Questions tagged [process-engineering]
Process engineering focuses on the design, operation, control, and optimization of chemical, physical, and biological processes.
72
questions
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What is the fouling effect (in rate, foulant thickness) of sand inside tube side of a shell and tube heat exchanger?
I am working with RO reject which has high turbidity (mainly insoluble salts and also sand now). This is also my process stream and needs to go through a heat exchanger at 50-60C and flowing at 0.25m/...
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1answer
45 views
Does P&ID have cross-reference same as electrical drawing?
In electrical i usually use cross-references to identify their symbols locations, I am still yet a lot to discover P&ID. So my question is, does P&ID have this such of thing?
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25 views
P&ID questions on reports, connection, etc
Good day to all of you. I got some questions in my mind regarding on P&ID:
In electrical, symbol will have their own default reference name for example "Motor" will use "M" , ...
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2answers
31 views
Gas Seal for slowly turning shaft
I am working on a small waste treatment project where there is a small mixing vessel (about 5 liters - more or less 20cm diameter). The mixing process produces methane gas which shouldn't escape the ...
0
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1answer
27 views
How to manage two control loops as safety when BPCS is shared?
I am trying to wrap my head around some excerpts from:
CCPS Layer of Protection Analysis
CCPS Guidelines for Independent Protection Layers and Initiating Events
IEC 61511
I am trying to understand ...
0
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1answer
46 views
Recommended books for process engineering? [closed]
I made a career change from machine design to CNG processing. What I’m looking for are some good books/handbooks that cover the following topics. Something similar to Machinery’s Handbook.
Piping, ...
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2answers
151 views
Identification a Symbol for P&ID's Standards
i have a question regarding on PID standards ISO 14617. Below is the attached symbol graphic, i seem cannot find anywhere what actually this symbol refer to from standards that i have looked up; PIP, ...
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2answers
22 views
Safety stock - how to determine how many multiples of the standard error measurement one should use?
I am trying to work out the best formula to use for calculating the safety stock to be used in Heijunka/production levelling.
According to this article, the best approach is to use the root mean ...
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1answer
44 views
Crossflow HX tube and fin, derive Tout hot side as a function of mdot hot side in
Apparatus:
Crossflow Tube and fin HX. (liquid-to-air Intercooler),
Hot Side: Tube side, gas flowing internally
Cold Side: fin side, water flowing in crossflow
Goal:
Generate an environment in "...
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0answers
26 views
Reading a value off a screen with a camera
I'm looking to log some information on a piece of equipment I have running at home. It displays the information I want - operating rpm and some other settings - on seven-segment displays. In an ideal ...
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0answers
14 views
What's the best type of steam Trap for Superheated Steam?
Process Engineering Newbie here.
What kind of Steam Traps are best suited for condensate removal in super-heated steam line or manifold?
The super-heated steam is to be supplied to a process reactor ...
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1answer
44 views
Thrust by turbo fan jet engine
How much thrust can I produce with a turbofan jet engine without injection of fuel and with just compression of air, which will be heated by convection if initial temperature of air of 20 oC and its ...
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0answers
17 views
Custom Models in Process Engineering
I'm using Aspen Custom Modeler to create a model to be used in Aspen Plus and Aspen Plus Dynamics, and I'm having trouble figuring out how to code the mass balance, energy balance, etc. I'm ...
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2answers
45 views
How to add a controlled amount of a nutrient solution to a water line
I have an existing water supply system for the cattle on my farm whereby 6 troughs located in different fields are all fed from a common header line.
The pressure in that line ranges from 3-5 bar (It’...
1
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2answers
42 views
Choosing Pressure Vessel head
Can I use a conical head at the bottom for a small diameter steam manifold ( Schedule 40- 3 inch dia. and 2 inch dia. ) that needs to operate at high temperature (~450 deg Celcius) and High design ...
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2answers
5k views
Block diagram vs flow chart?
I was studying a book on control systems where I read that a block diagram is a specialized high-level type of flow chart.
What is the difference between a normal flow chart and a block diagram?
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1answer
101 views
Solving a linear mass balance equation in the form of Ax = 0 with variables in vector x
I have been tasked with solving a series of linear equations in the form of Ax = b, where b is the zero vector. Specifically, I have a matrix E which is 4x7 and a column vector r which is 7x1, as ...
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1answer
52 views
How exactly do noise canceling headphones work?
I purchased a pair of noise canceling headphones today and I was just wondering how exactly they are able to cancel out background noise?
