Steamed Jacked Kettle
Principle
A heat transfer mechanism is involved in this evaporation process, which is conduction and convection, which transfers heat to the extract. A steam boiler generates heat and evaporates water from an evaporating pan containing aqueous extract. When the temperature rises, the escaping tendency of the solvent molecules increases with the increased vapour pressure, causing the solvent molecules to vaporize more easily.Construction
In a steam evaporating pan, there is an outer pan called a jacket enclosed by an inner pan called a kettle, as shown in the figure below. A space is created between the two pans through which steam passes. The kettle is constructed from several kinds of metal. The superior conductivity of copper makes it a great choice for the kettle. Some copper gets dissolved in the preparation if acidic preparation evaporates in the copper kettle. To prevent this, tinned copper kettles are used for acidic preparation. In addition to using iron for the jacket's construction, it has a low conductivity. Wearing out of iron causes rusting, which is why the iron jacket is tinned or enameled on the inside to prevent it. A steam inlet and an inlet for non-condensed gases can be found near the top of the jacket. The condensation is drained from the jacket through the bottom outlet. There is an outlet provided at the bottom for discharging product.
Working
It consists of a pot filled with evaporable solution, steam fed through the intake and condensate spouting out of the outlet, which heats the content. Mechanical stirring is required for larger volumes, while manual stirring is required for smaller volumes. Evaporation begins rapidly at the beginning. Vapour must be able to escape the chamber where evaporation occurs in order to prevent fog from forming. The room is fitted with fans to avoid condensation and to speed up evaporation. Fixed or tilted kettles are available. Up to 90 liters of capacity can be tilted in a kettle. A bottom outlet allows caught residue to be collected.Uses
- Concentrating aqueous liquids is possible with an evaporating pan.
- Thermostable liquors, such as liquorice extracts, can be concentrated with this apparatus.
Merits
- Several configurations of evaporating pans exist for small batch and large batch operations.
- Easy to operate, clean, and maintain, it is simple in construction.
- It is easy to install and maintain.
- For the construction of evaporating pans, a wide range of materials can be used, including copper, stainless steel, and aluminum.
- The contents of the pan can be stirred and the products removed easily.
Demerits
- Heat transfer is poor due to the product's natural circulation.
- As a result of solid deposition, the product may decompose.
- With increasing pan size, heating surface decreases proportionally.
- Thermally labile materials cannot be concentrated with it.
- Operating under reduced pressure is not possible.
- Organic solvents are not reclaimed.
- Vapours are directly released into the atmosphere given that the evaporating pan is open. As a result, the worker may feel discomfort.
Get subject wise printable pdf documentsView Here
No comments:
Post a Comment
Please don't spam. Comments having links would not be published.