Irrigation System - Thai Made

[avocados]

Need help! I am looking for a local Thai producer of pipes and sprinkler for commercial farming (about 300 rai). Imported sprinklers and drip irrigations are way too expensive (transport and taxes, and margin paid to the distributers). Any recommendation would help. Thank you.

[rice555]

Hello avocados, the low price system parts are from Super Products, call them and ask them to send you if you are not close to BKK or Future Park where the two stores are. 02-939-6362-9 Their web site sucks. www.superproducts.co.th

If you are in Korat or Ubon, Do-Home has a very large selection of most everything in the catalog & the 2 SP stores.

Lot of local ag stores carry some of the same products and should be able to order for you, the one thing I do like from Arkel/Netafim is their disc filters, much more surface area than SP's of the same size.

If you are going to buy a lot, SP does have a 15% discount card, but the Do-Home

prices are the same, about -15% from the regular SP store prices.

I haven't been to the Ubon Do-Home store, so I'm not sure of they supply level. I live 10 minuets from the Korat store, they have free SP catalogs in store.

rice555

[avocados]

hi rice555,

thanks for your help! i will check them out asap.

rgds...

[rice555]

Hello avocados, if you are in LOS?, I would pick up a copy of House Agriculture Magazine, it has adds for most of the main irrigation oriented co's. Some carry some of the same products. I talk to a sale's person at S-P just a minute ago and she said they only do 15% for bulk.

There have been several co's that have started to run adds for drip products.

If you orchard uneven, you can't beat Netafim or Naan Dan PC sprinklers!

Netafims 'Spinnet' in great for nursery propagation.

rice555

[Maizefarmer]

Avocadas

Thats a fair old size to be irrigating! - do you have some idea of the piping/tube diameters you are looking for, and regards sprinklers - what sorts of flow rates (litres/p/min, gallons/p/hr) and throw radius you are looking for?

What crop type is this irrigation for?

Are you planning a set system, or a moveable type system?

Whats the water source? - dam/pond/canal/river ... whatever

Yes - imported equip will be expensive - but tubing/piping wise, there is no need to source imported stuff. I have always used localy produced pvc tubing (right up to 10" diameter) and found it to be plenty good enough (Thailand actually makes very good quality rigid pvc tubing and fittings).

Sprinklers - imported impact heads are indeed very pricy. My personal preferance over the years has been for Rainbird (USA) and Naan/Dan (Isreali). Sadly, my experiance of locally and Chinese made impact heads is not much to make a noise about. Over large areas Eastern made sprinklers never seem to give unifrom flow rates i.e. they have wild variation, one may flow x amount per hour, and the one next to it could be as much as x +/ - 30%. The castings are not bad, but the finishing and fittings are poor (plain bearings corrode, springs loose tension, washers never last ect ect ...) - so sprinkler wise, I am afraid you may well be best off in making the higher initial investment, and then not have to worry about constaly having to replace and/or repair.

I have good relationships with both the Naan and Rainbird franchise holders and will be happy to give you an intro if you wish in due course.

Pumps - plenty locally avalible components for whatever type of pump you intend to build - the eastern seaboard chemical plant/industrial scrap yards always have a large selection of pumps, and they are top class USA or European made pumps, but cost a fraction of the cost of new imported equivilants as the are used.

Ac motors (always the best choice where possible, irrespective of whether its a set or moveable system - as it costs around 30% less to pump with 3phase ac versus diesel), used pick-up/truck diesel engines (only option if its not s set system).

... and lastly: irrigation layout/planning for 300rai is a major project - I have layout software for the job, which calculates everything from radis's to pressure differentials over landgradients, spacings, flwo rates blah blah, blah blah .... get back to me if you get that far down the path and will be happy to help. Flow dynamics & Irrigation was my main Ag Engineering subject - would love to get stuck into a 300rai project (hint hint....)

Get back if I can help

[rice555]

Hello MF, I was assuming he was going to grow his 'name', on another forum he was looking for 3,000 seeds.

rice555

[Maizefarmer]

mmmmmm ............ I tend to agree with you - the way the question was posed indicated he had given little to no thought to the realities of irrigation on such a scale.

Oh well.....

[Somtham]

.......Ac motors (always the best choice where possible, irrespective of whether its a set or moveable system - as it costs around 30% less to pump with 3phase ac versus diesel), used pick-up/truck diesel engines (only option if its not s set system).

... and lastly: irrigation layout/planning for 300rai is a major project - I have layout software for the job, which calculates everything from radis's to pressure differentials over landgradients, spacings, flwo rates blah blah, blah blah .... get back to me if you get that far down the path and will be happy to help. Flow dynamics & Irrigation was my main Ag Engineering subject - would love to get stuck into a 300rai project (hint hint....)

Get back if I can help

Hey MF - how would you like to use that software to size a pump for me?

Water in bore hole is down 6m and I need to lift it another 2m. 40m of 4" pipe, 15m of 3" pipe, 3 - 4" 90 degree Els, 4 - 3" 90 Els, and 1 each 3" and 4" 45 degree fittings. What's the total head required by the pump and how many HP to deliver 25 cubic meters per hour?

