Extruded feed and pet treats dried with heat pumps
How a feed plant drying 6 tonnes of extruded fish feed and 0.5 tonnes of pet treats a day can use a closed-loop heat pump dryer, and what it saves against a diesel-fired dryer.
▶Video: Heat pump dryers for food and agri products
V08 · 2–2.5 minClosed-loop drying of spices, fruit, fish, grain and more
Video coming soon01Problem statement
- Vitamins and fats are heat sensitive. Hot air degrades added vitamins and oxidises fats, so more premix must be added to meet the label.
- Uneven moisture. Wet spots above about 12% moisture grow mould in the bag. Over-dried feed loses weight and money.
- Diesel cost per tonne. Drying is the main fuel use in an extrusion plant and diesel prices move with crude.
- Losses between fuel and process. Burning diesel in a boiler or heater and distributing the heat loses a quarter or more of the fuel's energy before it reaches the process.
- Compliance, safety and handling. Fired equipment brings boiler inspections, fuel storage and unloading, flue emissions and an attendant on every shift.
02Use case
The reference plant extrudes floating fish and shrimp feed, about 6 tonnes a day, and makes meat-based dog chews and treats, about 0.5 tonnes a day. It runs two shifts with drying continuing into the night.
| Product | Drying | Basis | Water removed, kg/day | Conventional heat, kWh/day |
|---|---|---|---|---|
| Extruded fish and shrimp feed | Air 65–70 °C | 6,000 kg/day, 25% → 10% | 1,000 | 1,800 |
| Meat-based pet treats and chews | Air 60–65 °C | 500 kg/day, 60% → 18% | 256 | 461 |
| Total | 1,256 | 2,261 | ||
Conventional hot-air dryers use about 1.8 kWh of heat per kg of water removed. That figure is the baseline the savings are measured against.
03P&ID
Tags: HP heat pump, TK tank, SG steam generator, P pump, PHE plate heat exchanger, TCV temperature control valve, TIC temperature indicating controller (panel), TT temperature transmitter, MT moisture transmitter, PT pressure transmitter, LT level transmitter, FS flow switch, NC normally closed. Process fluids are heated through their own exchanger, coil or jacket.
04Solution
System description
- 3 × SE-AA-DR-21 (63 kW total) heat pump drying modules, removing about 1,256 kg of water a day in roughly 17 running hours.
- The diesel-fired hot-air belt dryer stays connected behind a normally closed valve as standby.
- A closed-loop heat pump dryer supplies air at 65–70 °C and low humidity to the existing belt or tray dryer.
- Feed dries to an even final moisture with a longer, gentler residence time.
- Pet treats dry in a separate chamber section on their own recipe.
Selected equipment
| Model | 3 × SE-AA-DR-21 |
|---|---|
| Heating capacity | 21 kW each, 63 kW total |
| Dehumidifying | about 74 L/h total (pro rata to the published 12–120 L/h range) |
| Drying air | rated 70 °C, 75 °C maximum |
| Refrigerant | R134a |
| Ambient | −5 to 43 °C |
| Water removed per kWh | about 2.4 kg |
Ratings from the Sunniva TDS 2026 data sheets.
Control philosophy
TIC-201 holds air at the recipe temperature for each product. A return-air humidity sensor sets dehumidifying duty. Belt speed or batch time is set from a moisture check at the dryer outlet.
05Energy saving and ROI
Change any input to match a customer's site. Defaults are typical Indian prices for October 2026. The installed cost is a placeholder; replace it with the actual quotation.
| Existing | Heat pump | |
|---|---|---|
| Daily consumption | – | – |
| Annual energy cost | – | – |
| Cost per tonne of feed | – | – |
| CO₂ per year | – | – |
06Benefits
Less vitamin loss
Lower drying temperature protects heat-sensitive vitamins and fats.
Even final moisture
Steady, dry air gives a tighter moisture spread, reducing both mould risk and over-drying.
No combustion near feed
There are no flue gases or burner fire risk in the dryer.
Heat recovered from the moisture
The evaporator condenses water out of the air and the condenser puts that latent heat back into the drying air, so about 2.4 kg of water leaves per kWh of electricity.
Closed loop, clean product
Air recirculates inside the chamber. No dust, smoke or outside humidity reaches the product, whatever the weather.
Built-in redundancy
Several machines share the load. If one is serviced, the others and the storage carry most of the day, with the existing heater in reserve.
07Engineering pointers
Site data to collect
- Products and daily tonnes
- Moisture after extrusion and target moisture
- Present dryer type, residence time and inlet temperature
- Present fuel use per tonne
- Present fuel or electricity use and monthly bill
- Sanctioned electrical load and spare capacity
- Space for the heat pumps and storage, with service access
Design notes
- Throughput. High-throughput kibble dryers that run at 100 °C or more need a longer, larger dryer at 70 °C. Check floor space before conversion.
- Fat and fines. Fat-coated fines collect on coils. Fit filters and a cleaning routine.
Service and warranty
Sunniva has supplied 5,000+ heat pumps since 2012, with nine service technicians across India, including remote sites such as Leh. All components carry a one-year warranty.
