Advanced electrode boilers dramatically reduce the risk of explosion, fire, and noxious emissions associated with fossil fuel burning units In industry, gas-fired boilers have largely been the standard for many decades to produce steam as well as heat process water. However, not all boilers are created equal in terms of safety. By definition, combustion-fueled boilers Read more
Robert Presser
Advanced electrode boilers dramatically reduce the risk of explosion, fire, and noxious emissions associated with fossil fuel burning units
In industry, gas-fired boilers have largely been the standard for many decades to produce steam as well as 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. So, gas units must be continually monitored or periodically inspected,” says Robert Presser, Vice President of Acme Engineering Products, who 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 ignition and 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 (NOx), carbon monoxide (CO), nitrous oxide (N2O), volatile organic compounds (VOCs), sulfur dioxide (SO2), and particulate matter (PM), as well as the greenhouse gasses carbon dioxide (CO2) and methane (CH4), which accelerate global warming.
In addition, fossil fuel burning boilers can also 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. The most advanced electrode boilers not only match the capacity of large gas or oil-fired boilers but are safer and more compact, maximizing energy efficiency, improving reliability, and minimizing maintenance.
Although many facility engineers are familiar with gas-fired boilers, many believe that electric boilers cannot match the output of the traditional, fossil fuel burning units. Due to considerable advances in electric boiler technology, however, such technology can now match the capacity of large gas or oil-fired boilers in a much smaller footprint.
Presser explains that electric boilers utilize the conductive and resistive properties of water to carry electric current and generate steam. An A.C. 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% 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 6MW to 52MW. Operating at existing distribution voltages, 4.16 to 25 KV with up to 99.9% efficiency, the boiler can produce up to 170,000 pounds of steam per hour. With pressure ratings from 105 psig to 500 psig, the boilers are designed to ASME 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.
Since the design does not rely on combustion, it does not 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.
The approach resolves safety issues related to potentially excessive heat accumulation with the system as well. Low water protection is absolute since 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 build up 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. These units do not need an operator because if anything goes wrong, the breaker trips, preventing further escalation of the issue,” explains Presser.
The electric boilers also improve safety by reducing industrial noise, which is an OSHA regulated issue. Under OSHA’s Noise Standard, the employer must lower noise exposure through engineering controls, administrative controls, or Hearing Protection Devices (HPDs) to attenuate the occupational noise received by the employee’s ears to within levels specified.
In this regard, the electric units are also 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.”
While safety of the electrode units is superior, there are also significant benefits in terms of reliability and maintenance. The absence of excessive temperatures and burnout assures longer operating life. The boilers have a minimum number of components and electrical controls. With no fuel residues, along with fewer parts and simple 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 more widely available in the form of state-of-the-art electrode boilers, companies can protect their people and processes more completely while minimizing required maintenance.
For more info, contact Robert Presser at Acme Engineering at e-mail: rpresser@acmeprod.com, phone: 888 880-5323, or web: www.acmeprod.com/
Del Williams is a technical writer based in Torrance, California.
With zero emissions, economical electric steam and hot water boilers deliver maximum heat and hot water in minimum spatial footprint Due to the threat of global warming as well as international commitments to the Paris Accord on Climate Change, municipalities and regions using district heating in Europe and North America are tasked with significantly reducing Read more
With zero emissions, economical electric steam and hot water boilers deliver maximum heat and hot water in minimum spatial footprint
Due to the threat of global warming as well as international commitments to the Paris Accord on Climate Change, municipalities and regions using district heating in Europe and North America are tasked with significantly reducing their environmental footprint in record time. With district heating, towns or large areas typically receive heat and hot water, distributed to commercial, residential, or public buildings at greater economies of scale than individual heating systems.
In response, last year the 27-nation European Union (EU) agreed to cut greenhouse gas carbon emissions by 55% by 2030 compared to 1990 levels. According to a recent report that has tracked the EU’s power sector since 2015, renewables surpassed fossil fuels last year (38% to 37%), indicating that municipalities relying on district heating are already pivoting away from often inefficient, outdated equipment that produces excess carbon emissions.
Even the U.S., which recently rejoined the Paris Agreement, has targets for American businesses to achieve a carbon pollution-free power sector by 2035 and a net-zero economy by 2050.
While the interest of regions using district heating in electric boilers has waxed and waned in the last century, suddenly it is in vogue again. Whether to honor Environmental Social and Governance (ESG) goals, meet regulatory commitments, or take advantage of government credits and incentives, a growing number of municipalities are installing new or retrofit high-voltage electrode boilers that are compact, economical, and produce no emissions.
