Operating Principle

The Niro VHP homogenizer consists of a horizontal single acting reciprocating multi plunger pump (single plunger for table top lab units) with a homogenizing valve installed on the high-pressure outlet manifold. The homogenizer pump operates at a near constant flow rate regardless of the homogenizing valve set-pressure (back-pressure to the pump).

Homogenizing valve

The homogenizing valve consists of three main components - the impact head, impact ring and passage head. Homogenizing pressure is increased when pressure is applied by the pneumatic actuator to the valve shaft, closing the adjustable gap (flow area) between the impact head and the passage head. The homogenizing effect is caused by the product entering the valve inlet at pressure, as it passes through the minute gap the velocity rapidly increases while the pressure rapidly decreases to atmospheric. The product is subject to shear / impingement as it is forced through the valve then impact as it hits the impact ring at high velocity, the intense energy change also causes turbulence and cavitation.

Reciprocating multi plunger pump

The homogenizing efficiency is due to a combination of the pressure applied and the geometry of the valve. There are different valve geometries available depending on the application, whether you are trying to obtain a stable emulsion, particle size reduction of a suspension or cell rupture. The Niro R type sharp profile valve design is a result of fluid dynamic calculations, R&D testing and experience gained in the field. The Niro Soavi R type valve requires substantially less pressure than flat profile valves or alternative homogenizing technologies to achieve the same degree of particle size reduction or cell rupture.

Impact ring, valve, and impact head

GEA Niro Soavi VHP systems can also be equipped with a second stage homogenizing valve for emulsion applications. The second stage valve is placed in series with the first stage valve and is used to break up clusters in nano emulsions which can result from particle size reduction after the first stage, this is particularly important for intravenous applications.

VHP Design Features

• Up to 21,750 PSIG continuous operating pressure.
• Minimum batch volume - 50 ml.
• VHP homogenizer units available for product flow ranges from 10 - 5,000 LPH.
• Standard homogenizer systems available for product flow ranges from 80 - 1,200 LPH, optional systems available down to 10 LPH and up to 5000 LPH.
• High efficiency ceramic sharp profile dynamic homogenizing valve with pneumatic pressure control which includes dampening to maintain a constant homogenizing pressure.
• Aseptic flush double plunger seal arrangement with FDA compliant UHMW-PE packing.
• Multi block homogenizer compression head which eliminates stress concentration points and minimizes dead-legs allowing optimal drain-ability, designed for both CIP and SIP.
• The homogenizer compression head has non shedding components and parts due to material selection and design.
• Product contact materials are FDA compliant and are AISI 316L or better.
• Meets the ASME BPE requirements for cell disruptors.
• Table top lab through to production scale machines have the same valve geometry and operating principle with proven scale-up ability.

Product Contact Materials

• ASTM S32750 high alloy duplex stainless steel compression head.
• EPDM O-rings complying with FDA requirements
• Solid ceramic (99.7% Al2O3) plungers and homogenizing valve components - impact head, ring and valve seat, complying with FDA requirements.
• Optional C9M grade tungsten carbide homogenizing valve components available - FDA compliant.
• UHMW-PE plunger packing with PEEK anti-extrusion ring - FDA compliant.
• Stellite alloy 20 compression head pumping valves - FDA compliant.
• Product contact surfaces < 20 Ra (µ-inch) + electropolish.

VHP Compression Head