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Slurry Pump

Slurry Pump

(OP)
I am working on a project as an intern in a steel manufacturing plant. There is a slurry pump namely VASA-284/100. I am unable to find any proper information and formulations required for the calculation regarding slurry pump, its discharge, its efficiency and other parameters. I was hoping to gain some guidance her.

Thank You in advance
Chaitanya

RE: Slurry Pump

The pump was originally a product of Sala International manufactured in Sala Sweden. Has been sold and would have new name - you will have to search the internet to find out who, where etc. Check "Sala Pumps" to start with.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: Slurry Pump

(OP)
Can you guide me in calculation part?

Chaitanya

RE: Slurry Pump

No, you need the hydraulic performance of the pump before you can do anything and then you need the duty you are trying to achieve.

I've got a Nissan car, can you please tell how fast I drive and how long it takes to drive to the super market????

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: Slurry Pump

(OP)
I have got the following details
power - 30kW
line length - 30m
pipe dia - 10cm
no of bend elbows - 3
suction head - 20m
delivery head - 1m
density of solid - 2.5tonnes/m^3
weight of solid - 96tonnes
avg. particle size - 150µm
sp gravity of solid - 2.5g/cm^3

i tried calculating but i got result of only slurry velocity, limiting settling velocity, slurry discharge, i can't figure out how to calculate the pumping power required, wheather the pump is sufficient on its own or it requires a booster pump?

Chaitanya

RE: Slurry Pump

Pump curve?

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: Slurry Pump

You need to calculate your head loss. There might be too much loss in the line for the pump to pump up the delivery head.

RE: Slurry Pump

Specific gravity is a ratio and should have no units.

RE: Slurry Pump

If suction head really is 20 metres, that is if the pump is 20 metres above the slurry , that will be a problem.

Regards
Ashtree
"Any water can be made potable if you filter it through enough money"

RE: Slurry Pump

Chaitanya,

Your data as supplied leaves a bit to be desired
Based on the sheet below
http://valveproducts.metso.com/documents/pumps/Bro...

power - 30kW - motor size from data sheet
line length - 30m - Are you serious? This seems very low for such a big pump
pipe dia - 10cm - ~OD, ID, material? This is a 4 " pipe?
no of bend elbows - 3
suction head - 20m - Do you mean this is 20m of positive head coming into the pump?
delivery head - 1m - Assume you mean elevation difference, but what is end pressure / discharge pressure?
density of solid - 2.5tonnes/m^3
weight of solid - 96tonnes v- - What does this mean? pointless without a time span or explaination
avg. particle size - 150µm
sp gravity of solid - 2.5g/cm^3

Missing - flowrate and end connection pressure / head

The data seems to show you will have a desired flowrate between 60-120 m3/hr at a differential head of 20-30m.

That sort of head with a 30m long 4" pipe doesn't stack up.


You might find this useful http://www.metso.com/miningandconstruction/MaTobox...

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Slurry Pump

Chaitanya,

A little detail that has not yet been mentioned in this discussion....

I have dealt with METSO slurry pumps before. What is not understood by many newbies is that METSO pump curves are typically offered with various speeds noted.

Because you are dealing with reuse of an existing pump, you must know your existing motor speed and belt speed ratio to obtain the true operating speed of your pump.

Only then can you evaluate the correct pump curve and possibly consider a new speed ratio.

Tell us more about your setup including motor speed and pulley diameter ratio.

Is the pump controlled by a VFD ?

Regards

MJCronin
Sr. Process Engineer

RE: Slurry Pump

LittleInch, the METSO pumping manual is fantastic and a must read for anyone involved with pumps, not just slurry pumps, couple this with the attached Weir/Warman slurry pumping info. you couldn't ask for anything more.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: Slurry Pump

Chaitanya, suggest you re-evaluate the whole enquiry and put together some meaningful information, exactly what you are trying to do, what's the process, pumping from where to where, pump detail /speed, etc, you might get some useful info.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: Slurry Pump

You will find the nomograph on page 4 of this link to be helpful for determining minimum slurry velocities. For your D50, you will need a minimum of 40 m/hr to keep your solids suspended. If your solids are poorly graded, I recommend designing to the D80. Without clarification if your suction and discharge heads are lifts or depth of fluid above the suction or discharge, as LittleInch points out, it is difficult to provide an answer. Nevertheless, assuming this pump, it appears that you will be on the high end of the pump curve and probably experience inefficiencies and high torque. You have plenty of power.

I used to count sand. Now I don't count at all.

RE: Slurry Pump

(OP)
Thank you for your replies i will read the manuals and do more study regarding this topic.

Thank you
Chaitanya

RE: Slurry Pump

Not much further forward I'm afraid - these are the details I posted above. Please go through the posts above and answer as many of the questions as you can. Especially flow and pressure.

The pump needs to be matched to it's system. Only then can you determine things like flow, power etc. a4" 30m long pipe with no discharge pressure will have a very low frictional losses until the velocity rises to something very high which will wear your pipe out in days.

