Inspection

Visual Inspection | Data Analysis | Pictures & Videos | Temperatures measurements | Emissions measurements


Visual Inspection

A visual inspection of the furnace outlines the boundary conditions not characterized by any variables e.g. the batch charging situation or other observations.

Example: Doghouse Situation

doghouse_situation

FIGURE: DOGHOUSE SITUATION

 

Data Analysis

The basis of the Audit is the analysis of all documented process variables.
These variables are either stored in the PCS – such as Temperatures or Volumes – or manually – such as batch composition or burner settings.

 

Pictures & Videos

Typically the furnace is equipped with a TV camera visualising the furnace inside, respectively combustion atmosphere, and shows the combustion, batch charging and parts of the glass melting.
The video mainly bares the efficiency status of the combustion and indicates saving potential.
In addition, the video gives indications about the refractory conditions.

Example: Camera View

camera_view

FIGURE: CAMERA VIEW (SOURCE: FLAMMATEC)

 

Endoscopy

With a periscope / endoscope – a water cooled pipe with optical lenses at the tip – the conditions of the refractory can be observed selectively at critical points and in detail (high resolution), digitally.

Conducting endoscopy inspections on interval basis bares refractory corrosion progress etc.

By default, a direct view into the furnace and a view angle of 70 ° are used.

GSEE uses the following equipment:

  • Periscopes from Zeiss, Kinoptik and Cesyco
  • Cameras from Nikon, D2 and D70

GSEE will examine the locations requested by the customer.
Typically the following locations will be observed:

  • Crown – joints, rat holes and condensate presence
  • Superstructure – corrosion, chipping, material failure, shifting of refractory blocks
  • Skew back – joint and corrosion
  • Tuck stones
  • Burner blocks
  • Port blocks

The periscope will be introduced trough existing holes in the furnace, and peep-holes in particular.

Example: Doghouse Arch Corrosion Status

doghouse_arch

FIGURE: DOGHOUSE ARCH CORROSION STATUS

 

Temperatures measurements

The knowledge of the temperatures is key to operate the furnace.
Some of the thermocouples (NiCrNr, PtRh etc.) are measuring the temperatures directly and some of them indirectly.

In case of an indirect measurement, the ‘real’ temperature have to be estimated e.g. the ‘real’ glass temperature is, of course depending on the installation depths, 80 °C higher than measured.

Never the less, some of the temperatures, necessary to best describe the process, are typically not measured e.g. the flue gas temperature at the port exit.

 

Pyrometry

Introducing optical and suction pyrometry allows to measure those temperatures which are not measured and those temperatures which are measured indirectly.

 

(Exterior) Thermography

Thermography shows the temperature distribution of certain locations and helps to identify critical positions (as described under 1.1.3.1)

Example: Heat losses, Burner

 

heat_balance_burner
FIGURE: HEAT LOSSES, BURNER

 

Emissions measurements

The glass melting furnace is, due to the high temperatures involved, the key originator for emissions to air and NOx, SO2 and Particulates in particular.

Emission permits are decreasing constantly.
In the EU, the GLS BREF under the Directive 2010/75/EU (“GLS BREF”) and Best Available Techniques Associated Emission Levels (“BAT-AEL”) is applied.

Therefore emissions are becoming more and more vital for most of the glass manufactures.

The knowledge of the emissions after the furnace and after the air preheating device indicates the combustion efficiency and excess air volumes.

Example: O2 and NOx measurements (A = left firing, B = right firing)

 

o2_nox
FIGURE: O2 AND NOX MEASUREMENTS

Example: Correlation analysis, acc. Pearson

correlation
FIGURE: CORRELATION ANALYSIS, ACC. PEARSON