Interview Questions.

Question 1. What Is Ammonia (r717 / Nh3)?

Answer :

Ammonia is a commonplace, clearly occurring compound within the surroundings. It can be naturally damaged down into one atom of nitrogen and three atoms of hydrogen, its chemical formulation consequently being NH3. Ammonia is a key intermediary within the nitrogen cycle for vegetation and animals, for the reason that the environment includes nearly eighty% nitrogen. It is crucial for lots biological strategies.

In reality, ammonia is most of the most abundant gasses inside the environment. Used as a refrigerant, the colorless fuel consists of the designation R717 / R-717. Given its abundance in nature, ammonia is known as a “herbal refrigerant”.

Question 2. What Are The Main Advantages Of Ammonia As A Refrigerant?

Answer :

Ammonia is one of the most weather-friendly and value-efficient refrigerants to heat cool and freeze. It is also:

Non-ozone depleting: Ozone Depletion Potential = zero
Non-weather adverse: Global Warming Potential = 0
Abundant: a part of natural cycles, vital for many organic strategies
Safe: with right managing
Energy-green: usually higher power efficiency than systems the use of chemical gases
Cost-green: low refrigerant buy fee, low machine strolling fees
Readily available: global
Chemical Interview Questions
Question three. How Is Ammonia Used As A Refrigerant?

Answer :

Traditionally, refrigerant-grade ammonia has been used as a 99.98% natural substance, freed from water and different impurities. It is effortlessly available, less expensive, and capable of soaking up huge quantities of heat while it evaporates. Lately, new blends incorporating ammonia had been proven to provide extra advantages in terms of lower discharge outlet temperature, a decrease compression ratio, and a higher refrigeration capacity. Blends encompass the hydrocarbons propane (R290), octafluoropropane (R218), octafluorocyclobutane (RC318), or isobutane (R600a). The blend R723 - which include 60% ammonia and forty% dimethyl ether - promises similarly capability in excessive temperature warmth pumps.

Question four. Is Ammonia Safe?

Answer :

Yes, with right managing. In any mechanical refrigeration system, leaks will arise. This reality is exacerbated while the leaks involve odorless refrigerants risky to human fitness, or otherwise dangerous for the environment. 

Having been used as a refrigerant for more than one hundred fifty years, ammonia has an extended safety document. The inherent protection of ammonia comes from its feature odour, which signals even the smallest leak, at concentrations some distance decrease than any dangerous stage. Moreover, its density and really confined variety of flammability, advances in protection mechanisms and system designs (plate heat exchangers, separate sealed cubicles, leak detection systems, electric switching outside the booths and many others.), well-educated people operating with R717 systems, in addition to industry codes and standards have made positive that ammonia poses hardly any chance to human fitness. 

As an instance, america Chemical Safety Board (CSB) reviews that R717 incidents led to simplest 4 fatalities within the ten-12 months duration from 1994 to 2004. This compares with over 800 deaths from lightning moves within the USA at some stage in the same length.

Question 5. Is Ammonia Flammable?

Answer :

Ammonia is difficult to ignite and famous a slim range of flammability. It is flammable most effective at excessive concentrations and below extraordinarily confined situations. Because ammonia will now not sustain a flame on its very own, ignition of ammonia vapour requires an uninterrupted outside flame supply. Ammonia burning velocity, at a most of eight cm/s, is considerably decrease than different flammable refrigerants, and isn't high enough to create an explosion. Properly designed ammonia refrigeration systems which are well ventilated and freed from open flames or ignition resources are secure towards capability explosion.

BioChemistry Interview Questions
Question 6. Is Ammonia Toxic?

Answer :

Yes. Ammonia contains a B2 safety category, which means that it may be toxic for humans at excessive concentrations. However, as even the slightest traces of ammonia can be detected inside the air, a safe and on the spot restore of a gadget leak is possible. Moreover, the easily detectable and penetrating odour will inspire people to leave the instantaneous place of launch before any harmful awareness will occur. The safety record of ammonia refrigeration is likewise due to the reality that ammonia is 1.7 instances lighter than air and as a result without difficulty vented with the aid of mechanical means into the surroundings. If a leak happens in a refrigeration device under strain, simplest the pressurized fuel and, absent additional warmness, a smaller amount of the liquid in that area could be launched. 

The statistics: The human body can manage ammonia in small quantities. Any quantity within the atmosphere below 20 parts consistent with million (ppm) is seemed as no longer risky. Already at amounts of up to 53 ppm, ammonia’s function odour might be great. At amounts of three hundred-400ppm, prolonged publicity will become unpleasant, and best in quantities over 700ppm it can begin affecting human health. As a end result, the prevalence of fatality and extreme damage in R717 structures is extraordinarily low.

Question 7. Does Ammonia Have An Impact On The Ozone Layer?

