Steam Superheating

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Superheated steam is produced by the addition of heat to saturated steam, and it possesses properties that approximate those of a gas rather than a vapor.

Its value typically lies in the tremendous internal energy that can be used for propulsion/drive applications, such as turbines, while remaining above the condensation temperature of water vapor. Superheating ensures that the steam flow through a turbine or engine always remains a compressible gas that will not condense.

Sigma Thermal offers several types of systems that can provide steam superheat.  Direct heating options include Convection heaters, Radiant-Convective heaters, and Electric Circulation heaters.  Indirect heating options include hot oil and salt bath systems.  Whatever your use for superheated steam may be, Sigma Thermal can help you design a solution that best fits you process needs.

Ammonia Heating

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What Is Ammonia Used For?

Ammonia is commonly utilized in the agriculture industry as fertilizer. In fact, the ammonia produced for use as fertilizer accounts for about 80% of all ammonia industrially manufactured. This versatile substance may also be employed as a refrigerant gas or be used to purify water. Additionally, ammonia is often used in the manufacturing processes of a number of different materials, including plastics, fabrics, pesticides, dyes, and other chemicals.

From its gaseous state, ammonia can be easily compressed to form a clear and colorless liquid. In order to transport ammonia for industrial use, pressure is usually applied to create a liquid, and then this is shipped in steel cylinders.

Why Does Ammonia Need to Be Heated?

While being transported and stored in specialized steel cylinders, liquid ammonia is kept at about -30°F (-34.4°C) . Before ammonia can be loaded into agricultural trucks for distribution and use as fertilizer, the ammonia must be heated to about +40° F (4.4°C).

Why Is Reliable, Consistent Ammonia Heating So Important?

Heating ammonia is critical for ensuring effective use in the agriculture sector. Since there are only two growing seasons every year, there is a short window of time to load and distribute ammonia. During this period, high reliability is imperative; typically, a great deal of preparation is done prior to the growing season to ensure the efficient heating and distribution of ammonia.

There are a few common challenges associated with heating ammonia, however, such as low temperatures causing the water in flue gas to condense. This water must be continuously accounted for and removed. Additionally, flow rates may vary depending on how many trucks are being loaded simultaneously, and the heat input, or “flux rate,” must be controlled to avoid vaporization, or “flashing,” of the ammonia. If ammonia is vaporized, it must be returned to storage and recompressed.

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Ammonia heating is a delicate, essential process and must be conducted with great care to allow for effective utilization in the agriculture industry.

Sigma Thermal is proud to be a trusted source for streamlined, reliable ammonia heating. To learn more about our ammonia heating services and discuss options for your specific application, request a quote from the team today.

Freeze Protection

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Freeze protection is critical to a variety of industrial processes; from protecting water storage tanks to keeping heavy equipment operating during cold weather.

At Sigma Thermal, we engineer and fabricate a wide range of freeze protection solutions. Because our systems utilize heated fluid rather than electric heat trace cable, they can be applied to remote or low power applications.

Depending on the length and other parameters of the specific application, freeze protection systems may be electric or gas fired. Since these systems are not required to operate at extremely high temperatures, low pressure heating systems can be used, offering additional safety and simplicity. Fluid freeze protection systems can also be used in applications for which electric heat trace is not a viable option. For example, long runs of pipe and remote locations, and fire water tanks with limited power resources are all situations in which electric trace systems are less than practical, but fluid systems excel. Because these systems may be run for long periods of time, depending on the geographical location of the facility, we always places an emphasis on efficiency to minimize the operating costs of the heating system while still providing the necessary degree of freeze protection.

Viscosity Reduction

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Sigma Thermal has been working with the oil & gas industry for many years, providing innovative heating solutions for many challenging applications.

We have developed a number of system designs for the purposes of heating heavy liquids, such as crude oil or crude oil derivatives. This process is often performed to reduce viscosity, and in turn increase the mobility of the fluid. Pumping heavy crude oil requires significantly more power when the oil is cold and viscous. Heating the oil to reduce the viscosity makes the oil much easier to handle. However, overheating crude oil can degrade the quality of the product, so care must be taken not to scorch the oil during viscosity reduction.

