GB2164869A

GB2164869A - Liquid distributor plate

Info

Publication number: GB2164869A
Application number: GB08521895A
Authority: GB
Inventors: Philipp Messerschmidt; Claus Elle; Harald Muller; Gerd Fiebich; Michael Muller; Mathias Dorr
Original assignee: LEIPZIG CHEMIEANLAGEN
Current assignee: LEIPZIG CHEMIEANLAGEN
Priority date: 1984-09-03
Filing date: 1985-09-03
Publication date: 1986-04-03
Also published as: GB8521895D0; IT8567748A0; HU193130B; DE3530672A1; DD248419A1; HUT40259A; FR2569830A1; ATA254785A; IT1183937B

Abstract

A liquid distributor plate for the uniform distribution of liquids upon the outer surfaces of vertically arranged tubes is used in apparatuses for heat and substance exchange. The liquid distributor plate consists of an thin deformable plate 3 (eg. of metal foil or plastics) and a support plate 8. The thin plate comprises openings for the tubes 5 and liquid passage openings in uniform distribution around these. The liquid passage openings are formed as conical, radially outwardly narrowing slots. They are situated in the funnel-type deformations 10 which form around each tube when the liquid distributor plate is fitted with tubes. <IMAGE>

Description

SPECIFICATION Liquid distributor plate The invention relates to a liquid distributor plate for the uniform distribution of liquids upon the outer surfaces of vertically arranged tubes, especially upon tubes in heat-exchange and substance-exchange apparatuses, such for example as evaporators, coolers, adsorbers and expellers.

The optimum distribution of liquids upon the external surfaces of vertically arranged tubes has caused great problems in practice hitherto.

The efficiency of the heat and substance exchange is dependent upon an optimally sprinkled surface. Apart from the selection of a suitable solution, its good realisability and durability are needed in order to achieve high efficiency.

Many proposed solutions have become known internationally. Development continues despite the multiplicity of solution variants.

More especially it is to be ascertained that the more recent solutions vary the distribution by an annular gap arranged around the tube.

Thus there are many solutions which propose the insertion of a component of special configuration into the gap, in order to centre the tubes.

Such a solution is also proposed in Fed.

German Pub. Sp. No. 1,551,406. Disadvantages of these solutions are the expense in assembly in the fitting-on of centring sleeves and the incomplete achievement of centring, because sufficient play must be present due to the tube tolerances. However even minor deviations from concentricity lead to defective distribution of the liquid.

From Fed. German Publ. Sp. No. 3.317,951 a liquid distributor plate for external sprinkling is also known which uses the annular gap for sprinkling. Since the centring of the tubes is not described, the known disadvantages of these annular gap solutions are to be expected here.

The solution as set forth in GDR P.S. No.

46,672 represents a liquid distributor plate in which half-round openings permitting passage of liquid from the plate to the tube are arranged in distribution around the tubes. In the case of this solution the diameters of the openings for the tubes are equal to the external diameter of these tubes.

This solution has the disadvantage that only calibrated tubes can be used, because otherwise assembly would not be possible by reason of the positive tolerances of the tube external diameters. Since the heat transmitter units consist of many tubes arranged side by side, the use of calibrated tubes becomes economically expensive and will thus be reserved only for special cases.

Although with this kind of solution a good distribution of the liquid over the external surfaces of the tubes is achieved and the problem of centring does not exist at all (because of positive centring), the solution cannot be widely accepted for economic reasons.

The aim of the invention is the provision of a liquid distributor plate which is of simple and operationally reliable assembly and causes no centring problems or fitting problems in the case of the use of tubes having different external diameters (in the tolerance range).

The invention is based upon the problem of developing a liquid distributor plate for the distribution of liquids upon the external surfaces of a large number of vertically arranged tubes which guarantees complete wetting of the tube external surfaces.

In accordance with the invention this problem is solved in that the liquid distributor plate consists of two plates arranged one above the other, an unstable function plate and a selfcarrying support plate. The self-carrying support plate comprises, adequately for the openings in the function plate, likewise openings, which however are larger in diameter. The function plate of the liquid distributor plate is deformed around each tube in funnel form towards the support plate. In this funnel-type deformation there are arranged conical, radially outwardly narrowing slots. These slots form the liquid passage openings which are distributed uniformly around each tube. The diameter of the openings for the tubes in the function plate is equal at the exit to the external diameter of the tubes.Specific demands are made of the material for the function plate, as regards the resilience behaviour.

Thus the unstable function plate can be a metal foil the funnel-type deformations of which rest resiliently on the tube outer wall.

The same result can be achieved also with a hard plastics foil or even with soft plastic elastomers. These resilient properties of the function plate are also necessary for the fitting of this liquid distributor plate. For the first time it becomes possible to produce a liquid distributor plate of this type (external diameter of the tubes and diameter of the openings in the liquid distributor plate of equal size) economically, because the described functional condition, where the liquid distributor plate rests closely on the external walls of the tubes, is established only after assembly. Before the fitting of the tubes the diameters of the openings in the unstable function plate are smaller than the external diameters of the tubes. As yet the function plate has no funneltype deformations and the liquid passage openings are merely indicated in the form of radial incisions.Only with the fitting of the tubes, which are conducted from above through the unstable function plate, do the funnel-type deformations of the function plate take place, until the diameter of the openings has widened to the external diameter of the tubes.

The production of the conical, radially outwardly narrowing liquid passage openings from the original incisions takes place in synchronism with this widening action. The tubes are pushed through completely and fixed in the base plate.

