Air humidifier with boil-over protection

Abstract

An air humidifier for generating humidified breathing air for a patient includes a boiling pot for receiving a defined water volume. The air humidifier has a partition, the partition having at least one perforation. The partition with perforation is designed to be arranged above a water surface of the defined water volume in the boiling pot.

Claims

1. An air humidifier for generating humidified breathing air for a patient, the air humidifier comprising: a housing comprising a boiling pot with a water feed inlet, the boiling pot receiving a defined water volume with a water surface and with an upper housing portion defining a vapor space situated adjacent to and above the boiling pot and with a vapor space vapor outlet, wherein during operation only fluid from the boiling pot is present in the vapor space and only fluid released from the vapor space passes through the vapor outlet; and a partition having at least one perforation allowing liquid and vapor to pass through the at least one perforation from below the partition to above the partition, the partition being arranged above the water surface of the defined water volume in the boiling pot and below at least a portion of the vapor space and below the vapor outlet, wherein the partition is funnel-shaped.

2. An air humidifier in accordance with claim 1, wherein the at least one perforation has an area of 50 mm.sup.2 to 120 mm.sup.2.

3. An air humidifier in accordance with claim 1, wherein the at least one perforation has an area of 70 mm.sup.2 to 90 mm.sup.2.

4. An air humidifier in accordance with claim 1, wherein the at least one perforation is round and has a diameter of 8 mm to 12 mm.

5. An air humidifier in accordance with claim 1, wherein the at least one perforation is round and has a diameter of 9.5 mm to 10.5 mm.

6. An air humidifier in accordance with claim 1, further comprising a heating element connected to the housing for heating the defined water volume in the boiling pot.

7. An air humidifier in accordance with claim 1, further comprising a water tank with a water feed operatively connected to the water feed inlet and feeding fresh water to the boiling pot and maintaining an essentially constant said defined water volume, wherein the boiling pot has a mark or indication for determining the defined water volume.

8. An incubator comprising: an air humidifier for generating humidified breathing air for a patient, the air humidifier comprising a housing comprising a boiling pot with a water feed inlet, the boiling pot receiving a defined water volume with a water surface and with an upper housing portion defining a vapor space situated adjacent to and above the boiling pot and with a vapor space vapor outlet, wherein during operation only fluid from the boiling pot is present in the vapor space and only fluid released from the vapor space passes through the vapor outlet and a partition with at least one perforation allowing liquid fluid and gaseous fluid passage through the at least one perforation from below the partition to above the partition, the partition being arranged above the water surface of the defined water volume in the boiling pot and below at least a portion of the vapor space and below the vapor outlet; a patient space with a reclining surface for a patient for accommodating the patient; and a breathing air feed means for feeding the humidified breathing air to the patient space, the breathing air feed means comprising a gas line with an environmental air inlet and a humidified air outlet and further comprising a blower for moving gas within the gas line in a direction from the air inlet toward the humidified air outlet, the vapor outlet being connected to the gas line between the air inlet and the humidified air outlet to feed vapor from the vapor space into the gas line to add vapor to environmental air to form the humidified air.

9. An incubator in accordance with claim 8, wherein the at least one perforation has an area of 50 mm.sup.2 to 120 mm.sup.2.

10. An incubator in accordance with claim 8, wherein the at least one perforation is round and has a diameter of 8 mm to 12 mm.

11. An incubator in accordance with claim 8, wherein the partition is funnel-shaped.

12. An incubator in accordance with claim 8, further comprising a heating element connected to the housing for heating the defined water volume in the boiling pot.

13. An incubator in accordance with claim 8, further comprising a water tank with a water feed operatively connected to the water feed inlet and feeding fresh water to the boiling pot and maintaining an essentially constant said defined water volume, wherein the boiling pot has a mark or indication for determining the defined water volume.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic view showing an incubator with an air humidifier according to one embodiment of the present invention;

(2) FIG. 2a is an exploded perspective view showing an embodiment of an air humidifier according to the present invention;

(3) FIG. 2b is a perspective view showing the embodiment of an air humidifier according to FIG. 2a with a housing part (spout) shown as a transparent housing part;

(4) FIG. 2c is a sectional view showing the embodiment of an air humidifier according to FIG. 2b with the housing part (spout) not shown as a transparent housing part;

(5) FIG. 2d is another sectional view showing the embodiment of an air humidifier according to FIG. 2b with the housing part (spout) not shown as a transparent housing part;

(6) FIG. 3a is a sectional view of another embodiment of an air humidifier according to the present invention showing a mode of operation;

(7) FIG. 3b is a sectional view of the embodiment of FIG. 3a, showing another mode of operation;

(8) FIG. 3c is a sectional view of the embodiment of FIG. 3a, showing another mode of operation; and

(9) FIG. 3d is a sectional view of the embodiment of FIG. 3a, showing another mode of operation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(10) Referring to the drawings in particular, FIG. 1 shows an embodiment of an incubator, which has an air humidifier according to an embodiment of the present invention. A reclining surface 1 for a patient is arranged under the incubator hood 2. The interior space of the incubator is supplied by a fresh gas stream 3 with fresh gas or breathing air for the patient. To ensure a sufficient inflow of oxygen under the incubator hood 2, an oxygen sensor 5 measures the oxygen content in the interior space of the incubator and sends the measurement result to an oxygen regulator 51. The oxygen regulator 51 actuates the oxygen dispenser 7, which regulates the content of oxygen, which is fed to the system via the oxygen concentrator 12.

