Flavor-delivery article

• US 5,144,962 A
• Filed: 12/01/1989
• Issued: 09/08/1992
• Est. Priority Date: 12/01/1989
• Status: Expired due to Term

• Current Assignee: Philip Morris USA Incorporated (Altria Group, Inc.), Philip Morris Products SA (Philip Morris Limited)
• Original Assignee: Philip Morris USA Incorporated (Altria Group, Inc.)
• Inventors: Hajaligol, Mohammad R., Smith, Ulysses, Sprinkel, Francis M., Morgan, Constance H., Utsch, Francis V., Counts, Mary E.
• Primary Examiner(s): MILLIN, VINCENT A
• Application Number:
  US07/444,818
• Time in Patent Office: 1,012 Days
• Field of Search: 131/270, 131/194, 131/195, 131/329, 131/330, 131/335, 128/200.14, 128/202.21, 128/203.26, 128/203.27, 128/204.13
• US Class Current: 131/194
• CPC Class Codes: A24D 1/20 Cigarettes specially adapted for simulated smoking devices
• CPC Class Codes: A24F 40/20 Devices using solid inhalable precursors
• CPC Class Codes: A24F 40/46 Shape or structure of electric heating means
• CPC Class Codes: A24F 40/50 Control or monitoring
• CPC Class Codes: A24F 40/90 Arrangements or methods specially adapted for charging batteries thereof

Abstract

Methods and apparatus for releasing flavor components from a flavor-generating medium using an electric heating element are provided. A non-combustion flavor-generating article uses electrical energy to power a heating element which heats tobacco or other flavorants. The flavor-generating medium is formed into a packed bed. Energy delivered to the heating element is regulated to maintain the flavor-generating medium at a relatively constant operating temperature to ensure a relatively constant release of flavor.

Claims

1. Apparatus for deriving flavor from a flavor-generating medium comprising:

a positive temperature coefficient thermistor in thermal contact with said flavor-generating medium; and

means for selectively applying an electrical current to said thermistor to raise the temperature of the thermistor and thereby heat said flavor-generating medium and cause said flavor-generating medium to release flavor components.

2. The apparatus defined in claim 1 wherein said electrical current raises the temperature of said thermistor to its transition temperature.

3. The apparatus defined in claim 2 wherein the transition temperature of said thermistor is in the range from about 100°

C. to about 500°

C.

4. The apparatus defined in claim 3 wherein the transition temperature of said thermistor is in the range from about 120°

C. to about 400°

C.

5. The apparatus defined in claim 4 wherein the transition temperature of said thermistor is in the range from about 200°

C. to about 350°

C.

8. The apparatus defined in claim 1 further comprising means for filtering air and released flavor components.

9. The apparatus defined in claim 1 wherein said flavor-generating medium is a tobacco flavor source.

10. The apparatus defined in claim 1 wherein said means for selectively applying an electrical current is responsive to air passing over the flavor-generating medium.

13. The article defined in claim 1 further comprising means for filtering air drawn through said tube and passed over said flavor-generating medium.

14. The article defined in claim 1 wherein said thermistor has a transition temperature in the range from about 100°

C. to about 500°

C.

15. The article defined in claim 14 wherein said thermistor has a transition temperature in the range of about 120°

to about 400°

C.

16. The article defined in claim 15 wherein said thermistor has a transition temperature in the range of about 200°

C. to about 350°

C.

6. The apparatus defined in claim I further comprising means for pre-heating air to be drawn over the heated flavor-generating medium.

7. The apparatus defined in claim 6 wherein said means for pre-heating the air comprises a second positive temperature coefficient thermistor raised to its transition temperature.

11. A non-combustion smoking article comprising:

a hollow tube;

a flavor-generating medium disposed within said tube; and

a positive temperature coefficient thermistor disposed in said tube and adjacent to said flavor-generating medium for heating said flavor-generating medium and causing said flavor-generating medium to release tobacco flavor components.

12. The article defined in claim 11 wherein said tube is foil-lined.

17. The article defined in claim 11 further comprising means for thermally insulating at least a portion of said tube.

18. The article defined in claim 17 wherein said means for thermally insulating comprises:

an overwrap concentrically surrounding at least said portion of said tube; and

a layer of air disposed between said tube and said overwrap.

19. The article defined in claim 11, further comprising electrical contacts for connecting said thermistor to an external power source.

20. The article defined in claim 11 further comprising means for indicating that said flavor-generating medium has reached the end of its useful life.

