We use pumps every day. But do we know how pumps work? From watering our lawns and keeping our pools functional to cooling our homes and fueling our cars, pumps have countless common applications. But the specifics of their function escape most of us. And did you know that pumps feature heavily in industry — almost every industry in fact! Construction, manufacturing, medicine, agriculture, chemical production, and food service are just a few of the areas where pumps play an important role.
Because pumps have existed for many centuries, this introduction to pumps could easily get too expansive. So instead of detailing what all of their various types and configurations are, we will focus on centrifugal pumps in general (one of the most common kinds of pumps) and magnetic drive centrifugal pumps in particular. This Pumps for Beginners Guide will detail how they work, their advantages, and their real-life applications.
How Do Magnetic Drive Pumps Work?
When broadly speaking about pump types, you should know that centrifugal pumps fall into a wider category called dynamic pumps. Unlike positive-displacement pumps (which add energy in periodic spurts), dynamic pumps input energy continuously in order to move the fluid or slurry that’s being pumped. The specific kind of pump we’re considering does so through a kind of continuous centralized movement, hence the name “centrifugal.”
Pumps have three essential parts: their casings, their impellers, and an attached motor. (Note the use of the word “attached.” Not all pump types are attached in the way you might think, but we’ll get to that a little later.) The impeller is the component that creates the centrifugal force that will eventually move the liquid through the pump. The casing keeps that force contained, transforming force into pressure, and moving the desired liquid.
You’ll find countless kinds of casings and impellers, each designed for a different kind of application. Some feature horizontal split casings that allow users to easily pop the top off and inspect the pump when needed. Self-priming pumps create an internal vacuum to make for easier starting and operation, and some pump types can even move liquids containing a significant amount of solid material. Then there are magnetic drive pumps, which are the sorts of pumps March Pumps manufactures.
If you’ve seen the inside of a centrifugal pump, you understand how the impeller is connected to the drive by some sort of shaft. This is called a direct drive pump. A magnetic drive pump, though, doesn’t work that way. Instead, a bracket holds the impeller shaft in place, and the shaft doesn’t come into contact with the motor. How does the motor rotate it, then? Through magnetic force. A drive magnet attached to the motor syncs up with a magnet connected to the impeller, causing it to spin.
Advantages of Magnetic Drive Pumps
Magnetic drive pumps may initially sound overly high-tech and complicated. It’s true that magnetic drive pumps can cost more than traditional centrifugal pumps. However, they come with a number of distinct advantages.
For one thing, magnetic drive pumps don’t have a shaft seal (also called a mechanical seal), the leak-proof seal that’s supposed to keep liquids from leaking out of the pump. Why? They don’t need one. Because a magnetic drive pump’s impeller is only suspended on an internal bracket, it never actually comes in physical contact with the motor shaft. Magnetism eliminates that need — and also eliminates the need for the shaft seal itself.
To someone who isn’t an expert, this may seem like an insignificant difference. It isn’t. Any moving part in any machine runs the risk of failure, and when dealing with industrial pumps, the consequences can become severe. One great advantage of a magnetic drive pump lies in the elimination of maintenance and downtime. This saves direct costs and prevents lost revenue from lulls in production.
The elimination of a shaft seal in the magnetic drive design has other implications that we will delve into in the following section: It allows end users to much more easily manage caustic and corrosive substances.
Magnetic Drive Pumps’ Function
Leaks do more than merely impact a company’s bottom line. When you’re attempting to pump a dangerous chemical, a leak can put lives and property at real risk. It also can create an environmental hazard with all the concomitant regulatory action and fines that phrase entails.
Fortunately, a magnetic drive pump’s encapsulated construction practically negates the chance of leaking. This facilitates the easy pumping of extremely dangerous substances. That being said, you’ll need to consider one more element: the construction of the pump’s casing.
Even though the absence of the shaft seal makes for a safer pump, leakage risk can still exist. Why? Not all casing construction materials can tolerate contact with different types of substances and chemicals. As we’ve mentioned in a previous blog post, end users need to pay particularly close attention to the types of fluids and chemicals they’ll be pumping. Next, they must consider the concentration (i.e., strength) of that liquid. And finally, they must take into consideration the temperature of the pumped chemical.
That may seem like a lot to consider. Fortunately, we’ve compiled a list of commonly pumped chemical solutions, materials as diverse as hexane, lactic acid, magnesium hydroxide, nitriobenzene, pyridine, milk, and olive oil. We then cross reference them according to suitability with pump casing materials such as:
- 316 Grade Stainless Steel
- Hastelloy “C”
Centrifugal pumps real-life applications
The magnetic drive pumps designed by March Pumps find uses in a wide array of real-life applications. Did you know you can find our pumps in commercial-grade ice-making systems that require chemicals such as saltwater, ammonium sulfate, sodium chloride, and acetone? Were you aware that we help facilitating the chemical toting (i.e., repackaging bulk amounts into smaller lots) of sulfuric acid, acetic acid, phosphoric acid, and formaldehyde? Our pumps appear in industries as diverse as hydrotherapy and metal pickling, bio-fuel and battery manufacturing, artificial-limb manufacturing and aquariums.
March Pumps has been in business since 1954. Are you looking for a pump for your business or factory? Contact us via phone (847) 725-0580 or through our online form to learn how we can help.