Furnace equipments products

Radar Glass
Level Machine

The radar glass level is the evolution of the already proven radar glass level built by Glass Service in 2012, where Glass Service was the first in the world to develop interferometric radar technology.

The new level meter has been developed on a new radar technology including all the improvements in electronics and computational performance of recent years.

  • The new system is made with a small radar antenna size of only 130×130 mm and is easily adaptable to existing working ends or forehearths. Inserted in a mechanical support of only 265×265 mm.
  • The measurement performance is significantly improved in terms of accuracy and reliability, as well as the measurement range that covers a measurable distance from the antenna of 300-5000 mm, which is very wide.
  • High-frequency 100 Hz measurement sampling allows the level of molten glass to be monitored exactly and the signal to be filtered according to furnace control needs.
  • The reading accuracy is also very high at 0.05 mm.
  • Mounting the antenna installed on top of the WE or FH with a very small and compact structure minimizes errors due to thermal expansion of the antenna support structures.

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The antenna mount includes simple adjustment systems to adjust the positioning and orientation of the radar beam. The antenna is separated from the combustion chamber of the WE or FH by a plate of special temperature-resistant ceramic material. We recommend the use of a light blow of compressed air to keep the reading oven clean of any deposits or encrustations. The antenna is equipped with a compressed air inlet for cooling. The compressed air is managed by a small pneumatic panel supplied with the machine. No cooling water is required. The antenna is capable of operating at up to 120°C. Thanks to the compressed air cooling system, it can be installed in an environment up to approx. 160 °C.

Connection Diagram

Dimensions

Specification e Technical Characteristics

Control Panel

Characteristics

Our new Glass Level control system is conceived using a technology you’ve never seen before in the glass field: the radar. Main advantages of this technology are:

  • Non-contact measuring
  • No moving part
  • Zero maintenance demand
  • Reading precision 0.05 mm

How do you measure glass level in your production hall?

What kind of system would you choose to do the following measurement?
What are the main characteristics that you have to verify for proper measuring?

The measuring precision/repeatability of your instrument must be higher than the value that you are going to detect. The instrument precision and repeatability is done from:

1) Precision of the measuring sensor and relative measuring process
2) Precision/stability of the sensors support

For a correct measure the precision of the support must be at least 10 times higher than the measure precision/repeatability required. In glass industry the glass level precision required is 0,1 mm. It means the sensor support precision/stability must be at least 0,01 mm.
Which are the parameter that influence the correct measure precision in glass furnaces? The main are:

  • Environment temperature, and furnace radiation due mechanical support deformation
  • Water temperature and water pressure for water cooled due probe deformation

Environment temperature, and furnace radiation in optical measure system

The optical measure system based on the light emitter and the light receiver are installed on a metallic support.

Because the long distance between emitter and receiver a few deformations of the support have a high error in light beam receiver position.

e.g.

For emitter-receiver distance of 3000 mm inclined an angle of 15 Deg from horizontal plane, a supporting deformation of 0,01 deg have a variation of 0,5 mm.

Environment temperature and furnace radiation in standard probe type with platinum tip

In this model the installation could be with water cooled probe or ceramic probe. In booth case the thermal deformation of the machine and his support have two main direction:

  • Linear deformation 1 in picture
  • Bending deformation 2 in picture

This value are not negligible.

e.g.
a supporting column in carbon steel + the machine body with a total length of 1500 mm have a thermal extension with 10 °C variation of 0,18 mm, more than the instrument precision to measure.

Including the bending of supporting probe (2 in picture) this value is quite bigger than the measure precision required. For the water cooled machine the thermal deformation of the probe (2 in picture) change also with the water-cooled temperature and the water pressure.

For the water cooled machine the thermal deformation of the probe (2 in picture) change also with the water-cooled temperature and the water pressure.

Who’s controlling
the controller?

You should always remember that your actual glass level is controlled by your furnace level control so if it’s introducing an error on his own you are not detecting it because the batch charger will follow exactly its signal THUS meaning that you may are reading a continuous signal which is only a continuously wrong signal with an oscillating glass level.

The antennas have small dimensions and compact design, thermal deformation is negligible.
The radar antennas doesn’t use water cooling.

How much is important a stable
glass level for furnace operation?

It’s clear enough that a very stable furnace level could be achieved only when the glass level control it’s very precise AND It’s coupled to a well dimensioned speed controlled batch charger: without this necessary condition nothing of what is following would be true. But in that case a stable glass level in your melting process determines:

  • Stable charging process = stable quantity of cold materials introduced in the basin = stable melting conditions = gas savings
  • Stable glass flow and more homogenous (through time) temperature in the distributor and feeders = gas savings
  • Stable conditioning conditions = less variation in gob weight = increased production efficiency
  • More scientific and accurate approach to furnace conduction it means less need of changings or adjustments in furnace control (i.e.: between day and night shifts settings).

Which is the overall performance increase due to a very stable glass level?

It is not easy to determine how much a very stable glass level could help increase your production efficiency but in such a competitive scenery like the one you’re acting on nowadays even a 0.001% efficiency increase would be able to grant you, on a standard 100 Tons per day furnace, an yearly advantage of more than 36 tons against your competitors.

On a provisional (minimum) equipment life time of 6 years how worth is the investment to have back more than 215 Tons of glass produced? (…and this values increases to 430 Tons for a 200 Tons per day melting furnace…). In this page we will follow with a resuming table that gives you and in-depth analysis and confrontation on 3 different level control technologies.

Comparison of 3 different
glass level control technologies

very poor

poor

standard

good

outstanding