21. The article defined in claim 11 further comprising a fusible link which melts to electrically disconnect said thermistor after a predetermined period of operation.

22. The article defined in claim 11, further comprising means for storing electrical energy, disposed within said smoking article and in electrical contact with said thermistor, for delivering electrical energy to said thermistor.

23. The article defined in claim 11 further comprising means for retaining said thermistor and said flavor-generating medium in said tube while allowing air to pass through said tube in contact with said flavor-generating medium.

24. Apparatus for deriving flavor from a flavor-generating medium comprising:

a first heating element in thermal contact with said flavor-generating medium for heating said flavor-generating medium;

a second heating element in thermal contact with said flavor-generating medium for heating said flavor-generating medium; and

means for applying electrical energy to said first and second heating elements and thereby heating said flavor-generating medium and causing said flavor-generating medium to release flavor components.

25. The apparatus of claim 24 further comprising means for regulating the amount of electrical energy applied to said first and second heating elements.

26. The apparatus of claim 24 wherein said first heating element raises the temperature of said flavor-generating medium to a first predetermined temperature, and second heating element raises the temperature of said flavor-generating medium to a second predetermined temperature.

27. The apparatus of claim 26 wherein said first predetermined temperature is above ambient temperature and below the temperature at which said flavor-generating medium generates flavor components.

28. The apparatus of claim 26 wherein said second predetermined temperature is above the temperature at which said flavor-generating medium generates flavor components and below the combustion temperature of said flavor-generating medium.

29. The apparatus of claim 26 wherein said electrical energy is applied to said first heating element substantially continuously, and said electrical energy is selectively applied to said second heating element.

30. The apparatus of claim 24 further comprising means disposed within said article for storing said electrical energy before said energy is applied to said first and second heating elements.

31. The apparatus of claim 30 wherein said means for storing electrical energy comprises a battery.

32. The apparatus of claim 30 wherein said means for storing electrical energy comprises a capacitor.

33. The apparatus of claim 24 further comprising means for filtering air and released flavor components.

34. The apparatus of claim 24 wherein said flavor-generating medium comprises a tobacco flavor source.

53. The apparatus of claim 34 wherein said means for applying a predetermined temperature controlling cycle comprises:

means for maintaining said flavor-generating medium at a first predetermined temperature during a first predetermined time interval; and

means for maintaining said flavor-generating medium at a second predetermined temperature for at least a second predetermined time interval.

54. The apparatus of claim 53 wherein said means for maintaining a first predetermined temperature comprises means for maintaining a temperature above the temperature at which flavor components are generated and below the combustion temperature of said flavor-generating medium.

55. The apparatus of claim 53 wherein said means for maintaining a second predetermined temperature comprises means for maintaining a temperature above ambient temperature and below the temperature at which said flavor-generating medium generates flavor components.

35. Apparatus for deriving flavor from a flavor-generating medium comprising:

a heating element in thermal contact with said flavor-generating medium; and

means for applying electrical energy to said heating element and thereby heating said flavor-generating medium and causing said flavor-generating medium to release flavor components;

means for regulating the amount of electrical energy delivered to said heating element while said electrical energy is being applied to said heating element, said means for regulating comprising means for controlling the temperature of said flavor-generating medium, including means for applying a predetermined temperature controlling cycle to said flavor-generating medium.

36. The apparatus of claim 35 further comprising means disposed within said apparatus for storing said electrical energy before said energy is applied to said heating element.

37. The apparatus defined in claim 36 further comprising a hollow tube;

wherein;

said tube provides a housing for said apparatus;

said tube is separable along its length into a first and a second portion; and

said first and second portions include said flavor-generating medium and said means for storing electrical energy, respectively.

38. The apparatus defined in claim 37 wherein said first portion of said tube is openable to permit said flavor-generating medium to be replaced.

39. The apparatus of claim 36 further comprising a capacitor disposed within said apparatus, wherein said means for storing simultaneously charges said capacitor and delivers electrical energy to said heating element to raise the temperature of said heating element to a first predetermined temperature.

40. The apparatus of claim 39 wherein said means for storing comprises a battery.

41. The apparatus of claim 39 wherein said capacitor is selectively discharged to deliver electrical energy to said heating element to raise the temperature of said heating element to a second predetermined temperature.

42. The apparatus of claim 41 further comprising means responsive to air passing over the flavor-generating medium for discharging said capacitor.