Right now I'm using a 9 HP Kubota but want to switch to a 3 phase electric motor and pump combo.

thanks

[Maizefarmer]

Somtham

Something to tackle this evening after dinner, as opposed to watching BBC World Service- its a relatively striaght forward one -just one thing:

" 3 - 4" 90 degree Els, 4 - 3" 90 Els "- does this mean 3 x 4inch bends, plus and additional 4 x 3" bends - or is one or the other?

[Somtham]

Somtham

Something to tackle this evening after dinner, as opposed to watching BBC World Service- its a relatively striaght forward one -just one thing:

" 3 - 4" 90 degree Els, 4 - 3" 90 Els "- does this mean 3 x 4inch bends, plus and additional 4 x 3" bends - or is one or the other?

Ha, still waiting for my dinner...thom ka gai!!

I have a combination of 3" and 4" diameter pipes going to the ponds from the pump. In the longest run there are three 90 degree fittings with 4" pipe and another four 90 degree fittings with 3" pipe. These will add to the total head due to friction loss when the water needs to turn. Hope this helps with the calcs.

PS - don't like to drink (Chang) and post, but somethimes ya just gotta do it!!

rgds

[Lickey]

Somthan, my bore hole pump is 23 mtr down, it pumps uphill 320 mtrs on a 1 in 3 gradient, it will power 2 10mtr radi sprinklers, then the pipework goes down to the banana plantation, in total, 530mts, 2" pipe, and green hose for sprinklers, when you have pressure in the pipes, flowing bends make no difference, 90% bends are normal for water, right angles is another way to describe them.

My pump is a Franklin, it delivers about 1 litre in 3 seconds, its 230v 1 hp and 2 years ago was 12k bht,

Have a look at this site, http://www.mathews.co.uk/acatalog/Borehole_pumps.html there isnt much to compared to a 9hp kubuta delivery.

Cheers, Lickey.

[Somtham]

Somthan, my bore hole pump is 23 mtr down, it pumps uphill 320 mtrs on a 1 in 3 gradient, it will power 2 10mtr radi sprinklers, then the pipework goes down to the banana plantation, in total, 530mts, 2" pipe, and green hose for sprinklers, when you have pressure in the pipes, flowing bends make no difference, 90% bends are normal for water, right angles is another way to describe them.

My pump is a Franklin, it delivers about 1 litre in 3 seconds, its 230v 1 hp and 2 years ago was 12k bht,

Have a look at this site, http://www.mathews.co.uk/acatalog/Borehole_pumps.html there isnt much to compared to a 9hp kubuta delivery.

Cheers, Lickey.

Thanks Lickey. We have a Meyers/Franklin 1 HP pump probably similar to yours in the bore for the house water but I'm looking for a flow rate about 20 times higher than that pump will provide. The fittings, and even straight lengths of pipe, do make a difference by adding friction loss and require more head from the pump. Take a look at the Mathews website you posted and notice how the flow rate drops as the head increases. The pipe diameters, lengths, fittings, well depth, and height you're pumping the water to are all required to calculate the total head required of the pump.

Hopefully MF can stick those numbers in his software and pop out some specs for a pump.

Not sure I understand what you mean by this "there isnt much to compared to a 9hp kubuta delivery".

rgds

[Maizefarmer]

Somtham

Something to tackle this evening after dinner, as opposed to watching BBC World Service- its a relatively striaght forward one -just one thing:

" 3 - 4" 90 degree Els, 4 - 3" 90 Els "- does this mean 3 x 4inch bends, plus and additional 4 x 3" bends - or is one or the other?

Ha, still waiting for my dinner...thom ka gai!!

I have a combination of 3" and 4" diameter pipes going to the ponds from the pump. In the longest run there are three 90 degree fittings with 4" pipe and another four 90 degree fittings with 3" pipe. These will add to the total head due to friction loss when the water needs to turn. Hope this helps with the calcs.

PS - don't like to drink (Chang) and post, but somethimes ya just gotta do it!!

rgds

Yes - 90degree bends do significantly impact the power/fow equation - primarily by way of the turbulance they create.

Thats a fair amount of bends - there was no other way to route the tubing was there(?).

Where's the 3" tubing in this setup - is it the first section (s) of the length i.e. from the pump, and then followed by the 4" sections - or are the 4" diameter length(s) first, followed by the 3" diameter lengths?

I'll calculate the exact figure later on today (had a busy day), but off the top of my now sunburnt head(!), 25cubic meters through 3" and 4" tubing over 90meters with a 1 - 1,5bar head (roughly what I believe your pump needs to be able of for efficent flow - note: for efficent flow, not for flow to take place - their is a differance) shouldn;t require much power. The push through 3" tubing will be little, and through 4" tubing - well, 25kilo litres should run through tubing that wide with next to no power.

[Somtham]

Yes - 90degree bends do significantly impact the power/fow equation - primarily by way of the turbulance they create.

Thats a fair amount of bends - there was no other way to route the tubing was there(?).

Where's the 3" tubing in this setup - is it the first section (s) of the length i.e. from the pump, and then followed by the 4" sections - or are the 4" diameter length(s) first, followed by the 3" diameter lengths?

I'll calculate the exact figure later on today (had a busy day), but off the top of my now sunburnt head(!), 25cubic meters through 3" and 4" tubing over 90meters with a 1 - 1,5bar head (roughly what I believe your pump needs to be able of for efficent flow - note: for efficent flow, not for flow to take place - their is a differance) shouldn;t require much power. The push through 3" tubing will be little, and through 4" tubing - well, 25kilo litres should run through tubing that wide with next to no power.

