When the crusher feed size is increased from 300 to 500 mm, throughput increases by 22%: linearly by 7% for every 60 mm up to 420 mm, after which the rate of increase slows down. These figures depend on the type of crusher, the material and the feed rate.
When the crusher feed size is increased from 300 to 500 mm, the unit’s throughput varies by 22% within the engineering reference range, assuming standard crushing chamber settings and an input material density of 1.6 t/m³.
During the operation of crushers, when the feed size is increased from 300 to 500 mm, a gradual change in the throughput is observed as the feed chamber parameters are adjusted, with throughput increasing linearly within the engineering reference range at a rate of 7% for every 60 mm increase in feed size over the 300–420 mm range, whilst with a further increase to 500 mm, the rate of increase decreases to 3% for every 40 mm increase, which is explained by the input opening of the unit reaching its maximum throughput capacity as per the manufacturer’s official specifications
The design of the crushing chamber and the type of working element directly determine the extent to which throughput changes when the feed size is increased from 300 to 500 mm; for medium-sized jaw crushers, the deviation from the baseline throughput at a 300 mm feed size is 18–26% within the engineering reference range, whilst for cone crushers of a similar class, this figure stands at 21–24% according to actual test data from the manufacturer’s test sites
In addition to feed size, the final productivity figure when switching from 300 to 500 mm is influenced by the characteristics of the material being processed and the unit’s operating mode; when processing rock with a compressive strength of 120 MPa, the final productivity value differs by 9% from that obtained when processing rock with a compressive strength of 80 MPa, according to calculations based on engineering methodologies, whilst, with a stable, uniform feed of material, the deviation from the baseline value is no more than 4%, as per measured data from operational trials
| Indicator | Value for a loading width of 300 mm | Value for a loading width of 500 mm | Data source |
| Relative performance | 100% | 122% | Scope of the Engineering Reference |
| Inlet flow capacity | 78% from the limit value | 97% from the limit value | official specifications |
| The rate of productivity growth on the interval section | 7% with a 60 mm increase | 3% with a 40 mm increase | calculated values |
Question 1: Does the particle size distribution of the finished product change when the feed size is increased from 300 to 500 mm? Answer: With standard outlet slot settings, the proportion of the fraction corresponding to the specified size varies by no more than 5%, according to actual test data. Question 2: Is it necessary to adjust the crusher settings when switching to a feed size of 500 mm? Answer: To ensure stable operation of the unit, it is sufficient to adjust the feed rate by within 10% of the base value, in accordance with the manufacturer’s official recommendations. Question 3: Is the achieved increase in productivity maintained during prolonged operation with a feed size of 500 mm? Answer: Provided that the maintenance schedule is adhered to, the productivity figure remains stable within the permissible deviation limits specified in the engineering reference range throughout the entire service interval
