SunWeb: MAKING GLASS

Glass is a wonderful product. Float glass for windows (along with screens) improves homes and other buildings enormously. Think about what your home would be without glass. So this is not an essay against glass. It isn’t even an essay against using glass for solar energy collecting devices whether they are for heating hot air, hot water or making electricity.

It is important to understand the components of the energy collecting devices so we don’t designate them with false labels such as green, renewable or sustainable.

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Let’s take a look at this wonderful material.

The process to get glass is to find silica deposits, dig them up, crush them, move them to the factory, powder them in a ball mill, then put the powdered material through the production line. Here is some of the process and equipment. This is big, expensive and energy intensive equipment.

THIS IS A FOUR MINUTE FILM THAT WALKS YOU THROUGH

THE MAKING OF FLOAT GLASS FROM MINE TO FINISH PRODUCT

Float Glass Manufacturing Process .flv 4 minutes

SOME FACTS ABOUT FLOAT GLASS

Energy Use

CARBON DIOXIDE

Did you know?

Float glass plants are enormous – over 350,000 square feet under each roof.

Each plant uses $500,000 of natural gas and $85,000 of electricity every month.

Plants run 24 hours a day, 365 days a year.

Each FG plant ships 35-40 trucks of glass every day, at almost 35,000 square feet per truck.

Glass is cut in sizes as small as 16″ x 20″ to as large as 130″ x 204.”

http://www.cardinalcorp.com/products/float-glass/

“The global market for flat glass in 2010 was approximately 52 million tons. (value of around 22 billion euros at the primary level and about 55 billion Euros at the level of secondary processing, therefore a total business of about 77 billion Euros). 70 % of tonnage is consumed in windows for buildings, 10 % in glazing products for automotive and 20 % in furniture and other interior applications. Europe, China and North America together account for over 70 per cent of global demand for flat glass. Europe is the most mature glass market and has the highest proportion of value-added products. Four companies; NSG Group, Saint-Gobain, Asahi and Guardian, are fully global. 52 million tons of glass for a global population of 6.8 billion habitants means that average consumption is 7.6 kg per person and per year with extreme usage being Europe with almost 20 kg per person and per year and India with about 1 kg per person and per year. The flat glass business represents 0.1% to 0.2% of the GPD [Gross Domestic Product], in average.”

“The world flat glass industry. Focus on history & economy”. Bernard Jean Savaëte http://www.glassonweb.com/articles/article/772/

SOLAR LOW IRON GLASS

“As of 2009, the solar industries demand for flat glass accounted for 0.7% of all glass produced; we projected that this increased to 1.5% in 2010.”

Global energy glass consumption in 2012 will be 1.1% of total market

Here are the possible projections for the need for solar low iron glass. Note that the most optimistic projections crosses the current flat glass capacity around 2020.

So with BUSINESS AS USUAL and solar glass only being a small percentage of total glass manufactured, the projections on the chart above mean the need for massive manufacturing development globally.

“To double the flat-glass capacity will require building 192 new float plants, each with a 1000 ton per day capacity, at an expense of 27 - 36 billion dollars (in today’s value). To increase output to ten times current capacity will require building an additional 1523 float glass plants for a capital investment of 245-327 billion dollars. i.e., almost twenty times the value of the current annual flat-glass market.”

Glass Needs for a Growing Photovoltaics Industry

http://www.clca.columbia.edu/6_Burrows_Fthenakis_SolarMaterials.pdf

BELOW ARE PICTURES OF SOME OF THE PROCESSES

INVOLVED IN MAKING FLOAT GLASS

A MINE IN ARIZONA

ANOTHER MINE

EXAMPLES OF CRUSHERS IN THE FIELD

Silica sands contain a higher proportion of silica (up to 99% SiO2) in the form of quartz and are employed for applications apart from as construction aggregates. They may be developed from each loosely consolidated sand deposits and by crushing weakly cemented sandstones. In contrast to construction sands, that are made use of for their physical properties alone, silica sands are valued for any mixture of chemical and physical properties. These contain a high silica content material inside the form of quartz and, far more importantly, low levels of deleterious impurities, particularly clay, iron oxides and refractory minerals, like chromite.

http://www.usedcrushersale.com/solutions/silica-sand-crusher-price-in-indonesia-silica-crushing-plant.html

THE BALL BEARING CRUSHER MAKE THE POWDER FOR THE NEXT STEP

http://www.mine-engineer.com/mining/ballmill.htm

http://www.hotcrusher.com/solutions/ball-mill-working-principle.html

http://sandcrusherforsale.com/wp-content/uploads/2013/12/227.jpg

Ball mill is an efficient tool for grinding many materials into fine powder. - http://www.unisbm.com/solution/stone/small-scale-ball-mill-for-quartz-crushing-258.html

THE PRODUCTION LINES ARE HUGE AND HOT

HERE ARE SOME OF THE PRODUCTION LINE HEATS

http://durashieldmarine.com/glass-manufacturin/

Each of the plant’s six batches of dry ingredients weighs 5,700 pounds, with some consisting of sand with iron it and some without it. The materials are placed in the mixer, squared and blended with both a little moisture to avoid dust issues and cullet to help the sand burn quicker. The move allows the glassmaker to avoid wasting glass, while also lowering the company’s power consumption by limiting the heat necessary to melt the sand.

As it is, the plant is good for six-figure power and seven-figure gas bills each month.

Once completely batched, the sand is transposed into a furnace that reaches 2,950 degrees Fahrenheit. The heat is so great that the temperature of the room in the warehouse that houses the furnace feels like 162 degrees. Employees working in that area are constantly told to hydrate, but usually carry several changes of clothes each day as they sweat profusely.

http://www.iqglassuk.com/news/the-truth-about-float-glass/

http://glass.fivesgroup.com/plants-engineering/flat-glass.html

http://de.wikipedia.org/wiki/Floatglas

HERE ARE SOME CHARTS OF THE HISTORY AND DEVELOPMENTS OF GLASS