FR2758622A1 - LIQUID DISTRIBUTION NETWORK FOR ATMOSPHERIC REFRIGERANT - Google Patents

Abstract

This network comprises a set of tubes (1, 2, 3, 4, 5 () parallel to each other and substantially horizontal, connected at one of their ends by a collector or tank (6) for supplying liquid, and equipped liquid dispersers (7); a part (2, 4 () of the tubes is provided with means for putting these tubes practically out of the liquid circuit at the nominal liquid flow rate, and for using them as soon as an overflow occurs above the nominal flow rate; in the case of a network of the type with an open collector (6), the aforementioned means (8) can be bent ends forming spouts whose opening is located above the level of water corresponding to the nominal flow rate; in the case of a network with a collector, these means can be constituted by reversed brackets. In both cases, the nozzles and brackets are advantageously completed by constrictions or nozzles allowing a low flow rate of supply of the tubes corresponding to the nominal flow. The invention presents the ava ntage to allow the liquid flow to be increased up to approximately double its nominal value without risking damage to the network, and without requiring an additional auxiliary network.

Description

The present invention relates to a liquid distribution network in

  particular water, for industrial installation atmospheric refrigerant of the type comprising a set of tubes mutually parallel and substantially horizontal, connected at one of their ends by a collector or liquid supply tank, and equipped with dispersers liquid. It is known that in atmospheric refrigerants, hot water is distributed regularly, over the entire useful surface of the device, by a

  network of tubes connected to an indoor collector or an open pit.

  These tubes are fitted with nozzle-dispersers, the function of which is to regulate

  distributing the flows and spraying the water to be cooled into fine droplets.

  The flow rate of a nozzle is given by the classical expression q = KS '2 g H with q = water flow S = section of the nozzle K = necking coefficient g = acceleration of gravity H = load on l '' nozzle (water pressure) In a standard device, when the flow increases, the required load increases in proportion to the square of the flow. Thus, if we double the flow, the water load is multiplied by four. The distribution tubes and the nozzle-dispersers are then subjected to high stresses detrimental to their resistance over time, and which can cause the plastic dispersers of which the nozzle-dispersers are made to rupture. In this event, water jets are obtained whose pressure is four times higher, which gradually deteriorate the body

  heat exchange located immediately below the disperser nozzles.

  To limit this risk and also that of water freezing when the air temperature is below O C, it has already been proposed to double the distribution network by an auxiliary distribution network, which is not

  supplied only in the event of an overload or overpressure on the first network.

  However, such an embodiment has the disadvantages of making the entire installation particularly expensive, and of operating only by

  strokes, from predetermined thresholds.

  The object of the invention is to provide a liquid distribution network arranged so as to solve the problem posed without requiring

  the addition of an additional auxiliary network.

  The liquid distribution network for atmospheric refrigerant according to the invention is characterized in that a part of the tubes is provided with means for putting these tubes practically out of the liquid circuit at the nominal liquid flow rate, and for using them from the appearance of an overhead above

nominal flow.

  Thus at the nominal liquid distribution flow rate, this flows essentially in the tubes not provided with the aforementioned means, which however allow a small part of the flow rate to flow through the tubes fitted

said means.

  In addition, the ends of the tubes opposite the tank

  or collector are connected together by a pipe.

  According to one embodiment, in which the network comprises an open pit, the aforementioned means comprise one end of said tubes bent in a beak and oriented upwards, as well as a nozzle arranged at the base of this bent end; therefore at the nominal flow rate the corresponding tube is supplied with fluid by the nozzle with a very low flow rate, while at a higher flow rate of a predetermined value, it can also be

  fed by the opening of the bent end.

  This arrangement advantageously replaces, in accordance with the invention, the conventional "rake" arrangement with tubes connected at their ends only by the tank or the collector, the opposite ends being free. Such a liquid distribution network, in particular of hot water, can accept and correctly distribute, gradually, quantities of liquid which can reach up to twice the nominal flow

  without increasing the pressures prohibitively.

  Other features and advantages of the invention will become apparent from

  during the description which follows, with reference to the accompanying drawings

  which illustrate several embodiments thereof by way of examples not

limiting.

  Figure 1 is a schematic perspective view of a first embodiment of the liquid distribution network for

  atmospheric refrigerant according to the invention.

  Figures 2 and 3 are schematic elevational views

  similar to Figure 1 illustrating its mode of operation.

