Hello readers.....!!
Today i gonna give you a description that limits upto my knowledge, and most of you may find it useful, about the Industrial Agitators, Types of Agitators, their Power Numbers, Design Equations and their significance in production.
Introducing or discovering the types of agitators in pharma field is certainly a revolution because different agitators will have different purposes and different advantages, but most commonly used agitators are Anchor, Propeller, Turbine, Paddle etc., and still these agitators are sub divided into types, for example Round Anchor and Anchor combined with Gate are two types of Anchor.
So, for knowing the types of agitators and their significance you don't need any basic knowledge, but just an idea that
"what is an agitator ?, And what it can do ??"
"What is the difference between Agitation and Mixing ??"Agitator : An agitator is something which is used to stir liquid or mixture of liquids.
Also Read:
How to Select a Condenser?
What Does a TR exactly means?
How to Calculate the Energy of Steam?
What it can do ?? : It can be used in various operations, in a pharma industry it can be used in multiple operations like reactions, work up's, drying, filtration, etc.,
Difference between Agitation and Mixing :
Agitation is the process of keeping a mixture that has been mixed in the proper mixed state required for the 'end' product.
Mixing refers to the actual stirring of different liquids and/or materials to blend them together into an end product or mixture. Once this mixture is 'mixed' it may require agitation to keep the mixture in the proper 'mixed' state.
So, Now i'll go into our topic,
There are two types of Agitators commonly used,
1. Mechanical Agitators, 2. Electronically Controlled Agitators, I'll demonstrate commonly used Mechanical Agitators.
Recommended For You:
How to Select Motor Capacity of an Agitator?
How to do Scale Up calculations?
How to Design an Industrial Column?
Paddle Agitators: This is one of the most primary types of agitators with blades that reach up to the tank walls. Paddle agitators are used where an uniform laminar flow of liquids is desired.
Anchor Agitators : This simple agitator consists of a shaft and an anchor type propeller and can be mounted centrally or at an angle. It is mainly used in reactors.
Radial Propeller Agitators : Radial agitators consist of propellers that are similar to marine propellers. They consist of two to four blades that move in a screw like motion, propelling the material to be agitated parallel to the shaft.
Propeller Agitators : A propeller agitator is shaped with blades tapering towards the shaft to minimize centrifugal force and produce maximum axial flow. Propeller agitators are popular for simple mixing jobs.
Turbine Agitators : Yet another type of process agitator is the turbine agitator. Turbine agitators can create a turbulent movement of the fluids due to the combination of centrifugal and rotational motion.
Helical Agitators : These agitators have blades with a twisted mechanism, just like the threads of a screw. The curves result in a vigorous motion of the fluids to be agitated. Helical agitators are most useful for mixing viscous liquids.
A simplified brief description has been tabulated below.
Agitator Type | Applications | Advantages | Disadvantages |
Paddle | * Mixing of Solids, * Slurry Mixing, * Used during Crystals forming phase during Super saturated Cooling | * Heavy duty, * Apt for Slow operation, * Can have 2 or 4 blades | * Power Consumption is very high, * Inefficient Mixing |
Turbine *Straight Blade *Pitched Blade *Curved Blade *Disk Blade | * Liquids and Gas reactions, * Highly used during Reaction and Extraction Operations. | * Generates high Radial Flow, * Highly used for dispersion operations | * Not preferred for solvents with high viscosity[NMT 20 cP] |
Screw type | * Have to use in addition to other agitators. * Mostly used in Food processing. | * Uniform mixing of High viscous masses. | * Not preferred for im-miscible solvents. |
Helical Blade *Ribbon Type *Helical Screw | * Most Probably used in Paint industry. | * Can handle Visco-elastic liquids efficiently | * Low possibility for Radial mixing |
Anchor | * Highly used in Pharma Industry for Several Operations | * Increase possible heat transfer rate in reactors, from reactor heat transfer surface to Mass. | * Required high Efficiency Gearbox, * Required high Power. |
Gate | * Highly used for blending Operations | * Provides efficient Mixing and agitation control, * Can handle Psuedo-plastic liquids. | * Not preferred when both liquids and gases combine involves |
Propeller | * Suitable for GLR's, ANFD's, can handle Corrosive materials with Glass lining. | * Will increase the homogeneity, * Can be used in two different patterns for drying and pressing. | * Need to be operated at high speed to avoid solid settlings in reactors. * Need to be operated at low speeds in drying operations. |
Diameter of Agitator: Usually the diameter of agitator depends on the Diameter of the vessel,
It is generally 1/3rd the diameter of the tank for Marine Propeller, Axial flow turbine, Turbo Propeller, Disc Blade turbine, Flat Blade turbine, Backward Blade turbine.
It is generally 4/5th of the diameter of the tank for Paddle, Anchor, Gate.
Type of Agitators and their functions:
Axial Flow Turbine, Turbo Propeller and Flat Blade Turbine have blades ranging from 3 to 6. These have tip speeds between 200 to 300 meters per minute. The diameter of impeller is 25% to 60% of tank diameter. For Axial Flow Turbine and Turbo Propeller, the angle of blade varies from 30 degrees (for less viscous liquids) to 60 degrees (for more viscous liquids). Standard angle is 45 degrees. Power requirement increases with higher pitch angle. For Flat Blade Turbine, the length of blade is 25% of diameter, and disk diameter is 60% to 70% of the diameter of impeller.
