Process for fast and homogeneously heating a liquid product and apparatus for such process

An apparatus, comprising at least two vertically mounted, longitudinal, heating chambers that are arranged in series in a vertical arrangement, each chamber having a lower end and an upper end and an inlet for liquid at one end and an outlet for liquid at the other end,

• wherein each heating chamber defines a longitudinal flow path for liquid between its inlet and its outlet and the arrangement of the at least two heating chambers in series defines a vertical liquid flow path through the at least two heating chambers,
• wherein each heating chamber is provided with a first electrode at its lower end and a second electrode at its upper end and the first and second electrode of each chamber are separated by an electrical insulator, and the second electrode of a preceding chamber is the first electrode of the next chamber in series and together form a connecting electrode,
• wherein the electrodes are arranged such that liquid flowing through the vertical liquid flow path through the at least two heating chambers during normal operation of the apparatus, is in contact with the first and with the second electrode of each heating chamber,
• wherein the first electrode of the lowest heating chamber of the vertical arrangement and the second electrode of the upper heating chamber of the vertical arrangement are electrically grounded,
• wherein each connecting electrode is electrically connected to a direct current (DC) power source to apply an electrical charge to each connecting electrode,
• wherein the connection to the DC power source is in such configuration that the polarity of the electrical charge of each connecting electrode can be continuously reversed at a frequency of at least 500 Hz and the electrical charge of adjacent connecting electrodes is opposite.