Well. if I had to do it all over I would certainly change the pipe layout for the ponds and remove some of the 90's. Attached is a sketch that I hope makes sense. The 3" sections are actually at the beginning and end and the 4" section is in the middle of the run.

Thanks

[Maizefarmer]

Wowwww............!!!!!!!!!!! bet that was fun!

Yup certainly helps!

Thanx

[Lickey]

Somthan, the reason i endorsed the kubuta pump is that its the best for flood irrigation, not much good for pressure applications, if from what i understand from your diagram is you want to fill fish ponds?

2 or so years ago i renewed a lot of blue upvc piping on the farm, it had sunstoke and if i stood on it, it would break or crack, main runs have been replaced with black poly pipe, it will bend 90degree in 4 mtr, I tried to find 90 flowing bends with no luck for the blue pipe, only right angles,which i was informed by a water engineer made no difference to delivery whatsoever, Water and any kind of fluid will find the best and quickest exit avaiable.

Just an example, last week to make the cassava harvest easier, i removed the 2' pipe that waters the banana plants on the farside of the farm, as a temp suply i put 120mtrs of 1inch green plastic pipe to the 2" that goes round the banana plantation,i put 2 10mtr radi sprinklers on the main pipes and they both worked good,

Another time last year, the borehole pump would power 2 sprinklers at the top of the farm where the 2hp wouldnt, although the booster pump would power 4 big sprinklers at the lower end of the farm?? I really think its a matter of trying things out and stick with whats best for you,

Cheers, Lickey.

[slapout]

Lickey, Some people try to complicate/fix things that ain't broke. I think what the engineer told you although not 100 % correct is close enough for government work, its similar to squaring the id of pipe to calculate fluid volume to fill pipe, not 100% correct but works in field work. Turbulence is found in all fluid flow along surface of the pipe it is flowing through, thus producing fluid flowing at different flow rates (speed) within the pipe. Pipe size contributes to this as will any air or fluid of differing weight (muddy vs clean). It is referred to as, hold up, in fluid flow calculations. Like you said use the material on hand and find the best working system for what you want to accomplish with what you have. I put in a system, using 3 inch centrifugal pump powered by 5 hp gas engine, drawing water from 5 meter via 3 inch pipe, discharge thru 3 inch which is 200 meter in length. This is swedged down to 1 inch via on/off valve with sprinkler head set at each tree over 12 rai. I can water 280 +- trees (24 at a time) on the 12 rai in a day and the Thai say its 2 or 3 day job. Again its just a matter of using what they have available, knowing what you want to accomplish and doing it.

[Maizefarmer]

Somtham - theoreticaly I get just under 7hp, practicaly that figure jumps to between 9 - 16hp.

The theoretical figure ignores many issues that are user/application specific - and will be unique to your cirucmstances (touched on below), the practical figure(s) includes things like the diameters and bends you have given, but more importantly the big variable in the practical figure comes from: pump type and its efficiency.

This calculation really needs to be done with choice of pump type in mind, and it's flow chart - and in your case the decision that first has to be made is: are you going to place the pump in the hole (submersible), or are you going to place the pump at ground level.

Multi-stage submersible is always more efficient (from a power perspective, but maybe not from other perspectives like maintenance for example, and capital outlay), but another factor now comes into play - is the bore diameter large enough to accomodate the pump required, can you have sufficient single phase amperage on your ac supply to power a +/-15 pump (actually, you really need 3phase to do the job properly else you are going to need close on 20hp because ac motor effieicency now comes into play!) - but that aside (ground level or submersible ignored) ac is always more efficient from a running cost perspective than having to use diesel (about 30% moe efficient)....

... and on and on we can go - these are never striaght forward calculations, and while I can look at it from a pure hp requirement, this is not neccessarily the best/most efficient or most ideal way of pumping in your case, as it ignores a whole bunch of practical issues that should be considered when planning.

So - are we any closer to identifying the ideal pump power requirement? Well, I'll put it this way: if you use a submersible you'll get away with between 7 - 10 hp, if you use a ground level centrifugal (and thats almost certainly the pump type it will be - centrifugal), you'll get away with something between 8 - 16hp (depending on how well the impellar characteristics are matched to rpm).

And that lastly, please note - this is power consumed, not neccessarily the power rating stamped on the pump name plate!

[Somtham]

Thanks for your time MF. The bore is only 4 inch diameter so I will be looking for a centrifugal 3 phase.

rgds

[Maizefarmer]

er ........ bore is 4"! - is that lined or un-lined?

First thing you need to do is get that up to 6" at least, preferably 10" or 12" - then, as its only a few meters deep, get a large diameter tube lining pushed down.

3phase - yes, but only if you have it already - for those volumes I can't see it making much economic sense gettng 3phase installed - it costs quite a bit. Other wise stick with single phase - it'll still be cheaper over the long run than diesel.

[Somtham]

er ........ bore is 4"! - is that lined or un-lined?

First thing you need to do is get that up to 6" at least, preferably 10" or 12" - then, as its only a few meters deep, get a large diameter tube lining pushed down.

