Workboat operators could benefit from CCV
A Super Impactor. Increasingly, higher efficiency CCV systems are being fitted at the point of manufacture to ensure that the engine meets the current MARPOL MPEC 58/23 regulations.
The latest wave of crankcase ventilation separation system (CCV) filtration technology will simplify the task of meeting emission standards, says Adam Pearce of Parker Hannifin’s Racor Filter Division Europe.
The On-Road EPA and Euro 5 and 6 standards were drawn up to reduce a wide ranging list of emission types (soot particles, NOx, un-burnt fuel or oil and CO2). In the case of shipping, MARPOL regulations offer a similar set of limits.
Part of meeting legislation means addressing the emissions released by the crankcase breather. Engineers have for some time found it necessary to intercept the harmful crankcase contamination that is caused when combustion gases under high pressure are blown past the piston rings into the crankcase and divert it into the air intake system, protecting both crew and engine components.
Crankcase ventilation separation systems (CCV) have proved to be highly effective and are widely used. For example, John Deere, CAT and Volvo marine engines use closed crankcase CCV systems that eliminate undesirable oil and gases from the engine room and keep the bilge clean.
Owing to this popularity, CCV is continually being refined. For some years CCV systems have seen blow-by processed through high efficiency filters and returned to the combustion cycle via the turbo charger, creating a closed loop that prevents environmentally harmful hydrocarbons from escaping to the atmosphere. Some of the newest systems just coming onto the market utilise a small amount (<1%) of turbo air as a power source to improve performance, other powered CCV systems include centrifuge products and rotating filters, and can also offer improved results over stand-alone unpowered filtration based CCV devices, the best of which include a high performance regulator allowing crank pressure to be maintained independently, no matter how clean or dirty the engine air inlet filter is. This keeps crankcase pressures consistent at all engine speeds and loads, rather than having varying levels of regulation as found with downstream vacuum limiters.
The retrofitting of Closed Crankcase Ventilation (CCV) filtration and separation systems is already wide spread within the maritime industry, as it allows for better engine room house-keeping and a cleaner healthier atmosphere on board ship by ensuring that all engine emissions come only from the final exhaust system. Some older vessels are also fitted with inadequate closed crankcase breather systems, which allow excessive amounts of oil carryover to hit the turbo and after-cooler systems, which can reduce engine efficiency by as much as 10% and ultimately lead to a breakdown.
Increasingly, higher efficiency CCV systems are being fitted at the point of engine manufacture to ensure that the engine meets the current MARPOL MPEC 58/23 regulations (Tier II of which came into force on 1st January 2011), whilst maintaining long term performance and reliability. As such the CCVs are becoming an integral part of base engine design. This may bring peace of mind when purchasing new vessels, however, operators of existing craft, such as workboats, pilot launches and wind farm support vessels, or even larger tugs and dredgers, may need to consider upgrading their CCV filtration and separation systems to ensure continued performance and reliability.
Thankfully, the market leading developers of CCV technology are developing systems that are easy to live with, require little or no maintenance, are compact and extremely efficient. Many of these systems are also future-proof, meeting not only current standards but also capable of meeting future legislation.
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