US3716693A - Tubular heating element - Google Patents

Tubular heating element Download PDF

Info

Publication number
US3716693A
US3716693A US00143990A US3716693DA US3716693A US 3716693 A US3716693 A US 3716693A US 00143990 A US00143990 A US 00143990A US 3716693D A US3716693D A US 3716693DA US 3716693 A US3716693 A US 3716693A
Authority
US
United States
Prior art keywords
heating element
insulating material
tubular
tubular heating
additional insulating
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
US00143990A
Other languages
English (en)
Inventor
R Bleckmann
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 US3716693A publication Critical patent/US3716693A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/40—Heating elements having the shape of rods or tubes
    • H05B3/42—Heating elements having the shape of rods or tubes non-flexible
    • H05B3/46—Heating elements having the shape of rods or tubes non-flexible heating conductor mounted on insulating base
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/10—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor
    • H05B3/18—Heating elements characterised by the composition or nature of the materials or by the arrangement of the conductor the conductor being embedded in an insulating material
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B3/00—Ohmic-resistance heating
    • H05B3/40—Heating elements having the shape of rods or tubes
    • H05B3/42—Heating elements having the shape of rods or tubes non-flexible
    • H05B3/48—Heating elements having the shape of rods or tubes non-flexible heating conductor embedded in insulating material