3phase - yes, but only if you have it already - for those volumes I can't see it making much economic sense gettng 3phase installed - it costs quite a bit. Other wise stick with single phase - it'll still be cheaper over the long run than diesel.

Yep, 4" PVC lined. The bore is 16m deep and the water rises to 5-6m from the surface. The guy hand drilled it and 4" was the largest spade drill he had. He's actually drilled 3 bores for me and they're all about the same. 0-7m mostly sand, 7-10m beautiful bentonite (wish that was up at the surface), 10-14m more sand, and 14-16m granite(?), and then water. I don't think making the bore larger is an option at this time.

The 3 phase is already there so no issues with a 3 phase 380v pump system. It's gotta be cheaper, less maintenance, easier, and definately more quiet!!

rgds

[avocados]

thanks for your input. been spending alot of time last few months sorting out the logistics. will be going with the pressure compensating drip C 8L/H , along with PE tubing, 20mm sublines, 63mm main line for the first 50 rai (8 hectare). will be sourcing these products from Products Super. got in touch with Naan and Netafim, whose products look superior but they come with a price. anyway, at Products Super, they got two young technical guys who's been helpful in working out the pressure, flow rate etc... as for the pump and generator, the hardest part has been trying to secure a converted car engine (isuzu truck engine) that can link to a generator & pump as currently i got no electricity. will start to grow the first 600 avocado trees next month, and the next 2400 trees by next March. seems like the nursuries in pak chong & royal project in chiangmai hence can only do maximum 3000 trees per year; hence it will take around 3-5 years before all 300 rai are all planted. alternatively, am also considering growing these trees from seedlings and graft the cultivars in my nursery. but that would require experts in grafting techniques. saw videos and live demos in pak chong and the success rate are around 50% for these experts. hopefully i can duplicate their success rate.

Avocadas

Thats a fair old size to be irrigating! - do you have some idea of the piping/tube diameters you are looking for, and regards sprinklers - what sorts of flow rates (litres/p/min, gallons/p/hr) and throw radius you are looking for?

What crop type is this irrigation for?

Are you planning a set system, or a moveable type system?

Whats the water source? - dam/pond/canal/river ... whatever

Yes - imported equip will be expensive - but tubing/piping wise, there is no need to source imported stuff. I have always used localy produced pvc tubing (right up to 10" diameter) and found it to be plenty good enough (Thailand actually makes very good quality rigid pvc tubing and fittings).

Sprinklers - imported impact heads are indeed very pricy. My personal preferance over the years has been for Rainbird (USA) and Naan/Dan (Isreali). Sadly, my experiance of locally and Chinese made impact heads is not much to make a noise about. Over large areas Eastern made sprinklers never seem to give unifrom flow rates i.e. they have wild variation, one may flow x amount per hour, and the one next to it could be as much as x +/ - 30%. The castings are not bad, but the finishing and fittings are poor (plain bearings corrode, springs loose tension, washers never last ect ect ...) - so sprinkler wise, I am afraid you may well be best off in making the higher initial investment, and then not have to worry about constaly having to replace and/or repair.

I have good relationships with both the Naan and Rainbird franchise holders and will be happy to give you an intro if you wish in due course.

Pumps - plenty locally avalible components for whatever type of pump you intend to build - the eastern seaboard chemical plant/industrial scrap yards always have a large selection of pumps, and they are top class USA or European made pumps, but cost a fraction of the cost of new imported equivilants as the are used.

Ac motors (always the best choice where possible, irrespective of whether its a set or moveable system - as it costs around 30% less to pump with 3phase ac versus diesel), used pick-up/truck diesel engines (only option if its not s set system).

... and lastly: irrigation layout/planning for 300rai is a major project - I have layout software for the job, which calculates everything from radis's to pressure differentials over landgradients, spacings, flwo rates blah blah, blah blah .... get back to me if you get that far down the path and will be happy to help. Flow dynamics & Irrigation was my main Ag Engineering subject - would love to get stuck into a 300rai project (hint hint....)

Get back if I can help

[Maizefarmer]

Well for what it worth, as you may already know, hydraulics/fluid dynamics was/is my subject within the overall context of my agricultural engneering studies - a fancy term for a "farm plumber". Over the last 12 years or so I've been employed on occassion as an independant irrigation consultant by several SEA (South East Asian) state bodies on public ag projects, blah blah, blah blah .......

In addition, I run and have a rather decent engineering workshop - although primarily for farm equipment maintenence, frabricating single/3 phase and diesel ag pump systems, is often undertaken - to ISO* and SAE standards if required (god forbid!) i.e. pump setups which need to adhere to some or other enviromental, ferrous/non-ferrous or noise limit - or to whatever other standard(s) need to be accomodated or are applicable.

From design & conception onwards, thru to component selection & sourcing, thru to fabrication, installation and commissioning - can all be handled "in-house" - in sizes/volumes up to around 450m3 - 500 m3. The bit I have to call 3rd parties in for is actual certification (re; the blue star mark in para 2 - I can't do ISO certs - I have to send the hardware off to "someone else" for any ISO cert) , and any 3phase/480VAC wiring work/inspection and grid connection work - I can do the install and setup of pumps, but connection, transformer, wiring, boardwork, safety aspects and other related aspects have to be signed off-by a certified sparky - which I am not, and do not have the qualifications for.