This is, in part, due to technological advances in electric boiler design that increase the output to a level that rivals even large gas or oil-fired boilers. When utilized for district heating, electric-powered alternatives are sure to be a critical piece of the puzzle to meet future emission reduction goals.
Transitioning from High-Emission Gas and Oil-Fired Boilers
With district heating, besides the notorious greenhouse gasses carbon dioxide (CO2) and methane (CH4), natural gas-fired boilers and furnaces emit dangerous nitrogen oxides (NOx), carbon monoxide (CO), and nitrous oxide (N2O), as well as volatile organic compounds (VOCs), sulfur dioxide (SO2), and particulate matter (PM).
However, many facility engineers familiar with gas-fired boilers mistakenly believe that electric boilers cannot match the output of the traditional, fossil fuel burning units. Due to considerable advances in electric boiler technology, that is far from the case. Today, such technology can match the capacity of large gas or oil-fired boilers in a much smaller footprint.
Electric boilers utilize the conductive and resistive properties of water to carry electric current and generate steam. An A.C. 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. Crucially, almost 100% of the electrical energy is converted into heat with no stack or heat transfer losses.
As an example, the electrodes of the CEJS High Voltage Electrode Steam Boiler by Acme, a Canada-based manufacturer of industrial and commercial boilers, 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 6MW to 52MW.
The boiler operates at existing distribution voltages, 4.16 to 25 KV with up to 99.9% efficiency, and can produce up to 170,000 pounds of steam per hour. With pressure ratings from 105 psig to 500 psig, the boilers are designed to ASME Section 1, and are certified, registered pressure vessels at the location of the boiler.
“There is an entire generation of district heating facility engineers that grew up with oil and gas-fired boilers almost exclusively,” says Robert Presser, Vice President of Acme Engineering, which, along with North American facilities, builds in Europe to European standards and has a network of CE-compliant fabricators for the pressure vessel, as well as partners in France and the UK for local equipment assembly.
“As a result of preconceived notions, most view electric boilers as small underpowered units, like a hot water heater,” adds Presser. “So, we frequently have to educate engineers that there is electric boiler technology that can match the capacity of large gas or oil-fired boilers available.”
According to Presser, the electric boiler technology is used for residential and commercial district heating, which is increasing in demand, particularly within urban centers. With district heating, distributed heat is generated in a central location through an insulated pipe system, and utilized for high-efficiency, low-pollution, space and water heating. For central heating applications, electric boiler technology quietly supplies ample power for its compact size. This approach is currently being considered to install several 50MW steam boilers in the center of Manhattan, replacing gas-fired boilers to provide centralized steam to a number of buildings.
Typically, district heating upgrades are initiated due to high heating costs that customers find unaffordable, often due to expensive fossil fuels or an aging system that needs to be replaced. Increasingly, such upgrades are pursued to minimize environmental impact.
The upgrades often entail retrofitting or replacing boilers (the heat source) with cleaner, more efficient electric alternatives, along with the heat distribution network (pipes/ heat exchanger stations).
In addition, electric boilers have several advantages compared to oil or gas-fired boilers, including superior safety, ease of installation, faster start-up and shut down time, and quiet operation. Electric boilers do not have a high minimum operating level to make them immediately available.
“Electric boilers do not need an operator because if anything goes wrong, the breaker trips, preventing further escalation of the issue,” says Presser. “With gas burning boilers, however, any gas leak can increase the risk of an explosion. So, gas units must usually be continually monitored or periodically inspected.” He notes that state and municipal safety guidelines vary depending on boiler type and the expected frequency of inspection.
With electric boilers, the energy input as well as adjustment is also precise and virtually immediate. In contrast, increasing or decreasing the temperature in a gas fired boiler is a slower process because it takes time for the heat in the boiler to rise or dissipate before reaching the targeted output.
The electric units are also 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, it is easy to have a conversation next to one without having to raise your voice.”
As the EU and U.S. resolve to dramatically cut their greenhouse gases to combat climate change, the urgency for areas using district heating to similarly reduce their carbon emissions will only grow. In this battle to protect the environment before the global climate hits an irreversible tipping point, municipalities along with state and federal government, and the commercial sector must do their part. Fortunately, advanced, zero-emission electric boiler technology can be a readily implementable part of the solution.
For more info, contact Robert Presser at Acme Engineering rpresser@acmeprod.com; phone: 888 880-5323; or visit our website.