43. The apparatus of claim 35 wherein said means for storing electrical energy comprises a battery.

44. The apparatus defined in claim 43 wherein said battery is capable of supplying between about 20 and about 500 milliwatt-hours of energy.

45. The apparatus of claim 35 wherein said means for storing electrical energy comprises a capacitor.

46. The apparatus of claim 36 wherein said means for storing is capable of slowly charging with said electrical energy and then quickly discharging said energy to said heating element.

47. The apparatus of claim 46 wherein said means for storing includes a battery which slowly charges a capacitor, and said capacitor quickly discharges to said heating element.

48. The apparatus of claim 35 wherein said heating element raises the temperature of said flavor-generating medium to a temperature of about 100°

C. to about 500°

C.

49. The apparatus of claim 48 wherein said heating element raises the temperature of said flavor-generating medium to a temperature of about 120°

C. to about 400°

C.

50. The apparatus of claim 49 wherein said heating element raises the temperature of said flavor-generating medium to a temperature of about 200°

C. to about 350°

C.

51. The apparatus of claim 35 further comprising means for filtering air and released flavor components.

52. The apparatus of claim 35 wherein said flavor-generating medium comprises a tobacco flavor source.

56. The apparatus of claim 35 further comprising means responsive to air passing over the flavor-generating medium for initiating the application of electrical energy to said heating element.

57. Apparatus for deriving flavor from a flavor-generating medium comprising:

a heating element in thermal contact with said flavor-generating medium for heating said flavor-generating medium to release flavor components; and

means for storing electrical energy and applying said energy to said heating element such that more energy is applied to said heating element when said heating element has a relatively low temperature, and less energy is applied to said heating element when said heating element has a relatively high temperature, thereby heating said flavor-generating medium and maintaining said flavor-generating medium at a relatively consistent temperature to release flavor components substantially consistently.

58. The apparatus of claim 57 wherein said heating element raises the temperature of said flavor-generating medium to a temperature of about 100°

C. to about 500°

C.

59. The apparatus of claim 58 wherein said heating element raises the temperature of said flavor-generating medium to a temperature of about 125°

C. to about 400°

C.

60. The apparatus of claim 59 wherein said heating element raises the temperature of said flavor-generating medium to a temperature of about 200°

C. to about 350°

C.

61. The apparatus of claim 57 wherein said flavor-generating medium comprises is a tobacco flavor source.

62. The apparatus of claim 57 further comprising means for filtering air and released flavor components.

63. The apparatus of claim 57 wherein said means for storing electrical energy comprises a battery.

64. The apparatus of claim 63 wherein said battery is rechargeable.

65. The apparatus defined in claim 63 wherein said battery is capable of supplying between about 20 to about 500 milliwatt-hours of energy.

66. The apparatus of claim 57 wherein said means for storing electrical energy comprises a capacitor.

67. The apparatus defined in claim 57 further comprising a hollow tube;

wherein;

said tube provides a housing for said apparatus;

said tube is separable along its length into a first and a second portion; and

said first and second portions include said flavor-generating medium and said means for storing electrical energy, respectively.

68. The apparatus defined in claim 67 wherein said first portion of said tube is openable to permit said flavor-generating medium to be replaced.

69. Apparatus for supplying electrical energy to electrical contacts of an electrically-powered flavor-generating article having an internal means for storing electrical energy, comprising:

means for storing electrical energy;

means for containing said means for storing electrical energy; and

means for making electrical contact between said means for storing and electrical energy and said electrical contacts of said article, to charge said internal means for storing energy of said flavor-generating article.

70. The apparatus defined in claim 69 further comprising means for controlling the amount of electrical energy delivered to said article.

71. The apparatus defined in claim 70 wherein said means for controlling prevents overcharging of a battery within said article by converting excess electrical energy to heat when said battery has been charged to a predetermined level.

72. The apparatus defined in claim 70 wherein said means for controlling prevents overcharging of a battery within said article by opening the electrical circuit between said means for storing electrical energy and said battery when said battery has been charged to a predetermined level.

73. The apparatus defined in claim 69 further comprising means for selectively applying power to said article.

74. The apparatus defined in claim 69 wherein said means for storing electrical energy receives power from a nominal 120 volt power source via a transformer.

84. The article of claim 74 further comprising means for indicating that said relatively high voltage is being applied to said heating element.

85. The apparatus of claim 70 wherein said switching means is responsive to air passing over the flavor-generating medium.