In short: I would be happy to undertake the pump side of this project for you.

That aside all that, let me share with you some points you should keep in mind and think through when it comes to implementation of your irrigation plan(s). It's a bit of a mouthful, but I hope gets both the point, and the importance, across in one go:

Your primary drive is going to based around a used Scania/Isuzu/Nissan/Volvo or similar 12 - 15 litre 6 pot diesel truck engine, driving a centifugal pump (?) PS - I can supply new Kirloskar centrifugal pumps at as good a price as anyone else in Thailand. The engine/pump connection - suitably sized flexi-coupling of sorts (it's neigh on impossible to line the engine output shaft on an engine this size to the impellar shaft accurately enough to use a solid connection). Yes … for the land area you are talking about (50 rai thru to 300 plus) you are going to require a couple of diesel driven pumps - with your primary drive been based around something in the region of 350hp – 500hp (truck engine).

I have a used Scania 320hp block (which is out of a high mileage 1994, 6x4 department of forestry truck which was rolled down a hill!). This is already frame mounted (see frame size info further on) - but whatever hp is required, and whatever truck/brand name engine you prefer, there's seldom much problem sourcing used engines in Thailand - no shortage of blocks and spares, though from a reliability point of view keep in mind that most "stand-alone" blocks come out of trucks that have been invloved in some or other end-of-life RTA, or have just been driven into the ground. In the former case, you can on occassion get an engine that requires little to no work, but trucks that have been driven till their deaths' - these usualy usualy have engines that will need to be stripped down and rebuilt (otherwise it becomes a never ending process of part repair & replacment hile in pump service - which ='s constant downtime.

If I supply a block I usualy pass it on with a garuntee of sorts (i.e. it will have beeen stripped and rebuilt before been used in a pump or gennie setup - so I know the condition). If the customer supplies the block, unless otherwise agreed/stated (subject to any work I may be asked to do on the engine) there is no garuntee offered on this part of the overall engine/pump setup.

The boxframe base can be ¼” plated top & bottom, and hence serve as the diesel fuel tank (with the length/breadth/4” of the box-frame determining the “fuel tank” volume – somewhere around 400 – 600litres). Its style/set-up I like to use as it both re-inforces and increases the rigidity of the frame, while keeping the fuel load out of the way.

The pump chosen can be new or used. Subject to the pump size/type, a good look around the Eastern seasboard industrial scrapyards can often turn up superb examples of European brand name pumps - nearly all of which are scrapped from some or other process plant on expansion or close down - and if you're lucky, you can find them still mounted to a frame, and more rarely (but not impossible) also with their original engine. In any case, it will be specifically chosen to give the required water volume/pressure output for direct drive @ the engine’s max fuel efficiency on the rpm/torque graph.

This is a VERY important aspect of the whole setup - get the calc's here wrong by as little as a few percent, and you will be f'ckd down the line, to put it bluntly.

.... right, sales talk and trumpet blowing done - now the important part of these notes - forget all the above, but remember the rest.

The above could also be setup to produce the required flow/pressure at max engine power on the graph, or at max torque, or at most efficient rpm … however you want it set-up, but my experience is that you will require water flow/pressure to be produced with the engine graph as close to the torque/ fuel efficiency cross over point as possible. Makes sense - no "magic" here, just plain old common sense.

This could, oddly enough, sometimes mean choosing a pump capable of producing [significantly] more flow/pressure than is required, and/or running the pump at a point on its flow/pressure graph that one would not expect to run it at.

The point about the preceeding 3 paragraphs I wish to convey, avocados is this: irrepspective of who undertakes, or helps you with the choice/fabrication and setup, it is the important to get this side of the equation bang on - an approximation is not good enough - if your "consultant" cannot offer you a set of fuel consumption figures for given flow rates and given pressures, and contractualy agree them with you as a highlighted or seperate item over and above the general "good for purpose" type contract, then go find another engineer. Why? - because the land area(s) you are talking about irrigating are going to require substantial energy (VAC or diesel) consumption/costs - so much so that your profit/loss margins are going to revolve to a large degree around this one cost factor alone, let alone anything else.

........mmmmmm - trade tricks about efficient agriculture pumping - I'll do myself out of a job if I'm not careful here. Actually, there's no "black magic" in all this, but you'd be suprized just how often I see and come across large scale irrigation projects which are not "good for purpose" - because the irrigation set-up (although it may be delivering plenty sufficient H2o) has not been designed with in service running costs in mind. My guess is that (in Thailand, Cambodia, Laos) around 7 out 10 (at least (?)) large scale ag irrigation pump-sets and irrigation layouts I have sen, or looked at, are not designed properly with the above in mind, and do not run near as efficiently as they could.

Where do I see the most common error made?

Here - interperatation of the flow/pressure graph: for most (nearly all) large centrifugal type ag pumps max effciency usualy falls around 3600rpm (with 2400 - 2600rpm, alot less common and with far less choices avalible, but none-the-less, can be found).

So -whats the problem?

