At a glance
- Type
- Desiccant (adsorption) dryer
- Architecture
- Twin-tower, pressure-swing or heated regeneration
- Regeneration variants
- Heatless / Micro-heat / Low-purge blower / Zero-purge blower
- Flow range
- 1.6 – 87 m³/min
- Rated pressure
- 8 bar(g)
- Cooling
- Air-cooled or water-cooled
Overview
DRYTECH DT is the desiccant (adsorption) compressed-air dryer range for duties where the required pressure dew point lies below what a refrigerated dryer can hold. Wet compressed air passes through a vessel of desiccant beads; water vapour adheres to their surface by physical adsorption. The machine runs two towers and switches between them — one dries while the other regenerates. Four regeneration variants cover the trade-off between purge air loss, electricity cost and machine complexity.
Model range
DRYTECH DT covers 36 models in four regeneration variants, from 1.6 to 87 m³/min nominal inlet flow, rated 8 bar(g), air- or water-cooled.
Heatless
DT-1.6 – DT-34 — 10 models
- Flow range
- 1.6 – 34 m³/min
- Regeneration
- Pressure-swing, no heater
- Best for
- Small flow or intermittent duty
Micro-heat
DT-1.6H – DT-34H — 10 models
- Flow range
- 1.6 – 34 m³/min
- Regeneration
- Heated purge stream
- Best for
- Mid-size with long run hours
Blower regeneration
DT-17B – DT-87B / DT-17P – DT-87P — 16 models
- Flow range
- 17 – 87 m³/min
- Regeneration
- External blower, near-zero purge
- Best for
- Large continuous flow
Technology
Technology Platform
DryTech DT uses desiccant adsorption to remove water vapour from compressed air. The machine contains two towers packed with desiccant beads (typically activated alumina or molecular sieve). Wet compressed air flows upward through one tower; water vapour adheres to the surface of the desiccant beads by physical adsorption.
Four Regeneration Variants
The four DryTech DT variants differ in how they pay for regeneration — in compressed air, in electricity, or in machine complexity:
Why Not a Refrigerated Dryer?
Refrigerated dryers cool the compressed air to condense water, then separate the condensate. They hold a pressure dew point around +3 °C — the practical limit of refrigeration without freezing.
More technical detail
Technology Platform
When the desiccant in the first tower becomes saturated, the machine switches to the second tower. The first tower then regenerates — the desiccant is dried by reducing pressure (pressure-swing regeneration) or by passing heated air through the bed (heated regeneration). The two towers alternate continuously, providing a steady supply of dried air.
Four Regeneration Variants
No blower variant is issued below 17 m³/min. The heatless and micro-heat ladder stops at 34 m³/min.
- Heatless (DT-1.6 – DT-34) — pressure-swing regeneration. The simplest design: no heater, no blower. Regeneration is achieved by depressurizing the saturated tower and purging a small fraction of dried product air through it. Lowest purchase cost, highest purge air loss. 1.6–34 m³/min, 10 models.
- Micro-heat (DT-1.6H – DT-34H) — heated purge stream cuts air loss versus heatless. A small heater warms the purge air, improving regeneration efficiency and reducing the volume of purge air required. Mid-range purchase cost, lower purge air loss than heatless. 1.6–34 m³/min, 10 models.
- Low-purge blower (DT-17B – DT-87B) — external blower drives heated ambient air through the bed. No product air is used for regeneration; instead, ambient air is drawn by a blower, heated and passed through the saturated tower. Lowest purge air loss (near zero), but blower adds complexity and maintenance. 17–87 m³/min, 8 models.
- Zero-purge blower (DT-17P – DT-87P) — product-air consumption near zero. Same blower arrangement as low-purge, but with further optimisation to minimise or eliminate product air loss. Highest purchase cost, lowest operating cost for continuous duty. 17–87 m³/min, 8 models.
Why Not a Refrigerated Dryer?
Desiccant dryers reach dew points of −20 °C to −70 °C, depending on the desiccant grade and regeneration method. They are required for:
- Instrument and control air in outdoor or cold-climate installations
- Food, beverage and pharmaceutical process air where moisture causes product rejection
- Electronics and semiconductor manufacturing where moisture causes surface defects
- Laser cutting assist air where moisture causes beam instability
- Pneumatic conveying of hygroscopic product (e.g., plastics pellets, powder)
- Painting and coating where moisture causes surface defects
Upstream Pre-Drying with Refrigerated Dryer
If your existing refrigerated dryer holds +3 °C dew point, it should stay — as an upstream pre-drying stage. A refrigerated dryer removes bulk moisture cheaply and lowers the inlet temperature to the desiccant dryer. This reduces the bed load on the desiccant dryer, extends desiccant life and reduces regeneration energy. The desiccant dryer then polishes the air to the required low dew point.
The two-stage arrangement (refrigerated pre-dryer + desiccant polisher) is the standard configuration for low-dew-point applications.
