A customized 100% oil-free hot, dry air solution for an efficient pipeline drying project

The project required hot, dry air that was 100% oil-free and could maintain -40 dew point at 176F under cold weather conditions.

The end customer was Enbridge, the largest infrastructure company in North America, and they wanted the job to be done as quickly as possible.

Typically, for this type of application, a competitor would dry the compressed air and then heat it using a diesel-fired burner box of some sort. Some issues with this approach is that a flame is involved in the process and diesel fuel is required to create the flame. The Atlas Copco Rental team configured a customized and energy efficient hot, dry air solution which utilized our PTS 1600 CFM Artic Pack air compressor and 1600 CFM desiccant air dryer along with an additional heat exchanger. Our innovative approach used 100% oil-free compressed hot air that would bypass the aftercooler and use a wafer type heat exchanger eliminating any additional fuel or power requirements all while supplying a full volumetric air flow.

Aecon needed delivery as soon possible, but our local heat exchanger was in the process of having a skid built for it 2,000 miles away. Fortunately, we have a broad network of depot and store locations throughout North America and were able to coordinate a timely delivery to the site.

Weather conditions on site were quite cool, making high heat requirements much more difficult due to radiant heat loss. When testing the equipment, there was a concern that the heat ratio was not ideal. The job required an air temperature close to 176F, but in the initial testing phase, we could only reach 90F. Because the air in Canada is significantly cooler, the team had to come up with a new solution to increase the temperature while maintaining optimal running power.

A series of tests were done to achieve a better heat ratio. A valve was placed to restrict flow and slow down velocity through the heat exchanger which resulted in a significant temperature increase. Adjustments due to weather conditions were needed to keep the heat up while maintaining the air dryer so it would not freeze. We learned that by insulating the heating unit, a higher temperature could be reached. Insulating the hoses and covering them with waterproof material would aid in this along with making sure that rain or snow would not affect the output temperature. We recommended the customer provide hoarding around the dryer and place a 100,000 BTU heater in the air dryer hoarding to prevent valves from freezing as ambient temperatures were below freezing at night.

We anticipated the project to last about two weeks, but with the “Artic Pack 1600,” we were able to reach the required dew point in less than 54 hours saving both time and money for Aecon. This job presented a special opportunity for Atlas Copco Rental to help our customer and exhibit the next big thing for the pipeline industry by using our innovative solution.