A flat-bottom silo stores very large powder volumes on a concrete or steel floor fitted with aeration pads or air slides that fluidise the bottom layer toward a central or side outlet. It eliminates the tall cone of hopper silos, reducing overall height and civil cost, and serves cement, fly ash, flour, and mineral powders from 200 m3 to several thousand m3.
The floor is divided into aeration sectors laid with air slide fabric or pad aerators. Low-pressure blower air is sequenced sector by sector, fluidising the powder layer above each active zone so it flows along a slight floor slope to the outlet. Sequenced aeration limits air consumption, while a reverse-jet roof filter handles displaced and fluidising air.
Challenges
Dead Stock on the Floor Perimeter
Non-aerated floor zones and corners retain a permanent powder heel that ages, absorbs moisture, and reduces usable capacity by 10 to 15 percent.
Aeration Fabric Blinding
Fine or moist powder blinds air slide fabric pores over time, reducing fluidising airflow and creating progressively larger stagnant floor areas.
Moisture Carryover from Fluidising Air
Unconditioned blower air introduces humidity that hydrates cement or cakes hygroscopic powders directly at the discharge layer.
Segregation of Mixed Particle Sizes
Central filling builds a heap where coarse particles roll outward, then sequenced floor reclaim returns them unevenly, varying product grading at discharge.
High Roof Filter Load During Reclaim
Continuous fluidising air plus conveying air during simultaneous fill and reclaim can exceed roof filter capacity, causing dust emission.
Solutions
- Full-Coverage Sectored Aeration Layout: Extending aeration sectors to the shell wall with overlapping coverage and a 3 to 5 degree floor slope reduces residual heel to below 3 percent of volume.
- Dedicated Blower with Inline Air Drying: A dedicated oil-free blower with refrigerated or desiccant drying delivers fluidising air below 40 percent RH, protecting moisture-sensitive powders.
- Scheduled Reverse Purge of Aeration Sectors: Periodic high-flow purge cycles through each idle sector clear fabric pores and restore design fluidising airflow without silo entry.
- Multi-Point or Distributor Filling: A roof-mounted distributor or multiple drop points flatten the fill heap, limiting radial size segregation across the stored bed.
- Filter Sizing for Combined Air Cases: Sizing the roof filter for simultaneous filling and full reclaim airflow, with differential pressure monitoring, keeps emissions within limits at all operating cases.
Applications
- Cement Plant Clinker-Ground Cement Storage: Multi-thousand tonne cement storage between grinding mills and packing plants with air slide reclaim.
- Fly Ash Collection and Dispatch: Power station fly ash storage receiving continuous ESP discharge and loading bulk tankers on demand.
- Flour Mill Bulk Wheat Flour Storage: High-volume flour storage with gentle sequenced reclaim ahead of bulk outloading.
- Ground Calcium Carbonate and Mineral Fillers: Storage of GCC, talc, and mineral filler powders at masterbatch, paint, and paper plants.
- Alumina and Smelter Feed Storage: Large-volume alumina storage with dense-phase reclaim feeding smelter pot lines.
Model Range and Capacity: JBM-FB Series
Basis: Flat floor with sectored aeration, working volume 85 percent of gross.
| Model | Dia (m) | Cyl. Ht (m) | Overall Ht (m) | Gross Vol (m3) | Working Vol (m3) | Capacity (t) @ 0.6 t/m3 |
|---|---|---|---|---|---|---|
| JBM-FB-225 | 6.0 | 8.0 | 8.6 | 226 | 192 | 115 |
| JBM-FB-500 | 8.0 | 10.0 | 10.6 | 503 | 427 | 256 |
| JBM-FB-940 | 10.0 | 12.0 | 12.6 | 942 | 801 | 481 |
| JBM-FB-1580 | 12.0 | 14.0 | 14.6 | 1583 | 1346 | 808 |
| JBM-FB-2460 | 14.0 | 16.0 | 16.6 | 2463 | 2094 | 1256 |