New Tweedy Mixer with Cleaning, Maintenance and Operational Upgrades
The Baker Perkins range of Tweedy bread dough mixing systems has been extensively re-engineered for more hygienic operation, easier maintenance and lower noise levels. These significant cleaning, maintenance and operational upgrades were achieved while retaining all the important process characteristics which ensure high-quality dough at high outputs.
Improved hygiene has been addressed in two ways: reducing the levels of dust, water and dough debris and completely removing debris that accumulates.
A major development is the introduction of a wash-in-place system for the mixing bowl and lid, replacing manual cleaning. Water is fed to pressure jets via a retractable hose within the bowl, fitted to the beater by the operator whenever cleaning is required. A 75mm self-cleaning valve ensures the bowl drains completely with no dough leftovers. The exterior of the bowl and the swing frame can be washed down with a hose.
Cleaning and maintaining the lid is much easier. The ingredient feeding and the lid clamping arrangement have been simplified to reduce the number of entry ports. All liquid ingredients are blended in a manifold with the water and fed to the mixer bowl through a single inlet; the actuators for the lid clamps are underneath the bowl covers. The ingredients platform has also been moved closer to the bowl for easier access to the lid.
All liquid ingredient tanks and vessels are now mounted above a drained section of floor on the ingredients platform, so any leaks or spills go straight to the drain. This also allows a hose-down of the platform.
As far as maintenance is concerned, the simplified arrangement of components and associated pipe-work and cables means better access and easier tasks. Calibration routines are also much quicker and simpler.
The pressure vacuum pump has been designed for quieter operation and is mounted on a skid that can be located in a separate room or soundproof enclosure.
Noise from the main drive is reduced by using a high performance belt with reduced contact area, while the motor and bowl sit in machined locations on the swing frame to ensure they are perfectly aligned. The main drive motor chamber is fully sealed against noise and dust with easily removable covers providing good access for maintenance and cleaning.
The new mixer design has been assessed with respect to ATEX compliance and specific zones have been designated where necessary. This means that it will remain compliant as long as the equipment is cleaned and maintained correctly.
The benefits of advanced hygiene and maintenance have been achieved while retaining key features, including the beater and bowl configuration, height-to-diameter ratio, pressure/vacuum mixing, and mixing to energy input.
Baker Perkins consulted bakers throughout the world to ensure that the new Tweedy mixer exceeds the demands of today’s environmental and safety requirements. Tweedy integrated mixing systems are widely used for the complete range of pan and tin bread doughs including white, brown, wholemeal, multigrain and mixed rye loaves.
They also handle a full selection of doughs for artisan and country style hearth breads, as well as buns, pizza, pastries and cakes.
Tweedy mixers are fully automated from ingredient feed to delivery to the divider at outputs up to 5,400kg per hour. Flexibility for small to medium sized bakeries is provided by smallest model in the Tweedy range, the T170, with batch sizes from 85kg.