Skimmer technology - An appraisal of mop skimmer technology case study
Skimmer technology offers many alternative types such as mop, disc, drum, brush, belt, tube or weir skimmers.
A World patent was awarded to Shell international in 1967, for the use of a continuous belt of material, synthetic or otherwise, which would remove oil from the surface of water, by means of adsorption or absorption.
From that time until the formation of the company - Oil Pollution Environmental Control Ltd., (in 1980), I, together with two other former colleagues, developed a 'Rope Mop' system.
Fig 1. Example of two OPEC Mop Skimmers in operation on an airfield interceptor in the UK
This, utilized a polypropylene material to form a continuous loop of material, which would float on the surface of water, at the interface of the oil and water, to adsorb oil and not water, to remove surface oil contamination from sea water or fresh water. Other companies came and went during this time with variations, which failed for one reason or another. Others have since started up making versions of this. The technology they employ is still circa early 1970's. We - on the other hand - have continued to develop the systems, constantly improving the design as a result of experience gained in the day to day continuous operation of our Mop skimmer systems, world-wide. Also during this time and subsequent periods, various other skimming systems have evolved as listed above.
2.0 Comparison of OPEC mop skimmers and other mop skimmers:
Two important factors need to be noted:
2.1 The Mop
The yarn used by OPEC to produce the mop material has a very high degree of surface area, due to the network structure of the special polypropylene base yarn. This produces a phenomenal surface area, whether it be for use in heavy oil (viscous) or in light oils such as gas oil, diesel, Jet fuel, spindle oil, light to medium lube oil, etc....Other manufacturers use a much coarser material that does not have the surface area that the OPEC material has. Also, the construction of the mop itself is special and we incorporate a centre tape within the structure (not on the outside) which gives a much better performance and strength support. We manufacture two basic types of mop, one Black and one White. The white mop is deployed when picking up light oils and the black mop is used for picking up the heavy oils.
Fig 2. OPEC Mop Skimmer vertical deployment
There are subtle differences in the two mop types which make them so efficient in the oil recovery duty they perform. Also, because of the tremendous surface area we have, the adsorption and retention of oil is so much better than any other mop. Also note that we can produce ready looped mops at the factory, which can be threaded into the OPEC mop drive/oil extraction machines, as ready looped mop, so reducing the time spent in setting up on site, by not having to cut, splice & join mops on site. This is unique!!
2.2 The mop drive/oil extraction unit
Our range of equipment offers the unique facility of threading ready looped mop in between the drive rollers of the 'E' Series machines - the whole range and the same with the OM range. Again this gives two very important main advantages over competitor’s equipment: -
2.2.1 Health & Safety
The fact that OPEC MOP Skimmer Systems can be set up and deployed on site, without the need for the drive rollers to be rotating, offers the client a major advantage of not presenting a potential DANGER to the operatives. If an operator should accidentally trap his or her fingers in between the rollers during the threading of the mop, it can cause serious injury and we are aware of at least one major claim in Indonesia against one of our competitors. An operator had his hand crushed by a diesel driven unit, before they could shut down the engine when his hand was trapped between the drive rollers.
2.2.2 Ease and speed of equipment deployment
By having ready looped mops ready to thread through the rollers of the OPEC equipment, it obviates the need to cut, splice and join - open ended mops. It makes the job much easier and simpler for the operators, especially on industrial sites, where mop replacement may be a regular occurrence.