You can source tray dryers, continuous belt dryers, fluid bed dryers, spray dryers, drum dryers, vacuum dryers and freeze dryers from Indian makers. The right type depends on the form of your product and how sensitive it is to heat.
Gujarat's dehydrated onion industry around Mahuva is one example of local demand. It runs on multi-stage belt dryers, so makers in the state have long experience with that design.
The main dryer types
- Tray dryers hold product on trays in a heated cabinet. They suit small batches, trials and many different products.
- Belt or conveyor dryers carry sliced or diced product through several heated zones. They suit continuous drying of vegetables, fruit and herbs.
- Fluid bed dryers blow hot air up through granules so they float and dry quickly and evenly. They are common in pharma and for granular foods.
- Spray dryers atomise a liquid into hot air and collect a powder. They suit milk, juice, extracts and flavours.
- Drum dryers spread a paste or slurry on a heated drum and scrape off flakes.
- Vacuum dryers dry at lower temperature under reduced pressure, which protects heat-sensitive material.
- Freeze dryers remove water from frozen product under vacuum. They keep flavour and structure best, but run slowly and use more energy.
Heat source and energy
Dryers can use steam, thermic fluid, electric heaters, or gas or diesel burners. For food, heat usually reaches the air through a heat exchanger, so combustion gases do not touch the product.
Steam and thermic fluid need a boiler or heater, which may be a separate purchase with its own safety rules in your country. Electric heating is simple but can need a large supply. Energy is one of the largest running costs of a dryer. A useful comparison is the energy used per kilogram of water removed. Ask each maker for that figure at your design conditions, along with insulation details and any heat recovery.
What to check before you buy
- The design basis: input moisture, output moisture and output in kilograms per hour of dry product.
- Product contact surfaces in suitable stainless steel, as covered in 304 or 316 for contact parts.
- Even airflow across trays or belt width, because uneven drying causes wet spots and mould.
- Separate temperature control for each zone, with recorded readings.
- Access for cleaning belts, ducts and corners where product collects.
- A drying trial with your own raw material, with moisture measured before and after.
Fitting the dryer into a plant
A dryer needs space, fuel or steam, exhaust ducting and often a large electrical load. Plan these early, as described in civil and utility requirements. If you need washing, cutting and packing as well, compare a single supplier for the full line using turnkey processing lines.
Next step
We find dryer makers with reference installations, arrange trials with your product and check the machine before it ships. To discuss your project, book a free sourcing review.