“Importance of preventive furnace inspection and maintenance”. Hans-Günter Mehl MGFS Glass Factory Services S.A. de C.V. M E X I C O
Disclaimer By presenting this paper, today, I do not want to raise my finger and act as a teacher. It is well known that every factory has it’s own filosophy and experience about furnace maintenance. Nevertheless, we are a specialised company for furnace inspections, maintenance, drilling, endoscopies, thermographies, heat-up, filling etc. We see a lot of furnaces during the 365 days of a year. We have noticed that furnace maintenance is not given with the same attention as some years ago. Preventive inspections and maintenance is laking attention. Repairs are sometimes made when it is too late and this costs money.
Defi finition of f preventive maintenance/Inspection Preventive maintenance/inspection is an action which is regularly performed on a piece of equipment to lessen the likelihood of it failling. This maintenance is performed while the equipment is still working so that it does not break down unexpectedly. In terms of the complexity of this maintenance, it falls between reactive maintenance and predictive maintenance.
Imortance of endoscopy after heat-up but before filling the furnace.
Why endoscope inspection before filling the furnace? • To see if expansion joints in the furnace bottom are completely closed. • Is the furnace bottom even or have some tiles gone up. • To see the situation of the throat. • To see the situation of bottom and sidewall electrode blocks, thermocouple blocks, bubbler row, wear wall. • To evaluate the situation of corner blocks and doghouse area. Remember, you will not see these areas anymore during the whole campaign of the furnace. Do you think it is worth investing?
Importance of making a thermography right after filling the furnace. • The furnace areas not covered with insulation material are worth a special treatment. These areas are the best indicators for wear during the life of the furnace. Areas like Glass level line, joints between tank blocks, doghouse corners, electrode blocks, bubbler row and thermocouple blocks as well as the skew back line of the furnace and regenerator crowns are normally not covered by insulating material and are therefore the best indicators for wear. • If you start making thermography reports after a year, nobody will know the temperature at the beginning of the furnace life and you have no initial temperatures which could allow a correct interpretation of the following thermographies. • REMEMBER: You will never get the chance to recover initial temperatures with original thickness of the refractory anymore. These temperatures are your best wear indicator. Do you think it is worth investing?
TAZA DE FUNDICION (LADO DER) MURO DE PUERTOS (LADO DER) 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 A 327 323 294 372 297 202 337 369 274 266 251 273 392 362 292 237 395 364 304 365 381 268 208 272 300 259 231 190 B 198 405 238 399 299 274 336 409 365 240 235 365 390 403 298 392 320 348 406 372 332 361 268 336 286 328 280 203 C 199 381 347 324 274 272 363 398 396 222 275 378 375 362 245 395 368 398 445 380 391 341 338 323 279 338 286 316 D 198 399 297 238 210 278 369 393 389 226 257 390 398 389 368 375 353 373 396 397 367 409 345 309 295 297 295 352 E 196 402 337 336 299 265 353 402 363 261 245 384 336 401 395 368 404 350 398 410 363 353 257 330 281 207 276 325 224 382 303 334 276 258 352 394 357 243 253 358 378 383 320 353 368 367 390 385 367 346 283 314 288 286 274 277 PROMEDIO� BLOCK 335 295 PROMEDIO PROMEDIO GRAFICO L/DER PERFIL L/IZQ
á ° ° á ° C 01/01/2000 01:39:02 a. m. 488.6 ° 01/01/2000 01:39:02 a. m. 150.0 FLIR0114.jpg FLIR E85 78501543 FLIR0114.jpg FLIR E85 78501543
á ° ° á ° C 01/01/2000 01:45:38 a. m. 460.8 ° 01/01/2000 01:45:38 a. m. 150.0 FLIR0141.jpg FLIR E85 78501543 FLIR0141.jpg FLIR E85 78501543
Glass Contact – Melter Bottom – The last Infrared Inspection survey was done the 26-November-2018 **drawing just for reference *Temperatures in bubblers blocks and glass line above 350 ° should be atended. *Temperatures in thermocouples blocks above 850 ° should be attended. EN-FUR-03-010 – Optical Pyrometer Operation EN-FUR-03-013 – Infrared Temperature Survey – “ ” – – –
– – Temperatures in the bottom steel plate are in good range. No actions at this point. Left side "Melter floor" 200 151 151 Melter bottom 137 132 132 131 130 124 122 118 Temperature 91 68 100 0 1 2 3 4 5 6 7 8 9 10 11 12 Center “ Melter Floor" 200 157 152 150 Melter bottom 141 141 134 133 133 126 Temperature 117 150 78 72 100 50 0 1 2 3 4 5 6 7 8 9 10 11 12 Right side “ melter floor" 200 140 143 141 140 138 Melter bottom 132 130 127 130 126 Temperature 93 74 100 0 1 2 3 4 5 6 7 8 9 10 11 12 Furnace 8, Monterrey, Mexico, “ Hot Inspection Report ” Inspection date: 6-November-2018
Furnace age and inspection intervals • Furnace start up, up to 3 years: Visual inspections each month. At least once a year endoscopy and thermography. • 3 years up to 6 years: Visual inspection, weekly. Endoscopy and thermography, every 6 month. • 6 years up to 10 years: Visual inspection twice a week. Endoscopy and thermography every 6 month and more if needed. Start to think about test drillings in the furnace bottom. Start to buy and prepare material for overcoat and other “Hot - Repairs”.
Training of furnace personnel • Involve furnace personnel during furnace construction. • Involve furnace personnel during heat-up and filling. • Training related to refractory material. • Training of personnel by specialised and skilled construction companies. • Involve furnace personel during inspections with endoscope and/or thermographies.
Repairs! In House or Outsourcing? • Try to keep at least a crew of 2 furnace masons employed. In a glass factory there is always work for masons even if it is not at the furnace. • Smaller repairs can be made by factory personnel. • Try to have a contract with a specialised outside company for inspections and the same company for repairs. These companies should keep record of your furnaces. Make them partners not only contractors. • You do not have fix costs with a company from outside but they can be part of your furnace team as if they belong to your factory.
What refractory material to keep in stock • AZS and or Zircon tiles for overcoating (Chrome is also valid) • Fused Silica bricks, tiles and ramming mix • Zircon Mullite and Zircon Silicate bricks • Sillimanite bricks and tiles • Zircon Mullite and Zircon Silicate Raming mixes • Insulating fibres as blankets and as bulk material
Economic aspects Glass at the machine is money in the owners pocket. Any unforeseen damage to the furnace will interrupt this glass flow. Preventive maintenance is always planned and foreseen. None or only little surprises can be expected. Loss of production can be limited to an absolute minimum. Smaller repairs can be made during a planned machine shut-down or mold change. Keeping record of the furnace life by inspections is a money saver. Always evaluate the risk, even if it is a planned repair, together with the subcontracted company. Try always to have experienced personel from your factory during the repair at site.
We fixed it “Just in time” is always better than “Why did this happen” Reaction from a satisfied customer January 2019
We are prepared to be your partner for these jobs. In case of need, please feel free to contact us ANYTIME. We are there to assist you 24/7, 365 days a year. Hans Mehl General Manager M-Glass Factory Services S.A. de C.V. Mobile: +52 1 7772676666 Office: +52 7773226956 +52 7773183972 h.mehl@mglassfactoryservices.com www.mglassfactoryservices.com
Thank you for your attention
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