TANK CLEANING -ALFA LAVAL SPRAY JET

USEFUL FORMULAS

Some useful formulas for pump users

BHP( KW) : 0.163 x m3/min x head ( m ) x sg / efficiency ( % )
This is will indicate the BHP in Kw


Velocity ( m/sec )= Q ( M3 /HR ) X 353.60 / D2 ( pipe diameter in mm )

Recommcneded velocity
Suction Line : 0.5 to 1.2 m/sec
Discharge Line : 1 to 3 m/sec

Option : the lower the better , however it is piping cost versus power consumption
over a long term period .Greater saving on power if motor is bigger

see earlier posting on this issue

PUMPS REVIEW

1) ALFA LAVAL SOLID C
- very solid looking material and nice finishing
- can be mounted to IEC standard Foot Flanged motor
- one set of mechanical seal for all ranges of Solid C- low invertory cost
-Front loading shaft seal design ,the seal can be changed in minutes without removing the backplate
- complies with 3 A. CE and with EHEDG certification
- simple competitive and yet good operating life,only maintenance kit is one pcs of casing O ring and a set of mechanical seal

Suction Under Vacuum

attn : Mr Ang

Under such pumping condition , workout the NPSH available in the system and get pump with
lower NPSH required .It should be lower than NPSH avaialable otherwise the pump is not going to work

For this application ,it is under 10 m bar which is almost 98 % vacuum .
therefore 10 meter x 98% is = 9.8 meter
NPSHA = 10 METER - (scution pressure + vapour pressure ) = 0.2 M
NPSH AVAILABLE IS 0.2 METER
Vacuum ejector is mostly use for this particluar installation(palm oil refinery )
The suction head loss and vapour pressure for above is not taken into consideration
as it is negligible

VIBRATION - CAUSES AND EFFECTS

Vibration can cuased serious effects to pumps as well as other rotating equipment

The causes of vibration can be due to mechanical or hydraulic reasons



Mechanical fault

a) most common is unbalanced impeller .shafts . worn out impeller or even coupling
it is quite common for maintenance personel to change damaged bearings
and put the pump running

b) worn out bearings

c) misalignment of pump and driver

d) Pipe strained

e) mass of pump being too small

f) loose screws on pump mounting or baseplate

g) bent shaft

HYDRAULIC REASON

a) cavitation

b) air in the system ,leak or vortexing

c) too high speed of pump

EFFECTS
a) damages of mechanical seal and the life of mechseal is directly related to the
shaft movement
b) bearings and other pump components

Give A Pump 6 to 10 bar?

Again , we still recieving enquiries with this requirement of 6 to 10 bar
The operating pressure should be known and specified ,not max pressure

For such specification, pump suppliers will clarify with you or based on 10 bar as operating pressure . If the operating head is only 6 bar ,then you would have bought an excessively oversized pump. paying more for a bigger pump and paying more for running cost in term
of higher motor kw .

Also sometime flowrate ,given as 100 to 200 lpm

AN EXPLODED VIEW OF ROBUSCHI RBS ROOT BLOWER

MAXIMUM WORKING PRESSURE AND TEST PRESSURE

There is some misunderstanding of maximum working pressure and test pressure among some pump users
a) DIN 24255 pump do specify Maximum Hyrdostatic Test Pressure of 24 bar , note this is test
pressure done hydrostatically and not operating condition

b) Maximum Working Pressure at 16 bar at maximum speed of 3600 rpm ( 60 hz 2 pole )
In Malaysia ,it is 50 hz 2 pole ,which is 2900 rpm

Therefore .again specify the operating head rather than maximum 16 bar as what we
encounter this morning

Customer wants a pump maximum 16 bar but for circulating purpose only which we reckon that then system head to be only about 3 bar or 30 M
And flow . 350 m3/hr at 16 bar ?

Big motor kw is required for this duty

Verticle Sump Pump Mounted on Poontoon in the Effluent Pond at a Palm Oil Mill
This pump serve as disludging pump and as an aereator

PUMPING IN CORROSIVE ENVIROMENT

In most cases , we tend look at pump material of construction when come to handling of corrosive pumping media and this usually cause no problem if the materials are compatible to the media to be pumped

However the construction material of drive components like geared unit or motor is often ignored .If the pump media are store in open tank , evaporation takes place rendering
the working area to be full of acidic fumes .These fumes will then corrode the gear nox or motor
which usually in cast iron construction . You almost never come across motor with SS body ,right ?

Solution

a) get the work area well ventilated
b) coating of the Gear unit and motor with proper coating
c) choose a motor that is Aluminum body , plastic fan cover and plastic
terminal box

These will surely extend the life of it and lower the maintenance

A customer in Gemas has been paying good attention in this issue and I am glad
to hear one of the pump has been able to last

SUBMERSIBLE PUMPS -MAINTENANCE

As these pumps are submerged all the time, most of us tend to overlook the maintenace of it
Most failures are detected only when the pump stops pumping and by then , maintenace cost will be high as the seal leaked and electric motor got burnt , bearings damaged and motor stator
could also be damaged

It is highly recommended that preventive maintenance be carried out seriously . mechanical seals and bearings replaced as schedule.This will save pump from unnecessary damages

While Submersible pumps are easy to istalled and save space , it is sometime to costly to
maintain compared to end suction or self priming pumps

Verticle sump pump will be another option and very little maintenance are needed
However ,the pump is usually costly

MAXIMUM PRESSURE?