Answer :

No. With an ozone depletion potential of 0, ammonia does now not damage the atmospheric ozone layer in any experience.

Analytical Chemistry Interview Questions
Question 8. Does Ammonia Contribute To Global Warming?

Answer :

No. Ammonia has a Global Warming Potential (GWP) of zero, meaning it doesn’t add to the greenhouse effect related to global warming. In reality, ammonia, one of the most not unusual compounds located in nature, is vital to the earth’s nitrogen cycle and its launch within the ecosystem is immediately recycled. The use of ammonia as a refrigerant is therefore steady with global agreements on lowering global warming and ozone depletion.

Question 9. How Does An R717 System Reduce Greenhouse Gas Emissions?

Answer :

To verify the entire environmental performance of refrigerants and their systems, each Direct and Indirect Emissions should be taken into consideration:

Firstly, using ammonia reduces the direct greenhouse gasoline (GHG) emissions. This is due to its Global Warming Potential (GWP) of zero, as compared to a GWP of one,700 for R22 and 3,260 for R404a, and even better values for different chemical refrigerants. Why is that this important? As an instance, from a standard business refrigeration device 10-25% of the full refrigerant charge is emitted to the atmosphere every yr. Assuming that leakage rates are the identical, ammonia will consequently spare the planet tones of greenhouse gases compared to another chemical refrigerant currently used. In addition, leakage costs for ammonia are considerably decrease than for some other refrigerant as the gasoline is detected lots earlier because of its function odour. 

Secondly, ammonia also results in decrease Indirect GHG emissions through maximizing energy performance of equipments in which they're used. This is due to a mixture of things, together with its favorable thermodynamic traits. As a result, ammonia structures use less primary strength to provide a certain refrigeration impact as compared to different usually used refrigerants. Its indirect international warming effect is consequently one of the lowest of all refrigerants.

Quality Control Chemist Interview Questions
Question 10. Where Does The Ammonia Used As A Refrigerant Come From?

Answer :

Presently, there are an expected  billion metric heaps of ammonia present inside the international. Of this quantity, approximately five percentage is guy-made. Approximately 18 million metric lots of ammonia are produced yearly in North America by myself, and of this quantity, much less than two percent is used for refrigeration.

Question 11. Is Ammonia A Totally New Refrigerant?

Answer :

No. Ammonia was first used as a refrigerant in the 1850s in France and became applied in the United States within the 1860s for synthetic ice production. The first patents for ammonia refrigeration machines have been filed inside the 1870s. From all the refrigerants used in food processing, ice rinks, chillers and different applications, most effective ammonia has secured a lasting function as a refrigerant.

Even while halocarbons have become the refrigerants of choice, ammonia remained the maximum used refrigerant for commercial applications in many nations. Because of ammonia’s proven applicability as a secure and efficient refrigerant for over a hundred and fifty years, it's miles at once available for wider usage and new packages. Today, ammonia stays the maximum normally used refrigerant in huge systems to method and keep food and beverages.

Chemical Engineering Interview Questions
Question 12. How Energy-efficient Is Ammonia?

Answer :

Ammonia is able to absorbing large amounts of heat when it evaporates. For commercial refrigeration, ammonia is normally widespread as the maximum efficient and price effective refrigerant available. This, in turn, brings critical advantages to customers, because the decrease running costs make a contribution to lower food charges. 

For chillers, ammonia also can offer most efficient performance. As an instance, the important ammonia chilling plant of London Heathrow’s new Terminal 5 makes use of four chillers, each with a cooling capability of 6.6 mW, or 1,875 tones. The massive-scale R717 chillers reduce power intake through at the least 30% as compared to smaller neighborhood chillers. Moreover, storing the chilled water reduces the gadget ability and takes gain of night time energy prices.

Chemical Interview Questions
Question thirteen. In Which Applications Is Ammonia Used?

Answer :

Ammonia is appropriate for the following applications:

