Fill out the form below or give us a call, (770)786-5555.

[contact-form-7 404 "Not Found"]
 

Skip to Content

Latest News & Insights

From the Mahans Thermal Products team.

The Beginner’s Guide to Absorptive Silencers

In an air-handling system, noise frequently originates from one of several sources, including fans, passage of air through straight ducts, and the impact of air flowing through components such as elbows, branches, and mixing boxes.

Several types of duct silencers may be employed to reduce noise, including absorptive or dissipative silencers, reflective or reactive silencers, diffuser or depressive silencers, and active noise control. We will examine the absorptive silencer.

0 0 Continue Reading →

Heat Exchanger Cleaning and Maintenance Best Practices

Heat exchanger shell and tube

Heat exchangers need to be regularly inspected, cleaned, coated, and maintained. Performing regular maintenance and upkeep on your units provides reduced downtime, improves energy efficiency, stronger outputs, saves money, and extends the life and worth of your equipment. Inefficient heat transfers can slow down and even stop entire operations. In the world of refineries and energy operations, especially, it is important to keep these units in prime condition.

0 0 Continue Reading →

The Engineer’s Guide to Sound Attenuation

The Engineer's Guide to Sound Attenuation

The risk of physical damage to human beings, domestic animals, and wildlife from noise is well documented. Temporary or permanent hearing loss may result from noise exposure of excessive intensity and duration.

Hazardous noise risks infographic

While the risks exist everywhere, the workplace is the primary environment for the potentially hazardous effects. It has been estimated that 14 million U.S. workers are exposed to hazardous noise.

0 0 Continue Reading →

Everything You Need to Know About Heat Exchangers

What Is a Heat Exchanger?

A heat exchanger is an important component in industrial sites. Heat exchangers are found in all different types of equipment, from air conditioners and diesel engines to smoke stacks. These pieces of equipment can be used for either heating or cooling but are used primarily in industrial applications for cooling. These exchangers transfer heat from one medium to another, often to prevent equipment or substances from overheating.

There are several methods that heat exchangers use to accomplish the task. These designs will have different flow arrangements, features, and equipment. The end goal, however, is the same. These heat exchangers function to directly or indirectly expose a warmer liquid or gas to a cooler one. This is generally accomplished using a series of tubes protected with casing and can be further assisted by fans, lines, coolants, and other components.

0 0 Continue Reading →

All About Heat Exchanger Repair

When it comes to heat exchanger repair, there are two important and interconnected approaches. Proactive heat exchanger maintenance prevents smaller problems becoming large, stop-work issues. Reactive maintenance can generally be prevented by consistent cleaning and maintenance schedules. However, issues do come up, and machines do go down.

Plate heat exchangers are intricate in design. If you are taking a reactive approach to maintaining your unit, you will be looking at a lot of downtime and huge costs. Consistent attention and adherence to maintenance schedules will save you money and time.

0 0 Continue Reading →

How to Design Heat Exchangers – The Step-By-Step Technique

How to design heat exchangers the step-by-step technique


The importance of heat exchangers infographicThe versatility of heat exchangers has made them a common sight in a wide range of industries, from power generation, to oil and gas, to food processing. And that’s not even to mention the place we see them the most on a daily basis – in heating, air conditioning, and refrigeration equipment.

Aside from the many applications they can be deployed for, heat exchangers are primarily designed to provide the most efficient heat transfer rate possible along with the lowest possible installation, operating, and manufacturing expenses. That’s why there are so many different types of heat exchangers, and why each individual heat exchanger is designed to fit a very specific need.

What a heat exchanger is called varies based on what it does. While shell and tube and plate heat exchangers are the types most often seen in large industrial plants, condensers, evaporators, heaters, and coolers are all present more often than we realize. Sometimes an air-cooled or custom heat exchanger is necessary to meet operational needs.

Bar graph divider graphic

What is the step-by-step design technique?

