Hygienic Sanitary Centrifugal Pump for Cordial Transfer in a Liquid Filling Machine

For our latest case study we’re discussing a commission we carried out for a manufacturer of liquid filling machines. They contacted North Ridge and told us they were looking for a robust pump of a proven hygienic design. This was to be used for batch filling small cartons of squash or cordial on their liquid filling machines.  

So what is a filling machine? 

A filling machine or liquid dispensing machine is a device for filling containers, such as bottles or jars with a measured amount of liquid in an accurate, repeatable way. 

Liquid filling machines are used for a wide range of products including liquids for human consumption such as milk, water, cordial, carbonated drinks, edible oils, medicinal syrups, e-liquids and alcoholic beverages. Filling machines can be used for any quantity of production, ranging from just a few jars of liquid right up to full-scale production of thousands – or tens of thousands – of bottles.  

There are a wide range of liquid dispensing machines available, each one designed and manufactured to suit a different type of production, with filling method, fill volume, liquid type and viscosity in mind. Liquid bottle filling machines are used across a broad spread of industries, from pharmaceuticals, food and cosmetics to solvents and paints.  

How do they work? 

Liquid filling machines usually draw liquid from a large container such as an intermediate bulk container (IBC) tank, a hopper, mixing vessel or something similar. They then dispense a fixed quantity of the liquid via a nozzle into bottles, jars or other containers passing underneath on a conveyor belt. Variable speed and height-adjustable nozzles can be set to suit different types of bottles. 

These machines come in a number of options with different mechanisms, and can be manual, semi or fully automatic in operation. Smaller scale liquid filling machines are often either manually operated via a hand lever, or semi-automatic powered by compressed air, electricity or a combination of the two. 

These days, advanced technology enables automatic liquid bottle dispensing machines to give maximum productivity, durability and reliability for long periods.  

What makes a pump hygienic? 

Our client wanted a hygienic pump - but what makes a pump hygienic? There are many features that define a hygienic pump depending on the application and type of fluid that’s being pumped.  

For example, some fluids being pumped are then going to be cooked or heated up. These pumps will need different hygiene standards to pumps used to pump liquids for direct human consumption or for pharmaceutical applications such as eye solutions, where bacteria must be kept to an absolute minimum. These will demand the very highest hygiene standards. 

What are these hygienic features? 

Polishing  
 

Polishing of pumps makes absolutely sure that there’s no roughness, debris or dead zones where bacteria can gather and multiply, or where particles could come loose potentially contaminating future batches. Hygienic pumps are highly polished to ensure that the surface level is less than 0.5mm microns. This makes them easy to clean especially using CIP and SIP processes. 

CIP is short for Clean-In-Place, a cleaning method which enables the internal surfaces of sealed systems to be cleaned, without removing or disassembling piping or equipment to carry out the cleaning. 

SIP is Sterilisation-In-Place which extends the CIP process by adding sterilisation, without any need for disassembling the liquid dispensing machine, piping or measuring equipment. This takes place at the end of CIP and ensures that any microorganisms still active in the system are killed off with hot water, or with saturated pure steam at high temperatures of over 121°C. 

Materials 

Most stainless steel ordered around the world is Grade 304, as it offers the standard corrosion resistance, formability, strength and easy maintenance for which stainless steel is renowned. Grade 316 may be second in amount sold, but it offers vastly superior corrosion resistance to chlorides and acids.  

Grade 304 is certainly a minimum requisite for a hygienic pump. It also provides strong resistance against acids or alkalis which may be present in the liquid, or may be used in a caustic Cleaning-in-Place regime.  

Occasionally, cast iron is used in chocolate pumping as bacteria don’t multiply within chocolate. In addition, pumps containing cast iron can be effectively used with magnetic separators which detect and capture any metal present in pumped fluids.  

Cowl and feet 

A cowl is fitted over a pump motor for two key reasons. Firstly, it stops debris, dust or other matter collecting between the motor fins, making cleaning difficult and creating a health hazard. It also means that the pump can be easily cleaned by jet washing during wash-down. While fitting feet to the pump keeps the pump head away from the floor, stopping debris getting in if the pump head is opened for inspection. 

Connections 

Where pipework is present in a process, it’s very important to ensure that all connections are sanitisable and stop the build-up of debris. Sometimes, fittings like tri-clamps are used which can be polished, are easily cleanable and have full pass-through preventing the accumulation of debris. 

