The employment of a high-performance fluidized bed reactor for process applications requires close cooperation between the system builder and the customer. This takes place under consideration of the specific requirements of the respective chemical process, the material properties and the required product parameters and quality grades. Several lab and pilot systems of different sizes are available at the processing pilot facility at SCHWING for the development of products and processes.
To assess the suitability of the material to be used, “cold” fluidization tests are performed, and the samples are examined in regard to their fluidization feasibility. These tests provide information about the typical fluidization parameters of the powder to be converted and the interim or end products. The tests are performed in a transparent lab cylinder equipped with a scalable gas distribution plate under ambient conditions.
The trials provide information on the behavior of the materials in a fluidized bed and permit an objective assessment of their flow properties. The fluidization parameters ascertained, in addition to the process parameters defined by the customer, are used to generate a test program for pilot facility trials.
Scale-up and pilot tests
Based on the results of the fluidization tests the experts from SCHWING decide together with the customer which reactor size is practical for further trials. Several pilot systems with sizes from two to 120 liters are available for test purposes in the temperature range up to 1100 °C and for reaction pressures up to 15 bar. The data ascertained in the lab reactor are normally performed as pilot facility tests in the so-called dip reactor (2 to 8 liters) on batch mode to check the feasibility, product quality and optimization potential.
The tests are performed under process conditions. Samples can be taken during the tests, different gases can be supplied and their quantity determined. All data about the process flow, for example, the fluid-gas flow and its composition, the process temperatures (up to 1100 °C) as well as heating, holding and cooling times of the individual process steps are recorded and documented precisely in a report.
The dip reactor’s distinguished feature is the immersion of the fluidized bed reactor into another fluidized bed container. This allows very quick heating of the reactor, which can, however, also be cooled down quickly in a second fluidized bed container, which reduces the waiting times between the tests significantly.
Batch fluidized bed reactors with a capacity from 6 to 120 liters are available for scale-up tests or contract production up to a material quantity of one ton.