Blueprint papers and toolsA heat exchanger is a piece of equipment that utilizes service fluids to achieve a heat transfer process, and, no matter what it’s going to be used for, optimum design is a must. Thermal-hydrodynamic design is a step-by-step numerical design technique and is one of the most common methods of building heat exchangers of all kinds. Although this approach can be used with any heat exchanger, it is most precise for both the shell and tube and air-cooled heat exchange systems.

Engineers tend to prefer this step-by-step design approach because it allows them to attain the optimization goals they set. With this method, engineers divide the heat exchanger into smaller increments, essentially treating each section as an individual heat exchanger.

When dividing the machine into sections, operating concepts like pressure and temperature are seen as exit operating conditions for one section and inlet conditions for the next section. The same procedures are followed from one section to the next, as an engineer works his way toward achieving the desired final operating conditions.

By focusing on each increment of the device, step-by-step, the error in each section is minimized and, therefore, the accumulating error is less than would be possible with a less systematic method.

Bar graph divider graphic


The Advantages of the Step-By-Step Technique


Heat exchanger use quote graphicEssentially, there are two major advantages of the step-by-step heat exchanger design technique. By accounting for each individual section of a heat exchanger and its accompanying variables (pressure, temperature, etc.), a nonlinear fluid temperature along the flow path is eliminated, and so are all of the harmful effects, such as increased fouling and maintenance needs, that such temperature differences can cause.

The step-by-step design technique also bears in mind the change in thermal and physical properties that come with changing pressures and temperatures, which makes for a more optimally designed heat exchanger whose fluids can and will experience massive temperature differentials at both ends.

Engineers using this design method end up with a final product that offers these benefits and features an adequate amount of surface area on which heat can be transferred, all while cutting down on its overall manufacturing cost.

Bar graph divider graphic

A Design for Every Need

As precise as the step-by-step design method is, its greatness is in that it can be used on just about any type of heat exchanger. Shell and tube, plate, air cooled, water cooled, custom heat exchangers, condensers, and evaporators can all benefit from this technique in some way. Here, we will highlight some of the main uses and benefits of each type of heat exchanger to help you on your way to choosing and designing the right one for you.

Shell and tube heat exchangers.

Even with all of the other types that are now available, shell and tube heat exchangers still reign supreme (or, at least, in the heat exchanger market). Often found in power plants, oil refineries, and other chemical processing sites, shell and tube heat exchangers are everywhere and are ideal for this step-by-step design method.

Tube heat exchangerPlate heat exchangers.

Also known as plate and frame heat exchangers or flat plate heat exchangers, plate heat exchangers are known to be the most versatile available. As their name suggests, plate heat exchangers feature plates that sit side-by-side and have a gasket fitted between them that creates the space necessary for fluid to flow between ports.

The three main types of these systems are gasketed, brazed, and welded, each of which offers a variety of benefits over other heat exchangers, including a more compact design and higher heat transfer rate. Plate heat exchangers also make it easier to adjust heat transfer capabilities, as it only requires the adding or removing of plates.

Air cooled heat exchangers. When a cooling system is needed, but space is lacking, an air-cooled heat exchanger is often the heat exchange system of choice. Air-cooled heat exchangers often serve as an engine’s main cooling system and are also seen in most construction equipment and larger, commercial-duty lawnmowers. With an air cooled system, you also generally do not have to deal with the corrosion of metal parts and contamination problems as often as you do with water-based systems.

Closeup of heating deviceWater cooled heat exchangers.

Like air cooled heat exchangers, water cooled heat exchangers are also referred to as oil coolers. These devices often function as radiators, albeit radiators with exceptional thermal properties, and are used in forced-air heating and cooling systems and for liquid chilling, as well as many industrial applications. The ability to transmit heat over long distances without a major temperature differential and remove heat from one source and onto a cooling surface are a couple of major benefits provided by a water-cooled heat exchanger.

