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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
What is the order of efficiency of venturi meter orifice meter and rotoameter?
- The orifice plate can easily be changed to accomodate widely different flow rates, whereas the throat diameter of a venturi is fixed, so that its range of flow rates is circumscribed by the practical limits of Dp.
- The orifice meter has a large permanent loss of pressure because of the presence of eddies on the downstream side of the orifice-plate; the shape of the venturi meter prevents the formation OS these eddies and greatly reduces the permanent loss.
- The orifice is cheap and easy to install. The venturi meter is expensive, as it must be carefully proportioned and fabricated. A home made orifice is often entirely satisfactory, whereas a venturi meter is practically always purchased from an instrument dealer.
- On the other hand, the head lost in the orifice for the same conditions as in the venturi is many times greater. The power lost is proportionally greater, and, when an orifice is inserted in a line carrying fluid continuously over long periods of time, the cost of the power may be out of all proportion to the saving in first cost. Orifices are therefore best used for testing purposes or other cases where the power lost is not a factor, as in steam lines.
- However, in spite of considerations of power loss, orifices are widely used, partly because of their greater flexibility, because installing a new orifice plate with a different opening is a simpler matter. The venturi meter can not be so altered. Venturi meters are used only for permanent installations.
- It should be noted that for a given pipe diameter and a given diameter of orifice opening or venturi throat, the reading of the venturi meter for a given velocity is to the reading of the orifice as (0.61/0.98)2, or 1:2.58.(i.e. orifice meter will show higher manometer reading for a given velocity than venturi meter).
How coring of alloys during solidification be prevented?
By proper composition of metal & by slow cooling & by uniform distribution of metal
GAS ABSORPTION: The process of wholly taking in one substance into other through the pores or interstices is called gas absorption. EXAMPLE:When hydrogen chloride gas is passed through water it gets absorped to form hydrochloric acid ans by m.fahim
Is potassium aurocyanide used as an electrolyte in electroplating of gold?
A common electrolyte bath will normally contain either a potassium-cyanide solution or a cyanide-free solution based on sulfites or chlorides.
Is tin a pure substance or a mixture?
Pure Tin is a metallic element with the symbol Sn.
Tin is always pure. Tin is not a mixture, but it may be a part of a mixture, like in bronze
What is the melting point of petrol and diesel?
These data depends strongly on the chemical composition.
For gasoline: the freezing point is from -40 0C to -60 0C
For Diesel fuel: the freezing point is from -6 0C to -20 0C
Why is the glass transition temperature of polystyrene greater than of polypropylene?
Higher the glass transition temperature of the polystyrene can be attributed to the fact that sterically rigid bulky aromatic moieties like benzene in the styrene compared to that of aliphatic polypropylene
How does alloying help to reduce corrosion?
Corrosion is a chemical reaction that weakens a metal. It is a redox reaction, to be exact. By creating an alloy, new atoms (or different rations of atoms) are added in the metal being made, which changes the structure of the metal. This can form stronger bonds, which can be resistant to the redox corrosion reaction.
Note: Alloys can be made that have a worse resistance to such reactions, but there is no market for them, so they are not sold.
How does an Endoscope workWhat is it made of?
An endoscope is a type of medical equipment used in hospitals to look into other peoples bodies before they have an operation. It is made out of fibre optics and so would also make it easier in an hospital for emergency calls because you use the fibre optic stuff in phone calls.
(by the way i am only 13 and if anything is wrong please correct it)
Correction
I am a second year veterinary nursing student and I was searching for information on endoscopes for a report I'm having to write and thought this was a rather cute answer.
Just thought I'd post up what I found elsewhere and I hope it helps you :)
Fibre optics are small pieces of glass that have the ability to transmit light. They are ideal for use in an endoscope as they can act as both a light source and a camera. They are also small and flexible, meaning that an endoscope can be guided inside the body easily and without causing the patient any pain.
Surgical instruments can also be passed down the tube of an endoscope, such as a tiny blade, which can be used to remove tissue during a biopsy. Pulses of heat and electricity can also be sent down the endoscope, which can be used to destroy unwanted tissue or growths, such as small tumours or gallstones.
Here's the link http://www.nhs.UK/Conditions/Endoscopy/Pages/How-does-it-work.aspx
Naptha is a common name for the industrial solvent Petroleum Ether. Other names include benzine, X-4, or Lingroin. Chemically, naptha is a mixture of straight chained hydrocarbon-ethers, straight chained alkanes, as well as some aromatic hydrocarbons. The actual composition of the naptha will depend on its boiling point (indicative of the distillation temperature). Naphtha is a product of crude oil distillation in an atmospheric distillation unit. The refineries often produce a light naphta blend and a heavier naphtha which is can be used as a gasoline additive. Naptha is also extremely effective at solvating non-polar compounds and is used frequently in organic chemistry.
What are the symbols of chemical engineering equipment?
See in http://engstandards.lanl.gov/index.html and http://en.wikipedia.org/wiki/Process_flow_diagram
What is grain boundary scattering?
Grain boundary scattering refers to the magnetism that copper holds. By using grain boundary scattering, copper is more resistant to a magnetic pull.
Do you mean Evaporation? If so Evaporation is the Opposite of Percipitation ( the falling of rain ) so Evaporation is water rising into the atmosphere and becoming rain clouds which is then moving in the Water Cycle to the next point which is Percipitation.
The balanced equation for the reaction involved is as follows: C10H12O2 + Br2 + H2O ---> C10H13O3Br + HBr. Some C10H12O2Br2 will form as well.