Food processing, Cold garage & Delivery: Ammonia refrigeration is the backbone of the food enterprise for freezing and garage of each frozen and unfrozen foods in many components of the arena (which include fruits, veggies, meat, fowl, fish, dairy, ice cream, drinks). In the variety 50 kW to 2 hundred kW ammonia can be used, and for larger freezers ammonia is almost usually desired because of improved strength efficiency and decreased leakage.
Petrochemical & Pharmaceutical enterprise, Mining: For a few years, ammonia has been the refrigerant of desire in big industrial refrigeration applications, inclusive of technique cooling, bloodless storage, the manufacturing of ice to be used in chemical reactions, and mining. Ice plants are normally far larger than the ones located within the food enterprise.
Air Conditioning: Ammonia is increasingly used for air con in public buildings, hospitals, colleges and workplace parks, as well as to decorate the efficiency of strength generation facilities. Ammonia refrigeration has also been used to provide aircon for the International Space Station and the subject matter park Biosphere II, in the USA. 
Chillers: Chillers the usage of R717 and a secondary warmth switch fluid (intrinsic to chillers) are to be had within the ability variety from 2 hundred to 2000 kW with a few larger fashions. They permit for the safe use of ammonia in huge buildings. Ammonia may be used in absorption chillers – with water because the absorbent –, in screw chillers, or in reciprocating chillers. The new Terminal 5 of Heathrow, one of the global’s biggest airports, is using a important ammonia chilling plant to provide all heating and cooling. 
Supermarkets: More lately, ammonia has been used in conjunction with a secondary refrigerant including carbon dioxide in a ‘cascade’ gadget, meaning that much less ammonia is needed to reap first-class results, and that the ammonia fee may be contained in a plant room or different safe surroundings. 
Marine refrigeration / Fishing vessels: R717 has been an increasing number of used in marine refrigeration device. Applications include its use for reefer ships, as proposed refrigerant for sorption ice machines, and for fishing vessels each as unmarried refrigerant in addition to in combination with CO2 (R744), especially for low temperature uses.
Heat pumps: Absorption warmness pumps for hot water space heating are basically gas-fired and typically provide cooling simultaneously with heating. An up to date circle of relatives of absorption machines is available the usage of an ammonia-water cycle powered through natural gasoline. R717 has also been used in medium-length and big capacity warmness pumps. In addition, development has been made within the discipline of using ammonia for residential warmth pumps, with preliminary prototypes with an output of 6 kW having reportedly worked reliably with ammonia expenses of much less than 100g.
Leisure industry, Ice Rinks, Ski Slopes: Ammonia may be used for refrigeration purposes in ice rinks and ski Slopes, and in parallel, for the heating of leisure facility premises.. Europe’s largest outdoor stadium with an ice rink (Karlstad, Sweden), and the sector’s third biggest indoor snow park (Dubai, Emirates) are both the usage of R717 to continuously produce ice and snow.
Question 14. How Much Ammonia Is Needed For Different Applications?

Answer :

Large ammonia refrigeration systems include up to 60,000 kg of refrigerant. Installations for meals processing and industrial plant refrigeration typically variety from 5 to 100 tonnes. Around the sector large R717 systems are situation to increasingly more stringent protection policies and stress is being located on businesses to lessen the size of ammonia refrigerant fees. Therefore, proprietors of big business plant life are beginning to use ammonia along side a secondary refrigerant consisting of carbon dioxide (R744) or potassium acetate, which means that an as much as ninety% reduced ammonia rate is needed in comparison to an ammonia-best gadget. The discount of charge does no longer result in any overall performance compromises.

Question 15. Is Ammonia Compatible With All Components & Materials?

Answer :

Ammonia is well matched with many, but no longer all substances suitable to synthetic refrigerants. As an instance, it is best compatible with a few generally used refrigeration system lubricants, except for polyol ester (POE) and poly vinyl ether (PVE) lubricants, and it has most effective limited packages with poly alkylene glycol (PAG) lubricants.

To accommodate for the protection requirements in an R717 machine, a few changes to an present machine design might be needed to combine safety features and ensure compatibility. Ammonia isn't like minded with maximum forms of electrical wiring insulation. Metals of creation interior ammonia systems usually are restricted to carbon and chrome steel, but excellent compatibility of ammonia with copper and copper alloys in systems with careful moisture control have been stated, supplied that there's no presence of water leading to copper corrosion. Aluminium is well suited with ammonia, but it is touchy to corrosion in water circuits because of the presence of chlorides.

Organic Chemistry Interview Questions
Question 16. Are There Any Legal Requirements When Using Ammonia?

Answer :

The use of ammonia is situation to a wide variety of technical and protection standards in different global areas, which, while thoroughly observed, make sure the refrigerant safe and distinctly green use. Workers managing ammonia installations ought to be informed of emergency methods and applicable requirements.

In addition, regulations require normal inspection of protection gadget and ongoing education to put together people inside the event of an emergency, which, compared to other risks in society, are especially rare. While enterprise-pushed codes and requirements encompass certain device engineering and layout standards and working codes, federal regulations prescribe place of business safety rules when the usage of ammonia, environmental requirements (which include reporting and hazard control duties), and transportation rules.

These requirements create regulatory burdens for ammonia refrigeration programs, as facilities ought to comply with Process Safety Management (PSM) and Risk Management (RMP) Programs connected to office work and document retention. 

Ammonia systems designed at some stage in the beyond 20-30 years in accordance with strain vessel rules and limitations on the quantity of ammonia used, are very high high-quality with superb standards of protection. For older structures, powerful training of employees with operational obligations is worthwile as the best low-value preventive measure.

