Abstract:
A reservoir of the device supports, in its upper portion, a profiled flange forming a handling apparatus for the device and a trough to collect and discharge, via an opening, the water of condensation forming on a vaporization coil. The coil has turns of changing diameters, supported by support combs on the trough and enclosed in a cover provided with peripheral and upper air openings. The cover includes an element for securing a receptacle that directly coacts, by gravity, condensates.

Description:
FIELD OF THE INVENTION 
     The present invention relates to transportable devices for storing and supplying cryogenic fluid, of the type comprising a storage reservoir for the fluid in liquid phase, a supply circuit for the fluid in gaseous phase to at least one user station, arranged on the upper portion of the reservoir and comprising at least one vaporization coil, and handling the device. 
     BACKGROUND OF THE INVENTION 
     A device of this type is described in U.S. Pat. No. 4,211,086 (Beatrice Foods Company). In this document, the transport and handling of the device are ensured by pivoted handles fixed on the sidewalls of the reservoir, which does not permit correct nor easy handling by the user. Moreover, the supply circuit for the fluid in gaseous phase is enclosed in a closed housing constituted by the sealed assembly of a cover substantially free from openings and a base with a T-shaped profile welded on the reservoir. Such an arrangement does not permit suitable heat exchange nor the evacuation of water vapor accumulating in the cover, particularly because of the cold vaporization coil. 
     More recently, there have been proposed analogous devices with a profiled base support for the cover connected by a tube projecting outwardly from the cover to a small bottle suspended laterally from the reservoir and receiving the condensate accumulating in the base, in an inconvenient and hardly optimum arrangement. 
     SUMMARY OF THE INVENTION 
     The present invention has for its object to provide an improved device permitting, simply and effectively, at low cost and offering a great versatility, the collection and accumulation with high efficiency of the condensates in the cover whilst greatly facilitating handling of the device and optimizing the performance of the vaporization coil. 
     To do this, according to one characteristic of the invention, the handling means of the device are at least in part constituted by a profiled flange mounted on the reservoir, forming a trough for the collection and evacuation of the condensate and provided with an outlet opening for the condensate. 
     According to other characteristics of the invention: 
     the flange comprises a downwardly curved external portion forming a handrail for gripping and handling, connecting to a central mounting portion on the reservoir by an intermediate upwardly curved portion and provided with at least one hollow radial passage, thereby permitting free circulation of liquid between the central portion and the external portion. 
     at least one portion of the circuit is sheltered in a pierced cover, comprising typically a lower end in the form of a flared skirt that comes into bearing against the periphery of the flange, thereby enclosing the handrail, the skirt-shaped portion comprising typically angular aeration openings angularly spaced about the cover. 
     the cover comprises means for attaching a receptacle for collecting condensate, having typically a condensate reception trough extending below the evacuation opening of the flange in the assembled arrangement. 
     the cryogenic is medical oxygen, typically for home oxygen therapy treatments. 
     The present invention also relates to devices for vaporizing a cryogenic liquid suitable for transportable storage and supply devices for cryogenic fluid defined above, more particularly atmospheric devices for vaporization and reheating of a cryogenic liquid containing oxygen for oxygen therapy, of the type comprising a coil constituted by several coaxial windings with ordinarily a substantially vertical axis, having a first end connected to a source of cryogenic liquid and a second end connectable to a user circuit, for example for the supply of a respiratory mask. 
     In known devices of this type, as described in U.S. Pat. No. 4,211,086 mentioned above, the coil comprises superposed windings of substantially constant diameter and of an axial spacing which is also substantially constant. These devices have the drawback that, in use, the condensation of water which inevitably takes place along the coil, is accompanied by the formation of drops of water falling downwardly of the coil, which is to say onto the colder turns, accumulating on these lower turns in the form of layers of ice which greatly reduce the heat exchange performance of the coil and require in practice an increased length, hence an increase in the overall volume. This phenomenon of condensation and deposit of ice is further increased when the coil is enclosed in a cover capping the cryogenic gas reservoir constituting said source. 
     The present invention also has for its object to provide a simple vaporization device, which will be reliable and inexpensive, eliminating the above problems and permitting guaranteeing, in a compact form easily disposable in an envelope, by a vaporization output that is substantially constant with time. 
     To do this, according to one characteristic of the invention, at least the two lower turns of the coil have a greater diameter than the other turns. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other characteristics and advantages of the invention will become apparent from the following description of one embodiment, given by way of non-limiting example, with respect to the accompanying drawings, in which: 
     FIG. 1 is a fragmentary cross-sectional schematic view, of the upper portion of a device according to the invention. 
     FIG. 2 shows on a larger scale a vaporization coil according to the invention. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     In the drawings, there will be seen the upper conical portion of a reservoir  1  for cryogenic liquid under pressure, typically liquid oxygen, with a vertical axis. 
