Marmite project saves time and energy
1 Oct 2007
Unilever UK has increased throughput by 30%, made waste savings of 10% and cut energy consumption by a third following an overhaul at its Marmite/Bovril plant in Burton-upon-Trent. The multi-million pound project featured the installation 16 new vessels — alongside eight existing tanks — for storing processed brewer's yeast, backed by new valve technology.
The basic raw material used in the manufacture of Marmite is spent brewer's yeast. The product enters the factory as a brewer's yeast slurry from which the cell content is first separated and then concentrated in an evaporator before being transported to the storage vessels. The mixture then undergoes further filtration and evaporation stages.
Throughout the process, one tank is being filled, another is being emptied and a third is being cleaned using a CIP system built around rotary spray heads installed in each tank.
Unilever's engineers had considered replacing the original manually-operated valves with sanitary butterfly valves but eventually opted for Alfa Laval's Unique Mixproof valves. These units are designed to enable two incompatible media to flow through the system without intermixing and can isolate the product and CIP streams in the Marmite production process.
Flow of product and CIP fluids between the tanks and other key elements in the production process is controlled by the new valves and ThinkTop valve control units — also from Alfa Laval.
In combination with a central processor, the units have automated the whole process of filling, emptying and cleaning the tanks. The vessels and process areas previously had to be isolated manually before carrying out these operations.
Controlled remotely using compressed air, each Unique Mixproof valve is normally closed with two plug seals forming a leakage chamber between them. When the valve is opened, the leakage chamber is closed enabling product to flow from one line into the other. Any accidental leakage flows into the chamber.
The SeatClean versions of the valve installed at the Marmite factory enable the plugs and valve seat to be cleaned via seat lift during normal CIP operations. The valve also incorporates a balanced lower plug that absorbs pressure shocks or constant high pressures to prevent leakage and product mixing.
The new valve control and indication unit employs a no-touch system, which makes mechanical sensor adjustments unnecessary and ensures accuracy and repeatability. Chips built into the sensor unit detect the axial magnetic field of a magnet mounted on the valve stem and, by measuring the angle from each chip, the unit is able to calculate the precise position of the valve stem at any time.
LEDs on the unit, meanwhile, provide a constant display of valve position, solenoids activated, set-up and instant fault indication.
The basic raw material used in the manufacture of Marmite is spent brewer's yeast. The product enters the factory as a brewer's yeast slurry from which the cell content is first separated and then concentrated in an evaporator before being transported to the storage vessels. The mixture then undergoes further filtration and evaporation stages.
Throughout the process, one tank is being filled, another is being emptied and a third is being cleaned using a CIP system built around rotary spray heads installed in each tank.
Unilever's engineers had considered replacing the original manually-operated valves with sanitary butterfly valves but eventually opted for Alfa Laval's Unique Mixproof valves. These units are designed to enable two incompatible media to flow through the system without intermixing and can isolate the product and CIP streams in the Marmite production process.
Flow of product and CIP fluids between the tanks and other key elements in the production process is controlled by the new valves and ThinkTop valve control units — also from Alfa Laval.
In combination with a central processor, the units have automated the whole process of filling, emptying and cleaning the tanks. The vessels and process areas previously had to be isolated manually before carrying out these operations.
Controlled remotely using compressed air, each Unique Mixproof valve is normally closed with two plug seals forming a leakage chamber between them. When the valve is opened, the leakage chamber is closed enabling product to flow from one line into the other. Any accidental leakage flows into the chamber.
The SeatClean versions of the valve installed at the Marmite factory enable the plugs and valve seat to be cleaned via seat lift during normal CIP operations. The valve also incorporates a balanced lower plug that absorbs pressure shocks or constant high pressures to prevent leakage and product mixing.
The new valve control and indication unit employs a no-touch system, which makes mechanical sensor adjustments unnecessary and ensures accuracy and repeatability. Chips built into the sensor unit detect the axial magnetic field of a magnet mounted on the valve stem and, by measuring the angle from each chip, the unit is able to calculate the precise position of the valve stem at any time.
LEDs on the unit, meanwhile, provide a constant display of valve position, solenoids activated, set-up and instant fault indication.
