Archive: Mar 2020

Sigma Thermal’s Glycol Heater Used in Potash Mining

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As the potash mining industry continues to grow and change, Sigma Thermal will keep offering innovative solutions with ongoing system design improvements. In this spirit of continuous improvement, we frequently work closely with a global network of industry leaders to develop creative solutions to industry challenges.

Inproheat Industries, one of our Canadian partners, successfully applied their proprietary brand of Submerged Combustion Technology known as SubCom®, along with a Sigma Thermal heater, to a potash mining project.

The Potash Mining Project – Saskatchewan Canada

A 2019-2020 project in Saskatchewan is a shining example that demonstrates the viability of a new and novel solution for potash solution mining projects. In the early stages of project development, Inproheat Industries was approached to quote a submerged combustion system for heating highly corrosive saturated potash brine to temperatures up to 110° C. Already familiar with the high-energy efficiency characteristics of SubCom and its ability to easily contend with scaling solutions, the engineering team believed that this technology would be ideally suited to the job. Inproheat Industries worked closely with the client to develop the engineering specifications and system designs, which included calling on a select group of trusted industry partners to assist with critical components that would best meet the requirements of the project. 

The resulting three-burner SubCom system heats brine to 82° C at 51 MM Btu/h before the brine is driven through a Sigma Thermal HC2 Glycol Heater to further raise brine temperatures to a range of 100° C to 110° C on its way to the injection pumps. The system also includes a Tranter plate and frame heat exchangers to transfer the recovery well brine heat over to the injection brine. The primary objectives of the project were the delivery of a high-efficiency potash mining solution, with a correspondingly low environmental impact, that would provide a significant economic boost to Saskatchewan. Ultimately, Inproheat, Sigma Thermal, Tranter, and other partners assessed the needs of the client and delivered an excellent system solution while providing dedicated support at every stage of the process. 

Innovative Solutions From Sigma Thermal

We form strategic partnerships with key industry players to foster results that exceed expectations and set new standards. We work closely with our customers and industry partners to develop innovative solutions to unique and complex challenges. We would welcome the opportunity to learn more about the dynamic goals of your company. Contact the experts at Sigma Thermal to collaborate on heating solutions for your next project.

HC2 Glycol Heater Advantages

SubCom Advantages

SubCom offers multiple advantages when compared to traditional boiler-heat exchanger methods:

  • SubCom technology lowers expenditures for fuel, maintenance, and operations.
  • The efficiency provided by SubCom drives savings, thus shortening payback periods on capital expenditures.
  • Reduced fuel consumption results in proportionally lower greenhouse gas emissions and, where applicable, lower carbon tax costs.

COVID-19 Impact and Resulting Sigma Thermal Action

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March 17, 2020

Dear valued customers:

First and foremost, we want to thank you for your business. In an unprecedented situation like what we are facing today with COVID-19, we are forced to take a step back from normal business and recognize what is truly important. For Sigma Thermal that is the health, safety, and well-being of our employees, our customers, our vendors, and our other business partners. For that reason, we want to share the actions we are currently taking. We also want to share the potential impacts that this will have on our ongoing operations. Be assured that we are doing everything we possibly can to minimize the impact of this situation on our customers, so long as those actions don’t endanger the health or safety of our employees, customers, vendors, and other business partners.

Our status and the actions we are taking are broadly summarized below.

  • We are strictly adhering to the Centers for Disease Control’s published recommendations for businesses. Those recommendations include guidelines on travel as well as sanitation and social interactions. I will not attempt to communicate those in this letter as they are lengthy and constantly being updated. We are following those updates daily and making adjustments to our policies as needed. You can find details on those recommendations at the following link: https://www.cdc.gov/coronavirus/2019-ncov/community/organizations/businesses-employers.html
  • We have minimized in-office staff – all office employees that can productively work from home have been asked to do so. As the number of cases continues to escalate, we will take additional action, such as further facility restrictions and staggered staffing schedules. As of today, we can confirm that our staff is safe, and no employee has reported a confirmed case of COVID-19.
  • Sigma Manufacturing and all associated manufacturing processes are currently fully operational. Understandably, we have adopted additional distancing and cleanliness measures that could impact productivity. That also could change if and when we receive guidance from health officials that would limit employee’s ability to come to work. Note that this is specific to work being performed by Sigma Manufacturing in our Marietta location. We do use a number of partner fabrication facilities that may be more limited in their current operations than we are.