     At its upper end, the reservoir comprises a filling and withdrawing head  2  for gas, comprising particularly a vertical securement rod  3 , with a screw  22 , a cover or cap  4 , as will be further seen. To the head  2  is connected the upstream end  31  of a vaporization coil  5 , preferably coaxial with the reservoir  1  and whose downstream end  32  is connected, via a valve/expander block  6 , to a gas outlet  7  for connection to a user circuit, typically a breathing circuit of a patient (not shown). Preferably, as will be seen later, at least the base of the coil  5  comprises windings that are spaced axially farther one from another than the upper windings and of a diameter increasing downwardly, to prevent icing by the drops of condensation water appearing on the least cold turns of the coil and dripping downwardly by gravity. 
     According to one aspect of the invention, these drops of condensation are collected in an angular flange structure, generally indicated by the reference  8 , welded at its central portion on the conical wall  23  of the reservoir  1  and having, in transverse cross-section, from this central portion, a profile forming successively an upwardly curved region  9  then a peripheral downwardly curved region  10  forming a circular gripping handrail, the hollow of the curved portion  9  permitting receiving the fingers of the hand of the handler. At one point on the handrail there is provided, in the bottom of the peripheral curved portion  10 , a drain opening  11  permitting evacuating by gravity the condensed water collected in the flange  8 . The opening  11  is preferably formed at the lowest point of the flange  8  which has, for this purpose, a slight declivity in the direction toward the opening  11 . A substantial portion of the condensates dripping into the central portion of the flange  8 , there is provided at least at the level of the opening  11 , at least one radial valley  12  locally interrupting the intermediate curved portion  9  to permit free communication of the liquid on opposite sides of this latter. 
     In a preferred embodiment, as shown, the coil  5  is supported by support combs  13  typically of plastic material, whose lower portion is mounted preferably by simple clipping on the intermediate curved portion  9 , provided typically, in its upper portion, with openings for this purpose. 
     According to one aspect of the invention, the cover  4  comprises an upper transverse wall  14  serving for the securement of the cover  4  on the reservoir  1  via the vertical pillar  3 , and the peripheral portion in the form of a downwardly flared skirt  15  whose lower edge bears on the peripheral edge of the curved portion  10  of the flange  8 . To cause atmospheric vaporization with optimum heat exchange, the skirt  15  comprises, typically over most of its perimeter, a series of vertical parallel slots  16  and the upper wall  14  comprises, adjacent its periphery, a series of radial slots  17 . 
     According to one aspect of the invention, the cover  4  forms laterally a housing defining a recess  24  to receive at least a portion of a humidifying receptacle indicated in broken lines at  18 , which connects to the outlet channel  7 . Preferably, the recess  24  comprises at its base means  19  for demountable securement, preferably of the type with a slide, of a removal receptacle  20  for receiving condensate, comprising a trough  21  extending, in the attached position of the receptacle  20 , below the outlet opening  11 . 
     The cover  4  and the receptacle  20  are preferably made of a rigid plastic material. The reservoir  1  preferably comprises, at its base, rollers facilitating its movement. 
     As is better seen in FIG. 2, the coil  5 , constituted by winding a metal tube which is a good heat conductor, conventionally of aluminum, on a profile mandrel, is divided into an upper portion  36  comprising at least two, typically six or seven adjacent turns and a substantially constant diameter, and a lower portion  37 , partially surrounding the upper end of the reservoir  1 , comprising at least two, in practice three or four turns, spaced farther axially one from the other and of downwardly increasing diameters, the lowermost complete turn having the greatest diameter and the uppermost complete turn having a diameter slightly greater than that of the turns of the upper portion  36 . 
     In this way, the drops of water of condensation appearing on the turns that are the least cold of the upper portion  36 , flow and drip downwardly without falling, or very little, on the coldest turns of the lower portion  37 , to accumulate in the trough formed by the flange  8  from which the water is evacuated toward the condensate collection receptacle  20 . Moreover, the axial and radial spacing of the lower turns guarantees a greatly improved heat exchange with the surrounding atmosphere. 
     Preferably, as mentioned above, the coil  5  is supported by support combs  13  that are angularly spaced, shaped to correspond to the profile of the coil  5 , and externally comprising a series of recesses  40  arranged to receive the different turns of the coil  5 . The support combs  13 , of a material of low heat conductivity, typically of a plastic material, are preferably mounted at their base by clipping  41  in the structure of the flange forming the trough  8 . Preferably, the upper turns  36  of the coil  5  are maintained in position, as are the support combs  13 , by spacer combs  42  of reduced height. 
     Although the invention has been described in connection with a particular embodiment, it is not thereby limited but is adaptable for modifications and variations which will be apparent to one skilled in the art, within the scope of the following claims.