Paddle, Anchor, or Gate have only 2 blades. These extend close to the tank wall and have tip speeds between 80 to 150 meters per minute. These push and rotate the liquid in a laminar flow. There is no axial or radial mixing. The width of blade is 1/8th or 1/10th of the agitator diameter.
Number of Agitators:
There can be many number of agitators connected to a shaft, and it can be calculated as
Number of agitators = (Maximum liquid height x specific gravity) / Diameter of tank.
Gap between two Agitators = Liquid height / (Number of impellers - 0.5).Basic Design Equations for a Vertical Vessel and Agitator:
Vessel Volume = (pi x vessel dia x vessel dia x vessel length) / 4.0
Agitator Shaft length = vessel length + (vessel dia x 0.25)
For Rectangular Tanks,
Tank Volume = Vessel Length x Vessel Breadth x Vessel Height
Agitator Shaft length = Vessel Height
Based on geometry of vessel, many factors for impeller can be decided.
AGITATOR COMPARISON CHART:
Today, the major concerns of the chemical and pharmaceutical industries are improving performance and reducing production costs. Agitation, mixing and heat transfer are major factors in maximizing the efficiency of a process. The various blade designs in our agitator product range have undergone significant research and testing, making it possible to use a scientific approach to agitation and heat exchange techniques that will optimize your process. The chart below illustrates the different types of blades available and the characteristics of each.
That's it.........!! Cheers..... if you understand,
Excel Sheet has been simulated for design of Agitator and you can download it here,
Any Queries feel free to ask,
Comments are most appreciated.!
Agitators Curves for reference:
Related Articles:
Agitator Shaft length = Vessel Height
Based on geometry of vessel, many factors for impeller can be decided.
Agitator | Agitator Speed | Power Number | Pumping Factor | Impeller Diameter |
Marine Propeller | 100 - 300 RPM | * 0.3 for 3 bladed impeller, * 0.33 for 4 bladed impeller | * 0.33 for 3 bladed, * 0.34 for 4 bladed. | 1/3rd of tank dia |
Axial Flow Turbine | 100 - 300 RPM | * 1.35 for 3 bladed, * 1.4 for 4 bladed, * 1.45 for 5 bladed, * 1.6 for 6 bladed. | * 0.6 for 3 bladed, * 0.69 for 4 bladed, * 0.78 for 5 bladed, * 0.87 for 6 bladed. | 1/3rd of tank dia |
Turbo Propeller | 100 - 300 RPM | * 1.35 for 3 bladed, * 1.4 for 4 bladed, * 1.45 for 5 bladed, * 1.6 for 6 bladed. | * 0.6 for 3 bladed, * 0.69 for 4 bladed, * 0.78 for 5 bladed, * 0.87 for 6 bladed. | 1/3rd of tank dia |
Disc Blade Turbine | 100 - 300 RPM | 5.0 | 0.7 - 0.8 | 1/3rd of tank dia |
Flat Blade Turbine | 100 - 300 RPM | 5 | 0.7 - 0.85 | 1/3rd of tank dia |
Backward Blade Turbine | 100 - 300 RPM | 5 | 0.65 - 0.85 | 1/3rd of tank dia |
Paddle | 50 RPM | 5 | 0.03 | 80% of tank dia |
Anchor | 50 RPM | 5 | 0.07 | 80% of tank dia |
Gate | 50 RPM | 5 | 1 | 80% of tank dia |
AGITATOR COMPARISON CHART:
Today, the major concerns of the chemical and pharmaceutical industries are improving performance and reducing production costs. Agitation, mixing and heat transfer are major factors in maximizing the efficiency of a process. The various blade designs in our agitator product range have undergone significant research and testing, making it possible to use a scientific approach to agitation and heat exchange techniques that will optimize your process. The chart below illustrates the different types of blades available and the characteristics of each.
That's it.........!! Cheers..... if you understand,
Excel Sheet has been simulated for design of Agitator and you can download it here,
Any Queries feel free to ask,
Comments are most appreciated.!
Agitators Curves for reference:
Note: Some of the Data Interpreted here is not of my own, but from a generous Genius "Satish Lele"
Related Articles:
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How to calculate Distillation Time cycle ?
How to select a Vaccum pump ?
How to Calculate Volume occupied by Torispherical Dish ?About The Author
Hi! I am Ajay Kumar Kalva, Currently serving as the CEO of this site, a tech geek by passion, and a chemical process engineer by profession, i'm interested in writing articles regarding technology, hacking and pharma technology.
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Follow Me on Twitter AjaySpectator & Computer Innovations
Hi! I am Ajay Kumar Kalva, owner of this site, a tech geek by passion, and a chemical process engineer by profession, i'm interested in writing articles regarding technology, hacking and pharma technology. 
which utility is suitable for condensing acetone vapours under vacuum and under atmposphere in condensor...chilled water 8 deg. centigrade or brine -10 degree centigrade..
ReplyDeleteHey Mr.Anonymous, if you are having two condensers, then go with chilled water for primary and chilled brine for secondary,
Deleteand if you are able to maintain the vapour temperature above 15 deg C under vacuum, then go with -10 degC Brine or 5 degC chilled water, if the temperature below 15 degC then use chilled brine at -20 degC, and in case of the vacuum distillation, remember to have a equalisation line from secondary condenser to collection receiver,
if the distillation is an atmospheric one, directly go with RT water at below 30 degC,
Can you explain theoretically and calculate and tell how to select utility as per the above post.pls. give ur mail id so that i can share the sketch..