Question 17. What Are The Key Markets For Ammonia Today?

Answer :

Industrial Refrigeration: Today, ammonia remains the maximum fee-powerful and strength-green alternative for all varieties of commercial gadget. In fact, R717 makes up 15% of the full refrigerant marketplace. R717 is expected to remain the favored preference for big installations once ozone-depleting materials might be dominated out under worldwide agreements. In the USA and Canada ammonia is properly regulated and enjoys a extensive-spread use.

In Europe, R717 has been extensively followed for industrial refrigeration inside the UK and Germany but is more tightly regulated in France, Belgium, the Netherlands and Italy, and it's far therefore less common. It is the maximum common alternative to HFCs for large structures in Scandinavia, especially because of regulations and taxation on greenhouse gases.

First installations in Australia have proved the performance of R717 plants. As a most current instance, ammonia freezes 6000 head of lamb every day in one of Australia’s biggest meat processing corporations, being capable of freezing 1610 bulk packed export meat cartons with a 24-hour turn round. 

Commercial Refrigeration: The use of ammonia in cascade grocery store refrigeration systems is developing, particularly in international locations with stringent barriers on the usage of HCFCs and HFCs, along with Scandinavia. 
Chillers: Although the usage of R717 continues to be constrained, this marketplace is anticipated to grow. As a most current instance, a vital ammonia chilling plant offers continuous deliver of warm and chilled water for heating and air con to Terminal 5 of London’s airport Heathrow.
Heat pumps: R717 has been carried out in medium-length and big capability warmness pumps, especially in Scandinavia, Germany, Switzerland, and the Netherlands.
Polymer Chemistry Interview Questions
Question 18. What Are Major Barriers For A Widespread Use Of Ammonia?

Answer :

From a basically financial evaluation, ammonia ought to find broader packages as a refrigerant than it currently enjoys. However, to recognize ammonia’s complete potential as a refrigerant, protection rules and technical standards round the arena can be required to end up more tailored to ammonia refrigeration systems and steady across global markets.

Regulatory regulations and a loss of clean encouragement from coverage makers to transport closer to herbal refrigerants currently obstruct a wider spread of R717. To sum up, a deficit of promotion, a lack of technical and regulatory harmonization, lacking steerage for operators, and a patchwork of countrywide protection regulations pose immoderate administrative and monetary burden on the ammonia enterprise. Politicians’ popularity of ammonia as a sustainable opportunity to ozone-depleting and high worldwide warming materials below global environmental packages may want to raise those boundaries. To attain this intention, information on the overall performance and use of R717 needs to be updated and unfold in coverage to allow for an informed desire.

BioChemistry Interview Questions
Question 19. What Is The Process Of Including Heat Exchanges In Ammonia Refrigeration System?

Answer :

The warmness exchangers are utilized in ammonia refrigeration system from a totally long time. The warmth exchanger used is having smaller sizes and they may be equal to the tubular exchanger can. This method works fine for flooded gadget that require a separate liquid from the vapor. The gadget that is explained consists of a vessel, a drum, and accumulator and header tank with the warmth exchanger. It works like this: >Liquid ammonia actions from vessel to exchanger >Vapor is again to center of drum >Vapor is eliminated from the drum and liquid enters through exchanger because it has decrease density than others getting into at the equal rate inside the machine.

Question 20. For A Given Bulk Solid How Can The Particle Size Distribution Be Determined?

Answer :

In order to decide the particle length distribution the simplest approach is to make use of a sieve stack. In this approach a stack is created of with exceptional mesh sizes at every stack level. The shape is such that the biggest mesh size is at the top and the smallest at the bottom. Once this setup is created the earlier than beginning the burden and other values of the strong is noted down. Once that is performed the strong is positioned at the topmost cylinder and the complete setup is exposed to a combination of vertical and horizontal moves. This will make the solid bypass via exclusive mesh sizes inside the method separating the one-of-a-kind debris consistent with their sizes. There are different extra advanced strategies of determining the particle size distribution as properly which includes video imaging and laser diffraction as properly.

Geochemistry Interview Questions
Question 21. In A Crusher Where Is The Energy Provided To It Is Used Up For?

Answer :

The power fed to a crusher is utilized for the subsequent functions:

To produce the elastic deformation of the particles previous to the fracture of the debris.
In order to provide inelastic deformation this causes the debris to reduce in length.
The electricity is likewise used to purpose the equipments elastic distortion.
In the friction of the particles between themselves and among the system.
The electricity also gets used up within the shape of heat, noise and vibration in the plant.
The energy also receives used up inside the friction losses in the plant. Most of the energy is misplaced and only a few of it's miles nicely applied. Nowadays it's miles of top importance to reduce the energy losses.
Question 22. In Case Of Welded Vessels Why Is Stress Relieving In The Form Of Post-weld Treatment Necessary?