Do Not specify Head as Maximum 16 bar

Specify the Operating Pressure

Pump Manufacturer may specify Maximum Working pressure as 16 bar on the catalogue
but it does not mean that the pump can operate with a discharge pressure of 16 bar

A pump with a discharge pressure of 8 bar and 16 bar .makes a huge difference in term
of Pump Size & the Motor KW

As I had always mentioned if you are not sure of the Discharge Head ,check the Guages of existing unit or Calculate

Also .when you increase flow for the same diameter of pipeline,the discharge head increases as well
For Bulking Installation ,pumping for factories to Ship the pipeline is usually quite long ,
and this is make a huge difference in pumping head

Suction Line is equally important , as pumps are located at Pumping Station a distant away
from the Tank Farm .When level in the tank drop ,the NPSH avialable is the system will also
drop . Cavitation will take place .One way of ditecting is looking at the running ampheres

VELOCITY IN PUMPING

For new pumps and piping projects , especially for high viscous products it is necessary to
working out the velocity of flow before deciding on the pipe size (most will straight away decide on the pipe size )
The ideal velocity for discharge line should be between 1 to 3 meter per second
and suction between 0.5 to 1.5 Meter /sec

Higher velocity means smaller pipe being used ,thus higher head loss and this mean pump
operates at higher pressure , and higher head means higher Kw of drive or bigger size of pump

On the cost factor , the piping cost will be lower but power cost will be higher
Work out total cost of piping for different size and compare with power cost and see the saving achieveable
This is applicable to high capacity pumping rate . small pumps will not affect much

Suction line is usually more critical .There is one bulking plant where suction line diameter
is to small and pump located far away from tankyard , all these resulted in extremley low NPSH
avialable , at 0.20 meter . Any upgrading of pump is not possible to achieve the required capacity as any pump will be operate in cavitating condition . Replacing the suction line system will cost a bomb .

Looking at this comparison , a pump operating at 9 bar and another at 6 bar

model : 200-500 -------------------------200-500
capacity : 450 m3/hr at 9 bar ------------450 m3/hr at 6 bar
motor Kw : 150 Kw ----------------------95 Kw


See the huge difference in motor kw ( 60% )?

Understanding of Sanitary And Stainless Steel Products

Again ,we came across another established Company using Sanitary Pipes ,SS storage tanks
for milk related products as raw material BUT....Cast Iron Gear Pumps and something is really
wrong here

Also .some Ball Valves used non sanitary but Standard industrial valves
Looks like there is a mixed up or ignorant

When we talk about sanitary pumps in food industry , we talk about cleanability which means how thoroughly the pump can be clean manually or CIP.And there are few levels of cleanability
for each requirement.Pharmaceutical will require the highest

And not just the pump being shining or looks clean


Management plays a very important part , as most tend to be overly conscious about cost
and the Engineering department may have difficulty in explaining between the product and
price .The mindset is always " go for the cheapest " in most SMEs and engineering department
is always under pressure to go for the lowest

CENTRIFUGAL AND PD PUMPS FOR MILK AND MILK PRODUCTS

With the China Milk Products contamination, which is extremely serious ,it is high time we look
at Compliance seriously

Contaminations can come from raw material , production and even equipment used in the
production .There are various established International Standard and Guidelines. some of which are as follow

3-A This standard has the purpose of establishing and documenting the material ,
fabrication and installation (where appropriate) requirements for the engineering
design and technical construction files for all porducts ,assemblies and sub-assemblies
supplied by the manufacturer .The manufacturer has to be in compliance with the
sanitary criteria found in 3 -A Sanitary Standards pr 3-A Accepted Practice , which is
for dairy and food processing equipment

ALL ALFA LAVAL PUMPS RANGES CONFORM TO THIS 3-A STANDARD

FDA The Food and Drug Administration(FDA) in the USA is the enforcement agency of the
US Goverment for food ,drug and cosmetics manufacturing
All The manufacturer of food ,drug and cosmetics in the USA are required to that
products are safe

USDA The United States Department of Agriculture (USA ) primarily responsible for
regulating biotechnology in the United States

EHEGDG European Hygenic Equipment Design Group was formed in the European
Community to promote hygiene during processing and packaging of
food products



Hope the Malaysian Food Manufacturers will be more aware of the such requirements
and more importantly the desire to Hygenic Operation
However ,very rarely we find manufacturer mentioning of any compliance requirement
for the intended purchase of the equipments /pumps . Seem that the only concern is
what is the lowest price , compliance disregarded