  FIG. 4 is a half-cross sectional partial elevation view of the collecting tank of a distribution network of the open pit type, as well as of a corresponding embodiment of the means of

  deactivation of certain tubes in this network.

  Figure 5 is a schematic top view of the network of

  distribution according to the embodiment of FIG. 4.

  Figure 6 is a partial elevational view of a second embodiment of the means for switching off a tube of a network of the type

with collector.

  Figure 7 is a schematic top view of the network of

  distribution corresponding to figure 6.

  Figures 8 and 9 are schematic plan views of two other possible embodiments of the distribution network according to the invention. The distribution network shown in Figures 1 to 3 is intended for the distribution of liquid, in particular hot water, for refrigerants

  atmospheres used in certain industrial installations.

  This network includes a set of tubes 1, 2, 3, 4, 5 ... parallel to each other and substantially horizontal, connected at one of their ends by a manifold or tank 6 for supplying liquid. The tubes 1, 2 ... are equipped with "nozzles-dispersers" or more simply "dispersers"

  7 of liquid, for example of the shower head type.

  A part of the tubes 1 .... 5 .... for example one in two, is provided with means 8 schematically shown, making it possible to put the corresponding tubes 2, 4 ... practically out of the liquid circuit when the latter is supplied at nominal flow rate, only the other tubes 1, 3, 5 ... not equipped with the means 8, then being supplied. Means 8, including modes of

  realization will be described below, are arranged to not allow the feeding-

  tion of the corresponding tubes 2, 4 ... in liquid only if exceeded

  a determined flow threshold above the nominal flow.

  In addition, the ends of the tubes 1, 2, 3, 4, 5 ...

  opposite the tank or collector 6 are connected together by a pipe-

2 0 tion 9.

  During normal operation, at nominal liquid flow rate, the height of liquid in tank 6 (or the pressure in manifold 6) is less than a height H. Each tube 1, 3, 5 ... is normally supplied with liquid while the tubes 2, 4 ... equipped with the means 8 are supplied only via a member of the means 8 ensuring a throttling of the flow. The small amount of corresponding liquid flowing in the tubes 2, 4 ... makes it possible to supply the dispersers 7 only on a section ED (Figures 1 and 2) while the other tubes such as 1, are supplied normally . Therefore, the quantity of liquid received in these tubes (arrow F in Figure 1) makes it possible to supply not only the entire corresponding length AB of the tube 1 ... but also the connecting part BC between the tubes 1, 2 etc and the sections such as CD of tubes 2 .... equipped with means 8, as indicated by the arrows. When the liquid flow rate increases, the height of liquid in the tank 6 (or the pressure in the manifold 6) becomes greater than the height H. The tubes 2, 4 ... can then be supplied by means 8 which come into action, which authorizes a much greater flow rate in the tubes 2, 4 ... making it possible to supply sections ED 'of length greater than ED. Correlatively the corresponding tube 1, 3 ... feeds a section

  ABCD 'smaller than the initial section ABCD (Figures 2 and 3).

  Such a liquid distribution network can accept and appropriately distribute water flows much higher than the nominal flow, and this in

  using the same single network, without an auxiliary network.

  FIG. 4 shows a first possible embodiment of the aforementioned means 8, adapted to a network of the open-collector type 11. In this network, part of the tubes, for example one in two or one in three, has bent ends 12 in the shape of a beak and oriented upwards, the elbow being substantially at right angles and extending over a height H. A nozzle 13 consisting of a small diameter hole is formed at the base of the bent end 12 and opens into

  the corresponding horizontal tube 2, 4 ...

  At the nominal flow rate (level N1 of the liquid in the tank 11), the corresponding tube 2 (4 ...) is supplied with liquid at a low flow rate, by the nozzle 13, the other tubes, devoid of the spouts 12, being supplied in liquid at nominal flow. On the other hand when the flow rate increases so that the level in the tank 11 reaches and exceeds that of the upper end of the elbow or spout 12 (maximum level N2), the liquid enters the elbow 12 and pours into the tube 2 (4 ...). This can make it possible to increase the flow rate up to approximately twice the nominal flow rate, without causing annoying overpressure in the network, therefore without risking damaging the dispersers 7. As a variant, the constriction at the base of the spouts 12 can be achieved by several nozzles such as 13, or else with holes, or slots or bevels. This or these nozzles can also be fitted with rings

adjustment (not shown).

