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Del Williams

Lean

Why Modern Electric Boilers Are a Safer Choice

Advanced electrode boilers reduce risk of explosion, fire, and noxious emissions associated with fossil-fuel burning units

Published: Tuesday, September 6, 2022 - 11:02

In industry, gas-fired boilers have been the standard for decades to produce steam and heat process water. However, not all boilers are created equal in terms of safety. By definition, combustion-fueled boilers can emit harmful vapors, leak gas, and even cause explosions and fires.

In a recent example, a natural gas boiler was cited as the cause of a massive explosion and fire at a food processing plant in eastern Oregon that injured six and caused severe damage to the facility’s main building. Given the risks, many processors are turning to a new generation of electric boilers to dramatically reduce these hazards.

“With gas-burning boilers, any gas leak can increase the risk of an explosion wherever there are fuel lines, fumes, flames, or storage tanks,” says Robert Presser, vice president of Acme Engineering Products. “So, gas units must be continually monitored or periodically inspected.” Presser notes that state and municipal safety guidelines vary depending on boiler type and the expected frequency of inspection.

Acme Engineering is a North American manufacturer of boilers for large industrial and commercial applications. The company is an ISO 9001:2015-certified manufacturer of environmental controls and systems with integrated mechanical, electrical, and electronic capabilities.

In gas-fired boilers, explosions can result in the instantaneous combustion of highly flammable gas, vapor, or dust that has accumulated in a boiler. The force of the explosion is often much greater than the boiler combustion chamber can withstand.

Minor explosions, known as flarebacks or blowbacks, can also suddenly blow flames many feet from firing doors and observation ports, seriously burning anyone in the path of a flame.

Natural gas-fired boiler emissions also pose potential hazards in the form of emissions. This can include nitrogen oxides, carbon monoxide, nitrous oxide, volatile organic compounds, sulfur dioxide, and particulate matter, as well as the greenhouse gases carbon dioxide and methane, which accelerate climate change.

In addition, fossil fuel-burning boilers can face potentially dangerous operational issues stemming from excessive heat accumulation, particularly if the water is too low in the system to properly absorb the heat. High heat conditions can compromise the boiler, electrodes, and other equipment essential to operation.

To dramatically improve operator and environmental safety, industry is turning toward modern electric boilers that eliminate many of these risks. Many facility engineers believe that electric boilers can’t match the output of traditional, fossil fuel-burning units. But considerable advances in electric boiler technology can now match the capacity of large gas or oil-fired boilers in a much smaller footprint. The most advanced electrode boilers not only match the capacity of large gas- or oil-fired boilers but are safer and more compact. This maximizes energy efficiency, improves reliability, and minimizes maintenance.


Electrode boilers are safer, more energy-efficient alternatives to gas-burning units, and also have significant benefits in reliability and maintenance.

Presser explains that electric boilers use the conductive and resistive properties of water to carry electric current and generate steam. An AC current flows from an electrode of one phase to ground using the water as a conductor. Since chemicals in the water provide conductivity, the current flow generates heat directly in the water itself. The more current (amps) that flows, the more heat (BTUs) is generated, and the more steam produced.

As an example, in Acme’s CEJS High Voltage Electrode Steam Boiler, almost 100 percent of the electrical energy is converted into heat with no stack or heat-transfer losses. The electrodes of the jet-type electrode steam boiler are vertically mounted around the inside of the pressure vessel. This enables the unit to produce maximum amounts of steam in a minimum amount of floor space, with boiler capacity from 6 MW to 52 MW. Operating at existing distribution voltages, 4.16 kV to 25 kV with up to 99.9-percent efficiency, the boiler can produce up to 170,000 lb of steam per hour. With pressure ratings from 105 psig to 500 psig, the boilers are designed to ASME’s BPVC Section 1, and are certified, registered pressure vessels at the location of the boiler.

“With the jet-type electrode boilers, there are no combustion hazards because there are no flames, fumes, fuel lines, or storage tanks, which minimizes the risk of explosions and fires,” says Presser. In case of an electrical short, the breaker that protects the high-voltage circuit trips in a matter of milliseconds, protecting the boiler and the electrical network. There is no chance of electrical mishap or fire from the boiler.

Because the design doesn’t rely on combustion, it doesn’t create emissions that would endanger the operator or environment. In addition, the design eliminates many environmental issues associated with fuel-burning boilers, such as fuel fumes, fly ash, and large, obtrusive exhaust stacks.

This approach resolves safety issues related to potentially excessive heat accumulation with the system as well. Low-water protection is ensured because the absence of water prevents current from flowing and the electrode boiler from producing steam. Unlike conventional electric boilers or fossil-fuel boilers, nothing in the electrode boiler is at a higher temperature than the water itself. This prevents the risk of dangerous heat buildup in the boiler, electrodes, and other important components, even if scaling should occur, and thermal shock is eliminated.

“Electric boilers, and specifically the electrode units, are inherently the safest boiler design today,” explains Presser. “These units don’t need an operator because if anything goes wrong, the breaker trips, preventing further escalation of the issue.” 


As safer, more energy-efficient electrode boilers become more widely available, companies can protect their people and processes while minimizing required maintenance.

The electric boilers also improve safety by reducing industrial noise, which is an OSHA-regulated issue. Under OSHA’s noise standards, employers must lower noise exposure through engineering controls, administrative controls, or hearing protection devices (HPDs) that lessen occupational noise to specified levels.

The electric units are exceptionally quiet compared to fuel-fired boilers. “Unlike gas-powered burners that throttle like turbine engines almost continually, electric boilers keep operational noise levels down,” says Presser. “Because the loudest boiler component is a circulating pump motor, you can have a conversation next to one without the need to elevate your voice.”

Electrode units also offer significant benefits in reliability and maintenance. The absence of excessive temperatures and burnout ensures longer operating life. The boilers have a minimal number of components and electrical controls. With no fuel residues, along with fewer parts and simpler control systems, cleaning and maintenance requirements are reduced and reliability is enhanced.

Processors have long sought to improve safety, yet options have been limited. Now, as safer, more energy-efficient alternatives become available in the form of electrode boilers, companies can protect their people and processes more completely while minimizing required maintenance.

 

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About The Author

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Del Williams

Del Williams is a technical writer based in Torrance, California. He writes about business, technology, health, and educational issues, and has a master’s degree in English from California State University-Dominguez Hills.