Water supply channel for evenly wetting a hybrid dry cooler

Abstract

A hybrid cooler with selectively applied water to one or more heat exchangers has one or more water feed channels above each heat exchanger to which water is to be applied constructed to provide a smooth film of water by a feed channel overflow edge and with means for suppression of waves, if any, in the channel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view through a water supply channel with the water re-feeding in a baffle, the water through put opening and the curved overflow edge and the guide plate leading to the heat exchanger;

FIG. 2. shows a three-dimensional view of a water supply channel, with the water re-feeding in a baffle, the water through put opening and the curved overflow edge and the guide plate leading to the heat exchanger;

FIGS. 2 a and 2b are cross section views taken along break lines A-A and B-B, respectively in FIG. 2;

FIG. 3 is a partial section view of the channel corner showing an overflow late guide; and

FIG. 4 is a cross section view of the plate guide per se.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In accordance with FIG. 1 a state of the art hybrid heat exchanger 1 has several pipes 2, which run parallel to each other and which are located a distance apart from each other. The pipes 2 lie horizontal, which in FIG. 1 means vertical to the plane of the drawing. A stream of liquid is circulated through the pipes 2, whose temperature must lie above that of the ambient temperature.

On the pipes sit fins 3 along the length of the pipe which are located to increase the size of the airside heat exchange. Here it is above a compact heat exchanger whose fins 3 are drawn from several pipes 2. It could also be used where individual ribs are assigned to the individual pipes.

Above the upper face 5 of the fins 3, is located the water supply channel 6 of the wetting water 7, which is produced in large quantities, which can evaporate in the air current 4. The excess wetting water 7 is collected in a collection basin, which is not shown here, and is recycled by a pump to the supply channel 6.

By way of a pipe 8, which is open at the bottom, the wetting water 7 is fed into the inside of the channel into the baffle, where it is braked by the walls themselves and by the counter pressure of the supply channel 6 in all expansion directions. As a result of the slightly increased pressure within the baffle 9, in comparison to the supply channel, the water flows through the openings 10 in the baffle, which lie on the floor of the supply channel and which lie approx in the middle of the baffle.

As a result of the low flow speed, from the baffle through put 10, the surface 11 of the wetting water 7 in the supply channel 6 remains fully undisturbed. With re-feeding of the wetting water 7 the water level 11 rises to the height of the overflow edge 12 of the shaped guide plate 13, which is in the direction of flow. The curved guide plate 13 lies on the channel side just beneath the water level 11. The immersion depth X in the channel 6 is several millimeters, which causes the water level 11 to be calmed. As a result of the depth of the shaping of the longitudinal slots, the surface tension of the water is so strongly disturbed that it spreads, as an even film, over the guide plate 13 to the heat exchanger 1.

The guide plate 13 can be fitted both vertically and also slightly inclined. For fixing the guide plate double adhesive tapes 14 are employed and individual rivets 15 or other methods of binding, which create a watertight connection.

To prevent a disruption of the water film at the overflow 16 on the heat exchanger 1, the water supply channel 6 can be adjusted in height, which is indicated by a double arrow 17. This water supply channel 6 can also be adjusted in the horizontal direction, which is indicated by a double arrow 18.

FIGS. 1, 2 and 2b show a water supply channel 6 with built-in baffle 9, the through flow openings 10, the through flow openings 10 and the curved guide plate 13 at the overflow edge 12. The flow openings 10 are preferably in mid-length of the pipe , not at the ends . Securing rivets 15 are distanced from the overflow edge 12 so that on this no material dripping is caused. The guide plate has a near end 13a and a lower end 13b which is below the height of the calmed water surface.

The quantity of additional water and the length of the supply channel 3 determine the length of the baffle 9, which is approximately 10-90% of the channel length 6. The through flow openings 10 are dimensioned so that the returning wetting water is about equal to that which is fed over the guide plate 13 to the heat exchanger 1. The guide plate 13 is arranged over the whole channel length and extends from the overflow edge 12 to near the heat exchanger 1.

FIG. 4 shows that the guide plate is smooth on one side (inside contact side) and roughened on the other side. Such roughening may be done by blasting with sand or glass or ceramic shot or by grooving tools or by corrugation and in all such methods are designed so that the when the plate is assembled as shown in FIG. 3 the roughening or grooving or corrugation provides vertical (more or less) vertical paths to guide the overflow water downwards as a smooth film

It will now be apparent to those skilled in the art that other embodiments, improvements, details, and uses can be made consistent with the letter and spirit of the foregoing disclosure and within the scope of this patent, which is limited only by the following claims, construed in accordance with the patent law, including the doctrine of equivalents.

Claims

1. Water supply channel for evenly wetting a hybrid dry cooler, particularly for large refrigeration systems for heat transfer between a liquid and a gas with partial latent heat emission, and comprising means for re-feeding water for the wetting of a heat exchanger, the improvement wherein the apparatus is constructed so that the re-feed water flows from an open pipe in the baffle which is fed by the retaining and separating device of a water supply channel, where it flows through one or more openings of a baffle or fracture of the channel by means of static pressure and then as a calmed water surface flows over an overflow edge of the channel to the heat exchanger.

2. Water supply channel according to claim 1, wherein the wetting water is fed vertically from above the channel wall and through the baffle or from below through the channel floor.

3. Water supply channel according to claim 1, wherein flow through the openings and over the baffle of the retaining and separating device is such that only so much water flows as well prevent the creation of waves or partial raising of the water level in the supply channel.

4. Water supply channel according to claim 1, wherein the slits on the guide plate lie in the direction of flow of the wetting water or at an angle to it.

5. Water supply channel according to claim 1, as applied to a dry cooler with a timed heat exchanger, wherein the guide plate ends directly at the fins or a distance from the fins.

6. Water supply channel according to claim 1, wherein the water supply channel is open at the top for unhindered cleaning or is closed at the top to stop the build up of dirt.

7. Water supply channel according to claim 1, wherein the overflow curved guide plate is roughened using sand or glass streams.

8. Water supply channel according to claim 1, wherein the overflow side of the channel comprises a slotted or roughened metal sheet, with a lower end which extends beneath the calmed water surface.

9. Water supply channel according to claim 1, wherein the supply channel (6) is adjustable in height and horizontally.

10. Water supply channel according to claim 1, wherein the heat exchanger is of a fin-tube type fitted with fins for several pipes or the heat exchanger consists of several individual finned tubes.