Issues with hot water tanks for converter heat exchange and rectifier reboilers
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Is it better to use one hot water tank for heat exchange in the converter and heating in the rectification reboiler, or two hot water tanks?
There is a book titled \"Polyvinyl Chloride Technology\" available at Beijing Chemical Bookstore, which provides a very comprehensive overview; the specific manufacturing processes are described in detail
Generally, the design consists of one unit, but in terms of operation, it’s better to have two. Reason: The temperature of the hot water used in distillation is too high, which is not conducive to the distillation process. If no change is needed, using one can increase the operating pressure of the distillation system, reduce the amount of cooling required, and make full use of heat.
It’s better to share one hot water tank: 1. Lower investment cost (no need to discuss)； 2. The synthesis of vinyl chloride is an exothermic reaction; the temperature of the hot water returning from the converter rises. The reboiler used for refining requires heat absorption, which causes the temperature of the returning hot water to drop. After mixing in the same hot water tank, this reduces the amount of steam needed to heat the tank, thereby saving energy. It is important to note: how to ensure uniform mixing? Prevent temperature fluctuations.
What we use is: the distilled hot water returns to the top of the hot water tower; the hot water from the converter cycle returns to the middle and lower parts of the hot water tower; the return water from the hot water preheater goes to the middle part of the hot water tower. The steam is sprayed with distilled return water (with packing at the upper part)
We use a hot water tank.
It’s better to use one that is of good quality; the hot water can also be used for heating or warming up the bath water
I strongly agree with Senior Wang *neng’s opinion; it’s very accurate. In practice, few people actually use two of them
It is better to use two hot water tanks, mainly because: using low-temperature water for distillation helps to reduce coking in the bottom of the distillation tower caused by high temperatures, thereby stabilizing distillation control； The hot water from the converter can be used as make-up water for the distillation hot water tank, and the utilization of thermal energy is essentially the same as in the case of using a single hot water tank. The main drawback of using two hot water tanks is the relatively high investment cost. This post was last edited by shizhiyong001 on 2009-3-16 10:49.]
From the perspective of process management, it is better to install two hot water tanks. The synthetic system requires hot water at a higher temperature, generally above 90 degrees ； This temperature is considered too high for distillation systems, as it can easily lead to coking in the reboiler. It is recommended to implement a high-temperature difference circulation for the distillation system, with a separate setup (there is no need to use high-temperature corrosion and scale inhibitors, which can reduce costs).
We are using one. The treated hot water can be used for distillation