Hello everyone, I was trying to find an example how to simulate a vacuum system in Aspen Plus. But, I could not find an article online. Could you please share your experience with me ..read more

Can anyone please tell me how do we size the gas line, when the gas line is having solid content?  ..read more

Hi all,   I heard one saying that when sizing flare size, the venting flow rate should be the sum of all PSVs in one fire zone.  Is this right? and where this requirement comes from ? API?  Attached Thumbnails ..read more

Hello,  I am a process engineer learning about the performance of centrifugal compressor. I came across this paper (attached) that explains how suction pressure can affect compressor performance. On Page 3, under the Heading "Compressor Inlet Flow" the paper says (emphasis mine): "Conversely, increasing compressor suction pressure will significantly increase gas density and reduce the gas volume. The lower the suction pressure the larger the effect of pressure changes on compressor capacity. For example, increasing pressure from 18.7 psia to 20.7 psia decreases the inlet gas flow rate by ..read more

How to begin solve this problem     A company has three plants that produce ethanol and four clients to whom the ethanol can be delivered. See the attachment Attached Files  Minimizing cost using solver.pdf   21.35KB   5 downloads ..read more

Vacuum column bottom (Vacuum residue) pump frequently getting low pressure issue. Suction strainer found normal, also temp, level and suction flow is also normal, even discharge pressure and flow is also normal but the suction pressure frequently getting low. Pump is motor driven and ampere found normal. What is a issue and how to overcome this problem ..read more

I want to calculate required cooling water utility temperature to condense acetic acid at 10 torr. I have boiling point of acetic acid at 760mmHg is 118degc and at 10 torr (-29degc).  How can we calculate the utility temp ..read more

Hello!,   I'm designing a shell and tubes heat exchanger for the recovery of 2210 thermal kW from hot flue gases, so i can heat production water for an ORC. Gas from 594.4 to 105 °C and water from 75 to 102°C. Heat transfer area required is just around 1.4m2 for this service, which i double checked just to be sure the result is correct. Does this result make any sense? I don't have any reference system on which i can verify if this heat exchanger is appropriate.   Thank you ..read more

Hello all, I hope you can help me out in a simple topic. I’m going to model a flue gas stack in aspen hysys to check heat transfer and I’m using pipe segments feature. The bottom of the stack is conic starting from diameter of 17’ and being reduced to 8’ in 70’ of height. After that stack is like a 8’ pipe. Any idea of how to include that conic section in pipe segment? Or any idea of an alternative way of modeling a stack? Thanks Maryam ..read more

During design development of underground vessel (mainly closed drain), two design approach is possible: Buried or NOT.  I could not find a universal design for this issue.  With buried vessel, some issue such as accumulation of toxic gas (in case of leakage) or fire issue can be resolved.  However, maintenance of buried vessel is difficult due to lack of sufficient visible access. Also, it is not possible to use external pump for buried vessel. External corrosion of buried vessel is another issue.  Let me know your recommendation and experiences.   ..read more