Definitions

  • An electrical tubular heating element comprises an outer tube of metal and at least one electrical heating resistance, which is arranged in the outer tube.
  • the zone adjacent to the inner wall of the outer tube is filled with magnesium oxide or another insulating material with a high melting point.
  • Immediately adjacent to the heating resistance at least one layer or glass or another additional insulating material is provided so that when the temperature of the outer tube reaches a certain maximum value, a leakage current sufficient for switching off the tubular heating element flows between the coils of the heatingresistance or a wire core arranged inside this heating resistance.
  • the present invention relates to an electrical tubular heating element in which in a casing tube one or more heating resistances are accommodated which are insulated from the case tube by means of magnesium oxide or another high melting point insulating material and whose casing tube temperature may not exceed a maximum value chosen in accordance with the actual tube material and the purpose of use.
  • Such tubular heating elements are used in large numbers for heating liquids, more particularly water, for example in washing machines, dish washing machines or other liquid heaters or as heating elements in baking ovens, electric stoves, grilling devices etc. If, owing to some reason or other the removal of heat from the tube surface is hindered, for example, the build up of fur or the formation of foam in the case of washing machines or owing to running dry" due to control errors, such as in dish washing machines, the temperature in the interior of the tubular heating element rises to such a degree that the heating resistances begin to melt. This burning through of the tubular heating body can on the one hand occur in such a manner that an' arc, which is immediately extinguished, is only formed between the molten, ends of the heating resistance.
  • the melting open of the outer tube leads to the liquid penetrating into the interior of the tubular heating element so that an electrical connection is produced with the melted open end of the heating helix, which is still connected to the current, with the known dangers.
  • tubular heating elements sometimes burn through to' the outside and some times to the inside has not, as far as is known, been systematically investigated in the literature. It is to be assumed that the metal vapors produced on the formation of an arc penetrate into cracks or pores of the insulating material and become deposited there until an electrically conducting bridge is formed with the outer casing and then a corresponding arc is produced with the outer casing.
  • the invention is based upon the discovery that, providing certain dimensions are assumed, which, however, can be readily determined by one skilled in the art in accordance with a particular tubular heating element type and purpose of use, it is possible to produce a short circuit between the heating element coils or toa core wire arranged in the interior of the tubular heating element, when the temperature of the outer tube of the tubular heating element exceeds a certain determined value. In this respect it is of no importance whether this value is high or low.
  • a tubular heating element temperature of as low as 300 C may not be permissible. in other cases, in the case of radiative heaters, a substantially higher temperature, for example 900 C, can be tolerated.
  • an electrically conducting core which for example is connected with one end of the heating helix, there are in accordance with whether the heating coil is wound with a small or a large slope two effects which are to be distinguished from each other. If the coils of the heating helix are very close together, the additional insulating material melts over a large surface on overheating of the outer tube. There results owing to this melting a corresponding leakage current, which after reaching a certain level leads to actuation of an overcurrent device. After solidification of this molten material the heating element can be used again.
  • the coils of the heating element have, however, a greater distance from each other, there is in the case of an overheating at a localized area, a breaking through of the,additional insulating material.
  • the metal vapors occurring in the case of the formation of the arc become deposited in the path of the break-through and bring about a permanent short circuit.
  • Such heating elements can never be used again. Since the additional insulating material is not used at a position adjacent to the heating helix and not adjacent to the outer tube, in every case it only comes to a short circuit between the coils of a helix or between the coils of several heating helices or between a heating coil and the core wire, which may be provided in the interior of the tubular heating element, but not with the outer tube.
  • FIG. 1 is a section of the connection end of a tubular heating element with a conducting inner core.
  • FIG. la is a cross-section of the tubular heating body in'accordance with FIG. 1 along the line IaIa of FIG.
  • FIG. 2 is a section of a connection of a tubular heating body with a glass fiber fabric hose drawn over the heating helix.
  • FIG. 3 is a section of a connection end of a tubular heating element with a thickly wound heating helix.
  • FIG. 4 is a section through a container with a tubular heating element arranged in a vertical fashion, which serves as a check method.
  • FIG. 5 is a section through a container with a tubular ,heating element arranged so as to be lying horizontally.
  • FIG. 6 is an illustrative diagrammatic view of a washing machine.
  • FIG. 7 is a section through an embodiment of a tubular heating body with a double inner core.
  • FIG. 8 is a section-through an embodiment of a tubular heating body which comprises two heating helices and which can be connected in different power stages.
  • tubular heating elements are shown on a somewhat enlarged scale.
  • the actual dimensions generally correspond to the conventional dimensions of tubular heating bodies as are found in household devices.
  • thetubular heating bodies comprise a casing tube 1 which is made of metal, more particularly stainless steel and which is filled with magnesium oxide 2.
  • magnesium oxide it is possible to use another refractory material. Since, however, numerousrequirements, more particularly as regards a good heat transfer, are to be made as regards theinsulating material, the selection is fairly small.
  • a heating resistance in the form of a heating helix 3 is embedded and a conducting inner core 5, the latter in the form of a piece of wire,'is inside the helix.