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1answer
243 views
Custom User Models in Aspen Plus
I'm trying to simulate a purifier in Aspen Plus in a cryogenic system. This purifier is just meant to change the pressure of the outlet stream based on the inlet flow and pressure (we are using the ...
1
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1answer
148 views
Modelling reactor jacket with or without insulation, how to proceed?
I am currently trying to derive a model to help estimate as precisely as possible how much time can be saved by insulating the jacket of a reactor used for eating and cooling.
EDIT: I edited my post ...
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0answers
48 views
When teaching separation processes, which one should be introduced first? Distillation or absorption?
I am preparing a basic course on Separation Processes (5th semester, BSc Chemical Engineering). I can see that many well-known textbooks (e.g. Seader & Henley, Wankat) start by teaching in detail ...
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1answer
27 views
Entrainers to distill MTBE from Methanol? - Chemical Engineering Question
What have you found to be some effective entrainers to distill MTBE from Methanol, given the azeotropic conditions at 67%. I have tried to simulate 1-butanol, as well as ethanol, and numerous other ...
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1answer
55 views
How to create a Liquid tight cable seal in a fuel storage tank
I am working on a telemetry system where a liquid level sensor (Hydrostatic pressure sensor) is used to monitor the volume of fuel (gasoline / diesel) in an underground storage tank.
The sensor has ...
3
votes
1answer
67 views
Designing a Chilled Process Water System for Small Plant
I am designing a new, closed loop,chilled water system for our small injection molding outfit and can use some help where to begin. Here are some of my knowns:
Northeast NJ, USA, no air conditioning. ...
4
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1answer
116 views
Modelling gas desorption from a still solution (e.g. a beer)
The common way to model or estimate gas (e.g. CO2) desorption rate from a liquid solution is by using an equation similar to this one
$J_{CO_2} = -k_L a(H·C^G_{CO_2} - C^L_{CO_2})$
where $J_{CO_2}$ ...
0
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1answer
37 views
If I replace a flow orifice with a Coriolis flow meter of the same size do I need to worry about pressure drop with the new Coriolis meter?
I have a 3 inch line with a 1.5 inch flow orifice. If I take out the flow orifice and put in a 1.5 inch coriolis meter will the pressure drop be the same or better with the new coriolis meter than ...
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2answers
771 views
Can Fortran 90 be used with Aspen Plus, or only Fortran 77?
I am attempting to write a user model in Fortran that can be connected to the Aspen Plus process simulator. Can Fortran 90 be used, or does Aspen only work with the older Fortran 77? I have checked ...
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3answers
115 views
How to find the balance position of valve downstream a tank?
We have a tank which has a constant inflow of water (Qi). The level (h) of water in tank is controlled by opening/ closing (l) a valve downstream of the tank. Overflow height of the tank is 4 meter. I ...
0
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1answer
50 views
How to identify the time delay of manipulated variables which are important to the final quality of polymer product
In a polymer production process, there are a lot of manipulated variables(MV) such as temperature ,pressure , or level of reactor that affect the quality of my polymer product.
However, it usually ...
6
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2answers
85 views
Does every engineering design needs to have a complete theoretical backing or may experimental data suffice?
This may sound rather vague on its own so I will explain with examples.
The solid booster rockets used by NASA space shuttle used a central bore design because it had a certain characteristic on ...
4
votes
1answer
94 views
Real world applications where one would use a force function in PLC programming?
I'm curious about which scenarios one would use a force function when using a PLC programming interface. Examples pertaining to process engineering, manufacturing, or industrial settings would be ...
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0answers
42 views
Industrial machinery and equipment [closed]
I am a mechanical engineer who is interested in learning different processes and equipment mainly used in process industry namely, textile, chemical, sugar mill, and other food process industry.
Is ...
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2answers
53 views
Is there any method to recycle air-pollution into fertilizer?
Vehicles and Factories produce air-pollution like Nitrogen Dioxide(NO2) and Sulfur Dioxide(SO2).
Plants use Fertilizer with those same compounds (NO2 & SO2)
So, by what method can air-pollution ...
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0answers
428 views
How to use VBA on Aspen Hysys? [closed]
I am trying to write a program on Aspen Hysys. Hysys has a script manager to write scripts using Visual Basics for Applications syntax. Having no background in VBA, I'd like some help to:
Import the ...
