Glass level measurement to improve the glass production

BERTHOLD Technologies: Industrial glass melt furnaces are used in glass production to melt raw ingredients (batch) into a molten glass at temperatures exceeding 1200°C. Level control just after the outlet of the melt furnace is one of the main process control challenges to facilitate efficient and high-quality glass production. Due to the harsh conditions, non-contacting measurement methods are mandatory.

Radiometric based level measurements offer best in class reliability and safety for the glass industry to aid in streamlining glass production and producing consistent quality glass while minimizing costs and maximizing throughput.

Measuring glass level at the feeder channel

Reliable glass level measurement and control at the beginning of the feeder channel is necessary for a streamlined and efficient glass production as well as consistent glass quality.

Online glass level measurements offer non-contacting, continuous glass level readings with an increase in accuracy, reliability, and a reduced feedback loop that allows for improved response time. With this, process upsets such as low or high batch bin level or glass pull runaway can be assessed in seconds rather than in hours. Such an online measurement can be performed with a radiometric based level measurement. The principle of this measurement is based on the attentuation of radiation when penetrating matter.

Characteristics

Non-contacting measurement
Not exposed to the harsh process conditions
Removement of only some of the refractory bricks is necessary
Simple and precise adjustment of the calibration position via slider

Customer benefits

Online level measurement
Good repeatability of the measurements
Resistant to dust and gas

Technical features

Measuring range:
typically 0...5 mm to 0...30 mm
Accuracy:
+/- 0.5 % of the measuring range
Achivable resolution 0.05 mm (0.002 in)

Reliable glass level measurement arrangement and control

Due to the absorption of gamma energy it is common with nuclear glass level measurements to remove some, but not all of the sidewall refractory bricks on either side of the width of the feeder channel furnace. Using the laws of physics and statistics, as well as sophisticated software, the success of any nuclear-based measurement is almost granted. However, correct and exact application information is imperative for the design of an accurate and reproducible measurement.

Alignment and calibration

Typically, calibration points are taken at the maximum and minimum glass level operating condition. Calibration points are taken with glass flow remaining steady at the designed furnace glass level. A precise method to raise and lower the source shield and detector in lockstep to each calibration point can be achieved using a detector/shield mount that incorporates precision adjustable linear slide rails.

Glass melt furnaces require high resolution and repeatable level control of the feeder channel to ensure stable charging, flow, and glass pull. Accurate alignment and calibration of any glass level measurement system is critical to the performance of the measurement.