How to eliminate vortices at the outlet of the equipment
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We have a reactor in which vortices tend to form near the end of the discharge process, when the material is almost completely emptied. There are residual flammable and explosive gases inside the equipment; two flash explosions occurred at the beginning of last year, both times when the material was about to be completely discharged. Our analysis suggests that this phenomenon is related not only to the structure of the equipment itself and the properties of the residual gases (which are heavier than air and can explode easily due to high flow speeds), but also to the vortices formed as the material is discharged, which disrupt the airflow. Later, we changed the discharge method, introduced nitrogen gas during the dissolution and discharge processes after the reaction, and fixed the frequency of the motor driving the discharge pump at 25Hz. These measures proved effective. But I wonder: if it is indeed as we analyzed, are there any measures available in the device’s structure itself (such as the discharge valve or pipes) to prevent the formation of vortices? I remember that when I was looking at water injectors, it seemed to be said that the venturi tube had this function, but it couldn’t possibly be installed in that location. . . I hope everyone will discuss this. Last edited by Pseudo Xiaobao on 2009-3-28 20:29]
It seems that it would be better if the discharge pipeline had a greater slope or if there were a balance pipe, but these solutions are difficult to implement due to space constraints and the properties of the material (high viscosity). As a supplementary note: vortices cannot form in the material after reaction; they are mainly created when water is added just before the material runs out. In fact, the balance pipe is located on the floor below the equipment, and the discharge pump is also on that floor. Last edited by Pseudo Xiaobao on 2009-3-28 20:43.]
An anti-vortex plate can be welded at the outlet of the container to prevent vortices from forming as the liquid flows out. And it is advisable to install a low liquid level probe.
A liquid seal can be designed inside the reaction equipment to prevent organic gases from escaping. The liquid seal area can be cleaned using nitrogen purging. It is also possible to install one on the pipes. Last edited by Albertlu on 2009-3-29 07:51.]
We have encountered this issue as well; the simplest solution is to add a cross-shaped deflector, also known as a vortex breaker, and it works very well. When adopting this approach, it is also necessary to conduct several experiments depending on the size of the tank and the location of the discharge outlet, in order to determine the length and installation position of the cross-type spinner.
The tank in which we install the vortex breaker is the pre-tank for the hydrogenation material; this is to prevent air from being drawn into the hydrogenation reactor along with the vortex. Therefore, the tank is not completely emptied during each feeding process – 15% of the material remains to seal out air. However, since vortices form at a material level of 30%, the deflector we use is placed about 300 units away from the outlet; the material in question is sugar solution of type BX50, with moderate viscosity. If the material is to be discharged completely, then there is no need for a deflector. As for your situation, it’s not very clear; you can try it several more times to ensure the results.