Thermoelement

• US 20110292968A1
• Filed: 05/11/2011
• Published: 12/01/2011
• Est. Priority Date: 05/11/2010
• Status: Active Grant

• Current Assignee: Innovatherm PROF Dr Leisenberg GmbH & Company KG
• Original Assignee: Innovatherm PROF Dr Leisenberg GmbH & Company KG
• Inventors: Uhrig, Wolfgang, Maiwald, Detlef, Mnikoleiski, Hans-Peter, Krieg, Peter, Hoßach, Christian
• Granted Patent: US 8,684,598 B2
• Time in Patent Office: Days
• US Class Current: 374/179
• CPC Class Codes: G01K 1/08 Protective devices, e.g. casings
• CPC Class Codes: G01K 1/14 Supports; Fastening devices; Arrangements for mounting thermometers in particular locations
• CPC Class Codes: G01K 13/02 for measuring temperature of moving fluids or granular materials capable of flow
• CPC Class Codes: G01K 7/02 using thermoelectric elements, e.g. thermocouples

Abstract

A thermoelement (1) for measuring the temperature in gaseous or fluid media by means of one or more thermocouples (4) comprising wires of different metals welded together which give off a resulting electrical voltage when heated and are configured as a measuring insert (2) arranged in an insulating rod (3) disposed in a heat-resistant protective tube (11) that can be connected to a connection head (6), the protective tube being wholly or partially surrounded by a holding tube (21). To prevent a high input of heat which has an unfavourable effect on a temperature measurement, the holding tube (21) is supported against the protective tube (11) at a radial distance from the protective tube (11), and a heat-resistant trace (31) and optionally an insulating material (33) are inserted between the protective tube (11) and the holding tube (21), and the holding tube (21) is attached to the connection head (6) and/or the protective tube (11) in one or both end areas and is provided with thermal insulation.

Claims

1. A thermoelement (1) for measuring the temperature of gaseous or fluid media by means of at least one or more thermocouples (4) comprising wires made from different metals welded together which give off a resulting electrical voltage when heated, and are configured as a measuring insert (2) disposed in an insulating rod (3) inserted in a heat-resistant protective tube (11) connected to a connection head (6), the protective tube (11) being at least partially surrounded by a holding tube (21),

wherein

the holding tube (21) is supported around the protective tube (11) at a radial distance from the protective tube (11), and a heat-resistant trace (31) and an disposed material (33) are inserted between the protective tube (11) and the holding tube (21), and the holding tube (21) is attached to at least one of the connection head (6) and the protective tube, (11) in at least one end area thereof with thermal insulation.

2. The thermoelement in accordance with claim 1,

wherein

the trace (31) is of a selected one of a heat-resistant and ceramic material.

3. The thermoelement in accordance with claim 1,

wherein

the trace (31) is arranged in a helical profile between the protective tube (11) and the holding tube (21).

4. The thermoelement in accordance with claim 1,

wherein

the trace (31) is attached to a selected one of an outer jacket surface of the protective tube (11) and an inner jacket surface of the holding tube (21).

5. The thermoelement in accordance with claim 1,

wherein

an air gap (30) between the protective tube (11) and the holding tube (21) is closed at both ends to hold the trace (31) or is constricted to provide a clearance smaller than the diameter of the trace (31).

6. The thermoelement in accordance with one of the claim 1,

wherein

the holding tube (21) disposed between the connection head (6) and a support leg (22) is divided into two sections (21′

, 21″

), and a coil compression spring (32) is disposed between the two sections (21′

, 21″

) of the holding tube (21) such that the coil compression spring (32) is supported against the sections (21′

, 21″

).

7. The thermoelement in accordance with claim 6,

wherein

the end areas of the coil compression spring (32) are connected to the two sections (21′

, 21″

) of the holding tube (21) by means of crimping.

8. The thermoelement in accordance with claim 6,

wherein

the trace (31) is disposed in the section (21′

) of the holding tube (21) attached to the connection head (6) and in end areas thereof, is connected to the connection head (6) and the corresponding section (21′

) of the holding tube (21), by a selected one of crimping or is glued onto a selected one of the section (21) and the protective tube (11).

9. The thermoelement in accordance with claim 1,

wherein

the protective tube (11) is provided on a side facing the measuring insert (2) with a radially projecting support leg (22) comprising a flange (23) and is attached thereto in a thermally insulated manner by means of one or more insulating or sealing discs (24) disposed between the support leg (22) and the measuring insert (2).

10. The thermoelement in accordance with claim 1,

wherein

the holding tube (21) is connected to the connection head (6) on a side thereof facing the connection head—

by means of at least one insulating or sealing disc (24) located between the connection head (6) or the holding tube (21).

11. The thermoelement in accordance with one of claim 1,

wherein

the holding tube (21) is supported against the protective tube (11) on a side facing the connection head (6) in a torsionally rigid arrangement.

12. The thermoelement in accordance with claim 11,

wherein

the holding tube (21) is provided with a partially open flange (28) with at least one groove (29) into which the protective tube (11) engages with an axially projecting shoulder (12) for each groove, located in the outer edge area.

13. The thermoelement in accordance with claim 1,

wherein

the protective tube (11) is of a gas-tight, heat resistant material.

14. The thermoelement in accordance with claim 13, wherein the heat resistant material comprises silicon carbide.