Single Pass Vs. Triple Pass Rotary Dryer

Single Pass Vs. Triple Pass Rotary Dryer – Understanding the Differences

Rotary dryers are a versatile option for reducing moisture in a product. They are used with a variety of materials across a wide range of industries. Some of the novel ways our customers use rotary dryers to help repurpose materials that used to go to waste, include:

  • Turning poultry bedding into fertilizer
  • Turning municipal sludge into fertilizer
  • Drying and sterilizing dairy bedding for reuse
  • Drying hemp to prolong storage life

Uzelac Industries produces two types of rotary drums for our rotary drying systems—single pass and triple pass. In this blog post, we will explain the differences between the two to help you decide which type will work better for your drying requirements.

Single Pass Drum for Rotary Dryer

Single pass drums consist of one cylinder internally flighted. The drum rotates at a constant speed and product moves in one direction along the drum from inlet end to outlet end while being showered through an air steam with a large cross-sectional area. This drum mechanism is better at handling larger volumes of product without choking out the airflow. If you need to dry dense material, the single pass rotary dyer is the right choice.

Single pass drums have greater flexibility in flight design, helping us optimize shower pattern to spread material more evenly across the air stream. Another option we have in flight configuration for single pass drums is adding spiral flights in different patterns throughout the drum. These flights act like a screw conveyor and, depending on the orientation, can be used to either increase or decrease retention time.

Triple Pass Drum for Rotary Dryer

Triple pass drums consist of three concentric flighted cylinders nested inside of each other. The drum rotates at a constant speed and product moves in a serpentine path through the three cylinders. Product enters the inside of the inner cylinder and travels from inlet end to outlet end. When it gets close to the outlet end, the product hits the headplate at the end of the intermediate cylinder and changes direction, passing between the inner cylinder and intermediate cylinder and travels back toward the inlet end. Once it gets to the inlet end, product hits the headplate at the end of the outer cylinder, changes direction, and travels back toward the outlet end, between the intermediate cylinder and outer cylinder.

Triple pass drums are ideal for handling light materials and products that are sensitive to higher temperatures. This dryer mechanism can run at a lower temperature and has a higher air velocity due to the reduced cross-sectional area between the cylinders. Triple pass drums are more expensive up front but are more efficient and tend to have a lower cost of operation. This is because these drums run at a lower temperature, leading to less fuel consumption, and typically have a smaller drum drive since product is evenly dispersed between the three cylinders.

Another benefit to triple pass drums is that they have a smaller footprint, usually around 20% shorter than the equivalent sized single pass drum. If space is very limited, we also offer a shorter, larger diameter version of most single and triple pass drums, called a big belly drum. Big belly drums allow for an increase in drum volume without an increase in length.

When you need a reliable drying solution, our rotary dryers get the job done. We serve customers in many industries. Talk to us about your requirements and we can guide you to choose between single pass and triple pass rotary dryers. Contact us online or send us an email.

Items Dried

Items Dried

Here are some of the products we have experience drying. if you do not see your desired product in this list, we have a Test Dryer in-house that we can use to test the viability of your product with our technology!

  • Municipal and Industrial Wastewater Sludge
  • Bone Meal
  • Blood Meal
  • Feather Meal
  • Fish Meal
  • Poultry Manure
  • Dairy Manure Bedding
  • Egg Shells
  • Hemp
  • Sand
  • DAF
  • Diatomaceous Earth
  • Digestate
  • Minerals
  • Potash
  • Ammonium Sulfate
  • Wood Fiber/Waste (Biomass)
  • Agricultural Waste
  • Brushite
  • Food Waste
  • Compost
  • Alfalfa
  • Brewers Grain
  • Distillers Grain
  • Citrus Pulp
  • Pineapple Bran
  • Potato Waste

Chicken Litter and Anaerobic Digestion Explained

Chicken Litter and Anaerobic Digestion Explained

There are various types of organic products that can be used as a fertilizer, and one of those products is poultry litter. Poultry litter typically is broiler manure mixed with bedding (wood shavings or another type of biomass) as opposed to egg layer manure, which is typically collected without the use of bedding. The quality of a poultry litter varies with the type of poultry, litter, diet, and the collection and storage methods.