Please describe your system more clearly.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Slurry Pump

You do not seem to have a slurry pump curve attached to your above post.

If you do not spend time carefully examining every detail of your problem, you will fail ...

Examine the variable speed pump curve and the operating point noted here:

http://www.taspumpmonitor.co.za/technicaloverview....

MJCronin
Sr. Process Engineer

RE: Slurry Pump

(OP)
LittleInch
Flow rate is 50m^3/hrs
slurry is 4tonns/hrs that make 96 tonns per day
Yes it is a 4" pipe
discharge pressure is around 1.3 bars

RE: Slurry Pump

Think it would be a great idea to tell us what you want / trying to achieve.
Is this an existing installation or are you trying to design a new installation?
What ever it is, you have enough information to sort out what is a very basic slurry pumping installation.
You know the amount of product you need to pump in a given time, so everything else follows, the flow rate, the SG, the head calculations, the power calculations etc.
You're the intern, work it out and then ask for assistance to check your ideas.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: Slurry Pump

(OP)
I want to just propose an idea for increasing the efficiency of pumping, or change of pump which will give better output at lower power any thing that would benefit the company. but i stuck at calculation part. like i can only calculate the existing slurry velocity, settling velocity, and the required power. I am not getting how to compare it to what data and mathematically show that some changes can be made. that's where i need help.

RE: Slurry Pump

I'll take the part of your college supervisor here - 1st lesson, in your initial post was to tell what and why, what you wanted to do and why you wanted to do it. This would have saved people trying to squeeze information out of you - most of it of no value.
2nd, you say you know the velocity of the flow - no idea how you came up with this when in fact you would be better measuring the average flow rate over time of the slurry being pumped, you have the discharge pressure and you should be able to measure the power input, knowing these 3 values you could calculate the overall pump efficiency. Once this is established you could then think about ways of improving efficiency or if a pump change is necessary.
It's now up to you to do something to help yourself.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: Slurry Pump

Pump power is (Q x density x g x h) / efficiency

Where Q m3/sec
density kg/m3
g =9.81
h metres head of fluid
efficiency as a fraction (commonly 0.6 to 0.8)

My issue with your data is you now state the flow is 96 tonnes per day or 4 tonnes per hour

At 2.5 tonnes/m3 this is only 38.5 m3.

But your pump flow is stated at 50m/hr??

Therefore your pump operates for less than one hour per day or ??

I can only assume your 1.3 barg is at the discharge of the pipe at entry into your tank?

Do you need anything more?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Slurry Pump

(OP)
Thank You Artisi

RE: Slurry Pump

(OP)
LittleInch
slurry produced in whole day is 96 tonns
yes 1.3 bar is discharge pressure at the entry of the tank
50m^3/hr is the flow of slurry mixture including water and deposits
2.5 is SG of solid only

RE: Slurry Pump

Chaitanya;

Good information, now do the calculations, all info. for calculation has been given - so please let us know the outcome.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: Slurry Pump

Ok,

misunderstood - so what is your total volume of liquid slurry per day? 1200m3?

Then you can estimate an average density when you add your solid and work out your discharge head of the pump.

However your key missing bit of data is the pump curve for your particular pump, based on its impellor size and diameter and rpm.

If you can't find it, go look at the pump, find its serial number stamped on it then contact the vendor / manufacturer and they will probably be able to give you a copy if you ask nicely.

LI


Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Slurry Pump

The pump curve at this stage is not all that important, firstly the overall efficiency of the pump/motor unit needs calculating based on thru'put, head and power input, if it comes out as a ridiculously low number, then it might be worthwhile undertaking a pump review.
If flow for the application is fixed and density is acceptable, and the then the application duty doesn't change - a more efficient pump at the duty is the only consideration.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: Slurry Pump

MFJewell - your first attachment doesn't load (something wrong with the file name I think)

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Slurry Pump

(OP)
MFJewell
yes even i tried it keeps on loading and then shows a blank page.

RE: Slurry Pump

I know. It is stored on a flash drive at home. Will repost latter today.

RE: Slurry Pump

(OP)
I performed the calculations and as per them the required power to be provided is coming 40kW when efficiency is kept at 65%, whereas the power provided is 30kW. So here the pump can be changed for better output.
slurry velocity = 3.78m/s
slurry discharge = 0.03066m^3/s
slurry setteling velocity = 1.84m/s

These are my calculation results
and so according to me higher capacity pump must be provided with self priming pump to avoid choking.

RE: Slurry Pump

You are running round in circles, forget all the theory nonsense and look at the practical side of the installation.
Measure the flow rate, discharge head and power input to the motor as a start, from here you can start understanding what is going on and start making a few decisions in what to do next.
Flow rate to 5 decimal places and settling velocity doesn't help.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

RE: Slurry Pump

Please tell us what numbers you used in your calculation and where they came from (calculation or measurement.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

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