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Chemical Engineering
Chemical Engineering is the branch of engineering that deals with the technology of large-scale chemical production and the manufacture of products through chemical processes. Today, the field of chemical engineering is a diverse one, covering areas from biotechnology and nanotechnology to mineral processing.
1,464 Questions
How long will a 50 gallon barrel of gasoline stay good for?
Untreated gasoline starts to go bad after 30 days. Treat it with a fuel stabilizer and theoretically it will last one year. If you keep it that long I would mix the treated gas with 50% fresh gas when you use it. That 50/50 mix will be ok to use. Untreated gasoline over 60 days old mix with 80% fresh fuel before using.
When is cryogenic process considered adiabatic?
A process can be considered to be adiabatic if heat loss/transfer is zero, or negligible compared to the system.
If the system contains for example, 1 x 10^6 J of heat energy and 3J are lost in a process, the process can be considered adiabatic.
The ports of the angle valve ( Inlet and outlet) are oriented at an angle 90 deg.
it i simply a projectile motion
assuming the vertical component zero
apply the equation
y=(1/2) (g) (t2 )
y=height
g=9.8
if we did not assume the data is in suffcient to calculate the time
What is the space velocity and space time in tubular flow reactor?
Space velocity is the number of reactors treated in unit time while space time is the time required to treat a reactor.
What is the difference between Standard cubic meter per hour and Normal cubic meter per hour?
A cubic meter is a cubic meter and that is world standard. There are no non-normal cubic meters or normal cubic meters.
Scroll down to related links and look at "Conversions of volume and capacity units".
Only for gases with ideal gas behavior there is made a theoretical difference between standard cubic meters and normal cubic meters.
Everything is in formula:
p*V/T = pn*Vn/Tn
where
pn = Pressure at normal conditions (1.0133x105 Pa = 1.0133 bar)
Vn = Volume at normal conditions (Nm3)
Tn= Temperature at normal conditions (273°K)
p = Application pressure
V = Volume at application pressure
T = Application temperature
This is valid only for ideal gases and gases with ideal gas behavior.
Another answer:
Be careful when you see standard (Sm3/hr) or Normal (Nm3/hr) for the following reason:
There is a variety of alternative definitions for the standard reference conditions of temperature and pressure. STP, NTP and other definitions should therefore be used with care. It is always important to know the reference temperature and reference pressure for the actual definition used.
TYPICALLY (BUT NOT ALWAYS):
STP - Standard Temperature and Pressure - is defined by IUPAC (International Union of Pure and Applied Chemistry) as air at 0oC (273.15 K, 32 oF) and 105 pascals (1 Pa = 10-6 N/mm2 = 10-5 bar = 0.1020 kp/m2 = 1.02x10-4 m H2O = 9.869x10-6 ATM = 1.45x10-4 psi (lbf/in2)) -->Note that the earlier IUAPC definition of STP to 273.15 K and 1 ATM (1.01325 105 Pa) is discontinued.
HOWEVER, Standard can also mean, in the US system of units, as air at 60 oF (520 oR) and 14.696 psia (15.6oC, 1 ATM).
SO BE CAREFUL - standard means one thing in Europe and quite another thing in the US, which is why you need a temperature and pressure when someone says
standard.
Typically, Normal conditions means the following temperature and pressure:
Pressure = 1 ATM = 0.0 psig, and T = 25C = 298K
However, I have also seen Normal refer to the following (from http://www.engineeringtoolbox.com/stp-standard-ntp-normal-air-d_772.HTML):
NTP is commonly used as a standard condition for testing and documentation of fan capacities:
- NTP - Normal Temperature and Pressure - is defined as air at 20oC (293.15 K, 68oF) and 1 ATM ( 101.325 kN/m2, 101.325 kPa, 14.7 psia, 0 psig, 29.92 in Hg, 760 torr). Density 1.204 kg/m3 (0.075 pounds per cubic foot)
If you have the temperature and pressure at standard, you can convert to normal conditions using the ideal gas law:
(PV/T)2=(PV/T)1
How siphon breaker works in the big closed tanks?
A siphon breaker works in big closed tanks by transferring fluid to an upper level coming into a tank from above. The purpose of the siphon breaker is to produce pressure at its outlet and the fluid weight to produce pressure.
How many Types of sensors and their explanation?
There are many types of sensors. They are used to measure and/or detect a huge variety of conditions including: temperature, pressure, level, humidity, speed, motion, distance, light or the presence/absence of an object and many other types. There are many versions of each type which may use a different sensing principle or may be designed to operate within different ranges. Sensors in some cases react to the environment in which they are placed and this reaction is used to measure the property being sensed. For example, a common temperature detector is known as an RTD (resistance temperature detector) and this contains a platinum wire. The electrical resistance of the wire changes with temperature so how the resistance changes can be used to measure the temperature. Many sensors use this type of principle where the variation of an electrical property of a sensing element is a measure of a property being sensed. Other types of sensors emit a signal and either measure how the area reacts to the emission or measure the reflection of the signal bouncing off an object in front. Inductive proximity sensors are one of the commonest sensors in use today. They emit a small electromagnetic field and use this to sense the properties of the area in front of the sensor. So they can detect a metal object in front and can be used to check if a machine is in the required part of a cycle or if a door is closed. Magnetic, capacitive and many other sensor use this type of principle. Some sensors send out a light signal and measure if it is reflected back. These are called photoelectric sensors and come in a multitude of varieties. Some directly detect a reflected signal (Direct detection mode), some check if a beam being reflected from a reflector is interrupted (retroflective mode) and others send a beam to another sensor receiver and detect an interruption of the beam (Opposed mode sensor). Other sensor such as radar and ultrasonic sensors operate also by detecting the reflected signal from the object being detected. Everyone is familiar with the police radar guns that detect the speed of a vehicle, the way a bat can "see" using reflected signals and the wonder of the pictures of unborn babies that can be produced from reflected ultrasonic signals.
Why saturated steam is used in exchangers frequently rather then superheated?
The heat transfer coefficient of superheated steam is poor. Saturated steam has a better heat transfer coefficient, and also most of the heat transferred from steam occurs because of the condensation phase change.
What are the difference between bill of quantity and bill of materials?
Bill of materials (BOM) is a list of the raw materials, sub-assemblies, intermediate assemblies, sub-components, components, parts and the quantities of each needed to manufacture a final product.
Bill of quantities (BOQ) is a document used in tendering in the construction industry in which materials, parts, and labor and their costs are itemized.
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What is searle's bar method for thermal conductivity?
http://www.pems.adfa.edu.au/~s9471553/level1/Teaching/LabScripts/Thermal_09.pdf
What is polished water does it mean ultra-high pure water?
polished water is the water in which silica is removed and it is of high purity water.all the contaminants are removed including silica
The category that acrylic falls into is polymethalmethacrylates (plastics derived from petroleum by-products).
What is the difference between path function and state function?
state function did not depend on the path , it depends on the initial and final point of the system where as path function depends on the path of the reaction.