Custom heat exchangers. It is often the case that a building just does not mesh with the heat exchange system it needs. Whether it is an issue of the amount of space available or just dealing with a flat-out unusual space, sometimes the problem can be solved with a plate heat exchange unit that is made for small spaces, but, in others, it can be impossible to find an existing model that suffices.

In these cases, a custom heat exchanger may be the perfect fit and can provide a way to maximize both performance and efficiency. A custom heat exchanger’s uses are almost limitless, ranging from serving as a condenser and evaporator in air conditioning and refrigeration systems to being used as the radiator under the hood of a car (or even on electronics).

Outdoor heat exchangerCondensers and Evaporators.

When you think of condensers and evaporators, heating, cooling, and refrigeration systems instantly come to mind. While it’s true that they are used in most HVAC-R systems, they play many other crucial roles within industrial settings. In thermal power plants, condensers are used to condense the exhaust steam from a steam turbine. This process converts the turbine exhaust steam into pure water, which allows it to be reused for another purpose within the plant.

Evaporators are used extensively in the food and beverage industry. There are some consumable products that either need to have a specified consistency or have a long shelf life. To live up to these expectations, these foods and beverages must go through an evaporation phase during processing. Condensers and evaporators often go hand-in-hand, and a major design consideration is how to have them help you make better use of the resources you have.

Bar graph divider graphic

Design Considerations

Man working on machinery in factoryThe step-by-step method for designing heat exchangers is a great way to design a device with minimal errors and inefficiencies, but even the best design cannot be overcome if important factors are not considered. Since heat exchangers are useful in so many applications, there are a variety of things that need to be taken into account during the design process to ensure that the device you end up with fits your exact needs. With that in mind, here are a few factors to keep in mind so your new unit can live up to expectations.

Substances to be used.

It makes a difference which type of substances will be used in the heat exchange process, as those substances will be traveling through your machine all the time. For instance, a gas requires more surface area than another liquid. Therefore, a flattened tube that creates more surface area on the outside of the tube from which the gas is heated may be necessary.

Flow arrangement. The three main flow arrangements that heat exchangers are classified under are counter-flow, parallel-flow, and cross-flow. Counter-flow is the most efficient design, and it entails the fluids entering the unit from opposite ends and flowing toward one another. A counter-flow flow arrangement is so efficient because it transfers the most heat from the medium (typically liquid or gas) per unit mass because the average temperature along any unit length is higher.

Parallel-flow heat exchangers have both fluids enter from the same end and travel toward the other side of the device parallel to each other. Cross-flow is the opposite of parallel-flow, and one fluid in them travels perpendicular to the other through the heat exchanger.

Copper coilsTwin coils or basin.

The twin coil design uses two copper tubes that are coiled together to create a large surface within a compact system. Although using twin coils provides a compactness that has its own set of benefits, it is a poor setup for systems that utilize gas. A basin setup is often found in the air-to-air and liquid-to-air systems common in radiators and water heaters. One major advantage of a basin is that it can be used in heat exchange systems that involve gases and other harsh mediums.

Desired efficiency. One of the biggest considerations when designing a heat exchanger is how efficient it needs to be. A heat exchange unit with coils made out of cheaper metal or plastic is less expensive but not as efficient as those made with sturdier materials. A more efficient system will require coils that are greater in number and made with better materials – preferably a durable metal such as copper that has extensive heat transfer properties.

Stack of stainless steel tubesIdeally, you want a heat exchanger that is as efficient as possible, but, if the unit will be playing a more minor role in your facilities or your budget simply won’t allow for the purchase of a maximally-efficient system, there are other options.

Tube diameter, length, and thickness.

The tubes of a heat exchanger may be straight, bent, or in the shape of the letter U, but it’s the diameter, length, and thickness of those tubes that really make a difference regarding what to choose for your device. Tubes with a smaller diameter, while less expensive and more compact, are also more prone to fouling and harder to clean when certain fluids are used.