Basically, corrosion is a disintegration of a material. Corrosion is typically associated with rusting, but that is only one type of corrosion. Other types of corrosion include, erosion, cavitation, fretting, galvanic, thermo-galvanic, intergranular, pitting, and more. The main causes boil down to a few root causes, chemical reactions, friction and a lack of durability.
Rust is a chemical reaction, there are more types of reactions than from water and air. Reactions from other metals, acids, etc. cause corrosion as well. Friction can cause stress cracking, fretting, and intergranular corrosion and erosion. Two pieces of metal that rub on each other can cause fretting and lead to corrosion. Or water running over a rock for a few hundred years can turn it into a smooth pebble. Durability is key. Some substances are harder than others, and thus harder to disintegrate.
Automotive Solutions:
powder coating and plating are common methods to prevent corrosion. Electroless nickel plating is common within parts like ABS sensor rings and gears. powder coating is used on pumps and tanks. zinc plating is often used on bolts and braces.
Below is a link to a study on corrosion, its costs, causes and how to prevent it.
What is the Cost of pneumatic control valve product?
Pneumatic process control valves are used in process industries to control the flow of fluid by using pneumatic actuators.
It requires 4.5 to 6 Kg/sq. cm of pressure to operate the valve.
Control room sends electrical signals of 4-20 ma to field where I/P converter converts these electrical signals into pneumatic signals.
Actuators use these signals to operate the valve.
Actuators moves the stem up and down depending upon input signals and control the valve opening.
4ma- 0% opening
8ma- 25% opening
12ma- 50% opening
16ma- 75% opening
20ma- 100% opening
What is differences between cooling tower and heat exchanger?
Cooling towers are also known as an air conditioner's radiator unit. A mist cooling system are fans that have water dripping in front of them in boxed units. These are still used in some parts of the developing world in the absence of air conditioners.
Glass can occur both naturally and synthetically. Examples of natural glass can be found in igneous rocks and asteroid impacts. Also, it is more gender neutral to say "human made" or "synthetic," rather than "man made."
How many types of thermosetting plastics are there?
There are Multiple:
Bakelite-which is used for cameras, rods, tubes… this plastic isn't often used.
Epoxy- which is used for surfboards and other things that need to stand extreme forces.
Melamine resin- this can make plates and other non-microwaveable kitchen utensils.
Polyimide- this plastic is known for thermal stability, good chemical resistance, excellent mechanical properties. It is normally orange/yellow colour.
Urea-formaldehyde- it is high tensile strength, flexural modulus and heat distortion temperature, low water absorption, mould, high surface hardness, elongation at break, and volume resistance.
Diallyl Iso Phthalate / Diallyl Ortho Phthalate:
These compounds are easy to mold and have no out gassing. They can be molded in compression, transfer, or injection equipment.
Cosmic DAP compounds are non-corrosive to inserts and resistant to weathering, fungus, and most solvents.
Fully cured parts manufactured from Cosmic DAP possess unsurpassed dimensional stability, even under load. They withstand solder temperature and will not creep after curing. That is why this state of the art material is used extensively in the space program, the connector and the electronics industries.
Offered in a variety of colors and flows, Cosmic DAPs do not require cold storage and have an average shelf life of one year at 23 ° C.
Cosmic Epoxy compounds are specially made to suit each customer's requirements.These materials possess outstanding electrical, mechanical, and thermal properties, and are available in the following grades:
Electrical Grades
The Electrical Grades offer superior electrical properties, dimensional stability, and mechanical strength. They are widely used in underwater connectors and other electrical insulation applications.
Electronic Encapsulation Grades
The Electronic Encapsulation Grades offer excellent adhesion to substrates good thermal shock and moisture resistance. These materials are predominantly used in passive devices such as resistors, resistor networks, inductors, capacitors, coils, switches, bushings, and relays. Supplied in a wide range of flows, they can be either injection, transfer, or compression molded. They flow easily at low pressure and have no out gassing.
Structural Grades
The Structural Grades offer high mechanical strength for use in aircraft structures and other applications to replace heavy metal parts. They can be either compression or transfer molded.
EMI Shielding and Conductive Grade
EMI Shielding and Conductive Grades offer a variety of shielding strengths for fabrication of core rods and to encapsulate surface mount and axial leaded inductors. This single molded compound eliminates the labor intensive over and under molding.
Farboset Molding CompoundsFarboset molding compounds are anhydride and novolac grade epoxy thermoset compounds formulated to provide superior electrical and moisture resistance properties.
Farboset Powder CoatingsFarboset powder coatings are nonanhydride dielectric grade epoxy powder coating is formulated to provide superior electrical and moisture resistance properties.
Alkyds are polyester based thermosets.These materials offer good electrical insulation, dimensional stability, and mechanical strength and are used in circuit breakers, relays, switches, coil bobbins, terminal boards, and connectors.
What does chemical engineering do?
They translate processes developed in the lab into practical applications for the production of products such as plastics, medicines, detergents, and fuels; design plants to maximize productivity and minimize costs; and evaluate plant operations for performance and product quality.
What chemicals are used in the modern soap making industry?
Same way it always was: fat and lye.
However a lot of "soaps" these days contain no soap, they are detergents.
It's just steel that has gone through the process of Parkerizing.
What is a geographical preference?
This is where one prefers to be employed; the location where one wants to commute to at the start of the workday.
For example, if you live in Pottstown, and you wish to be employed at a car dealership chain that is established in Pottstown, Limerick, and Hatboro, the likely candidate to indicate would be Pottstown. However, you may have an "in" with a manager at Limerick, so would not mind the longer commute, and would therefore indicate Limerick as your preference.
