Eagle Delivers an Automated Heat Exchanger Assembly Solution

Eagle Precision Technologies Limited, a worldwide leader in tube bending and forming solutions has designed, manufactured and delivered a unique machine for the automated assembly of heat exchangers.

As a result of a customer request, Eagle was challenged to design and manufacture a machine for the assembly heat exchangers in a more cost effective process to offset the higher cost of the technology used to meet new efficiency standards.

The main component of your home heating furnace, both forced air and hot water, is the heat exchanger. This component takes the heat produced by burning fuel and transfers it to the water or air for distribution throughout the house. The HX (Heat Exchanger) tubes must be assembled to the HX panel ensuring an airtight lock so that internal combustible gas does not escape into the ventilation chamber of the furnace. This lock must also be verified to a predetermined “leak rate” that adheres to federal industry standards.

The most common method for fastening the two components is the “ridge lock”. This process involves introducing a set of segmented expand tooling into the tube and expanding a bead around both sides of the panel flange. The result is an interference lock between the HX tube and the HX panel. Eagle has been supplying this proven technology to the industry for over 20 years to many satisfied customers. The problem has always been the slower cycle times required to complete the larger, multiple tube panels. Also, inspection of the completed
assembly required a second operation. To answer the industries call for innovation, Eagle has developed a new line of fully automated heat exchanger assembly machines for the HVAC industry. This new product line offers the latest in automation technology that allows our customers to have the versatility and quality they have come to expect from all Eagle products. With this new platform the HX panel is scanned and loaded into the assembly station. The correct part program is automatically selected and with the touch of button, the sequence is initiated. When the next configuration is scanned the new parameter is automatically set allowing for zero changeover time. After the components are locked in place, the entire assembly is leak tested before being ejected for transport to the final furnace assembly station. This new turn key solution offers customers decreased floor to floor cycle times, fully programmable indexing for multiple part configurations and fully integrated leak test capabilities for assured real time quality assurance of components. Eagle’s HVAC assembly solution includes heat exchanger lines capable of assembling 80% through 90%+ dual stage efficiency furnace components.

Based on customer estimates, this new automated solution is 48% faster than the previous manufacturing process providing significant production savings. 

Eagle worked closely with Festo on the design of the new machine. Festo is a leading global manufacturer of pneumatic and electromechanical systems, components and controls for industrial automation.  When Festo first looked at the 3D concept drawings for the heat exchanger ridge lock and leak testing equipment, they very quickly realized there was a significant amount of valving and digital input requirements (approx. 100 inputs per machine) in a very small footprint. Building a traditional PLC based control system with one localized valve terminal would not be user friendly and make for a potentially complicated control network from the control panel out
to the field devices.

A decision was made early in the design stage to use Festo’s Ethernet IP CPX-CPI decentralized I/O in conjunction with their CPV14 series
of decentralized valves. Using this technology delivered a number of benefits:

• The Intelligent I/O in a compact package was perfect for a congested machine heavy in I/O
• Easy to install and easy to troubleshoot, minimizing downtime
• No need for conduits, junction boxes or hardwired connections
• Localized valving improves efficiency minimizing air consumption and energy.

A Typical Heat Exchanger Assembly

New Eagle 80+ HVAC Assembly Machine