With the wide use of variable frequency drives in the pump industry and increasing unit size, it is becoming more difficult to design mechanical systems free from natural frequencies within operating speed range. If such an occurrence is allowed in the field, a resulting resonance condition threatens to significantly impact performance and longevity of the equipment.
In the oil and gas industry, custody transfer transactions involve transporting physical substance from one operator to another, including transferring raw and refined petroleum between tanks and tankers, tankers and ships and other transactions. An accurate account of the amount of material transferred is of great value to both the company delivering the material and the eventual recipient. This is especially true in bunker fuel oil delivery since a ship's bunker contributes to the ship's operating cost.
Back in the old days, level control had little or nothing to do with saving energy. In fact, it was often a necessary evil. Today, that is no longer true - the VFD offers the potential for power savings in lift station applications that range from a few hundred gallons per minute to those that have to move thousands of gallons each minute.
Growing infrastructures are creating more complex problems for municipalities than ever before, forcing them to search for a diverse range of system solutions to issues involving energy savings, maintenance savings and total life cycle cost analysis.
What Are Your Vibration Monitoring Goals?
Identifying goals before starting is key to designing a process tailored to specific needs. What are you hoping to accomplish by monitoring vibration? How would you like to acquire data? What are you going to do with the data? These important questions should be addressed before moving forward.
Your company has recently purchased a laser based alignment system. Your newly trained technicians are asked to align a critical process pump. You witness the alignment. They save the final alignment data. You review the data, but what does it mean? How does it compare to dial indicators? Why did they rotate both shafts when measuring the misalignment? Why are the numbers at the feet higher than you would like? How do you KNOW the alignment is good? The debate begins.
Joseph Gallo Farms in Atwater, Calif., uses captured methane gas from its 5,000 dairy cows to run up to 50 percent of the electricity for its cheese factory.
A variable frequency drive (VFD) can be a valuable asset in reducing the life cycle costs in certain types of pumping applications. The traditional method of motor control in pumping applications is a low cost mechanical starter, which is essentially a large switch with a built-in motor protection device known as a thermal overload relay. A conscious decision to reduce upfront costs by using a mechanical starter may result in higher energy consumption, excessive component wear and poor power quality.
Water chemical compatibility and electrical interference are two major challenges for control systems. Two major sources of fresh water can limit the performance of the control system.
Potential to Failure (P-F) curves graphically display the failure time cycle and measurement techniques that can be used to detect asset failures prior to reaching the asset incurring functional failure. Proactive strategies should focus on managing assets high on the P-F curve, or early (P1 to P5) in the failure cycle (Figure 1). The ability to detect failures early in development allows top quartile performers to proactively manage their maintenance programs by understanding the health of their assets. Many companies, however, find it difficult to operate proactively and continually react to assets that reach functional failure with little or no warning.
To explain why the apparent temperature seen through a thermal imager can be significantly different than the actual temperature, we will review our knowledge of physics.
Outdated water systems are pumping beyond their original specifications, resulting in inefficient operation, higher maintenance and operation costs and the potential for a system shutdown. This article takes a look at updating the controls and pumps for a water system.
In recent years, adjustable frequency AC drives have become increasingly popular as they provide an efficient, direct method of controlling the speed of the most rugged and reliable of prime movers, the squirrel cage motor. They provide a spectrum of benefits for a broad range of applications.
Few would dispute that variable frequency drives (VFDs) save energy, but the exact amount depends on the system. Hydraulically speaking, the main difference between a variable frequency (speed) drive and a discharge valve is that a VFD only changes a pump curve, while a valve only changes a system curve. A pump operates at the intersection between its H-Q curve and a system curve, and a change in either moves the operating point to a new intersection.
Frequency Hopping Spread Spectrum (FHSS) radio was invented during World War II by the military for communicating information and strategic plans to allied forces in a way that would counter enemy efforts to "jam" or intercept traditional radio communication frequencies.
For controller-to-controller coordination, wireless Bluetooth is an excellent alternative to Class 3 radios.
Enveloping is a tool that can give more information about the life and health of important plant assets. It is primarily used for early detection of faults in rolling element bearings and gearboxes. Enveloped acceleration is an especially valuable parameter to trend, as the progression of machine condition can be evaluated. Armed with good information and assisted by service experts, plant engineers can be confident in the proper operation and management of the important assets in their care.
In the last decade, ultrasonic flowmeters have grown in popularity in laboratory and process areas as a cost-effective, noninvasive alternative for measuring the velocity and flow rates of liquids and gases.
Have you ever wondered why a motor manufacturer would state that many of their 60-Hz motors will operate on 50-Hz power as long as you reduce the nameplate voltage by 1/6?
The Detroit Water and Sewerage Department (DWSD), a municipally owned utility, provides roughly four million residents in southeastern Michigan with an average of 710 million gallons of water per day.