Are you in the process of choosing a new screw conveyor? Before you nail down the specifics of the machine you wish to purchase, you’ll need to figure out the screw conveyor sizing. Of course, calculating the desired size of your screw conveyor is nothing like measuring for a new piece of furniture. Luckily, most screw conveyor manufacturing companies will help you figure out the correct capacity, screw diameter, and trough loading specifics, but knowing more about the calculation process can help you communicate more effectively with the design engineers.
Screw Conveyor Sizing
Flow Rate and Screw Size
Since the purpose of a screw conveyor is to move product from point A to point B, you’ll want to determine how fast you want the product to move (this is called the flow rate or capacity). Of course, a screw conveyor can only hold so much material at one time, but the bigger the screw inside the conveyor and the lighter the material, the faster the machine can work. The capacity of a screw conveyor is measured in cubic feet per hour.
When calculating screw conveyor sizing, manufacturers look at the desired flow rate, the diameter of the screw (the part where the blades extend), the outside diameter of the center pipe, the pitch of the screw (the distance between each blade on the screw), and the trough loading percentage.
Another very important factor in determining the overall screw size is the actual size of the product to be moved. It is very important to determine both the minimum and maximum size of the products that will be conveyed. Make sure and share that information with your screw conveyor manufacturer during the specification portion to ensure they will help you select the proper size screw for your application.
The Conveyor Equipment Manufacturers Association (CEMA) has the formula to calculate the amount of product the screw will convey each time it rotates. If you are working with a reliable manufacturing company, they will have a capacity calculation formula in their screw conveyor design software.
Trough Loading and Sizing
The recommended trough loading corresponds directly with the screw conveyor’s capacity and the type of material it must process. Ideally, you shouldn’t load the trough more than 30 percent if you are working with an abrasive, thick material in a screw conveyor with an average or fast capacity. You’ll also need to reduce the speed of the screw conveyor when processing dense materials. Luckily, you don’t need to worry about learning each formula for screw conveyor sizing. The manufacturing company you’re working with should be able to tell you how full you can safely load the trough depending on material density and machine capacity.
Look for Variable Frequency Drives and Operating Voltages
If you plan on using your screw conveyor for processing more than one type of material, make sure to work with a company that creates machines with variable frequency drives and operating voltages. This will allow you to work with material that is dense or even more lightweight. Another feature that will make your screw conveyor more versatile is variously sized infeed hoppers. You deserve to get the most out of your machine, so make sure you have the flexibility to work with different products.
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If you’re in the market for a new screw conveyor, contact EnSight Solutions. We design our rugged, powerful screw conveyors with the highest level of sanitation and safety standards in mind. We believe that your unique facility deserves a unique machine, so we’ve made it our goal to provide you with as many optional features as possible.
With more than 100 years of combined experience in the food processing industry, we are committed to finding creative, effectual solutions to fulfill our clients’ equipment needs. We offer a variety of food-grade conveyors, including storage loader conveyors, spreading conveyors, screw conveyors, and belt conveyors. When you’re ready to get started, please send an e-mail to info@ensightsolutions.us, give us a call at 1-855-736-2195, or find your EnSight sales specialist through our contact page. We look forward to hearing from you!
