Advancing Precision Heating & DryingAdvancing Precision Heating & Drying

In industrial processes, achieving uniform moisture content in bulk powders is critical to ensuring consistent product quality and operational efficiency. Yet traditional drying methods often fall short, plagued by inefficiencies and high energy consumption. For industries seeking to scale production while meeting modern sustainability goals, innovative solutions are a must.

Crescend Technologies, a leader in solid-state microwave systems, partnered with HAF Equipment to address a complex drying challenge for a mixed bulk compound. This collaboration brought together Crescend’s expertise in microwave energy and HAF’s cutting-edge pneumatic mixer design, delivering a new approach to bulk powder drying. The result was high precision, efficiency, and scalability.

The Challenge: Solving the Bulk Powder Drying Dilemma

Heating and drying bulk powders poses a unique set of challenges. For this project, the customer faced several operational pain points with a conventional conduction-based heated jacket mixer.

* Inconsistent Heating: Traditional systems often produce unevenly heated material, leading to product quality issues such as clumping or poor flowability. In this case, the material was overheating along the walls becoming very sticky and clumping to the vessel creating a product quality issue as well as cleaning challenges between batches.

* Energy Inefficiency: Conduction-based heating vessels consume significant amounts of energy, increasing operating costs without delivering uniform results. Conducting the heat from the jacket is slow as the material has insulating properties.

* Downtime and Maintenance: The material itself is very abrasive where traditional mixers were not suitable as the material would wear out the parts of the mechanical mixer. Additionally, the mechanical nature of grinding during mixing was degrading the product quality. The need for frequent maintenance of existing equipment results in costly downtime, further disrupting production schedules.

* Scalability Challenges: As demand grows, scaling traditional heating and drying methods can require significant capital investment and infrastructure upgrades. A solution was needed to improve the processing time as the existing process was very slow, had high maintenance costs, and ultimately would not be able to scale as demand increased.

This customer was mixing several powdered materials as part of its recipe. The requirement was to heat the material to 120°C and let big batches of 2,000-3,000 lb of powder mixture cure in large, heated drums.    

The problem is this is not very efficient. The drums were serving as large convection ovens where the material was heated from the outside of the vessel. The client was wasting a lot of energy to heat the vessel and wasting time and energy waiting for all the material to get up to temperature. They needed to find a faster, more effective, and more efficient way to process the material at scale.

Crescend’s task was to design a microwave drying system capable of overcoming these obstacles, offering precision heating tailored to the unique properties of the mixed bulk compound. By combining advanced simulations, dynamic frequency tuning, and rigorous testing, the project sought to deliver a solution that could meet the customer’s immediate needs and scale with their growing operations.

The Solution: Combining Expertise in Equipment, Engineering, & Innovation

Crescend Technologies led the charge in engineering and testing to create an optimized solid-state microwave drying system with HAF’s vertical cone-shaped pneumatic mixer being the ideal vessel. This vessel is ideal for adding microwave energy due to its inherent design characteristics. This collaboration involved a multi-step approach, supported by cutting-edge simulation software, rigorous lab testing, and engineering expertise.

HAF’s pneumatic mixer (HAF Equipment)

The Design Process Step 1: Material Analysis & Simulation

Understanding the electromagnetic and thermal properties of the bulk material was the cornerstone of this project. Crescend employed dielectric analysis and COMSOL Multiphysics simulations to create physics models and microwave heating simulations for this project.

These simulations are important for validating design concepts, investigating the consequences of changes in existing system parameters, and predicting and optimizing system performance as it eliminates the need for building costly, time-consuming prototypes and reduces the development time.

In this case study, the simulation revealed the ideal frequency range and heating pattern required for consistent heating as demonstrated in image A. This data formed the blueprint for customizing the microwave system’s power and frequency settings.

COMSOL simulations showing electromagnetic field distribution and thermal mapping (Crescend Technologies)

Step 2: Engineering Precision with Crescend’s Patented Technologies

Crescend’s solid-state microwave generator, supported by its patented PrecisePower software, was the backbone of this solution. PrecisePower enabled:

* Dynamic Frequency Tuning: Adjusting the microwave frequency in real-time to ensure optimal energy absorption

* Real-Time Power Modulation: Adapting power output based on changing material properties during the drying process

* Advanced Diagnostics: Monitoring reflected power to minimize energy waste and prevent equipment inefficiencies

Results showed more than 90% of applied power is absorbed by the powder material. This level of precision not only improved energy efficiency but also protected the system from potential damage from reflected power.

Step 3: Collaborative Testing and Validation

Crescend conducted rigorous lab testing to fine-tune the system. Key milestones included:

* Pilot-scale material processing to validate system parameters

* Real-time monitoring of microwave power and material temperature

* Data-driven optimization to enhance process reliability and scalability

The Results: Setting New Standards for Bulk Powder Heating & Drying

The collaboration between Crescend and HAF delivered groundbreaking results:

* Uniform Heating and Drying: Achieved consistent temperature and moisture content across batches, ensuring product quality and reliability. The results demonstrated consistent heating and moisture reduction, with variances of less than ±2% across batches, significantly surpassing the performance of traditional drying systems.

* Energy Efficiency Gains: This approach is radically different from traditional approaches where the material is traditionally indirectly heated. Whereas with solid-state microwave the material is directly heated. This approach to energy efficiency increases from 50% to 90% of electric power, making the process more sustainable.

* Enhanced Scalability: Validated system performance for large-scale production

The integration of Crescend’s solid-state microwave technology with HAF’s mixer demonstrated the power of combining innovative hardware with advanced software and solid-state microwave technology for industrial applications.

Crescend Technologies PTL-50 kW (Crescend Technologies)

The Future of Industrial Drying is Here

As companies face increasing pressure to improve results like product quality and sustainability while being driven by the demand for increased production, Crescend Technologies delivers new high power, microwave technology solutions.

Crescend’s solid-state microwave systems, enhanced by advanced control features, are enabling innovative microwave applications once thought unattainable. By collaborating with equipment providers like HAF Equipment, the combined solution empowers businesses to overcome traditional powder heating and drying system limitations.

Crescend Technologies offers solid-state microwave technology with power levels from 2.5 to 400 kW and beyond.

Lori Tybon has more than two decades of experience in marketing and business development, specializing in technology and innovation. She currently leads marketing efforts at Crescend Technologies (Glendale Heights, IL), focusing on advancing solid state microwave energy for applications in heating, drying, and advanced industrial processes. For more information, call 847-908-5400 or visit crescendrf.com.

Contributions: Ken Kaplan, Crescend, conducted the study, collected data, and oversaw the engineering design work. Jonathan Tweedt, Crescend, performed the simulations and presented the original findings from the study. Adam Jones, Crescend, contributed to data interpretation and edited the article. Mitch Lund, HAF Equipment, contributed to the original study and reviewed the article.