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Mobil France Selects Silverson’s Innovative Disintegrator/Dissolver System For New Luboil Processing Plant
East Longmeadow, MA -- Mobil Oil France recently installed a Silverson D2500 Disintegrator/Dissolver system to meet
the increased demand for lubrication oil products. Not only has the system tripled the output of the site near Le Havre,
France, but the increased efficiency and the flexibility has led to considerable reductions in running costs.
In modern luboil formulations the base oil serves merely to conduct heat away to the cooling system and acts as a carrier
for a wide range of additives such as antifoaming agents, antioxidants, detergents, rust inhibitors, and dispersants which
can make up 30% of the formulation. With single grade luboils the viscosity of the oil drops at high operating temperatures,
resulting in a poor hydrodynamic film. Heavier base oil is used to overcome this, but problems arise with cold starting and
pumping at low temperatures. Multigrade oils were developed to achieve the optimum viscosity across the full range of
operating temperatures. The problems of temperature/viscosity instability are solved by the addition of polymers known as
Viscosity Index (VI) Improvers. These prevent the drop in viscosity of oil at higher temperatures, allowing lower viscosity
base oil to be used. VI improvers make up around 2% of the content of a typical multigrade luboil, and considerably increase
the raw material costs and processing times required to produce each batch.
At Mobil Oil France, dispersion and solubilization of viscosity index improver polymer into base oil was originally carried
out using a Silverson KDD high shear Batch mixer in a 10-ton vessel. Mobil Oil bought their polymer in pre-crumbed form, which
solved the problems associated with the crumbing process, but this increased costs and led to logistical problems such as storage.
In a typical production cycle, the vessel would be charged with the required amount of base oil, which was then heated to
120-140C. Pre-crumbed polymer was then gradually added to the oil and dispersed and solubilized by the Batch mixer’s
twin-headed Duplex rotor/stator assembly. Two batches per day could be produced in this manner.
Faced with a need for increased capacity, Mobil Oil contacted Silverson. Initially, the purchase of an additional Duplex
Batch mixer for use in conjunction with a Silverson In-Line mixer was discussed. However, the scale of production demanded
equipment capable of processing extremely large batches, and the Disintegrator 2500 was recommended by Silverson as an alternative
to the Duplex Batch mixers.
The Disintegrator 2500 is a complete system specifically designed for luboil production, consisting of processing vessel,
Bottom Entry mixer and In-Line mixer, all specially built to suit individual customer requirements. Working closely with Mobil,
Silverson designed, built, and commissioned a system to meet their individual needs.
The primary advantage of the Silverson D2500 is that bales of polymer of any shape and size can be added directly to the vessel.
This eliminates the need for pre-crumbing; a labor and maintenance intensive process which is increasingly undesirable based
on the level of dust emissions as well as health and safety regulations. Once the polymer has been added to the vessel, the
vortex created by the powerful Bottom Entry mixer draws the bales down into the coarse-tooth disintegrating head which literally
rips the polymer to pieces. These are then further reduced in the interior of the workhead before being forced out through
the stator back into the surrounding liquid. Once the solids have been sufficiently reduced the In-Line mixer is started.
Product is drawn from the vessel and processed in the In-Line mixer’s rotor/stator workhead before being returned to the vessel
by the mixer’s self-pumping action. The fine particle size obtained, combined with the vigorous in-tank agitation created by
the Bottom Entry mixer disperses and solubilizes the polymer in a fraction of the time taken by traditional methods, leaving
no undissolved material on the vessel walls.
The system is located inside Mobil’s highly automated production facility at Notre Dame de Gravenchon. Three 20-ton batches
can be produced in two shifts – three times the previous output. In addition to the reduced cost of polymer in bale form rather
than pre-crumbed, storage and handling are easier, reducing manpower and maintenance requirements. The system can, in fact,
process polymer in any form: bale, precrumbed, pellets or new generation “cold flow” material. Even polywrapped bales can be
loaded straight into the vessel without removal of the wrapper, eliminating the need for cutting and excess waste. Dust emissions
are greatly reduced, and the entire operation is now a cleaner, more efficient process.
The Silverson D2500 allows polymer to be solubilized at lower temperatures, reducing the risk of oxidation and discoloration
of oil when processed for long periods at high temperatures. This also means that polymer can be added to the base oil during
the heating process, or even during charging of base oil into the vessel, shortening processing times even further.
Click here to view more information about the Silverson
Duplex Disintegrator/Dissolver.
To speak with a Silverson representative or arrange for a free trial, please contact us.
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