Your not going to find anything. Or and the most find it easy.

most information on this are empirical and intellectual property information

Where did you look?

There are someting like a billion hits when searching for helical conveyors.

Why not take another look. This time, really look.

1. HELICAL/SPIRAL CONVEYORS - HOME PAGE OF ELEKTROMAG

1. Flexible screw conveyors for bulk materials handling are ...
   

1. Nedpack vertical covneyor compared with spiral conveyors
   

1. Spiral Conveyor - Belt Conveyors, Roller Conveyors, Gravity ...

lyn, he's looking for calculations to build?

And having designed and built grinders, I already see issues his going to have......

Lodging being one of them

I know what he wants. he's not going to find it here. If he searches long enough he can find plenty of examples and probably calculations for them.

I don't think he's looked much yet. But, you know me, Mr. Pessimist.

Always with the negative waves. Moriarty.

'Kelly's Heros'

Excellent!

Here's another source you might try. Worked great for me when I was designing a feed system for a midwest pasta plant. There's tech info in there.

http://www.helixtech.com.au/

How does it handle straw in a barrel?

The pic is just an example, the link below it is for a design software program....ed. note

Thanks to all for your quick response!

"Your not going to find anything. most information on this are empirical and intellectual property information"

@phoenix:There should be such information on earth for an engineer to start designing something! I won't give up on this!

@lyn: As phoenix said I'm looking for calculations... The links you provided are just a little description about conveyors...

@RDGRNR: That site you introduced, seems to be a simple company site... I didn't find any engineering info or calculations on it! Can you please be more specific about this?

@Solareagle: "Helix conveyor" software isn't related to helice in anyway! Helix is the name of the company! And that software can only design belt conveyors!

"How does it handle straw in a barrel?"

@lyn: I want something to force the material into a pipe exactly like meat grinder which forces meat into small openings . It has 2 advantages:

1. Compression and force

2. Conveying ability

Thank you all again

I'm looking forward to your answers

Well,

I'm speechless.

You need one of these.

Auger - Wikipedia, the free encyclopedia
Shakes head.

Yes!

Auger is another name for it!

But how to design it?

The diameter, pitch, length, material used for making, etc ARE needed!

Well,

I've got a pill you can take.

It will infuse you with all the knowledge you need to design any system you could ever conceive.

PM me with an address you can be billed at.

The cost is $18,908.00USD.

Come on! Don't be so greedy!

I just found something nice:

http://www.saimh.co.za/beltcon/beltcon11/beltcon1114.htm

This is exactly what I need:

http://www.waghelaindustries.com/pressure-taperwarm.html

I'm sure I'll find it.....

There ya go! Keep looking. it's there somewhere.

Well how about an actual straw grinder?

http://www.alibaba.com/showroom/straw-grinder.html

http://www.sietronics.com.au/millsveg.html

Feed that into a screw extruder....

remember, the design can change with each product. Because each product has different physical properties.

kpax7,

There should be such information on earth for an engineer to start designing something! I won't give up on this!

I'll tell you what I did. I had designed and built one and put it through a number of experiments and did reverse engineering calculations, such stress, force force the screws would be pushing, ect....

This was almost 20 years ago, I had search initially with no luck, things may have changed since then, good luck,

So the conveyor is the solution to some problem you have...what exactly is the problem you are trying to solve?

@lyn: Thanks, I hope so!

@Solareagle: Again they're just commercial websites with no info... And actually they are Straw choppers ... I just wanted to point out the helice by saying grinder at the first place to simplify the understanding!!! But thanks for the idea...

@phoenix911: Thanks, but 20 years ago .... is just a little old! It's now information era!

@Tom consulting: Thanks for response... I described the problem in my previous post... Calculations for designing a helice is required which is used to convoy and press the straw into a pipe with lower diameter than the helice cylinder ...

Thanks again

20 years ago, Thats when I started, and one thing hasn't changed in the 20 years, the information you seek, still hides in public written form.

Its something I can't explain where you would understand, Screws weren't invented last night. I still wish you the best.

And I'll push you in the direction, look at the rotary or axial flow combines. Its not the answer, but it will demonstrate what you don't know ^{(you don't know what you don't know is evident here)} . Keep an open mind, this technology over 30 years old. You may learn something.

Thank you so much... I know.... But I don't know why!

And I've thought of combines already ... But they're just convoying helices and elevators in the combine (the radius is the same along the helice so they make no pressure on the convoyed material) and plus that finding the calculations for them is hard too... :-)

I wish good luck for you too...

and plus that finding the calculations for them is hard too

That is what I'm trying to tell you, emperical information.

And emperical information no one makes money publishing it, they make money by applying it.

And emperical information does not meet your 'now' standards.

Don't scorn a gift, I will point you in the direction, but that's all, emperical information is earned.

What size straw length will you be using........... if you have shorter stems say 3-6" works differently that longer stems. And I'm not even addressing chaff. It will have to be standardized.

