GB2142510A - Electrical heating device - Google Patents

Abstract

This invention relates to an electrical heating device, in particular heating cowl, comprising a tubular heating element 1, which is surrounded by an insulating sheath 3 and has a tubular element comprising a duct 4 into which is inserted a bendable temperature sensor, so that it leads into a required area. The duct element 4 projects out of the insulating sheath 3 and also allows of subsequent installation of the temperature sensor. The device is locatable in close proximity to and spaced from, a vessel 2, particularly a laboratory vessel such as a flask, beaker or funnel. <IMAGE>

Description

SPECIFICATION Electrical heating device The present invention relates to electrical heating devices, particularly heating cowls for heating laboratory vessels, said devices being of the kind comprising a tubular heating element and a temperature sensor.

A heating device according to the invention may utilise a tubular heating element formed by glass fibre threads or yarns in the manner of the German utility patent 82 29 508, which surround it tightly and in close contact in mesh-like manner, preferably in the form of a cowl.

It is an object of the invention to enable a bendable temperature sensor to be inserted into the heating device, in such manner that its mensuration point, in particular the sensor tip, leads to the surface of the tubular heating element.

Accordingly, the invention consists in an electrical heating device, particularly a heating cowl, comprising a tubular heating element and a temperature sensor, wherein said element is locatable in proximits to or spaced from a container which is to be heated, the heating device being surrounded by an insulating sheath and having an insertion passage for a temperature sensor, which terminates at a turn of the tubular heating element and is secured to the latter, said insertion passage projecting out of the insulating sheath.

A substantial advantage of the invention, inter alia, is that the temperature graph or the surface temperature on the heating element, may be measured. The insulation of the tubular heating element need no longer be pierced through.

Furthermore, a precise positioning of the sensor tip on the tubular heating element and thereby a more precise temperature reading, are possible with the device according to the invention. This means that unacceptable local temperature increases at the heating element are averted.

The additional advantage that the heating device according to the invention may also be equipped subsequently with a temperature sensor of the kind required derives from the fact that the measuring sensor may be inserted into a guiding tube or the passage situated therein.

In order that the invention may be more clearly understood reference is made to the accompanying drawings, which diagrammatically show one embodment thereof by way of example only, and in which: Figure 1 shows a cross-section of the electrical heating device, and Figure 2 shows a plan view of the device.

Referring now to the drawings, as shown in Figure lan electrical heating device has an electrical tubular heating element 1 in the form of a bendable heating element coil or spiral or which has a spatial form of a different kind, the heating conductor wire being centrally insulated by means of compressed powder withiq a bendable metal sheet. Heating elements of this kind are common in the trade. The shape of the heating element may also be produced in any required manner, coiled helically or otherwise, in meander form or wound, depending on the shape of the vessel which is to be heated, in particular for a chemistry laboratory, such as flasks, beakers or funnels which commonly consist of glass or other chemically impervious materials.Uncomplicated plane patterns or forms assembled from components, or several patterns or forms of manifold kinds, may also be combined.

As shown in Figure 1, the tubular heating element 1 can be located in direct contact with a vessel which is to be heated, such as a glass flask 2. It could alternatively be slightly spaced therefrom, if appropriate. The tubular heating element is surrounded by an insulating sheath 3 and an insertion duct 4 is provided which, as particularly clearly shown in Figure 2, leads to a turn of the tubular heating element and is fastened thereto. To this end, the insertion duct lies between two tubular heating element turns along at least a partial distance in an area close to its opening, and is arranged to follow said turns. It is apparent that the temperature sensor should be bendable or have a bendable jacket, so that it may follow this wound form of the tubular heating element along a partial distance at least, during insertion.The insertion duct 4 projects out of the insulating sheath 3. The latter is borne by a carrying ring (not shown).

The opening of the insertion duct or tube 4 lies as close as possible to the area of maximum temperature of the heating cowl, so that the tip of the measuring sensor or the mensuration point may detect the surface temperature in a manner appropriate to the purposes of the invention.

At its extremity facing away from its opening, the insertion duct 4 may be secured to a plate, e.g. by means of shackles, which are at least partially bent around the duct and hold the latter fast. The plate acts as a holding plate for the connections of the tubular heating element, which are installed in a terminal box, this terminal box forming part of a housing if appropriate. These members are, however, not shown.

The connecting or carrying plate may also be firmly joined to the carrying ring. If desirable, the cowl may be secured by means of carrying rings in vertically adjustable manner, e.g. on a stand. Such stand mountings are known per se.

1. An electrical heating device, particularly a heating cowl, comprising a tubular heating element and a temperature sensor, wherein said element is locatable in proximity to or spaced from a container which is to be heated, the heating device being surrounded by an insulating sheath and having an insertion passage for a temperature sensor, which terminates at a turn of the tubular heating element and is secured to the latter, said insertion passage projecting out of the insulating sheath.

