For sterile applications

The Novalobe range of pumps has been designed for bi-directional flow in accordance with the GMP, FDA, EHEDG, QHD and 3A industry standards and incorporates the following accepted principles for sterile design:

In addition, the rotary lobe positive-displacement pump design offers two further unique characteristics. Firstly, it utilises a synchronised gear assembly, which guarantees zero contact between the contra-rotating, pumping rotors by means of a pre-determined clearance. This eliminates possible shedding of pump material into the pumped media – a cause of contamination and a problem often associated with eccentric screw, peristaltic, gear and flexible impeller pump types.

Secondly, the pumping chamber is fully swept, making it suitable for even the most stringent CIP (clean in place) and SIP steam (sterilise in place) regimes. There are no potential trapped volumes of liquid, dead zones or crevices within the fully swept chamber, ensuring the highest sterile standards are maintained at all times.

The Novalobe range is designed with a flush front cover and flush rotor fixing screw with a sealed O-ring arrangement in accordance with EHEDG design guidelines. The front cover can incorporate ancillary equipment such as integral pressure relief valves, thermal jackets, aseptic sealing systems and “smart” pump data acquisition technology.

Whilst rotary lobe pumps are traditionally mounted with horizontal connections to comply with the sterile requirements for full drainability, this pump must be rotated so that the connections are in the vertical plane. The Novalobe has multi-mount feet, which can easily change the connection orientation to accommodate both requirements. The feet also incorporate a degree of height adjustment for easy alignment with drive motors and couplings, eliminating the need for time-consuming shimming.

A unique rotor mounting arrangement has been introduced with the Novalobe, incorporating the use of precision-ground cyl-inders as drive and rotor location devices. The advantage of this is greater geometrical tolerance control, providing reduced vibration and associated fretting wear, lower noise levels and reduced life cycle costs. The arrangement is totally sealed from both the pump and the seal flush media.

Rotor profile options are available to suit particular product characteristics, including single-wing for high-viscosity dough-like products, bi-wing for general applications and cycloidal multi-lobe for low pulsation, low NPIPr, low noise and gentle handling of shear-sensitive products. All rotor types are designed for complete interchangeability and capable of 150 °C operating temperature as standard.

Novalobe mechanical seals are specifically designed for applications where viscosities can be high and speeds low, leading to high starting torque characteristics – an important consideration for pump selection. The pumps are equipped with front loading, single, flushed and double seal arrangements in sleeved cartridge formats, offering user-friendly seal inspection and servicing and minimising down time. The seals are positioned directly in the flow of the pumped media and cleaning solutions, and are crevice-free in compliance with the criteria for sterile engineering. The replaceable shaft sleeve design reduces life cycle costs and simplifies the seal replacement process. The material options available for the mechanical seal face are carbon versus silicon carbide, offering low heat input to the pumped media due to its low coefficient of friction. For high-specification sterile applications, silicon carbide versus silicon carbide provides a non-shedding seal solution, maintaining a high degree of pumped media purity and conforming to accepted standards.

The pump rotor cases are fitted with large port sizes as standard with any commercially available connection types, including threaded, flanged and clamp designs. These cases can be supplied to suit both imperial and metric formats, eliminating the need for pipe adapters and maintaining uniformity across port dimensions. For high-viscosity applications, an enlarged rectangular inlet option is available to further reduce the NPIPr characteristics. With this option the pump can be located directly on a conical-bottomed vessel to ease product flow into the pump.

Pump internal surface finish is of major importance in sterile production facilities, where it must be smooth, free from mechanical damage and niches and offer as little adhesion to foreign particles as possible. The standard surface finish is #0.8 µm Ra. With optimised machining rates and electro-polishing, this can be improved to <0.4 µm Ra and duly certified. Novalobe pumps are available in 316 low-carbon stainless steel 1.4404, low-ferrite 1.4435, Hastelloy and other special alloys. Material traceability certification can be provided to EN 10.204 3.1 with FDA approval for the seal materials.

A comprehensive testing program provides confirmation of the pump operating characteristics, flow dynamics, noise levels and NPIP requirements. Mechanical seal test rigs allow specific tests to be carried out on individual client products to verify seal suitability prior to installation.

Hall 8.0, Booth B25

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The most important technical details of Hilge’s rotary lobe pump are: