Apparatus for heating flowing material containing solids

#The present invention relates to a device for heating flowing material containing finely divided solids, such as concentrate slurry containing precious metals and/or precious minerals, up to a desired temperature range, for instance to a temperature range used in the treatment process of said material.

#The heating of a concentrate slurry containing finely divided solids, such as precious metals and/or precious minerals, up to the temperature range used in the treatment process is usually carried out in a heat exchanger with a hot, liquid medium, such as water or vapor. However, the concentrate slurry is an extremely abrasive and easily settling material which is difficult to treat in heat exchangers. The reason for said difficulty is that the ducts provided in heat exchangers for the flowing of the heated material often are essentially very narrow, and the duct walls are thin. Consequently, in the treatment of concentrate slurries, the heat exchanger ducts wear rapidly off or are blocked, if the flow is too weak in order to carry the solids along with the liquid phase present in the slurry.

#The object of the present invention is to eliminate some of the drawbacks of the prior art and to achieve and improved apparatus that is more secure in operation for heating flowing material containing finely divided solids, such as concentrate slurry containing precious metals and/or precious minerals, up to the temperature range applied in the treatment process of said material, when a heat exchanger is employed for heating. The essential novel features of the invention are apparent from the appended claims.

#The invention is explained in more detail with reference to the appended drawing, which illustrates a preferred embodiment of the invention, seen from the side in a partial cross-section.

#According to the drawing, the heating of a flowing concentrate slurry containing finely divided solids, such as precious metals and/or precious minerals, up to a desired temperature range applied in the treatment process of said material, is carried out in an essentially vertically installed heat exchanger 1. The water or vapor needed in the heating is fed to the top part of the heat exchanger 1, via a feed duct 2, to essentially vertically installed flow channels 3, where the flowing direction of the heating medium proceeds from top to bottom. As for the concentrate slurry to be heated, it is fed via its inlet conduit 4 to a feed chamber 5 provided in the bottom part of the heat exchanger 1. From the feed chamber 5, the concentrate slurry to be heated is further conducted from the bottom upwards in between the flow channels 3. When flowing between the flow channels 3, the concentrate slurry to be heated is maintained in suspension in order to prevent classification. The heated concentrate slurry is further removed from the top part of the heat exchanger 1 via an outlet conduit 6. The water or vapor used for heating is discharged via an outlet conduit 7 provided in the bottom part of the heat exchanger 1.

#Moreover, underneath the concentrate slurry feed chamber 5, there is formed a chamber 8 whereto there is fed, via a feed conduit 10, air and/or water used in the cleaning of the feed chamber 5. In order to conduct the air and/or water that was fed into the chamber 8 further to the concentrate slurry feed chamber 5, on the bottom of the concentrate slurry feed chamber 5 there is installed a mushroom valve 9 that is operated by the pressure defined by the air and/or water fed in the chamber 8. By means of the air and/or water fed in said chamber 8, the bottom of the concentrate slurry feed chamber 5 is cleaned of possible concentrate particles that came along with the concentrate slurry and were left on the bottom, which particles are not—owing to their coarseness, for example—carried along with the upwardly, from bottom to top, flowing vertical concentrate slurry flow. The material that should be removed from the chamber 8 by cleaning, as well as the medium used in the cleaning process, are discharged from the heat exchanger 1 via a discharge conduit 11 provided on the bottom of the heat exchanger 1.

#Further, in order to provide for the maintenance of the apparatus 1 according to the invention, in the top part of the apparatus, there is installed a door 12. Moreover, in the drawing there is shown, marked with number 13, an overflow conduit wherethrough the heated concentrate slurry can be discharged in possible malfunction situations.