Answer :

When a steel is welded collectively the point at which the two surfaces are joined are subjected to very excessive temperatures. During this term the metals can undergo lots of random metallurgical approaches. This reasons the metallic to be tougher and brittle. This relies upon on the quantity of carbon content. In order to relieve the metallic of those residences warmth treatment is accomplished at the affected regions. By doing so the affected regions ductility will increase. In this system the heat is maintained in the affected steel in line with the thickness of the metallic. The temperature of the heat is calculated from the P wide variety which is particular for a selected composition.

Question 23. Mention Some Of The Specialized Grinding And Crushing Methods?

Answer :

Some of the in particular developed grinding and crushing methods are as follows:

Electro hydraulic crushing: In this approach an underwater discharge is comprised of a high capability capacitor.
Ultrasonic Grinding: This type of grinding the material id positioned between a pressure roll and plate both of which are ultrasonically activated. This system is used for grinding micro sized substances.
Cryogenic grinding: For sure materials powerful grinding isn't viable through traditional means which include rubber, textiles and so on. In order to address this trouble the fabric is frozen to extremely low temperatures the use of liquid nitrogen. Once the cloth is frozen it's far grounded as according to requirements.
Explosive Shattering: This kind of shattering remains on experimental foundation, it involves power to be transmitted to the particles within the shape of shockwaves from an explosion chamber.
Chemistry Interview Questions
Question 24. On What Basis Are Materials To Be Crushed Evaluated Apart From Size?

Answer :

The desire of the crusher machine to be hired to crush the substances relies upon on the following homes apart from the size of it:

Hardness: The hardness influences the electricity intake and the sporting of the device. With difficult materials it's far necessary to apply a low speed system along side stress lubrication.
Structure: Normal granular substances may be beaten by way of the usage of compression and effect methods. On the other hand for fiber like substances compression and impact strategies do not work rather a tearing action is required.
Moisture content: The moisture content material in the materials can substantially have an effect on the choice of machines. In case of extra moisture the substances flow receives hindered and it's miles critical to save you them from caking together and shape balls.
Crushing Strength: The quantity of power that is required to overwhelm a cloth can be derived directly from the crushing power of the fabric.
Friability: This assets shows the tendency of a cloth to fracture.
Stickiness: As the name shows this property is used to evaluate how sticky a material is as a totally high sticky cloth can clog the equipment.
Analytical Chemistry Interview Questions
Question 25. What Are The Advantages Of Using A Ball Mill Over Other Conventional Methods Of Crushing?

Answer :

The benefits of using a ball mill over other traditional techniques are as follows:

The mill may be used in multiple modes. It may be utilized in each moist and dry modes. The wet mode allows in the elimination of the product.
The set up fee and the electricity consumption of the mill is low.
Since the mill can be utilized in an inert surroundings therefore it would be used for the crushing of explosive materials.
It can be used for any kind of hardness substances and also the grinding medium is reasonably-priced.
It can also be used for continuous and batch operations.
The ball mill supports two varieties of grinding:

Open circuit grinding.
Closed circuit grinding.
Question 26. What Are The Assumptions Made For Kynch Theory?

Answer :

The following assumptions are made for the Kynch Theory:

Across the horizontal layer the particle awareness is uniform.
The consequences of the wall may be neglected.
No differential settings of particles are considered because of shape, size or composition changes or differences.
The pace at which particles fall relies upon simplest on the local concentration of the particles and not anything else. 
The concentration is taken into consideration to be uniform at some stage in or it is able to be assumed to boom toward the bottom.
The velocity of sedimentation tactics 0 because the awareness reaches the limiting value.
This limiting cost corresponds to the sediment layer at the bottom which receives deposited.
Chemical response Interview Questions
Question 27. What Are The Assumptions Made On Conservation Equation?

Answer :

The conservation equation is implemented to the assets of the gadget.

It will have complicated in addition to clean to solve calculations:

Closed system: That doesn't have flows out of the substance. It deals with the closed mass float.

The equation to calculate that is:

Accumulation= Generation > Open system: that lets in the substance to go into or leave the machine.

Conserved country gadget: in which no generation of the quantities happens. The quantities in this doesn't get created or destroyed. These quantities are useful to balance consistent with the users need.

Steady State machine: wherein no accumulation of the substance is in regular state. This device avoids having differential equations. The procedure needs to be demonstrated before it can run in any nation.

Quality Control Chemist Interview Questions
Question 28. What Are The Criteria Involved In Choosing Mass Balances For Components?

Answer :

The mass balances are used to mix all the hundreds that are gift within the substance and create an usual effect while it's far combined with other elements. The equations can be set for the factor to allow any of the components used in mass balances.

