Abstract:
The invention relates to a method for warm dehulling soya and other bean fruits and for subsequently grinding them, as well as to corresponding installation. The invention can simplify the process and the design of the installation. To this end, the fruits and heated/conditioned, double-ground, individualized on a baffle plate and the hulls are removed.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application under 35 U.S.C. §120 of PCT/CH00/00461, designating the United States, filed 30 Aug. 2000, which is incorporated herein by reference. 
    
    
     BACKGROUND 
     The present invention relates to a process for warm dehulling soya beans and other bean fruits and subsequently grinding them, as well as an installation for carrying out said process. 
     The warm dehulling of soya or other bean fruits, for example in preparing subsequent grinding, is known in general. DE-C-3544387 describes such a dehulling process, in which the fruit are heated through to the core at a certain temperature, are next subjected to a hot gas flow followed by removal of the hulls. The fruit are heated through at 50° C. to 75° C. at least partially by means of contact heat. The temperature in the gas flow is raised to 90° C. 
     The fruit are subjected to the contact heat in a device with hot surfaces, and to the hot gas flow on the other hand in a fixed or fluidised bed. The dehulling device can be a baffle dehuller downstream of which another fluidised bed and/or a pneumatic sifter for removing hulls can be connected. Conditioning is carried out prior to grinding. 
     In a known, two-step grinding procedure, a first rough grinding step employing a pair of serrated rollers, followed by a pair of rubber rollers, is followed by a reducer and this is followed by a second rough grinding step employing two pairs of serrated rollers. 
     SUMMARY 
     The present invention is directed to a process for warm dehulling of soya bean fruits or similar fruits or products, which avoids the disadvantages of the prior art and enables the process to be carried out in a simplified manner. 
     An installation is provided for carrying out the process. A device is also provided for dehulling the fruit and removing the hulls (hull separator). 
     An exemplary process enables greater efficacy with fewer procedural steps. Conditioning and heatshock of soya or other bean fruits are followed by rough-grinding in a double-grinding unit and individualising on a baffle plate, followed by separation of the hulls with aspiration. A fine grinding procedure can follow this step. 
     The process enables a protein-rich meal (47% to 48%, depending on the protein content in the beans) to be produced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described hereinbelow in greater detail in an embodiment with reference to a diagram, in which: 
         FIG. 1  illustrates a diagram of an exemplary process of an installation for warm dehulling and grinding soya or the like, 
         FIG. 2  illustrates a cross-section of an exemplary hull separator. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the following embodiment only the essential procedural and installation components are to be described in greater detail. Other associated procedural steps and installation components will emerge naturally from  FIG. 1  with reference to the known prior art. 
     Whole soya beans enter steaming apparatus  1  and then a fixed or fluidised bed  2  for conditioning, as described for example in DE-C-3544387. The soya beans are heated in the steaming apparatus  1  by means of contact heat and in the fluidised bed  2  they are subjected to continuous heating in a hot gas flow at an average temperature of 70° C. to 90° C. On completion of heating the beans have a moisture content of 10–11%. Hulls which are already loosened are separated from the beans both in the steaming apparatus  1  and in the fluidised bed  2  in a known manner. 
     The beans prepared enter a heating receptacle, not illustrated here, (interim depot) or directly enter a rough-grinding roller frame  3 . This rough-grinding roller frame  3  contains two directly superposed roller pairs  4 ,  5  which create a double-grinding step, as described for example in EP-C-335925. The roller pairs  4 ,  5  display serrated rollers. 
     The ground beans then reach a baffle individualizer  6  and then a hull separator  7 , where the hulls are completely separated from the broken beans. The separated hulls can be subjected to further sifting in an air stream. This is then followed by a device for flaking in a flaking mill and/or continued grinding in a fine milling device. 
     Referring to  FIG. 2 , the hull separator  7  comprises a substantially cylindrical housing  701  having an upper material inlet  702  and a lower material outlet  703 , as well as a lower gas inlet  704  and an upper gas outlet  705  for passing the crushed beans through in the countercurrent. In the process the beans are not only aspirated, but all loose hulls are also carried away in the gas stream. 
     The material inlet  702  contains a delivery chute  706  via which the beans (and hulls) impact a first conical baffle  707  arranged concentrically to the delivery chute  706  in a circular manner. Loose hulls and light particles are taken away by the gas stream flowing in the opposite direction. On the other hand the bean constituents roll down the conical surface of the baffle  707  and fall into an underlying hopper  708 . Projecting into the open floor  709  of the hopper  708  is another underlying conical baffle  710 . Due to the effect of gravity the beans and hull constituents roll from hopper  708  onto the conical surface of the second baffle  710  and from there into the other underlying hopper  711 . In the process other hull constituents can be removed with the gas flow. 
     Projecting underneath this hopper  711  into the floor  712  of the second hopper  711  is another such baffle  713 . A third and fourth baffle follow in a similar manner. The fourth baffle  713  has a similar hopper with an open floor  714 . A fifth conical baffle  715  protrudes into this floor  714 , as described hereinabove. This displays beneath its conical surface a cylindrical jacket surface  716 , such that this baffle  715  covers the concentrically arranged opening  717  of the gas inlet  704 . 
     Only baffle  707  exhibits a closed conical baffle surface, as compared to the tips of the upper baffles which are open at the top to enable the gas to flow through in the direction of the hopper and the overlying baffle. 
     The conical opening of the delivery chute  706  or parts of the delivery chute  706  can be height-adjusted to the baffle  707  (or the baffle also) in order to regulate the influx of beans as required. 
     Highly efficient aspiration of the bean goods and efficient separation of the hulls is achieved by this cascading impacting arrangement. At least two, three or more baffles can be provided in exemplary embodiments. 
     It will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted. The scope of the invention is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein.