For applications in the food industry, all pressurized, wetted materials are FDA compliant, conform to USP class VI and are designed in accordance with the EHEDG design guidelines. 1.4435 stainless steel is the ideal choice for most requirements specified by EHEDG. The pump heads made of this material are designed to withstand pressures of up to 20 bar or liquid temperatures of 80 °C. As the more cost-effective alternative, polypropylene (PP) is ideal for use when temperature and pressure requirements are not too high. The pump head is made of PP or electropolished stainless steel with a surface roughness of < 0.5 µm in the hygienic variant. This makes cleaning the surfaces that come in contact with the product easier. Insert rings made of different materials are available for the stainless steel pump head valve seats. The valves themselves are also selected to match the fluid.
Metering accuracy of ± 1 percent and easy cleanability
The metered flow can be adjusted using the stroke length as well as the frequency of a inverter. Costly optimization and parameterization efforts are not necessary because inverters and pumps are shipped after being tested for functionality. Metering is extremely accurate at ±1 percent of precision. Different requirements profiles supplied by the customer can be implemented and the adjustment range can be expanded to a ratio of over 1:50 when using a servomotor and an intelligent control system during activation. The geometry of the pump head is designed so that residue from process media is reduced to a minimum. This also makes it possible to clean (CIP) or sterilize (SIP) the device easily on-site. The pump head's clearance space-optimized design keeps the amount of process fluid in the working area low. Additionally, the rinsing, emptying and drying processes can be carried out easily.
Compact series for sensitive and shear-sensitive products
Furthermore, a double screw spindle pump from Pomac will be exhibited. This pump is characterized by its high levels of pressure stability and is especially suitable for products with entrained solids. It can be used up to 16 bar in temperatures of 135°C and can be operated at very high speeds of up to 3,600 U/min. This series is particularly suitable for sensitive and shear-sensitive products as the screws do not touch. Instead, the product is pushed forward through the screw thread without pulsation. Every pump size can be mounted using two different screws. The free ball passage can be up to 30 mm depending on the type and enables media with large differences in viscosity to be conveyed equally. The models are quite compact and do not require an elastomer as a stator compared to progressive cavity pumps. This eliminates abrasion problems during linear pressing with the rotor and requires an extensive replacement of or change to the elastomer.
Transparent pump head makes the motion of fluid visible
Visitors to the Hannover Messe can also visit a pulsation-cavitation demonstration stand where the various operating states of a diaphragm metering pump can be displayed. This includes the behavior with low suction pressure and the influence of pulsation dampers and different pipeline designs. As a result of the M 900 pump head made of plexiglass, the working principles of a Lewa ecoflow diaphragm metering pump can be followed along live. This results in valuable information for the correct installation. The hydraulically actuated Lewa ecosmart is also equipped with a transparent pump head for illustration purposes. The diaphragm metering pump ensures maximum safety and the lowest life cycle costs in the production process thanks to reliable operation.
For conversations or specific inquiries, the Lewa team will be available in Hall 15 at the Pumpe DE joint stand in the PUMP PLAZA.