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HC2 Thermal Fluid Heaters

The HC2 Gas fired thermal fluid heater is available in standard sizes from 1 to 100 MM Btu/hr. Configuration options include vertical up-fired, vertical down-fired, and horizontal. Custom heater designs are also available to meet a wide variety of project-specific design challenges. Sigma Thermal also offers HC1 gas fired thermal fluid heaters, biomass-fired thermal fluid heaters as well as options for electric process SHOTS electric heaters.

If you already understand your needs, you can submit an RFQ here. If you have questions, contact an application engineer today.

Design Features

• Designed to meet all area classifications and to endure harsh environments, including offshore, arctic, and deserts
• Capacities from 1MM to 100MM Btu/hr – custom sizes also available
• Advanced control system options – Sigma Automation
• Double helical coil design for three passes of flue gas along conservatively designed coil surface area
• Base efficiencies can exceed 88% (LHV Basis) depending on process inlet temperatures, and with an optional economizer can exceed 93% (LHV basis)
• Flue gasses are significantly cooled, eliminating the need for most internal shell insulation
• Heater shell is externally insulated with mineral wool insulation and covered with aluminum cladding
• Standard or engineered burner configurations for use with both traditional and alternative fuel sources
• Low emissions burners available to meet all emission requirements

High-Pressure Steam Generators

The high-pressure steam generator produces non-toxic process heat.

NUK® High-Pressure Steam Generator

The NUK® High-Pressure Steam Generator is a closed-looped (hermetically sealed) system that produces steam for high-temperature applications. Therefore, this steam generator is able to produce non-toxic process heat while offering the same advantages of a conventional hot oil system.

Oil Deodorization

Sigma Thermal developed the NUK ® specifically for the application of oil deodorization, typically used within the food industry. During deodorization, the NUK is used as a heat source in the process to safely remove undesirable flavors and odors from edible oils; leaving the oil free from toxins.

Submit an RFQ – To specify your high-pressure steam generator.

Calendar Rolls

The calendering process of smoothing and compressing a sheet of material by passing it through a number of pairs of heated rolls is widely used in the manufacture of paper, textiles, and plastic sheeting to provide it with the desired surface finish and texture.

Pressures, temperatures, and dwell times play a significant role toward achieving a homogeneous surface with a superior finish. In order to guarantee consistent and uniform quality and properties, the correct roll temperature with the least amount of variance is vital.

Many calendar roll applications call for a high temperature, low pressure, hot oil system.  At Sigma Thermal, our application engineers can help you plan and design individual solutions that provide uniform heat distribution on the roll surface to guarantee a consistently high level of quality and uniform, even finish.

Edible Oil Deodorizers

Edible oil deodorizing is essential for removing undesired components such as moisture, color, and odor that negatively impact the taste, smell, and appearance of the final product.

Crude forms of edible oils are deodorized via steam distillation to evaporate all odor substances and leave the oil with a stable flavor profile.
Effective deodorization is a complex vacuum steam distillation process that involves using high-pressure steam to heat the oil to a precise temperature for stripping impurities and then cooling it to retain the natural oil characteristics. Closed loop, hermetically sealed, high-pressure steam systems that provide tight control over time and incorporate economizers to recover as much heat as possible from the hot oil ensure process stability and save energy. At Sigma Thermal, we have the expertise to design a robust and reliable high-pressure steam generator for your edible oil refinery line.

Indirect Steam Generators

Steam is the most widely recognized heat energy transfer mechanism and is capable of providing rapid and even heating for many large-scale industrial applications.

Steam is regularly used as a driving force in turbines and as a motive force to keep liquid and gas streams flowing. Process fluid heat exchangers, dew point heaters, reboilers, combustion air preheaters and many other types of heat transfer equipment frequently use steam as the heating medium.

Sigma Thermal offers a unique option for indirect steam generation that utilizes high-temperature hot oil and a customized heat exchanger.  In facilities that have several high-temperature users and that plan to use a hot oil system in addition to steam, the need for a separate fuel-fired boiler can be eliminated. This configuration can also be advantageous areas that may not require licensed staff for operation due to the indirect nature of the generation.

To learn more about the heat exchanger or the hot oil system option, contact our process heating experts. Our team will ensure that you get a custom engineered solution that integrates fully into your plant environment.

Presses

The combination of heat and mechanical pressure is frequently an integral part of many manufacturing processes.