  • a connecting bolt 6 has a reduced diameter part 7, on which the end of the heating helix is placed and which is connected'with the latter in an electrically conducting manner.
  • a bead 8 of insulating material serves for closing the end of the tubular heating body or element.
  • the other end of the tubular heating element is 'similarly'constructed.
  • the inner core 5 is not in electrical connection with the associated connecting bolt 6.
  • the tubular heating'body itself can for example .be bent in the form of a U or in the form of a W.
  • the thickness of the glass fiber fabric and the melting point of the glass must, as appears from the later description, be selected in a certain manner to suit the permissible maximum temperature value permissible of the casing tube 1, so that a basic objective of the invention is fulfilled.
  • the tubular heating element In order to compress the magnesium oxide the tubular heating element is generally mechanically pressed so that, as can be seen from FIG. la, it has an oval cross-section. It is essential that the zone 2a adjacent to the inner wall of the outer tube 1 exclusively contains the high melting point magnesium oxide.
  • the embodiment shown in FIG. 2 differs from that shown in FIG. 1 in that instead of the inner core 5 and the glass fiber fabric hose 9 a glass fiber fabric hose 11 is provided which surrounds the heating helix 4, which has a lower angle of winding than the heating helix 3, and as a result, the individual coils are closer together.
  • the heating helix 4 is arranged on a glass fiber hose 9, which surrounds a conducting inner core 5.
  • the heating helix 4 itself is surrounded by means of a glass fiber fabric hose 1!. Its ends 40 are connected respectively with the reduced diameter portion 7 of the associated connecting bolt 6.
  • the whole arrangement is, as is shown in the preceding figures, accommodated in a casing tube 1, into which magnesium oxide 2 is shaken.
  • a tubular heating element in accordance with FIGS. 1 and 2 is overheated, for example owing to the voltage being increased in stages or owing to it not being possible for the heat produced to be conducted from the casing tube 1, at a specific temperature value of the casing tube 1 the glass fiber fabric hose 9 or the glass fiber fabric hose l1 begins to become soft or to melt.
  • the melting temperature of the glass fiber fabric hose 9 or 11 is, as already mentioned, so chosen that in the zone lying adjacent to the heating helix this temperature is reached when the casing tube 1 reaches the permissible maximum temperature value.
  • the high specific resistance value of glass substantially decreases so that a substantial leakage current flows between the coils of the heating helices 3 or 4, and, if such is provided, to the inner core 5.
  • This leakage current serves for a further heating of the glass melt so that a shortcircuit occurs.
  • This shortcircuit ensures that the casing tube does not reach a temperature lying above the maximum permissible temperature value. Furthermore, it is reliably ensured that an arc is not formed extending fromthe heating helix 3 or 4 to the casing tube 1, by which the casing tube 1 would be melted open.
  • the helix 3 is wound under tension on a glass fiber fabric hose 9 placed on the inner core 5, at the initiation of softening of the glass fiber fabric any one of the coils of the heating helix 3 will press the glass material to the side, so that a shortcircuit with the inner core5 is encouraged.
  • a heating element 13 constructed in accordance with FIG. 2, is arranged vertically.
  • the container 12 is filled with water, it being possible to lower the water from the level 14 over the level 15 to the level 16.
  • the connection ends 17 of the tubular heating body 13 are arranged and the bottom of the container 12. As long as the water level is held at the level 14, there are normal operation conditions, as occur for example in the case of a liquid heater. If, in the case of the use of a conventional tubular heating element, for example owing to a control error, the water level sinks to the level 15, the end, extending above the level 15, of the tubular heating element 13 becomesred hot.
  • the tubular heating body will burn through, and, as mentioned initially, in one third to two thirds for all cases, the burning will be towards the outside with a melting open of the casing tube. If the liquid level increases again, an electrically conducting connection is produced with the melted open end of the heating helix. Touching the water connections of the liquid heater can then be dangerous to life. In those cases in which the container 12 is made of plastics material, melting of the plastics material housing may take place owing to the radiation temperature. More particularly in the case of dish washing machines the plastics material housing may be burnt out. This has occurred again and again despite substantial safety measures being adopted.
  • the tubular heating body constructed in accordance with the invention what happens is substantially different. If the water level sinks to the level 15, the temperature of the part, which is partially dry and lies above the water level 15, of the tubular heating element 13 rises, in the particular embodiment concerned, to 760 C. At this tubular casing temperature the conductivity of the glass fiber fabric hose 1] is so large that this part is substantially shortcircuited. The temperature dropped suddenly to room temperature. It was only shortly above the water level 15 that a piece, about 5 mm long, of the tubular heating element 13 continued to be red hot, because at this position in the interior the temperature was not yet sufficient for shortcircuiting. As a result of the shortened heated length of the tubular heating body the current consumption increased.
  • FIG. 3 only serves to illustrate the fact that both measures, that is to say the conducting inner core 5 with the glass fiber fabric hose 9 and the glass fiber fabric hose l1 surrounding the heating helix can be combined in a single embodiment.
  • a local overheating of a tubular heating element can occur for a number of different reasons.
  • a part of the heating element can-lie in current flow regions in which owing to eddy effects considerable foam formation occurs.
  • tubular heating elements which give up their heat to the air owing to radiation or convection owing to hinderance in the air flow or other reasons the discharge of heat at a certain position of the tubular heating element can be worse than at the other position.
  • Devices which normally operate perfectly under normal conditions can in accordance with the manner in which they have been installed by the user, have different heat discharge characteristics.
