Process Heat

Process Heating

Welcome! Below you will find an introduction to process heating. Whether you are a seasoned professional within the industry or someone who is looking to acquire their first heat processing tool, our process heating guide will help give you a rounded view of process heating and how the team from Heatgun.com can supply you with the largest selection of LEISTER tools, parts, and accessories.

How to use this guide?

1. Get fully educated and read the whole darn thing.
2. Select the topic you are interested in learning more about and get transported through a click of a button to that specific process heating section.[1] 
1. What is process heating?
2. Types of process heating systems?
1. Fuel
2. Electric
3. Steam
4. Hybrid
3. Best Practices on How to Save Energy Now in Your Process Heating Systems
4. How to Reduce Heat Loss in Process Heating Systems
5. Energy Consumption and the Value Process Heating Provides
6. Features of Process Heat Systems
7. Uses of Air Heaters for Process Heating
8. Industrial Process Heating: How does it improve processes and save money?
9. Process Heat: A solution in global climate science and environmental clean-up
1. Global Climate Science - Part 1
2. Global Climate Science - Part 2
10. How to Choose the Best Process Heater
11. How to Choose the Best Air Blower
12. Why is Leister a premium product worth investing in?
13. In-closing, a vital perspective on process heating

What is Process Heating?

What do steel, paper, food, paint, and jewelry all have in common? They are a small sample of materials and products that depend on process heating for production. Process heating is necessary in almost all manufacturing processes that produce basic materials and products, and it’s used throughout industry – from the smallest manufacturing companies to the huge Fortune 500 companies.[1] In the U.S. alone, more than 300,000 establishments contribute to the employment of an estimated 16 million people, which are directly or indirectly, affected by process heating.[1] Nearly 17% of all energy used by industry comes from heating processes.[1] In some specific areas of industry, such as the glass industry, process heating accounts for about 80% of energy consumption.[2]

In process heating, heat is applied to raise the temperature of solids, liquids, or gases in heating equipment (e.g. furnaces, process heaters, melters, ovens, and dryers).[3] The heating process softens, melts, or evaporates materials, and may promote chemical reactions, molecular rearrangements or breakdown of molecules of the materials being heated. Heat required in process heating equipment comes from [3]

• natural gas
• fuel oil
• coal
• electricity, and
• steam.

Types of Process Heating Systems

There are four process heating systems, which are fuel-based, electricity-based, steam-based, and hybrid-based systems.

• Fuel-based process heating. Heat is generated by the combustion of solid, liquid, or gaseous fuels, and then transferred to the material, either directly or indirectly. In direct heating, combustion gases are in contact with the material, and in indirect heating, combustion gases are confined and separated from the material.

Fuel-based systems include furnaces, ovens, heaters, kilns, and melters.

• Electric-based process heating. Electric currents or electromagnetic fields are used to heat materials, either directly or indirectly. In direct heating, heat is generated within the material by

1. passing an electrical current through the material,
2. inducing an electrical current into the material, or
3. by exciting atoms/molecules within the material with electromagnetic radiation (e.g. microwave).

With indirect heating, one of three methods are used to heat a heating element or susceptor that transfers the heat by conduction, convection, radiation, or a combination of these to the material.

Electric-based systems include induction heating and melting, electric arc furnaces, infrared ovens, and vacuum furnaces.

• Steam-based process heating: Steam is used to supply heat to the materials, either directly or indirectly. In direct heating, steam is injected into liquids or gases. With indirect heating, a heat exchanger is used to cool and condense steam in tubes; the heated tubes supply heat to the liquids and gases. There are several advantages to steam-based process heating, such as high treat capacity, ease of transport, low toxicity and cost, and it can be generated by a variety of by-product fuels.

Steam-based systems include distillation columns, water or air heating, paper drying, and humidification.

• Hybrid-based process heating: A combination of process heat systems using different energy sources is utilized to optimize energy use and increase overall process thermal efficiency.

Examples of hybrid systems are hybrid boiler systems combining a fuel-based boiler with an electric-based boiler, and a paper drying process that combines electric-based technology with a fuel-based dryer.

Here at Heatgun.com, we provide all of these heating systems. Our objective is to deliver the best solutions to our clients. We apply sound principles of business management and inventory control, and we thrive on building long-term relationships with our clients including what process heating system you should get, buying it, and then providing service centers around the nation that offer FREE repair inspections on all our Leister equipment with 24-hour service turnaround (in almost all instances).[2] 

Best Practices on How to Save Energy Now in Your Process Heating Systems

According to the U.S. Department of Energy, there are several ways to save energy in process heating systems and possibly reduce energy use and costs by as much as 30%, and those ways include:[2]