The criterias on which the balances are dependent are as follows:

Need to discover which issue(s) are concerned in fixing the equations, without proper records the equation can`t be solved.
Find out approximately the additives about which the affordable assumptions may be made. By doing this the procedure receives simplified and it's going to help in making short calculations.
Question 29. What Are The Design Considerations For A Piping System For The Transfer Of Slurries?

Answer :

The following factors need to be considered for designing a piping machine to hold slurries:

The design of the piping gadget ought to be able to self drain.
At the sections of the pipe wherein self draining is not possible provision to install manual draining must be mounted.
At sure factors where the chances of plugging are excessive, rod-out or blow-out connections ought to be provided to clear the traces.
In order to make flushing possible smooth-out connections have to be established on both side of the primary valves.
For smooth get right of entry to all the manifolds must have flanged connections.
T-connections are a must for get entry to flanges.
Electrochemistry Corrosion Interview Questions
Question 30. What Are The Different Characteristics That Can Affect The Flow Of Bulk Solids And How?

Answer :

The foremost characteristics which could affect the waft of bulk solids are as follows:

Moisture Content: when the moisture content material is excessive the majority solids become sticky in nature. This moisture can every now and then be absorbed from the environment by using some solids.
Temperature: The float of the bulk solids may be on occasion laid low with the temperature and also the period for which it's far uncovered to a specific temperature.
Particle size: More cohesive debris are typically located in bulk solids which are finer. Round debris are handled without difficulty in contrast to unusual, asymmetrical shapes.
Time at relaxation: Many times the drift of positive bulk solids is tormented by the time for which it has been kept stagnant or at relaxation. The greater it's far kept at relaxation the extra slow the majority strong flows.
Question 31. What Are The Different Types Of Equipment For The Conveyance Of Solids?

Answer :

The various sorts of equipments to be had for the conveyance of solids are as follows:

Gravity Chutes: This system is based on gravity for the solids to fall below.
Air Slides: In this gadget the particles are suspended in air, and go with the flow at an angle to the horizontal.
Belt Conveyors: This equipments use a belt to switch the solids.
Screw Conveyors: The solids are moved the use of a rotating helical impeller.
Bucket elevators: The solids are moved using buckets which are attached to a belt in motion.
Vibrating Conveyors: The solid debris are subjected to vibrations and journey over to a table in a chain of steps.
Pneumatic/ Hydraulic Installations: The particles are transported over a circulation of air or water.
Question 32. What Is The Different Ways In Which Solids Can Be Blended?

Answer :

There are diverse methods wherein solids can be blended, some of the not unusual methods are:

Convective mixing: In this form of blending the group of particles of a strong is transferred from one region to another, lively repositioning takes place on this method. This kind of mixing is prevalent inside the Trough mixer.
Diffusion blending: In this type of mixing a brand new interface is fashioned over which the particles of a stable are dispensed. A desirable instance of diffusion blending is within the traditional barrel mixer, where a brand new interface is formed.
Shear Mixing: In this kind of blending slipping planes are created over which the group of particles of a strong are mixed.
Question 33. What Are The Factors Involved In Considering The Choice Of Dry Screw Compressor?

Answer :

Screw compressors are made from a pair of meshing helical screws that is used to compress the gases. The dry screw compressors are used to have a go with the flow range of 85-one hundred seventy m/h and the discharge strain is of 2070-2760 kPa. The dry screw compressor consists of timing gears this is maintained aligned with the rotors. The effectiveness is dependent on the clearances that exist among the helical rotors and among the chambers used for sealing the compression cavities. They are compact and clean having the restrained vibration and require spring suspension as nicely.

Chemical Engineering Interview Questions
Question 34. What Are The Factors Involved In Designing Kettle Type Reboiler?

Answer :

To design the kettle type reboiler the requirements that needed to be gift are as follows:

The length of the kettle has to be decided.
Provide the gap to sluggish down the vapor pace of all the liquid droplets.
Deciding the vacation spot in which the vapor would be deposited.
Handling a distillation tower with the following property: huge space, excessive performance and high reflux fee.
The peak of the vapor space ought to be kept such that the variations within the temperature might not affect the kettle.
There have to be excessive warmth flux for the kettles that run on higher temperatures.
Question 35. What Are The Merits Of Using A Falling Film Evaporator?

Answer :

The advantages of the use of falling movie evaporators are as follows:

These forms of evaporators have very high warmness switch coefficients ranging from 2000-5000 W/m(square) for water and 500 to 1000 for natural beverages.
The residence instances are short in case of heated surfaces, 5-10 seconds without recirculation.
They have very low pressure drops, zero.2-zero.5 kN/m(rectangular).
These evaporators are well suitable for vacuum operations as properly.
The evaporation ratios are very excessive. 70 according to cent with out and 95 according to cent with recirculation.
They have a totally huge working variety, they can provide as much as 400% of the minimal throughput.
In addition to the above blessings they have a low value of operation and are less liable to fouling.
Question 36. What Are The Methods Involved To Test Helium Leak Testing In A Vacuum System?

