When it comes to pressure and flow, variable speed pumping applications can be divided into three basic categories. Constant pressure-variable flow (Cp-Vf) attempts to keep pressure relatively constant over a range of flows. Constant flow-variable pressure (Cf-Vp) tries to achieve the opposite by using varying pressure to keep flow constant. Variable pressure-variable flow (Vp-Vf) applications can accommodate a change in both.
Most VFD systems use some form of closed-loop feedback to avoid surging, excessive noise, and in extreme cases, vibration. A reliable encoder signal is one method that minimizes speed variance and helps eliminate these unwanted effects. Here's how it works.
Why is "run to fail" a common operational strategy at water/wastewater organizations? Explore this phenomenon and other results from a maintenance methodology survey.
The Merchandise Mart in Chicago, Ill. is the world's largest commercial building, largest wholesale design center and a premier international business location. Encompassing 4.2 million gross square feet, the Mart spans two city blocks and stands 25 stories high. It welcomes more than three million visitors each year to its retail shops; boutiques; 11 floors of permanent showrooms for gift, residential, casual and contract furnishings; 10 floors of office space; dozens of trade shows and a myriad of special educational, community and consumer events. pump system optimization
In the power industry, clean water is crucial for a variety of tasks, including extending the service life of turbine seals and protecting spray nozzles and heat transfer equipment. Raw water drawn from lakes, rivers and reservoirs must first be strained to create acceptable clean water for use. The power industry and other industries must continuously strain tens of thousands of gallons of water per minute to remove dirt and debris that can wreak havoc on critical process systems and equipment.
Applications for electric power and the Smart Grid
As pump users, we often have to deal with fuzzy concepts, such as: What is low flow? When are vibration levels too high? When is suction specific speed value too high? When is a pump's energy level high?
Many reasons for wireless conversion reluctance are resolved with new technology.
Last month, we looked at adjustable frequency AC drive system, induction motor speed control and motor application and performance. This month we will explore specific operation conditions, applications and performance.
Holistic pump system designs optimize system efficiency and life cycle performance.
Over the past 50 years, advances in technology have provided the primary thrust behind the success and evolution of variable-speed drive systems. Here are some considerations for the proper selection and set up of different types of systems, and what lies ahead in the future.
Last month, we discussed thermal radiation and material properties and the thermal nature of materials. We also looked at the emissivity of real objects using a stainless steel block. This month, we will discuss other characteristics demonstrated by the steel block example.
To achieve a sustainable future, the green movement demands increased energy efficiency and conservation. Here is a look at how these changes will impact the water industry and its use of pumps and controls.
With the old mechanical displacers, level fluctuations ran 4-in to 5-in with a lot of hysteresis and frequent failures, causing operators to control at much higher levels than were optimal. New magnetic technology is changing all that. Here's how.
Find out why level controls can fail in municipal wastewater treatment plants and similar systems and what technologies are available to combat failure.
You have probably noticed that there are several camps out there when it comes to centrifugal pump applications involving variable frequency drives (VFDs). One group believes that every pump should have one, while another thinks that they should be banned altogether. And, of course, there is the middle ground that says it depends upon the pump and application. pump system optimization, pump efficiency
This municipal water system evaluated the cost of upgrading their existing SCADA software and decided it was time to consider replacements. After much research, it became clear that not only was it possible to get all the features they were missing; they could also do most of the configuration in-house.
Today's lean maintenance staff needs pump and motor protective devices that diagnose and predict problems before they become acute.
Named after frontiersman Kit Carson, Carson City, Nev., is known for its fresh air, rugged natural surroundings and its proximity to the casinos of Reno and skiing in Lake Tahoe. Carson City, the capital of Nevada, has been a self-governing municipality since 1972. The Carson City Public Works Dept. manages all the water for Carson City and County. Its mission is to be completely self-sufficient-acquiring, using and reusing 100 percent of its own water.
Effective and secure cellular communications for remote data acquisition