FR2479437A1 - Vapour condenser partic. for solar powered desalination evaporator - has very thin plates alternating with horizontal and vertical corrugations - Google Patents

Abstract

The heat exchanger comprises a pair of corrugated plates, each with a thickness of only a few tenth of a mm. The corrugations of both plates are vertical sandwiched between the two vertical corrugation (VC) plates is a third, identical plate with its corrugations disposed horizontally. The plates are connected for vapour to flow between the two VC plates while a cooling liq. is trickled down the outer surfaces of these VC plates. Sandwich type heat exchanger modules as described above can be combined in a multi-module heat exchanger. Each pair of adjacent modules has an intermediate separator plate identical to the middle plate of each module. The plates can be made of plastics or metal. Highly efficient heat transfer is achieved which is vital when the temp. difference between vapour and cooling liq. is quite small. The corrugations stiffen the very thin plates.

Description

Heat exchange structure for plate condenser and plate condenser
The invention relates to a heat exchange structure for a plate condenser and a plate condenser comprising such a structure.

 More particularly, the invention applies to a condenser where the fluid to be condensed and the coolant have a small temperature difference and where the temperature of the vapor to be condensed is relatively low. A good example of application is given by a steam condenser of a solar-powered sea water distillation plant, in which the steam coolant consists of sea water trickling on the plates. of the condenser.

 The invention thus relates to a high performance condenser.

 The invention therefore relates to a heat exchange structure for plate condenser characterized in that it comprises two thin plates of the order of a few tenths of a millimeter, wavy, the generators of the corrugations being vertical and in that 'Between these two plates is disposed a third identical plate but whose generators of the corrugations are placed horizontally, the vapor passing between the first two plates and the coolant trickling from top to bottom against the external surfaces of the first two plates.

 The invention also relates to a plate condenser comprising a plurality of structures as defined above, characterized in that said structures are separated from each other by a thin plate identical to the other plates and arranged in the same way as said third plate.

 The invention will be better understood thanks to the description of an embodiment of the invention made below with reference to the appended drawing comprising a single figure and showing in partial perspective a condenser according to the invention.

 The set includes thin corrugated plates 1, 1 ', 2, 2'.

These plates are as thin as possible, of the order of a few tenths of a millimeter thick, are made of metal or else of plastic, so that this is compatible with the fluids and the temperatures present.

 The generators of the corrugations are vertical. These undulations make it possible to ensure a certain rigidity in these thin plates and also make it possible to increase the exchange surface available in a given volume of exchanger.

 To prevent the corrugated walls from touching under the effect of an overpressure of a fluid with respect to the other, there are identical plates 3, 4, 5 between the preceding plates, but whose generatrices are placed horizontally . Oji can also place a 6 plate in the same way at the end of the package.

 The steam is then sent, for example horizontally according to the arrows F between the plates 1 and 1 'and between the plates 2 and 2' while cooling water is poured in a runoff according to the arrows F1 against the external walls (relative steam path) of plates 1, 1 ', 2 and 2'.

 These plates 3, 4, 5 and 6 complete the rigidity of the assembly and do not modify the steam passage section.

 As an example of a particularly interesting application, we can cite the case of a condenser in a seawater desalination system where the vapor comes from an evaporator by solar energy.

The steam condenses on the plates and fresh water is collected.

The external walls of the plates 1, 1 ', 2 and 2' are sprinkled with water by salt water from a previous stage.

The plates are made of non-corrodible material, for example stainless steel or brass.

Claims (1)

 . ' heat exchange structure for plate condenser, characterized in that it comprises two thin plates of the order of a few tenths of a millimeter, corrugated, the generators of the corrugations being vertical and in that between these two plates is arranged a third identical plate but whose generatrices of the corrugations are placed horizontally, the vapor passing between the first two plates and the coolant flowing from top to bottom between the external surfaces of the first two plates.  2 / plate condenser comprising a plurality of heat exchange structure according to claim 1. characterized in that said structures are separated from each other by a thin plate identical to the other plates.s and arranged in the same way as said third plate.