Spray dryers
Pumpable liquids and slurries are atomized into a hot chamber and dried to fine, free-flowing powder in seconds.
- Liquids & slurries
- Uniform, free-flowing powder
- Dyes, chemicals, food, pharma
Dryer Finder – Which Dryer Do I Need?
Spray, paddle, flash, spin flash, fluid bed or agitated thin film dryer? Three questions give you a starting point.
- 24+Years of drying engineering
- 30+Installation, commissioning & service team
- 6Dryer types, one engineering team
- ISO9001:2015 certified
Dryer finder
Which dryer fits your product?
Three quick questions for a starting point. Our process engineers confirm it on your product data or in a pilot trial.
Recommended starting point
Spin flash dryers
Typical products:
General guidance only – the final choice depends on moisture, stickiness, heat sensitivity and capacity. We confirm it on your product data or in a pilot trial.
How they work
How each dryer makes powder
Wet feed in, dry powder out – but the route is different. Pick a dryer and watch the particles.
Acmefil
Spray dryers
- The liquid feed is pumped to an atomizer – a spinning wheel or a nozzle.
- Fine droplets meet hot air in the drying chamber.
- The water evaporates in seconds and each droplet becomes a dry particle.
- Powder leaves through the cone; a cyclone and bag filter collect the fines and clean the air.
- Liquids & slurries
- Uniform, free-flowing powder
- Dyes, chemicals, food, pharma
Typical products: Dyes, detergents, food and dairy powders, ceramics, pharma, herbal extracts
AS Engineers
Paddle dryers
- Wet sludge, paste or slurry enters one end of a jacketed trough.
- Hollow paddle shafts and the jacket carry steam, thermic fluid or hot oil.
- Slowly turning paddles stir, convey and keep exposing fresh product to the hot surfaces.
- A small gas flow carries the vapour away; the dried product discharges at the far end.
- ETP / STP sludge
- Indirect, low gas flow
- Sticky pastes & slurries
Typical products: ETP and STP sludge, pigments, gypsum, salts, starch, polymers
Acmefil
Flash dryers
- A feeder meters loose, crumbly wet solids into a hot-air duct.
- The air carries the particles upward while the moisture evaporates in seconds.
- A cyclone separates the dry powder from the air.
- The exhaust is cleaned in a bag filter or scrubber before it is released.
- Free-flowing wet solids
- Seconds of drying
- Simple, continuous
Typical products: Starch, minerals, pigments, inorganic salts, fillers
Acmefil
Spin flash dryers
- A screw feeder meters wet cake or paste into the base of the chamber.
- Hot air enters tangentially and swirls upward while a rotor breaks the cake into fine particles.
- The particles dry in seconds; a classifier keeps wet lumps in the chamber until they are ready.
- The dry powder is collected in a cyclone and bag filter.
- Filter cake & paste
- Sticky, lumpy feeds
- Pigments, chemicals, sludge
Typical products: Pigment and dye cake, agrochemicals, chemical cake, sludge
Acmefil
Fluid bed dryers
- Wet granules or crystals are fed onto a perforated plate.
- Hot air blows up through the plate and lifts the bed – vibration helps it travel along.
- Every particle is surrounded by hot air and dries evenly; a cooling zone can follow.
- The product discharges at the far end; the exhaust passes a dust collector.
- Granules & crystals
- Gentle, uniform drying
- Vibratory, static & batch
Typical products: Salts, crystals, granules, pharma granulates, fertilizers
Acmefil
Agitated thin film dryers
- A viscous feed enters at the top of a heated cylinder.
- Rotor blades spread it into a thin film on the heated wall.
- The water or solvent evaporates; the vapour goes to a condenser, so solvents can be recovered.
- The concentrated or dried product leaves at the bottom.
- Viscous, heat-sensitive
- Solvent recovery
- Short residence time
Typical products: Resins, intermediates, effluent concentrates, heat-sensitive pastes
Six dryer types
The right dryer for every feed
See what each dryer handles and where to find it on the maker’s site – paddle and sludge dryers at AS Engineers, all others at Acmefil.
Paddle dryers
Indirect heat through hollow paddle shafts dries sludge, pastes and sticky solids gently, with low gas flow and little dust.
- ETP / STP sludge
- Indirect, low gas flow
- Sticky pastes & slurries
Flash dryers
Loose, crumbly wet solids are carried through a hot-air duct and dried in seconds – simple and continuous.
- Free-flowing wet solids
- Seconds of drying
- Simple, continuous
Spin flash dryers
Wet cake, paste and sludge are broken up by a rotor inside a swirling hot-air vortex and leave as dry powder.
