浸出器正压的原因与应对措施

Causes and countermeasures of positive pressure in extractor

浸出工厂出于安全、成本、环保等方面的考虑浸出车间都是负压生产，但有时由于生产操作控制不当或设备故障会导致车间短暂甚至长期处于正压状态，更多发生在车间大幅提产时蒸发量没有及时跟进调整就会导致浸出器出现正压，从而使车间暴露在不安全的状态下。

For the sake of safety, cost and environmental protection, and the other reasons, the extraction workshops are all under negative pressure production, but sometimes due to improper production operation control or equipment failures, the workshop will be under positive pressure for a short time or even for a long time, and more often occur in the workshop to increase production significantly. If the evaporation rate is not adjusted in time, it will cause positive pressure in the extractor, which exposes the workshop to an unsafe state.

浸出器正压的原因主要来自DT正压，DT正压的原因为DT的二次蒸汽不能被蒸发系统完全利用，而利用DT二次蒸汽量的大小主要取决于混合油的流量和混合油的浓度。

The reason for the positive pressure of the extractor mainly comes from the positive pressure of DT. The reason for the positive pressure of DT is that the secondary steam of DT cannot be fully utilized by the evaporation system, and the amount of secondary steam used by DT mainly depends on the flow rate of the mixed oil and the mixed oil.

DT二次蒸汽不能被蒸发系统完全利用的情况主要出现在浸出器转速提高。浸出器转速提高后，进入DT的豆粕流量增加，为了控制DT内气相温度和豆粕的残溶就会增加直接汽用量。此时蒸发系统内的蒸发量如果还没有升起来，DT排出的混合气体不能完全被蒸发系统吸收，就会造成DT的正压，甚至由于豆粕在DT内的脱溶时间减少，造成豆粕残溶超标，带来严重的安全隐患。有时工厂操作人员往往为了缓解这种情况通过提高尾气风机的转速增加尾气排出量，但因冷凝系统冷却能力有限，尾气系统吸收能力有限，尾气中溶剂气体没有被冷凝和吸收而被排到大气中，会造成排出的尾气中溶剂严重超标，溶剂损耗量增大，因此并不是解决问题的根本方法。

The situation that the DT secondary steam cannot be fully utilized by the evaporation system mainly occurs when the speed of the extractor increases. After the speed of the extractor is increased, the flow rate of soybean meal entering DT increases. In order to control the gas phase temperature in DT and the residual dissolution of soybean meal, the amount of direct steam will be increased. At this time, if the evaporation in the evaporation system has not risen, the mixed gas discharged by DT cannot be completely absorbed by the evaporation system, which will cause a positive pressure of DT, and even reduce the desolvation time of soybean meal in DT, resulting in residual soybean meal. Exceeding the standard brings serious safety risks. Sometimes factory operators often increase the exhaust gas discharge by increasing the speed of the exhaust fan in order to alleviate this situation. However, due to the limited cooling capacity of the condensing system and the limited absorption capacity of the exhaust system, the solvent gas in the exhaust is not condensed and absorbed and is discharged into the atmosphere, which will cause the solvent in the exhaust gas to exceed the standard seriously and increase the solvent loss, so it is not the fundamental method to solve the problem.

浸出器转速提高*主要出现在压榨量发生变化特别是预处理提高产量时，因进入浸出器的入浸料增多，使浸出器料位增加，浸出器转速就会加快。因此在大幅度提产时应先增大溶剂周转量，再提高物料的流量。一般提产时应提前20分钟左右，浸出车间按预处理大豆的增量参照溶剂比增大新鲜溶剂量，因为新鲜溶剂从溶剂工作罐（SWS）到浸出器混合油斗需要的时间比物料从轧坯机到浸出器的时间要长。这段时间混合油浓度会比较低，可以降低蒸发系统的蒸发量来进行调整。待膨化料进入浸出器时转速提高，相应DT直接汽用量增大，再对应调大混合油蒸发量，保证对DT产生的二次蒸汽的有效利用，防止浸出系统出现正压。在增加产量时切不可一次增加太多，应在浸出跑稳后慢慢增加。待浸出稳定后，调整轧坯机，很快入浸料就会增加。因此不可急于一下增加过多，如果一下增加太多，浸出器转速太快，使DT下料过快，脱溶时间短，会引起豆粕残溶超标，DT、浸出器正压的产生，产生严重的安全隐患。

The increase in the speed of the extractor mainly occurs when the squeezing volume changes, especially when the output is increased by the pretreatment. Due to the increase of the leaching material entering the extractor, the material level of the extractor increases, and the speed of the extractor will increase. Therefore, the solvent turnover should be increased first, and then the material flow should be increased when the production is increased substantially. Generally, the production increase should be about 20 minutes ahead of time. The extraction workshop will increase the amount of fresh solvent according to the increase of pretreated soybeans with reference to the solvent ratio, because the time required for the fresh solvent from the solvent working tank (SWS) to the mixing oil hopper of the extractor is longer than that of the material. The time from the rolling mill to the extractor is long. During this period of time, the mixed oil concentration will be relatively low, which can be adjusted by reducing the evaporation of the evaporation system. When the puffed material enters the extractor, the speed will increase, and the direct steam consumption of DT will increase accordingly, and then increase the evaporation of the mixed oil correspondingly to ensure the effective use of the secondary steam generated by DT and prevent positive pressure in the leaching system. When increasing the output, it must not be increased too much at one time, and should be increased slowly after the leaching is stable. After the leaching is stable, adjust the rolling mill, and the leaching material will increase soon. Therefore, do not rush to increase too much. If you increase too much at once, the speed of the extractor is too fast, so that the DT is cut too fast and the desolvation time is short, which will cause the soybean meal to exceed the standard, and the positive pressure of DT and the extractor will be generated, and may bring serious hidden danger.