With the use of indirect heating, the oil is heated via a heating medium; it is never in direct contact with the tube wall, which ensures the oil does not become overheated. Because heating is required adjacent the well, skid systems can be employed which allow for applications in remote locations. These systems are designed to tightly control temperature, minimizing oil degradation and bring new levels of efficiency to this critical application.

Direct heating of oil is also a common approach, and if managed properly can also be a good solution for heating crude oil.  Low watt-density electric heating elements, and convection only style direct fired heaters are excellent ways to mitigate unintended degradation.

Molding & Extrusion

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Precise temperature control is critical to the final quality of molded or extruded components.

Not only must the resin be held at a specific temperature, the mold or extruder screw must be properly heated to produce accurate parts. Among temperature control options, closed loop thermal fluid systems are ideal for these applications, as they constantly monitor temperatures and are able to adjust heating and cooling rates based on feedback from the system. Thermal fluid systems are also safer to operate because they function at low pressures rather than the high pressures required by steam-based thermal systems.

Ovens & Fryers

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For optimal efficiency, heating systems used in industrial food processing, such as ovens and fryers, must provide consistent, uniform temperatures to maximize quality and yields.

With the rising cost of energy, food processors are seeking ways to increase thermal efficiency to protect the already tight margins in this very competitive marketplace.

For industrial ovens, heating clean air and circulating it at tightly controlled temperatures maximizes throughput while improving the taste, texture, and appearance of baked goods. Temperature consistency in fryers provides the same benefits as in ovens and allows for reduced oil usage, further enhancing efficiency, and reduced oil degradation, preserving high quality taste.

Sigma Thermal systems are used in many food processing applications which require an efficient heating system. These systems utilize oils for heat transfer; this means higher operating temperatures—generally up to 600°F with organic, FDA approved thermal oils. They also provide a greater measure of safety as they operate at lower pressures than other heating technologies, such as high pressure steam.

Sigma Thermal specializes in engineering complete heating systems for food processing applications.  In continuous baking oven applications, we utilize multiple precision-controlled thermal zones that increase oven flexibility and control. When it comes to heaters and heating system control, Sigma Thermal can engineer a high efficiency solution that takes full advantage of cutting edge processes and advanced heating technologies.

Tank & Suction Heating

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Tank heating systems are key components for flow control, viscosity consistency, and protecting against frozen and broken pipelines. Energy efficiency and accurate thermal control are vital for maintaining process and material integrity, and Sigma Thermal manufactures process heating products in multiple configurations for tank heating and suction heating applications.

Suction heaters, designed specifically to heat material only as it is withdrawn, save substantial energy costs since overall heating requirements are considerably reduced. Sigma Thermal immersion heaters operate at near 100% efficiency while energy oil and water-glycol thermal fluid systems obtain high efficiency, especially at elevated temperatures for extended periods. Thermal fluid systems can be utilized in conjunction with immersion heat exchangers to provide a plant-wide tank heating solution. With decades of experience, Sigma Thermal engineers can guide you through the process of determining the optimal and most cost-effective system for your individual application.

Types of Tank Heating

Depending on your application’s requirements, there are two main types of electric tank heating available.

Direct Tank Heating

In systems using direct tank heating, the heater is in direct contact with the medium it’s heating. This is accomplished by either placing the heater directly inside the tank or circulating the fluid through the heater. The benefits of this type of heating include nearly 100% efficiency, accelerated heating, and the elimination of thermal lag. Subsequently, the system doesn’t involve any intermediate heat transfer medium that might otherwise cause a reduction in heat. 

Indirect Tank Heating

Unlike the direct method, indirect tank heating uses a heat transfer medium to avoid direct contact between the heater and the heated medium. You have the option of using the tank wall as the heat transfer medium in these systems. One of the key advantages of indirect heating is that you can service the tank without any need to drain it beforehand. Additionally, you can reduce the exposure of watt density to the process fluid by more evenly spreading the heat across a greater surface area.

Direct & Indirect Tank Heating Products

There are a couple of different types of electric tank heating products that you can use. 

Electric Immersion Heaters

One type of tank heating system you can install is an immersion heater. These heating systems require direct contact with the heated medium, which could consist of different types of liquids. These liquids may include water, viscous materials, solvents, oils, process solutions, and certain types of gases. Immersion heating systems also come with various temperature control options.