The problem arises when set-up and fabricated into an engine/pump frame mounted combo, driven off a diesel engine. Most diesel truck engines run at best efficiency around 1600 - 1800rpm (and in the case of many modern truck & tractor engines the figure can be even lower - down to around 1200 - 1300rpm). So what, just set up a 2:1 gearing reduction ratio. Nope, its not as easy as that may sound, or look - when you come to dealing with power outputs in the range of 300 - 500hp the extra mechanics to match these ratio's often introduces a bunch of cost & reliability issues that most folk prefer to avoid, and in many cases can actualy be demonstrated to offer little , if any, advantage (theres a fair loss in torque transfer across a belt & pulley reduction gearbox rated for 300 - 500hp, and machining up a paif of standard involute gears, along with a suitable sealed wet bath will add a fair cost to the project at these power ratings!)

I'm a great believer in direct drive, and believe me, my preference for going to the effort of "mix & match" so that the direct drive philosophy can be adhered to get the right result, has on more than one occassion (many in fact) proved to be the correct solution in the long run - not only from an initial capital outlay perspective, but also long term running cost(s), as well as maiantence costs, and last but not least also in reducing later upgrade/change over to accomodate any expansion irrigation requirements.

Remember this when calculating energy costs to run your diesel driven pump: diesel engines consume power according to kilowatts produced.

If you have a 300hp engine chewing say 195grams p/kw/hr and your pump only needs say 200hp, it's not impossible to run that 300hp engine at whatever rate is required to produce only that 200hp, and to be able to run it so that it consumes no more fuel than a 200hp output engine would consume if that was used instead. The "magic" lies in sourcing a 300hp engine which can be run in direct drive mode, to produce the required 200hp output only, and consuming no less/no more than 195grams p/kw/hr - in other words an engine which will direct drive the pump at the point on its (i.e. the pump) graph for the best/required flow/pressure efficiency. Get this right and things like fuel consumption, maintenance, long term reliability, can actually land up costing far less, despite running the engine below its rated output (less stress), or what it may have cost if the pump was driven with say a 200hp rated diesel engine.

This same approach can be applied to pump choice i.e. a good understanding of pumps can often enable choice of a pump rated for say 30m3 p/min, to run at say 23,5m3 p/min (sometimes by way in inflow restriction, sometimes by way increasing NPSH, sometimes by way of changing the impeller - usually the diameter on balanced doubled-face type impellers) - to improve overall efficiency. This could happen because of restrictions the client has regards engine choice (i.e often when they have an engine they want used because they do not or cannot afford to purchase another engine).

Been able to implement these sorts of considerations effectively requires careful study, understanding, and an ability to interperate both engine & pump performance parameters versus respective energy requirments, and then been able to impement the theory.

The whole idea: to get required waterflow/pressure for the least energy input cost.

I'd be interested to know just what the guys at Star may have discussed with you regards pump/engine setup along the above lines - if at all(?)

Although I give them 9/10 for product knowledge, when I asked them to run spreadsheet type clac's for me (and we are talking about an ag project going back to around 2003/2004 – the last time I had dealings with them), I wasn't best impressed with their “pump man’s” figures when it came to required power calc's & respective energy costs for a number of different engine/pump combo's. When it came to "mix 'n match" type engine/pump combo's as I have described in above paragraph's, to better flow/pressure form a given set-up, and/or reduce energy costs for given flow/pressure ocmbinations - the fellow was out of his depth. In all fairness to him there is no imperical formulae (although you certainly need to know them) - it comes down to been able to interpertate and apply the figures.

I don’t know how serious you are about all this avocados, but if you are setting up an ag irrigation project this size, you are going to be throwing some serious money into it. Do not under-estimate the importance of getting the pump/power part of the equation worked out accurately. This is going to be a major factor on your balance sheet every quarter. Get it wrong by just a few percent – and your margin could vanish in the blink of an eye.

This project of yours is not some "market garden" irrigation exercise, this is a serious irrigation project - get it right and get right first time round.

If you want to take the discussion with me further - lets keep the tech side of it on the open forum so all may benefit from my comments (or, indeed correct me when/where wrong, so that others can offer ideas and comment - not often an irrigation project this size is undertaken by an ex-pat in Thailand)

Any business type question (if you want to) we can discuss thru the PM-private message facility) - if you decide to move forward through some other party, by all means still feel free to ask questions - costs nothing and may help to provide info/points to consider for others who may be thinking of big irrigation.

Right - 'nuff said, I've gone on enough (I go on a bit when it comes to engineering talk) - justget this one right.else I see you having running costs that will quickly over-run any "best priced" bargin offer you may be encoruraged to take up.

Wish you all the best.

MF

Edited November 9, 2009 by Maizefarmer

[Dpolenz]

Well for what it worth, as you may already know, hydraulics/fluid dynamics was/is my subject within the overall context of my agricultural engneering studies - a fancy term for a "farm plumber". Over the last 12 years or so I've been employed on occassion as an independant irrigation consultant by several SEA (South East Asian) state bodies on public ag projects, blah blah, blah blah .......

In addition, I run and have a rather decent engineering workshop - although primarily for farm equipment maintenence, frabricating single/3 phase and diesel ag pump systems, is often undertaken - to ISO* and SAE standards if required (god forbid!) i.e. pump setups which need to adhere to some or other enviromental, ferrous/non-ferrous or noise limit - or to whatever other standard(s) need to be accomodated or are applicable.

