1. Overview: why the mill needs multiple pump technologies
The sugar-ethanol process spans fluids with radically different properties. Cane juice is light and watery. Molasses is dense and sticky. Thermal oil operates above 300°C. Vinasse is corrosive and abrasive. No single pump technology covers all these requirements efficiently.
FB Bombas serves the sugar-ethanol sector with multiple technologies: gear for viscous fluids, centrifugal for light fluids and FBOT for thermal. This allows the mill to standardize its pump supplier, with spare parts from a single factory and unified technical support.
2. Molasses and final honey — FBE series (gear)
Molasses and final honey are the most viscous fluids in the mill. Viscosity can exceed 50,000 SSU depending on temperature and solids content. The FBE external gear pump is the correct technology for this application.
- Typical viscosity: 10,000 to 50,000 SSU (depending on temperature and Brix)
- Recommended speed: 300 to 850 rpm (FBE manual Table 2 — range 2,500 to 50,000 SSU)
- Transmission: pulley or gearbox (direct drive only up to 2,500 SSU)
- Typical models: FBE 1.1/2" to 6" (per required flow)
- Material: cast iron ASTM A48 CL30 (standard) or stainless steel for food contact
3. Cane juice, vinasse and process water — FBCN series (centrifugal)
Cane juice, vinasse and imbibition water are low-viscosity fluids that require high-flow, energy-efficient pumps. The FBCN series meets these demands with back-pull-out construction and ASME B73.1 compliance.
- Cane juice: FBCN in 316 stainless steel for hygiene. Flow per mill capacity
- Vinasse: FBCN in 316L stainless steel — highly corrosive fluid (pH 3.5 to 5.0) with suspended solids. S3 (flushing) seal type recommended
- Imbibition and wash water: FBCN in cast iron (standard). Flow up to 2,200 m³/h in larger models
- Maintenance: back-pull-out design allows removing the rotating assembly without disconnecting piping — ideal for inter-harvest shutdowns
4. Thermal oil in evaporators and vacuum pans — FBOT series
Multiple-effect evaporators and vacuum pans require precise and continuous heating. Thermal oil is the most common heating fluid in these stages. The FBOT series is the FB Bombas centrifugal pump designed specifically for this application.
- Operating temperature: typically 280°C to 320°C (FBOT maximum: 350°C)
- Dual sealing: graphite packing (first stage) + mechanical seal submerged in oil (second stage)
- Maximum pressure: ~12 bar at 300°C (pressure × temperature curve from FBOT manual)
- Back-pull-out construction — same maintenance advantage as FBCN
5. Fire protection in the mill
Sugar-ethanol mills operate with bagasse (solid fuel), ethanol (flammable) and high temperatures in boilers and distilleries. Fire protection is mandatory. FB Bombas supplies complete systems per NFPA 20 and NBR 16704.
- Main pump (electric) + standby pump (diesel) + jockey pump (pressurization)
- Complete pre-assembled skid with automatic control panel
- NFPA 20 (international) and NBR 16704 (ABNT) compliance
6. Why juice and vinasse punish ordinary pumps
Sugarcane juice is not sweetened water — it carries fibrous bagasse fines and sand that comes from the field with the cane. This abrasive fraction works like continuous sandpaper on impeller and volute, and is why mills specify wear-oriented clearances and materials, and overhaul internals at the end of each season.
Vinasse stacks aggressions: it leaves distillation hot (typically 85 to 95 °C) and with acidic pH, in the 3.5 to 5 range — a combination that accelerates corrosion in plain cast iron and degrades sealing elastomers not specified for the service.
At the other end of the process, molasses punishes the opposite mistake: pumping it fast. Above the proper speed, the viscous fluid does not fill the tooth chambers in time, the pump cavitates from incomplete filling and the real flow collapses. That is why the FBE for final molasses runs between 300 and 850 rpm — and why the right specification question is never just "what flow?", but "which fluid, at what temperature, with how many solids?".
7. Season and off-season: the calendar that dictates maintenance
A sugar mill runs on a schedule almost no other industry knows: months of continuous 24/7 operation during the season, followed by a long off-season stop. For the pump fleet this creates two critical moments. During the stop, drained and poorly preserved equipment suffers internal corrosion and seal dry-out — proper preservation includes complete drainage, protection of internal surfaces and periodic shaft rotation.
At season start-up, every pump must come back at once, and any forgotten repair becomes a bottleneck with the mill already receiving cane.
The off-season is also the only real window for heavy maintenance — and it is short for the size of the list. This is where a domestic supplier weighs on the result: spare parts in weeks, not import months, decide whether overhauling dozens of pumps fits the window or not. Mills that map the fleet by criticality and close the spares package before the stop enter the next season without improvisation.
8. Summary: which FB pump at each mill stage
Quick reference for specifiers and project engineers:
| Stage / Fluid | FB Series | Why |
|---|---|---|
| Molasses and honey transfer | FBE | Viscosity 10,000-50,000 SSU |
| Cane juice circulation | FBCN | Low viscosity, high flow |
| Vinasse | FBCN (316L SS) | Corrosive (pH 3.5-5.0) |
| Imbibition / wash water | FBCN | Clean water, high flow |
| Thermal oil (evaporators) | FBOT | Up to 350°C, cooled seal |
| Fire protection | Fire NFPA | NFPA 20 + NBR 16704 |
| Viscous additive dosing | FBEI | Low pulsation, smooth flow |