Performance

Production of MISU Units

As any experienced earthmoving equipment operator knows, production of any earthmoving machine is dependent on a number of variable parameters. These parameters range from moisture content, job layout, and plasticity of material through to operator technique to name just a few.

MISU advocate the most suitable method to determine an accurate production estimate of a particular material of a required size through a particular model MISU unit, is to physically do an onsite timed production demonstration where practicable.

The first step is to ensure that the correct build of the screening unit specification is applied, the approved installation to the carrier machine and fine-tuning of the side rakes produces a finished product that meets the required specification.

The next step is to cycle the unit noting the average cycle time and the conservative cubic capacity of the unit.

Theoretical Calculations for MISU units

As an example, let’s assume we have a 1.2 cubic metre capacity EW140 correctly installed on a nominal 20 tonne excavator. Assuming we are happy with the finished product we can cycle the unit. Assuming the unit takes 45 seconds to cycle this is 0.75 of one minute. To be conservative we allow 1.1 cubic metres per cycle and production calculations are derived on 50-minute hours. (An average 10-minte loss is used to cover waiting time, positioning the machine and other unproductive time).

From the above we can conclude:

• 50 minutes divided by the average cycle of 45 seconds (0.75 of a minute) equals 67 cycles per (50minute) hour.
• 67 cycles multiplied by 1.1 cubic metres give a conservative average production of 73.7 cubic metres per hour.

Similarly with the above parameters, productivity for EW100 & EW180 model excavator screens would be:

EW100: @ 0.6 cubic metre capacity = 40.2 cubic metre’s per hour
EW180: @ 1.6 cubic metre conservative capacity = 107.2 cubic metre’s per hour

(The above information is provided as a theoretical guide only)

Production Estimate Guidelines

If an onsite demonstration is not possible we have prepared the following graph to assist potential customers to calculate production in a selection of common materials. This information is offered based on experience and external parameters may increase or reduce these estimates.