Case studies · Pharmaceuticals · South Gujarat
Two smart heatless dryers at a pharma plant: −40 °C PDP held, purge cut from 18 % to 8 %
Pharmaceutical formulations plant, South Gujarat · 2 × AIRS smart heatless dryers with TSE Control, with filters
- −40 °C PDP on both dryers (at commissioning and in service)
- 18 → 8 % Purge air (93 m³/h handed back to the plant)
- ₹8.4 L Saved per year (₹41.9 lakh over five years)
- 64 t CO₂ avoided a year (90 MWh not drawn)
The challenge
A pharmaceutical formulations plant in hot, humid South Gujarat needed instrument and product-contact air at −40 °C pressure dew point, with air reaching the dryers at 40–47 °C. A conventional heatless dryer meets −40 °C — by venting about 18 % of the air it dries, on a fixed clock, whether the plant is busy or quiet.
What AIRS did
- Two complete smart heatless packages, each sized for 275 cfm at 9 barg, with its own 0.01 µm coalescing pre-filter and 1 µm particulate after-filter.
- TSE Control watches the outlet PDP: each tower keeps adsorbing while the air stays dry, and the dryer holds in standby once −40 °C is reached — restarting by itself when needed.
- Extruded aluminium towers, a swirl diffuser that spreads the air over the whole desiccant bed, and a low-loss valve manifold: 0.2 bar across the dryer.
- Energy saving worked out for the client's own duty and tariff in the offer, before the order was placed.
The result
- −40 °C PDP reached at commissioning on both dryers and confirmed again in operation.
- Purge cut from 18 % to 8 % — 56 % less, 93 m³/h (55 cfm) of dried air kept in the plant every hour.
- 10.3 kW less compressor power, round the clock: ₹8.4 lakh a year, ₹41.9 lakh over five years and 64 t CO₂ a year.
- The client has since come back to AIRS for zero air loss drains, dryer filter kits and service.
Both dryers, per year (8,760 h)
| Fixed-timer heatless | AIRS with TSE Control | |
|---|---|---|
| Purge air | 18 % | 8 % |
| Air vented | 168 m³/h | 75 m³/h |
| Compressor power for purge | 18.5 kW | 8.2 kW |
| Energy a year | 162,078 kWh | 72,035 kWh |
| Cost a year | ₹15.1 lakh | ₹6.7 lakh |
| Saving | — | ₹8.4 lakh |
From offer to repeat orders
- Jul 2024: Offer with the purge saving worked out for the plant's duty
- Sep 2024: Order for both dryer packages, filters included
- Nov–Dec 2024: Both packages supplied to site
- Jan 2025: Commissioned — −40 °C PDP reached on both dryers in PDP control
- Feb 2025: Performance check: −40 °C confirmed in operation
- 2025–26: Repeat orders: zero air loss drains and dryer filter kits
Basis of calculation
Client tariff ₹9.3 per kWh · 2 × 275 cfm design flow = 934 m³/h · 8,760 h a year · compressor 0.11 kWh per m³ · grid 0.71 kg CO₂ per kWh. 18 % is the average purge of a heatless dryer of this size on a fixed timer at full flow.
At a glance
| Dryers | 2 × smart heatless, TSE Control |
|---|---|
| Design flow | 275 cfm each at 9 barg |
| Pressure range | 4–14 barg |
| Inlet air | 40–47 °C |
| Required PDP | −40 °C |
| Pressure drop | 0.2 bar |
| Filters | 0.01 µm pre · 1 µm after |
| Commissioned | January 2025 |
About the equipment · Book an energy saving assessment
Client name withheld under the AIRS confidentiality policy. References are shared on request with the client's consent.
More results
- Zero purge dryer at a tyre plant: −28.9 °C PDP on a −20 °C design, ₹28.9 lakh a year saved — Tyres & rubber, Maharashtra: ₹28.9 L saved per year vs heatless
- Smart heatless dryer through peak monsoon: −51.7 °C PDP average on a −40 °C design — Speciality chemicals, Central India: −51.7 °C average PDP in monsoon