Quarrying Engine emissions
Malcolm Kent, senior technical consultant at the Construction Equipment Association, explains what the new regulations mean for you
2012 promises to be a busy year in the plant sector, as the latest engine emissions control regulations loom. We are currently in the transition phase between two stages of engine emissions control for all non-road mobile machinery (NRMM) in Europe.
NRMM covers just about every kind of machine with an engine in it except for on-highway vehicles, including machines which are mobile but not self-propelled such as compressors and generator sets.
Timeframe for NRMM implementation
For diesel engines over 130kW (177PS) emissions, Stage IIIB started at the end of 2010, and for engines between 56 and 130kW (76 and 177PS) it started at the end of 2011. For engines between 37 and 56kW (50 and 76PS) Stage IIIB cuts in at the end of 2012 but there is currently no Stage IIIB planned for engines below 37kW. However, machine suppliers are allowed some flexibility in the dates. Firstly, under the ‘sell-off’ scheme, engines built before the new stage comes into effect can be used in machines built and sold later. This is to allow for the normal lead times of stockholding and manufacturing. Secondly, there is a ‘flexibility scheme’ written into the law which allows machine manufacturers to build a limited number of machines which have engines from the previous stage several years into the ‘new’ stage. This is to allow them to smooth out their product development work and also to allow smaller manufacturers some additional leeway. The upshot of all this is that not all machines from day one of 2012 will have Stage IIIB compliant engines in them, even if their power is over 56kW. This could be important when we look at the London Low Emission Zone below.
So what kind of changes are you likely to see on machines? Well, each engine manufacturer has developed a solution to meet the emission limits of Stage IIIB and they are not all the same. There are pros and cons to each of the solutions on the market but they all meet the regulations. The solutions on the market mainly consist of a combination of some of three technologies, along with electronic engine control:
• Selective Catalytic Reduction (SCR). This means having a urea tank on the machine which needs regular refilling. SCR reduces the NOx (nitrous oxide) emissions.
• Diesel Particulate Filter (DPF). These have a filter and a catalyser at the end of the exhaust
62 Solids & Bulk Handling • May 2012 Cat Stage 3B engine
www.solidsandbulk.co.uk
system, usually where the muffler would be. They need to go through regeneration cycles (either manually or automatically) to burn off the trapped particles. A DPF reduces the emission of particulates – small particles of dirt.
• Exhaust Gas Recirculation (EGR). This is a system that bleeds off a portion of the exhaust gasses from the engine and feeds it back in to the cylinders with the incoming air. EGR also reduces NOx emissions.
Although only DPFs obviously reduce particulate emissions, the reduction in NOx emissions from the other two can allow other tweaks to be made to engine settings to get the particulate emissions down to the right levels, so not all Stage IIIB engines need a DPF.
There are knock-on effects of some of this, too, beyond the engine itself, such as the need for bigger radiators to take away more heat, and of course, the need to top up the urea tank when the machine needs it.
And the bad news? Well, new technology doesn’t come cheap and engine manufacturers will need to sell at a cost which will eventually recover the huge investment they have made towards giving us all cleaner air – although emissions from NRMM have been shown to make only a very small contribution to overall air quality problems.
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68