From design & conception onwards, thru to component selection & sourcing, thru to fabrication, installation and commissioning - can all be handled "in-house" - in sizes/volumes up to around 450m3 - 500 m3. The bit I have to call 3rd parties in for is actual certification (re; the blue star mark in para 2 - I can't do ISO certs - I have to send the hardware off to "someone else" for any ISO cert) , and any 3phase/480VAC wiring work/inspection and grid connection work - I can do the install and setup of pumps, but connection, transformer, wiring, boardwork, safety aspects and other related aspects have to be signed off-by a certified sparky - which I am not, and do not have the qualifications for.

In short: I would be happy to undertake the pump side of this project for you.

That aside all that, let me share with you some points you should keep in mind and think through when it comes to implementation of your irrigation plan(s). It's a bit of a mouthful, but I hope gets both the point, and the importance, across in one go:

Your primary drive is going to based around a used Scania/Isuzu/Nissan/Volvo or similar 12 - 15 litre 6 pot diesel truck engine, driving a centifugal pump (?) PS - I can supply new Kirloskar centrifugal pumps at as good a price as anyone else in Thailand. The engine/pump connection - suitably sized flexi-coupling of sorts (it's neigh on impossible to line the engine output shaft on an engine this size to the impellar shaft accurately enough to use a solid connection). Yes … for the land area you are talking about (50 rai thru to 300 plus) you are going to require a couple of diesel driven pumps - with your primary drive been based around something in the region of 350hp – 500hp (truck engine).

I have a used Scania 320hp block (which is out of a high mileage 1994, 6x4 department of forestry truck which was rolled down a hill!). This is already frame mounted (see frame size info further on) - but whatever hp is required, and whatever truck/brand name engine you prefer, there's seldom much problem sourcing used engines in Thailand - no shortage of blocks and spares, though from a reliability point of view keep in mind that most "stand-alone" blocks come out of trucks that have been invloved in some or other end-of-life RTA, or have just been driven into the ground. In the former case, you can on occassion get an engine that requires little to no work, but trucks that have been driven till their deaths' - these usualy usualy have engines that will need to be stripped down and rebuilt (otherwise it becomes a never ending process of part repair & replacment hile in pump service - which ='s constant downtime.

If I supply a block I usualy pass it on with a garuntee of sorts (i.e. it will have beeen stripped and rebuilt before been used in a pump or gennie setup - so I know the condition). If the customer supplies the block, unless otherwise agreed/stated (subject to any work I may be asked to do on the engine) there is no garuntee offered on this part of the overall engine/pump setup.

The boxframe base can be ¼" plated top & bottom, and hence serve as the diesel fuel tank (with the length/breadth/4" of the box-frame determining the "fuel tank" volume – somewhere around 400 – 600litres). Its style/set-up I like to use as it both re-inforces and increases the rigidity of the frame, while keeping the fuel load out of the way.

The pump chosen can be new or used. Subject to the pump size/type, a good look around the Eastern seasboard industrial scrapyards can often turn up superb examples of European brand name pumps - nearly all of which are scrapped from some or other process plant on expansion or close down - and if you're lucky, you can find them still mounted to a frame, and more rarely (but not impossible) also with their original engine. In any case, it will be specifically chosen to give the required water volume/pressure output for direct drive @ the engine's max fuel efficiency on the rpm/torque graph.

This is a VERY important aspect of the whole setup - get the calc's here wrong by as little as a few percent, and you will be f'ckd down the line, to put it bluntly.

.... right, sales talk and trumpet blowing done - now the important part of these notes - forget all the above, but remember the rest.

The above could also be setup to produce the required flow/pressure at max engine power on the graph, or at max torque, or at most efficient rpm … however you want it set-up, but my experience is that you will require water flow/pressure to be produced with the engine graph as close to the torque/ fuel efficiency cross over point as possible. Makes sense - no "magic" here, just plain old common sense.

This could, oddly enough, sometimes mean choosing a pump capable of producing [significantly] more flow/pressure than is required, and/or running the pump at a point on its flow/pressure graph that one would not expect to run it at.

The point about the preceeding 3 paragraphs I wish to convey, avocados is this: irrepspective of who undertakes, or helps you with the choice/fabrication and setup, it is the important to get this side of the equation bang on - an approximation is not good enough - if your "consultant" cannot offer you a set of fuel consumption figures for given flow rates and given pressures, and contractualy agree them with you as a highlighted or seperate item over and above the general "good for purpose" type contract, then go find another engineer. Why? - because the land area(s) you are talking about irrigating are going to require substantial energy (VAC or diesel) consumption/costs - so much so that your profit/loss margins are going to revolve to a large degree around this one cost factor alone, let alone anything else.

........mmmmmm - trade tricks about efficient agriculture pumping - I'll do myself out of a job if I'm not careful here. Actually, there's no "black magic" in all this, but you'd be suprized just how often I see and come across large scale irrigation projects which are not "good for purpose" - because the irrigation set-up (although it may be delivering plenty sufficient H2o) has not been designed with in service running costs in mind. My guess is that (in Thailand, Cambodia, Laos) around 7 out 10 (at least (?)) large scale ag irrigation pump-sets and irrigation layouts I have sen, or looked at, are not designed properly with the above in mind, and do not run near as efficiently as they could.

Where do I see the most common error made?