Rotary dryers help poultry agri-businesses process chicken litter and manure for use as other products. Both rotary and sludge dryers process waste products for reuse directly in the business or as saleable products.

Learn how poultry waste can make your business money instead of adding to your overhead with storage and landfilling costs.

How is Poultry Litter and Manure Used?

Chicken Litter Contains Valuable Nutrients

Poultry litter has been considered a great fertilizer for years as it contains numerous nutrients that plants require to grow, including:

  • Nitrogen (N)
  • Phosphorous (P)
  • Potassium (K)

It also contains trace nutrients like copper (Cu), zinc (Zn) and arsenic (As).

Poultry Manure and Litter Make Effective Soil Amendments

Chicken litter is also used for natural soil amendment as it can improve soil that was previously damaged by chemical fertilizers. Continuous crop cultivation and the use of chemical fertilizers negatively impacts overall soil quality. Adding poultry litter and manure has proven beneficial to increasing soil vitality, as follows:

  • Decreases soil density
  • Improves water retention
  • Increases organic matter content
  • Improves oxygen diffusion

Using Poultry Litter and Manure as Cattle and Fish Feed

Poultry manure or litter can be used as feed for cattle and fish. However, it is important to ensure you remove foreign materials such as feathers, plastic, ash, and debris first. The danger of contamination in unprocessed poultry litter is high because it contains pathogens such as:

  • Clostridium
  • Enterobacter spp.
  • Salmonella
  • Feed additives (arsenicals, coccidiostats, antibiotics)

Properly processed poultry waste mixed with minerals and protein makes a safe and economical filler for cattle feed. In fact, it’s been a feed ingredient for four decades.

How Poultry Litter is Converted to Biogas?

What has become more popular as of late with the initiative to “go green” is the use of poultry litter for biogas through anerobic digestion. The digesters extract methane and carbon dioxide, called biogas, which can be used for fuel, electricity, and heat.

Once digesters have done their job, you are left with solids that are referred to as digestate. This is what can be dried to create the organic fertilizer that is referenced above. The benefit to this is that there is zero waste. The digestate would not have to be landfilled, and it is turned into a saleable organic product.

Uzelac Industries has years of experience with digestate drying. Learn more about digestate drying and the benefits. Contact us online or feel free to give us a call 414-529-0240 to discuss your digestate drying needs.


Uzelac Rotary Drying Systems to Process Layer Manure



Application of Uzelac Manure Drying Systems

Uzelac Industries based in Greendale, WI. has developed considerable expertise in the design and installation of rotary drum dryers capable of reducing the moisture content of manure from high-rise houses with 65 percent water or belt systems with 45 percent water down to 15 percent. Manure handling and drying installations convert a waste product into a valuable pathogen-free fertilizer in a commercially acceptable form for domestic and institutional applications.

Direct application of raw manure to farmland will be subject to increasing restriction as nitrogen percolating through soil contaminates ground water and hence wells. Runoff entering streams and waterways will come under heightened scrutiny from state and federal regulators.

A Uzelac rotary dryer installations reduces odor, obviating complaints and lawsuits and when used with belt manure collection, effectively eliminates fly problems without expenditure on insecticides. In the future environmental regulations may necessitate on-farm or remote processing of manure before application.

Read the rest of this article Written by Dr. Simon M. Shane on


New Gaskets



(Picture of our New Gasket)

Improved dryer drum outlet tube gaskets wear 50% longer

We all know dryer tube gaskets are a consumable part of your dryer that can be expensive to replace.

At Uzelac Industries, we have created a modified dryer outlet tube gasket that is more cost effective than the prior styles over the life of your dryer.

Are you looking for a way to improve the efficiency of your dryer while saving money?

The old gasket had riveted seals that fall off when they wear down to the rivets.

Our new gaskets have a bolted-on seal—where the bolts ride above the area of wear, which allows for about 50% more wear time on the seals.

Rather than purchasing a completely new gasket when the seals eventually wear out, our seals can be purchased separately and bolted onto the existing gasket—saving you hundreds of dollars every time this basic maintenance is needed.

Reach out to a Uzelac representative today to take advantage of this amazing cost-saving technology.

