Boiler Blog | Nationwide Boiler Inc.

Deaeration of boiler feed water is primarily known to remove dissolved oxygen from the water, however, there are four additional advantages of utilizing a deaerator: (1) carbon dioxide removal, (2) improved operation, (3) improved heat transfer, and (4) energy savings. In this month’s edition of Boiler Basics 101, we review the importance of including deaerators as part of your boiler plant.

Corrosion in boilers from dissolved gases leads to reduced heat transfer and efficiency losses. Both oxygen and carbon dioxide, if not removed from the water entering a boiler, will cause corrosion. Dissolved oxygen will attach to the metallic components of a steam system and form oxides, or rust, on boiler heat transfer surfaces. If carbon dioxide is present with the oxygen, the two gases together can be up to 40 percent more corrosive than if they were acting individually. Removing non-condensable gases and limiting or avoiding corrosion will greatly improve heat transfer.

Deaerators also serve the purpose of pre-heating the water before it enters the boiler. This process saves energy by recovering flash and exhaust steam from plant returns, energy that would normally be lost to the atmosphere, and utilizing it to pre-heat the feedwater. This recovered steam can account for 20 percent of the fuel typically required to provide heat for that process. Pre-heating the feedwater will also greatly reduce the chance of thermal shock caused by the expansion and contraction of heating surfaces and will ultimately improve the operation of your boiler.

Deaerators and atmospheric feedwater systems both have the same purpose and are made up of several individual devices including feed pumps, a corrosion resistant receiver tank, and a control panel. A deaerator does its job by mixing steam with soft water inside a pressurized tank, removing oxygen molecules which are then vented into the atmosphere. Atmospheric feedwater systems are non-pressurized and perform the same function while operating at a lower (atmospheric) pressure. A notable disadvantage of operating at a lower pressure is that a lesser amount of dissolved gases are removed. Although atmospheric systems are more cost effective, process requirements will dictate which system is ideal for your application.

Overall, if boiler feed water is not properly deaerated, corrosion will occur, and a boiler will operate less efficiently with a higher possibility of facing costly downtime and boiler repairs. Nationwide Boiler provides new deaerators and maintains a rental fleet of deaerating boiler feedwater systems for both low and high pressure applications. Our systems range in size for boilers 24,000 to 225,000 lb/hr, and are configured one of two ways: a skid-mounted deaerator with feed pump stand or complete mobile feedwater system including the deaerator, feed water pumps, water softener, and chemical feed system, all pre-piped and wired and installed inside of a trailer-mounted van.  

Be sure to check out our previous Boiler Basics 101 blogs and stay tuned for the next edition!

Rental boilers are often overlooked as a necessity for many processing industries. However, in the midst of a crisis, the need for steam becomes much more apparent to the public eye. In the latest podcast episode from Inside the Boiler Room, ABMA President Scott Lynch discusses the rental boiler industry with Larry Day, Nationwide Boiler's President & CEO. Larry shares his insights on the world of rental boilers, which has significant relevance during the COVID-19 crisis with boilers near capacity at many hospitals and food processing facilities.

Larry and Scott discuss an array of topics, including the importance of rental boilers in times of crisis. As Larry stated, "Anytime there is a natural disaster, rental boilers are looked at almost like generators or air compressors. Steam is a utility, and that's where it comes in as an emergency condition. [Many businesses] need that utility to keep running." 

A rental boiler can provide added capacity for increased production needs or it can temporarily replace an existing boiler to keep a plant running. Specific information about the process must be known for the supplier to accurately quote a rental boiler application. This includes:  

•    (1) Boiler Size / Steam Capacity Requirement (typically in HP or lb/hr)
•    (2) Operating Pressure
•    (3) Saturated or Superheated Steam Need (if superheat, what temperature)
•    (4) Fuel Requirement
•    (5) Any Auxiliary Equipment Needs
•    (6) Emissions Requirements

Listen to the podcast now to learn more about rental boiler basics, the evolution of the rental boiler industry, and potential challenges with different technology and maintenance of rental boiler systems. Also, be sure to check out the ABMA’s Guideline for Rental Boilers, developed by members of the ABMA Rental Boiler Group, including Nationwide Boiler Inc.  

With the COVID-19 pandemic upon us, there has been a lot of talk about essential businesses. What is it that actually deems a business essential? In short, businesses that people rely on in everyday life are essential, while nonessential businesses are generally recreational in nature.

Many consumers may not understand the necessity of steam in everyday life, however, steam plays a major role in many industries including hospitals, food processing, refineries, and pulp and paper manufacturing. Let’s dive into exactly how steam is used in some of these processes.

Hospitals
One of the most obvious groups of essential workers right now are those in a hospital, and steam is utilized extensively in all hospital settings. There are five major uses of steam in a hospital: comfort heating, humidification of air, sterilization of surgical instruments and medical waste, laundry, and food preparation.  

Food Processing
Steam used by food processors commonly falls into two distinct categories: Clean Steam or Utility Steam. Clean Steam, also known as “sanitary” or “culinary” steam, is typically used for direct injection into a product or to clean and sterilize product contact surfaces. Utility Steam, also referred to as “plant” steam, can be used in most applications that do not involve direct contact with food products or the surfaces that the food might contact. It is often utilized to supply energy for heating, cooking, or mechanical work. 

