PART 2 The Case for Superior Blast Wheel / Turbine Efficiency
Less energy consumption up to 25% cost-savings and compliance to environmental policy.
Depending on the size and type of shot blast process i.e. type of machine – Table, Hanger, Barrel, or Through Conveyor, the cost of running per hour adds up.
A simple small table or hanger machine may pull between 11 amps to 60 amps / blast wheel. A single blast wheel will require 5.5kW to say 30Kw. Using a nominal 10p / kW hour, costs range from 55p to £3.00/ blast hour x 2,200 hours / annum equates to between £1,210 and £6,600.
In many cases small hanger machines typically have 2 x 11Kw electric motors fitted. This represents a power of 22Kw and at 10p /Kw hour the running cost is in the range of £2.20 / blast hour x 2,200 hours / annum = £4,840. An achievement of 50% additional productivity could achieve a saving of £1,613 / annum on blast wheel power alone.
In addition, the total machine could be switched off for a third of the time and the loading labour switched to another job, saving a further 13.3Kw / hour on 733 hours/ annum at 10p / kW hour equal to £974 plus one operator labour cost at your production site. Typically totalling £1,613 plus £974 plus estimated labour at £15 / hour = £10,995 adds to the sum of £13,582 in savings!
Roller conveyor shot blast machines employ four or more of these blast wheels and the control and utilisation can become key cost factors on which savings can be achieved.
An alternative consideration to this is the fact that a smaller powered motor can achieve the same process results when connected to the more efficient blast wheel.
Maintenance has a cost, and can be saved upon too
Maintenance labour, Access and PPE provision, planning, purchasing procedures, downtime (loss of production) are often carried out in premium hours, outside normal production. Alternatively, maintenance operations can also substantially increase the cost of work carried out during normal hours due to the loss of normal production.
Placing a cost to this is subjective, according to the business type, process and maintenance plan implemented.
Typically, a set of standard cast vanes or blades using S230 / GL steel shot will last anything up to 2,000 blast hours according to the application. On the other hand, if a hard GH steel grit is employed to provide a keyed surface, as little as 90 to 100 blast hours can be expected from a standard cast vane or blade.
Accordingly then, the superior turbine blades will be expected to last at least double and up to 20 times more blast hours, depending on your application.
Regular “Blast Pattern” checks can be deferred and spaced out further because the Impellor and Control Cage are engineered in superior materials and to higher standards. Slower wear or life longevity of these components means that your blast pattern endures much, much longer, minimising a reluctant and time-consuming maintenance process.
Note! In a sand casting foundry, most of the wear is by residual sand left in the abrasive after being cleaned. (It is a well-established fact that 2% of sand and contaminants that remain in the abrasive for recycling will double the use of standard wear parts consumed). An answer to this problem can be provided too.
By changing to a more modern designed blast wheel, constructed in more wear-resistant materials, we can save both maintenance labour and wear parts replacement costs.
For more information on Superior Blast wheels and Retrofit opportunities visit www.rosler.com
Post written by
Shot Blasting Technical Manager