When you’re presented with various types of industrial pumps, it can be confusing to select the one that’s the best for your project needs. We’re going to take a look at what industrial pumps are and how they can be used to maintain a smooth and problem-free operation.
About Industrial Pumps
Industrial pumps are used in a wide variety of applications across many industries in Australia. These devices are usually heavy-duty process pumps which are used to move water, chemicals, petroleum, wastewater, slurry, oil and food. There are basically two types of pumps typically used for industrial purposes: centrifugal pumps and positive displacement pumps.
Types of Industrial Pumps
Positive Displacement Pumps
There are a vast range of pump types. These include piston pumps, diaphragm pumps, screw pumps, gear pumps [internal and external], lobe pumps, peristaltic pumps, progressive cavity pumps, and many others. We will however, concentrate this article on the centrifugal industrial pump.
Centrifugal Pumps
Centrifugal pumps are the most common pump in use today. They use a rotating impeller to accelerate a fluid and increase its pressure. Centrifugal pumps can be standard [also called end suction], submersible, or self-priming. End-suction centrifugal pumps are the most prolific in process because of their relatively inexpensive construction and the huge variety of materials and specialisation available.
Submersible pumps have been the default choice in wastewater for several decades because of their lower initial cost, but as the cost of implementing safety systems and controls increase, some may look for more sustainable long-term solutions. Many submersible pumps are also adversely affected by water above 40OC, which may cause issues where high temperature hot water or steam cleaning is used by processing plants.
Standard centrifugal pumps can also be used in wastewater, but the costly construction of “dry wells” to house them has reduced their use over time.
Self priming centrifugal pumps are being increasingly used by industries around the world as asset owners and engineers look at the increasing cost of maintaining these “conventional pump” assets, as well as the increasing cost of safety protocols associated with working on and around these assets.
Industrial Pumps and the Hierarchy of Controls
There are numerous risks that operators face in maintaining industrial pump assets. In a survey conducted by Hydro Innovations, the following risks were highlighted by industry operators:
- Working over water
- Working at heights
- Working with heavy swinging weights
- Working with cranes
- Working in confined spaces
Whenever chokes need to be removed, pump maintenance needs to be done or guide rails or discharge bends need attention in the “conventional” system, the risks require the increased participation and supervision depicted in the above diagram. Those choosing self-priming pumps have eliminated these risks.
While there is increased costs associated with increased participation and supervision, there are “hidden” costs associated with operating “conventional” systems.
– Power consumption. A submersible pump is losing efficiency from day one, and the only way to get “factory settings” back to worn wear rings is to replace them or adjust clearances. Until then, pumps are not delivering their published efficiency. Getting back to published efficiency requires a submersible pump to be removed from the wet well [with a small crew and a crane]. Until this is done, costs are “leaking” from the system. This is something that is not noticed immediately. Pump cycles will continue to lengthen gradually, over time, wasting energy along the way, until the pump cycles become so long, someone notices.
– Again on power consumption, all submersible pumps rely on the sealing between the pump and the discharge bend. This may be all fine on “Day 1”, but at some point in time, that metal to metal “seal” will wear, and begin leaking. After leaks start, they get larger as more material passes through that point. Also, as pumps get lowered back onto discharge bends, they may not always seat properly [because of foreign matter], again causing leaks.
– All lifting chains for these submersible pumps need to be rated/certified. They need to be inspected or replaced every single year. This may not be a huge cost for one set of chains for one pump, but the cost to replace these chains on multiple pumps every year, over several years, adds up.
– Some production plants have their own lifting apparatus to raise submersible pumps out of wet wells, but others need to rely on 3rd party contractors with crane trucks. This could be a yearly event [or more often if blockages occur], coming at a high cost.
– The number of personnel needed to provide maintenance services on submersible pumps is also a factor often overlooked when assessing how much it will cost to maintain an asset.
– And if a submersible pump needs to be accessed while still in the wet well [stuck on guide rails or broken lifting chain or replacing discharge bends, a very expensive and dangerous confined-spaces entry will be necessary.
Selecting the Right Self-Priming Pump – For Wastewater
Self priming pumps are mounted on the surface at ground level, with only the suction lines entering the wet well. Wet well lids remain closed for all routine maintenance events [such as oil changes, clearance adjustments, valve greasing], and even major overhauls are all done with the wet well lids sealed. All mechanical and electrical equipment is mounted at ground level. This does make them substantially safer to operate than submersible pump systems.
If the decision has been made to install self priming pumps because of safety or maintenance cost savings, selecting the right one is important.
Some considerations effecting the selection include:-
– Pressure
– Suction lift
– Suction line size
– Suction line submergence
– Solids in the fluid
– Chemicals in the fluid
– Temperature of the fluid
– Safety features of the pump
– Maintenance features of the pump
These are just some of the factors to consider when selecting a new industrial pump, as well as when configuring an effective pump system that will hopefully last you many, many years to come—no matter what materials you are pumping every day.