  • the tubular heating element burns through sooner or later at the overheated position.
  • the overheated position is shortcircuited, while the tubular heating body continues to function normally along the remainder of its length.
  • the surface loading of the resistance wire should be less than 20 to 25 watt per square centimeter, and preferably between 10 to 20 watt per square centimeter. In the case of tubular heating elements which cannot be switched on again, the surface loading is chosen so as to be between 25 and 40 watt per square centimeter or higher.
  • the thickness of the additional insulating layer is to lie between 0.2 and 0.5 mm.
  • the heating coil with the inner core is to be electrically connected at the lower connection, so that at the upper connection there is the greatest potential difference between the heating helix and the inner coil.
  • FIG. 5 For explanation of this construction reference is made to FIG. 5.
  • the end of the heating helix 3 is directly placed on the inner core 5 and connected with it electrically, for example by welding.
  • the associated connection 6 can consist of the inner core 5 continued outwardly.
  • the end of the glass fiber fabric hose 9 does not extend quite as far as the connection bolt 6.
  • the inner core 5 ends at a distance from the associated connection bolt 6.
  • the drawn out end of the glass fiber fabric'hose 9 provides suitable insulation between the heating helix 3 and the inner core 5.
  • FIG. 6 shows a washing machine 26 with a drum 27 and a liquid sump container 28.
  • a U-shaped bent tubular heating element 29 is arranged in a conventional manner in a horizontal position in the liquid sump container 28.
  • the tubular heating element 29 is bent at 31 in the form of an offset in an upward direction. If the washing machine runs dry, the tubular heating body is shortcircuited at the position 31 as soon as the liquid level sinks below the height of this position. It is thus ensured that the remaining length of the tubular heating element does not become red hot.
  • two inner cores 32, 33 are provided, which are insulated fromeach other by means of wound on glass silk or suitable glass hoses 34, 35, this insulation also serving to insulate the cores from the enclosing heating helix 3.
  • the one end of each of the inner cores 32, 33 is connected with an associated connection bolt 6.
  • the two ends 30 of the heating helix 3 are mounted on the reduced diameter parts 7 of the associated bolt 6. If now at any position in the tubular heating element overheating should occur, the glass layer between the two inner cores 32, 33 becomes conductive at this position.
  • a safety device connected in series with the tubular heating element brings about immediate switching off of the tubular heating element. Since in the case of this arrangement the resistance wire of the heating helix 3 is generally not damaged and after solidification of the molten glass full insulation comes into being again, such a tubular heating element can be used repeatedly.
  • tubular heating elements As is known it is very difficult to produce tubular heating elements with a high resistance by unit length. Generally in the case of tubular heating elements with 6 to 9 mm external diameter the possibility of production is limited-to approximately 600 ohms per meter. The reason for this is to be found in that in the case of such meter resistances it is necessary already to use resistance wires with a diameter of 0.15 mm, whose working in the helically wound form is very difficult. if any support or binding means are used for the helix, such means evaporate at the operating temperature so that the insulation value becomes poorer. in this connection use has already been made of asbestos for example with a corresponding binding material or means.
  • FIG. 8 of a tubular heating element two heating helices 36, 37 are provided which are each provided with glass fiber spun on material 42.
  • the helix 36 is connected electrically with the connecting tag 38 and the heating helix 37 is connected electrically with the connecting tag 39.
  • the other end of the heating helices 36 and 37 is mounted on a bolt 41. If these ends, as shown, are insulated off and the bolt 41 serves as a connecting bolt, then only the heating helix 36 or only the heating helix 37 or both heating helices 36 and 37 can be connected with voltage. This provides for a simple switching of power in this manner.
  • tubular heating elements which have a one-sided connection are already known, it is difficult to realize such constructions with the conventional external diameters 6 to 9 mm. This can be carried out, however, with the construction in accordance with FIG. 8 readily.
  • Glass silk and glass fabric provide in the case of the embodiment in accordance with the invention for a very simple and easy workability.
  • spun stone wool is also suitable.
  • enamel layers more particularly in the case of embodiments with inner cores, are suitable.
  • the inner core then consists of a wire which consists of unalloyed steel which has a fired enameled coating. in this manner it is possible to achieve particularly low costs of production.
  • tubular heating elements described above have just as good an overall insulation resistance as normally constructed tubular heating elements. This is to be attributed to the fact that for the level of the insulation resistance in the case of tubular heating body the coldest zones of the insulating mass are decisive.
  • an outer metal tube and at least one electrical resistance coil heating element having electrical terminals mounted and electrically insulated from the outer tube to define a heating zone therebetween; a high melting point first insulating material filling said zone, said first insulating material being refractory and heat conductive; an additional insulating material arranged immediately adjacent the heating element, said additional insulating material having a lower softening and melting point than said first insulating material and being more electrically conductive when so softened and melted, the point of softening and melting being so chosen that a fiow of current suitable to short circuit an over-heated portion of the resistance coil takes place through the additional insulating material when the temperature immediately adjacent to the heating element reaches a value at which the temperature of the outer tube exceeds the permissible maximum value.
  • the resistance wire of the heating element has a thread-like glass material spun round it.
  • the tubular heating element of claim 1 including insulating beads for closing the ends of the outer tube around the electrical terminals.

