Valve homogeniser

Recently, these sampUng problems have been addressed in the development of an FTIR method for the determination of fat and protein in raw meat [32]. The use of a custom-designed high-pressure valve homogenise was found to ehminate the requirement for filtration of meat suspensions prior to IR analysis. The homogenates obtained were injected directly into a heated (65°C) flow-through transmission cell, with a 0.037-mm pathlength. The accuracy and reproducibility of the FTIR method were reported to be superior to those of the reference chemical methods... 

Only a selection of commercially available mixing equipment has been described here. Indeed, the devices described all exist in a variety of configurations. In a ition, there are many items of equipment based on altogether different principles typical examples include jet mixers, in-line dynamic mixers, mills, valve homogenisers, ultrasonic homogenisers, etc. These, as well as many other types, have been discussed by Harnby et alp-K Oldshue and Nagata ... 

Liquid foodstuffs, for example milk products must be submitted to homogenisation treatment in order to improve their long-term physical stability ("shelf life"). The liquid is pumped at very high pressure by a multiplex reciprocating piston pump through the narrow clearances of a hydraulically controlled homogenisation valve (Fig. 1.4-4, C, bottom). 

Homogenisation processes now extend up to 1500 bar differential pressures. As the materials to be homogenized exhibit varying properties with respect to viscosity, corrosiveness and abrasiveness the high pressure components, such as homogenising pumps and valves, need very careful design and choice of materials. 

Whiteley, A.J., and Muir, D.D. (1996). Heat stability of homogenised concentrated milk. 1. Comparison of microfluidiser with a valve homogenizer. Milchwissenschaft 51, 320-323. 

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