In the bulk solids processing industry, raw materials are often stored in silos before processing into finished product. Constant recording of inventory by continuously measuring levels is required for logistical or production-related reasons.
Reliable and non-contact
Free-space radar measurement has positioned itself alongside the proven ultrasonic devices as a state-of-the-art technology for this application. The device itself receives a wide variety of returned information, for example from installations or reflections from the tank wall. It must now master the task of reliably detecting the correct level signal based on this information.
The Micropilot FMR56/57 free-space radar devices with multi-echo tracking have new, innovative evaluation algorithms that evaluate each echo signal and monitor the signal curve. Due to the optimised analysis and auto-adaptive algorithms, the level signal is recorded even if it is below the fixed target suppression line. This ensures that reliable and precise measurement results are always returned even in situations where many objects are installed in the silo.
Micropilot is available in seven different versions, two of which are for bulk solids. The Micropilot FMR56 is the cost-effective basic device for a measuring range up to 30 metres, whilst the Micropilot FMR57 was developed for demanding applications in powder and granular bulk materials and can be used in measuring ranges up to 70 metres.
Antenna in the chamber
The various fractions of additives are generally stored in chambers of a cement silo. The grain size of these additives ranges from just over 0 to 16 mm. Based on the silo construction, the chambers are conical and the walls have strong reinforcing ribs in some cases. In this application, the Micropilot FMR56 equipped with a DN100 horn antenna is recommended as it focuses the microwave signal at 8° to minimise interference signals. In some chambers, the mounting location was directly next to the filling. The new measurement method, compared to ultrasonic, has the benefit of being insensitive to the noise of falling material in a nearly empty silo.
Using Micropilot’s multi-echo tracking function, the technology can clearly distinguish between interference signals and the current level in the chambers. The Micropilot always provides reliable measuring values, even under tough operating conditions and in silos with awkward geometric proportions.
FMR57 with alignment device
Often continuous measurement during filling in a cement silo is required. For example, if the silo is made of concrete, has a height of 26 m with a diameter of 8 m and uses the conventional filling method, i.e. from above via an aeration conveyor. In this cement silo, the Micropilot FMR57 free-space radar can be used with the alignment device. With this device, the Micropilot can be tilted vertically to align itself optimally to the filling cone and discharge funnel.
The analysis with multi-echo tracking provides reliable measuring values even under difficult conditions. The connection for purge air is available in the FMR57 device and can be activated when there is strong build-up on the antenna.
Reliability trumps all
The Micropilot FMR56 and FRM57 used in these applications offer a high degree of measurement reliability for level measurement in silos. They do so even under challenging operating conditions that were previously difficult to solve.
For more information contact Jan Gerritsen, Endress+Hauser, +27 (0)11 262 8000, [email protected], www.za.endress.com
| Tel: | +27 11 262 8000 |
| Email: | [email protected] |
| www: | www.endress.com |
| Articles: | More information and articles about Endress+Hauser South Africa |
© Technews Publishing (Pty) Ltd | All Rights Reserved
printer friendly version