75. An electrically-heated flavor-generating article for deriving flavor from a flavor-generating medium comprising:

a heating element in thermal contact with said flavor-generating medium for heating said flavor-generating medium to release flavor components;

a battery for delivering electrical energy to said heating element; and

control means comprising an electronic circuit electrically connected to said battery and said heating element for controlling the temperature of said heating element, including means for applying a predetermined voltage cycle to said heating element, said electronic circuit comprising;

switching means for initiating said predetermined voltage cycle,

meansf or applying a relatively high voltage to said heating element during a first predetermined time interval, and

means for preventing said means for applying a relatively high voltage from operating during a second predetermined time interval.

76. The article of claim 75 further comprising means for filtering air and released flavor components.

77. The article of claim 75 wherein application of said relatively high voltage to said heating element heats said flavor-generating medium to a temperature in the range between the temperature at which flavor components are produced and the combustion temperature of said flavor-generating medium.

78. The article of claim 75 wherein said first predetermined time interval is between about 0.2 seconds to about 4.0 seconds.

79. The article of claim 75 wherein said second predetermined time interval is between about seconds to about 30 seconds.

80. The article of claim 75 wherein said electronic circuit further comprises means for applying a relatively low voltage to said heating element whenever said means for applying a relatively high voltage is not operating.

81. The article of claim 80 wherein application of said relatively low voltage heats said flavor-generating medium to a temperature above ambient temperature but below the temperature at which said flavor-generating medium generates flavor components.

82. The article of claim 81 further comprising means for indicating that said relatively low voltage is being applied to said heating element.

83. The article of claim 75 wherein said flavor-generating means is a tobacco flavor source.

86. In combination:

(1) A smoking article comprising;

(a) a hollow tube,

(b) a flavor-generating medium which releases tobacco flavor components when heated to a predetermined temperature, and

(c) means for capturing said flavor-generating medium while allowing air to pass in contact therewith, said means for capturing being thermally conductive and connected to said tube such that at least a portion thereof is exposed; and

(2) Apparatus for heating said flavor-generating medium of said smoking article comprising;

(a) a housing having a recess for receiving said portion of said smoking article which captures said flavor-generating medium,

(b) a heating element disposed adjacent said recess such that said heating element is in thermal contact with said flavor-generating medium when said portion is received in said recess, and

(c) means for selectively applying electrical power to said heating element to raise the temperature of said heating element and thereby heat said flavor-generating medium and cause said flavor-generating medium to release tobacco flavor components.

87. The apparatus of claim 86 wherein said apparatus for heating said flavor-generating medium further comprises means for passing air over the heated flavor-generating medium to mix said air with released tobacco flavor components and to convey the released tobacco flavor components away from said flavor-generating medium with said air.

88. The apparatus of claim 86 wherein said heating element is a positive temperature coefficient thermistor.

89. The apparatus of claim 88 wherein said thermistor is a hollow, open-ended cylinder surrounding at least a portion of said recess.

90. The apparatus of claim 86 wherein said apparatus for heating said flavor-generating medium further comprises means for pre-heating air to be passed over the heated flavor-generating medium.

91. The apparatus of claim 86 wherein said means for selectively applying electrical power is a pressure-activated switch which applies electrical power to said heating element when said smoking article has been properly positioned inside said recess.

92. The method of deriving flavor from a flavor-generating medium comprising the steps of:

positioning a positive temperature coefficient thermistor adjacent said flavor-generating medium; and

applying electrical current to said thermistor to raise the temperature of said thermistor and thereby heat said flavor-generating medium and cause said flavor-generating medium to release flavor components.

93. The method defined in claim 92 further comprising the step of passing air over the heated flavor-generating medium to mix said air with released flavor components and to convey the released flavor components away from said flavor-generating medium with said air.

94. The method defined in claim 93 further comprising the steps of:

positioning a heating element in the path of the air to be passed over said flavor-generating medium; and

applying electrical current to said heating element to raise the temperature of said heating element and thereby pre-heat air to be passed over said flavor-generating medium.

95. The method defined in claim 93 further comprising the step of filtering the mixture of air and released flavor components.

96. The method defined in claim 92 wherein said electrical current raises the temperature of said thermistor to its transition temperature.

97. The method defined in claim 96 wherein the transition temperature of said thermistor is in the range from about 100°

C. to about 500°

C.

