Context
One of our customers asked us to carry out crushing tests on moisture absorbing pebbles.
These pebbles are made from compacted calcium chloride powder. Some of the pebbles may have compaction defects. These are therefore crushed and returned to the production line. They are recompacted.
The tests are used to determine if our demonstration lump breaker can crush the product samples supplied by our customer. This also helps to determine which type of lump breaker would be most suitable for crushing the pebble.
We have two bags of pebbles to carry out the tests. The first bag contains four pebbles that are rather crumbly, slightly broken, and with compaction defects. The second bag contains a single pebble of a quality close to the final product manufactured by our customer.
Test lump breaker
The demonstration lump breaker has an inlet section of 375x375mm and is manufactured from 304L stainless steel. This device has a one-piece double shaft design with a gear drive.
It is undersized compared to a newly designed lump breaker. The aim is to see if a standard crusher from our current production can meet our customer’s requirements.
Finally, the demonstration lump breaker doesn’t have a calibration grid. It has a bar grid. The purpose of the tests is not to verify that the output particle size of the product is that required by the customer, but to verify that the performance of the machine is adequate.
Tests
The tests are carried out under normal temperature conditions. The lump breaker is powered at 230-400V-50Hz without speed variation.
The 4 most friable pebbles are the first to pass the test phases. There are no blockage problems, and the lump breaker performance is good. The crushing time for these pebbles is estimated to be around 3 seconds.
The pebble closest in quality to the final product is the last to pass the crushing test. It is much more compact on the surface than the previous pebbles. There is no difficulty in crushing the product. The crushing time is still 3 seconds.
Testing shows that:
- Our demonstration lump breaker has sufficient power to crush the product.
- A single pebble can easily be crushed in 3 seconds. From experience, we can say that it is perfectly possible to crush a dozen pebbles at the same time. However, the crushing time would be different.
- We tested a lump breaker of an older design and lower power than our current range. A standard 375×375 lump breaker with a 2.2 kW motor is therefore very suitable in this case.
The initial tests are conclusive and new tests are planned to validate the customer’s request for a 4mm output granulometry and the simultaneous crushing of several pebbles.