Deleteusing a better utility for condenser will enhance the rate of distillation, for a chilled brine at -10 deg C, the temperature difference can be considered as 7-8 deg C, and for a utility like chilled water having a inlet temperature of 8 deg C, the temp difference will be around 3-4 degC, because the reaction mass temperature will be around 15-20 degC under vacuum, so mostly the vapours will reach equillibrium with utility outlet, and in the process of condensing the vapour will exchange only latent heat, whereas in case of -10 degC brine, there will be exchange of sensible heat also, and if you want to calculate it theoretically then read the post in this link, then you will get a clear idea,
Deletehttp://pharmacalc.blogspot.com/2016/09/how-to-calculate-rate-of-distillation.html
try to do a reverse calculation basing upon the fixed rate of distillation and find the LMTD of both cases, which uses brine at -10degC and chilled water at 8degC, then you will come to know the difference.
Hello sir,
ReplyDeleteI am chemical engineering student I am doing my final year project on extraction of oil from slurry in oil refineries.can you suggest us some ideas
so i think, it is something like Lube oils refining, right??
ReplyDeleteThats a good one, and i too tried that during my project but finally got diverted, Give your best good luck,
and regarding extraction any possible help i'll do, mail me @ pharmacalc823@gmail.com
Please tell me how to do piping? How to design pipeline Header and Tappings from it?
ReplyDeleteA x V = A1 x V1 + A2 x V2 + A3 x V3 +......................
DeleteBut, V = V1 = V2 = V3 = .............. [this is as per thumb],
A = A1 + A2 + A3 +................
D^2 = D1 ^2 + D2 ^2 + D3 ^2 + ..............
that's it,
the number of tappings given should satisfy the above derived eqn.
Regards,
PHARMA ENGINEERING
what is the major difference between impeller,propellerand agitator
ReplyDeleteMostly there wont be anything like a Propeller, may be i've mentioned above that's just for understanding purpose, because Propeller is what you see in a table fan, and the agitator that was usually called as propeller in pharma industry is strictly called as Retreat curve agitator,
DeleteComing to your question, Impeller is nothing but an agitator, and for example if an retreat curve is having two agitators then it is said to have 2 impellers.
That's it.
How can we calculate power for propeller & anchor used in glass lined reactor....
ReplyDeleteLet it be a 10KL GLR, and the dia be 2.5m, and RPM is 110, by thumb dia of propeller will be 1/3rd of reactor dia,
DeleteFor Propeller,
D = 2.5/3 = 0.83m, N = 110 rpm, rho = 1000 Cu.m / Kg, Np = 1.5
P = 1.5 x 1000 x ( ( 110/60 ) ^ 3 ) x ( 0.83 ^ 5 ) = 3641 Watts = 3.64 KW,
For Anchor.
D = 2.5 x 0.8 = 2m, N = 48 rpm, Np = 5,
P = 5 x 1000 x ( (48/60) ^ 3 ) x ( 2 ^ 5 ) = 81920 Watts = 81.9 KW.
That's it..........!!!!
Hi,
ReplyDeleteGreat site, and great work.
We are a 30 year old manufacturing firm specializing in chemical and pharmaceutical reactors. We are currently looking for professionals who can independently design agitators for the process and mechanical aspect. If you know any such individuals, please ask them to reach out to me at anuj@thermotechengg.com.
Cheers
Anuj
how can we design spray ball ..how to select number of holes and flow from holes in spray ball?
ReplyDeleteHello, as like previously mentioned, A*V = ( A1 * V1 ) + ( A2 * V2 ) + ( A3 * V3 )+................,
DeleteV = V1 = V2 = V3 = ............,
So, A = A1 + A2 + A3 + ........,
(D^2) = (D1 ^2) + (D2 ^2) + (D3 ^2) + ........,
D is line size, D1, D2, D3,....... are nozzle sizes, for how many nozzles the equation satisfied, those many nozzles you need to consider for a spray ball.
Regards,
PHARMA ENGINEERING
Great site sir I have ever seen ... Definitely I will mail ot post my queries....
ReplyDeleteParth Panja
Kolkata
Thanks and you can feel free to comment your queries.
DeleteRegards,
AJAY K
How agitator speed is calculated??How you can say in the previous problem that for Anchor type agitator RPM=48 and for propeller rpm=110??
ReplyDeleteThose are basic things Pratim, Usually an anchor will have RPM of 36/48, a propeller will have from 96/110, a PBT will have 96-140.
DeleteIf you wanna calculate them then use the power to power number relation and consider physically available cases in your industry for getting diameters.
Regards,
AJAY K
So if I have to design an PBT agitator for a reactor,can I fix the value of rpm in between 96 to 140??Then can I calculate the power of the motor required to drive the same agitator based on the rpm?
ReplyDeleteDear Pratim,
DeleteRegarding an agitator design all you can do is managing the L/D ratio, simply sweep dia you have to fix, then no of agitators, these can be calculated based on a formula,
No. of agitators = Z x rho / D,
Z - reaction mass height, rho - density, D - inner dia of reactor/vessel.
RPM can be adjusted based on the Gearbox ratio, motors RPM will be either 1475 or 2900,
usually motors with 1475 RPM will be preferred for reactors, and 2900 RPM motors used for centrifugal pumps,
As mostly all reactors shall be equipped with VFD(Variable frequency Drive) at any time you can adjust the RPM.
Power = Np x ( N^3) x (D^5) x rho.
