Products

Belt-driven axial fans are ideal for environments where the air may contain dust or moisture, operate at high temperatures, or require adjustable fan speeds. The impeller is directly keyed onto the bearing unit shaft and driven by vee belts enclosed within a tunnel, which isolates them from the air stream. External lubrication points are easily accessible for maintenance. The motor is mounted on an adjustable platform, allowing proper belt tensioning for 205 to 1220 mm diameters.

Ideal for environments where the air may contain dust or moisture RHF Fans supply two types of bifurcated fan, the HD bifurcated fan and the LD bifurcated fan. Where high pressures are required, swollen casings are used to allow larger frame sizes to be fitted, 250 - 1500mm diameter. HD bifurcated fan - With these arrangements, the motor sits in a tunnel which is isolated from the air stream. This tunnel passes all the way through the casing, which allows unrestricted air movement for motor cooling. This is of particular importance for higher-temperature applications. The impellor is mounted onto a precision machined extension shaft, which in turn is mounted onto the motor shaft. Shaft seals are fitted to prevent dust ingress and minimise air leakage into the motor tunnel. These seals are not gas-tight and can be affected by condensation, corrosive chemicals or abrasive materials. Please refer to RHF if special seals are required. The middle section of the fan casing is enlarged to minimise airflow restriction. Coned ends have been carefully proportioned to give a smooth flow from the impellor barrel right through the casing. The use of one-piece spinning for the cone ends ensures accuracy and smooth aerodynamic transitions. These spun cone ends are made from a minimum of 3mm thick steel and are used on all sizes, regardless of whether the casing construction is in mild steel or stainless steel. LD bifurcated fan - With these arrangements, the motor sits in a tunnel which is isolated from the air stream. This tunnel passes all the way through the casing, which allows unrestricted air movement for motor cooling. This is of particular importance for higher-temperature applications. The impellor is mounted onto a precision machined extension shaft, which in turn is mounted onto the motor shaft. Shaft seals are fitted to prevent dust ingress and minimise air leakage into the motor tunnel. These seals are not gas-tight and can be affected by condensation, corrosive chemicals or abrasive materials. Please refer to RHF if special seals are required. This particular fan consists of a cylindrical casing, which is less expensive than the HD type. The flow losses encountered with this design are naturally higher than those experienced with the HD type due to greater restriction of free area. Notwithstanding the restriction, good performance can be achieved with a small penalty on absorbed power. Ancillaries such as spigot flanges, inlet bellmouths, casing feet, and flexible connections are also available. RHF can offer nonstandard arrangements and special fans.

Unlike standard fans, their design complies with EU and UK regulations, ensuring that every component is made from approved materials. This significantly minimises the risk of ignition and explosion in potentially dangerous settings. These fans are certified to operate safely in ATEX-rated hazardous or explosive atmospheres, providing an extra layer of safety and peace of mind. We manufacture ATEX Zones 2 and 22.

Both the No.9 and No.1 models offer a distinct advantage over direct drive systems by enabling operation at non-synchronous speeds without requiring an inverter. Additionally, they can withstand higher temperatures, up to 450°C, when paired with RHF's integral flange-to-flange lagging or insulated plug/bung sections. No.1 Channel Base: This model features a "floor" mounted motor on a channel base, which can be equipped with or without outriggers for added stability. No.1 Pedestal: Also referred to as "Bare-shaft," this unit comes with a "floor" mounted motor, extended pedestal, and pre-fitted shaft and bearings. It is designed to easily install belts, pulleys, drive guards, and motors by others. The shaft and bearings (outside of the airstream) support an overhung impeller. The motor is mounted onto an integral channel frame with a guard, guard support, slide rail unit, and belt drive. The Channel frame comes in two variants: one with outriggers and one without. Outriggers enable easy drilling of foundation holes without marking and then moving the fan. No.9 Plug: This plug is designed to be mounted on top, at the side, or underneath an area (typically for an oven) to facilitate air circulation. Standard models can withstand temperatures up to 450°C, and special versions are available for temperatures up to 650°C. No.9 Monoblock: Features a "floor" mounted motor positioned on the side of the pedestal for convenient installation and operation. Shaft and bearings (outside of airstream) supporting an overhung impeller. The motor is mounted onto an adjustable plate mounted onto four screwed rods. The guard and belt drive are included. Available with Channel Base Frame, with and without outriggers. Size Range Universal 250mm to 900mm (with and without drive side removable impeller) Size Range Fixed Handing 1000mm to 2000mm (2450mm as special) Max temperature 250°C standard (With lagging or "bung" up to 450°C) Arrangements (No.1 Channel Base, No,9 Monoblock -"Flour Mounted". No.9 Plug (up to 450°C as standard) No.1 Pedestal (Fan supplied "bare shaft" i.e. no motor, drive or drive guard).

These feature a motor placed on a pedestal, aligned directly with the impeller hub. However, in the No.7, a shaft and bearing unit, connected via a flexible coupling, separate the motor from the impeller hub. This configuration is often used instead of a direct-driven fan in situations where the fan and motor's physical size make future maintenance a key consideration. With the No.7 arrangement, the fan and impeller can be removed independently of each other, simplifying future maintenance tasks. Size Range Fixed Handing 1000mm to 2000mm (2450mm as special) Max temperature250°C standard (With lagging or "bung" up to 450°C).

The impeller is directly mounted to the motor, which is outside of the airstream. Maximum temperatures are 200°C and 300°C with integral lagging. Size Range Universal - 250mm to 900mm (with and without drive side removable impeller) Size Range Fixed Handing 1000mm to 2000mm (2450mm as special) Size Range Fixed Handing1000mm to 2000mm (2450mm as special) Arrangements (No.4 V - Inlet Mounted, No.4 Pedestal - "Floor Mounted", No.4 Plug (up to 350°C as standard). The increasing use of inverters in conjunction with fans has become the modern “norm” for fan design, with energy savings being made by slowing down your already energy-efficient RHF Smoothflow fan.