Seal solution sustains pump reliability for dairy firm

The Them dairy is a cooperative organic dairy in Denmark, specialising in the production of speciality craftsman cheeses along with other dairy products.

Founded in 1888 by local farmers, the cooperative has grown to include 27 members today and produces approximately 6,000 tons of cheese annually.

Them dairy prides itself on modern production and has been named a National Champion of Environmental and Corporate Sustainability in the European Business Awards.

Cheese production presents a number of challenges when considering pump reliability in an environment which demands the highest standards of hygiene.

During the production process, clean in place (CIP) fluid picks up raw cheese and liquids from the equipment that it cleans, which migrate into the seal barrier fluid. This is extremely damaging to the seal faces and swiftly results in seal failure. It also, in turn, causes leakage which is costly in terms of product loss, the operational downtime required for maintenance, and frequent replacement of the seals.

To minimise the risk of contamination by the dairy foodstuffs being processed, and maximise pump reliability, seal faces are constantly flushed with large volumes of clean water, which is then discarded. This ‘quench to drain’ process is both costly and environmentally unsound.

Cleanliness is critical to the food processing environment, but the seal support vessels traditionally used to circulate the flow of water are difficult to inspect and clean and can harbour bacteria on the sealed interior, presenting a real threat of product loss due to contamination.

Them dairy had 20 CIP return pumps which were fitted with original equipment manufacturer (OEM) double component seals and a quench to drain support system. Seal life was extremely short – as little as three months - due to the damaging impact of dairy products migrating into the barrier fluid as a result of the CIP process.

The mean time between failure (MTBF) for the mechanical seals increased from as little as three months to three years

The huge volumes of water needed to constantly flush the seal faces was also of particular concern to a company with a strong sustainability ethos. It calculated that 20 pumps running on average for eight hours a day, 260 days a year, were consuming 1.2 million litres of flush water every year. The risk of contamination posed by the sealed support vessel was also a critical consideration.

The solution

AESSEAL replaced each pump’s OEM mechanical seals with dual cartridge mechanical seals, and the traditional support vessel with an SW2 EasyClean water management system, which continuously recycles the flush water, eliminating waste.

The mechanical seals are fully retrofittable, so no pump modifications were needed, and installation was quick, easy and cost-efficient.

Developed specifically for industries requiring exceptional standards of hygiene, the EasyClean water management system offers the water saving elements of the most advanced seal support systems, whilst also maximising cleanliness and protecting product quality.

It has a detachable lower section with a quick-release clamp, so it can be easily removed to inspect the chamber for signs of bacteria and carry out cleaning. Its interior also has filler welds to plug any crevices and gaps which might otherwise become bacteria traps.

The upgrade from a quench to drain system to SW2 EasyClean water management system saw seal water usage at Them dairy reduced by 99.7%.

The mean time between failure (MTBF) for the mechanical seals increased from as little as three months to three years. Tests for potential contamination of the seal barrier fluid several weeks after fitting showed that no cheese-contaminated CIP fluid had migrated into it. The mechanical seals require minimal maintenance.

The ease of inspecting and cleaning the seal support system means Them dairy is confident that bacterial contamination is no longer a risk. Savings have been achieved through reduced downtime and lower maintenance costs.

Them Dairy CEO Torben Aarris said: “We’ve had excellent cooperation with AESSEAL Denmark to bring about these important improvements to our cheese production processes.

“As a cooperative with a strong commitment to community, organic production and the environment, we’re particularly pleased to play our part in vital water conservation.

“We also have even greater confidence in maintaining exceptional standards of hygiene.”