For more infor on motor capacity selection for an agitator, follow this link,
https://pharmacalc.blogspot.in/2016/05/motor-selection-for-agitator.html
Regards,
AJAY K
please let me know any example for no of agitators, calculated based on a formula,
DeleteNo. of agitators = Z x rho / D,
I dont understand
Dear Sir,
DeleteZ is the liquid height in the reactor, rho is the density of solvent/rxn mass, D is the dia of reactor,
Lets say, ours a 10 KL reactor, with height of 2.54m & dia of 2.4m.
Lets assume liquid height of 2m, and reaction solvent is toluene, so
no of agitators will be 2 x 0.868 / 2 = 0.868 ~ 1 impeller.
that means one impeller is enough for the agitator.
Hope you understand,
Regards,
AJAY K
Thank you Mr Ajay
DeleteI mean that one impeller means one blade for agitator
In an In-process reaction, 60kg ammonia gas is needed to purge to the liquid phase reaction in a reactor.If I am going to calculate the total volume of the reaction mixture in litre(including ammonia) then how I will take the amount of ammonia as it is the gas phase and when it will take to solution it would liquify? Please help me Sir
ReplyDeleteAt what temperature you are purging??
DeleteBased on the temperature below are the densities,
-50 degC - 695Kg/Cu.m,
0 degC - 636 Kg/Cu.m,
20 degC - 609 Kg/Cu.m,
50 degC - 561 Kg/Cu.m.
If its 20 degC, then 60 Kg / 609 Kg/Cu.m = 0.0985 Cu.m = 98.5 L.
Regards,
AJAY K
Thank you so much Sir...I am really greatful to you...
ReplyDeleteI am working as a process engineer at an mnc pharma company,just joined.. unexperienced,that is why I am facing some problem.Please sir keep in touch..
ReplyDeleteI'll be in touch with my site, you keep on visiting, that's it.
DeleteRegards,
AJAY K
Sir,how debottle
ReplyDeletenecking is performed?
It can be done on several ways, by having a change in equipment or change in process, or adding one more equipment, de bottle necking means it may be regarding time-cycle / quality / yield / anything that may be a hurdle in a process to overcome.
DeleteRegards,
AJAY K
My company has two sites...From one site, a process flow chart of a standardized product has come to my site and I have the responsibility to take that product in my site, depending on the equipment facility,capacity I have to take the batch in my site there by I have to fix the batch size. So sir what di you think what way would be better to go?Is there any data TT data required from another site or how much size of batch would be better to take trial?
ReplyDeleteBefore taking a batch, compare the equipments from transferee site to transferrer site, if the equipments were like to like including agitators, MOC, L/D ration & occupancy of reactors, filtration area of equipments, dryer's occupancies, then you can take a direct batch. or else go with a trail batch by ensuring minimum similarties like MOC & occupancy.
DeleteTT data includes safety studies like RC1 data(Heat of reaction), DCS study(Decomposition temperatures & Enthalpy), ARC studies, powder safety data(MIE & Burning class).
QbD(Quality by Design) studies and Design space report to have a better knowledge on the reaction parameters which effect yield and quality.
Previous failure history of the product in their site.
These are most recommended Doc's that need to be considered exchange during TT.
Regards,
AJAY K
Please help Sir
ReplyDeleteIs it possible to get fine Crystal in glass reactor in the time of crystalization??By changing geometry of agitator?
ReplyDeleteGo with an Anchor with 48 RPM
DeleteRegards,
AJAY K
Any explanation??Why does it so happen?
ReplyDeleteThere are 4 types of agitation[defined based on scale of agitation],
Delete1. Mild,
2. Normal,
3. Vigorous,
4. Violent.
For an anchor, if the anchor is having an RPM of 48, it will e either Vigorous / Violent, based on the occupancy. If the occupancy is about 60-80% then it will be violent.
If the RPM is either violent / Vigorous, then the crystal size will come fine.
Regards,
AJAY K
let me know I have one process was demanding to convert amorphous to crystalline i preferred that anchor 48 RPM occupancy 35% what will happen if occupancy increased
Deletealso tell me what will happen if im going with PBT/RCB with low RPM with high or low occupancy can i get the desired form and PSD
Dear Sir,
DeleteThere wont be severe impact on the product nature based on agitator, but the forming crystal growth depends upon the agitator RPM, As you have mentioned that occupancy is ~35%, so if its Anchor reduce the RPM between 25-28, if its a PBT / RCI reduce them to 40-45. Then the crystal growth shall be good.
First of all, as a process engineer we need to think about the yield, that shouldn't be lost during filtration in form of fine crystal through ML's, then after we can think about the PSD by going through jet milling etc.
Regards,
AJAY K
Thank you Mr Ajay i will be touch you
DeleteIs there any thumb rule how to calculate minimum stirring volume of a certain capacity (e,g 5kl) of reactor?
ReplyDeleteThere wont be any thumb rule for calculating MST, but you can use bottom extension teflon blades to ensure your required MST.
DeleteRegards,
AJAY K
what is tips speed exactly sir???
ReplyDeleteTip speed is just nothing but product of sweep dia and agitator speed
DeleteRegards,
AJAY K
Please sir reply how order of the reaction influence in scale-up?
ReplyDeleteI don't have enough knowledge about Scale-up vs reaction order, Infact being frank upto my experience i've heard about these things.
DeleteRegards,
AJAY K
But sir frankly speaking in an interview of torrent pharma ltd I have been asked this question from their AGM
ReplyDeleteSir is it possible to calculate the time taken for distillation of 1000L acetone from a reaction mixture?Or any other data is required??
ReplyDeleteWhats the total volume of reaction mass?, whats the MOC of reactor?
Deletewhats the capacity of reactor?