Some other examples of where steam is typically utilized in food processing is the tomato canning process, deodorizing cocoa butter, puffing up cereal, and sanitization of yogurt cups.

Electricity Generation
Most of the electricity generated in the United States is from electric power plants that use a turbine to drive electricity generators, and many of these turbines are driven by steam. Steam turbines use high-pressure steam to rotate the blades of a turbine and create mechanical or rotational energy. As the steam turbine spins, the generator spins and creates electricity.

Pulp & Paper
Steam is used heavily in the production of paper products because energy drives the papermaking process. In fact, it is estimated nationally that steam accounts for approximately 43% of the total energy demand at a paper facility.

Most paper mills have a steam turbine to generate electricity. Steam is also used to cook wood chips and cook fibers for improved sheet strength, to evaporate moisture from pulp, to heat rotating dryer drums to dry the paper stock, and to heat chemicals for other processes. The steam from a boiler is also commonly used in other locations of the mill, like heat exchangers, steam-traced piping, and stock chests. Due to its usefulness, steam is the primary input used to evaporate moisture from a sheet, allowing for desirable and profitable sheet characteristics to be created.

Petroleum Refining
Petroleum refining is an energy-intensive process, with energy accounting for approximately 50% of refining costs. Steam is used in many ways in a refinery and is necessary to keep plants running.  Some uses include:

•   - Steam turbines for electricity generation and running pumps and compressors.
•   - Steam tracing and jacketing to keep viscous processes fluid in pipes.
•   - As a heating source to break up oils and distribute for the manufacturing of different products.
•   - As a heating source for lube oil systems for large pieces of equipment.
•   - As a heating source for reboilers.
•   - Plant cleanup.
•   - Stripper column injection to aid in stripping separation of different processes.
•   - Minor leak suppression by use of steam lances.
•   - Steam flares to aid in complete combustion of processes.

Chemical Processing
Steam also plays a large role in chemical processing and is used as both a process fluid and a utility. Common uses include process heating, power generation, atomization, cleaning and sterilization, moisturization, and humidification. Because it is so versatile, there are some major advantages to using steam in chemical processing:

• Control. By controlling the pressure of steam, you can control the temperature at which the heat is released. Having good control over the temperature is necessary in a number of chemical processes.
• Efficiency. Steam is an efficient heat source because it has a high output per mass of utility at a constant temperature.
• Safety. It is non-flammable, non-toxic, and inert to several process fluids.

Although steam is often hidden from our daily lives, it is the most effective way to transfer heat or energy and offers unique features that you just cannot duplicate with other systems. The simplicity and adaptability of steam makes it a reliable medium and first choice for many processing operations.

Nationwide Boiler takes pride in supporting many essential businesses with a reliable source of steam, whether for temporary or permanent use. As our own Walter Heussmann put it, “The heartbeat of America is driven by steam. The power industry, oil and gas, chemical, hospitals, food and beverage…. We are here to keep America going.”

Routine maintenance on your boiler is a critical component for proper and efficient boiler operation. One of the main factors to improper maintenance that can also lead to boiler failure is not understanding the concept of blowdown. In this month’s Boiler Basics 101, we will be going over what blowdown is and how it will help improve your boiler’s health.

When boiler water turns to steam, solids from the water are left behind. The blowdown process involves partially draining the boiler to remove the sludge those solids create. If these are not removed, boiler performance will be reduced and ultimately, it can lead to boiler failure.

Industrial boilers have three types of blowdown procedures:

• Low Water Cutoff
  This blowdown procedure should take place after every shift. The water column must be kept clean to ensure the water level in the gauge glass accurately represents the water level in the boiler. Regular checks on the boiler verifies that the low water cutoff is operating correctly and cleans it out.

• Bottom Blowdown
  Bottom blowdown is done by manually opening a set of two valves that drains water out of the bottom of the boiler. The purpose of the bottom blowdown activity is to clean out solids that accumulate at the bottom of a firetube boiler or in the mud drum of a watertube boiler. Solids are pushed through a blowdown separator designed to take water from the boiler during blowdown and reduce it to atmospheric pressure for disposal. During this process, steam is rapidly separated from blowdown water and vented out the top of the blowdown separator. From there, the cooled blowdown solids can be safely removed from the boiler.

• Continuous Blowdown
  The purpose of the continuous blowdown is to help control the water quality in the boiler; the more impurities and the more chemical treatment required, the greater the amount of blowdown required. It is a procedure facilitated by a pipe entering the upper section of the boiler, typically located in the steam drum of a watertube boiler or the upper steaming portion of a firetube boiler.

The continuous blowdown process is generally automated and does not require much manual interaction, like with bottom blowdown. When operating continuous blowdown, adjust the valve to maintain the recommended boiler water dissolved solids level. This helps control the dissolved solids in boilers that are operated at a steady load.

It is important to consider proper blowdown procedures to keep the water piping clean and the boiler in working condition. 

Be sure to check out our previous Boiler Basics 101 blogs and stay tuned for the next edition!