GB1579177A - Thermostaticallycontrolled enclosure for producing a liquid at a preselected temperature - Google Patents

Description

(54) THERMOSTATICALLY-CONTROLLED ENCLOSURE FOR PRODUCING A LIQUID AT A PRESELECTED TEMPERATURE (71) We, E. DAMOND S.A. COM PAGNIE AUXILIAIRE D'ENTER PRISES ELECTROMECANIQUES, a French body corporate of 39 Rue Francois Arago, 93100-MONTREUIL-SOUS-BOIS, France, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates generally to apparatus for providing a liquid. most often water, at a preselected temperature.

Numerous apparatus of this type are known in which the liquid is brought to a preselected temperature before it is dispensed or distributed. In such known apparatus the water is heated to a desired temperature for use as it is or after mixing with water at ambient temperature to lower the temperature of the heated water. Such prior art apparatus need not be described in greater detail herein.

When such apparatus are employed in laboratories and hospitals. for use in treating a patient or in research work. it is necessary to provide a liquid satisfying two essential conditions. i.e. a degree of purity and temperature accuracy; to the present day it has been common practice to have two liquid reservoirs or tanks and a sterilisation unit for distribution circuits carrying a mixture from the reservoirs.

It will be readily understood that such apparatus are of complicated construction and operation and furthermore they are not entirely satisfactory, namely as to the accuracy of the temperature at which the liquid is to be dispensed.

An object of the invention is the provision of apparatus which overcomes the drawbacks briefly discussed above.

The present invention provides a thermostatically-controlled enclosure assembly for dispensing a liquid at a preselected temperature, comprising a first, heat-insulating tank and a second tank disposed inside the first tank and defining a space therebetween, the first tank having an inlet and an outlet adapted to circulate a heat transfer fluid through the space, heating means associated with the first tank for heating heat transfer fluid in the space. the second tank having an inlet adapted to be connected to a source of liquid at a predetermined degree of purity to be treated and an outlet through which liquid may be disposed at the preselected temperature and with'a predetermined degree of purity. the second tank including an elongated hollow member extending through the second tank and housing heating means for liquid in the second tank and theremostatic control means for controlling the temperature in the second tank.

Such a thermostaticallv-controlled enclosure assembly has a particularly interesting, though not an exclusive. application in "artificial kidneys" for brining the temperature of the rinsing liquid to that of the patient is blood to be dialysed. in which the rinsing liquid to be dispensed form a suitable filtration device upstream of the enclosure assembly is distributed to the dialyser through cascaded sterilisation zones.

With this in mind. and according to the invention there is also provided an installation comprising. in combination, with such a thermostaticallv-controlled enclosure assembly, a steam generator adapted. when appropriate. to sterilise an intermediate part of the installation and said second inner tank simultaneously therewith.

For this purpose the steam generator is disposed upstream of the thermostaticallycontrolled enclosure assembly: the steam generator. supplied with filtered water. is in communication. through suitable lines and valves. with part of the installation between a three-way valve and the second tank.

In this way. the part of the installation located between the filtration zone and the three-way valve may be sterilised with stream, i.e. in the embodiment, the second, inner tank, the tubes, filtration devices, and perhaps other elements located in this part of the installation.

Preferably, between the three-way valve and the artificial kidney there is provided a secondary sterilisation zone.

In this use of the thermostaticallycontrolled enclosure assembly an advantage resides in various parts of the installation may be cleaned and sterilised by flowing steam produced from the liquid, that is, water, which grcatly simplifies the various operations. Accordingly the equipment is simple, easy to tise, totally safe in operation, since the operations are limited, thereby substantially eliminating chances of error.

Another advantage of the preferred embodiment resides in the fact that virtually unlimited quantities of water are provided for the artificial kidney, the water being at preciscly 37"C. with only minute variations which in any case arc negligible. This result is made possible by the structure of the thermostatically-controlled enclosure assembly and the thermostatic control sytem per se which docs not form part of the invention and therefore need not be described here in detail.

Other features and advantages of the invention will be brought out in the description which follows. given by way of example. with preference to the accompanying drawings. in which: Fig I is a partlv cut-away perspective view of a thermostatically-controlled enclosure asscmbly: and Figure 2 is a diigrammatic view of an installation of which tilC the thclmostaticallv- controlled enclosure assembly is an integral part.

