Definition
A parallel multi-arm steam-distribution-manifold configuration for wide duct cross-sections (>1500 mm); the large-flow variant of the SKD manifold family (Neptronic Multi-Steam).
Detailed Explanation
A steam distribution rack (multi-pipe manifold, steam grid) is a parallel multi-arm distribution system used in wide-duct or large-room applications where a single long manifold is insufficient. Typical configuration: main steam feed + 2–8 parallel distribution arms with 200–400 mm spacing between arms. The Neptronic Multi-Steam™ family is the branded variant. Typical capacity: 50–500+ kg/h.
Why It Matters
A single manifold arm cannot exceed 75–85% of duct width (manufacturing, transport, structural limits). For ducts over 1500 mm a single arm is insufficient; steam concentrates on one side, starving the other. A multi-pipe rack solves this: (1) Coverage — even distribution across wide ducts. (2) Uniformity — the downstream sensor sees equal RH at 4–8 points (±1%). (3) Shorter absorption distance — parallel arms release steam through many low-flow jets; small droplets evaporate quickly. (4) Redundancy — if one arm clogs, the others can maintain capacity.
Practical Example
A weaving-hall AHU in Bursa: 2500×800 mm duct, flow 35,000 m³/h, velocity 4.9 m/s, target RH 55%, capacity 220 kg/h. A single arm is insufficient (max 2.1 m); NKT designed a 4-arm Neptronic SKD-MS rack (each arm 1.8 m × 25 jets, 300 mm spacing). Absorption distance 2.3 m, downstream 4-point RH 54.8/55.1/55.3/54.9% (±0.3% uniformity). After commissioning, weaving stayed in-spec and product defect rate dropped from 1.2% to 0.3%.
Engineering Note
Rack design rules: (1) Arm count = duct width (mm) / 400 approximately; 1,500 mm → 3–4 arms, 2,500 mm → 5–6 arms. (2) Arm spacing 200–400 mm; too close → turbulence collision, too wide → uneven distribution. (3) All arms identical in length and jet count; flow distribution must be balanced via the main feed. (4) Jacketed (insulated) arms are preferred for condensate control, particularly when total rack length exceeds 3 m. (5) Drain slope (>1%) and a condensate trap are required per arm.
NKT Application Link
NKT designs Neptronic SKD and Multi-Steam™ rack configurations together with the upstream Neptronic steam humidifier (SKE4, SKS4, SKG4); rack length, arm count and jets are sized per site. During commissioning, 4–8 point RH measurements report uniformity. The NKT - Climate Track platform provides multi-sensor trend logs; rack performance drift is verified during the annual periodic-maintenance contract.