Below is a summary of the potential impact on your project, parts, or service needs that we see as of today:

  • Supply Chain: We believe this to be one of the least understood and rapidly changing challenges to the global economy. We procure a wide variety of materials and components, and many of our vendors for those items have complex global supply chains. Many vendors can’t and/or won’t say if they are able to meet promised delivery dates. There are also likely to be delays in logistics as air freight, ocean shipments, rail, and truck shipments are all expected to experience delays. What we do know for certain is that there will be delivery impacts, and those impacts will vary greatly depending on the scope and current percentage completion of any given project or parts order. For those customers with active equipment projects, our project teams will be reaching out to you to begin an impact discussion based on your specific project.
  • Customer Visits: We are greatly restricting customer and vendor visits to our facilities. We are instructing our teams to make all meetings virtual until health officials have advised us otherwise. We have also instructed our staff not to travel to visit any customer or vendors until health officials have advised us otherwise. We are making exceptions specifically for customer QA/QC representatives to make final release and FAT witness visits, and for our QA/QC personnel to do the same at our vendor facilities. All other QA/QC oversight can and will be done using virtual meetings and video calls, and/or with photographic verification. Note that any visitors to our facilities will need to request authorization from our staff and submit to some pre-screening questions and verifications.
  • Field Service Needs: We are permitting our service technicians to travel to job sites for any critical service needs of our customers. Note that our Service Team reserves the right to request and review COVID-19 policies and procedures at any field site and decline service if they are not satisfied with those policies. Please also note that we are implementing a virtual service option that will allow the use of video chat and screen share services to support customers remotely when and where travel and direct oversight can be avoided.

If you have any questions for us, please reach out directly to your primary Sigma Thermal contact. We will continue to watch this situation closely and we will continue to communicate with you via your existing contacts. Thank you for your understanding and support during this difficult time. We value you as a customer and we appreciate the confidence you have placed in us by trusting us with your business.


Jeffrey S. Ackel
Chief Executive Officer

Understanding Electric Process Heaters

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Electric process heaters use electricity to increase the temperature of liquids and gases within process systems. Depending on the application, electric process heaters may be used for both direct and indirect heating, which makes them a particularly versatile heating option. To help you find the best electric heater for your needs, we have compiled a concise summary of electric process heater systems and their common uses.

Types of Electric Process Heaters

Electric process heaters are available in two separate styles: immersion heaters and circulation heaters. Each type offers distinct advantages for particular applications.

Immersion Heaters

Rendering of a Sigma Thermal branded electric immersion heaterImmersion heaters heat gases and liquids through direct contact. As the name suggests, the tubular electric elements are immersed in the process fluid. The major benefit of this type of process heater is that nearly all of the electricity generated is converted directly into heat with almost 100% efficiency. Heating elements are typically composed of highly corrosion-resistant and heat-resistant materials, such as Alloy 800, to ensure the optimal operation and service life of the heater.

Circulation Heaters

rendering of a sigma thermal branded electric circulation heaterA circulation heater heats fluid as it passes through an enclosed system directly over the heating elements. The heater is often in the tube or pipe through which the gas or liquid material flows. Circulation heaters are highly specialized, and must often be tailored to the needs of each individual application.

Electric Thermal Fluid 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. An electric circulation heater can be used as a heat source for these closed-loop thermal fluid systems.

Common Applications

Heat control is critical to a wide variety of processes, from melting materials into formable resins to superheating gases and initiating chemical reactions. Below is a short summary of common applications in which electric process heaters are used.

Jacketed Reactor Heating & Cooling

jacketed reactor heating codingJacketed reactors are often kept at processing temperatures up to 800° F, and must be maintained at a stable temperature to ensure proper functionality. As the name implies, the reactor is covered with a secondary protective jacket around the surface of reactor vessel. Steam or thermal fluid is circulated through the jacket to control the reactor’s temperature.

Molding & Extrusion

Molding and extrusion processes require very specific temperature control. In addition to maintaining the temperature of the resin to ensure ideal part formation, the temperature of the part-forming extruder or mold must also be regulated. Closed-loop thermal fluid systems are used to monitor and adjust the system temperature as needed. Although steam heating systems are also used for molding and extrusion applications, they are not as safe as thermal fluid systems due to the high pressure required for effective steam heating. 

Molten Salts

Sigma Thermal Molten Salts SystemMolten salts, or salt melts, refer to a range of materials composed of fluoride, chloride, or nitrate which are used for thermal energy storage and high-temperature industrial processes. Molten salts are valued for their ability to retain liquid form in temperatures upwards of 1000° F without increasing vapor pressure. They are often used in high-energy batteries for solar arrays and high-temperature metal treatments.

Other Applications

In addition to the above, other common applications of electric process heaters include:

  • Asphalt production
  • Glycol and amine re-boiling
  • Freeze protection
  • Tank temperature regulation
  • Liquid vaporization
  • Condensate stabilization
  • Viscosity reduction
  • High temperature air control
  • Nitrogen and thermal fluid heating
  • Heating of process gas, fuel gas, and natural gas

Electric Process Heater Considerations

When selecting the best electric process heater for your application, it is important to consider the needs and limitations of your equipment. Be sure to consider the following key factors:

  • Fluid flow rate. Consider the volume or the flow rate of fluid to be heated to determine the heater’s required capacity.
  • Process temperature. The greater the temperature increase, the greater the power output required.
  • Thermal properties. The fluid’s thermal and physical properties help to determine the appropriate watt density.
  • Footprint. Space and other physical limitations must be considered when determining the heater’s size and placement.