Talk to us
Extruded feed and pet treats dried with heat pumps
How a feed plant drying 6 tonnes of extruded fish feed and 0.5 tonnes of pet treats a day can use a closed-loop heat pump dryer, and what it saves against a diesel-fired dryer.
▶Video: Heat pump dryers for food and agri products
V08 · 2–2.5 minClosed-loop drying of spices, fruit, fish, grain and more
Video coming soon01Problem statement
- Vitamins and fats are heat sensitive. Hot air degrades added vitamins and oxidises fats, so more premix must be added to meet the label.
- Uneven moisture. Wet spots above about 12% moisture grow mould in the bag. Over-dried feed loses weight and money.
- Diesel cost per tonne. Drying is the main fuel use in an extrusion plant and diesel prices move with crude.
- Losses between fuel and process. Burning diesel in a boiler or heater and distributing the heat loses a quarter or more of the fuel's energy before it reaches the process.
- Compliance, safety and handling. Fired equipment brings boiler inspections, fuel storage and unloading, flue emissions and an attendant on every shift.
02Use case
The reference plant extrudes floating fish and shrimp feed, about 6 tonnes a day, and makes meat-based dog chews and treats, about 0.5 tonnes a day. It runs two shifts with drying continuing into the night.
| Product | Drying | Basis | Water removed, kg/day | Conventional heat, kWh/day |
|---|---|---|---|---|
| Extruded fish and shrimp feed | Air 65–70 °C | 6,000 kg/day, 25% → 10% | 1,000 | 1,800 |
| Meat-based pet treats and chews | Air 60–65 °C | 500 kg/day, 60% → 18% | 256 | 461 |
| Total | 1,256 | 2,261 | ||
Conventional hot-air dryers use about 1.8 kWh of heat per kg of water removed. That figure is the baseline the savings are measured against.
03P&ID
Tags: HP heat pump, TK tank, SG steam generator, P pump, PHE plate heat exchanger, TCV temperature control valve, TIC temperature indicating controller (panel), TT temperature transmitter, MT moisture transmitter, PT pressure transmitter, LT level transmitter, FS flow switch, NC normally closed. Process fluids are heated through their own exchanger, coil or jacket.
04Solution
System description
- 3 × SE-AA-DR-21 (63 kW total) heat pump drying modules, removing about 1,256 kg of water a day in roughly 17 running hours.
- The diesel-fired hot-air belt dryer stays connected behind a normally closed valve as standby.
- A closed-loop heat pump dryer supplies air at 65–70 °C and low humidity to the existing belt or tray dryer.
- Feed dries to an even final moisture with a longer, gentler residence time.
- Pet treats dry in a separate chamber section on their own recipe.
Selected equipment
| Model | 3 × SE-AA-DR-21 |
|---|---|
| Heating capacity | 21 kW each, 63 kW total |
| Dehumidifying | about 74 L/h total (pro rata to the published 12–120 L/h range) |
| Drying air | rated 70 °C, 75 °C maximum |
| Refrigerant | R134a |
| Ambient | −5 to 43 °C |
| Water removed per kWh | about 2.4 kg |
Ratings from the Sunniva TDS 2026 data sheets.
Control philosophy
TIC-201 holds air at the recipe temperature for each product. A return-air humidity sensor sets dehumidifying duty. Belt speed or batch time is set from a moisture check at the dryer outlet.
05Energy saving and ROI
Change any input to match a customer's site. Defaults are typical Indian prices for October 2026. The installed cost is a placeholder; replace it with the actual quotation.
| Existing | Heat pump | |
|---|---|---|
| Daily consumption | – | – |
| Annual energy cost | – | – |
| Cost per tonne of feed | – | – |
| CO₂ per year | – | – |
06Benefits
Less vitamin loss
Lower drying temperature protects heat-sensitive vitamins and fats.
Even final moisture
Steady, dry air gives a tighter moisture spread, reducing both mould risk and over-drying.
No combustion near feed
There are no flue gases or burner fire risk in the dryer.
Heat recovered from the moisture
The evaporator condenses water out of the air and the condenser puts that latent heat back into the drying air, so about 2.4 kg of water leaves per kWh of electricity.
Closed loop, clean product
Air recirculates inside the chamber. No dust, smoke or outside humidity reaches the product, whatever the weather.
Built-in redundancy
Several machines share the load. If one is serviced, the others and the storage carry most of the day, with the existing heater in reserve.
07Engineering pointers
Site data to collect
- Products and daily tonnes
- Moisture after extrusion and target moisture
- Present dryer type, residence time and inlet temperature
- Present fuel use per tonne
- Present fuel or electricity use and monthly bill
- Sanctioned electrical load and spare capacity
- Space for the heat pumps and storage, with service access
Design notes
- Throughput. High-throughput kibble dryers that run at 100 °C or more need a longer, larger dryer at 70 °C. Check floor space before conversion.
- Fat and fines. Fat-coated fines collect on coils. Fit filters and a cleaning routine.
Service and warranty
Sunniva has supplied 5,000+ heat pumps since 2012, with nine service technicians across India, including remote sites such as Leh. All components carry a one-year warranty.