So you’ve decided you need baffles for your tank. Before you start welding, are you sure you’ve got the right size baffles? Baffles that are too large in proportion to the tank diameter may cause dead spots near the trailing edge of the baffle, while baffles that are too small will not disrupt the fluid in the tank enough. How do you calculate just the right size?
Sometimes, especially in round tanks with center mounted industrial mixers, baffles are needed to ensure the proper mix is being achieved. They prevent fluid inside the tank from gaining a swirling momentum, and also promote top to bottom movement of the fluid.
Proper Baffle Sizing / Placement
All it takes is a little simple math to find the right sized baffle. The width of the baffle should be 1/12 of the tank’s diameter. So with a tank that’s 100” wide, an 8” baffle is needed.
What about placement? Just how far away from the wall should the baffle be placed? The baffle shouldn’t be welded tight to the wall of the tank.
Offset the baffle from the wall of the tank by 1/3 the size of the baffle’s width. Again, in our 100” wide round tank with an 8” baffle, the baffle should be offset about 2.5” from the wall.
Baffles should also be installed about 6” from the bottom of the tank, and reach just over the maximum liquid level.
Thickness and supports for the baffles is usually determined by the tank manufacturer. If you're interested in learning more about this, check out Cleveland Mixer's take on the topic.
Number of Baffles
How many baffles should you install? Typically 4 is ideal, however 3 baffles will most often achieve the desired result. When it comes to number of baffles, more isn’t always better. Adding more than 4 baffles doesn’t give much improvement.
The End Result
Baffles and their configuration can have a significant impact on industrial mixing efficiency. Their addition can reduce mixing time, and also yield a better product. If you’re still uncertain how to apply baffles to your mixing process, contact a qualified engineer to work through it. They can take a closer look at the fluid, tank, and equipment involved to give you a recommendation.
Not sure if you need baffles, or if you have the right size? Ask us about it! We gladly provide technical assistance to businesses and municipalities in Wisconsin and upper Michigan.