Answer :

The helium receives detected while it is discovered inside the region of suction line. The helium source is surpassed over the flanges and possible resources of leakage in the vacuum device. The tracking of the system takes vicinity to look the detector and the pump suction to be found for the detectable quantity of helium. The pressure may be improved or reduced consistent with the environment. If the machine is permitting the strain and the vacuum at the same time then greater stress can be carried out to set the leaks. An installation of IR unit may be performed to suction the substance of the pump and the spraying might be done on the flanges.

Organic Chemistry Interview Questions
Question 37. What Are The Problems That Are Associated With The Expansion Joints?

Answer :

Expansion joints are said to be vulnerable factors which are used in piping. They are used to reduce the pressure that comes within the piping at the same time as installing and implementing it. This allows minor piping to be settled at some stage in the joining function. Expansion joints can't stand the stress that is being produced by means of the piping forces.

The troubles which have been given are as follows:

Expansion joints get dirty very without difficulty and they tend to build up because the time progresses.
They encompass a few vulnerable points that may`t stand the strain of the piping.
The troubles can be removed if the drains are installed well and purging of the material is being carried out.
Question 38. What Are The Reasons Of Removal Of Particles From Effluent Gas?

Answer :

The fundamental motives for the elimination of debris from effluent gas are:

In order to shield and maintain the health of the workers and operators inside the plant. It is also achieved to shield the encircling populace. The primary danger is due to the breathing in of the dust debris which could reason health problems.
It is likewise completed to limit the possibilities of explosions. Many carbonaceous substances remain suspended in air and when combined with finely powdered metals can form a surprisingly flamable aggregate.
Particles also are eliminated to reduce the loss of valuable substances.
It also can be used to recycle the fuel for ex in case of blast furnaces the gasoline is used to fire the stoves.
Question 39. What Are The Steps Required To Design A Vapor-liquid Separator Or Flash Drum?

Answer :

The steps that are required are as follows: 

The size of the vapor-liquid separator relies upon on the glide price of vapor and the liquid that is popping out of the vessel.
Assumed from the float rates that if they may be recognised then the dimensions can be determined out.
Use vertical strain vessel to set it up or set up it at given location.
The period to diameter ratio can be taken to offer liquid inventory between the level of liquid and the bottom of the vessel.
Provide a blockage mesh segment at the vapor outlet to permit the vapor pass through the mesh this is taken and may efficaciously go away the vessel.
Let liquid glide control the level of the valve.
Question 40. What Are The Steps Taken To Operate A Tank-blanketing Valve?

Answer :

The steps taken are as follows:

Tank blanketing valves provide a way to save you and control the fires in the flammable liquid storage tanks.
The vapors which are produced cannot be ignited if there may be no deliver of oxygen present at that time.
The oxygen in maximum of the instances being supplied by way of the air this is drawn into tank from the atmosphere whilst the empty method is taking area.
Install tank blanketing valves with inlet related to the inert fuel this is saved under the stress. And the tanks outlet is being placed in vapor area.
The stress drop is going on within the tank at predetermined level in which the blanketing valve lets in the switch of fuel into vapor space.
Polymer Chemistry Interview Questions
Question forty one. What Are The Strategies Acquired To Cure Tube Vibration And Exchangers In A Shell?

Answer :

The techniques that may be accompanied are as follows:

To remedy the tube vibration makes use of the tubes that doesn’t allow passing of the glide-caused vibrations through them and are longer in peak than others. Usually the tubes supported >Are of 3-four inch. To make the bundle stiff insert steel slats and rods among the tubes that is used inside the method.
Add a shell nozzle contrary of the inlet to reduce the drift of the velocity of the fluid in 1/2. This solution works for non-detachable bundles that may easily be solved additionally by means of including a distributor belt at the shell. This might be high priced way to adopt as it calls for greater man energy and use of extra tubes.
Question 42. What Do You Understand By Wet Bulb Globe Temperature?

Answer :

The moist bulb globe temperature index is used to degree the sultriness of the environment. The sultriness is calculated on the basis of the humidity impacts, the air velocity and temperature and also the solar`s radiant heating aspect. The sultriness in some instances might be deadly and subsequently it's far very essential to preserve this underneath consideration. The moist bulb globe temperature index quantity became advanced inside the 1950`s and is now normal as an industry general.

It is produced from 3 temperature readings:

Wet bulb temperature
Ordinary dry bulb temperature
Black bulb globe temperature
Geochemistry Interview Questions
Question forty three. What Is The Method Adopted To Minimize Shell Side Pressure Drop In A Shell?

