Pumping: aseptically and gently

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OMAC lobe pumps with external pressure relief valve.

From liquid food products to more viscous ones, even abrasive ones or containing parts, the application range of OMAC volumetric lobe pumps is very wide.

With its B series, OMAC offers AISI 316L stainless steel volumetric lobe pumps assembled on a cast iron gear box which has a protective coating in epoxy paint finish. These pumps prevent the contamination between the pumped fluid and the gearbox lubricant thanks to the chamber separating the rotor case and gear box. The base of the gearbox is designed to make installation easier for connecting into pipelines. The lobe pump is modular in design so that the main parts (rotors, seals) can be added or exchanged according to application needs.

Mechanical parts are in oil bath, rigid and compact, with double pre-assembled tapered roller bearings, oversized shafts, gears and support, to achieve tighter tolerances and ensure the pump performance and reliability. The rotors rotate in the opposite direction without touching. This feature prevents metal particles from polluting the product, minimizes mistreatment (lamination, cutting) of the product itself. There are many special executions derived from the standard one, to meet the multiple needs of the food industry.

B series model 100: Trolley pump with stainless steel panel, complete with inverter and remote control.

Special executions

Lobe pumps in aseptic versions provide sterile, steam or liquid barriers on the end cover, shaft seals and suction/discharge ports. This type of pump is used in the food and pharmaceutical sterilised product packaging areas where it is important that the product is not contaminated by bacteria or micro-organisms during transfer. The pump with enlarged mouth allows highly viscous products such as semi-solid pastes or mixtures containing semi-solid pieces to be pumped, In these cases the pump is generally positioned with the port on a vertical axis in order to allow the entry of the product under gravity directly beneath the hopper.

For processing products that need to be pumped at a constant temperature (glucose, chocolate, melted fats, butter), the B series provides pumps with inter-spaced body for the circulation of heating or cooling liquid. Even the lid can be heated or cooled with the same jacket on the body. For the transfer of very corrosive liquids, the pumps can be manufactured with wetted parts in Titanium, Monel or Hastelloy. Models B325, B330 and B390 can be installed on road tankers thanks to the flanged gear cover directly coupled to hydraulic motor. These pumps are available with bare shaft or complete with motor, power station and control system.

Motorization and by-pass

Omac volumetric lobe pumps can be supplied with hygienic by-pass or pressure relief valves. This device protects the pump from pressure peaks or restrictions in the discharge and assures excess liquid deviation during CIP and SIP. The by-pass can be manually selected as a flow regulator in order to pass product without changing the pump speed. This valve can be incorporated in the end cover that replaces the standard cover, or it can be incorporated in the discharge pipework, relieving excess pressure by by-passing product through a loop back to the suction side.

The bypass on the lid is sanitary, works in both directions of rotation without intervention and is available on models B100 to B550. All models of the B series can be fitted with an external pressure relief valve in order to recycle the whole pumped product (sensitive products). Motorized ready-to-use pumps feature an AISI 304 stainless steel or painted iron base with elastic coupling, joint cover and various accessories.

Power transmission can be variable speed via mechanical, hydraulic or inverter integrated into the motor; alternatively, it can be fixed speed via reduction geared motor.  The motorized lobe pumps can be completed with the following equipment: magneto-thermal inverter; variable-speed power transmission integrated in the motor; IP65 inverter, electric panel with IP21 inverter for automatic operation in response to filler’s remote control signal.

A roundup of B series pumps with bypass on the cover.

Wide range of seals

The shaft sealing system can be equipped with three different seals: lip seals, packing, or mechanical rotary seals. Steel, graphite, silicon or tungsten carbide, ceramics, Rulon: These are the materials to choose from according to the fluid to be pumped. The lip seal is the most economical and is ideal for low speeds and pressures, with Viton ring for products such as vegetable fats and creams, or polymer ring for chocolate, for example. The balanced mechanical rotary seal is the most popular.

This hygienic-sanitary seal does not need adjustment and maintenance except the classic replacement in case of wear. Pump seals used for the transfer of products which in contact with air crystallize or leave solid deposits, shall be flushed with water or compatible liquid at low pressure. Flushing is also useful to prevent the sliding faces from working dry (vacuum operation, for example). When a polluting or dangerous fluid is used for flushing, or if its pressure is higher than that of process fluids, the pump may be made of double mechanical flushed seals that prevent any leakage.