Landscapes

  • Resistance Heating (AREA)
US00143990A 1970-05-21 1971-05-17 Tubular heating element Expired - Lifetime US3716693A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
AT453570A AT299400B (de) 1970-05-21 1970-05-21 Elektrischer Rohrheizkörper

Publications (1)

Publication Number Publication Date
US3716693A true US3716693A (en) 1973-02-13

Family

ID=3565282

Family Applications (1)

Application Number Title Priority Date Filing Date
US00143990A Expired - Lifetime US3716693A (en) 1970-05-21 1971-05-17 Tubular heating element

Country Status (12)

Country Link
US (1) US3716693A (de)
AT (1) AT299400B (de)
BE (1) BE767472A (de)
CA (1) CA935217A (de)
CH (1) CH530146A (de)
DE (1) DE2124028C3 (de)
FR (1) FR2090181B1 (de)
GB (1) GB1340024A (de)
NL (1) NL7107024A (de)
NO (1) NO131225C (de)
SE (1) SE373260B (de)
ZA (1) ZA713260B (de)

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4092520A (en) * 1976-12-16 1978-05-30 Baxter Travenol Laboratories, Inc. Leakage current thermostat
US4129774A (en) * 1975-08-28 1978-12-12 Hitachi Heating Appliances Co., Ltd. Filling materials for heating elements
US5774627A (en) * 1996-01-31 1998-06-30 Water Heater Innovation, Inc. Scale reducing heating element for water heaters
US5907663A (en) * 1998-06-24 1999-05-25 Lee; Wen-Ching Far-infrared electric heater
EP1233650A1 (de) * 2001-01-24 2002-08-21 Leister Process Technologies Heisslufteinrichtung
US20030146204A1 (en) * 2000-03-10 2003-08-07 Simon Kaastra Heating element, liquid container and method for detecting temperature changes
US20060249508A1 (en) * 2005-04-25 2006-11-09 Bleckmann Gmbh & Co., Kg Tubular heating element with conical heating coil
US20080236098A1 (en) * 2007-03-28 2008-10-02 Bevcorp Llc Beverage filling machine lock lever and methods for use
US20080237210A1 (en) * 2007-03-30 2008-10-02 Illinois Tool Works Inc. Hot melt adhesive hose assembly with thermal fuse link
US20080236215A1 (en) * 2007-03-28 2008-10-02 Bevcorp Llc Beverage filling machine lock lever and methods for use
US7449661B1 (en) 2006-11-03 2008-11-11 Bench Steven D In-pipe heat trace system
US20110068098A1 (en) * 2006-12-22 2011-03-24 Taiwan Textile Research Institute Electric Heating Yarns, Methods for Manufacturing the Same and Application Thereof
US20110309068A1 (en) * 2006-01-30 2011-12-22 Jie-Wei Chen Heating element for a hot air device
US20130251355A1 (en) * 2012-03-23 2013-09-26 Samsung Electronics Co., Ltd. Coating composition, heater of washing machine having the same, and coating method for the heater
US20140355971A1 (en) * 2013-05-30 2014-12-04 Osram Sylvania Inc. Infrared Heat Lamp Assembly
US9113501B2 (en) 2012-05-25 2015-08-18 Watlow Electric Manufacturing Company Variable pitch resistance coil heater
RU2622392C1 (ru) * 2015-12-24 2017-06-15 Марат Тагирович Гареев Трубчатый электронагреватель

