General considerations
The operator of our ovens, kilns and furnace is unlikely to come into contact with any hazardous materials during the normal course of use. Obviously the door must be opened and goods placed within or withdrawn of the working chamber. Unless the operator causes physical damage to the door, walls or floor of the chamber no dust should arise.
In some high temperature kilns and furnaces the door and its jambs, lintels and sill may suffer thermal damage resulting in cracking. In most circumstances the cracking does not prevent the unit performing satisfactorily.
When elements need to be replaced some care must be taken but this care will generally fall within the term “Good housekeeping”.
Electrical circuitry
The codes prevailing at the time of despatch from the works will have been follwed and electrical safety is guaranteed. For units operating outside the U.K. where different norms may apply it is essential that these different requirements be stated at the time a quotation is requested.
Heating elements
All heating elements present a danger of burning the fingers if touched when hot. They should only be handled when cold and at room temperature.
The heating elements used in the low temperature ovens are wires shrouded in insulated metal tubes and present no hazard.
In the larger annealing ovens wire elements are usually placed within a metal channel through which air is blown to allow a uniform temperature to be acheived in the workspace. These elements do not present a hazard.
In furnaces and kilns operating below about 1250°C wire elements are again used. These may be supported by ceramic tubes or set in the side wall construction. The side walls may be of refractory castable, insulating firebrick or ceramic fibre board (occasionally ceramic fibre blanket). See the lining section below for details of these materials.
Above 1250°C it is necessary to use materials other than wire for the heating elements. These elements are made of electrically conducting ceramic materials. Silicon carbide is used for temperatures up to 1600°C but for temperatures above this molybdenum disilicide is used.
The market leading manufacturer of these elements is Kanthal from whom MSDS may be obtained.
Lining materials
At the lowest temperatures mineral wool is used as the insulating packing. This is the major constituent of all the units operating below about °650C. This material is made from molten slag or rock. A typical MSDS sheet is found at a manufacturer’s site.
As the temperature rises more refractory materials are used. These range through ceramic fibre blanket and board and sillimanite muffle tubes to insulating firebricks of various grades. Occasionally it is necessary to usesilicon carbide wall plates to protect side elements without causing serious element over-heating.
If you have any queries on these items please contact us and we will respond as quickly as possible.
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