• Control the air-to-fuel ratio
• Preheat combustion air
• Use oxygen-enriched combustion air
• Improve heat transfer with advanced burners and controls
• Improve heat transfer in the furnace
• Preheat fluid or load
• Use heat cascading
• Use fluid heating or waste heat recovery boilers
• Use absorption cooling
• Use organic Rankine cycles to produce electricity
• Install high-turndown combustion systems
• Use programmed heating temperature setting for part-load operation
• Monitor and control exhaust gas oxygen, unburned hydrocarbons, and carbon monoxide
• Use furnace pressure controls
• Locate sensors correctly

How to Reduce Heat Loss in Process Heating Systems

In industrial process heating equipment, 15% to 85% of the supplied energy is used, but the rest is often lost.[2] Reducing or eliminating heat losses is the most important consideration in saving energy. However, if it’s impossible to reduce the losses, it should be considered to recover part of the energy lost and use it within the process itself or for other useful purposes, such as converting it to easily transportable energy such as electricity.[3]

Here are some useful steps to reduce heat loss:[3]

• Reduce excess air used for fuel combustion in burners.
• Minimize air leakage by reducing size and number of openings and controlling pressure.
• Employ heat cascading: use high-temperature exhaust gases to supply heat to lower temperature heating processes.
• Repair and maintain insulation and refractories used for the walls and doors.
• Avoid use of water-cooled parts in furnace.
• If cooling is necessary, insulate the water or air-cooled parts.
• Minimize idling time for the furnace and ovens.
• Conduct regular inspection and energy assessment for the large energy use equipment.

Energy Consumption and the Value Process Heating Provides

Nearly one-third of the nation’s total energy use is consumed in U.S. industrial facilities, and process heating accounts for 36% of the total energy used in industrial manufacturing applications.[2]

Process heating systems include combustion systems that run on fossil fuels and biomass, electric systems, and heat recovery and exchange systems; about 90% of process heating energy comes from the combustion of fossil fuels, while electricity supplies the rest.[2] There are many factors that determine the energy efficiency of a process heating system, such as process temperature (temperature range in process heating is 148°C [300°F] to as high as 1648°C [3000°F]), equipment design and operation, and the type of heat recovery systems used.[1] Advanced processes, improved designs, and thermal efficiency gains are helping to reduce the environmental impacts of combustion-related emissions.[2]

The results of process heating are boundless in the industrial processes and production. Due to the vast size and scale of industrial heating use, there is a unique opportunity for renewable resources that could save significant amounts of energy.[1] With the use of advanced technologies and operating practices, process heating energy consumption could be reduced by an additional 5%-25% within the next decade.[1]

Features of Process Heat Systems

There are several different types of process heat systems used throughout industry. However, what they all have in common is that heat energy is used to create a product or produce a result.

Process heating systems are made up of four components:[5]

• Devices for moving heat from the source to the product
• Devices for generating and supplying heat
• Devices for recovering heat
• Devices for containing heat, such as heaters, furnaces, kilns, and ovens

Additionally, process heating systems can include varying support systems, such as sensors and controls, material handling, process atmosphere supply and control, emission control, safety, and other auxiliary systems.[1]

Uses of Air Heaters for Process Heating

The uses of air heaters for process heating are bountiful, as seen in the below examples.[6][7]

• Drying and heating of various things, such as paint, varnish, or damp wood. In the paper industry, freshly printed paper is often dried with hot air after printing to ensure high print quality while enabling faster processing speeds.
• Thawing frozen water pipes.
• Accelerating mixing process and dissolving foams which can arise during mixing and filling.
• Smoothing the coating on pills, putting a shine on chocolates and other types of candy, and cosmetic articles.
• Activating and dissolving solvent-free adhesives and melt adhesives. 
• Separating and fusing of synthetic fibers and fabrics, which include polyester, acrylic, nylon, rayon, and spandex.
• Sterilizing of packaging materials, such as bottles, corks, and containers.
• Shrinking of heat-shrink sleeves, films, tapes, solder sleeves and moulded parts. In the brewing and beverage industry, shrinkable plastics are increasingly replacing metal caps.
• Soldering copper pipes, solder joints, and metal foils.
• Welding thermoplastic materials. In the automotive industry, welding is used to attach interior panels and plastic trim.
• Ignite wood shavings, paper, coal, or straw in furnaces.

Industrial Process Heating: How does it improve processes and save money?

Industrial process heating is vital in achieving important materials transformations, such as heating, drying, curing, and phase changes, that are fundamental operations in the manufacture of most consumer and industrial products including those made of metal, plastic, rubber, concrete, glass, and ceramics.[4] Overall, process heating improves processes by providing efficiency in both small-scale and large-scale situations. For example, imagine trying to remove floor adhesive with just a putty knife or scraper; this could take a lot of manpower, energy and time. Process heating will decrease the time and effort put into the adhesive removal, which can save labor costs. A large-scale example that shows the efficiency of process heating is an industrial plant located in a very cold climate. Process heating systems protect equipment and materials from freezing cold temperatures, thus keeping them operational and preventing any unnecessary costs from occurring.