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1answer
226 views
How does an industrial engineer develop a process? [closed]
I would like to know what industrial engineers use for planning and developing a process:
What is the most widely business analysis modeling language used (Think ...
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2answers
225 views
Valve first,then heat exchanger OR heat exchanger first then valve
In my exam, I was given 2 options to design a process. Assuming a saturated liquid coming out from the separator, A) should the stream pass through a valve to reduce pressure, then to heat exchanger ...
0
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1answer
90 views
How do you get a closed vessel to >90,000 psi internal pressure
Im trying to build a cold isostatic press with a internal vessel area of 300mm3.
A cold isostatic press forms green metal components using pressures greater than 90,000 psi.
Using an oil or water/...
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1answer
110 views
Boiling Point, Pressure and Distillation
I have a line in my text that states the following:
"For systems with low boiling points (e.g. Ethane-Ethylene, propane-propylene etc.), high pressures are used so the vapour leaving the column at ...
3
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1answer
232 views
Chemical Engineering Process Analysis - Process Flow Calculations using linear matrices
I am doing a process flow question and trying to calculate the grams of $\text{C}_{10}\text{H}_{14}$, $\text{C}_4\text{H}_6\text{O}_3$, and $\text{C}_{12}\text{H}_{16}\text{O}$ produced during a ...
5
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2answers
294 views
What is the correct pipe size for a 2inch pipe?
I'm was looking into the ASME B16.5Pipe flanges and pipe fittings and it has 2 dimension tables metric and inches.
What I found was rather strange for me. I was ...
1
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1answer
84 views
How do you calculate the required power of a disk turbine (Rushton turbine) to rotate a fluid at a given speed?
I am designing a potato peeler which is practically a bucket that has a rotating disk (figure below) at the bottom driven by a motor. Water and potatoes are put inside the bucket and the disk rotates ...
4
votes
2answers
494 views
Can I control latent/sensible heat changes in a counter-flow, induced draft cooling tower using climate?
Some extensive background information to start
I'm attempting to reduce water consumption at 25+ production facilities, and I've identified that the largest consumption of water (60+%) comes from ...
7
votes
2answers
165 views
How to optimise feed-forward control of a process based on a prediction using the prediction confidence?
I'm looking for a control method for a production process with the following characteristics:
1 control variable
many process parameters (+-50)
1 resulting variable
continuous measurement of ...
0
votes
1answer
719 views
What is the gain and time constant of a system with a constant output?
For example, if your transfer function is defined as :
$$\frac{H(s)}{Q(s)} = \frac{1}{5s}$$
What would the gain and time constant be in this case (since it's usually in the form of $\dfrac{k}{Ts+1}$ ...
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0answers
43 views
Why have cascading vessels in the 'B' part of the 'AB' wastewater treatment process?
The AB process is wastewater treatment process that works like this:
'A Stage': Wastewater is (after mechanical treatment) subjected to a high load activated sludge process where also a lot of ...
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2answers
2k views
Derivation of Overall Mass Transfer Coefficient
The flux in the gas can be written as:
$$N_{1}=k_{p}(p_{1}-p_{1i})$$
And the flux in the liquid can be written as:
$$N_{1}=k_{x}(x_{1i}-x_{1})$$
And we know that $$x^*_{1}=\frac{p_{1}}{H}$$
How ...
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2answers
157 views
Second Order Transfer Function Question regarding Overshoot Formula
If I have a closed loop second order transfer function such as:
$$T(s) = \frac{10-s}{0.3s^2+3.1s+(1+24K_{c})}$$
Can I still use this formula for overshoot (when a step input is applied) ?:
$$\frac{A}...
5
votes
1answer
146 views
Working Out Shaft Torque in a Stirred Tank with a Cylindrical Cavern Formation (using a non Newtonian fluid)
Here is some background to the problem (in a stirred tank):
"With yield stress non-Newtonian (viscoplastic) fluids, it is possible to generate an agitated volume around the impeller, defined as a ...
0
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1answer
158 views
Mass Transfer from an Oxygen Bubble
I think there is an error in this questions solution and I want someone to check:
Example 8.1-4:Mass transfer from an oxygen bubble A bubble of oxygen originally 0.1 cm
in diameter is injected ...
3
votes
1answer
692 views
How do temperature and pressure influence the rate of evaporation of water in a closed vessel?
I am trying to solve a fairly simple question but I'm kind of stuck on the technicalities:
Imagine that water is evaporating into initially dry air in the closed
vessel shown schematically in Fig....