Take a look at some of these.

CONVEYOR HANDBOOK
1. Similar
2. Conveyor Design GuidelinesCached - SimilarUndo...
   
3. Conveyor Design Procedure , Conveyor design guideCached - SimilarUndo
   
4. APPLICATION DESIGN MANUAL Undo- Quick View
   
5. Conveyor Design Guide 101410x

Martin gear always had excelent info on auger conveyors

Why not just feed it to cows and run it through an extruder?

This waste pyrolysis plant in Moscow uses a helical conveyer which pushes the feed through a pipe. Seems to be what you want to do with straw and other agricultural materials. Abrasion was an issue they dealt with by special high-alloy steel.

Thank you all for the effort .... I'll check your posts and inform you soon...

Regards

Dear kpax7,

I worked for a while in chemical and semichemical pulp production plants, being involved in pilot and industrial tests using several kinds of different straw to produce raw paste for paper manufacturing. Materials like wheat, rye, rice, soy, hemp, wineshots, corn, cotton linters, bagasse, and some others.

Not an engineer, so I can not guide you with calculus, but with some knowledge of the issues arisen, and the solutions applied, also in the screw conveying systems used throughout the process.

As some of the above posters said, among many other details, the exact definition of the raw material to be processed is key.

Type (a loong way from wheat to rye, not to mention rice, physical properties), sizing (mesh sizing!) prior to feeding, moisture (KEY!), etc...

Were the fed material not controlled accurately, or calculations done "for the best" only, you could end with a bunch of broken or bent shafts, couplings, undersized drive trains, burnt belts,etc...

The picture from Solar Eagle shows (commonly known as a twin screw press, we used them at intermediate stages) and some other like Pandia digesters single screw feeders, (a bit too much may be), both are designed usually to extract liquid impregnated in the material fed.

If you intend to force trough a pipe, it seems the target is some kind of ¿briquettes?.

What is your target volume reduction?

Let us know.

Best regards,

Abel

I want to talk more about my idea in my mind:

This screw should be 25-30 inches maximum in length and 15-20 max in width. And must be able to run with Tractor's PTO power (For example 81.96 hp [61.1 kW]) And I can decide to feed wet or dry material and in what size....

@phoenix: It's just an idea for now (for making a machine to get straw and push them into soil). So I haven't decided on the straw size yet...

Plus that, I couldn't come up with a better mechanism to push the straw into a pipe.. Can you give me a better mechanism to do this? (for constant feeding)

And I didn't understand... What is "Martin gear"?

@lyn: Your links are all about belt conveyor... Still tanx for search and effort...

@Solareagle: Feeding the straw to cows is not an option !!

@Willmot: That's good to know how to overcome the abrasion. Thanks a lot

@ablmeh: Thanks for participation. Your valuable information is important for this project...

Which takes less power? Dry or wet material? Because from one aspect, moist straw is more flexible and can be pressed more easily.... Still I can't guess....

Excuse me for the quick drawing with paint!!

Martin Gear is a company : www.martinsprocket.com

At one time they had quite a bit of info.

With the information you supplied, I would suggest something with a postive displacement. Constant feeding is going to be difficult.

I understand somewhat the requirement, I would lean towards wet material. have you tried looking at manure pumps and as well as feild applicators (injectors).

Positive displacement won't allow the machine to press the material into the pipe... All the straw will go back through the cylinder and will cause accumulation problems...

But that site had very nice info on it... No calculus but good hints on design methods.

Thank you so much for sharing your information...

Dear kpax7,

Some quick notes before go to sleep.

As you mention, you want to feed wet or dry material, and in different sizes.

Calculating for the worst (longer material and wet) the sizing of the elements will increase seriously.

-Even with the proper screw, the straw will not move so easily to be compressed.

-For transportation (not compression), with 10% moisture, we use max 60% volume load in the screw conveyor, estimating density of 30kg/m3 during transport. D=600mm. L straw:50mm.

-Differential between the friction of the straw with the pipe wall and with the surface of the screw, will tell you if the material goes forward being compressed or just has a happy trip in the screw, plugging it completely.

-You will need energy to achieve a certain density at the end.

This energy will be mainly used cutting the straw to a certain size, and after compressing it.

The more you cut at the beginning, the closer you are to the targeted density.

If you, let us say, do not cut the straw at all, the energy used to compress it will increase. Quite. And the cost of the machine to do it.

Of this two options, cutting makes the material more "workable".

The smaller the size of the material, the better. Longer pieces tend to make ropes.

And those ropes and build-ups, are stronger than... a hammer mill rotor of 300kg with 72 hammers spinning at 3000rpm with a 250kw motor behind.

With a proper designed machine, the problem is solved in less than 20min. Not proper design=pile of scrap metal.

With higher water content, the straw is more compresible, but also increases friction.

Prevent a torque limiter (spring coupling or so) to protect the machine.