Process Heat: A solution in global climate science and environmental clean-up

Global Climate Science - Part 1

In freezing cold weather, scientific equipment can be rendered useless, but process heating can quickly and easily ensure that the equipment remains optimally functional. For example, the Steward Observatory located in the Pineleno Mountains of southeastern Arizona was experiencing useless barometers, anemometers, and other outdoor sensors due to the below freezing temperatures. They even faced the possibility that their large binocular telescope could be damaged due to falling ice.

What they needed was a compact item that produced a continual stream of controlled, focused hot air throughout the weather mast to prevent buildup of snow and ice. Not only would the air heater need to be compact, it also had to work well in temperatures as low as -20°C ( -4°F) and be controlled remotely. The Leister Hotwind System was the perfect solution!

Within hours of using the Hotwind System, the weather masts were nearly completely ice-free, and all the equipment was back up and functionally normally. Now, the observatory uses multiple Hotwind Systems to ensure all the equipment is always protected from icy temperatures.

Global Climate Science - Part 2

In Alaska, process heating was instrumental in an environmental clean-up situation. The shores of Togiak Bay faced an enormous environmental catastrophe when diesel and gasoline were spilled. Even after years of effort in cleaning up the spill site, there were still issues with contaminated soil. In a remote 5-acre site, a fishery decided to sell their establishment but had to come up with $812 million in clean-up costs. Not only was the cost very overwhelming, but due to no easy-access roadways, all equipment had to be flown in or shipped by barge.

An older technique for cleaning up contaminated soil utilized a heating system with an open flame to boil off the water. The process of boiling the water resulted in releasing harmful chemicals and contaminants into the air, and then the air needed to be “scrubbed.” The cost for this process was estimated at $12 million. However, with the use of Leister heaters and soil ovens, which became part of a patented treatment system, the contaminated soil was cleaned at two-thirds of the original quoted cost, and there was no need to “scrub” the air because the temperature of the heat was controlled, thus ensuring no harmful contaminants filtered into the air.

Thanks to Leister heaters, the environmental clean-up became more efficient and effective all at a much lower cost.

How to Choose the Best Process Heater

When deciding on the best process heater for your needs, consider what exactly you need to accomplish. Though all process heaters produce heat through a fuel-based, electric-based, steam-based, or hybrid-based system, the result of the system varies. Ask yourself if you need a process heating system to move heat from the source to the product, a system that generates and supplies heat, a system that recovers heat, or system that contains heat. Process heating systems can help you with your needs - everything from drying and thawing, to smoothing and sterilizing, to shrinking and soldering, to dissolving and fusing. You just need to determine your specifications and expected results, and the process heater will do the rest.

How to Choose the Best Air Blower

Hot air blowers can be used for various applications ranging from heating a space to drying coatings and parts, or from de-flashing plastic components to heating parts in manufacturing process.

When choosing a portable hot air blower, there are four main factors to consider:

• On-board thermocouple, which measures temperature
• High or low volume air flow
• On-board temperature control, which are always paired with the thermocouple
• Compatibility with air sources, such as a heater

Why is Leister a premium product worth investing in?

Leister products are worth the investment because of their worldwide market leadership. With over 130 sales and service centers in more than 100 countries, Leister can easily provide assistance at your location. Not only does Leister come to you, but they also offer products developed according to your individual specifications.

In addition to Leister’s high quality customer service practices, they have an extensive product range based on decades of experience in plastics processing and in industrial processes. To stay current, they continually develop and optimize their products to ensure prime quality, reliability, performance, and cost-effectiveness. The application laboratory is equipped with the most up-to-date measuring equipment and is well-suited for simulating applications and processes, thus allowing for a fast and efficient solution if needed. Furthermore, Leister ensures top quality and safety of all their products through independent testing.

Leister is committed to quality assurance, which includes complying with ISO 9001 quality standards, product-specific standards (e.g. ISO, IEC, EN and UL standards), and application-specific standards. To ensure client protection, tests are carried out by accredited and independent test institutes, and the products are certified and qualified to carry the conformity marking.

With Leister’s dedication to their industry and to their customers, it is well worth investing into their products.

Process Heating, A Vital Perspective

Process heating has been vital in the manufacturing industry, as it aids in the production of everyday commodities and basic materials. However, process heating is beneficial beyond the creation of products; it is beneficial in the creation of results and lowering costs.

• Need to dry parts or coatings? Hot air is the answer.
• Need to de-flash plastic components? Hot air is the answer.
• Need to thaw frozen metals or equipment? Hot air is the answer.
• Need to sterilize materials? Hot air is the answer.

The benefits that process heating can provide you are limitless, and no matter how extreme your needs are, you can count on our process heating technology and innovative products to meet your individual specifications. If you need help in deciding what product is best for you, talk with a Leister expert by emailing us at info@heely-brown.com or calling us at 1-800-241-4628. We would love to help you with all your process heating needs!