Heating and humidifying respiratory mask
A light-weight face mask can heat and humidify inhaled air with previously-exhaled air by passing the air through a highly-effective and highly-efficient heat exchanger disposed within the mask. The heat exchanger has a multitude of layers of metallic mesh through which the air passes generally linearly. The warm exhaled air heats the mesh which in turn heats the incoming air before it is inhaled. Moisture from the exhaled air condenses on the relatively-cool heat exchanger and humidifies the incoming air. Inhaled air enters the mask generally upwardly, and exhaled air exits it generally downwardly.
Claims
1. A light-weight respiratory face mask for warming and humidifying inhaled air of a person who can wear the mask, i.e., a wearer, and who has a head, and a face, nose, chin and mouth, efficiently with negligible pressure differential, which comprises:
- (a) an inner flexible shell capable of covering the wearer's face from the nose to the chin, said shell capable of being spaced apart from the wearer's face, and capable of providing an insulating air space between the wearer's face and the mask when the mask is worn, with peripheral edges of the inner shell able to be placed in contact with the wearer's face to form an air seal when the mask is worn;
- (b) a heat exchanger disposed in a pocket in the inner shell located opposite a position which can define the wearer's mouth, and to be in open communication with the wearer's mouth, with the heat exchanger consisting of about 15 to about 50 layers of metallic mesh, and with each of the layers of the metallic mesh having a surface area and a thermal conductivity within each layer of the metallic mesh appropriate to the metallic mesh employed and low thermal conductivity to adjacent layer(s) of the metallic mesh, the layers being provided in a sheetlike arrangement, one layer upon another, and being such that air can flow back and forth across the layered arrangement in a direction from outside layer to inside layer and from inside layer to outside layer in a direction substantially perpendicular to the layers in the mask during breathing by the wearer;
- (c) an outer shell in a position opposite the wearer's mouth when the mask is worn, with the outer shell having edges and joining the inner shell above and on either side of the heat exchanger, and the outer shell spaced apart from the heat exchanger and the inner shell;
- (d) an opening between the inner shell and the outer shell below the heat exchanger to allow entry of air inhaled by the wearer of the mask when the mask is worn and the wearer's head is in an upright position upwardly, and discharge of air exhaled by the wearer of the mask when the mask is worn and the wearer's head is in an upright position downwardly, such that exhaled air can heat the heat exchanger, which in turn can heat the inhaled air,
- with the outer shell, the opening and the heat exchanger being located on the mask so as to be able to reduce a tendency of the heat exchanger to otherwise freeze in cold weather when the mask is worn when snow is falling or blowing.
2. The mask of claim 1, wherein the outer shell protrudes less than about 3 centimeters beyond the wearer's nose.
3. The mask of claim 1, wherein the total surface area of all of the layers of metallic mesh in the heat exchanger is substantially less than about two thousand square centimeters.
4. The mask of claim 1, wherein each layer of the metallic mesh of the heat exchanger has a cross-sectional area of 6 to 24 square centimeters.
5. The mask of claim 4, wherein the thickness of the metallic layers is less than 2.5 centimeters when pressed together.
6. The mask of claim 1, wherein the layers of the metallic mesh are of aluminum or brass.
7. The mask of claim 6, wherein each of the layers of the metallic mesh is of aluminum screening which consists of aluminum wires about 0.025 centimeters in diameter, spaced about 0.14 centimeters apart center to center in one direction and spaced about 0.16 centimeters apart center to center in a direction perpendicular thereto.
9. The mask of claim 1, wherein adjacent layers of metallic mesh are connected along at least one edge.
10. The mask of claim 4, wherein the heat exchanger is centrally located, and the heat exchanger had a width and a height, and the width of the heat exchanger exceeds the height of the heat exchanger.
11. The mask of claim 10, wherein a flexible cavity is provided within the mask for easily and quickly inserting and removing a heat exchanger pack consisting of layers of metallic mesh.
