| 摘要 |
Blood meal is produced in an entirely mechanical process in which there is pre-treatment by in-line milling (3) of received blood by a hammermill followed by continuous agitation in supply tanks. An homogenous and consistent blood supply is therefore directed to a continuous part of the process in which the blood is pre-heated to a temperature of approximately 60°C by direct injection of steam in which there is a good deal of agitation caused by injection of the steam from underneath. There is significantly more agitation of the blood in a coagulator having a relatively small diameter for a relatively high speed for the given transfer rate. During passage through the coagulator (28), steam is injected through 2 mm apertures in a screen (29) which surrounds the full internal surface of the coagulator (28). Dewatering is carried out at a decanter (32) to provide serum having a solids content of approximately 2%. This may be evaporated. A 60% solids portion referred to as crac is delivered to a disc drier which is particularly effective at drying the crac to the desired moisture content with relatively little adherence of the blood to the moving members. A cooling auger (39) has the effect of substantially cooling the meal and also of ensuring that it is of uniform particle size, before it is screened (40) to provide the desired output. Oversize particles of the screen (40) are milled in a hammermill (41) having a 3 mm screen size. |
