Industrial Waste Heat Recovery Systems

What Are Waste Heat Recovery Units?

Waste Heat Recovery Units (WHRUs) work by recovering the thermal energy from the hot exhaust and gases discharged by industrial equipment such as incinerators and turbines. This energy is then repurposed to heat other media and materials, including asphalt and oil. WHRUs are available in various designs and styles.

By capturing heat that would otherwise go to waste, WHRUs allow facilities to use that energy for other applications, making them a valuable addition to various industries. They can greatly improve the overall efficiency of industrial plants.

Why Use Industrial Waste Heat Recovery Systems?

Using heat exchanger systems for industrial waste heat recovery is a simple method to enhance facility efficiency. With vast expertise in this field, Sigma Thermal collaborates with clients from diverse industries to develop innovative, profitable waste heat recovery solutions.

In addition to repurposing high-temperature waste streams, our solutions can recover and reuse low-temperature heat using heat pumps. This technology is used in heat recovery from wastewater, seawater, and data centers, where surplus heat is utilized for district heating.

The Waste Heat Recovery Cycle Explained

A waste heat recovery cycle is a sustainable and cost-effective way to reuse thermal energy from the exhaust gas of industrial plants. It utilizes an intermediate fluid, such as oil or pressurized steam or water, to transfer heat from the exhaust gas to the organic fluid in the ORC (Organic Rankine Cycle) evaporator. The organic fluid vaporizes, expanding and generating high-pressure steam that drives the turbine. The turbine, in turn, powers the generator, producing electricity that can be utilized in the plant.

After completing its work in the turbine, the vaporized organic fluid goes through the cycle again. It moves to the condenser, where it’s cooled and turned back into a liquid before passing through the pump and beginning the cycle once more. This process enables plants to reuse the waste heat that would otherwise be lost and convert it into useful energy, reducing overall energy consumption and greenhouse gas emissions.

  • Complete Closed Loop System
    Complete Closed Loop System
    Click on the dots to learn how Sigma can optimize your heating systems and the benefits of using our closed loop system.
    Material Hadling Wearhouse


    Once a viable source of waste heat has been identified, a consumer of the available waste heat must also be identified. Typical consumers include:



    Any exhaust gas stream with temperatures above 450°F has the potential for significant waste heat recovery. Typical Producers include:



    Waste Heat Recovery Units (WHRUs) recover thermal energy from the hot exhaust and gases discharged by industrial equipment (i.e. incinerators, turbines). The energy is then repurposed to heat other media and materials.

  • Combustion Air Pre-Heat System (CAPH)
    Combustion Air Pre-Heat System (CAPH)
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    Material Hadling Wearhouse
    Pin Pin Pin Pin

    Thermal Fluid Heater

    A heater utilized to warm the fluid of choice before continuously recirculating it through the system, transferring indirect heat to the appropriate process systems, machinery, and materials. Produces exhaust gases.


    Combustion Air Ductwork

    Fresh air from the heat exchanger to the burner


    Preheater / Heat Exchanger

    Transfers energy from the exhaust gas to the combustion air


    Combustion Air Fan

    Circulates combustion air and outside air

Benefits of an Industrial Waste Heat Recovery System

Industrial Waste Heat Recovery System

Here are some advantages of industrial waste heat recovery systems:

  • Save on everyday fuel consumption: Capturing and reusing waste heat lets companies significantly reduce consumption of new energy sources such as electricity and natural gas. This reduction in energy consumption not only translates into cost savings but also contributes to a more sustainable future.
  • Repurposing harmful emissions: Certain waste gases generated in industrial processes are toxic and can’t be released directly into the environment without proper treatment, such as incineration. Rather than simply disposing of incinerated waste, companies can use waste heat recovery systems to repurpose the waste in a way that boosts their facility’s productivity.
  • Sell carbon credits back to industry: Carbon credits can be sold to other companies or entities seeking to offset their own carbon emissions. By incentivizing carbon reduction in this way, waste heat recovery systems can contribute to a more sustainable future while also providing a potential revenue stream for companies.
  • Eligible for state and/or federal funding: Waste heat recovery systems are a strong candidate for state and federal funding programs, as they contribute to reducing carbon emissions. These programs often offer grants, tax credits, loans, or rebates for businesses that invest in energy-saving technologies.

Industrial Waste Heat Recovery Systems From Sigma Thermal

Industrial Waste Heat Recovery Systems From Sigma Thermal
Waste Heat Recovery Systems

Incorporating an industrial waste heat recovery system into your facility’s operations can offer numerous benefits to your business. Contact us or request a quote today to learn more about how this technology can boost your company’s efficiency.

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