Electric Circulation Heaters

Another direct heating system you can use is a circulation heater. In these heating systems, the heater circulates the process fluid through the heater using either natural convection or a pump. Through the use of circulation heating systems, you can reduce watt density by spreading heat over a large heating surface. These are the ideal choice when there are space or watt density limitations. Circulation tanks can also be serviced without the need for draining, as long as the heater is properly valved and piped.

Based on your application’s specifications, you can use either of these direct tank heating systems to provide consistent and efficient heating for a wide range of mediums. At Sigma Thermal, we offer standard and custom immersion and circulation heaters designed to meet a variety of application requirements.

Thermal Fluid Heating Systems

Thermal fluid heating is a type of indirect heating in which a liquid phase heat transfer medium is heated and circulated to one or more heat energy users within a closed-loop system. Thermal oil, glycol, and water are common heat transfer mediums for these systems. In tank heating applications, finned pipe is installed inside the tank or around the tank to transfer energy from the heat medium to the product in the tank.

Tank Heating and Suction Heating Systems from Sigma Thermal

Sigma Thermal’s tank heating  and suction heating products are built to last and meet CRN, ASME Section VIII Div I, and PED standards. We can provide complete solutions for a wide range of applications including process gas heating, asphalt, liquid vaporizer, high-temperature air, thermal fluid, water, and much more.

To learn more about our products and services, or to get started on your tank heating system solution, contact us or request a quote today.

Regeneration Gas Heating

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Regeneration gas heating technology is important in the oil, gas, chemical, and petrochemical industries.

High process temperatures must be managed as fluid streams, such as natural gas, and are fed into molecular sieve beds or other desiccant style drying systems. As desiccant systems become saturated, regeneration gas heaters dry the sorbent for the next cycle. Regeneration gas heaters are also frequently found in mole sieve applications within air separation facilities, where CO2 and water are removed from the ambient air prior to liquefying and fractionally distilling the air.

Choosing the right heating technology based on a detailed examination of process conditions can help to mitigate the danger associated with high heat sources in the vicinity of combustible substances for hydrocarbon regeneration gas applications. In air separation applications where the process pressures are very low, special attention must be given to tube wall temperatures to avoid tube failure during operation.  Sigma Thermal manufactures high-performance regeneration gas heating systems using a variety of technologies, fuel sources, and burner options.  Options include indirect systems like salt bath and thermal oil systems, as well as direct systems such as fuel-fired convection heaters or electric circulation heaters.

Process Air Heating

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Process air heating is of vital importance to many industrial operations.

In combustion turbine systems, air inlet heating is a key component for optimizing combustion efficiency and maintaining equipment longevity.

For large process facilities, Sigma Thermal offers heating systems that serve as a single user or plant-wide energy source for the distribution of air at individually controlled temperatures to multiple process streams. Typical examples of this type of system are water-glycol systems in SAGD (Steam Assisted Gravity Drain) facilities that are ideal for feeding heated air to once-through steam generators (OSTG), dew point heaters, and other process consumers within the facility.

Heating air and circulating it at tightly controlled temperatures is also essential in the large commercial ovens used by the food processing industry. At Sigma Thermal, engineered thermal oil systems can heat clean air and circulate it through multiple precision-controlled thermal zones with uniform temperature profiles. High temperature air heating at low pressures provides a large measure of safety along with significant efficiency for ongoing operation.

As an industry leading supplier of industrial process heating solutions, Sigma Thermal applies best practice methodologies to engineer systems that can meet virtually any technical and operational specification.

Fuel Gas Conditioning

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Fuel gas conditioning is a critical optimization process for the removal of damaging impurities from gas streams.

Unchecked contaminants such as particulate matter, water, heavy hydrocarbons, condensed gas, hydrogen sulfide, or siloxanes can reduce efficiency, lead to unplanned outages, or cause systems to fall out of compliance.

Many fuel gas conditioning processes require heat energy to function properly, and Sigma Thermal manufactures a number of products specifically for these applications.  Some common examples include dew point (Joule-Thompson) heating, performance heating, and regeneration gas heating.  There are typically a number of heating systems that can be used for these applications, and each one of those system types has its own unique advantages and disadvantages.  Sigma Thermal’s application engineers can help you decide which type of heating system is right for your fuel gas conditioning process and your specific facility.

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