler stack (or “flue”).

It’s all about the principle of Heat Transfer. While low temperature water, or feedwater, enters a boiler system, high temperature flue gas exits. An economizer captures heat from the flue gas that would typically go to waste, and utilizes it to preheat the feedwater. By doing this, an economizer is able to increase thermal efficiency by decreasing the energy required to heat the water to steam. This will typically result in a reduction of 1% in fuel cost per 10 degree rise in feedwater temperature. Overall, an economizer can be a major cost savings for boiler owners and will easily provide a quick return on investment.

The economizers’ simple technology and static parts provide longevity and low maintenance, and they are available in multiple designs and configurations. Conventional economizers are cylindrical or rectangular and come in a range of sizes for both firetube and watertube boilers. Rectangular designs are more commonly used for larger industrial watertube boilers, and can be configured for vertical or horizontal gas flows, finned or bare tube design, and other additional options if needed. A condensing economizer can improve waste heat recovery even further by cooling the flue gas below its dew point, reclaiming both sensible heat from the flue gas and latent heat by condensing the flue gas water vapor.

BOILER EFFICIENCY COMPARISON
	Combustion Efficiency at 4% Excess Oxygen	Stack Gas Temperature
Boiler	78% to 83%	350F to 355F
Boiler with Standard Economizer	84% to 86%	250F to 300F
Boiler with Condensing Economizer	92% to 95%	80F to 150F

When determining whether an economizer is ideal for your boiler equipment, the location of the economizer into stack is important. To ensure the most thermal recovery during the process, you need to make sure the economizer is installed as close to the furnace breach as possible. This will help avoid thermal loss and cooling.

At Nationwide Boiler, we offer our EconoStak economizer as an optional addition (or a standard addition in some cases) on our fleet of watertube rental boilers. The EconoStak consists of the economizer as well as all of the associated piping and structural supports required for very efficient and safe operation. In addition, we are a West Coast representative for E-Tech Heat Recovery Systems, a leading provider of economizers for new, replacement, and retrofit applications.

Contact Nationwide Boiler today to see if an economizer is the right option for you, and be sure to check out our previous Boiler Basics 101 blogs. We review various topics each month, so stay tuned for the next edition!