Regards,
AJAY K
How cycle time & debottlenecking is performed by using recovery solvents?
ReplyDeleteIt would be better sir if you give explanation using an example
ReplyDeleteRefer this post.
Deletehttp://pharmacalc.blogspot.com/2016/03/theoretical-way-to-determine-time.html
Regards,
AJAY K
What is best possible way to centrifuge sticky reaction mass?
ReplyDeleteDear Pratim,
DeleteMove with a low RPM i.e., ~300 during feeding, Expel the ML's at 600 RPM, wash the material at 400 RPM, Spin dry the material at 700 RPM followed by 900 RPM finally, its a sticky mass means the pH should be above 12 i think.
Regards,
AJAY K
What is the necessaity of nitrogen rotameter in PP area?
ReplyDeletewhat does PP means??
DeleteWhy final crystalization stage is done separated area?
ReplyDeleteUsually atmosphere pressure will be 760 torr,
DeleteAnd to avoid any foreign particles from contaminating the product, final stage shall be done at clean rooms,
The reason behind having many rooms in a clean room is,
The main entrance shall be maintained at 768 torr, the next to entrance room shall be maintained at 774 torr, the production room / powder processing room shall be maintained at 780 torr, i.e., when you open the door of the production room then due to high pressure when compared to other room there is only chance of one way particle transfer i.e., from 780 torr room to 774 torr room, and when you open the door from 774 torr room, particles will transfer from 774 torr room to 768 torr room,
and no two doors can be opened at the same time.
Thats it
Regards,
AJAY K
PP area means Powder processing area
ReplyDeleteIn powder processing areas, usually you need to purge nitrogen but not flushing, because flushing may disturb the particle count, which need to be maintained mandatorily
DeleteRegards,
AJAY K
hello sir, can u please help to what the process engineer role in pharma and what is the basic knowledge for process engineer
ReplyDeleteTo increase yield of a batch process generally what parameters should be manipulated? What basic ideas/thoughts should keep in mind??
ReplyDeleteDear Pratim,
DeleteThis seems to be a general question, be specific, so that i can answer, gimme any process outline with parameters, so that i can explain you in detail.
Regards,
AJAY K
In reactor when a reaction mass is thick,difficult to take in centrifuge through outlet of the reactor,what precautions should be taken or what modification on the lining between the reactor and cf should be taken?
ReplyDeleteDear Pratim,
DeleteUse a flush bottom valve at reactor bottom, at what temperature and pH you are trying to filter the mass ?
avoid any negative bends in the line, better have a straight line from reactor bottom to centrifuge, dont reduce the line size from reactor bottom to centrifuge, is possible use a metering pump, if the temperature of filtration is above RT then add hot / cold insulation to the line, as every one knows reduce the RPM of reactor while feeding, so that you can achieve continous flow, maintain the centrifuge RPM between 300-400.
Regards,
AJAY K
Sir how utility calculation of a batch is performed??
ReplyDeleteDear Pratim,
DeleteBe specific to me, vacuum, steam, RT water, chilled water, Power, Chilled brine, liquid nitrogen, Nitrogen, Instrument air were all considered as utilities in our pharma field, so about which utility shall i need to discuss about.
Regards,
AJAY K
About vacuum and chilled brine??
ReplyDeleteApprox for a 200kg batch size(suppose there are a drying operation where 650mm Hg vacuum is required and for another one steps where 0-5℃ temp is required for 300kg reaction mass),how would I approach to calculate how much vacuum and chilled brine will be required??
ReplyDeleteIn first case, whats the solvent you want to remove and in second case,
DeleteLets the mass weight be 300 Kg and let the volume be 3000 L, then you need to calculate the TR required for cooling the mass to 0-5℃, i.e.,
[ 3000 x 1 x 0.5 x ( 30 - 0 ) ] / 3024 = 14.88 TR,
If u need to calculate the time of cooling or heating pl read this post: http://pharmacalc.blogspot.com/2016/04/calculate-time-cycle-required-for-heating-cooling.html
Regards,
AJAY K
Sir normally what is load calculation for pharma industry??
ReplyDeleteDear Pratim,
DeleteBe specific.
Regards,
AJAY K
Sir I have been given a task to prepare a solvent monitoring report which includes consumption of solvent(fresh+recovered) for every product producing in our plant and also make a plan how amount of consumption of fresh solvent is reduced and use more recovered solvent so that saving can be possible on solvent consumption.As per standard process requirement we can not reduce the amt of solvent requirement for a batch(reaction/washing/extraction etc).So as a process engineer how would I approach or in which area I would focus to reduce amount of feesh solvent consumption???Please sir give me suggestion
ReplyDeleteDear Pratim,
DeleteUse fresh solvent for reaction, and recovered solvent for washing / extraction.
Regards,
AJAY K
how to calculate vacuum required for a batch?
ReplyDeleteDear Pratim,
DeleteBased on solvent boiling point and material senstivity.
Regards,
AJAY K
Generally we know that pumps deals with liquid and compressor deals with air/gas then how we can use vacuum pump for creating vacuum by driving off air??
ReplyDeleteAnd how oil rings vacuum pump operates??(Is it operated by circulating oil?)
Dear Pratim,
DeleteAn oil ring rotary vane vacuum pump has an impeller with blades attached to a center hub, located in a cylindrical body, but off-set from the center. When the pump starts, the impeller slings the liquid sealant by centrifugal force, to the outside walls of the body, forming a ring of oil at the outside walls of the body creating suction which is created in the connected system through a filter housing.
