US3902045A - Electric convection heater having a friction-type blower - Google Patents

Electric convection heater having a friction-type blower Download PDF

Info

Publication number
US3902045A
US3902045A US334446A US33444673A US3902045A US 3902045 A US3902045 A US 3902045A US 334446 A US334446 A US 334446A US 33444673 A US33444673 A US 33444673A US 3902045 A US3902045 A US 3902045A
Authority
US
United States
Prior art keywords
rotor
heating element
fins
air
heater according
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US334446A
Other languages
English (en)
Inventor
Ingeborg Laing
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Application granted granted Critical
Publication of US3902045A publication Critical patent/US3902045A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
    • F24H3/00—Air heaters
    • F24H3/02—Air heaters with forced circulation
    • F24H3/04—Air heaters with forced circulation the air being in direct contact with the heating medium, e.g. electric heating element
    • F24H3/0405—Air heaters with forced circulation the air being in direct contact with the heating medium, e.g. electric heating element using electric energy supply, e.g. the heating medium being a resistive element; Heating by direct contact, i.e. with resistive elements, electrodes and fins being bonded together without additional element in-between
    • F24H3/0411—Air heaters with forced circulation the air being in direct contact with the heating medium, e.g. electric heating element using electric energy supply, e.g. the heating medium being a resistive element; Heating by direct contact, i.e. with resistive elements, electrodes and fins being bonded together without additional element in-between for domestic or space-heating systems
    • F24H3/0417—Air heaters with forced circulation the air being in direct contact with the heating medium, e.g. electric heating element using electric energy supply, e.g. the heating medium being a resistive element; Heating by direct contact, i.e. with resistive elements, electrodes and fins being bonded together without additional element in-between for domestic or space-heating systems portable or mobile

