Content measurement in Silos and storage hoppers remastered

UWT has taken the old-time rock ‘n roll method of content measurement in Silos and storage hoppers and remastered it to perfection, enabling seamless integration with our modern-day control systems and PLC’s. The UWT NivoBob continuous level measurement system offers a high-tech Approach version of a simple and very reliable measurement principal:

The basic working principle is as follows:

• Sensor weight drives down on a measuring rope/ tape.
• The rope/ tape length is electronically measured by the rotation of the internal rope/ tape roller
• Material contact stops movement and the rope/ tape relieve for a short time
• Motor changes the direction of rotation
• Sensor weight is driven back to the upper stop position
• The distance is measured, and signal outputs are activated (pulse/ relays/ 4-20mA/ Modbus/ Profibus)

APPLICATION EXAMPLE:

THE CHALLENGE:  Content measurement for silos – The level measurement should be carried out in storage silos for gypsum powder. The finished product is conveyed pneumatically into the storage silo after production. The overall production planning is difficult if the fill level monitoring of the storage silos is missing. The operator previously had to climb onto the silo roof and carry out a manual level measurement with a rope and a weight. This yielded inaccurate results and caused huge losses in stock management and control. The task was to automate the level measurement and to avoid manual measurements.

THE SOLUTION:  The UWT lot system Nivobob 3200 in the tape version fulfills these extreme requirements. The integrated tape cleaner prevents contamination of the band interior. The Nivobob 3200, thereby, provides a reliable measurement that can be totally trusted. Neither very dusty nor clumpy conditions adversely affect the UWT Lot system. The electromechanical sensor NB3200 is developed for dusty applications and for high process temperatures and is the best solution in this gypsum storage.

THE PRODUCT:  NB 3200 Tape Version

FEATURES OF THE NB 3000 SERIES:

• No adjustment to media necessary
• Discontinuous level measurement for nearly all kinds of bulk solids
• Solids in liquid interface measurement
• Insensitive to dust, dielectric constant, conductivity, humidity, caking, changing product characteristics
• Easy installation & maintenance-free
• Corrosion-resistant due to high-quality coatings and stainless steel
• Very precise results covering large measuring ranges up to 50 m under difficult conditions
• Separated chambers (mechanic/electronic)
• Integrated tape cleaner for difficult bulk materials (powder, build-up) to save the mechanic chamber
• Modus and Profibus Interface with 4-20mA and relay inputs and outputs.
• Process temperature up to + 250 C possible
• Process overpressure -0,5… + 1,7 bar
• Suitable for hazardous locations (dust explosion ATEX II 1/2D)
• Process connection thread R 1 ½ “, flange DN100 PN16 or others
• Various measuring weights available depending on application conditions
• Measuring interval 30 minutes 24 H a day – motor lifetime: 28.5 years

When it comes to ignoring the cone after filling or the upside-down pyramid after draining the silo/ bunker, and achieving reliable, accurate measurement results, Physics and experience play a role. To get to this, the NivoBob must be mounted 1/3rd from the radius of the silo to accurately cancel out the cone effect you will get.