In the pharmaceutical and chemical industry, if the length-to-diameter ratio of the explosion venting system in Class A workshops exceeds a certain value, does that necessarily mean it fails to meet the requirements?
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As the title suggests: I’m seeking advice. In the field of pharmaceutical and chemical manufacturing, if the length-to-diameter ratio for explosion venting in a Class A workshop is too high, does that necessarily mean that the required explosion venting area will not be sufficient? The factory building has 4 floors; the heights of the first, second, third, and fourth floors are approximately 6 m, 5.5 m, 5.5 m, and 5.5 m respectively, while the width of the building is 20 m. Assuming the explosion venting area meets the requirements, what is the maximum possible length of such a workshop? Please include calculations related to explosion venting. The value of C is set at 0.110. Similarly, if I want to build a single-story Class A workshop that is 20 m wide and as long as possible, what would be its maximum length and height? I’m not good at Chinese, so I’m not sure if I expressed myself clearly. I hope those who are more skilled can give me some advice!
Guys~ Experts, please don’t give up on me
This post was last edited by 2005011lcj on 2019-10-29 at 16:58. Below is the calculation of the pressure relief area for your reference.
For a 20M wide Class A building, it’s difficult to determine the relevant values if explosion relief is only provided through the sides rather than via the roof; therefore, the fourth floor can serve as only one fire compartment. With many hollow floor slabs in between, it makes sense to use the roof for explosion relief. Fire compartments with a first-class fire resistance rating can cover an area of up to 3000 m2, so the maximum value would be 3000/4/20 = 37.5. For a single layer, if you use the roof for explosion venting, it’s fine even if the length-to-diameter ratio is high; calculating it as 2 sections will definitely suffice.
It doesn’t matter at all. There are plenty of Class A factories with three or four floors; why can’t the pressure relief area be calculated? If the length-to-diameter ratio is greater than 3, it’s divided into 3 sections, and each section is calculated separately. What’s the problem with that?
What was said on the 5th floor makes sense. To add further clarification: if the length-diameter ratio is greater than 3, it should be divided into several parts with a length-diameter ratio of 3 or less for calculation, and the division surfaces are not considered as part of the blast venting area； Furthermore, due to certain peculiarities of the chemical industry, there are still many cases where multi-story buildings of Class A are required for process reasons; in such cases, it is sufficient to ensure that the area of each fire compartment does not exceed the limits specified by building codes. This detailed explanation can be found in the illustrations of the «Code for Fire Protection Design of Buildings» (18J811-1), along with some examples and diagrams that make it easier to understand.
Chemical engineering calculation APP. https://bbs.hcbbs.com/thread-2693876-1-1.html The function for calculating the pressure relief area has not been released yet.
So it was the original creator after all; my apologies