(11) The fresh gas stream 3 fed into the interior space of the incubator has a portion of the gas stream sent through the oxygen concentrator 12 and the oxygen dispenser 7 as well as a portion of a fresh air stream 13, which are delivered through a microorganism filter 11 and a blower 10. The combined fresh gas stream 3 is sent subsequently through a heater 6, which heats the fresh gas stream such as this is measured by the temperature sensor 4 as being necessary and regulated by the temperature regulator 41.

(12) The fresh gas stream enriched with oxygen, which has passed through the heater 6, is subsequently enriched with moisture before it is sent into the interior space of the incubator. A moistener 9 (which is shown schematically in FIG. 1 and is also called air humidifier in the present application), which is connected with a water tank 8, from which fresh water is sent into the boiling pot evaporating water vapor, is provided for humidifying the breathing air.

(13) FIGS. 2a through 2d show views of an embodiment of an air humidifier according to the present invention. FIG. 2a shows an embodiment of an air humidifier 90 before mounting and FIG. 2b shows the embodiment of an air humidifier 90 after mounting, with a housing part 95 being shown as a transparent housing part in FIG. 2b in order to make a view into the interior of the air humidifier 90 possible. FIG. 2c shows a cross section through the air humidifier 90 according to FIG. 2b with non-transparent housing part 95. FIG. 2d shows another perspective view of a cross section through the air humidifier 90 according to FIG. 2b with non-transparent housing part 95.

(14) The air humidifier 90 (which corresponds, for example, to the moistener 9) has a boiling pot (boiling pot housing part) 92 for receiving a defined water volume. A water tank 8 feeds fresh water to the boiling pot 92, so that an essentially constant defined water volume 91 (not shown in FIG. 2) is always present in the boiling pot 92. An especially hygienic humidification of the breathing air is achieved by feeding fresh water from the water tank 8, which is boiled off at first in the boiling pot 92 before it is fed as vapor to the breathing air. A partition with aperture 93 is arranged above the water surface of the water volume 91. In one embodiment, the boiling pot has, for example, a diameter of 35 mm and the defined water volume 91 equals 10 cm3. The boiling pot 92 adjoins a vapor space housing part (spout housing part) 95, which can be connected with a respiration system or an incubator. The housing part 95 has a vapor outlet 98, through which the water vapor can be fed to the respiration system or incubator.

(15) The air humidifier 90 has, furthermore, a heating element 94, which is arranged on one side of the boiling pot 92 and which heats the water contained in this. The partition with aperture 93 is fixed to the inner wall of the boiling pot 92 by means of between projections 99 on the inner wall of the boiling pot, which act as fixing means. The partition with aperture 93 of the embodiment shown in FIG. 2 is funnel-shaped and has a central perforation 97.

(16) FIGS. 3a through 3d show another embodiment of an air humidifier according to the present invention, which differs from the embodiment according to FIG. 2 essentially in that the partition with aperture 93 is flat (i.e., not funnel-shaped). Insofar as the features of the air humidifier 93 according to FIG. 3 are essentially identical to those in FIG. 2, reference is made to the above description.

(17) It will be explained blow on the basis of FIGS. 3a through 3d how an embodiment of a partition with aperture prevents or reduces foaming over or boiling over.

(18) FIG. 3a shows a boiling pot 92 with gently boiling water 91 and a low level of contamination. The heating output of the heating element 94, which is designed, for example, as a cartridge type heater, leads to the formation of vapor bubbles, as is indicated in FIG. 3a.

(19) More foam or vapor bubbles will gradually form due to further heating of the eater 91, and they will eventually escape through the diaphragm opening; this is shown in FIG. 3b.

(20) The bubbles passing through the perforation 97 of the partition with aperture 93 will cool down above the partition with aperture 93 and come to lie as a thin film of water on the partition with aperture 93. If the perforation 97 of the partition with aperture 93 is closed by the water layer formed, the boiling process in the lower part of the boiling pot 92 will come to an end in a short time until the water of this water layer has flowed back into the lower part of the boiling pot 92. The formation of rising bubbles and of the water layer begins anew. A pulse-like build-up and subsiding can be recognized.

(21) By increasing the heating output, the formation of vapor bubbles and vapor foam is increased such that a closed water layer can eventually form on the partition with aperture 93, and this water layer cannot flow back completely into the lower part of the boiling pot 92 any longer, as this is shown in FIGS. 3c and 3d. As a consequence, the pressure rises under the partition with aperture 93, which can also be measured as an increase in the boiling point. Bubbles will continue to rise through the water layer with the increased pressure, but these bubbles will burst in this [water layer]. Foaming above the water layer is thus prevented or reduced by the slightly cooled, no longer boiling water.

(22) While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.

(23) TABLE-US-00001 APPENDIX List of Reference Numbers 1 Reclining surface 2 Incubator hood 3 Fresh gas stream 4 Temperature sensor 5 Oxygen sensor 6 Heater 7 Oxygen dispenser 8 Water tank 9 Moistener 10 Blower 11 Microorganism filter 12 Oxygen concentrator 13 Fresh air stream 41 Temperature regulator 51 Oxygen regulator 90 Air humidifier 91 Water volume 92 Boiling pot 93 Partition with aperture 94 Heating element 95 Housing part 96 Mark 97 Perforation/aperture/opening 98 Vapor outlet 99 Fixing means