12. The mask of claim 1, having a color of a flesh tone.
13. The mask of claim 1, having facial expressions drawn, painted, or printed thereon.
14. The mask of claim 1, having attached to edges thereof a strap assembly which can pass around the wearer's head so as to hold the mask in place.
15. The mask of claim 14, wherein the strap assembly is attached with at least one adjustable interlocking component.
16. The mask of claim 14, wherein at least a portion of the strap assembly is elastic.
18. The mask of claim 17, wherein the multitude of layers of the metallic mesh in the heat exchanger is from about 8 to about 50 layers of metallic mesh, and the heat exchanger includes an outer layer with a cross-sectional area to the outer layer of the heat exchanger of no more than 24 square centimeters.
19. The mask of claim 18, wherein the mask has an effectiveness of warming outside air of at least 57 percent when the outside air temperature is 17.7 degrees Fahrenheit.
20. The mask of claim 19, wherein the effectiveness of warming the outside air is at least 70 percent when the outside air temperature is 33.4 degrees Fahrenheit..Iadd.
21. In a respiratory face mask including a facepiece and a metallic heat exchanger, said mask useful for warming and humidifying cold outside air wherein inhaled air comes directly into the mask from the outside air through the heat exchanger, and exhaled air goes from inside the mask through the heat exchanger directly to the outside air, the improvement which comprises an outer shell attached to the facepiece in a front part of the mask with the heat exchanger being a multi-layered metallic mesh heat exchanger enclosed inside the mask behind the outer shell, with an opening to the outside air provided below the multi-layered metallic mesh heat exchanger in the outer shell of the mask for inhalation and exhalation therethrough, wherein the opening and the multi-layered metallic mesh heat exchanger are located on the mask so as to be able to reduce a tendency of the heat exchanger to otherwise freeze in cold weather when the mask is worn when snow is falling or blowing..Iaddend..Iadd.22. A respiratory face mask which can be worn by a person, i.e., a wearer, who has a head, including a face, which mask comprises the following:
- an inner shell, with an edge thereof able to be placed in contact with the wearer's face to form an air seal when the mask is worn;
- a heat exchanger disposed in the mask, including a multitude of layers of metallic mesh, the layers being provided in a sheetlike arrangement, one layer upon another, and being such that air can flow back and forth across the layered arrangement in a direction from outside layer to inside layer and from inside layer to outside layer in a direction substantially perpendicular to the layers in the mask, and substantially perpendicular to the face of the wearer, during breathing by the wearer;
- an outer shell, generally spaced apart from the inner shell and the heat exchanger, which can deflect exhaled air downwardly to outside air through an opening when the mask is worn and the wearer's head is in an upright position;
- the opening being below the heat exchanger to allow entry of air inhaled by the wearer of the mask when the mask is worn and the wearer's head is in an upright position upwardly, and discharge of air exhaled by the wearer of the mask when the mask is worn and the wearer's head is in an upright position downwardly--such that exhaled air can heat the heat exchanger, which in turn can heat the inhaled air--with the outer shell, the opening and the heat exchanger being located on the mask so as to be able to reduce a tendency of the heat exchanger to otherwise freeze in cold weather when the mask is worn when snow is falling or blowing,
- wherein the mask is useful for warming and humidifying inhaled air efficiently,
- and wherein the inhaled air comes directly into the mask from the outside air through the heat exchanger, and the exhaled air goes from inside the mask through the heat exchanger directly to the outside air.
.Iaddend..Iadd.23. The mask of claim 22, wherein the multitude of layers of the metallic mesh in the heat exchanger are from about 8 to about 50 layers of metallic mesh..Iaddend..Iadd.24. The mask of claim 23, wherein the multitude of layers of the metallic mesh is of aluminum or brass..Iaddend.
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Type: Grant
Filed: Feb 14, 1997
Date of Patent: Mar 30, 1999
Inventor: R. Douglas Behr (Midland, MI)
Primary Examiner: Aaron J. Lewis
Assistant Examiner: V. Srivastava
Attorney: Christopher John Rudy
Application Number: 8/801,046
International Classification: A62B 714;
