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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
Why demineralized water is corrosive?
To remove the minerals from raw water, the raw water has to undergo several process during which energy has to be input to it. As a general rule, any substance with higher than normal energy level tries to come to a stabilized state by releasing the excess energy (compare with the electrons imparted with higher energy level, which try to return to lowest possible state for stabilization, or something having high potential energy due to elevation which tries to return to the minimum possible elevation to attain a stable state or to make it simple, remember: HE THAT IS DOWN, NEEDS FEAR NO FALL!). That is the reason which makes demineralized water highly unstable and reactive. It tries to react with metals to lose energy and stabilize.
the air will be in liquid state when its pressure is increased and its temparature is decreased.
eg: CNG is highly compressible gas.
Does any absorption take place in the stomach?
No. The stomach does not absorb anything.
The above answer is wrong. The stomach is responsible for absorption of alcohol in particular, as well as a fair quantity of the drug aspirin. The majority of aspirin is absorbed in the duodenum of the small intestines, but some is taken in by the stomach.
What is the difference between saturated steam and Superheated steam?
Saturated steam occurs when steam and water are in equilibrium. If you have a closed container of water and heat it, above 100 celsius the steam pressure will start to rise, and as the temperature continues to rise, the pressure will go on rising. What is happening is that steam is being evolved to match the temperature (steam tables will give this relation) and the steam conditions are said to be saturated because if the pressure is raised by external means, some of the steam will start to condense back to water.
If the steam pressure is held at a lower level than that achieved at saturation, by taking steam off to feed a turbine or other steam usage, there is effectively an excess temperature for that pressure, and the steam is said to be superheated. It in fact then becomes dry, and behaves as a gas. The amount of superheat can be quantified as so many degrees of superheat (celsius or fahrenheit).
Turbine designers want steam to be superheated before reaching the turbine, to avoid condensation causing blade erosion, and steam producing boilers in power plants are designed to produce superheated steam. In plants where no turbines are used, only satured steam is normally generated.
In heating applications, saturated steam is preferable, because it has a better energy exchange capacity. Superheated steam must cool down, and become saturated steam, before condensing in a heat exchanger. Also, superheated steam is a thermal insulator, like air.
That is why it is necessary to direct superheated steam through a desuperheater before using the steam in heating applications.
How do you collect crude oil out the ground?
It has to be pumped. A drill is used to drill down to the oil and then a pump is setup to get the oil out.
A packed fractional distillation column will be more effective at separating two closely boiling liquids than an empty one because you have more surfaces for condensation and revaporization of the liquid. A packed fractional distillation column has many more surfaces two allow the mixture of vapors to condense and distill again over and over to effectively separate.
How do you convert Reid Vapor Pressure to True Vapor Pressure and vice versa?
http://www.epa.gov/ttn/chief/ap42/ch07/final/c07s01.pdf page 56
How viscosity of mud effect the drilling?
importance of mud in our life is that mud is very useful for us it can be used in many ways .when mud falls on the face of a child the child looks more beatuful,also when it is on flowers.mud is real good thing .
What is plastic buckets made from?
Many buckets are made out of high-density polyethylene. HDPE is a durable, non-reactive thermoplastic that resists have an effect on and inhospitable climates all through transit or storage. In the blow molding process, uncooked HDPE resin, which in the establishing of the molding technique is referred to as stock, is loaded into a hopper.
What is difference between block flow diagram and process flow diagram?
BFDs provide a complete overview of the whole process in block diagram form. They summarise the major unit operation between process block units. PFDs characterize all the process flows to and from all the equipment required to perform the process within the boundaries set by the BFD
What is stroke length of a pump?
The stroke length of a pump is the distance it travels up before it travels down. The distance traveling up takes in air or water depending on the type of pump. The down pressure expels the air or water.
In a packed or tray column where you have vapor flowing up and liquid flowing down, there is an upper limit to how fast the liquid can drain downwards. The point at which liquid cannot flow down as fast as it is coming into the column is the "flooding point". The actual flooding point is partly dependent on how fast the liquid can flow down with no vapor flowing upwards and the rate at which vapor is trying to flow upwards. Cross sections of the column occupied by vapor are not available for liquid flow - effectively reducing the cross-section for downward flow of the liquid. You also get entrainment of liquid in the upward flowing vapor and drag on the liquid as it fights the direction of the vapor flow - the vapor wants to go up while the liquid wants to go down. This additional drag also slows down the flow of liquid trying to drain downward in the column. There is an analogous condition for two-phase liquid/liquid extraction columns.
What is the difference between clarifier and classifier?
Clarifier removes solids from Liquid and Clarifier removes solids from Gas
Why there are boiling range not boiling point?
I am not sure but may be it is because none of the substances have a fixed boiling point. The substance starts changing its state from liquid to gas before the mentioned boiling point .
For example Boiling point of H2O is 100.but it change it changes its state before it.Therefore there are boiling range not boiling point.
What is a petrochemical engineer?
A Petroleum Engineer is basically someone with a chemical engineering degree who works in refineries.
What countries does Canada export copper to?
for 2013, it was China,
for 2012, it was China,
for 2011, it was Finland,
& for 2010, it was China.
Why is heat trasnfer coefficient of saturated steam is higher than superheated steam?
when steam is at its saturation point for a given pressure, any heat removed will cause liquid water to form. So when saturated steam is used to heat something else, the heated object/substance receives the condensation heat of the steam. The latent heat of condensation/evaporation is 970 But/lb @ 0 psig. On the other, superheated steam only gives up about 10 BTU/lb if it is cooled 20 degrees F. That means that much more steam would be used to transfer the equivalent amount of heat. The liquid water interface also improves the heat transfer.
An Alloy is two metals mixed together.
it is the combination of one or more elements, usually metals. the mixture of elements in an alloy gives it new properties that are different from the properties of the individual element. it often eliminates disadvantages of the pure metal .
How much do mechanical engineers get paid yearly?
How much does anyone get paid? It varies a great deal depending on experience and the nature of the industry. Also, you need to look at the average hours worked per week and the nature of the job
In the U.K newly graduated Engineers can expect on average a starting salary of £18,000.
According to the web page below, Mechanical Engineer at an average of £35,623/annum is the 52nd best paid profession in the UK. (Taken from a survey of over 300 jobs)
http://www.thisismoney.co.uk/news/article.html?in_article_id=411942&in_page_id=2