Required Filtration
Desiccant dryers require two filtration stages — neither is optional:
Add a carbon or high-efficiency stage where the duty is oil-sensitive (e.g., food, pharmaceutical, electronics).
- Coalescing prefilter — upstream of the dryer, removes oil aerosol and liquid water. Oil contaminates the desiccant bed, reducing its capacity and life. Liquid water causes thermal shock and mechanical degradation of the beads. The prefilter protects the desiccant.
- Particulate afterfilter — downstream of the dryer, removes desiccant fines (dust from the beads). Desiccant beads generate dust over time from thermal cycling and mechanical attrition. The afterfilter prevents this dust from reaching the downstream system.
Selection Logic
DryTech DT selection is based on five parameters:
Choose the capacity step at or above the corrected flow, then confirm the per-model dew point with SIND.
- Required pressure dew point (°C): determines the desiccant grade and regeneration method.
- Actual delivered flow at dryer inlet (m³/min): size on actual flow at operating pressure, not the compressor nameplate.
- Inlet pressure and temperature: higher inlet temperature increases bed load; correct the flow for inlet conditions.
- Ambient conditions: affects cooling requirements for air-cooled models.
- Annual operating hours: continuous duty favours blower variants (lower operating cost); intermittent duty favours heatless (lower purchase cost).
Selection & quote checklist
- Required pressure dew point (°C): determines the desiccant grade and regeneration method.
- Actual delivered flow at dryer inlet (m³/min): size on actual flow at operating pressure, not the…
- Inlet pressure and temperature : higher inlet temperature increases bed load; correct the flow for inlet…
- Ambient conditions : affects cooling requirements for air-cooled models.
- Annual operating hours : continuous duty favours blower variants (lower operating cost); intermittent duty favours heatless…
FAQ
How do I select a model?
Set the required pressure dew point first, then actual delivered flow at the dryer inlet, inlet pressure and temperature, ambient, and annual hours. Those five determine the variant.
Which regeneration variant?
Small flow or intermittent duty: heatless. Mid-size with long run hours and no appetite for blower maintenance: micro-heat. Large continuous flow where purge air dominates cost: low-purge or zero-purge blower. Both blower variants start at 17 m³/min; there is no smaller one.
Why not a refrigerated dryer?
Refrigeration condenses water and is bounded by freezing; it holds a dew point around +3 °C. Anything below that, or any outdoor line in a cold climate, needs adsorption drying.
Can my existing refrigerated dryer stay?
Usually yes, and it should. Upstream as a pre-drying stage it removes bulk moisture cheaply and lowers inlet temperature, which reduces bed load and extends desiccant life.
What filtration is required?
A coalescing prefilter for oil aerosol and liquid water, and a particulate afterfilter for desiccant fines. Neither is optional. Add a carbon or high-efficiency stage where the duty is oil-sensitive.
More questions
What maintenance should I plan for?
Drains and silencers on a short interval; switching valves and the desiccant bed on a longer one. Budget bed replacement as a consumable. Intervals and part numbers depend on the model — request the service manual.
Can I get 60 Hz or other voltage?
Yes, on request. Confirm voltage, frequency and phase with your SIND representative before order.
Ownership & service
Energy, maintenance and service
Target Industries and Markets
DryTech DT is specified where the required pressure dew point lies below what a refrigerated dryer can hold:
- Instrument and control air — outdoor and cold-climate pipework where moisture freezes and blocks valves.
- Food, beverage and pharmaceutical process air — where moisture causes product rejection or microbial growth.
- Electronics and semiconductor manufacturing — where moisture causes surface defects or oxidation.
- Laser cutting assist air — where moisture causes beam instability or lens contamination.
- Pneumatic conveying of hygroscopic product — plastics pellets, powder, where moisture causes clumping or blockage.
- Painting and coating — where moisture causes surface defects (fish eyes, blushing).
- Whole-site central plant air — where the site requires a low dew point for multiple applications.
Energy and Total Cost of Ownership
The total cost of ownership for a desiccant dryer turns on three items: purchase cost, regeneration energy cost and desiccant replacement cost.
Selection advice: small flow or intermittent duty favours heatless (low purchase cost). Mid-size with long run hours and no appetite for blower maintenance favours micro-heat. Large continuous flow where purge air dominates cost favours low-purge or zero-purge blower.
- Purchase cost — heatless is lowest; blower variants are highest.
- Regeneration energy cost — heatless loses purge air (compressed air is energy); micro-heat uses electricity to heat the purge; blower variants use electricity to drive the blower and heat ambient air. For continuous duty at high flow, blower variants typically offer the lowest operating cost despite higher purchase cost.
- Desiccant replacement cost — desiccant beads have a finite life (typically 3–5 years, depending on inlet conditions and maintenance). Budget bed replacement as a consumable. Upstream pre-drying with a refrigerated dryer extends desiccant life.
Specifications are typical values. Pressure dew point holds only at its reference conditions — Nominal capacity is not a corrected flow.
