Capturing heat from the furnace


Regenerators: Another Approach

Another potential tool for salvaging a significant amount of the heat energy from a furnace exhaust is the regenerator. Although less commonly used than recuperators, regenerators are still widely used in high temperature furnaces such as glass and steel reheat furnaces. A regenerator uses two or more vessels or vessel sections containing a high thermal conductivity matrix. The matrices may be ceramic or metallic.  Exhaust passes through the matrix giving up a large portion of its heat before discharging.

After the matrix is heated, the stream is mechanically directed to another section or vessel and incoming combustion air is drawn through the hot section and heated. The regenerator alternates the hot and cold flows so heat recovery is continuous. The advantage of a regenerator over a recuperator is that it presents a much larger amount of heat exchange surface to the hot exhaust flow.

A disadvantage is that the heat content of the incoming air has some variation, making precise combustion control more difficult. This can be reduced by faster cycle times or the use of multiple vessels at various stages of cooling. Another consideration is that some exhaust products inevitably remain in the vessel to combine with incoming combustion air. 

In the Future

Self-recuperative burners can be retrofit on existing furnaces. Adjustments in combustion air and fuel flows and furnace temperature will be necessary. Courtesy: Eclipse Combustion Inc.There are still a good many plants with major energy reduction potential, and the level of adoption is uneven. Russ Chapman from Firebridge notes that larger companies are starting to benchmark their large plants against each other, and against the competition, in terms of sustainability of the plants. However he feels that a single-minded focus on short term profitability sometimes means a lack of incentives for long-term energy saving projects.

As an example he cites a Tier 2 automotive manufacturer that has a plant with a monthly energy bill of $200,000 per month. He feels this company could reduce that bill by 25%. However the plant is on its third plant manager in three years, and no action is taking place in making improvements. Clearly, energy savings are not always enough. 

Global Competition Driven

Chapman notes that smelting in the copper mining industry is an example of an industry starting to move in this direction. “It’s because they are competing worldwide and are comparing key performance indicators, making efforts to get in line.”

Asked if effective heat recovery can lower greenhouse gas emissions from industrial furnace applications, Chapman replies, “Absolutely! Energy reduction equals emission reduction. The only inhibitor is scale.” He explains, “The cost of retrofitting little furnaces is disproportionately higher than one operating at, say, 45 MMBtu/hr or larger, so the economic case is more difficult to make.” 

Taking the Step

Unquestionably, heat recovery strategies have huge potential for reducing energy bills and plant emissions.

Jim Roberts from Eclipse notes, “Sometimes the cost looks staggering, but remember that most furnaces have a very active running schedule, so the paybacks, even at low gas costs, can be very fast. Even if paybacks are in the two-to-three year range, the long-term savings are worth it.” 

More Info:

Bloom Engineering

DOE Industrial Technologies Program

Eclipse, Inc.

Energy Solutions Center Info on Furnace Heat Recovery

Firebridge Inc.

Hauck Manufacturing

<< First < Previous 1 2 Next > Last >>

No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2015 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
Your leaks start here: Take a disciplined approach with your hydraulic system; U.S. presence at Hannover Messe a rousing success
Hannover Messe 2016: Taking hold of the future - Partner Country status spotlights U.S. manufacturing; Honoring manufacturing excellence: The 2015 Product of the Year Winners
Inside IIoT: How technology, strategy can improve your operation; Dry media or web scrubber?; Six steps to design a PM program
Getting to the bottom of subsea repairs: Older pipelines need more attention, and operators need a repair strategy; OTC preview; Offshore production difficult - and crucial
Digital oilfields: Integrated HMI/SCADA systems enable smarter data acquisition; Real-world impact of simulation; Electric actuator technology prospers in production fields
Special report: U.S. natural gas; LNG transport technologies evolve to meet market demand; Understanding new methane regulations; Predictive maintenance for gas pipeline compressors
Warehouse winter comfort: The HTHV solution; Cooling with natural gas; Plastics industry booming
Managing automation upgrades, retrofits; Making technical, business sense; Ensuring network cyber security
Designing generator systems; Using online commissioning tools; Selective coordination best practices

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
This article collection contains several articles on the vital role that compressed air plays in manufacturing plants.
This article collection contains several articles on the Industrial Internet of Things (IIoT) and how it is transforming manufacturing.
This article collection contains several articles on strategic maintenance and understanding all the parts of your plant.
click me