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2645939C3 (de) * 1976-10-12 1985-08-01 Fa. Friedrich Würth, 7000 Stuttgart Elektrische Heizwendel mit Fangseele sowie Verfahren zu ihrer Herstellung
DE3026545A1 (de) * 1980-07-12 1982-02-04 E.G.O. Elektro-Geräte Blanc u. Fischer, 7519 Oberderdingen Elektrisch betriebenes haushaltsgeraet
DE3204875C2 (de) * 1982-02-12 1985-02-07 Elpag Ag Chur, Chur Rohrheizkörper mit einer Überlastungssicherung
DE3438413A1 (de) * 1984-10-19 1986-04-24 Elpag Ag Chur, Chur Rohrheizkoerper
DE3601307A1 (de) * 1986-01-17 1987-07-23 Siemens Ag Sicherungssystem gegen uebertemperaturen von stromfuehrenden elektrischen leitern
DE4014753A1 (de) * 1990-05-08 1991-11-14 Elpag Ag Chur Rohrheizkoerper mit sicherung

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1073657B (de) * 1960-01-21 General Electric Company, Schenectady, N. Y. (V. St. A.) Biegsamer drahtartiger isolierter elektrischer Heizkörper
US2880297A (en) * 1955-06-22 1959-03-31 Gen Electric Electric heating units
FR1154014A (fr) * 1955-06-22 1958-04-01 Thomson Houston Comp Francaise éléments chauffants électriques perfectionnés et leur mode de fabrication

