Questions tagged [process-engineering]
Process engineering focuses on the design, operation, control, and optimization of chemical, physical, and biological processes.
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Pressure loss of for flushing sand filter with air
This is a cut-away view of a sand filter:
For flushing the filter, water and then air is pumped/blown under the filter. I'm interested in the pressure loss:
The lower bound for the required air ...
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Types of crushing
What are the different types of crushing (not crushers)?
I know there's impact crushing, I think there is also pressure crushing and absrasive/friction crushing. Basically, what I am looking for is an ...
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What is exactly dead-burnt lime, and why is less reactive than quicklime?
When producing lime on a lime kiln, there exists the possibility of overburning the original limestone and producing the so-called dead-burnt lime, with a much lower reactivity than quicklime.
Some ...
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How to transfer high pressure hydrogen using flexible pipes?
The task is to transfer hydrogen (high pressure gas > 400 bars) from offshore platform to land. To do so we have to use flexible pipes but for high pressure and high flow rate I'm afraid we can't ...
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How to transfer compressed gas GH2 from one tank to another at the same pressure?
The problem is to transfer all the compressed hydrogen from one tank on a ship at 400 bars to fill another tank on earth (also to fill it at 400 bars). What are the common technologies and equipment (...
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How to calculate the terminal velocity of grains in a pneumatic conveyor?
Here is the main question I got from a textbook:
Rice is transported by a pneumatic conveyor. The particle density is 1.4g/cm³. The major, intermediate and minor diameters are 1cm, 0.3cm and 0.4cm ...
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Proposing a Transfer Function from a Response Graph
I need to propose a transfer function from the following graph. The K value (or amplifier gain?) we were given is 2 and it has a step response of 2 as well. When looking at the graph though it looks ...
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What is the gain of a purely integrating process?
Consider a system where: $ \frac{Y(s)}{U(s)}=\frac{k}{s} $. Is the gain k, or infinity? Given that to a step response, steady state is never reached, but it increases linearly with no end. Thanks!
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How to determine which variables are state or input variables in dynamic modeling?
When given a P&ID and a process flow diagram, and asked to determine which of the relevant variables to a process input variables, and which are state variables (eg.: mass flow, temperature, ...
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What is the difference between mathematical and process/control degrees of freedom?
Taking mathematical DOF as:
$$ DOF= N_{vars}-N_{eqs} $$
How would process, or control degrees of freedom be defined as?
Thanks!
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How can I check boiler blowdown sample line compliance with international code such as velocity= 1.5 to 1.8 m/s and flow 1000 ml/min
looking to cross verify this blowdown sample line with below given data against International code
such as Velocity: 1.5 to 1.8 m/sec and flow 1000 ml/min.
Data available:
Location of sample line: ...
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Heat Transfer in a tubular reactor with constant jacket temperature - impossible solution?
I have received from my professor the following problem:
A first-order exothermic reaction A -> B takes place in a tubular reactor (typical PFR). The tube is cooled to a constant wall temperature $...
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Under what conditions is grinding unnecessary for liquid-solid leaching in mineral processing?
I am a chemical engineering student and I am having trouble understanding a passage in a separation process textbook I am reading. The passage is about the preparing solids for leaching, such as ...
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Method of separating oxygen from a mixture of oxygen + carbon monoxide
I have a 99,9% oxygen, with 0,1% is CO. Is it possible to separate the CO from oxygen in this mixture? The closer the percentage to 0 for CO, the better.
I've read about separation of oxygen from air, ...
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Calculating gas volume in a gas-liquid system/pressurized vessel
There is water in a tank and the tank is connected to a piece of piping that has a volume of 2.5L.
The headspace above the water is pressurised by using air, to a pressure of 3 bar (a).
What happens ...
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Relationship between the height of the filter cake and the applied solution
Situation
When a solid is applied to a suction filter for filtration, a cake is formed which is washed with the help of washing water. The filtrate flowing through contains the parts of the solids to ...
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How to mix pure CO2 with air so that a bioreactor can be fed with air at 0.1% to 10% CO2?
The situation is we have to prepare a gas mix of air and CO2 which has to be given as input from 0.1% to 10% CO2 of air mix to the aqueous medium in a bioreactor?
I'm trying to build a simple and ...
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What type of electrical machine component for counting time?
I am looking for the proper piece of hardware to do what I'm looking for on my current prototype machine build.
I want a timer to begin counting upwards in seconds when a switch is activated, and ...
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Process disturbance in PI controller help
This is the project i'm working on and i'm struggling to understand one sentence which is stopping me from progressing the project.
I'm struggling to understand what it means when it says to add +/- ...
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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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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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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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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 ...
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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 ...
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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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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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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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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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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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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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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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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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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’...
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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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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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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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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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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 ...
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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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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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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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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 ...
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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. ...
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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 $J_{CO_2}$ ...
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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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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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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 ...
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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 ...
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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 ...
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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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