Definition

A humidifier that produces steam by boiling water with heater elements in a stainless-steel steam tank. Because current does not flow through the water there is no conductivity requirement; it runs on any water including RO/DI. Power is modulated 0–100% continuously via SSR; per Neptronic data, modulating control achieves ±1% RH. The Neptronic SKE4 (5–120 kg/h) is an example of this type.

Detailed Explanation

Operating principle: 1. Water enters the stainless-steel steam tank through the fill valve. 2. Heater elements immersed in the tank boil the water at atmospheric pressure. 3. The steam travels by hose or pipe to an in-duct distributor (S.A.M., Multi-Steam™) or a space distribution unit (SDU). 4. Periodic draining removes minerals that concentrate in the tank.

Power is switched at zero voltage crossing by an SSR (solid-state relay) and modulated 0–100% continuously. Per Neptronic data, modulating control achieves ±1% RH and on/off control ±5% RH.

Electric steam generation uses about 0.75 kWh/kg; the figure is the same for electrode and resistive units.

Why It Matters

• Water flexibility: being able to run on RO/DI water is an advantage in hygiene-critical areas (pharma, hospitals, laboratories) where mineral carry-over and maintenance load must be minimised. • Predictable capacity: capacity does not depend on water conductivity; it is set by the heater-element power. • Maintenance: steam-tank cleaning and drain settings planned around water quality; no cylinder replacement.

Engineering Note

• Safety margin: 15–25% (20% in practice); example: 25 kg/h calculated → +20% = 30 kg/h. • Steam hose: ≤ 5 m in total; at least 2% slope on descending sections and at least 15% on rising sections. • High-limit humidity sensor: set ≈ 90% RH, at least 4.6 m after the distributor. • Drain: at least 25 mm air gap, pipe rated to 100 °C, a drain cooler where needed. • Service clearances (SKE4): front ≥ 1.2 m, left side ≥ 0.3 m, top ≥ 0.5 m.

NKT Application Link

For this application NKT – Nem Kontrol Teknolojileri supplies the Neptronic SKE4 resistive steam humidifier and, where boiler steam is available, the Neptronic SKS4 steam-to-steam humidifier. Unit-selection support is based on space conditions, humidification load and the feed-water analysis; technical service and spare parts are provided. Design, installation and commissioning remain with the facility's designer and contractor.