Here - interperatation of the flow/pressure graph: for most (nearly all) large centrifugal type ag pumps max effciency usualy falls around 3600rpm (with 2400 - 2600rpm, alot less common and with far less choices avalible, but none-the-less, can be found).

So -whats the problem?

The problem arises when set-up and fabricated into an engine/pump frame mounted combo, driven off a diesel engine. Most diesel truck engines run at best efficiency around 1600 - 1800rpm (and in the case of many modern truck & tractor engines the figure can be even lower - down to around 1200 - 1300rpm). So what, just set up a 2:1 gearing reduction ratio. Nope, its not as easy as that may sound, or look - when you come to dealing with power outputs in the range of 300 - 500hp the extra mechanics to match these ratio's often introduces a bunch of cost & reliability issues that most folk prefer to avoid, and in many cases can actualy be demonstrated to offer little , if any, advantage (theres a fair loss in torque transfer across a belt & pulley reduction gearbox rated for 300 - 500hp, and machining up a paif of standard involute gears, along with a suitable sealed wet bath will add a fair cost to the project at these power ratings!)

I'm a great believer in direct drive, and believe me, my preference for going to the effort of "mix & match" so that the direct drive philosophy can be adhered to get the right result, has on more than one occassion (many in fact) proved to be the correct solution in the long run - not only from an initial capital outlay perspective, but also long term running cost(s), as well as maiantence costs, and last but not least also in reducing later upgrade/change over to accomodate any expansion irrigation requirements.

Remember this when calculating energy costs to run your diesel driven pump: diesel engines consume power according to kilowatts produced.

If you have a 300hp engine chewing say 195grams p/kw/hr and your pump only needs say 200hp, it's not impossible to run that 300hp engine at whatever rate is required to produce only that 200hp, and to be able to run it so that it consumes no more fuel than a 200hp output engine would consume if that was used instead. The "magic" lies in sourcing a 300hp engine which can be run in direct drive mode, to produce the required 200hp output only, and consuming no less/no more than 195grams p/kw/hr - in other words an engine which will direct drive the pump at the point on its (i.e. the pump) graph for the best/required flow/pressure efficiency. Get this right and things like fuel consumption, maintenance, long term reliability, can actually land up costing far less, despite running the engine below its rated output (less stress), or what it may have cost if the pump was driven with say a 200hp rated diesel engine.

This same approach can be applied to pump choice i.e. a good understanding of pumps can often enable choice of a pump rated for say 30m3 p/min, to run at say 23,5m3 p/min (sometimes by way in inflow restriction, sometimes by way increasing NPSH, sometimes by way of changing the impeller - usually the diameter on balanced doubled-face type impellers) - to improve overall efficiency. This could happen because of restrictions the client has regards engine choice (i.e often when they have an engine they want used because they do not or cannot afford to purchase another engine).

Been able to implement these sorts of considerations effectively requires careful study, understanding, and an ability to interperate both engine & pump performance parameters versus respective energy requirments, and then been able to impement the theory.

The whole idea: to get required waterflow/pressure for the least energy input cost.

I'd be interested to know just what the guys at Star may have discussed with you regards pump/engine setup along the above lines - if at all(?)

Although I give them 9/10 for product knowledge, when I asked them to run spreadsheet type clac's for me (and we are talking about an ag project going back to around 2003/2004 – the last time I had dealings with them), I wasn't best impressed with their "pump man's" figures when it came to required power calc's & respective energy costs for a number of different engine/pump combo's. When it came to "mix 'n match" type engine/pump combo's as I have described in above paragraph's, to better flow/pressure form a given set-up, and/or reduce energy costs for given flow/pressure ocmbinations - the fellow was out of his depth. In all fairness to him there is no imperical formulae (although you certainly need to know them) - it comes down to been able to interpertate and apply the figures.

I don't know how serious you are about all this avocados, but if you are setting up an ag irrigation project this size, you are going to be throwing some serious money into it. Do not under-estimate the importance of getting the pump/power part of the equation worked out accurately. This is going to be a major factor on your balance sheet every quarter. Get it wrong by just a few percent – and your margin could vanish in the blink of an eye.

This project of yours is not some "market garden" irrigation exercise, this is a serious irrigation project - get it right and get right first time round.

If you want to take the discussion with me further - lets keep the tech side of it on the open forum so all may benefit from my comments (or, indeed correct me when/where wrong, so that others can offer ideas and comment - not often an irrigation project this size is undertaken by an ex-pat in Thailand)

Any business type question (if you want to) we can discuss thru the PM-private message facility) - if you decide to move forward through some other party, by all means still feel free to ask questions - costs nothing and may help to provide info/points to consider for others who may be thinking of big irrigation.

Right - 'nuff said, I've gone on enough (I go on a bit when it comes to engineering talk) - justget this one right.else I see you having running costs that will quickly over-run any "best priced" bargin offer you may be encoruraged to take up.

Wish you all the best.

MF

good post,very long though.

[Maizefarmer]

Fair enough - it's called thinking ahead: cover all the issues/questions that folk inevitably haven't thought through (if they haven't been there done that before), or come back and ask about in a never ending stream of subsequent questions and postings. You know its coming - best get it done with. The other way of looking at it is to leave it out - if they are serious about the job, they'll come back and ask (they need to), if they don't then I've saved myself the time.