Sigma Thermal Solutions

Sigma Thermal Solutions offers the highest quality thermal immersion and circulation electric heaters on the market. We offer a watt-density range from 2–60 watts per square inch, and each system is specifically engineered for versatility to meet a wide range of system requirements. To ensure superior quality, our electric process heaters can be manufactured to meet and exceed a variety of industry standards, including ASME Section VIII Div I, CRN, and PED.

For more information on our superior thermal solutions, contact the experts at Sigma Thermal today or request a quote.

Fuel Gas Conditioning for Combustion Turbines

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Sigma Thermal Fuel Gas Conditioning Outside
The performance and longevity of an industrial or aeroderivative turbine rely heavily on the quality of the liquid or gaseous fuel employed. Inferior fuel can affect the turbine’s reliability, structural integrity, and ability to comply with local, state, and federal emission standards. With these considerations in mind, ensuring fuel gas is properly treated to remove impurities is vital for any turbine or combustion turbine operation.

What Is Fuel Gas Conditioning?

Fuel gas conditioning is the method by which fuel is filtered to remove impurities and readied for use in combustion systems. Both liquid and gaseous fuels must be conditioned to ensure that all contaminants are removed. Unchecked, impurities in fuel can compromise the system, resulting in damage, failure, or inadequate performance. 

Solid, liquid, and gaseous contaminants can be found in fuel gas, and all have a tangible effect on the performance of the combustion system. These are introduced into the natural gas supply during mining, transportation, and production, and include:

  • Calcium carbonate
  • Construction debris
  • Gas hydrates and ice
  • Glycols from dehydration processes
  • Iron sulfate, iron, and copper sulfide
  • Lubricating oil, wet scrubber oil, crude oil, and hydrocarbon liquids
  • Rust
  • Sand and clay
  • Water and saltwater

With appropriate treatment, these contaminants can be removed from the fuel prior to injection into a combustion system. The initial fuel gas conditioning process removes solid and liquid impurities through the use of an efficient coalescing filter. Once the solids and liquids have been removed, the fuel gas is superheated using fired or electric heating equipment. Superheating, or dew point heating, increases the gas to a temperature above the hydrocarbon dew point to prevent liquid hydrocarbons from forming in the fuel. 

When Is Fuel Gas Conditioning Used?

In addition to being used for the removal of contaminants, fuel gas conditioning can be used to ensure the fuel has the appropriate chemical makeup and consistency for use in gas turbines, for both operational and warranty purposes.

Chemical Composition

Depending on the system, manufacturers may specify a Methane number or Lower Heating Value requirement for fuel used in their equipment, and the fuel must be treated accordingly. In some cases, a fuel gas source may be too rich, and heavy hydrocarbons must be removed to make the fuel compatible with the combustion system. 

Moisture & Hydrocarbon Liquids

The reduction of pressure when fuel gas is transported from primary pipelines to the combustion turbine can reduce the temperature of the fuel below its hydrocarbon dew point. This temperature drop allows both moisture and hydrocarbon liquids to collect and contaminate the fuel, necessitating the treatment of the fuel prior to its injection into the system to ensure optimal operation.

Dangers of Improper Fuel Gas Conditioning

If fuel gas remains unconditioned or improperly conditioned before being introduced into a combustion unit, the operator risks:

  • System blockage
  • System or part damage, such as oxidation, corrosion, or thermal erosion
  • Increased emissions
  • Combustor flameout
  • Deterioration of thermal barrier coatings
  • Loss of seal segments

If left unchecked, contaminated fuel ultimately results in reduced efficiency, unplanned outages, and non-compliance with safety regulations. Additionally, once low-quality fuel has been introduced into a gas turbine, it is difficult to determine the specific issues that result, as the effects will cascade throughout the system. 

Signs You Have Fuel Gas Quality Issues

If you are experiencing the following in your gas turbine(s), you may have gas quality issues:

  • High exhaust temperature spread (T5 spread)
  • Combustion instability
  • Acoustic issues
  • Combustor flameouts
  • Increases in emission outputs
  • Abnormal power outputs
  • Visible signs of oxidation, erosion, and abnormal wear in hot end components
  • Deposits of yellow sulfur on control elements
  • Loss of control of valves
  • Freezing or seizing of pressure regulators

Fuel Gas Conditioning from Sigma Thermal

Fuel gas conditioning is critical to the performance and longevity of turbine combustion systems. Ensuring fuel is properly conditioned necessitates the use of quality heating equipment. For assistance finding a fuel gas conditioning solution that meets your needs, contact the experts at Sigma Thermal.


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