JP2001221533A - Down-flow liquid film type heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a down-flow liquid film type heat exchanger having relatively long heat transfer tubes which can be installed easily. SOLUTION: Heat transfer tubes for transferring heat by flowing liquid down on the outer circumferential surface are wound in pancake-shape and disposed in layer at an interval in the vertical direction. Headers for branching fluid being fed through the heat transfer tubes are provided at the end parts of the inner and outer layers of the heat transfer tubes wound in pancake-shape. The heat transfer tubes wound in pancake-shape and adjacent in the direction of inner/outer layer and vertical layer are preferably partitioned by means of a rod or a wire.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a falling liquid film heat exchanger in which a liquid flows down an outer peripheral surface of a heat transfer tube to perform heat transfer. This type of heat exchanger is used in seawater desalination equipment, absorption refrigerators, chemical processing equipment, and the like.

[0002]

2. Description of the Related Art A falling liquid film type heat exchanger is constituted by arranging a large number of heat transfer tubes horizontally in a sealed container. A fluid flows inside the heat transfer tubes, while a liquid flows from above the heat transfer tubes. Is supplied, the liquid flows down in a film form along the outer peripheral surface of the heat transfer tube, and the fluid inside and outside the heat transfer tube exchanges heat.

For example, in an absorption refrigerator, an absorber, an evaporator,
The condenser constitutes a falling film type heat exchanger, most of which is a shell and tube type. The shell-and-tube heat exchanger is manufactured by attaching a heat transfer tube to a body having a large number of holes on the side surface for passing the heat transfer tube. The number of heat transfer tubes attached to each heat exchanger is as high as several hundreds, and the length of the heat transfer tubes tends to be longer in larger refrigerators.

[0004]

As described above, the conventional falling film type heat exchanger has a shell-and-tube type in which a large number of holes are formed in a side surface of a body, and a heat transfer tube is attached through a hole. In addition, since the number of heat transfer tubes is as large as several hundreds, and the length of the heat transfer tubes in a large-sized refrigerator is long, enormous labor was required in manufacturing the heat exchanger.

An object of the present invention is to provide a heat exchanger of the falling liquid film type in which the length of a heat transfer tube is relatively long and which can be easily installed.

[0006]

In the falling liquid film heat exchanger provided by the present invention, a heat transfer tube for causing a liquid to flow down to the outer peripheral surface to perform heat transfer is wound into a pancake shape. The heat transfer tubes wound in a vertical direction are arranged in a layer at a certain interval in the vertical direction, so that the relatively long heat transfer tubes are compacted and the size of the heat exchanger is suppressed. Such a pancake-shaped heat transfer tube can be assembled on a separate line, and can be attached to the heat exchanger main body only with a branching header, so that much labor is not required.

[0007] At the ends of the inner and outer layers of the heat transfer tube wound in a pancake shape, it is preferable to provide a header for branching the fluid flowing inside the heat transfer tube.

[0008] By separating the adjacent tube portions in the inner and outer layer directions and the upper and lower layer directions of the heat transfer tube wound in a pancake shape with a rod or a wire, it is possible to prevent the upper coil from bending due to gravity.

[0009]

FIG. 1 shows an embodiment of a falling liquid film heat exchanger according to the present invention using a heat transfer tube and a branch header.

As shown in FIG. 1, the heat transfer tube 1 is wound in a pancake shape (spiral shape; spiral shape), and this pancake state is maintained by forming it into a pancake shape. is there. The heat transfer tubes 1 wound in a pancake shape are stacked so as to form layers in the vertical direction. Branching headers 2 and 2 are attached to the inner and outer layer ends of the heat transfer tube wound in a pancake shape, and any of the heat transfer tubes stacked up and down is connected to the branch header 2.
It is attached collectively to.

[Specific Example] Outer diameter 12.70 mm, inner diameter 11.
A 70mm, 5m long semi-rigid copper tube is formed into a spiral shape by a winder with a tension control mechanism, and stacked vertically in 5 stages. Both ends of each coil are brazed to the branch header. At once.

In order to prevent the upper coil from bending due to gravity, the inner and outer layers of the coil and the upper and lower layers are separated from each other by thin stainless steel rods. FIG. 2A shows an example in which the arrangement of the heat transfer tubes 3 is arranged in a grid pattern in up, down, left, and right directions, and a stainless steel bar 4 is provided between any of the upper, lower, left, and right tube portions.

FIG. 2B shows another example in which the arrangement of the heat transfer tubes 3 is arranged in a staggered arrangement of the upper, lower, left and right layers, and the adjacent tubes are separated by a stainless steel rod 4.

According to the pancake-shaped heat transfer tube constructed as described above, the heat transfer tube can be made more compact than the conventional shell-and-tube type, and the heat exchanger can be enlarged even when it is incorporated in the heat exchanger body. Can be prevented. In addition, such a pancake-shaped heat transfer tube can be assembled on a separate line from the heat exchanger body, and mounting on the heat exchanger body requires only a branch header, requiring much labor. And not.

[0015]

As described above, according to the present invention,
The intended problem of providing a heat exchanger of the falling liquid film type in which the length of the heat transfer tube is relatively long, which can easily perform construction; This greatly contributes to significant reductions and cost reduction of equipment.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention with a heat transfer tube and a header of a downflow type heat exchanger.

FIG. 2 shows an embodiment of the present invention by the structure of upper, lower, left and right layers of a heat transfer tube, wherein (a) is a cross-sectional explanatory view of an example in which the tubes are closely arranged in a grid pattern, and (b) is a staggered arrangement. Sectional explanatory drawing of the example.

[Explanation of symbols]

 1 Copper tube (heat transfer tube) 2 Header 3 Copper tube (heat transfer tube) 4 Stainless steel rod or wire

Claims (3)

[Claims] 1. A falling film heat exchanger in which a liquid flows down to an outer peripheral surface of a heat transfer tube to perform heat transfer, wherein the heat transfer tube is wound in a pancake shape, and the heat transfer tube wound in a pancake shape is provided. Are arranged in layers at a certain interval in the vertical direction. 2. A falling liquid film type heat exchange according to claim 1, wherein a header for branching a fluid flowing inside the heat transfer tube is provided at an end of the inner and outer layers of the heat transfer tube wound in a pancake shape. vessel. 3. The flowing liquid according to claim 1, wherein adjacent pipe portions in the inner and outer layer directions and the upper and lower layer directions of the heat transfer tube wound in a pancake shape are separated by a rod or a wire. Membrane heat exchanger.