Definitions

  • An electrical resistance convection heater has a friction-type blower rotor comprising a plurality of spaced annular fins in the form of a helix of substantially flat laminar material. The pitch of the helix is so small that each turn of the helix approaches a laminar annulus.
  • the interior of the rotor forms an axial interior air inlet whereby when the rotor is rotated by an electric motor, air enters the interior of the rotor in an axial direction and flows through the exterior of the rotor in a radial direction through the spaces between the axially spaced rotor fins.
  • a stationary annular electric heating element is mounted coaxially with respect to the rotor and located upstream thereof in the direction of air flow through the rotor for heating the air flow.
  • the heating element may comprise a laminar metal strip in helix form, the turns of which constitute a plurality of axially spaced annular fins. In one embodiment such a heating element is arranged so that the tins of the heating element are substantially copla nar with respect to the rotor fins.
  • the heating element may be a strip corrigated in zig-zig fashion.
  • PATENTED 3 902 045 sum 3 of 3 ELECTRIC CONVECTION HEATER HAVING A FRICTION-TYPE BLOWER THE PRIOR ART
  • Portable fan heaters have found a wide application in the household, particularly for transition heating.
  • a drawback of known appliances is that they generate an objectionable air noise.
  • the fan system may be a noise source, and also so may the heating element.
  • An aim of the invention is a low-noise fan heater which is effective and efficient. Further the rotary parts are such that the requirement of physical protection is reduced.
  • the invention resides in that the rotor is a friction blower rotor, with annular axially-spaced fins constituting a cylindrical figure of revolution and that a resistance heating element is arranged coaxial with and upstream of the rotor so that the air traverses this heating element before it is engaged by the annular discs. It has already been proposed to arrange the heating elements on the upstream side of a bladed centrifugal blower. This arrangement has the disadvantage that the blower must pass a greater volume and this results in lower pressure and delivery coefficients as well as lower efficiencies.
  • the acceleration of the air is accomplished by virtually flat elements of continuous profile which frictionally, use the viscosity of the air to accelerate it tangentially.
  • the friction between the elements and the air in the boundary layers is the operative energy-conversion force.
  • This friction is a function of the air viscosity.
  • the air viscosity increases substantially with the increase of temperature.
  • Providing the fan downstream of the heating element uses the increased viscosity of and raised temperature of the air to advantage by providing an effective low-noise heating appliance. This is in contrast to known appliances in which the temperature effects lead to disadvantages.
  • FIG. 1 shows diagrammatically, in cross-section along the axis, a heating appliance according to the invention.
  • FIGS. 2A and 2B show, in two cross-sections at right angles to each other, another embodiment of a heating appliance according to the invention.
  • FIG. 3 shows, in a cross-section similar to that of FIG. 1, a third embodiment of the heating appliance according to the invention.
  • FIG. 4 shows, in a diagrammatic cross-section, the possible correlation of a blower according to the invention with the blower casing parts which guide the air stream.
  • the motor 1 drives the hollow cylindrical rotor 3 via the wheel disc 2.
  • the rotor 3 consists of a large number of virtually flat annular fins 4 which are preferably manufactured by helically coiling an aluminium strip. Although speaking exactly, there is only one fin comprised by a continuous helix of strip metal, for practical purposes it can be considered as a plurality of annuli and is described as such; indeed it may be desirable in some cases to manufacture the rotor by assembling a plurality of individual laminar annuli.
  • the fins 4 are held axially spaced by bolts 5 which are placed as nearly as possible at minimum radius of the fin assembly, spaced by distance pieces (not shown).
  • the distance can be ensured, for example, by washers or flanges around the bolt-holes in the fins 4. Room air is sucked in from below along the arrow 7, all around the appliance.
  • the casing consists of the discs ll, 18 and 19 held assembled by bolts 24.
  • the resistance heating element 8 is also formed as a helical strip of suitable metal having a large ratio of width to thickness.
  • the distance spacing of the helical turns is here maintained by insulating posts 9.
  • the heated air proceeds as indicated by the arrow 10 into the inside of the rotor 3, and is thus engaged by the fins 4 by way of friction forces in a manner already described.
  • the heated air is discharged with a radial velocity component indicated by the arrow 22.
  • Slots 12 are provided to give access for cooling air for the motor 1.
  • a cylindrical separating wall 13 is provided in the casing 19 protectively surrounding the motor 1. Air is sucked through the apertures 12 as indicated by the arrow 14. It then cools the motor 1 and emerges through a frustoconical slot 15 to be entrained and accelerated outwards as indicated by arrow 17.
  • FIG. 2A shows another embodiment of the fan heater according to FIG. 1 in which the heating element 20 is formed of strip corrugated in zigzag formation.
  • the major area of the heat dissipating regions lies radially.
  • the fins 4' are so formed that their surfaces lie on frustoconical nested surfaces concentric with the rotor axis.
  • FIG. 2B shows a cross-section along the section line IIb-Ilb of FIG. 2A from which the radial arrangement of the resistance heater 20 can be seen.
  • the air is sucked in radially from the outside as indicated by the arrows 28.
  • the motor 21 is attached to the coverplate 23 which is mounted on the baseplate 25, as in FIG. 1, by bolts or studs 24 which may be so numerous as virtually to form a protective cage.
  • FIG. 3 shows diagrammatically an embodiment ac cording to FIG. 1 in which, however, the heating element 8 comprising a helical strip, on its posts 9 is located inside the rotor 3' and is substantially coplanar with the rotor which comprises a helical strip 4.
  • the cylindrical wall 13 ceases to be necessary.
  • the motor 1 is attached to the annular floor portion 31 by spoke-like arms 30.
  • feet 32 extending downward from the portion 31, the annular portion affords passage for the entry of air to the inside space 33. Air flows axially into the rotor along the path indicated by arrow 34, through inlet openings between the arms 30 and then radially out of the rotor between the axially spaced fins 4 along the path indicated by arrow 35.
  • FIG. 4 shows diagrammatically in cross-section an appliance according to the invention in which the rotor 40 is arranged in a volute casing so that the emerging air stream is directed as indicated by the arrows 42 and 46.
  • This formation may be applied with simple design modification, to the earlier described embodiments.
  • An electrical resistance convection heater having a friction-type blower rotor comprising a plurality of axially spaced annular fins in the form of a helix of substantially flat laminar material where the pitch of the helix is so small that each turn of the helix approaches a laminar annulus and where the annular interior forms an axial interior air inlet whereby when said rotor is rotated air enters the interior of the rotor in an axial direction and flows to the exterior of the rotor in a radial direction through the spaces between the axially spaced fins, a motor for rotating the rotor, and a stationary annular heating element mounted coaxially with respect to the rotor and located upstream of the rotor with respect to the direction of air flow through the rotor.
  • Heating appliance according to claim 1 characterised in that the rotor fins are virtually frustoconical surfaces nested concentrically with the rotor axis.
  • a heater according to claim 1 in which the motor is exposed to a flow of cooling air for which passages are provided separately from the flow of air heated by the appliance.
  • a heater according to claim 5 in which blower means are provided for the flow of cooling air which flow of cooling air is independent from the flow of air caused by the said rotor.
  • heating element comprises a laminar metal strip in helix form with axially spaced turns wherein substantially plane surfaces of the strip extend radially of the axis of the rotor.
  • An electrical resistance convection heater according to claim 7 having an axially extending insulative post supporting the metal strip.
  • An electrical resistance convection heater according to claim 1 having a spoke-like structure mounting said motor on one side thereof and legs on the other side of said spoke-like structure opposite said motor whereby air flowing into said rotor passes around said legs and through the spoke-like structure.
  • An electrical resistance convection heater having in addition a casing structure comprising disc-like parts located axially exterior of said rotor and heating element with said disc-like parts interconnected coaxially in parallel planes and having axially extending bolts connecting said disc-like parts near their outer peripheries to form a cage protecting said rotor and said heating element and where one said disc-like part has an opening therein through which air may enter the interior of said rotor in an axial direction.
  • An electrical resistance convection heater having a friction-type blower rotor comprising a plurality of axially spaced annular fins the annular interior of which forms an axial interior air inlet whereby when said rotor is rotated air enters the interior of the rotor in an axial direction and flows to the exterior of the rotor in a radial direction through the spaces between the axially spaced fins, a motor for rotating the rotor, and a stationary annular heating element mounted concentrically and substantially coextensively with respect to the rotor and located upstream of the rotor with respect to the direction of air flow through the rotor, said annular heating element constituting a plurality of axially spaced annular metallic fins, said heating element fins being substantially coplanar with respect to said rotor fins.
  • a heater according to claim 13 in which a volute casing surrounds at least the rotor so as to deliver the heated air therefrom in a directed stream subtending substantially less then 360 referred to the axis.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Direct Air Heating By Heater Or Combustion Gas (AREA)
US334446A 1972-03-02 1973-02-21 Electric convection heater having a friction-type blower Expired - Lifetime US3902045A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
AT172472A AT320807B (de) 1972-03-02 1972-03-02 Elektrisches Heizgerät mit elektromotorisch betriebenem Lüfter

