In brewery brewhouses, wort cooling traditionally uses a two-stage process of "tap-water pre-cooling + ice-water secondary cooling," which consumes large amounts of water and power. This project uses a SAMIT single-stage ice-water cooling plate heat exchanger to merge the two stages into one, delivering significant energy savings.
1. Project Background
Customer
A large brewery in South China with an annual output of 250,000 kL, brewhouse with 6 batches × 150 kL/batch.
Original Process
Two-stage cooling: tap water reduced wort from 95 ℃ to 40 ℃ (water consumption 4× wort volume), then ice water cooled it down to 8 ℃.
Pain Points
- Tap water consumption 480,000 t/year
- High chiller load and large power consumption
- 48 ℃ warm water wasted (could not be reused)
2. Technical Solution
SAMIT retrofit solution: use 2 ℃ ice water to cool 95 ℃ wort to 8 ℃ in a single pass; the ice water is heated to 80 ℃ and sent directly to the brewhouse hot-water tank for reuse as mashing liquor.
| Comparison Item | Two-stage cooling (original) | Single-stage cooling (new) |
|---|---|---|
| Water consumption | 4 × wort volume | 1.2 × wort volume (ice water) |
| Cooling medium | Tap water + ice water | Ice water only |
| Heat exchanger | Two small shell-and-tube units | 1 SAMIT BR0.5 · 65 m² |
| Warm-water reuse | Not feasible (temperature too low) | 80 ℃ hot water → mashing liquor |
| K value | 1500 W/(m²·K) | 2800 W/(m²·K) |
3. Process Flow
4. Implementation Process
- Design: Performed hydraulic calculations for the simultaneous cooling of 4 out of the 6 brewhouse batches and confirmed that a single 65 m² plate heat exchanger was sufficient
- Shutdown retrofit: Completed installation of the plate heat exchanger, ice-water piping modifications, and control-system upgrades during a 14-day equipment maintenance window
- Performance test: Wort throughput 150 kL/h, cooled from 95 ℃ to 8 ℃ in only 45 min, achieving 105% of the design value
Key design: SAMIT shallow-corrugation (chevron angle 60°) plates were chosen over deep-corrugation plates because wort contains hop resins and coagulated protein; deep corrugations clog easily and are difficult to clean by CIP. Shallow corrugations offer lower pressure drop and are cleaning-friendly.
5. Operating Results
Water Saving
Annual tap-water savings of 190,000 t, reducing water bills by 760,000 RMB.
Power Saving
Chiller load reduced by 30%, saving 1.8 million kWh/year.
Heat Recovery
80 ℃ hot water is fully reused as mashing liquor, equivalent to an annual energy saving of 800 t standard coal equivalent.
6. Lessons Learned
The core of energy saving in the brewing industry lies in the brewhouse. Single-stage wort cooling replacing two-stage cooling has become an industry standard, yet many older breweries remain unretrofitted. This project demonstrates that at a scale of 150 kL/batch, the combination of a single SAMIT BR0.5 65 m² plate heat exchanger + hot-water tank reuse can keep the payback period within 14 months.