Batch shell still process

In the batch shell still process, the still is panially filled with a set feed called a batch. The feed is then heated to the temperature required to produce a specific produa from the overhead vapors. This process is repeated each time for each produa until thcr batch reaches the maximum temperature for the range of products specified. The feed remaining in the still is then pumped out, and the still is allowed to cool. It is then refilled, and the whole process is repeated. Not only is this process time consuming, but the produa is not always of high quality. Exhibit 10-2 shows the batch shell still process, which was one of the earliest used for liquid mixture separation. 

In the continuous shell still process, several shell stills are linked in series to form a battery. Fresh feed continuously enters the first still, which is kept at the lowest temperature for the lightest overload produa. The bottoms from the first still are fed to the second still, which is kept at the temperature for the next highest boiling overhead product, and so on. The number of stills required depends on the number of produas needed. If the feed and the temperature of each still remain constant, the finished product is of satisfaaory quality. Exhibit 10-3 depicts the continuous shell still process, which is an improvement over the batch shell still operation. 

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