this mesh, approximately two thirds is conveyed back by auger or bel sh plus 1. 5mm mesh-is removed. Of the finer material which asses eed powder to meet up with the cooked potatoes in the first mixing process The proportion fed back must be carefully metered to provide exactly the correct proportion in relation to the quantity of potatoes passing through the cooking stage. As explained before, this proportion will be of the order of 65 percent The remainder of the powder, having passed through the screen, passes to a secondary dryer, which ideally is(a)a fluidised bed dryer, or(b) a rotary louvre dryer. This secondary drying reduces the powder to 6-7 percent moisture content. The secondary dryer discharges into a collecting cyclone and it is customary to locate the latter in a cooling system. An air ring, similar in design to the ring dryer, but utilising cold air, is ideal for this purpose, and this cools the product down to about 16C. From the cold air cyclone, the powder discharges through a rotary valve on to a final screen fitted with a 250 micron stainless steel sieve, and the'through' material is the final product which then goes to pack-off.Any overtails from the final screening are returned back as seed. It is essential that a permanent cascade magnet be fitted on the outlet of the last screen,to remove any ferrous metal contamination. A Finex 22 sieve with 2 decks as illustrated is ideal for this purpose, and a Finex 48 sieve for the initial a3eono, rom the foregoing description, it is seen that the process involvesthe continuous feeding back of part of the dried material, which is used to sorb in excess of 50 percent of the initial water content of the cooked potato. The processor must therefore, always retain a stock of seed granules to start up the system at the beginning of a new season. It must also be remembered that the rate of pack-off of the final powder can only equate ith the input of raw potatoes, and if this is wrongly estimated, the seed will gradually bleed out of the system, and the process will eventually come to a halt. This balance can only be achieved with experience, and the constant attention of the dryer operative Product should be packed in nitrogen-flushed drums for prolonged storage, or 25kg polyethylene-lined sacks for 6-8 weeks storage in temperate conditions RATIO Expected ratio of final product at 6 percent moisture content, using potatoes with 20 percent solids, would be expressed as about 6: 1- plus 1.5mm mesh - is removed. Of the finer material which passes through this mesh, approximately two thirds is conveyed back by auger or belt as seed powder to meet up with the cooked potatoes in the first mixing process. The proportion fed back must be carefully metered to provide exactly the comt proportion in relation to the quantity of potatoes passing through the cooking stage. As explained before, this proportion will be of the order of 65 percent. The remainder of the powder, having passed through the screen, now passes to a secondary dryer, which ideally is (a) a fluidised bed dryer, or (b) a rotary louvre dryer. This secondary drying reduces the powder to 6-7 percent moisture content. The secondary dryer discharges into a collecting cyclone and it is customary to locate the latter in a cooling system. An air ring, similar in design to the ring dryer, but utilising cold air, is ideal for this purpose, and this cools the product down to about 16°C. From the cold air cyclone, the powder discharges through a rotary valve on to a final screen fitted with a 250 micron stainless steel sieve, and the 'through' material is the final product which then goes to pack-off. Any overtails from the final screening are returned back as seed. It is essential that a permanent cascade magnet be fitted on the outlet of the last screen, to remove any ferrous metal contamination. A Finex 22 sieve with 2 decks as illustrated is ideal for this purpose, and a Finex 48 sieve for the initial screening. From the foregoing description, it is seen that the process involves the continuous feeding back of part of the dried material, which is used to absorb in excess of 50 percent of the initial water content of the cooked potato. The processor must therefore, always retain a stock of seed granules to start up the system at the beginning of a new season. It must also be remembered that the rate of pack-off of the final powder can only equate with the input of raw potatoes, and if this is wrongly estimated, the seed will gradually bleed out of the system, and the process will eventually come to a halt. This balance can only be achieved with experience, and the constant attention of the dryer operative. Product should be packed in nitrogen-flushed drums for prolonged storage, or 25kg polyethylene-lined sacks for 6-8 weeks storage in temperate conditions. RAT1 0 Expected ratio of final product at 6 percent moisture content, using potatoes with 20 percent solids, would be expressed as about 6:l. 111