Regards,
AJAY K
How would I calculate amount of chilled brine required for chilling(0-5℃) operation?
ReplyDeleteSir suppose for a batch of 1kg in pilot there is step to heat up the reaction mass of volume 3lit from 30℃ to 70℃ which takes time 1:30hrs (In a Glass assembly of 5.0 L, depending on thermal conductivity etc).Then for same batch if take it in commercial scale of batch size 100kg and of the said step is taken in a GLR of capacity 1.0KL how much time it would to reach 70℃?? I possible show the calculation for this scale up please consideeing increase of heat transfer area etc..
ReplyDeleteTaking toluene as solvent.
Steam pressure 3.5kg/cm2
Steam temperature=100℃
Dear Pratim,
DeleteReaction mass volume is 600 L, major solvent is toluene,
1 KL will have a HT area of 4.25 Sq.m,
Effective HT area(A) will be 4.25 x ( 600 / 1000 ) = 2.55 Sq.m,
LMTD = ( ( 100 - 30 ) - ( 100 - 70 ) ) / Ln ( ( 100 - 30 ) / ( 100 - 70 ) ).
= 47.17 degC.
Sensible Heat (S) = 600 x 0.868 x 0.4 x ( 70 - 30 ) = 8332.8 KCal.
Time = 8332.8 / ( 120 x 2.55 x 47.17 ) = 0.577 hr = 34.62 mins.
If you want to calculate based on the glass lined properties, then
you need to calculate K x A x dT / X = 1.03 x 2.55 x ( 70 - 30 ) / (2.2 x 10^-3) = 4918.72 KCal/hr.
That means a GL surface can trnasfer 4918.72 KCal of heat energy in 1 hr.
So it will take 8332.8 / 4918.72 = 1.69 hrs = 102 mins for transferring 8332.8 KCal heat energy.
Regards,
AJAY K
Hi Ajay,
DeleteYou have taken heat transfer area 4.25 sqm for 1 KL. Can you plz tell me how ?
What is K=1.03 and X .... Plz dont mind, i am a chemical engineer by profession but my concepts are weak.
DeleteHello Sir,
ReplyDeleteI am working at Lupin Ltd..
In one of our product, the isolation is done in centrifuge..The CF is SS 48".. The issue is the wet cake becomes hard and during unloading we need to use scrapper which causes the CF bag damage..
Is there any means available by which we can avoid the usage of scrapper..
The solvent is chloroform..
Please reduce centrifuging time or reduce rpm.But this will result in retention of some chlorofoem in product.It is a question of standardization.
DeleteHere whose overall heat transfer coefficient value is 120 which you have used??
ReplyDeleteGLR
DeleteSir you have written in the above statement against my question that
ReplyDeleteTime = 8332.8 / ( 120 x 2.55 x 47.17 ) = 0.577 hr = 34.62 mins.
Again you have calculated time required to reach 70℃ ,it will take 8332.8 / 4918.72 = 1.69 hrs = 102 mins for transferring 8332.8 KCal heat energy.
Then my question is what does the time value of 1st time signify?
Dear Pratim,
DeleteThe first calculation is based on the over all heat transfer coefficient of the reactor, this may vary based on scaling and fouling factors,
and the second calculation is based on the thermal conductivity of the reactor MOC.
Regards,
AJAY K
Then Sir which one of these would be better to take into consideration?
ReplyDeleteAs per my theory i'll go with the MOC thermal conductivity.
DeleteRegards,
AJAY K
Sir,I can't understand this calculation,I have done it in paper but doesn't match with your result..
ReplyDeleteyou need to calculate K x A x dT / X = 1.03 x 2.55 x ( 70 - 30 ) / (2.2 x 10^-3) = 4918.72 KCal/hr.
Please show the calculation..It may be unit problm
Dear Pratim,
DeleteSorry, that's a wrong calculation i've done over there, it is 47754.54 KCal,
So, its gonna be, 8332.8 / 47754.54 = 0.174 hr = 10.47 mins.
Regards,
AJAY K
Ok sir ....Sir in which unit you have taken the conductivity value 1.03??
ReplyDeleteHow it is assumed?? Please rply
Dear Prathim,
DeleteFor a MSGL surface, K holds 1.2 KW/m.K, which is equal to 1.03 KCal/hr.m.K
Regards,
AJAY K
I have a doubt about this problem..Sir,I am giving an example
ReplyDeleteIn our plant in a certain process there are 660lit toluene,165 kg ethyl cuma rone crude are charged into a 1.0kl glr to heat up to 102℃.Steam is available at 145℃ (inlet temp) and outlet temp around 70℃.Accroding to practical process it normally takes 90mins to reach around 102℃..But when I am going to calculate by the above process that you have written here it takes just around 10 mins...How this is possible sir even we assume fouling...???
Dear Pratim,
DeleteI think initially you have given some different input, and this input is different, anyway lets do it now,
Solven t: toluene, Volume: 660 L, Reactor caapcity :1.0 KL MOC: GLR,
Steam in: 145 degC, initial mass: 30 degC, final mass temp: 102 degC,
Toluene density 0.87 Kg/L, Specific heat: 0.45 KCal/Kg.K,
U : 120 KCal/hr.Sq.m.K, Effective HTA 2.81 Sq.m, Time for heating is: 1.13 hr = 67.7 mins
Use this sheet for calculating the time for heating/cooling:
https://drive.google.com/open?id=0Bxh-62TvI01VQ3RISWRMR3I5NFE
Regards,
AJAY K
Ok sir...Sir how you have taken the solid 165 kg ethyl cumarone mass into above calculation??I mean its Cp value and it's density ??