98. A method for deriving flavor from a flavor-generating medium comprising the steps of:

positioning a heating element adjacent said flavor-generating medium; and

applying electrical current to said heating element to raise the temperature of said heating element according to a predetermined temperature cycle and thereby controlling the temperature of said flavor-generating medium and the amount of flavor components released therefrom, said step of applying electrical current comprising regulating the amount of electrical current delivered to said heating element while said electrical current is being applied to said heating element, said regulating step comprising controlling the temperature of said flavor-generating medium by applying a predetermined temperature controlling current cycle to said flavor-generating medium.

99. The method defined in claim 98 wherein said flavor-generating medium comprises a tobacco flavor source.

100. The method defined in claim 98 further comprising the step of passing air over the heated flavor-generating medium to mix said air with the released flavor and to convey the released flavor components away from said flavor-generating medium with said air.

101. The method of claim 100 further comprising the step of filtering said mixture of air and released flavor components.

102. The method of claim 100 further comprising the steps of:

positioning a second heating element in thermal contact with said air; and

applying electrical energy to said second heating element for pre-heating said air before passing said air over the heated flavor-generating medium.

103. The method of claim 98 wherein said step of applying a predetermined temperature controlling current cycle comprises the steps of:

applying electrical current to said heating element to raise the temperature of said heating element during a first time interval to a first predetermined temperature that is below the temperature required to release flavor components from said flavor-generating medium; and

applying electrical current to raise the temperature of said heating element to a second predetermined temperature during a second predetermined time interval to release flavor components.

104. The method of claim 103 wherein said first predetermined temperature is a temperature above ambient temperature and below the temperature required to release flavor components from said flavor-generating medium.

105. The method of claim 103 wherein said second predetermined temperature is a temperature above the temperature required to release flavor components and below the combustion temperature of said flavor-generating medium.

106. A method for deriving flavor components from a flavor-generating medium, comprising:

positioning a heating element in thermal contact with said flavor-generating medium; and

applying electrical energy to said heating element according to a predetermined voltage cycle to raise the temperature of said heating element and thereby heat said flavor-generating medium and cause said flavor-generating medium to release flavor components, said step of applying electrical energy comprising the steps of;

applying a first predetermined voltage to said heating element for a first time interval to heat said flavor-generating medium to a temperature above ambient temperature but below the temperature at which said flavor-generating medium produces flavor components; and

applying a second predetermined voltage to said heating element for a second predetermined time interval to heat said flavor-generating medium to a temperature above the temperature at which said flavor-generating medium produces flavor components but below the combustion temperature.

107. The method defined in claim 106 further comprising the step of passing air over the heated flavor-generating medium to mix said air with the released flavor components and to convey the released flavor components away from said flavor-generating medium with said air.

108. The method defined in claim 107 further comprising the step of filtering said mixture of air and released flavor components.

109. The method of claim 106 wherein said step of applying electrical energy comprises the steps of:

charging an energy storage device with electrical energy at a first predetermined rate; and

discharging said energy from said energy storage device to said heating element at a second predetermined rate to heat said heating element.

110. Apparatus for deriving flavor from a flavor-generating medium comprising:

a heating element in thermal contact with said flavor-generating medium for heating said medium to release flavor components;

means for sensing the temperature of said flavor-generating medium; and

means responsive to said means for sensing for controlling power to said heating element and thereby controlling the heating of said flavor-generating medium.

111. The apparatus of claim 110 wherein said means for sensing is a thermocouple.

112. The apparatus of claim 110 wherein said means for sensing is a thermistor.

113. Apparatus for deriving flavor from a flavor-generating medium comprising:

a heating element, said heating element having an external surface in thermal contact with an external surface of said flavor-generating medium; and

means for applying electrical energy to said heating element and thereby heating said flavor-generating medium and causing said flavor-generating medium to release flavor components; and

means for regulating the amount of electrical energy delivered to said heating element while said electrical energy is being applied to said heating element.

114. The apparatus of claim 113 wherein said flavor-generating medium comprises a packed bed of pellets containing flavor components.

115. The apparatus of claim 113 wherein said flavor-generating medium comprises an extruded rod containing flavor components.

116. The apparatus of claim 113 wherein said flavor-generating medium surrounds an external surface of said heating element.

117. The apparatus of claim 113 wherein said heating element surrounds an external surface of said flavor-generating medium.

118. The apparatus of claim 113 further comprising means disposed within said apparatus for storing said electrical energy before said energy is applied to said heating element.