In the preferred embodiment of the ther mostatically-controllcd enclosure assembly illustrated in Figure 1. the enclosure assembly comprises a first outer tank l() of generally parallelpipedic or boxlike shape of double wall Il . 12 construction with a heat-insulating filler 13 therein.

The outer hcat-insulatcd tank I() is provided. in its lower part ind along a lateral side. with an inlet 15 for incoming heat transfer fluid and its upper part with an outlet I 6 for outgoing the heat transfer liquid aftcr circulating in the first tank.

A second tank. designated generally hy preference numeral 17. is disposed inside the first tank 1(). The second tank is of generally parallelpipcdic or hoxlike shape hut of course is smaller than the outer tank It) so as to define a space V between the inner wall of the outer tank and the outer surface of the inner tank.

The second tank 17 has an inlet 22 for connection to a source of liquid to be treated, e.g. rinsing water with a predetermined degree of purity, in its lower part and an outlet 23 for treated liquid in its upper part. The second tank 17 is supported and held stationary inside the outer tank 10 by cross bars 24.

A hollow member 25 extends through the inner tank 17 and is sealingly joined thereto by welds along the end walls 26 of the inner tank 17. The hollow member 25 houses a heating tube 28 which comprises heating means and a thermostatic control means 29 known per se which is adapted to control the temperature of the treated liquid in the inner tank 17 at the desired preselected temperature for dispensing.

The foregoing heating tube 28 and the thermostatic control means 29 are electrically insulated from each other. The heating tube 28 and the thermostatic control means 29 extend through the space V between the inner and outer tanks 17 and 10 and out of the enclosure through the end wall 30 of the outer tank 10.

The inner tank 17 has, in addition, on its outer wall surface a series of longitudinal fins 31 improving heat transfer, while the hollow member 25 has along its inner wall a series of longitudinal fins 32 for the same purpose.

In the thermostaticallv controlled enclosure assembly thus described the liquid to be treated inside the inner tank may be brought to the desired temperature with great accuracy; the heating tube 2X being adapted to bring the liquid in the inner tank 17 up to the desired temperature whereas the heating tubes 2(). 21 are intended to bring the heat transfer fluid in the space V to a constant temperature and keep it at this temperature.

The heating tube arrangement and the heat insulation of the outer tank. together with the internal structure of the assembly, permit a liquid to be obtained from the inner tank at a desired temperature.

There are obviously numerous applications for the present thermostaticallycontrolled enclosure assembly.

First, such an enclosure assembly may provide a liquid to be dispensed. e.g. water, at a preselected temperature and the purity is not changed on passage through the assembly.

The thermostaticallv-controlled enclosure assembly is advantageously mounted in series. as shown in Figure 2. with a steam generator 35 disposed downstream of a filtration device. designated generally by numeral 36.

The steam generator comprises a liquid inlet 37 and steam outlet 3X and draining means 39. The steam outlet 38 may be brought into communication with a circuit C through valves 42 and 43, the circuit C being arranged downstream of the thermostatically-controlled enclosure assembly and not in communication with the inner tank 17 thereof; or it may be brought into communication with the second tank through lines 44 and 22.

As for the second tank 17, it may be filled with filtered water via valve 45 disposed in a line 46 connected to the outlet of the filtration device 36.

The distribution circuit C and filter devices 50 and 51, are disposed downstream of the thermostatically-controlled enclosure assembly, will not be described in detail. It will simply be noted that the distribution circuit advantageously be equipped with filtration means and an additional sterilisation circuit which are known per se.

It is understood that the thermostaticallycontrolled enclosure assembly according to the invention may have several functions, depending on whether it is in operation independently of, or in combination with, the steam generator 35. When used independently. the enclosure assembly may dispense a liquid at a preselected temperature and a given degree of purity. When used in combination with a steam generator. the enclosure assembly may also disperse a liquid at a very accurate temperature and a given degree of purity. though before dispensing the liquid. it permits simultaneous sterilisation. with steam. of the inner tank as well as at least part of the installation located downstream of the second inner tank.

