Collection of representative analysis samples with a static sampler at high mass flow rates in the process
The sampling with MIXER is used to collect homogeneous and representative analysis samples from process stages with high mass flow rates of dry, relatively narrowly distributed bulk solids, e.g. during the grinding of cement or anode coke. With the aid of two-stage sampling, it is possible to realise extreme division ratios that extract suitable analysis samples in the range of a few grams from product mass flow rates of over one hundred tonnes per hour for real-time laser granulometry with MYTOS. Sample collection at mass flow rates of up to 400 kg/h are realized in a single step directly with MIXER.
For on-line particle size analysis on processes with high mass flow rates, robust screws or air slide samplers are frequently used for primary sampling. They branch off a partial stream with a throughput of typically 30 kg/h to 50 kg/h from the main mass flow. The sample amount extracted in this way is still much too large for the laser diffraction method and therefore needs to be reduced further. In the bypass line, the partial stream is fed into the MIXER for secondary sampling.
The product, which is distributed across the 60 mm pipe cross-section, is randomly mixed and homogenised through a sequence of coarse bar gratings. A static probe positioned centrally in the pipe extracts from this uniformly distributed product stream a representative analysis sample of just a few grams, which is suitable for laser granulometry (for cement: approx. 2 g to 5 g). Sample collection in production lines with mass flow rates of up to 400 kg/h are realised directly with MIXER.
For adjustment of the sample amount, there are five differently sized inlet openings for the probe tip ranging from 1.5 mm to 2.5 mm. A pneumatic oscillator generates vibrations that ensure unobstructed transportation of the product and dedusting of the MIXER sampling. An integrated blow-back device keeps the entire system free of residues, enables particle-free reference measurements and prevents the risk of cross-contamination.
- Sampling system for collection of representative analysis samples
- MIXER pipe diameter of 60 mm for a maximum mass flow rate of 400 kg/h
- For dry and also cohesive powders ranging from 0.25 µm to 1,750 µm
- Suitable for product temperatures from -20°C to 80°C
- Operable at ambient temperatures from -20°C to 55°C
- Usually installed after primary sampling with screws or from air slides in processes with high mass flow rates from 20 t/h to over 500 t/h