Publications (1)

Publication Number Publication Date
US3902045A true US3902045A (en) 1975-08-26

Family

ID=3519634

Family Applications (1)

Application Number Title Priority Date Filing Date
US334446A Expired - Lifetime US3902045A (en) 1972-03-02 1973-02-21 Electric convection heater having a friction-type blower

Country Status (8)

Country Link
US (1) US3902045A (de)
JP (1) JPS5810660B2 (de)
AT (1) AT320807B (de)
DD (1) DD102461A5 (de)
DE (1) DE2308355C3 (de)
FR (1) FR2174302B1 (de)
GB (1) GB1421588A (de)
SE (1) SE414665B (de)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4402647A (en) * 1979-12-06 1983-09-06 Effenberger Udo E Viscosity impeller
US4972570A (en) * 1989-04-11 1990-11-27 Tateishi Art K Method of manufacturing an oscillating fan
US6553923B2 (en) * 2000-08-30 2003-04-29 William Stuart Gatley, Jr. Blower housing with maximized interior spacing
US20100111720A1 (en) * 2008-11-06 2010-05-06 Nicholas Andrew Hiner High displacement air pump

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3120198A1 (de) * 1981-05-21 1982-12-09 Braun Ag, 6000 Frankfurt Transportables lueftergeraet mit elektromotorisch betriebenem geblaese
JPS6016884U (ja) * 1983-07-13 1985-02-05 株式会社クボタ 板状潜熱蓄熱カプセル
CA1209631A (en) * 1983-08-12 1986-08-12 David M. Howie Combined radiant and fan heater
JPS60122894A (ja) * 1983-12-05 1985-07-01 Matsushita Electric Ind Co Ltd 蓄熱槽
JPS6123079U (ja) * 1984-07-11 1986-02-10 株式会社クボタ 平板状潜熱蓄熱カプセル
JPH0220632Y2 (de) * 1984-11-09 1990-06-05
JPS6189675U (de) * 1984-11-09 1986-06-11
GB8431450D0 (en) * 1984-12-13 1985-01-23 Victor Mfg Ltd Heating unit
JPH0197149U (de) * 1987-12-21 1989-06-28
DE102004033374A1 (de) * 2004-07-09 2006-02-16 BSH Bosch und Siemens Hausgeräte GmbH Gargeräteheizvorrichtung mit einem Lüfterrad und mit einem Heizelement
DE102019126146A1 (de) 2019-09-27 2021-04-01 Hochschule für Technik und Wirtschaft Dresden Belüftungsvorrichtung für Wände und/oder Ecken in Innenbereichen

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US886682A (en) * 1906-08-23 1908-05-05 Electric Controller & Supply Company Electric heater and rheostat.
US1061142A (en) * 1909-10-21 1913-05-06 Nikola Tesla Fluid propulsion
US1455022A (en) * 1923-05-15 Turbine
US1828809A (en) * 1929-07-19 1931-10-27 Hugh G Landis Electric heater
US1903219A (en) * 1928-08-17 1933-03-28 Hugh G Landis Electric heater
US1977357A (en) * 1931-02-09 1934-10-16 Alonzo W Slayback Inducting and discharging device for fluids
US2321907A (en) * 1941-05-31 1943-06-15 Bell Telephone Labor Inc Blower device
US2632598A (en) * 1950-04-05 1953-03-24 Theodore Backer Centrifugal blower
US2702332A (en) * 1952-02-27 1955-02-15 Bois Robert E Du Electric resistor
US2710907A (en) * 1953-01-02 1955-06-14 Sun Electric Corp Energy transfer unit
US3218437A (en) * 1965-11-16 Ng electrical heater elements
US3303325A (en) * 1964-02-17 1967-02-07 Gen Electric Electric hair dryer having combined motor switch and thermostatic heater switch control means

