JPS605321B2 - plate evaporator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a plate evaporator, and more particularly to a heat transfer plate of an impinging jet plate evaporator.

The applicant of this invention stated in ``Tokuiso Sho No. 52-5270,
An impinging jet plate heat exchanger has already been proposed.

Its configuration is as schematically shown in FIG.
Injection plates 1 and 2 with holes, and heat transfer plate 3
and 4, the first fluid is ejected from its joint space A through the small hole 5 of the ejection plate 1 or 2 to the ejection space B, and collides with the heat transfer surface of the adjacent and opposing propagation plate 4 or 3; Thus, heat is exchanged with the second fluid in the adjacent supply space C via the heat transfer plate 3 or 4. In the impinging jet type plate evaporator according to the present invention, the liquid to be evaporated is evaporated by heat exchange between the liquid to be evaporated, for example, the first fluid, and the heating medium, for example, the second fluid. By the way, in this type of plate-type evaporator, a jet of liquid to be evaporated ejected from a small hole in an injection plate collides with an opposing heat transfer surface, and the trailing stream of the jet forms an approximately circular shape centered on the jet collision point. It spreads to

In heat transfer by impinging jets, high heat transfer is achieved by reducing the thickness of the film on the heat transfer surface due to a sudden change in flow direction. The part of the heat transfer surface farthest from the jet impingement point has a lower jet flow velocity and is covered by the falling liquid from the upper part of the heat transfer surface.
This means that it is not very involved in heat transfer. In addition, if only the heat transfer coefficient is considered, it is preferable that the thickness of the heat transfer plate as a heat transfer element be as thin as possible because the thermal resistance will be small, but if strength is taken into account, there is a limit to reducing the plate thickness. be done.

In view of this, the heat transfer parts of the heat transfer plate, which are actively responsible for heat transfer, have been made thinner to reduce thermal resistance.
On the other hand, the gist of the present invention is to increase the thickness of the heat transfer plate portion, which is not significantly involved in heat transfer, so that the strength of the entire plate is reinforced at this portion. DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described in detail below based on embodiments shown in the accompanying drawings. In FIGS. 2 and 3, 6 is an injection plate having a large number of small holes 7 through which the liquid to be evaporated is ejected, and 8 is an injection plate on one side of which a jet of the liquid to be evaporated collides with a heat transfer surface and at the same time a heating medium is It is a heat transfer plate that flows or is sprayed along the heat transfer surface on the other side.

The heat transfer surface portion 9 of the heat transfer plate 8, which corresponds to the small hole 7 of the injection plate 6, has a thin section with a substantially circular area corresponding to the jet flow of the liquid to be evaporated. In other words, the ring heating surface portion 10 that is farthest from each jet impingement point, other than the above-mentioned substantially circular region corresponding to the jet castle of the liquid to be evaporated, is formed to have a relatively thick cross section. This thick heat transfer surface portion 10
supplements the strength of the thin heat transfer plate portion 9 as necessary, so that the strength of the entire heat transfer plate 8 is maintained. Thus, in the heat transfer plate of the impinging jet plate type evaporator, the heat transfer surface portion corresponding to the jet castle of the liquid to be evaporated is thinned, while the plate layer is thinned from the jet impingement point. Since the distant heat transfer surface portion, which is relatively unrelated to heat transfer, is formed to have a relatively thick plate thickness, the heat transfer performance can be improved without reducing the strength of the plate.

The present invention is particularly effective when a material with poor thermal conductivity, such as plastic, is used as the plate material.

However, in the case of plastic, it is easy to process or mold a plate having the above-mentioned shape.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the general structure of an impinging jet type plate heat exchanger, Fig. 2 is a front view of a plate showing an embodiment of the present invention, and Fig. 3 is a diagram taken along the mm line in Fig. 2. FIG. 6... injection plate, 7... injection hole,
8... Heat transfer plate, 9... Thin heat transfer surface portion, 10... Thick heat transfer surface portion. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1 It includes a heat transfer plate and an injection plate with a large number of small holes, and the liquid to be evaporated is ejected from its supply space through the small holes of the injection plate into the ejection space and onto the heat transfer surface of the adjacent and opposing heat transfer plate. In an impingement jet type plate type evaporator in which the heating medium is collided with the heating medium in the adjacent supply space through the heat transfer plate and evaporated, A plate type evaporator characterized in that a heat transfer surface portion corresponding to a liquid jet area is thin, while the remaining heat transfer surface portion farthest from each jet impingement point is relatively thick.