Slurry Pump

[Chaitanya Ojha]

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

 

[Chaitanya Ojha]

more like this one
sorry for the messy artwork.

 

[Chaitanya Ojha]

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

 

[Artisi]

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.)

 

[Chaitanya Ojha]

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.

 

[Artisi]

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.)

 

[LittleInch]

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.

 

[Chaitanya Ojha]

Thank You Artisi

 

[MFJewell]

Here is a L&L presentation I did for some coworkers many years ago. Maybe it will help.

 

[MFJewell]

Here is the FIPR spreadsheet.

 

[Chaitanya Ojha]

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

 

[Artisi]

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.)

 

[LittleInch]

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.

 

[Artisi]

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.)

 

[LittleInch]

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.

 

[Chaitanya Ojha]

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

 

[MFJewell]

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

 

[MFJewell]

Attempt 2.

 

[Chaitanya Ojha]

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.

 

[Artisi]

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.)

 

[LittleInch]

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.