Case Study: Delta Ducon PERMA/flo Type XT Rotary Valves Solve Fly Ash Handling Challenges at Mid-West Pulp & Paper Mill

The Challenge:

In early 2024, a prominent Mid-Western USA Pulp & Paper Mill faced persistent operational challenges with its existing double dump valves. These valves were critical components in the mill's fly ash handling system, specifically at the discharge of an electrostatic precipitator (ESP), feeding a dry drag chain conveyor. The material being handled was a highly abrasive wood-based fly ash, flowing at an approximate rate of 5.5 tons per hour.

The mill reported that the double dump valves were a constant source of frustration. Their design and operation led to significant wear, resulting in frequent, difficult, and costly maintenance interventions. This ongoing issue disrupted operations and incurred substantial expenses, prompting the mill to seek a more reliable and efficient solution.

(Briefly, an Electrostatic Precipitator (ESP) in a power boiler at a pulp and paper mill is an air pollution control device. Its primary function is to remove fine particulate matter, such as fly ash, from the exhaust gases (flue gas) before they are released into the atmosphere. It works by electrically charging the ash particles, which are then attracted to and collected on charged plates, thus cleaning the gas stream.)

The Solution:

Delta Ducon was contacted to address this critical problem. After assessing the mill's specific needs and the demanding nature of the wood-based fly ash, Delta Ducon recommended their robust 12" PERMA/flo Type XT Extreme Rotary Valves. These valves are engineered for severe abrasive applications, making them an ideal candidate for the mill's challenging environment.

In the first quarter of 2024, the Michigan mill proceeded with the replacement of the initial two problematic double dump valves with the recommended 12" Delta Ducon PERMA/flo Type XT Extreme Rotary Valves.

Overview of the PERMA/flo Type XT Extreme Rotary Valve:

The Delta Ducon PERMA/flo "XT" Extreme Rotary Valve is engineered for demanding applications, prioritizing long life, rugged durability, and ease of maintenance. A key feature is its field-adjustable and replaceable rotor, which works in conjunction with a separate wear shoe. Both the rotor and the wear shoe are cast from P-33 Abrasion Resistant alloy, ensuring exceptional resistance to wear with a minimum hardness of 550 BHN. This innovative design allows factory settings to be readjusted multiple times in the field before the need for replacement, significantly extending the valve's operational lifespan and reducing maintenance frequency. Furthermore, standard "XT" valves are capable of handling temperatures up to 500°F, with specialized high-temperature models designed to manage 800°F continuous operation and withstand spikes up to 1000°F. The valve also incorporates outboard-mounted bearings, protecting them from the abrasive material flow and contributing to consistent performance. These advanced features collectively minimize downtime and reduce the total cost of ownership in severe abrasive environments.

Delta Ducon's Expertise in the Pulp & Paper Industry:

Delta Ducon is a recognized leader in providing specialized equipment and comprehensive systems for material handling applications within the Pulp & Paper and Forestry industries. Their extensive capabilities include designing and implementing dilute and dense phase vacuum and pressure pneumatic conveying systems, railcar and truck loading/unloading solutions, and advanced ash and dust removal, storage, and transport systems. They also offer injection technologies and a range of rotary valves for multiclone, ESP, and fabric filter outlets, including their high-performance PERMA/flo Extreme Duty rotary feeders/airlocks, and abrasion-resistant PERMA/flo pipe and fittings. Furthermore, Delta Ducon provides essential components such as blower packages, isolation valves, and aeration systems, demonstrating their holistic approach to addressing the unique material handling challenges faced by the pulp and paper sector.

The Results:

A year after the initial installation, the success of the Delta Ducon PERMA/flo Type XT valves has been unequivocally demonstrated. The mill has experienced a significant reduction in maintenance requirements and associated costs, confirming the superior wear resistance and reliability of the XT valves compared to their previous solution.

Based on this positive experience and the proven performance of the first two units, the customer is now actively planning to replace the next two double dump valves with two more 12" Delta Ducon PERMA/flo Type XT Extreme Rotary Valves for installation in 2025. This upcoming installation represents the next step in a broader long-term strategy to systematically replace all eight of the original double dump valves with Delta Ducon's high-performance rotary valves.

This ongoing partnership highlights Delta Ducon's commitment to providing durable and effective solutions that directly address the operational challenges faced by industries like pulp and paper, leading to improved efficiency and reduced total cost of ownership for their clients.

For more information click: https://www.deltaducon.com/industries/pulp-and-paper-and-forestry