WHAT WE CLAIM IS: 1. A thermostatically-controlled enclosure assembly for dispensing a liquid at a preselected temperature. comprising a first.

heat-insulating tank and a second tank disposed inside the first tank and defining a space therebetween. the first tank having an inlet and an outlet adapted to circulate a heat transfer fluid through the space. heating means associated with the first tank for heating heat transfer fluid in the space. the second tank having an inlet adapted to be connected to a source of liquid at a predetermined degree of purity to be treated and an outlet through which liquid may be disposed at the preselected temperature and with a predetermined degree of purity. the second tank including an elongated hollow member extending through the second tank and housing heating means for liquid in the second tank and thermostatic control means for controlling the temperature in the second tank.

2. . An assemblv according to claim I or claim 2. wherein the tanks ire of boxlike configuration : and the heating means associ- ated with the first tink compiises one heat transfer tube disposed in the space between the tanks and the heating means for liquid in the second tank comprises a heat transfer tube.

3. An assembly according to any of the preceding claims, wherein regularly spaced parallel fins are disposed along the exterior of the second, inner, tank.

4. An assembly according to any of the preceding claims. wherein regularly spaced parallel fins are disposed along the interior of the first tank.

5. An installation having a thermostatically-controlled enclosure assembly for dispensing a liquid having a predetermined degree of purity at a preselected temperature according to claim l. further comprising means for selectively connecting the second tank to a steam generator or a treated liquid supply line. said generator being disposed between a filtration means and the assembly.

6. A thermostaticallv-controlled enclosure assembly substantially as described herein with reference to or as illustrated in Figure 1 of the drawing.

7. An installation comprising a thermostatically-controlled enclosure assembly substantially as described herein with reference to or as illusreated in Figures I and 2 of the drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. through valves 42 and 43, the circuit C being arranged downstream of the thermostatically-controlled enclosure assembly and not in communication with the inner tank 17 thereof; or it may be brought into communication with the second tank through lines 44 and 22. As for the second tank 17, it may be filled with filtered water via valve 45 disposed in a line 46 connected to the outlet of the filtration device 36. The distribution circuit C and filter devices 50 and 51, are disposed downstream of the thermostatically-controlled enclosure assembly, will not be described in detail. It will simply be noted that the distribution circuit advantageously be equipped with filtration means and an additional sterilisation circuit which are known per se. It is understood that the thermostaticallycontrolled enclosure assembly according to the invention may have several functions, depending on whether it is in operation independently of, or in combination with, the steam generator 35. When used independently. the enclosure assembly may dispense a liquid at a preselected temperature and a given degree of purity. When used in combination with a steam generator. the enclosure assembly may also disperse a liquid at a very accurate temperature and a given degree of purity. though before dispensing the liquid. it permits simultaneous sterilisation. with steam. of the inner tank as well as at least part of the installation located downstream of the second inner tank. WHAT WE CLAIM IS:

1. A thermostatically-controlled enclosure assembly for dispensing a liquid at a preselected temperature. comprising a first.

heat-insulating tank and a second tank disposed inside the first tank and defining a space therebetween. the first tank having an inlet and an outlet adapted to circulate a heat transfer fluid through the space. heating means associated with the first tank for heating heat transfer fluid in the space. the second tank having an inlet adapted to be connected to a source of liquid at a predetermined degree of purity to be treated and an outlet through which liquid may be disposed at the preselected temperature and with a predetermined degree of purity. the second tank including an elongated hollow member extending through the second tank and housing heating means for liquid in the second tank and thermostatic control means for controlling the temperature in the second tank.

2. . An assemblv according to claim I or claim 2. wherein the tanks ire of boxlike configuration : and the heating means associ- ated with the first tink compiises one heat transfer tube disposed in the space between the tanks and the heating means for liquid in the second tank comprises a heat transfer tube.

3. An assembly according to any of the preceding claims, wherein regularly spaced parallel fins are disposed along the exterior of the second, inner, tank.

4. An assembly according to any of the preceding claims. wherein regularly spaced parallel fins are disposed along the interior of the first tank.

5. An installation having a thermostatically-controlled enclosure assembly for dispensing a liquid having a predetermined degree of purity at a preselected temperature according to claim l. further comprising means for selectively connecting the second tank to a steam generator or a treated liquid supply line. said generator being disposed between a filtration means and the assembly.

6. A thermostaticallv-controlled enclosure assembly substantially as described herein with reference to or as illustrated in Figure 1 of the drawing.

7. An installation comprising a thermostatically-controlled enclosure assembly substantially as described herein with reference to or as illusreated in Figures I and 2 of the drawing.