Answer :

The method of defensive the shell from the strain drop could be very important as it is very vital level, in which if no longer taken care well the shell has to be replaced because of its degradation. In this rods or tube protectors are used instead of plates in pinnacle rows. The use of these rods puts much less stress drop and offers better distribution of the strain at the plate. The plate that is used causes an abrupt of 90 diploma flip of shell movement and a further stress drop on the complete shell. Use of the tube protectors will allow the shell to be stored from this and continues its longevity.

Question 44. What Is The Method Involved In Analyzing Powders For Composition?

Answer :

The technique that is used to research powders for compositions referred to as as Fourier transform-infrared spectroscopy. This method is broadly used to send the mild beams of various wavelength passing through the pattern this is given and the mild this is reflected from there might be analyzed by means of spectroscopy. This method is used to discover the absorption of each wavelength. The wavelength is measured with the laser light this is being referenced and on the premise of that calculations will be carried out. The technique is adopted to degree the compositions with accuracy.

Question 45. What Is The Procedure To Estimate The Friction Factor Involved In Heat Exchanger Tubes?

Answer :

The following method is worried in determining the factors used within the heat exchanger tubes which can be various with the temperatures.

These are as follows:

Determine the average of the temperature through taking the imply of all of the temperatures stored inside the processing line.
Check the circumstance of the fluid coming into the road at around three hundred Celsius and leaving at round 280 Celsius.
Determine the bodily houses at the temperature of 290 Celsius and the friction factors of the tubes at the same temperature.
Use the formulation to calculate the friction thing of the laminar glide inside the case wherein the liquid is cooling: Mean temperature/((sum of viscosity/wall viscosity)*0.38) Where Bulk and wall is determined at imply temperature over the period of line.

Use the formulation to calculate the friction thing of the turbulent waft in the case where the liquid is cooling:

(Mean temperature + bulk residences / ((sum of viscosity/wall viscosity)*zero.11))/ (bulk viscosity/wall viscosity)*0.17.

Question forty six. What Is The Process Of Including Heat Exchangers In Ammonia Refrigeration System?

Answer :

The heat exchangers are utilized in ammonia refrigeration device from a very long term. The warmth exchanger used is having smaller sizes and they may be equal to the tubular exchanger can. This manner works first-rate for flooded gadget that require a separate liquid from the vapor. The gadget this is defined includes a vessel, a drum, and accumulator and header tank with the heat exchanger.

It works like this:

Liquid ammonia actions from vessel to exchanger.
Vapor is again to center of drum.
Vapor is eliminated from the drum and liquid enters through exchanger as it has lower density than others coming into at the equal price within the system.
Question 47. What Is The Use Of Gear Pumps In Motor?

Answer :

Gear pumps makes use of meshing gears that permit the pump fluid to be displaced with the aid of the technique of displacement. They are used for hydraulic fluid strength applications. They are one of the key factors concerned in chemical installation having a sure viscosity to pump fluid. This kind of pumps uses tremendous displacement pump having high stress and coffee capacities. This includes the potential to handle huge variety of viscosities, and permit clean to build and preserve the pumps. The gear pumps are controlled through the motor speed. Gear pumps can’t cope with high tolerances and the fluids which can be freed from abrasives.

Question forty eight. What Significance The Angle Of Repose Holds In The Chemical Industry, Explain?

Answer :

The perspective of repose is a property of particulate solids. A conical pile is fashioned while a bulk strong is poured onto a flat surface. The attitude formed between the flat surface and the pile side is known as the attitude of repose.

The perspective of repose depends on the following elements:

Density of the fabric
Surface region
Coefficient of friction of the fabric A material having a low attitude of repose could constantly create float piles as compared to substances with a excessive angle of repose. This is used in the designing of equipments which are used for particulate solids. In addition to that this attitude may be used to calculate the size of the conveyor belt that is used to transfer the materials.

Question forty nine. Why Does Catalytic Converter Used In An Automobile?

Answer :

The catalytic converter is a device that converts dangerous compounds in harmless compounds.

The compounds dangerous in nature are as follows:

Hydrocarbons- that is in the shape of unburned fuel that creates pollutants and is greater dangerous.
Carbon monoxide is very harmful gas fashioned by using the combustion of gas and used in particular for fuels.
Nitrogen oxides is likewise one of the gases that is poisonous in nature and produced with the aid of the release of warmth from the engines. The launch of nitrogen from the engine gets combined with the oxygen within the air. The catalyst converter takes these dangerous gases and uses the catalyst this is lined at the ceramic honeycomb or beads and attached to the exhaust pipe. This converts the carbon monoxide in carbon dioxide and makes it smooth for the character to devour it. The hydrocarbon receives converted in carbon dioxide and water. Same manner the nitrogen oxides additionally gets transformed in nitrogen and oxygen.