In the case of this liquid distributor plate, consisting in accordance with the invention of function plate and support plate, deviations of the external diameters have no negative effects of any kind upon the assembling and the operation. The configuration of the liquid passage openings as conical, radially outwardly narrowing gaps guarantees in the case of different external diameters of the individual tubes a different gap width for each and thus an adquate passage of liquid in each case.

The open area of the liquid passage openings results necessarily in dependence upon the external diameter of the individual tubes. The function plate lies tightly against each tube outer wall in individual arcs which are interrupted each only by the liquid passage openings. The support plate has only the task of stabilising the function plate. Therefore it can consist of punched flat material or of a lattice construction. The openings in the function plate can be round or square.

The advantages of the liquid distributor plate in accordance with the invention consists in the guarantee of a uniform distribution of the liquid, even a small quantity of liquid, on the entire tube circumference in a relatively slight film layer, whereby good substance and heat exchange is ensured.

Further advantages are the simple, economical production of the liquid distributor plate and the use of tubes with manufacturing tolerances in the external diameter.

The liquid quantity required for the sprinkling film formation can be predetermined by the fixing of the number and length of the incisions for the liquid entry openings.

The invention will be represented in greater detail below. In the drawing: Figure 1 shows a vertical section through a bundled-tube heat exchanger in the region of the liquid distributor plate, Figure 2 shows a plan view of the liquid distributor plate in the bundle-tube heat exchanger, Figure 3 shows a detail of the plan view of the liquid distributor plate without tubes.

In a vertically placed bundled-tube heat exchanger according to Fig. 1, a liquid distributor plate 1 is arranged in the upper region and is gas-permeably connected with the wall 2 of the bundled-tube heat exchanger.

The liquid distributor plate 1 consists of the function plate 3 with the openings 4 for the tubes 5 and the liquid passage openings 6.

The function plate 3 consists of a metal foil.

It is smaller in diameter than the bundled-tube heat exchanger and is surrounded by a vertically arranged limitation 7. This function plate 3 has properties of resilience and is unstable.

Therefore it is arranged on a support plate 8.

The support plate 8 is a self-carrying punched perforated plate of metal. The openings 9 in the support plate 8 are larger in diameter than the openings 4 in the function plate 3, but arranged adequately for these. The diameter of the openings 9 in the support plate 8 is also larger than the external diameter of the tubes 5.

As a result of the fitting of the liquid distributor plate 1 with tubes, the function plate 3 has funnei-type deformations 10 towards the support plate 8, around each tube 5, and the liquid passage openings 6 in the funnel-type deformations 10 are formed as conical, radially outwardly narrowing slots.

A cooling liquid which is to be distributed uniformly over the external surfaces of all tubes 5 is fed by way of the liquid distributor plate 1 to the bundled-tube heat exchanger.

For this purpose the cooling liquid is fed by way of at least one conduit on to the function plate 3. The cooling liquid flows by way of the funnel-type deformations 10 and the liquid passage openings 6 directly on to the external surfaces of the tubes 5 and is immediately uniformly distributed over the entire circumference, so that an uninterrupted trickling film flows permanently over the other surfaces of all tubes 5 and guarantees the desired heat transmission.

To guarantee the exact abutment of the function plate 3 of the liquid distributor plate 1 on the outer wall of the tube 5 (external diameter of tube 5 is equal to the diameter of the openings 4 in the function plate 3) and to avoid problems which have their cause in the plus tolerances of the tube external diameters, the openings 4 of the function plate 3 are produced with a diameter which is about 25% smaller than the external diameter of the tube 5. In uniform distribution around these openings 4 there are arranged several radial incisions. In the fitting of this function plate 3 with tubes, funnel-type deformations 10 occur around the tubes 5, by reason of the abovementioned differences of diameter, and at the same time the incisions open into conical, radially outwardly narrowing slots, the liquid passage openings 6.

The liquid distributor plate in accordance with the invention secures the good distribution of a small quantity of liquid on the tube circumference in a relatively small coating of film. Thus an intensive substance and heat exchange is guaranteed. The construction of the liquid distributor plate 1 renders economical production possible. The sprinkling quantity can be determined by the fixing of the number and length of the incisions for the liquid passage openings.

Claims

1. Liquid distributor plate for the uniform distribution of liquids upon the external surfaces of vertically arranged tubes, of which plate the openings for the tubes have a diameter which is equal to the external diameter of the tubes, and liquid passage openings are arranged in uniform distribution around the tubes and in operative connection with them, characterised in that the liquid distributor plate (1) consists of an unstable function plate (3) with liquid passage openings (6) which rests on a self-carrying support plate (8) perforated adequately for the openings (4) for the tubes (5) in the function plate (3), the openings (9) in the support plate (8) have a larger free cross-section than the openings (4) in the function plate (3), the function plate (3) consists of a material with resilience properties and comprises around each tube, as a result of the fitting of the tubes, a funnel-type deformation (10) towards the support plate (8), and the liquid passage openings (6) in the funneltype deformations (10) are formed as conical, radially outwardly narrowing slots.

2. Liquid distributor plate according to Claim 1, charaacterised in that the unstable function plate (3) is a metal foil.

3. Liquid distributor plate according to Claim 1, characterised in that the unstable function plate (3) consists of plastics material.

4. Liquid distributor plate according to Claims 1 to 3, characterised in that the selfcarrying support plate (8) is a lattice construction and the adquately arranged openings (9) in the support plate (8) are square.

5. Liquid distributor plate for the uniform distribution of liquids upon the external surfaces of vertically arranged tubes as claimed in Claim 1, substantially as herein described with reference to and as illustrated by any one of the examples shown in the accompanying drawings.