2. An electrical heating device as claimed in claim 1, wherein the insertion passage is at least partially in contact with a turn of the tubular heating element.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Electrical heating device The present invention relates to electrical heating devices, particularly heating cowls for heating laboratory vessels, said devices being of the kind comprising a tubular heating element and a temperature sensor. A heating device according to the invention may utilise a tubular heating element formed by glass fibre threads or yarns in the manner of the German utility patent 82 29 508, which surround it tightly and in close contact in mesh-like manner, preferably in the form of a cowl. It is an object of the invention to enable a bendable temperature sensor to be inserted into the heating device, in such manner that its mensuration point, in particular the sensor tip, leads to the surface of the tubular heating element. Accordingly, the invention consists in an electrical heating device, particularly a heating cowl, comprising a tubular heating element and a temperature sensor, wherein said element is locatable in proximits to or spaced from a container which is to be heated, the heating device being surrounded by an insulating sheath and having an insertion passage for a temperature sensor, which terminates at a turn of the tubular heating element and is secured to the latter, said insertion passage projecting out of the insulating sheath. A substantial advantage of the invention, inter alia, is that the temperature graph or the surface temperature on the heating element, may be measured. The insulation of the tubular heating element need no longer be pierced through. Furthermore, a precise positioning of the sensor tip on the tubular heating element and thereby a more precise temperature reading, are possible with the device according to the invention. This means that unacceptable local temperature increases at the heating element are averted. The additional advantage that the heating device according to the invention may also be equipped subsequently with a temperature sensor of the kind required derives from the fact that the measuring sensor may be inserted into a guiding tube or the passage situated therein. In order that the invention may be more clearly understood reference is made to the accompanying drawings, which diagrammatically show one embodment thereof by way of example only, and in which: Figure 1 shows a cross-section of the electrical heating device, and Figure 2 shows a plan view of the device. Referring now to the drawings, as shown in Figure lan electrical heating device has an electrical tubular heating element 1 in the form of a bendable heating element coil or spiral or which has a spatial form of a different kind, the heating conductor wire being centrally insulated by means of compressed powder withiq a bendable metal sheet. Heating elements of this kind are common in the trade. The shape of the heating element may also be produced in any required manner, coiled helically or otherwise, in meander form or wound, depending on the shape of the vessel which is to be heated, in particular for a chemistry laboratory, such as flasks, beakers or funnels which commonly consist of glass or other chemically impervious materials.Uncomplicated plane patterns or forms assembled from components, or several patterns or forms of manifold kinds, may also be combined. As shown in Figure 1, the tubular heating element 1 can be located in direct contact with a vessel which is to be heated, such as a glass flask 2. It could alternatively be slightly spaced therefrom, if appropriate. The tubular heating element is surrounded by an insulating sheath 3 and an insertion duct 4 is provided which, as particularly clearly shown in Figure 2, leads to a turn of the tubular heating element and is fastened thereto. To this end, the insertion duct lies between two tubular heating element turns along at least a partial distance in an area close to its opening, and is arranged to follow said turns. It is apparent that the temperature sensor should be bendable or have a bendable jacket, so that it may follow this wound form of the tubular heating element along a partial distance at least, during insertion.The insertion duct 4 projects out of the insulating sheath 3. The latter is borne by a carrying ring (not shown). The opening of the insertion duct or tube 4 lies as close as possible to the area of maximum temperature of the heating cowl, so that the tip of the measuring sensor or the mensuration point may detect the surface temperature in a manner appropriate to the purposes of the invention. At its extremity facing away from its opening, the insertion duct 4 may be secured to a plate, e.g. by means of shackles, which are at least partially bent around the duct and hold the latter fast. The plate acts as a holding plate for the connections of the tubular heating element, which are installed in a terminal box, this terminal box forming part of a housing if appropriate. These members are, however, not shown. The connecting or carrying plate may also be firmly joined to the carrying ring. If desirable, the cowl may be secured by means of carrying rings in vertically adjustable manner, e.g. on a stand. Such stand mountings are known per se. CLAIMS

1. An electrical heating device, particularly a heating cowl, comprising a tubular heating element and a temperature sensor, wherein said element is locatable in proximity to or spaced from a container which is to be heated, the heating device being surrounded by an insulating sheath and having an insertion passage for a temperature sensor, which terminates at a turn of the tubular heating element and is secured to the latter, said insertion passage projecting out of the insulating sheath.

2. An electrical heating device as claimed in claim 1, wherein the insertion passage is at least partially in contact with a turn of the tubular heating element.

3. An electrical heating device as claimed in claim 1 or 2, wherein the insertion passage opens into or close to the area of the maximum temperature of the tubular heating element.

4. An electrical heating device, substantially as hereinbefore described with reference to the accompanying drawings.