ReplyDeleteThats mass will be dissolved and wont have that much impact on our calculation, there will be slight variation in the specific heat, thats it.
Deletebecause the volume of the compound is far low when compared to that of the volume of toluene.
Regards,
Ajay K
Sir preciously you have said that as per your theory for time calculation better to go with moc thermal conductivity approach but here you have calculated as per heat transfer coefficient concept...Why is it so sir?Any special purpose
ReplyDeleteWhile calculating with thermal conductivity, it doesn't need any data like fouling factors, or scaling thickness, it is pure theoretical, and if you want to proceed with overall HT coefficient, it is defined based on the above mentioned factors. once read this post: http://pharmacalc.blogspot.com/2016/05/overall-heat-transfer-coefficient-Calculation.html
DeleteThats why i've mentioned its better to go with thermal conductivity.
Regards,
AJAY K
Sir if we calculate time by moc thermal conductivity approach then what will be the result??
ReplyDeleteThe result will be pure theoretical and it is subjected to descaled equipment's. Surely it will vary based on fouling and scaling.
DeleteRegards,
AJAY K
Please show the calculation
ReplyDeleteFor which solvent we would go for flash distillation and for which we go for fractionation??
ReplyDeleteFractionation and flash distillation were mostly applicable for petroleum industries,
DeleteBut in pharma industry, mostly we have vacuum distillations only, some times we will collect the low boils and high boils in some product manufacturing, so those can be considered as fractionation and regular single solvent distillation is considered as flash distillation.
Regards,
AJAY K
What is G force for centrifuge??
ReplyDeleteIs it wR^2?
How it affects in cf?
Cf = ( omega ^ 2 ) x r - Centrifugal force.
DeleteOmega - angular velocity(rpm).
Higher centrifugal force favors higher rate of filtration, but it shouldn't be done in continuous flow, it should be applicable for only for batch process, i.e., spin dry.
Lower centrifugal force favors optimized rate of filtration, this is applicable for feeding operation.
Regards,
AJAY K
How we calculate time required for performe cf operation for a certain mass of reaction mass and certain bd suppose 1.6 gm/c.c and having mass 1000kg
ReplyDeleteI'll explain you the formula, pl try to calculate, still any queries while calculating use the forum page available in this site and pl start a new thread(instead of commenting),
DeleteRate of filtration = { rho x (omega^2) x [(R2^2) - (R1^2)] }/{2 x myu x X }
X = [(M x A / Al x Ak) + (R/A2) ].
rho - reaction mass density, omega - angular velocity(RPM)
myu - viscosity of solution, M - solids conc in reaction mass,
A - Specific cake resistance, R - filter cloth resistance,
Al - log mean of cake area : 6.28 x b x (R2 - Ri) / ln(R2/Ri),
b - centrifuge basket height, Ak - arithmetic cake area : 3.14 x b x (Ri+R2),
A2 - 6.28 x R2 x b,
R1 - distance between centrifuge center to the liquid surface over cake,
Ri - Basket dia - cake dia.
R2 - Basket Dia,
Regards,
AJAY K
After calculating TR for a chiller plant how we will calculate it's costing depending on current consumption??
ReplyDeleteDear Pratim,
DeleteA brine chiller of capacity 150 TR consumes 400 amps current per hour,
Use power formula, P = V x I x Cos(phi).
V is voltage in volts, I is current in amps, Cos(phi) is power factor, usually it will be around 0.85 - 0.90.
Commercial power supply will be 440 V, for domestic purpose it will be 240 V.
P = 440 x 400 x 0.85 = 149600 watts = 149.6 KW.
For commercial it will be 3 phase supply, so P = 1.732 x 149.6 = 259.1 Kwatts.
For commercial purpose, 1 unit costs about Rs. 9/- i.e., 2331.9 /- .
So for 150 TR the consumption is 2331.9 /-.
And along with this you will have a compressor running for ammonia and a motor running in evaporative condenser.
Based on their motor capacities, calculate the same .
That's it, these are maintainence costs apart from the methanol and water costs.
Regards,
AJAY K
Sir you have told that "A brine chiller of capacity 150 TR consumes 400 amps current per hour," but sir TR to amp conversation first we need to TR with 12400 to get total BTU then multiply it with .293 to get watt then divide it with volts(for commercial 440) then we get amps as amps=watt/volts...In this method for 150TR amps getting differ form your result... Sir please tell me how you have calculated the 400amp for 150TR
ReplyDeleteDear Pratim,
DeleteNever convert the TR into Amps, in my previous comments i mentioned you the chiller capacity is 150 TR and it took 400 amps, it may vary from medium to medium, like brine to chilled water.
Regards,
AJAY K
Ok sir...
ReplyDeleteSir how bulk density of the reaction mass/wet material (after cf followed by drying operation) has its effect on pharma production?
Bulk density indirectly effects the time cycle and investment costs,
DeleteIf the bulk density is high then the cake volume will be less, then automatically the equipment used for the process requires low capacity.
and it can impact the time cycle, by reduction of filtration lots, drying lots.
Regards,
AJAY K
What are the preventive tools that must have a reactor for safely operation?
ReplyDeleteNot tools, those are called instruments, PRV & RD's are extensively used for safe operation in reactor, not only reactors but also they can be used for most of the vessels to relief the pressures which are developed due to the breathing losses, reactions or sometimes during inertization.
