Heat exchanger using corrugated sheets

Abstract

In an MVR evaporator, a heat exchanger core comprises several condensing units. Each unit comprises front and back corrugated sheets, arranged trough-to-trough. The units are arranged side-by-side, in peak-to-trough configuration, creating sinuous passageways between the units. Steam is fed into the units through port-pipes, and the units are physically supported via the port-pipes from steam manifolds.

1 . Heat exchanger apparatus, wherein:
 the apparatus includes several heat transfer units, and in respect of each unit:
 the unit includes front and back corrugated sheets, which are fastened together in a trough-to-trough configuration; 
 the unit includes sheet-spacers, and the sheet-spacers hold adjacent corrugation troughs of the front and back corrugated sheets in a spaced-apart relationship, a distance D 1  apart; 
 the unit includes peripheral seals, which straddle sealingly between the spaced-apart sheets, 
 thereby creating a sealed and enclosed interior space between the sheets and between the seals; 
 the unit includes inlet and outlet ports, through which fluid can be introduced into, and discharged from, the interior space; 
   the several heat-transfer units are arranged side by side, and form a core of the heat exchanger apparatus;   the apparatus includes a support, in which the several units of the core are mounted, and the support is structured to so mount adjacent heat-transfer units, in the core, that:
 the front sheet F-U 1  of one of the heat transfer units U 1  faces the back sheet B-U 2  of the next adjacent unit U 2 ; 
 the said front and back sheets F-U 1  and B-U 2  face each other in a peak-to-trough configuration; 
 the support includes unit-spacers, and the unit-spacers hold the units U 1  and U 2  in spaced-apart relationship, a distance D 2  apart; 
 the distance D 2  between the sheets F-U 1  and B-U 2  is large enough to create and define a passageway between those sheets, which is large enough to enable fluid to pass between those sheets; 
 the distance D 2  is small enough that fluid, in passing through the passageway between the units U 1  and U 2 , and in encountering the peaks and troughs of the sheets F-U 1  and B-U 2 , is forced by such encounters to undergo respective substantial changes of direction; 
 whereby the passageway created between adjacent heat-transfer units can be characterized as sinuous. 
   
   
   
       2 . As in  claim 1 , wherein the arrangement of the apparatus is such that fluid passing through the sinuous passageway encounters at least three peaks each of the corrugated sheets F-U 1  and B-U 2 , being at least six peaks in aggregate. 
   
   
       3 . As in  claim 1 , wherein:
 in respect of a path-line that traces the shortest path that fluid can take in passing through the passageway;   the path-line passes from a peak P 1 -F-U 1  of the sheet F-U 1  to a peak P 1 -B-U 2  of the sheet B-U 2 , and then to a peak P 2 -F-U 1  of the sheet F-U 1 , and then to a peak P 2 -B-U 2  of the sheet B-U 2 , and so on;   the portion of the path-line joining peak P 1 -F-U 1  to peak P 1 -B-U 2  lies at an angle A to the portion of the path-line joining peak P 1 -B-U 2  to peak P 2 -F-U 1 ;   the angle A is no more than about 150 degrees.   
   
   
       4 . As in  claim 1 , wherein:
 the corrugations of sheet F-U 1  are of the same pitch and the same peak-to-trough height, being PTH centimetres, as the corrugations of sheet B-U 2 ;   the distance D 2  between the sheets F-U 1  and B-U 2  is smaller than the height PTH, whereby the peaks of sheet F-U 1  overlap the peaks of the sheet B-U 2 ;   and preferably D 2  is about one-half of PTH.   
   
   
       5 . As in  claim 1 , wherein the sheet-spacers that hold the sheets the distance D 1  apart in the unit include spacer-strips of thickness D 1 , fasteners go through them, at the troughs, clamp sheets onto spacer-strips. 
   
   
       6 . As in  claim 1 , wherein:
 the peripheral seals include left and right masses of filler-sealant; and   each mass straddles between the front and back sheets.   
   
   
       8 . As in  claim 1 , wherein the inlet and outlet ports of the unit comprise respective inlet and outlet port-pipes. 
   
   
       9 . As in  claim 8 , wherein the port-pipes are embedded in the filler-sealant. 
   
   
       10 . As in  claim 1 , wherein:
 the apparatus includes an inlet manifold;   the inlet manifold is formed with pipe-holes, the walls of which are suitably sized to receive the port-pipes of the several units;   the walls of the pipe-holes in the inlet manifold are so positioned relatively that, when the port-pipes of the several heat transfer units are received therein, the walls of the pipe-holes constrain the port-pipes of one unit against movement towards and away from the other units;   whereby the walls of the pipe-holes of the inlet manifold serve as the said unit-spacers.   
   
   
       11 . As in  claim 10 , wherein the walls of the pipe-holes in the inlet-manifold are so positioned relatively as to support the several units, the port-pipes of which are received therein, in the said peak-to-trough configuration. 
   
   
       12 . As in  claim 1 , wherein:
 the HE apparatus is a component of an evaporator;   in the evaporator, incoming water containing a dissolved contaminant at a dilute contamination is evaporated, whereby, in the outgoing final water, the contaminant is more concentrated;   the arrangement of the evaporator is such that, in use, steam entering the inlet ports of the units is condensed upon passing through the units, and water passing through the passageways is evaporated.   
   
   
       12 . As in  claim 1 , wherein:
 the evaporator is an MVR evaporator;   the evaporator includes a chamber, in respect of which:
 the contaminated water is circulated through the sinuous passageways; 
 steam is drawn, and compressed, and then fed into the inlet ports of the heat transfer units.