Hygienic pumps for the food industry
Where can hygienic pumps be used?
Hygienic pumps are used wherever it is necessary to pump sensitive products that must not be contaminated by germs or residues. This is particularly the case in the food and beverage industry. However, pharmaceutical processes and specialized industrial applications also require hygienic pumps.
High Requirements for Processes and Materials
Hygienic pumps must meet specific requirements regarding materials, surface quality, and cleanability. The terminology used is not standardized. While the term “hygienic pumps” is used in Europe, the term “sanitary pumps” is used in the United States. The parallel use of these terms is not accepted.
Certificates and Material Certificates
Organizations such as EHEDG or 3A Sanitary Standards Inc. evaluate hygienic pumps and other equipment for their suitability. EHEDG and 3A certificates are therefore an indicator of the proper design and construction of hygienic pumps. The approaches taken by these organizations differ. EHEDG certifications are based on empirical findings from testing, while 3A certifications are based on a detailed analysis of the design documentation. Hygienic pumps are typically manufactured from 1.4404 (316L) stainless steel. For aggressive media, higher-grade stainless steels such as 1.4539 or duplex grades are also used.
Hygienic Design and CIP
Hygienic pumps must be cleaned at regular intervals. This is typically done while the pump is installed in the system. In this case, the process is referred to as CIP cleaning, where CIP stands for “cleaning in place.”
Cleaning is performed using high-temperature alkalis and acids, as well as a rinse solution, which is circulated through the system in large volumes to achieve the minimum flow rates required for thorough cleaning. All components must be accessible. The pumps must therefore be designed free of dead spaces. HYGHSPIN twin screw pumps offer a particular advantage when it comes to cleaning. Not only are they free of dead spaces and thus suitable for CIP cleaning, but they can also be used as CIP transfer pumps themselves. This eliminates the need for additional CIP pumps, changeover valves, and control systems. As a result, costs and the risk of system malfunctions are reduced.
A Reliable Process Thanks to High Surface Quality
The goal of a hygienic pump is to ensure that the pumped media are not contaminated during transport. Therefore, care is taken to ensure, on the one hand, that residues are as unlikely as possible to adhere to the pump and, on the other hand, that they can be removed as easily and thoroughly as possible. Hygienic pumps feature a high surface quality. Typically, surface roughness is approximately 0.8 µm.
For particularly sensitive products in the pharmaceutical industry, even higher standards are required, with surface roughness values of less than 0.4 µm. The smooth surfaces make it difficult for deposits to form and facilitate cleaning.
| Technical parameters Sizes | ||||||
| Typ | HYGHSPIN 50 | HYGHSPIN 70 | HYGHSPIN 90 | HYGHSPIN 105 | HYGHSPIN 125 | |
|---|---|---|---|---|---|---|
| Max. flow rate | 20 m³/h | 40 m³/h | 100 m³/h | 180 m³/h | 300 m³/h | |
| Max. delivery pressure | 20 bar | 25 bar | 30 bar | 20 bar | 35 bar | |
| Max. ø solids | 16 (25) mm | 20 (30) mm | 28 (45) mm | 35 mm | 45 (67) mm | |
| General specifications | ||||||
| Suction capability | NPSHr > 0.5 m, suction heads up to 9 m possible | |||||
| Viscosity | 0.5–1,000,000 mPa s, higher values upon consultation | |||||
| Pumping temperature | –10 to 180 °C, higher values on request | |||||
| Cleaning | Fully CIP-cleanable in the system | |||||
| Sterilization | SIP in the system with steam or hot water | |||||
| Parts in contact with the product | 1.4404, 1.4539, or 1.4462 as an option, other materials on request | |||||
| Elastomers | HNBR, FPM, EPDM, FFPM, FDA approval, other elastomers on request | |||||
| Shaft seals | Single- and double-acting mechanical seals, with knife edge for sticky media to prevent start-up damage, dry-run-safe single-acting lip seal | |||||
| Pump orientation | horizontal, vertical, or sideway, INLINE versions possible | |||||
| Connections | Various sizes and connection standards upon agreement | |||||
| Design | Compact, robust modular design for all sizes, with free shaft end for sizes 50, 70, 90, 105, and 125 | |||||
| Drives | Three-phase, gear or servo motors (hygienic drives in stainless steel design as an option) | |||||
Static Seal and SIP
There are many details to consider when it comes to hygienic pumps. For example, certified materials suitable for the elastomers must be used, and thermal expansion must be taken into account. In HYGHSPIN twin screw pumps, molded rings are used for static seals to prevent product entrapment in grooves due to thermal expansion.
In addition to cleaning, hygienic pumps for aseptic applications are regularly sterilized within the system. This process is referred to as SIP (sterilisation in place). Superheated steam at temperatures ranging from 130°C to 145°C kills germs and ensures an aseptic state.
