https://doi.org/10.1016/j.powtec.2018.06.011
“Although the outline of the 30 kW plant has been explained in detail elsewhere [42–44], a brief description of the pilot plant is given below, including the modifications made for the attrition test. The test rig consists of two circulating fluidized bed reactors (see Fig. 3). Both reactors have an internal diameter of 0.1 m. The carbonator is 6.3 m in height, whereas the calciner has a height of 6.1 m. There are no air distributors in the reactors to facilitate the feed of solids directly to the risers. The solids are fed in by means of two screw-feeders located at the cold air entrances to the risers. The air is blown into the facility by a fan and
the flowrates to the risers and loop-seals are independently controlled by means of mass flow controllers. The bottom 3 m of each riser is surrounded by independently controlled electrical ovens, while the rest of the primary loop is thermally insulated. Each riser is connected to a high-efficiency primary cyclone, where the solids and gas phases are separated with a efficiency of about 97–99%. There are also two secondary cyclones before the stacks to ensure that there is no significant loss of solids from the facility. Downstream of the primary cyclones, the solids fall into the loop-seals through the standpipes. The loop-seals are fluidized by air that comes through gas distributors. The solids flow into the opposite riser through diplegs, fitted with small quartz windows so that the solids circulation can be visually checked. Furthermore, in the dipleg leading to the carbonator, a by-pass is located just
below the loop-seal to allow the solids circulation flowrates (Gs) to be measured and solid samples to be extracted (see Fig. 3). The solids circulation rate is measured by diverting the solids stream to a dead volume between two valves for a certain period of time.
The test facility is equipped with 40 thermocouples, seven of which are fitted in each riser, 22 in the primary loop and four around the secondary cyclones. Twenty differential pressure taps and four zirconia oxygen probes have been installed in the carbonator and in the calciner. There are also two on-line gas analysers for measuring the concentrations of CO, CO2 and O2”
“Fig. 3. Schematics of the 30 kW pilot plant at INCAR-CSIC. Grey lines and symbols are used only for carbonation/calcination tests. 275M. Alonso et al. / Powder Technology 336 (2018) 273–281 “