Speed manages streams

Gibson, Ian; Irvine, Geoff
July 2004
InTech;Jul2004, Vol. 51 Issue 7, p33
This article discusses the concept of using variable frequency (VF) drives to control electric-driven centrifugal pumps. Some of the advantages of using VF drives on electric motors are energy savings, efficiency, power factor, installation, specification, ability to control, maintenance, fugitive emissions, and reduced wear on the bearings and seals of the pumps. Discharge throttling is widely applied in the petroleum industry. It involves putting a control valve on the discharge side. The speed control method of flow control ensures that just enough energy goes to the pump to get the desired flow rate. The most common method of controlling the frequency is pulse width modulation. Direct on line starting a pump may cause water hammer effects, as this method makes no attempt to soft start the pump. Cavitation is a phenomenon that occurs whenever the static pressure drops below the liquid vapor pressure. Reducing the speed of a pump reduces the wear on the seals and bearings of the pump. This is verifiable by examining the reliability index of a pump manufacturer. Where digital communications are communicating speed reference signals and configuration data to the drive, it brings benefits to the overall operation of the plant.


Related Articles

  • Modeling and Analysis of Sealing Ring Cavitation in Pumps with Water and Oil. Nair, K. Gangadharan; Babu, T. P Ashok // International Journal of Dynamics of Fluids;2008, Vol. 4 Issue 1, p13 

    This research paper presents a method developed for modeling and analyzing sealing ring cavitation in centrifugal pumps handling water as well as oil. The paper aims at theoretical formulation for sealing ring cavitation and analysis by simulation using data obtained from a typical centrifugal...

  • Let Your Pumps Talk. Bachus, Larry // Flow Control;Feb2012, Vol. 18 Issue 2, p32 

    The article presents the author's views on pumps, like centrifugal pumps, based on his experiences. The author recalls one of his experiences of speaking at the Pump Guy Seminar in Michigan. He states that if a pump manufacturer comes out with a new product with an original design or concept,...

  • Numerical Calculation of the Three-Dimensional Swirling Flow Inside the Centrifugal Pump Volutes. Nursen, E. Cezmi; Ayder, Erkan // International Journal of Rotating Machinery;Jul2003, Vol. 9 Issue 4, p247 

    The flow inside the volute of a centrifugal pump is three-dimensional and, depending upon the position of the inlet relative to the cross-section center line, a single or double swirling flow occurs. The purpose of this study was the calculation of the three-dimensional swirling flow inside the...

  • Prime application.  // International Construction;Nov2005, Vol. 44 Issue 9, p33 

    The article presents information about the different type of pumps, such as, centrifugal, high-pressure, submersible which are available in the market. All centrifugal pumps use an impeller and volute to create the partial vacuum and discharge pressure necessary to move water through the casing....

  • Sealing of Gland Systems of Pumps Using New-Generation Sealing Materials. Avdeev, V. V.; Il'in, E. T.; Ulanov, G. A. // Chemical & Petroleum Engineering;Sep/Oct2003, Vol. 39 Issue 9/10, p612 

    This article focuses on centrifugal pumps having seal gland systems. Lately, sealing materials based on heat-expanded graphite and various modifications of polyterafluoroethylene are gaining increasing application. Packings from these materials meet almost all of the above-listed requirements,...

  • Precisioned Out Of a Job. Bachus, Larry // Flow Control;Nov2006, Vol. 12 Issue 11, p32 

    The article presents the author's answer to queries related to flow control in pumping machineries. The author says that very few centrifugal pumps operate for more than a few seconds at their rated flow and head as they perform an operation. According to the author, there are some critical...

  • CHAPTER 39: CENTRIFUGAL PUMPS.  // ASHRAE Handbook: Heating, Ventilating & Air-Conditioning Systems;2004, p39.1 

    Chapter 39 of the book "2004 ASHRAE Handbook: Heating, Ventilating and Air-Conditioning Systems and Equipment" is presented. It offers information about the construction features of a typical centrifugal pump which vary according to the manufacturer and the type of pump. It gives an account of...

  • How To Select A Centrifugal Pump. Frankel, Mike // PM Engineer;Jan2011, Vol. 17 Issue 1, p20 

    The article offers information on selecting a centrifugal pump. Definitions are provided for key pump-related terms, including affinity laws, best efficiency head (BEH) and best efficient point (BEP). A centrifugal pump is described as a non-positive displacement and dynamic machine that...

  • Know your pumps. DeLoatch, Bruce // Cleanfax Magazine;Sep2007, Vol. 22 Issue 9, p22 

    The article focuses on several pump systems. A pump system for hot water extraction raises, delivers, transfers or compresses liquids or gases by suction or pressure, or both. Two of the basic and most common types of fluid pumps are centrifugal and positive displacement. Centrifugal pumps are...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics