Alternatives to Impact Weighers for Solids Flow Measurement Print
Written by Martin Juleff   
Tuesday, 02 February 2016 06:26

Alternatives to Impact Weighers for Flow Metering

Is your impact weigher requiring maintenance, not giving accurate flow readings, or perhaps it's just not working. There may be an alternative! Read on to find out more about our non-contact flow meter for solids

Impact weighers, like belt weighers, are routinely used for applications requiring continuous mass flow measurements, such as monitoring the flow rate of product in a process, or batching a product out of a bin.

Impact Weigher Operation Diagram

An impact weigher uses an impact plate that is placed into the process stream. Sensitive strain gauges measure the force of the dry bulk material colliding with the impact plate, and this measurement is then converted into a continuous flow rate.

As you can imagine, impeding the flow of powder can lead to several undesirable side-effects such as premature wear of the instrument, and damage to the sensors when material surges occur. There are more disadvantages of mechanical flow rate systems such as impact weighers, however many of these can be overcome with clever and innovative ideas to reinvigorate an ageing technology. These innovations can quickly add up and increase the price of the more advanced impact weighers, making them an expensive proposition for solids flow metering.

Whenever something becomes too complex, we at Semrad feel it is sometimes best to go back to the drawing board and come up with a simpler alternative.

MF-3000, Non-Contact Solids Flow Sensor

A simpler solution might look a little something like this (pictured left). This is the MF-3000 bulk-solids flow metering system. The MF-3000 is a non-contact mass flow meter specifically designed for measuring the flow rates of dry materials such as powders, dust, granules and pellets in freefall and pneumatic pipeline conditions. The MF-3000 utilises the latest microwave technology to accurately measure the flow rate of bulk materials, from a few kg/hr to multiple t/hr. Using a non-contact technology means the device is free from mechanical wear and tear an impact weigher would be subject to.

MF-3000 Installation Diagram

While a non-contact device is free of wear and tear, they are often subject to other issues such as build-up blocking the sensor, however the MF-3000 uses high frequency microwaves that can effectively penetrate build-up, making this a non-issue for this sensor. The actual measurement uses the Doppler effect to essentially “count” the particles flowing past the sensor by measuring the changes in the wavelength and frequency caused by moving particles. This means stationary particles will not affect the flow rate being measured.

Impact Weigher vs Non-Contact Flow Meter

Non-Contact Flow Meter

  • Simple, low cost installation.
  • Quick and easy calibration.
  • Maintenance and abrasion free.
  • Large measuring range, from a few kg/hr to multiple t/hr.
  • Higher achievable accuracy.
  • Small size allows installation in many more applications.

Impact Weigher

  • Large robust size makes installation difficult and limits applications.
  • Calibration can be complicated.
  • Prone to maintenance and wear.
  • Can struggle with low flow rates.

If you currently have an impact weigher and would like to find out more about our non-contact flow sensor for dry bulk solids, check out the product page here, or send through an email.

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Last Updated on Tuesday, 19 February 2019 10:31