Birds Eye Chilies

We don’t recommend using a desired Universal Cutting Mill PULVERISETTE 19 for comminution. With this cutting mill principle, the sample remains relatively long inside the grinding chamber. With sugars / starch / moisture or fat content of seeds, we expect a much faster clogging of sieve cassette perforations, compared to a Variable Speed Rotor Mill PULVERISETTE 14. Also, an advantage would be the pricing and table top size of a Variable Speed Rotor Mill PULVERISETTE 14.

In general, we recommend only comminuting a sample as fine as required, not as fine as possible. Operating like this will increase the handling of a sample and maximizes the throughput of sample.

Typically, a sample would be ground to d50 < 0.375 mm, when a sieve ring with 0.75 mm perforated sieve ring would be used. Because of this, we performed our first trial with a 0,75 mm sieve ring. We picked a smaller amount of ~ 100 grams to perform this first test. To comminute higher amounts of sample, we used a Small Volume Cyclone (passive, without vacuuming). For a grinding of one kilogram of sample, we recommend using a high-performance cyclone separator with sample exhauster. With this system, up to 5-liter glasses of sample could be ground. Also small steel barrels are available for a comminutino of higher sample amounts. The sample exhauster system comes with dust category M protection.

The chilies were fed with a constant feed rate into the feeding funnel. The sound of grinding was relatively smooth and vanished almost instantly after each pod was fed. It required 45 seconds until the complete glass of sample was transferred into the mill. A small amount of sample remained inside the collecting vessel. The majority of ground sample was blown into the 500 ml collecting glass of the cyclone.

Trapezoidal perforations of the used sieve ring remained free. Also, the labyrinth disk (below the rotor) was not significantly polluted. Most likely, also the desired kilogram of sample would be grindable without a cleaning step between.

Cleaning was performed rapidly by vacuuming with a soft brush. For an intensive cleaning, also all grinding parts could be disassembled without tools and washed with warm water.

Our second trial was performed analogue result 01. Instead of a 0,75 mm perforated sieve ring, we used a sieve ring with 0,5 mm trapezoidal perforations.

The 100-gram batch was fed into the mill within 50 seconds. Also with this trial, the grinding sound was smooth and vanished almost instantly after each pod was transferred into the mill. A bit of fine sample dust seemed passed the 40 µm filter frit element of the small volume cyclone.

With this test, only a small amount of ground sample was transferred into the cyclones collecting glass. The majority of ground sample was so fine, that they stayed attached to the wall of the collecting vessel with outlet. Surly an actively used cyclone (with our sample exhauster instead of the filter frit) would transfer more sample out of the collecting vessel.

The used 0,5 mm sieve ring was not significantly clogged with sample and higher amount of sample could be ground as well.

The Premium Line version of our Variable Speed Rotor Mill PULVERISETTE 14 could be converted into a cutting mill where the sample escapes the grinding chamber relatively fast. Combined with our high-performance cyclone separator, we expect that higher sample amounts would be grindable. Typically, this type of mill achieves much finer cutting results, as shown with our Universal Cutting Mill PULVERISETTE 19 (who spins with up to 3000 rpm instead of 18000 rpm with our premium line Variable Speed Rotor Mill).

We used the cutting mill equipment and placed a sieve shell set with 0,5 mm trapezoidal perforations into the holder.

About 80 grams of chili pods were prepared and relatively fast fed into the feeding funnel. The protective screen above the funnel was removed to feed the intact pods. A safety goggle was used to protect the eyes of the operator. After only 35 seconds, the complete sample was fed and ground. Only a small amount of residue was left inside the grinding chamber. The perforations of the used sieve shell set were not clogged significantly. Only a small amount of ground sample built up in front of the static knives inside the sieve shell holder. Surely higher amount of sample could be ground this way.

Most likely a 5-liter collecting glass would be required when a complete kilogram of sample should be ground.