Shell-and-Tube Heat Exchanger

Abstract

A shell-and-tube heat exchanger for the treatment of juices and juice-type foodstuff products with medium to high viscosity, with at least one jacket tube containing at least one inner tube, whereby the inner tube and/or the jacket tube is or are formed as a swirl tube with multi-start spirals running like a thread at an angle to the tube axis, a crossed and twisted tube with crossing spirals at least essentially symmetrical to the tube axis, each with an angle of incidence between 67° and 72° to the tube axis, i.e. with an angle of twist of 23° to 18° to the tube axis, is used as an inner and/or outer tube. The spiral depth is about 0.8 mm to 1.2 mm.

1 . Shell-and-tube heat exchanger for the treatment of juices and juice-type foodstuff products with medium to high viscosity, comprising at least one jacket tube containing at least one inner tube, the inner tube and/or the jacket tube is or are formed as a swirl tube with multi-start spirals running like a thread at an angle of twist to the tube axis, and, as an inner and/or outer tube a crossed and twisted tube is provided with mutually crossing spirals at least essentially symmetrical to the tube axis, each with an angle of incidence between 67° and 72° to the tube axis and the angle of twist resulting from it of 18° to 23° perpendicular to the tube axis. 
     
     
         2 . Shell-and-tube heat exchanger according to  claim 1 , wherein each spiral has in cross-section a cavity-type indentation with ribs on both sides and approximately wedge-shaped in cross-section, between which, in the indentation, a spiral depth between about 0.8 mm to 1.2 mm is present. 
     
     
         3 . Shell-and-tube heat exchanger according to  claim 2 , wherein the width of the indentation viewed in the direction of the tube axis is a multiple of the spiral depth. 
     
     
         4 . Shell-and-tube heat exchanger according to  claim 1 , wherein both multi-start spirals fully cover the tube surface. 
     
     
         5 . Shell-and-tube heat exchanger according to  claim 1 , wherein the jacket tube contains a plurality of crossed and twisted inner tubes as the crossed and twisted tube and forms a module of the shell-and-tube heat exchanger. 
     
     
         6 . Shell-and-tube heat exchanger according to  claim 2 , wherein the jacket tube has the indentations of the spirals on the inner side of the tube and that the respective crossed and twisted inner tube has the indentations of the spirals on the outer side or the inner side. 
     
     
         7 . Shell-and-tube heat exchanger according to  claim 1 , wherein juices and juice-type products with viscosities>about 5 mPas can be processed in the shell-and-tube heat exchanger. 
     
     
         8 . Shell-and-tube heat exchanger according to  claim 7 , wherein the juice or juice-type product is processed according to a recuperative method with product separated against product by the respective crossed and twisted tube. 
     
     
         9 . Shell-and-tube heat exchanger according to  claim 7 , wherein the juice or juice-type product is processed according to a method with a heat transfer medium separated against the product by the respective crossed and twisted tube. 
     
     
         10 . Inner and/or jacket tube of a shell-and-tube heat exchanger for the treatment of juices or juice-type foodstuff products with a viscosity>about 5 mPas, comprising a crossed and twisted tube with mutually crossing multi-start spirals at least essentially symmetrical to the tube axis is used as an inner or jacket tube, and that the angle of incidence (α, α 1 ) to the tube axis is between 67° and 72° and the spiral depth in the indentations formed by the spirals is between about 0.8 mm to 1.2 mm. 
     
     
         11 . Shell-and-tube heat exchanger according to  claim 2 , wherein the indentations and the ribs are arranged on the surface of the jacket and/or inner tube in contact with the product. 
     
     
         12 . Shell-and-tube heat exchanger according to  claim 3 , wherein the width of the indentation is between about 5.0 and 20.0 mm. 
     
     
         13 . Shell-and-tube heat exchanger according to  claim 9 , wherein each spiral has in cross-section a cavity-type indentation, and the indentations face the product.