Description
Known as one of the pioneers in fan manufacturing, Witt & Sohn has become one of the leading brands in tunnel and subway ventilation systems over the past 20 years. This is due to the continuous development of the following:
- Jet fan 2. Large axial flow fans for fresh air supply and exhaust mode.
Jet fans are available as follows:
- Asymmetric type, with a high performance developed for one direction
- Symmetric type, with partial reversibility (40;; 60;; 90)) in both directions.
Standard jet fans, thrust from 35 N to 3500 N are available. Higher values are possible on request, however, with varying lengths of mufflers, almost any required sound pressure level can be reached. With specially developed impellers (metal bolts, etc.) both tip speed and very high temperature are possible. Photographs of butterfly blades and butterfly hubs are not required but can be made at the customer’s request. The latest generation of jet technology in the collection is now conquering the ERP fronts of EU-Eco-design 2020. The efficiency of these new jet fans is approximately 70, which is significantly higher than the usual levels of market efficiency. Jet fans are tested according to ISO 13 350, axial fans are tested according to ISO 5801. In addition, all fans must pass the normal factory test before delivery. Jet and axial fans are tested and certified according to EN 12 101−3.
| Jet fan | Size: 400 to 1800 mm (larger on request) , Body thickness: 4 – 10 mm, Type of impeller: P, N, M, NR, MR (adjustable step in impeller idle mode) |
| Plan | With input cone (for one direction: GD type / for both directions: GDR type)
With inlet cone and muffler (for one direction: GT type / for both directions: GR type) |
| Material | Butterfly: Aluminum casting corrosion-resistant or Steel impeller
Coating: Steel (S235JRG2, according to EN 10 025) or stainless steel (1.4571 = X6CrNiMoTi17−12−2, 1.4301 = X4CrNi18−10, according to EN 10 088−2) |
| Extinguisher | Steel (S235JRG2 / perforated sheet: stainless steel 1.4571, 1.4301) or Stainless Steel (1.4571, 1.4301) |
| Surface treatment | Painting (eg 2-part epoxy paint)
Hot-dip galvanizing + painting (eg 2-component epoxy paint) Passive welds (stainless steel) |
| Thermal resistance | At the customer’s request (eg 250 ° C / 90 minutes; 200 ° C / 2 hours, etc.)
F200 In accordance with EN 12 101-3, certified by MPA Braunschweig F300 Compliant with EN 12 101-3, certified by MPA Braunschweig F400 Compliant with EN 12 101-3, certification by MPA Braunschweig In the heat test chamber, it is possible to perform all kinds of heat tests according to the customer’s wishes, have GL, TÜV certification, etc. |
| Standard accessories | Banana design (30% more volume in the tunnel with the same power consumption!)
Vibration dampers Protective furnaces Safety wires (Article: 1.4401) Dowels (1.4571 / 1.4529) Tear off Guard Vibration control Guide blades |
| Engine
|
Engine frame size: 63 to 315, Protection class: (IP55, IP65 on request), Bearings: Lubrication for life (on request with the re-lubrication machine), Insulation class: F, H, or special, Temperature resistant motors are tested according to EN 12 101-3 |
Installation structure (compatible with respectable tunnel profile):
Steel (S235JRG2 or stainless steel (1.4571,1.4301, (1.4529))
Market comparison table
A few months ago, in a licensed jet fan laboratory, the fans of several fan manufacturers in Europe were tested as follows:
Reversible models, Muffle (L = 1 x D), Butterfly size 1000 mm, Heat resistance class F400 acc to EN12101-3.
After normalizing the impeller distance, the results are compared. As shown in the following curves, the Witt & Sohn jet fan was the most efficient one.
| Inlet diameter | Up to 1.8 meters |
| Capacity | Up to three hundred and twenty thousand cubic meters per hour |
| Pressure | Up to two thousand eight hundred newtons |
| Temperature resistance | Up to seven hundred degrees Celsius |