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4129774A (en) * 1975-08-28 1978-12-12 Hitachi Heating Appliances Co., Ltd. Filling materials for heating elements
US4092520A (en) * 1976-12-16 1978-05-30 Baxter Travenol Laboratories, Inc. Leakage current thermostat
US5774627A (en) * 1996-01-31 1998-06-30 Water Heater Innovation, Inc. Scale reducing heating element for water heaters
US5907663A (en) * 1998-06-24 1999-05-25 Lee; Wen-Ching Far-infrared electric heater
US6919540B2 (en) * 2000-03-10 2005-07-19 Ferro Techniek Holding B. V. Heating element, liquid container and method for detecting temperature changes
US20030146204A1 (en) * 2000-03-10 2003-08-07 Simon Kaastra Heating element, liquid container and method for detecting temperature changes
EP1233650A1 (de) * 2001-01-24 2002-08-21 Leister Process Technologies Heisslufteinrichtung
US6683285B2 (en) 2001-01-24 2004-01-27 Leister Process Technologies Hot-air device
EP1701237A2 (de) * 2001-01-24 2006-09-13 Leister Process Technologies Heizelement
EP1701237A3 (de) * 2001-01-24 2011-11-16 Leister Process Technologies Heizelement
US20060249508A1 (en) * 2005-04-25 2006-11-09 Bleckmann Gmbh & Co., Kg Tubular heating element with conical heating coil
CN1856192B (zh) * 2005-04-25 2010-12-01 布莱克曼两合公司 具有圆锥形电热螺旋线的管形加热体
US7538301B2 (en) * 2005-04-25 2009-05-26 Bleckmann Gmbh & Co., Kg Tubular heating element with conical heating coil
US20110309068A1 (en) * 2006-01-30 2011-12-22 Jie-Wei Chen Heating element for a hot air device
US7449661B1 (en) 2006-11-03 2008-11-11 Bench Steven D In-pipe heat trace system
US20110068098A1 (en) * 2006-12-22 2011-03-24 Taiwan Textile Research Institute Electric Heating Yarns, Methods for Manufacturing the Same and Application Thereof
US20080236215A1 (en) * 2007-03-28 2008-10-02 Bevcorp Llc Beverage filling machine lock lever and methods for use
US7938152B2 (en) 2007-03-28 2011-05-10 Bevcorp, Llc Beverage filling machine lock lever and methods for use
US7967038B2 (en) 2007-03-28 2011-06-28 Bevcorp Llc Beverage filling machine lock lever and methods for use
US20080236098A1 (en) * 2007-03-28 2008-10-02 Bevcorp Llc Beverage filling machine lock lever and methods for use
US7732736B2 (en) * 2007-03-30 2010-06-08 Illinois Tool Works Inc. Hot melt adhesive hose assembly with thermal fuse link
US20080237210A1 (en) * 2007-03-30 2008-10-02 Illinois Tool Works Inc. Hot melt adhesive hose assembly with thermal fuse link
US20130251355A1 (en) * 2012-03-23 2013-09-26 Samsung Electronics Co., Ltd. Coating composition, heater of washing machine having the same, and coating method for the heater
US9113501B2 (en) 2012-05-25 2015-08-18 Watlow Electric Manufacturing Company Variable pitch resistance coil heater
US20140355971A1 (en) * 2013-05-30 2014-12-04 Osram Sylvania Inc. Infrared Heat Lamp Assembly
US10264629B2 (en) * 2013-05-30 2019-04-16 Osram Sylvania Inc. Infrared heat lamp assembly
RU2622392C1 (ru) * 2015-12-24 2017-06-15 Марат Тагирович Гареев Трубчатый электронагреватель

Also Published As

Publication number Publication date
AT299400B (de) 1972-06-12
GB1340024A (en) 1973-12-05
FR2090181B1 (de) 1973-06-08
ZA713260B (en) 1972-08-30
NL7107024A (de) 1971-11-23
SE373260B (de) 1975-01-27
CA935217A (en) 1973-10-09
NO131225C (de) 1975-04-23
DE2124028C3 (de) 1981-03-12
FR2090181A1 (de) 1972-01-14
BE767472A (fr) 1971-10-18
DE2124028A1 (de) 1971-12-02
NO131225B (de) 1975-01-13
CH530146A (de) 1972-10-31
DE2124028B2 (de) 1979-01-25

Similar Documents

Publication Publication Date Title
US3716693A (en) Tubular heating element
US3912905A (en) Electric resistance heating device
JPS6180788A (ja) 料理器具用ラジアントヒータ
GB1569305A (en) High pressure discharge lamp
US4697069A (en) Tubular heater with an overload safety means
EP0429244A2 (de) Elektrische Strahlungsheizgeräte
US1835602A (en) Electrical heating device
US2649532A (en) Water heater apparatus
US2116228A (en) Method and apparatus for cleaning ends of insulated electric wires
AU626943B2 (en) Radiant element
US2074985A (en) Electric cooker
US2231236A (en) Heating means
US2680183A (en) Enclosed heating element
US4010350A (en) Electric heating elements
US6300604B1 (en) Radiant electric heater
US2302808A (en) Electric heater
CN210641091U (zh) 一种加热装置
US2923802A (en) Multiple element heating units
US1237592A (en) Electrical heating unit.
US2654820A (en) Electric immersion heater
EA004666B1 (ru) Нагревательный кабель с многослойным строением
US2227159A (en) Electric heater
JP2950056B2 (ja) シーズヒータ及びシーズヒータを有する加熱装置
RU2400943C1 (ru) Электрический нагревательный элемент с термопредохранителем (варианты)
US2245085A (en) Liquid heater