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR659029A (fr) * 1928-08-14 1929-06-24 Perfectionnements aux appareils de chauffage électriques
DE599519C (de) * 1932-10-16 1934-07-04 Carl Heinrich Dencker Dr Ing Zentrifugal-Reibungsgeblaese, dessen Laeufer aus nebeneinanderliegenden Scheiben besteht
US3211891A (en) * 1963-07-05 1965-10-12 Mach & Electric Thermal fan
GB1034529A (en) * 1963-11-25 1966-06-29 Shearman & Kingscote Ltd Improvements relating to electric space heaters

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1455022A (en) * 1923-05-15 Turbine
US3218437A (en) * 1965-11-16 Ng electrical heater elements
US886682A (en) * 1906-08-23 1908-05-05 Electric Controller & Supply Company Electric heater and rheostat.
US1061142A (en) * 1909-10-21 1913-05-06 Nikola Tesla Fluid propulsion
US1903219A (en) * 1928-08-17 1933-03-28 Hugh G Landis Electric heater
US1828809A (en) * 1929-07-19 1931-10-27 Hugh G Landis Electric heater
US1977357A (en) * 1931-02-09 1934-10-16 Alonzo W Slayback Inducting and discharging device for fluids
US2321907A (en) * 1941-05-31 1943-06-15 Bell Telephone Labor Inc Blower device
US2632598A (en) * 1950-04-05 1953-03-24 Theodore Backer Centrifugal blower
US2702332A (en) * 1952-02-27 1955-02-15 Bois Robert E Du Electric resistor
US2710907A (en) * 1953-01-02 1955-06-14 Sun Electric Corp Energy transfer unit
US3303325A (en) * 1964-02-17 1967-02-07 Gen Electric Electric hair dryer having combined motor switch and thermostatic heater switch control means

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4402647A (en) * 1979-12-06 1983-09-06 Effenberger Udo E Viscosity impeller
US4972570A (en) * 1989-04-11 1990-11-27 Tateishi Art K Method of manufacturing an oscillating fan
US6553923B2 (en) * 2000-08-30 2003-04-29 William Stuart Gatley, Jr. Blower housing with maximized interior spacing
USRE40818E1 (en) 2000-08-30 2009-07-07 Gatley Jr William Stuart Blower housing with maximized interior spacing
US20100111720A1 (en) * 2008-11-06 2010-05-06 Nicholas Andrew Hiner High displacement air pump

Also Published As

Publication number Publication date
FR2174302B1 (de) 1976-04-30
GB1421588A (en) 1976-01-21
SE414665B (sv) 1980-08-11
JPS48100737A (de) 1973-12-19
AT320807B (de) 1975-02-25
JPS5810660B2 (ja) 1983-02-26
DE2308355A1 (de) 1973-09-06
DE2308355C3 (de) 1980-01-10
DE2308355B2 (de) 1976-03-18
FR2174302A1 (de) 1973-10-12
DD102461A5 (de) 1973-12-12

Similar Documents

Publication Publication Date Title
US3902045A (en) Electric convection heater having a friction-type blower
US4696283A (en) Kinetic heater
US5841943A (en) Ducted flow hair dryer with multiple impellers
EP0183252A2 (de) Elektrischer Lufterhitzer
CN105402143B (zh) 电机及其组装方法
US3421578A (en) Heat dissipator
US4644135A (en) Wall mounted forced air electric heater
JP2004514081A (ja) 一体化されたモーターとインペラーを備える圧縮器
US3397463A (en) Hair dryers
CN104979924A (zh) 具有流动冷却的电机
US3322931A (en) Fans
US2552470A (en) Air circulator and heater
CN108426296B (zh) 一种高效电热膜取暖器
EP0276755B1 (de) Elektrisches Heizelement für Zimmerluft-Heizgeräte
US5619612A (en) Electric air heater with cage-shaped heating element comprised of resistance alloy strips and inclined guide vanes
US3280902A (en) Heat exchanger employing two-stage cross-flow fan
JP3521262B2 (ja) 回転電機
US3807495A (en) Heat exchange apparatus
US1948759A (en) Electric heater
US2091510A (en) Motor cooling fan and blower
US1823067A (en) Electric heater
US3322932A (en) Portable electric fan heater
US3291966A (en) Heating element
US3280901A (en) Fan heater unit
CN212297031U (zh) 出风格栅及出风装置