  Alternatively also the upper opening of the spouts 12 can

  be bevelled as shown in dashed lines referenced 14.

  The distribution network corresponding to the embodiment of

  Figure 4 is shown in Figure 5.

  In the second embodiment, illustrated in FIGS. 6 and 7, the distribution network is of the type with closed tubular collector 15. The means for switching off a part of the tubes 1 ... 5 ... include, for each of the tubes concerned, for example a tube (2, 4, 10) on two a tubular stock 16 arranged in an inverted U between the associated tube 2 (4 ...) and the manifold 15, and connected to them this. The butt 16 is supplemented at its base by a constriction 17 connecting the ends of the stick between them

  as well as tube 2 (4 ...) and manifold 15.

  At nominal flow rate, the liquid pressure in the manifold 15 is not sufficient for this liquid to pass through the butt 16. A small fraction of this liquid therefore flows through the throttles 17 in the tubes 2 (4 ...) , while the other tubes 1, 3, 5 are normally supplied. When the

  pressure in manifold 15 exceeds a predetermined value, corresponding

  at the height H of FIGS. 1 and 4, the liquid penetrates into the stock 16 which it crosses, to then flow into the corresponding tube 2, 4 ... This system of stock 16 and nozzle 17 therefore makes it possible, as the device of FIG. 4, to cope with an increase in the supply rate of the network which can reach approximately twice the nominal rate, without repercussions

annoying on the network.

  In the variant embodiment illustrated in FIG. 8, the tubes 1, 2 ... are connected two by two by their ends opposite to the manifold or supply nozzle 6: are connected together by a pipe 16 the ends of the tubes 1, 2, then of the tubes 3 and 4, 5 and 10 ..., a tube on two of each of these pairs that can be provided with the means described above of

liquid shutdown.

  In the embodiment of Figure 9, the ends of the tubes

  are connected three by three: thus are connected to each other by a pipe-

  tion 17 the ends of the tubes 1, 2, 3, then the tubes 2, 3, 4 etc, at least one of these groups of three tubes being provided with the aforementioned means of setting

out of the liquid circuit.

  In addition to the advantages mentioned above, the invention presents that of ensuring correct operation of the refrigerant (distribution of liquid) on a regular basis as a function of variations in flow rate, and not in a "brutal" manner as soon as a level of predetermined water is reached (or a predetermined water overpressure value), as in the case of the previously mentioned known embodiment with an auxiliary network doubling the main network.

Claims (7)

  1. Liquid distribution network for atmospheric refrigerant   that, comprising a set of tubes (1, 2, 3, ...) parallel to each other and substantially horizontal, connected at one of their ends by a manifold or tank (6) for supplying liquid, and equipped with liquid dispersers (7), characterized in that a part (2, 4 ..) of the tubes is provided with means for putting these tubes practically out of liquid circuit at the nominal liquid flow (N1), and for using them from the appearance of an overflow above the nominal flow. 2. Network according to claim 1, characterized in that the ends of the tubes (1, 2, ..) opposite the tank or collector (6) are   connected together by a pipe (9).   3. Network according to claim 2, comprising a tank (11) in the open, characterized in that said means comprise one end of said tubes (2, 4 ...) bent in the shape of a beak (12) and oriented upwards. , as well as a nozzle (13) arranged at the base of this bent end, so that at the nominal flow (N1) the corresponding tube is supplied with liquid by the nozzle and that at a higher flow it can besides being powered by   the opening of the angled end as soon as this overflow is sufficient (N2).   4. Network according to claim 3, characterized in that   the bent end is bevelled (14).   5. Network according to claim 2, comprising a closed tubular collector (72) (15), characterized in that said means comprise a tubular butt (16) arranged in an inverted U between the tube (2, 4 ...) and the manifold and connected thereto, as well as a throttle (17) connecting the   ends of the stock at the level of the tube and the collector.   6. Network according to claim 1, characterized in that the ends of the tubes (1, 2 ...) opposite the tank or collector (6) are connected at the rate of two consecutive tubes (1-2, 3-4 ,. ..) or three tubes consecutive (1-2-3, 4-5-10, ...).   7. Network according to one of claims 5 and 6, characterized in that   that the tubes (2,4 ...) fitted with said crosses (16) for switching off the liquid at nominal flow rate and the other tubes (1,3 ...) are superimposed, the tubes   provided with the brackets being arranged in the lower plane.