Uzelac Industries Engineers Earn Professional Certifications in SOLIDWORKS



(Example of a model created in SOLIDWORKS)

Uzelac Industries Engineers Earn Professional Certifications in SOLIDWORKS

Uzelac Industries is proud to announce that our engineers Jordan Fults, Josh Kudick and Pratik Kumar have received their Professional Certifications in SOLIDWORKS. Only 399 people in the state have this professional certification. Uzelac Industries uses SOLIDWORKS for 3-D Modeling and design, which is a very efficient program and can help see potential issues before anything is fabricated.

Uzelac Industries is committed to our employees’ continuous improvement and growth through training, courses, and testing. We believe it is important to adapt to new technologies and programs that will better our business and our people.




Uzelac Industries |Nov. 3rd, 2020


Make sure to get on our maintenance schedule to minimize any possible downtime!

We have the experience and equipment to resurface M-E-C drum track / tires, safely and efficiently, minimizing downtime.

Resurfacing track / tires creates a flat level surface:
• Eliminates pitting and prevents cracking
• Eliminates vibration by reducing ripples in
track / tires

Resulting in:
• Prolonged life of bearings, trunnions, thrust
rollers and the track / tires itself
• Improved dryer tracking performance
Reduced trunnion adjustment

Uzelac Industries has the ability to replace track / tires located in the end of your dryer drum using well-established and proven methods.

We offer an alternative technology to replace in-board tracks that will reduce down time
during replacement by over 50%. We completely eliminate the need to cut-off the end of the drum to replace the track / tires.

We replaced the in-board track on a 12’ x 72’ M-E-C drum for a customer in Dallas. This drum has been running for over 3 years without any issue. Our technology saved the facility over 130 hours of downtime, compared to the traditional process.

Rotary Drying is Fast and Effective


Rotary Drying is Fast and Effective

Uzelac Industries | Aug 07, 2020

Rotary Drying is a fast and effective method of drying that requires a relatively small space for large volumes. Here is a brief description of how rotary drying works:

Wet product is brought into direct contact with a hot air stream that is generated from any number of fuel sources. The wet product and hot air are drawn into a rotating dryer drum. The hot air stream dries and conveys the product in a concurrent process. The drum is equipped with internal longitudinal lifting flights that repeatedly drops the product into the axial air stream. As the product dries inside the drum it advances towards the collection system for the dried product.

The desired outlet moisture of the product is obtained by controlling the drum outlet air temperature, modulating the fuel control system as required. The heat source is modulated on the infeed side of the dryer. As the amount of product and moisture in the drum increase, the inlet temperature increases accordingly to satisfy the heat needed to dry the product effectively.

At the discharge end of the drum, the dried product is conveyed into cyclones where the product is separated from the airstream and discharged.

After the cyclones, the airstream is ducted to an induced draft fan. The fan creates a suction on the system that has two functions: to pull the heat from the burner through the drum and to advance the product in the rotary drum. duct dries inside the drum it advances towards the collection system for the dried product.

As also seen in Powder & Bulk Solids.

Illinois, Wisconsin universities team up to test different hemp varieties with farmers’ help

Illinois, Wisconsin universities team up to test different hemp varieties with farmers’ help

July 15, 2020

The University of Illinois and the University of Wisconsin are recruiting Midwestern farmers to plant and test different varieties of hemp this year in exchange for discounted cannabinoid sampling.

Project participants must agree to at least two sampling dates per plant variety for collection into the Midwestern Hemp Database. The University of Illinois Extension says that as a new crop to the Midwest, “best management practices (BMPs) and varietal performance of industrial hemp have yet to be determined.”

Best practices for managing wood fibre storage and combustible dust


Best practices for managing wood fibre storage and combustible dust

By Fahimeh Yazdan Panah | June 23, 2020

Combustible wood dust in confined storage could present a risk of fire and explosion if it’s not managed effectively. The Wood Pellet Association of Canada (WPAC) has developed tools to improve safety and lower the risk when working around wood fibre storage.

In 2017, the Wood Pellet Association of Canada (WPAC)’s Safety Committee, in collaboration with the BC Forest Safety Council (BCFSC), the Manufacturing Advisory Group and WorkSafeBC, established a Working Group to lead the process on developing best practices for combustible dust management in wood fibre storage. This collaboration resulted in the formation of the Wood Fibre Storage Working Group (WFSWG), with the overall objective of improving safety within the wood manufacturing sector by eliminating injuries and fatalities.