- Filter cake & paste
- Sticky, lumpy feeds
- Pigments, chemicals, sludge
Fluid bed dryers
Hot air lifts granular or crystalline wet solids into a gently moving bed for uniform, controlled drying and cooling.
- Granules & crystals
- Gentle, uniform drying
- Vibratory, static & batch
Agitated thin film dryers
A thin film of viscous or heat-sensitive product is wiped over a heated wall – continuous drying with a short residence time.
- Viscous, heat-sensitive
- Solvent recovery
- Short residence time
Compare
Six dryers, side by side
How the feed, drying time, product form and footprint differ.
| Spray dryer | Paddle dryer | Flash dryer | Spin flash dryer | Fluid bed dryer | Agitated thin film dryer | |
|---|---|---|---|---|---|---|
| Feed | Pumpable liquids, slurries, solutions | Sludge, pastes, wet cake, slurries | Loose, crumbly wet solids | Wet cake, filter cake, paste, sludge | Granular, crystalline wet solids | Viscous concentrates, pastes, heat-sensitive liquids |
| How it dries | Droplets atomized into a hot-air chamber | Indirect heat through hollow paddles and jacket | Particles carried in a hot-air duct | Rotor breaks the cake in a hot-air vortex | Hot air fluidizes the bed (vibration helps) | Thin film wiped over a heated wall by rotor blades |
| Drying time | Seconds | Minutes to hours | Seconds | Seconds | Minutes | Short residence, continuous |
| Product | Fine, free-flowing, often spherical powder | Granules or powder | Powder, as fed | Fine powder, de-agglomerated | Dry granules and crystals | Powder, flakes or concentrate |
| Footprint | Large chamber and tall structure | Long horizontal body | Tall duct, simple layout | Compact, vertical | Long, low body | Compact, vertical |
| Main limit | Feed must be pumpable | Larger size per kg of water than flash drying | Not for sticky or lumpy feed | Feed must be screw-conveyable | Feed must fluidize; fines need filtration | Heated surface area limits capacity |
| Typical products | Dyes, detergents, food and dairy powders, ceramics, pharma, herbal extracts | ETP and STP sludge, pigments, gypsum, salts, starch, polymers | Starch, minerals, pigments, inorganic salts, fillers | Pigment and dye cake, agrochemicals, chemical cake, sludge | Salts, crystals, granules, pharma granulates, fertilizers | Resins, intermediates, effluent concentrates, heat-sensitive pastes |
| Typical heating | Hot air – gas, oil, steam or electric heaters | Steam, thermic fluid or hot oil (indirect) | Hot air – gas, oil, steam or electric heaters | Hot air – direct or indirect fired | Hot air, with a cooling zone if needed | Steam or thermic fluid jacket |
Typical behaviour from industry practice; your product sets the real answer – use the dryer finder or send us your product data.
Selection guide
Eight things that decide the dryer
Know these before you ask for a quote – they are what our process engineers ask first.
Feed form
Liquid, slurry, wet cake, paste, sludge or granules – the first filter between the six dryers.
Moisture in and out
The moisture of the feed and the final moisture you need set how much water must be evaporated.
Stickiness and fouling
Sticky or gelatinous products need agitation, back-mixing or a scraped surface so they do not build up on walls.
Heat sensitivity
Colour, flavour or activity at risk? A short residence time or gentler, indirect heating wins.
Powder specification
Particle size, bulk density, flowability and agglomeration decide whether you need powder, granules or flakes.
Capacity
Dryers are sized by water evaporated in kg/hr – not by the weight of the product alone.
Heat source and utilities
Gas, oil, coal, biomass, steam, thermic fluid or electricity – each changes the air or gas flow and the layout.
Safety and environment
Dust explosion risk, solvents, odour and emission limits shape the dust collection and the dryer type.
Quote checklist
What to send for a quote
The more you share, the sharper the recommendation. A lab report or a photo of the wet product helps most.
- Product name and its form – liquid, cake, paste, sludge or granules
- Feed moisture and feed temperature
- Final moisture and the powder you need – particle size, bulk density
- Capacity: feed rate or dry product in kg/hr
- Heat source available – gas, oil, coal, biomass, steam, thermic fluid or electricity
- Hazards – solvents, dust explosion risk, toxicity, odour
- Site location and utilities
Free proposal
Not sure which dryer? Send us your product.
Tell us the feed, moisture and capacity – we recommend the dryer, a budget quote and a pilot-trial option.
