We often use our language in a confusing way which does not make much sense when the words are taken out of their context. The word “retort” is one such example.
- As a verb, to retort is to give a short sharp answer to someone’s comment or accusation – it can be witty but is often angry.
- In a chemistry laboratory, a retort is a blown glass vessel in the shape of a bulb with a long neck that is bent downwards. The retort is placed on a stand above a flame which heats liquid within the bulb. As vapor is driven out of the liquid, it goes up the tube, round the bend and down to be collected in another vessel where it returns to the liquid state. This is basic distillation.
- In the chemical industry, a retort is any airtight vessel used to heat substances so as to cause a chemical reaction in order to produce gases which can be collected in a separate vessel for further processing.
- Other industries use the word to describe process plant where tubes pass through a vessel and heat is transferred (either from hot gas or liquid within the tube to a colder gas or liquid within the vessel through which the tubes pass – or, vice-versa).
Retort Tubes
It is in the last context above that the term Retort Tubes makes sense and one can consider who uses them and why they might need to buy them. Most of those wishing to buy Retort Tubes are involved in processes where laboratory glass tubing would be too fragile to even be considered so; most of the tubes within an industrial retort will be made from metal.
In appearance, Retort Tubes are no different from condenser tubes, boiler tubes or the tubes used in tube and plate heat exchangers. In fact, these other three types of tube tubes could, theoretically, be called Retort Tubes.
Selection Of Metal For Retort Tubes
There are three important factors to consider when buying Retort Tubes of any type: –
- What degree of temperature will the tube be subjected to?
- What is the chemical composition of whatever is passing through the bore of the tube?
- What is the chemical composition of whatever is outside the tube?
As a minimum requirement, the Retort Tubes selected must be fully compatible with all three considerations. In addition, if you are using them as radiant tubes within a furnace bed, you should consider the heat conduction properties of the metal.