Deleteregards,
Ajay K
Please say something about RC1,DSC and MIE study??What sort of info we can get from those experimental data?
ReplyDeleteDear Pratim,
DeleteRC1 data indicates the energy liberated/required during an addition or during a reaction.
But where as, DSC study indicates the Onset & Peak of decomposition temperature, sometimes it indicates the endotherms also.
MIE value will indicate the static energy generation probability, if it is low then it required more controls.
Regards,
AJAY K
Response please Sir
ReplyDeleteDear Pratim,
Deletepl start a discussion through new topic thread in the below forum, instead of commenting.
http://discussion-forum.80757.x6.nabble.com/
Regards,
AJAY K
Supoose Design pressure of a reactor is 4kg/cm2,then approximately what will be the set pressure of the safety valve of that reactor if I want to install?
ReplyDeleteDear Prathim,
DeleteFor PRV it shall be 2.75-3 Kg/cm2, for RD it will be 3.0-3.5 Kg/cm2.
Regards,
AJAY K
would PRV & RD be installed on the same line or separate lines?
DeletePRV & RD should be placed parallely, they shouldn't be installed in series.
DeleteResponse please Sir
ReplyDeleteSir,why generally baffle is not used GLR?? Because of not having sufficient strength to hold baffle or any other reason??
ReplyDeleteDear Pratim,
DeleteUsually the GLR surface will be high sensitive, and it will be difficult to arrange baffles with support from GL surface, and if any hanging baffles were arranged, then there may be a chance of glass lining damage if those were detached during process operations leading to unsafe situation.
Hence, considering the safety issues, the baffles concept is terminated.
Regards,
AJAY K
hello, I have 2 tanks of 20000 litre and 50000 litres ,have to mix salt with the water so which type of agitator should be useful....please suggest
ReplyDeleteDear Shivam,
DeletePl go with the agitator having least bottom clearance / minimum stirring volume, as salt is highly soluble in water, there wont be any issue with mixing pattern,
Preferably go ahead with gate anchor.
Regards,
AJAY K
Sir
ReplyDeleteI Mechanical engineer in my agitator I have 2 sets of hydrofoil blade (each set contains 3 blades) and one set of curved blade at bottom there is always faliure of blade breaking in it ( this agitator agitates slurry of sodium bi sulphate) and brg failure (taper roller) I am unable to find out reasons of such faliure ....
May you help
Sweep dia 1250mm
Tank dia 2500mm
Tank height 4000mm approx
Distance B/n two set of blade vertical 1100mm
Sir in our plant water is circulated by a pump with flow 3.5m3/hr and discharge press 3kg/cm2 to ,a venturi is attached with the circulation line to receive vacuum in receiver from there vacuum is supplied to the plant,pipe sizing of the circulation line is 2"..You can say it is water ejector system. sir my question is is there any calculation to find out what maximum vacuum can be generated by this system??Pls response sir...
ReplyDeleteDear Pratim,
Deleteit is simple to determine the ejector capacity, as already you have mentioned its a venturi, go with below formula,
Capacity = C x A x ( ( 2 x dP / ρ ) ^ 0.5 ),
C - Coefficient of discharge = 0.98
A - Cross sectional area of venturi,
dP - Pressure drop across venturi,
ρ - Vapour density of solvent.
Regards,
AJAY K
Thank you Sir..I have calculated the value of P1-P2=2.97 kg/cm2 ..P1=3kg/cm2 developed by the pump which will be same at upstream of venturi and P2 will be the pressure at downstream that means in throat of the venturi.Lowering the pressure at throat is the main cause of generating vacuum..So from the above P2=.0291 kg/cm2 or 22.1 mmHg that means vacuum generated is 760-22.1=737 mmHg ...Am I right Sir??? Please response...
ReplyDeleteyeah.....
DeleteWhat are the conditions required for getting different types of agitations like mild
ReplyDeleteNormal
Vigorous and violent on maintaining what parameters we can get different type of agitations
Dear Rama,
DeleteThese conditions can be created by varying the turbulence,
If we need to create these conditions by varying RPM, we need to have different agitators, and also with the help of baffles we can create that.
Regards,
AJAY K
How to calculate steam temperature by its pressure for reactor utility
ReplyDeleteHiii Keyur,
DeleteRefer this post,
http://pharmacalc.blogspot.com/2018/04/steam-tables.html
Best Regards,
AJAY K
Hello sir,
ReplyDeletewhat are the design equations of CSTR?
Can you share the reference materials for these data, charts and other contenet.
ReplyDeleteHello Yakesh,
DeleteAttached the charts of various agitators for your reference.
Best Regards,
AJAY K
Can you share reference books for these data.
DeleteThere are no reference books buddy, collected from some sites
DeleteHi Ajay,
ReplyDeleteIn my currrent company I have to select the type of agitator for MSGL where in solid liquid reaction to be done.
Can you help me in this regard,
Thank you
Hii Nikhil,
DeleteI'll do the best possible, mail me at pharmacalc823@gmail.com
Regards,
AJAY K
Dear Sir,
ReplyDeleteHow we can calculate viscosity of reaction mass?
Hi Ajay,
ReplyDeleteI'm currently designing a propeller flow meter that has to measure the discharge( flow rate) of water in a pipe. My problem is how to determine or should I say how to calculate the minimum force required to start rotating the propeller. Considering that the water will just be free falling. I would also like to know what else to consider when designing this.
Can you please help in this regard,
Thank you
Hi,
ReplyDeleteWhat are the recommended velocities for different utilities in pipe line sizing .