119. The apparatus defined in claim 118 further comprising a hollow tube;

wherein;

said tube provides a housing for said apparatus;

said tube is separable along its length into a first and a second portion; and

said first and second portions include said flavor-generating medium and said means for storing electrical energy, respectively.

120. The apparatus defined in claim 119 wherein said first portion of said tube is openable to permit said flavor-generating medium to be replaced.

121. The apparatus of claim 118 wherein said means for storing electrical energy comprises a battery.

122. The apparatus defined in claim 121 wherein said battery is capable of supplying between about 20 and about 500 milliwatt-hours of energy.

123. The apparatus of claim 118 wherein said means for storing electrical energy comprises a capacitor.

124. The apparatus of claim 118 wherein said means for storing is capable of slowly charging with said electrical energy and then quickly discharging said energy to said heating element.

125. The apparatus of claim 124 wherein said means for storing includes a battery which slowly charges a capacitor, and said capacitor quickly discharges to said heating element.

126. The apparatus of claim 113 wherein said heating element raises the temperature of said flavor-generating medium to a temperature of about 100°

C. to about 500°

C.

127. The apparatus of claim 126 wherein said heating element raises the temperature of said flavor-generating medium to a temperature of about 120°

C. to about 400°

C.

128. The apparatus of claim 127 wherein said heating element raises the temperature of said flavor-generating medium to a temperature of about 200°

C. to about 350°

C.

129. The apparatus of claim 113 further comprising means for filtering air and released flavor components.

130. The apparatus of claim 113 wherein said flavor-generating medium comprises a tobacco flavor source.

131. The apparatus of claim 113 wherein said means for regulating comprises means for controlling the temperature of said flavor-generating medium, including means for applying a predetermined temperature controlling cycle to said flavor-generating medium.

132. The apparatus of claim 131 wherein said means for applying a predetermined temperature controlling cycle comprises:

means for maintaining said flavor-generating medium at a first predetermined temperature during a first predetermined time interval; and

means for maintaining said flavor-generating medium at a second predetermined temperature for at least a second predetermined time interval.

133. The apparatus of claim 132 wherein said means for maintaining a first predetermined temperature comprises means for maintaining a temperature above the temperature at which flavor components are generated and below the combustion temperature of said flavor-generating medium.

134. The apparatus of claim 132 wherein said means for maintaining a second predetermined temperature comprises means for maintaining a temperature above ambient temperature and below the temperature at which said flavor-generating medium generates flavor components.

135. A method for deriving flavor from a flavor-generating medium comprising the steps of:

positioning an external surface of a heating element adjacent an external surface of said flavor-generating medium; and

applying electrical current to said heating element to raise the temperature of said heating element according to a predetermined temperature cycle and thereby controlling the temperature of said flavor-generating medium and the amount of flavor components released therefrom.

136. The method of claim 135 wherein said flavor-generating medium comprises a packed bed of pellets containing flavor components.

137. The method of claim 135 wherein said flavor-generating medium comprises an extruded rod containing flavor components.

138. The method of claim 135 wherein said flavor-generating medium is positioned around an external surface of said heating element.

139. The method of claim 135 wherein said heating element is positioned around an external surface of said flavor-generating medium.

140. The method defined in claim 135 wherein said flavor-generating medium comprises a tobacco flavor source.

141. The method defined in claim 135 further comprising the step of passing air over the heated flavor-generating medium to mix said air with the released flavor and to convey the released flavor components away from said flavor-generating medium with said air.

142. The method of claim 141 further comprising the step of filtering said mixture of air and released flavor components.

143. The method of claim 141 further comprising the steps of:

positioning a second heating element in thermal contact with said air; and

applying electrical energy to said second heating element for pre-heating said air before passing said air over the heated flavor-generating medium.

144. The method of claim 135 wherein said step of applying electrical current comprises the steps of:

applying electrical current to said heating element to raise the temperature of said heating element during a first time interval to a first predetermined temperature that is below the temperature required to release flavor components from said flavor-generating medium; and

applying electrical current to raise the temperature of said heating element to a second predetermined temperature during a second predetermined time interval to release flavor components.

145. The method of claim 144 wherein said first predetermined temperature is a temperature above ambient temperature and below the temperature required to release flavor components from said flavor-generating medium.

146. The method of claim 144 wherein said second predetermined temperature is a temperature above the temperature required to release flavor components and below the combustion temperature of said flavor-generating medium.