I’m reaching out again with questions regarding the jacket of the reaction kettle

When switching the heating (cooling) medium, it is not a good idea to first blow out the jacket with compressed air.

The two sets of utility systems are determined by the process requirements; they need not necessarily be circulating water and chilled water – steam could also be used. Generally, two sets are provided, as batch operations are common in such processes, which involve heating first and then cooling, or cooling to allow solids to precipitate, or processes related to starting up and shutting down the equipment. The red-boxed branches are likely intended to handle these start-up and shutdown scenarios, or they may have been designed from a process perspective – it isn’t strictly necessary to design them in this way

What was said on the third floor is correct; in typical designs, it is avoided to use the same medium for chilled brine and steam water, and this approach is adopted only when it is unavoidable

1. Cold precipitation is carried out in two stages within one reactor; separation is required, which necessitates the use of an additional reactor as well as operations for transferring the contents from one reactor to another； If it is frozen directly without separating the vessels, there are issues related to energy consumption; moreover, if the inner walls of the vessels are lined with enamel, large temperature differences can cause the enamel to crack easily ； If the pot is used for crystallization, putting it directly into the freezer is not conducive to obtaining proper crystal formation of the material ； Liquid is discharged twice to push the refrigerant back, preventing cross-contamination: cooling water from mixing with brine, and brine from mixing with circulating water, which would dilute the concentration of the brine and contaminate the cooling water

In such a kettle, after jacket cooling, some residual cooling water seeps into the brine, and brine seeps into the cooling water, as there are recessed areas at the bottom where liquid can accumulate； This can be seen when disassembling the reactor; a 5000L reactor probably has 30-50 kilograms of liquid accumulated in it. These are the reactors I’ve worked with, and it’s possible that in some reactors water is introduced to the lowest point or pressure is applied back, but this might conflict with the operation of the bottom valve, after all, there is also space needed for insulation

From the diagram, it seems there are three different fluids: circulating water, chilled water, and condensate (steam). These are typically different fluids selected based on the process requirements to enable temperature control. It appears that this approach may lead to mixing of these fluids, which is a drawback

Modern reactor designs can feature multiple layers of coils; it is recommended to use two layers of coils inside and one layer in the jacket, which facilitates effective separation and prevents the media from contaminating each other.

……From the diagram, it seems that three types of media are required for the jacket of the reactor: circulating cooling water, chilled brine, and steam (with a condensate trap). The two pipes marked in red are likely used to drain the circulating water and chilled brine before switching between media, in order to prevent mixing of these media; however, this approach may not necessarily yield good results.:)

I understand. Thank you all for helping me answer my questions