How to feed more than 100 tons of polypropylene powder into a product receiving bin 80 meters high through temporary piping?
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In order to conduct a single-unit trial run of the mixer in the newly built polypropylene plant, we purchased 700 tons of polypropylene powder, firstly to create a seed bed and secondly to test the granulation system. The problem now is that in order to test the granulation system, we have to transport more than 100 tons of powder to the product receiving tank located over 80 meters above the ground. Using conveyor chains requires a lot of labor and time; therefore, people have thought of utilizing the existing product conveyor line and adding temporary piping to transport the powder in a dilute phase. The issue here is related to the safety aspects of air transportation, the risk of dust explosions, and determining what size of fans are needed to carry out this transportation task. The pipeline used for transportation is 10 inches in diameter; please offer some suggestions. I have expressed my thanks here.
I don’t have any experience in this area, but I think the air volume should be determined based on the particle size of the material. Dust explosions are definitely a serious problem
This issue should have been considered at the initial stage of device design; thinking about it now makes things a bit confusing. I used to work at a PVC factory where thin-phase conveying was used. Later, the factory introduced technological innovations and adopted dense-phase conveying, which proved to be effective. For the main conveying pipes, stainless steel pipes with a diameter of DN 100 were used; those with a diameter of DN 350 tended to get clogged easily. For dense-phase transportation, it might be worth considering having the manufacturer prepare a plan.
I think it’s possible to use dilute-phase transportation with nitrogen as the transport medium. However, it’s essential to control the feeding rate carefully; a rotary feeding valve can be used to regulate this rate and ensure uniform feeding, thereby preventing too fast feeding from causing excessive pressure at the fan outlet and leading to shutdown. As for what kind of fan to choose, I’m not quite sure.
For lean-phase transfer, rotary blowers are generally used, but since you mentioned using nitrogen, the cost is too high; usually, air is used instead. As for dust explosions, I encountered the same problem in the packaging and transportation workshop at a PCV factory before, but the company didn’t really address it. It’s not a major problem; it’s a low-probability event. Just ensure that the usual safety measures are followed.
1. What manufacturing process is your device based on? Loop process or gas phase? Let’s talk about this first and then I’ll give you a solution. 2. How is the powder produced by polypropylene production transported to the intermediate bin in front of the mixer? Isn’t there a powder conveying system? 3, Wouldn’t it be good to use the existing powder conveying system? First, you should debug the powder conveying system first; once it’s debugged, won’t the conveying work properly?
For new installations, it is necessary to conduct individual tests on the granulation system in advance; however, the polymerization system does not yet meet the conditions for such tests. Therefore, we considered using the discharge pipeline of the polymerization system to transport materials to the product purification chamber. This would require reconfiguring the piping. The fans available are capable of generating a pressure of 10 kgf/cm2, and the height of the transmission pipelines is approximately 80 meters. Air is used for transportation rather than nitrogen. The concerns related to this approach are dust explosions and the transportation capacity.
So we thought of using the discharge pipeline of the polymerization system to transport the material to the product purification chamber; this would require re-piping. Isn’t the powder transportation system of the polymerization system still unfinished? Why is re-piping necessary? This should be taken into account in the test drive plan, right? Use air to transport dust? Are you trying to die? Haven’t heard of any accidents involving silo explosions, have you? As for the issue of conveying capacity, it is the responsibility of the patent holders and design institutes to ensure that the design of the powder conveying system can meet the required standards. So there’s no need for you to worry.
The feeding tank is designed as a nitrogen-sealed tank; nitrogen is used for feeding, and just as in catalyst feeding in continuous reforming, a lift fan is employed to recycle the nitrogen. Over 100 tons of polypropylene powder are fed into the product receiving tank, which is 80 meters high, through temporary piping.
The original process featured a delivery line for continuous addition directly into the powder drying tank; nitrogen could only be used as the medium, and if the drying tank was not available, temporary piping could be used instead.
Feeding is carried out through a feeding hopper, and the fan delivers the material to the top of the silo; if air is used for transportation, the risk of flash explosion is very high.