classic | mobile
 

Search...

SA Instrumentation & Control Buyers' Guide

Technews Industry Guide - IIoT 2018

Technews Industry Guide - Maintenance, Reliability & Asset Optimisation

 

Non-invasive optimisation at a BP refinery
September 2011, Mass Measurement


The many processes running in a refinery form a highly complex system of material and energy flows that can only be managed by means of a dense network of measuring points recording all relevant parameters. Rising energy and resource costs means that measurement and control technology must now more than simply ensure that a plant fulfils its function, a constant optimisation of the plant’s processes is required. In the field of crude oil distillation, an important indicator for efficient column operation is the overflash volume. The properties of the medium – a heavy and highly viscous gasoil – and the process conditions (low flow velocity and high temperatures around 380°C) make it very difficult to measure this accurately.

The BP oil refinery Emsland processes about 4 million tonnes of crude oil annually. But not all crude oil is equal, its composition, and thus the percentages of light and heavy hydrocarbons varies depending on its origin. The process control has to respond flexibly to these differences in order to achieve the highest possible yield of desired products.

Difficult measurement

Usually, refinery plants use orifice flowmeters because of the high temperatures. At Emsland, the overflash volume is conveyed in a 150 mm pipe located on the outside of the column. Measurements using the differential pressure method are particularly difficult due to the low volume flow. For orifice flowmeters, this means that an orifice plate with a very small diameter would have to be used to obtain satisfactory precision.

After a test had demonstrated the suitability of non-invasive ultrasonic technology for this application, a system from Flexim, was installed: a Fluxus meter with WaveInjector that uses the transit time difference principle to measure volume flow. Since the physical conditions at the measuring point are virtually constant, it is easy to calculate the mass flow without recording the pressure and temperature. The recorded values are fed into the process control system and are used for optimising control tasks.

High temperature flow measurement with the WaveInjector

Flexim’s WaveInjector extends the possible application range of non-invasive ultrasonic measurements to temperatures up to 400°C. The system consists of two coupling plates, each connecting a transducer with the pipe, yet keeping both of them a certain distance apart. The surface of these plates radiates enough heat to keep the temperature at the mounting point of the transducers within the permissible range. Simultaneously, the coupling plates ensure the acoustical contact between pipe and transducer. The mechanically robust mounting fixture maintains a high contact pressure and specially designed metal foils eliminate coupling gel and ensure optimal contact and long-term stability.

As the WaveInjector is a purely mechanical arrangement, it can also be used in explosive atmospheres, together with transducers that have been tested and certified for explosion protection. It is not necessary to cut into any pipes to install the transducers; they can be retrofitted without downtime or complicated approval procedures.

Process optimisation

The optimisation of systems and processes at the refinery is becoming increasingly important with software for advanced control implemented for this purpose. It varies the process parameters based on mathematical models and data from the process control system and optimises the process using iterative learning control. An important process value for this purpose is provided by the high-temperature ultrasonic measurement at the overflash return line. As reliable data is now available on the quantities that return as a function of the various types of crude oil and of the way the column is being run, the process can be optimised for energy efficiency and yield.

WaveInjector opens up new areas of application for non-invasive technology where exact flow measurement is difficult. Determining the overflash quantities in the distillation of crude oil is only one example. Petrochemical processes typically involve high temperatures and highly viscous media. In this area, non-invasive measurement with the WaveInjector is very popular, eg, for flow measurements of tar or bitumen.

For more information contact Peter Jones Electronic Equipment, +27 (0)11 608 2944, expediting@peterjones.co.za, www.peterjones.co.za


Credit(s)
Supplied By: Peter Jones Electronic Equipment
Tel: +27 11 608 2944
Fax: +27 11 608 3825
Email: sales@peterjones.co.za
www: www.peterjones.co.za
Share via email     Share via LinkedIn   Print this page

Further reading:

  • Mechanical density meter
    July 2018, Instrotech, Mass Measurement
    Whether dealing with the concentration or the mixing ratio, the density of liquid media is of high importance in processes such as the food or chemical industry. Kobold’s DWF mechanical density meter ...
  • Mettler Toledo’s weighing control terminal for chemical processes
    May 2018, Microsep , Mass Measurement
    Profinet interface added to Mettler Toledo’s popular weighing control system.
  • Proline Promass Q 300/500
    February 2018, Endress+Hauser, Mass Measurement
    The specialist for challenging applications with superior accuracy for mass, volume flow and density determination.
  • Increased whisky production with Yokogawa’s Coriolis mass flowmeter
    January 2018, Yokogawa South Africa, Mass Measurement
    The James Sedgwick Distillery was established in 1886 and is situated in the picturesque region of Wellington in the Western Cape. The distillery produces both malt and grain whiskies on the same site, ...
  • Every drop counts
    October 2017, Yokogawa South Africa, Mass Measurement
    Yokogawa’s bespoke custody metering solutions.
  • Precision indicator for belt weighing applications
    June 2017, Loadtech Loadcells, Mass Measurement
    Loadtech’s LT1320 is a precision digital indicator for belt weighing applications. The unit takes the weight and speed information from a belt conveyor system and accurately calculates the rate and ...
  • A unified transmitter platform
    Africa Automation Fair 2017 Preview, Yokogawa South Africa, Mass Measurement
    Yokogawa’s Rotamass TI product family has a common and unified transmitter platform with two options. The Essential transmitter is the cost-effective solution for general purpose applications, and the ...
  • Radiometric density detector
    Africa Automation Fair 2017 Preview, Mecosa, Mass Measurement
    The SmartSeries LB 414 radiometric detector for density, concentration and solids content measurements combines both detector and evaluation in one single unit. It can be used in all liquids and slurries. ...
  • Flow measurement and regulation by mass
    February 2017, Instrotech, Mass Measurement
    Kobold has introduced its DMS digital flowmeters that, because they record the mass of gases, are unaffected by the pressure and temperature of this medium. The measuring devices work using a bypass capillary ...
  • Mettler Toledo’s weighing control for chemical processing
    December 2016, Microsep , Mass Measurement
    Profinet interface added to Mettler Toledo’s popular weighing control system.
  • Digital indicator for material transfer applications
    November 2016, Loadtech Loadcells, Mass Measurement
    Loadtech’s LT1320 is a precision digital indicator for belt weighing applications. The unit takes the weight and speed information from a belt conveyor system and accurately calculates the rate and total ...
  • High-pressure Coriolis flowmeter
    October 2016, Instrotech, Mass Measurement
    High-pressure processes for chemical injection systems, for example on oil drilling rigs or offshore platforms, are a challenge for any flow measurement system. Chemicals added by injection through a ...

 
 
         
Contact:
Technews Publishing (Pty) Ltd
1st Floor, Stabilitas House
265 Kent Ave, Randburg, 2194
South Africa
Publications by Technews
Dataweek Electronics & Communications Technology
Electronic Buyers Guide (EBG)

Hi-Tech Security Solutions
Hi-Tech Security Business Directory

Motion Control in Southern Africa
Motion Control Buyers’ Guide (MCBG)

South African Instrumentation & Control
South African Instrumentation & Control Buyers’ Guide (IBG)
Other
Terms & conditions of use, including privacy policy
PAIA Manual





 

         
    classic | mobile

Copyright © Technews Publishing (Pty) Ltd. All rights reserved.