Often, a long tube length is chosen to make up for a small diameter, but this may be more trouble than it’s worth in the long run, as long, thin tubes are difficult and expensive to replace. Choosing the thickness of a heat exchanger’s tubes is generally a pretty straightforward process, as thicker tubes are typically used simply to ensure that there is adequate room for corrosion and to enhance axial strength.

Bar graph divider graphic

Conclusion

Designing a heat exchanger is no small task, and there are many variables to consider along the way. It all starts by deciding which type of heat exchanger you needs, and there are plenty to choose from, including custom-designed systems that can be made to fit any space and purpose.

Once you have decided on a particular type, take into account which fluids you’ll be using, the flow arrangement you need, whether to use a twin coil or basin setup, the efficiency required, and the ideal tube design for your given application. Once you’ve decided what you need and accounted for all of the details, both big and small, it’s only a matter of having it built.

Nothing in life or industry is perfect, but the step-by-step technique is the most sought-after design method in the industrial world because its end-product is a heat exchanger that comes as close to perfect as can be.

 

0 0 Continue Reading →

Everything You Need to Know About Basco Parts

Basco Type 500 heat exchanger

Basco is a name that has been in the heat exchange universe since 1953 when the shell and tube heat exchange manufacturer was founded in Buffalo, New York. In 1962, the company was acquired by American Precision Industries, forming what is now API Heat Transfer. Over the years, Basco has evolved to keep up with the latest technologies to stay at the forefront of the heat exchanger market.

0 0 Continue Reading →

Heat Exchanger Fouling

Heat exchanger in need of cleaning

While heat exchangers are incredibly durable and versatile devices, they are not immune to occasional problems – including fouling. Fouling occurs when undesirable material builds up on a heat exchanger’s surfaces and causes it to malfunction. There is a wide range of materials, both living and nonliving, that can cause fouling. Fouling makes a heat exchanger less efficient and can lead to long-term problems if not dealt with immediately.

Since fouling has the potential to slow down or disrupt operations altogether, it makes sense to know how to identify the most common types of fouling, when they tend to occur, and how to make them happen as infrequently as possible.

0 0 Continue Reading →

Industrial Applications for Plate and Frame Heat Exchangers

Plate type heat exchanger

Plate and frame heat exchangers are gaining in popularity faster than any other segment of the heat exchanger market. Part of the reason for the rising demand for plate and frame heat exchangers is that plates can be added or removed depending on what is needed, giving them an unprecedented versatility.

Plate and frame units got their name because they are made of corrugated plates on a frame—a design that produces a lot of turbulence and high wall shear stress, providing them with a high heat transfer coefficient and making them more resistant to fouling. The hot fluid in a plate and frame heat exchanger typically flows down one plate while the cool fluid flows up the other plate.

Plate and frame heat exchange systems are available as either brazed, welded, or gasketed, depending on your needs. They also offer many advantages, from taking up less floor space, to operating with small temperature differences, to simplifying the cleaning and maintenance processes.

As many benefits as they offer, the more important thing to focus on is what they do within the industries they’re used in. With that in mind, here is a brief summary of their capabilities within different industrial segments.

0 0 Continue Reading →

How Condensers and Evaporators Are Used in HVAC-R

HVAC system in industrial setting

Central air conditioning systems and refrigeration systems depend on a basic property of gases to make cooling possible, and condensers and evaporators are indispensable parts of that process. Evaporator coils and condenser coils, as their name suggests, are responsible for the evaporation and condensation phases that reduce gas pressure, which allows it to expand and then cool.

Condensers are responsible for condensing a substance and cooling it to take it from a gaseous state to a liquid state. In both air conditioning and refrigeration systems, an evaporator allows a compressed coolant such as Freon or Puron to evaporate from a liquid to a gas while absorbing heat along the way.

Here we’ll dig a little deeper into what exactly condensers and evaporators do and how they’re relevant the HVAC-R industry.

0 0 Continue Reading →