Case Study #273
1. Headline: Internal recycling at a French glass packing
plant reduces water consumption.
2. Background: The factory Saint-Gobain Emballage in Cognac
specializes in the manufacture and packing of glass with a
production capacity of 1150 tons/day. The kilns operate
continuously and are cooled in a closed circuit (120 m3/d
of make-up water). This case study was carried out in
1992.
3. Cleaner production Principle: Internal recycling
4. Description of Cleaner Production Application:
Information about the process and wastes
On each machine a gutter drains off the glass particles in
the basement during the cutoffs. Glass and water are thus
discharged into a granulator where scraping chains remove
the glass to the recycling plant. Upper flow water carries
along glass particles as well as drops of full oils,
machine grease and soluble cutting oils. This water can
reach a temperature of 60 to 80C.
Gutters drained these waters with the rain water to the
River Charente i.e. 1500 to 3200 m3/d with the following
characteristics :
SS : 150 to 300 mg/l
BOD : 10 to 50 mg/l
COD : 50 to 150 mg/l
Hydrocarbons : 5
to 20 mg/l
pH : 7.5 to 7.8
SGE built a treatment and recirculation plant for this
machine water, rather than remaining in open circuit and
carrying out a more expensive physico-chemical treatment.
Upper flow is discontinued and the water, collected
separately from the rain water, is pumped to a settling
and oil removal tank, then recirculated towards the
machines. The sludge with glass particles is remelted with
the ground glass and the oils removed by a patented
collector.
Material / energy balance and substitution
Maxi discharge : 250 m3/d, i.e. 10 % of the recommended
value.
5. Economics:
Cost of direct investment: 4 500 000 FF (1992)
Operation and maintenance costs: About 50 000 FF/year
6. Advantages: Applying the standards in force allocated to
the factory in Cognac by their order of authorization for
exploitation. Reducing the water consumption.
7. Constraints: The glass particles sludge easily becomes
solid.
Planning an aero-cooler on the water circulation loop.
In order to avoid any disturbance in the recirculation,
the water washing the parts of the machines is treated
separately on an oil removing drum.
8. Contacts:
Agence de l'Eau Adour-Garonne
M. GARIADOR
TEL: 33 61.36.37.38
M. HARRIS
Responsible for SGE investments
TEL: 33 16.1.47.62.39.09
Saint Gobain Emballage (SGE)
Chateaubernard
16103 COGNAC - France
TEL: 33 45.82.51.99
FAX: 33 45.36.12.80
M. Maton
M. Chatenet
Office International de l'Eau
Direction de la Formation et des Etudes
rue Edouard Chamberland
87065 Limoges Cedex, France
TEL: 33 55114770
FAX: 33 55777115
9. Keywords: France, crystal and glass, packaging,
recycling, glass, ISIC 3620
10. This case study was submitted to UNEP IE in 1994 by the
French Office International de l'Eau. It has not undergone
a formal technical review.