Spiral mixer process

The spiral mixer process is sometimes called the continental no time process because these mixers originated in continental Europe where small bakers are much more common. Neither L-cysteine nor potassium bromate are needed. The only flour treatment needed is ascorbic acid. 

In batch processing, the various additives are mixed with the prepolymer component in a jacketed horizontal (Z-blade) or vertical (helicone or spiral) mixer. Prior to this, however, a high-speed liquid mixer is used to dis-... 

When potassium bromate was struck off the UK permitted list in 1990 the ADD process was no longer viable. Unsuccessful attempts were made to use ascorbic acid with or without azodicarbonamide. ADD then is only a viable method where potassium bromate is allowed. As the continued use of potassium bromate comes under further pressure then scope for using the ADD method decreases. Those bakers who had used ADD almost certainly did not go to the bulk fermentation process but moved to using a spiral mixer. 

A further development from ADD methods is the use of spiral mixers by small bakers. These machines put energy into the dough less rapidly than the sort of mixer used in the Chorleywood process but a spiral mixer is less expensive and more versatile. The actual dough development time will always depend on the recipe, the flour improver and the flour but, for comparison, while a Chorleywood mixer will develop a dough in 2-5 min a spiral mixer will take 8-15 min. 

Spheripol, Process for producing polypropylene, Montell North America Spinner, Locking ring valve, Zeiger Industries Spiral Mixer, Motionless static mixer, TAH Industries, Inc. 

Convection. In these mixers an impeller operates within a static shell and particles are moved from one location to another within the bulk. bbon Tjpe. Spiral or other blade styles transfer materials from one end to the other or from both ends to the center for discharge (Fig. 37b). This mixer can be used for dry materials or pastes of heavy consistency. It can be jacketed for heating or cooling. Blades can be smoothly contoured and highly pohshed when cleanliness is an important process requirement. 

Some of the more widely used high-performance screws include the Energy Transfer (ET) screw [19], the Variable Barrier Energy Transfer (VBET) screw [20], the Double Wave screw [21], Stratablend [22] and Stratablend II [23] screws, and the Unimix [24] screw. Other devices can, however, act as a trap for solid materials from the melting section. These devices include Maddock-style mixers [25], spiral dams, and blisters. They will be briefly discussed in this section as many of them have been the subject of many articles on secondary mixing processes. 

In addition, Chandavimol et al. (1991a,b) have estimated the kinetic rate at which the bubbles go from initial size to the maximum equilibrium size as a function of energy dissipation. The rate of dispersion was found to be approximately proportional to energy dissipation rate. [See Figure 7-24 for a comparison of bubble breakup rate between vortex (HEV) and spiral (KMS type) static mixers.] In general, the equilibrium drop size is reached in a few pipe diameters. However, the drop size distribution is narrowed as the simultaneous processes of drop breakup and coalescence are continued, depending on the mixer design and fluid properties. See also Hesketh et al. (1987, 1991). 

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