DE9113933U1 - Sensor - Storage - Google Patents

Description

ZEHNDER 16199 PPS/Fk

Sensor - Storage

The present innovation relates to a device for monitoring the temperature of a heating element by means of a sensor rod that is guided at least approximately parallel to the heating element.

Heating elements are often used in physical/technical devices, heating devices, process engineering systems, etc., whereby the operating temperature of these elements usually increases to an unacceptable level when physical parameters such as the heat storage capacity, the conductivity and/or the cooling conditions of the device change.

The functionality of the device may also be impaired if the intended surface temperature of the heating device is not reached.

With heating devices, especially radiators, there is also a risk of overheating and thus of property damage if the heat transfer medium, usually water, is not present in sufficient quantities in the device.

It is therefore the object of the invention to create a device which allows unacceptable operating temperatures to be detected as early as possible and the energy supply to the heating device to be switched off and/or error messages to be generated. In addition, the device should be designed in such a way that no thermal stresses or thermal expansions impair the functional reliability of the heating device and/or the temperature sensor.

ZEHNDER .: 161"9'9 PPS/Fk

This task is solved by holding the sensor rod in a bearing so that it can move axially along its length on at least one side.

This solution has the advantage that it allows the use of standard sensor rods with commercially available temperature sensors and ensures that the device is mechanically securely attached to the physical/technical device to be heated.

The design according to claim 2 ensures a short-term response of the sensor rod, even in the case of rapidly changing temperature profiles.

The bearing specified in claim 3 is particularly simple to manufacture.

The angle-like design according to claim 4 is particularly economical.

Functionally, the device according to claim 5 meets the requirements placed on it with minimal material expenditure, especially with relatively short sensor rods.

A preferred embodiment is described in claim 6 and is particularly easy to manufacture.

The further development according to claim 7 meets all requirements and allows the use of structurally very simple sensor rods.

A particularly good heat transfer is ensured by the embodiment according to claim 8.

The embodiment according to claim 9 allows for simple assembly and is advantageous, in particular for devices that require maintenance.

ZEHNDER -%.*·. 16,199 FPS/Fk

The device according to claim 10 ensures a secure centering of the sensor rod in the bore of the bearing.

In the following, examples of the innovation are explained in more detail using drawings.

Show it:

Fig. 1 shows a simplified representation of a heating element with a vertical heating element and sensor rod,

Fig. 2a a bearing designed as a carrier for a sensor rod,

Fig. 3a an angled bearing for a sensor rod,

Fig. 4a a spring wire attached to the sensor rod for its end mounting,

Fig. 5a a bearing designed as a double ring spring for a uniform sensor rod and

Fig. 2b - Fig. 4b

to show sectional views rotated by 90° compared to Fig. 2a to 4a.

In the following, identical functional parts are provided with identical reference numbers.

In Fig. 1, 1 denotes a heating device. In the present case, this heating device is a heating element, a so-called heating cartridge. This is inserted vertically in the lower area of a heating element 9 by means of a central assembly nut 2; a heating rod 4 and a somewhat shorter sensor rod 5 running parallel to it protrude from a flange piece 3 into a heat transfer medium. The sensor rod 5

ZEHNDER „ 16 399 PPS/Fk

is guided in a bearing ring 6 and contains a commercially available temperature-dependent resistor (PTC resistor, Philips type KTY83) as a measuring element.

In the present case, the heat transfer medium consists of water; the permissible lower filling level for the heat transfer medium is designated Nl, and an impermissible level is designated N2. The amount of heat radiated radially into the air is characterized by arrows Q.

In Fig. 2a, the bearing of the sensor rod 5 can be seen in a longitudinal section in the bearing 6. The sensor rod 5 has a conical end region 5a, which is held axially displaceably in a bore 6a of the bearing 6.

The bearing 6 is connected in its lower area to the heating element 4 in a heat-conducting manner by a soldering point L. The cross-sectional view in Fig. 2b shows the corresponding proportions of the components according to Fig. 2a.

The variant Fig. 3a; 3b has an angular bearing 6', which acts in the same way as the one according to Fig. 2a; 2b.

The design according to Fig. 4a shows a spring wire 7 which engages in the end region 5a and is soldered here and at the points L in its region resting on the heating rod 4.

In a variant not shown here, the spring wire 7 engages in a form-fitting manner in a bore provided in the end region 5a of the sensor rod 5.

A double ring spring 8, 8', which is particularly suitable for uniformly designed sensor rods 5', is shown in Fig. 5a and 5b

ZEHNDER _&Iacgr; „ 16159 PPS/Fk

and is characterized by its simple manufacture and assembly.

The mechanically and thermally favorable assignment of the temperature sensor to the heating device allows it to be monitored using simple electrical and/or electronic means and at the same time serves to monitor the limit range in process controls.

The subject matter of the invention ensures safe temperature monitoring at any location, parallel to the heating element and can be adapted to a variety of commercially available heating devices.

ZEHNDER · 16199 PPS/Fk

Designation list

1 heating element

1' Mains connection (power supply)

2 Mounting nut

3 Flange piece

4 Heating element

5, 5' sensor rod

5a End area of 5 (conical)

6, 6 ' bearing

6a Drilling in 6, 6'

7 Spring wire

8, 8' ring spring (double ring spring)

9 Radiator

L Soldering points Q Radiated heat quantity

Claims (10)

ZEHNDER ■ 16>99 TPS/Fk Protection claims 1. Device for monitoring the temperature of a heating element by means of a sensor rod guided at least approximately parallel to the heating element, characterized in that the sensor rod (5; 5') is held axially displaceably along its length at least on one side in a bearing (6, 6'; 8). 2. Device according to claim 1, characterized in that the bearing (6, 6'; 8) is connected to the heating rod (4) in a heat-conducting manner. 3. Device according to claim 1 or 2, characterized in that the bearing (6, 6') is designed as a carrier and has a bore (6a). 4. Device according to claim 1 or 2, characterized in that the bearing (6, 6') is designed in an angular manner and has a bore (6a). 5. Device according to claim 1 or 2, characterized in that a spring wire (7) with at least one offset arranged in the longitudinal direction of the wire is designed as a bearing. 6. Device according to claim 1 or 2, characterized in that a spring wire in the form of an annular spring (8) is designed as a bearing. 7. Device according to claim 6, characterized in that the spring wire is designed as a double ring spring (8, 8'). ZEHNDER · 16199 FPS/Fk _M τ 8. Device according to at least one of the preceding claims, characterized in that the bearing (6, 6'; 8) is contacted with the heating element (1) by a soldered or welded connection. 9. Device according to at least one of the preceding claims, characterized in that the bearing (6, 6'; 8) is designed as a clamping flange which rests partially and force-fittingly on the heating element (1). 10. Device according to claim 1, characterized in that the sensor rod (5) is conical in the region (5a) of its bearing.