Press platens are designed with channels and pathways that allow for a heat medium to pass through, deposit, and transfer its energy through the platen to the product within. OSB, MDF, and melamine line presses are common within the wood products industry. Fossil fuel-fired and biomass-fired hot oil systems are commonly used in combination with high flow secondary circulation loops to minimize platen thermal gradients.  The use of hot oil within the biomass system permits high operating temperatures at relatively low design pressures.

Dryers & Kilns

From biomass combustion to the preparation of materials for lumber and engineered wood production, drying biomass is often a central process in wood products manufacturing.

Biomass dryers come in a variety of configurations, and heat energy systems often need to consider many plant-specific variables to obtain maximum energy and throughput. Lumber kilns also use a variety of heat energy sources, and every individual facility and wood species will have their own specific needs.  Natural gas or fuel oil serve as a primary energy source, but it is also very common to burn wood waste from the plant to either supplement or entirely replace the need for fossil fuels.

Biomass Fired Systems are complex, and it is imperative that fuel handling, combustion control, ash removal, and waste heat recovery systems be designed to give operators maximum combustion quality with clean emissions. Sigma Thermal engineers are heat energy management experts. We optimize our heating systems to provide the most cost-effective operation possible and provide energy audits to ensure that recovery potential is fully realized.  Whether considering a traditional fossil fuel-fired system, or a biomass-fired system, Sigma Thermal has the applied engineering expertise to ensure your facility’s potential is fully realized.

Liquid-Gas Vaporization

Many gas products (hydrocarbon and non-hydrocarbon based) are transported and stored at low temperatures. 

The liquefied product must then return to its gaseous state to be fed into transmission and distribution grids. Common examples of these products are propane, butane, nitrogen, oxygen, and liquefied natural gas.  There are several liquid-gas vaporization methods used. Selecting the optimum process depends on plant site location, climate conditions, and throughput capacities.

The vaporizing process typically takes place at high pressure using a series of heat exchangers to gradually warm the liquefied gas until its temperature rises above 0°C.

Depending on environmental conditions, various thermal fluid systems using glycol-water, hot oil, or hot water are all options for heating the gas to the desired temperature. With today’s high energy prices and concerns over the environment, closed-loop recirculation systems and waste heat recovery play an important role in conservation efforts for this and other gas production processes. Our engineers are experienced with a range of alternative solutions and offer insight into which is best for your application.

Plant Utility Heating

Sigma Thermal designs and manufactures process heating systems that support plant utilities such as steam systems, compressed air, and cooling towers, delivering reliable heat for both processing operations and industrial space heating. Our custom systems can draw on different power sources, including fossil fuels and biomass, to fuel boilers or heaters, distributing that heat efficiently through a simple or intricate network of insulated piping to reach rooms and equipment as needed.

What Is Plant Utility Heating?

Plant utility heating systems generate and distribute heat across multiple building and operational functions. They can power general climate control, support process applications like batch material heating, and supply steam for cleaning operations. These systems can also preheat boiler feedwater, improving overall energy efficiency and responsiveness across the manufacturing and processing systems they serve.

Common Applications for Utility Heating Systems

Industrial facilities rely on utility heating systems for dozens of applications throughout daily operations. When you work with Sigma Thermal, we conduct a thorough review of your facility’s use cases to design a versatile heating solution engineered around your specific needs. Some of the most common applications include:

• Boiler feedwater preheating. Preheating boiler feedwater reduces the energy required to bring water up to operating temperature, lowering fuel consumption while reducing thermal stress and wear on boiler components over time.
• Wash water heating. Utility heating systems supply hot water for sanitation tasks such as cleaning tanks, vessels, and processing equipment, supporting hygiene and regulatory compliance in food, beverage, and pharmaceutical operations.
• Freeze protection. Circulating heated fluid through piping networks and equipment prevents freeze-related damage in cold climates, protecting critical infrastructure and avoiding costly downtime.
• Indirect steam generation. Using a thermal fluid system or indirect steam generator, plants can produce steam at multiple points of use rather than relying solely on a single central boiler, improving distribution efficiency and adding redundancy across the facility.
• Building heat. Utility heating systems provide reliable climate control for facility spaces, maintaining safe and comfortable working conditions for personnel and equipment.
• Combustion air preheating. Preheating combustion air before it reaches burners, turbines, and industrial boilers improves combustion efficiency, reduces fuel demand, and lessens wear on specialized heating equipment.