Pumps can be fitted with a variety of socketed pipework connections from North Ridge Pumps with a range of features and hygiene ratings. Certain types of fitting may be hygienic, but if they are not designed to accept Clean-in-Place, the pump must be disassembled and cleaned manually to maintain an effective hygiene programme. 

Suitable for CIP 

As mentioned, Clean-in-Place describes specific systems and equipment used in food processing that can be cleaned and sanitised without being disassembled or moved. Whether it’s down to a dedicated CIP/SIP port or through hygienic design, this feature ensures that the pumps can be sanitised, either via a caustic or acid wash to remove debris and bacteria. 

Third-party approved gaskets or seals 

These ensure that when certain materials are used for hygienic seals and sanitary gaskets, the food or beverages which are being pumped are not contaminated during contact and have the highest levels of hygiene. Standard hygienic materials include Silicone, Neoprene, Nitrile (NBRA), EPDM, Norprene, Tygon, Viton (FKM) or Virgin PTFE/TEFLON.  

Typical certification bodies include the European Hygienic Engineering and Design Group and the Water Regulations Approval Scheme in Europe, and the Food and Drug Administration, National Sanitation Foundation 61 and 3-A Sanitary Standards in the US. 

Hygienic pumps for the food and beverage industry  

Clearly, with products made for direct human consumption, this sector needs hygienic pumps when transferring a variety of liquids or high value flavourings and colourings.   

What’s more, when beverages like concentrate, juices, cordials, wine, spirits, beer, tea and coffee are transferred they need specific pump features to make sure that the liquid doesn’t froth, is transferred hygienically and doesn’t change in any way.   

We have a great deal of experience transferring these kinds of liquids and have a range of pumps with essential features: 

• Easy to clean and sterilise, with full hygiene accreditation and compatibility with CIP cleaning programmes 

• Hygienic rated and suitable for liquids designed for human consumption without contamination 

• Tailored seal designs depending on the liquid being pumped, to boost seal longevity and avoid crystallisation on the seals 

• Flexibility to enable easy use with a selection of liquids and processes 

• Variable speed to give simple speed adjustment between processes 

• Low speed pumps to prevent frothing or any changes to the liquid 

• ATEX rated for the handling of flammable alcohols 

• Minimal wastage of liquids which may be particularly expensive – we have pumps which can extract up to 99.98% of the contents 

A pump specially designed for the food industry 

At North Ridge Pumps, we’re not restricted to just one pump technology, so we can specify the right pump for any application - at the lowest lifetime cost. In fact, we use our expertise to offer a bespoke solution, not something picked off the shelf. 

For this specific project, we specified one of our sanitary centrifugal pumps. This entire range has been specifically developed by our design engineers for the pharmaceutical, cosmetic, food and beverage industries.  

All of these pumps are approved by both the US Food and the Drug Administration, and by the European Hygienic Engineering and Design Group. This is a consortium of food producers, equipment manufacturers, institutes and universities who have come together to enhance food safety and quality across the whole industry.  

These accreditations mean that both the construction materials and the pump design meet the highest US and European hygienic standards and regulations.  

Fully hygienic construction 

Thanks to their fully hygienic inner design, these food-grade sanitary centrifugal pumps can be completely sanitised by either Clean-In-Place or Sterilisation-In-Place processes. As mentioned, this means that no disassembly is needed to clean the pump’s internal components, making day-to-day maintenance quicker and easier, and reducing downtime enormously. 

What’s more, this range is highly efficient as they consume much less power than other hygienic centrifugal pumps. Moreover, the impeller at the heart of these pumps is also very efficient, and as a result the Net Positive Suction Head (NPSH) needed for this range is lower than usual, greatly reducing the risk of cavitation.  

ATEX-rated motors for flammable alcohols 

In addition, our sanitary centrifugal pumps can be fitted with ATEX-rated, explosion-proof motors. These are usually specified for hazardous or explosive environments, and for transferring highly flammable liquids such as ethanol, butanol, methanol and any alcoholic spirits. 

These pumps are available with the full range of hygienic connections and fittings we offer, including DIN 11851, DIN 11861, RJT, SMS, tri-clamps and more. There are also a number of accessories and additional features available including double mechanical seals with thermo-syphon cooling, a heating chamber on the pump body, Variable Frequency Drive and a trolley mounting for the pump. 

If you have a process you’re looking to achieve and would like some support and guidance from our design engineers, talk to North Ridge Pumps today to see how we can help. 

For more information on Hygienic Sanitary Centrifugal Pump for Cordial Transfer in a Liquid Filling Machine talk to North Ridge Pumps Ltd