Upgrading Pumping Capacity with Present Piping System

Today ,there is a customer with pump Model 65/32 at 1450 rpm ,the rating is 42 m3/hr at 35 M head.
He wants a bigger pump of 150 m3/hr at ?(mentioned maybe about 8 bar ).A pump supplier will
surely be safer to offer this rating .right ? After all the pump supplier is not bearing the
energy cost

Again, it is rather difficult to find Engineer that would work out the System Head before
deciding to upgrade

If we estimate at 8 bar ,the pump size will be much bigger and motor probably be 75 Kw
and if we estimate at 5.8 bar ,the motor of 45 Kw is sufficient

In this case ,it may be necessary to upgrade the pipe diameter and operate at about 4 bar
you will enjoy considerable energy cost as 30 kw motor is sufficient with pump of 80/20

The Engineer should work out the Piping Upgrading cost versus Energy consumption

All we need to do is go back to Basic ,that is back to reference book

Many many of us still do not read enough ,agree ?

Pump Pressure Not Enough ( SEREMBAN JOB )

This is another common issue
A contractor called and inform that pressure not enough , when earlier given was

a) Given
Capacity : 20 m3/hr at 42 m Head ( 4.2 Bar )
Pump Speed : approx 2100 rpm( slurry pumps )

b) Offered pump with same operating parameter and
same operating speed

c) later called and say need to operate at 6 bar

d) This is an indication that the user is not aware or not knowing what is his
requirement , which is 6 bar

e) what can be done

1) as pump is belt driven . adjust the pulley diameter to the required speed
and with reference to pump curve , there has been cases of people guessing the
speed and do many changes before arriving at the required speed and head

2) the motor 15 hp was designed for working pressure of 4 .2 bar at 2150 rpm
therefore the motor has to be upgraded to the required BHP ( 18.5 kw ) .Again ,remember
to refer pump curve

Above is a very simple issue , but the first thing that come to the user's mind

" hey . your pump lousy man , can only reach 4 bar "

" your motor too small lah ..that is why cannot reach 6 bar ''

What is being highlighted here is that . if the User knew what he wanted and
size the pump correctly . there is no waste of time doing further modification which
also incur additional cost,,,

Specifying Pump Head or Discharge Pressure

This has always been an issue all the while .Users tend to give pump head without actually determining the correct discharge head .For convenient purpose ,we will assume the head as
correct and this often leads to problems like motor tripping etc

What will happen ?
When the actual system head is 30 M instead of 60 M , the pump will be operating on the
extreme right of the curve ,maximum flow and low head ( 140 m3/hr at 30 m instead of
90 m3/hr at 60 M)

The result
a) 90 m3/hr at 60 M, the BHP is approx 40 Hp
b) 140 m3/hr at 30 M , the BHP is 55 HP

For the case ,you can either trim the impeller to smaller diameter
or Throttle the discharge valve ( never throttle the suction line )

This pump is open Impeller Slurry pump and supplied with 60 Hp motor 2900 rpm
A 40 hp could be used if the head is 30 M ( 90 m3/hr at 30 M

Take note the power difference

It must be emphasize that giving the actual operating head is extremely important
much saving can be made from

a) smaller pump being used
b) Pump can operate at 1450 rpm instead of 2900 rpm if head is low ,lower wear& tear
c) smaller motor Kw and in long run energy saving
d) long term lower maintenance cost for smaller pumps

Pump Certification

There are various certification for pumps and and equipment
As an example

ATEX
a) Some Plant may require ATEX Certification from Europe and these are pumps are not
common .The prices can be extremely high and delivery is also very long period
EBSRAY PD pumps can be supplied with ATEX, details fo Atex can be obtained from the websites


b) Bomba (Malaysia )
For Fire Fighting application ,pumps supplied must be under the BOMBA approved list
and EBSRAY Streamline Series is under Bomba Approved List

c) Lloyd'S REGISTER QUALITY ASSURANCE

Allen Gwyness pumps are certified under Lloyd's Quality Management System

And there are many others Standard of requirement say API for Oil and Gas users

Food or Pharmaceutical Companies may require Traceability Certifcate by manufacturers
Our Alfa Laval Pumps does come with this on request and chargeable

I will continue to update on this Topic

Memahami "Pressure ' dari Segi Halangan

Pressure adakala tidak mudah difahami dari aspek praktical bagi kebanyakan jurutera . Dalam sistem Piping . ia lebih mudah dipandang dari segi Halangan atau"resistance " .Bermakna . piping yang lebih kecil mempunyai halangan(resistance ) yang lebih tinggi iaitu dikenali sebagai ' " higher head loss in piping "

Pressure dalam Pumping , biasa di kenali sebagai " Head "
1 bar =10 M head atau 14,5 psi

Pressure Tidak Mencukupi

Sebelum membuat keputusan untuk mendapatkan pam baru ,kerana pam yang sedia ada tidak dapat memberi pressure yang perlu , apakah sebab sebabnya?
A) WEAR AND TEAR
B ) ATAU SYSTEM PRESSURE TERLALU TINGGI
C) ATAU PAM DI BELI,TIDAK MEMENUH SPECIFIKASI
D) ATAU SYSTEM PROBLEm



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