A well-designed plant utility heating system supports these applications simultaneously, often from a single thermal fluid loop, delivering more energy-efficient operations across the facility.

Direct vs. Indirect Heating: What’s the Right Call for Your Application?

Sigma Thermal creates custom industrial heating systems that accommodate different equipment and levels of demand. Our process heating systems can be sorted into two main categories: direct heating and indirect heating.

Direct-Fired Heating System

Direct-Fired Heating Systems

Direct-fired heating systems are cost-effective and deliver consistent heat output for single-point applications in which the process fluid can be routed directly through the heater. A direct-fired air heater uses a burner to generate hot combustion gases that transfer heat directly to the process fluid as it flows through coils inside the heater vessel, without an intermediate heat transfer fluid or secondary loop.

Direct-fired systems can be configured for convection or radiant heat transfer, or a combination of both, depending on your process requirements, and their heat-generation capacity can be sized and customized for the specific application.

Sigma Thermal’s design and engineering team can help you determine whether direct heating is the right fit for your application, whether a single-burner or multi-burner configuration is best, and which furnace burner style suits your process conditions.

Indirect Heating Systems

Indirect heating systems are more flexible and can serve multiple applications simultaneously, even when those applications are sensitive or require different heat levels at different points in the process. Indirect heating options include process bath heaters and thermal fluid heaters.

Indirect heating uses a closed-loop system in which a heated thermal fluid medium, such as steam, oil, or water/glycol, is generated at a central heater and then circulated to multiple locations for downstream use. This makes it well-suited to applications such as preheating combustion air and supporting process reboilers.

Once you’ve determined that indirect heating is the right approach for your facility, the next step is selecting a thermal fluid medium. Steam is inexpensive and efficient, and it can be superheated to very high temperatures, but it must be contained within high-pressure-rated systems. Thermal oil can reach temperatures up to 750°F, and water/glycol solutions can reach up to 350°F under the right conditions, both without requiring high-pressure-rated equipment.

Increase Efficiency with Waste Heat Recovery

One of the biggest advantages of a plant utility heating system is the ability to recover waste heat that would otherwise be lost. Exhaust from turbines, fired heaters, and other plant processes is often hot enough to carry real, reusable energy, yet it’s typically vented, or worse, actively cooled and dispersed at additional cost.

A closed-loop liquid-phase heat transfer system captures that excess energy at the source and puts it to work in lower-temperature applications like preheating water, space heating, or process preheat. Here’s how it works: a gas-to-liquid heat exchanger pulls heat from the exhaust stream and transfers it into a closed-loop thermal fluid. That heated fluid then circulates to one or more downstream heat consumers throughout the plant, with no additional fuel burned and no process interruption.

For facilities actively cooling exhaust heat before dispersing it, this represents energy you’re paying to lose twice: once in the fuel that generated it, and again in the equipment used to cool and disperse it. Even facilities simply venting exhaust to atmosphere are leaving that same energy on the table, unrecovered and unused.

Sigma Thermal designs custom waste heat recovery systems, selecting the optimal layout, heat exchanger configuration, and heat transfer fluid for your facility’s specific exhaust conditions and downstream heat demand, to deliver more energy-efficient, cost-effective operations.

Engineer the Right Utility Heating Solution

Sigma Thermal specializes in efficient, innovative plant utility heating solutions, including direct-fired heaters, indirect heating systems, and industrial waste heat recovery options. Contact us today to discuss a tailor-made heat solution for your plant, or request a quote for pricing details.

Seal Gas Heating

In centrifugal compressors, a dry gas seal is used to prevent leakage of the process gas into the environment.

Typical dry gas seals have a tandem configuration, providing a back-up seal should the primary seal fail. These seals operate at high pressures using a high purity seal gas. The high pressure gas injected into the seal must be heated to prevent condensation from entering the seal as well as to ensure that the gas does not condense once it has entered the seal. If the gas condenses, the pressure in the seal will be lost and process gas can escape.

Sigma Thermal produces precision high pressure heaters, which average 10 kw to 30 kw, for seal gas applications. Heaters are typically constructed of stainless steel and designed to provide the high quality dry gas required for operation of this type of seal. With industry leading experience and engineering knowledge, we offer both stock and custom designed industrial heating products that are used in a variety of demanding applications.