Enough manholes or easily removable sections to remove plugs.

Possibility of reverse rotation will save lots of work. If implemented, ensure the back of the screw allows the material a way to go out.

Check no metal to metal contact generate a hot spot. Straw is flammable.

Maybe you have already considered most of this points, if not, happy to give a hint.

Now, some questions:

What is the intended production? 200kg/h or 20t/h?

How will you feed the straw in the system?

Have you considered a ""piston pump"" (note the double brackets) model for this job instead of screw? (this just come to my mind as more easy, but it probably haves another bunch of considerations and problems as well)

Salu2 cordiales,

Abel

Wonderful! Your Experience and Info in this field helped me a lot....

So I limit my input material to "Very low moisture" and "4-5 mm size" and I should remember not to load the machine more than 40-50%. I'll put a friction clutch before the gear box of the helice. That will do the job. I never thought about Manholes(!) Thanks for the idea! Reverse rotation is very helpful but requires more calculations and design which is not needed for now (maybe later)

Is that "Differential between the friction of the straw with the pipe wall and with the surface of the screw" calculable?

What is the intended production? 200kg/h or 20t/h? Actually there's no production! The compressed material will be buried somehow (!) through the pipe....

And the feed system is unknown for now... But I'll work on it...

And for the piston pump, Isn't it for fluids?! Never saw any pump for solid material!

Best regards, wishes and thanks

Kpax7

kpax7, we'll give you a push in the right direction but you should follow through on the push, an example from my post #32 on Manure Pump.

This is just one of many manufactures.

If you don't follow through, you don't learn.

Dear kpax7:

Moisture: Straw properly stored, (depending on the climate on your area and harvesting conditions) it can be found to be below 15% without problems.

"4-5mm size": this, in straw terms, it is almost dust. You will need a big amount of energy to mill straw this size!!! Do you really need it?.

Friction calculation: Yes it is calculable, but not, I am not able to do it.

Production: Yes, there is production!! Calculate the voids....

How many holes______

what size_______,

do you want to fill with straw at what density?_________

Do you have straw at hand?, take a 20l bucket, fill it with straw compressing it by hand and feet as required. ( is it harder than you thought?).

Does it looks like what you want? What is the weight of the straw in the bucket now?

How long time do you think it should take to fill say... 10 holes?______

Thanks for the follow up

15% moisture is good

I actually meant to write 4-5 CM and ....

And I'm not able to calculate the friction either ....

The machine has only one output pipe with around 5-6 cm in diameter.

The output density is Not important. The only important factor is the fluent and smooth movement of stuff through the pipe...

And about the time: As this machine should work on farms and has a continuous input feed, and the end of the pipe is open so .... Material comes from one end and goes out from the other end.

Dear kpax7:

As per your data:

40-50mm straw length.

50-60mm outlet pipe.

It seems not a good relation of sizes for a "fluent and smooth movement trough the pipe", unless you push it with something, in a quite short lenght of pipe. Not to mention curves or elbows (are there?)

Friction, with density and pressure will increase.

First put all the data together:

-define the raw material characteristics. (we will not guess it!!)

-define the target: what you want to put, where you want to put it, and a what speed (weight x volume x time). Yes, we are speaking about production! How long do you think is a reasonable time to fill one hole??

Phoenix911 is absolutely right about the empirical procedure for this systems, when no detailed literature is available..

Moreover if the application it is not meant to be of industrial size (as it seems here).

As much as people here can try to push you in the right direction (this means help, not do it for you), empirical means the use of your hands and eyes and, trough observation and sweat, reach your own conclusions.

This is the way when calculus is not possible /accesible.

Even if the results are not what you expected, you will have learned something in the way.

I would suggest you a little (well, medium) exercise:

-Take a pipe as the one you mention (i.e.: d60mm, L= 1000mm) with a cover at the bottom that can be easily opened. (6 holes d4mm at 60º, three old electrodes trough)

-Fix it in vertical position, at some distance from the floor, to allow the material go when you open the bottom cover.

-Check the density, moisture (15% is ok?)and size of the material at hand.

-Fill the pipe by hand with the intended material, without pressing it. How much can you put? Goes down smoothly?.

-Use another pipe that can be inserted inside the previous one to compact the straw.

(Remember the ""piston pump""?) Without push!. Let it rest smoothly on the straw, not leaving it fall,only by its own weigth. Leave it for a fixed amount of time (i.e:15secs)

-With the weight of the pipe used, and the reduction in volume obtained. At least you will end with a pressure (force/surface) that throws some reduction in volume.

-Without removing the bar, open the bottom cover. Does the material "flow"? Does it looks like you expected?

-Try fill the pipe again with new straw, changing the weight of the pushing pipe (fill it with sand, or something similar?).

-Collect data.

-Repeat changing only one parameter at a time. Your choices.

Excel will make great graphics with the results, and the values obtained will be more accurate than most of the calculus you can find around. Mostly, because they are not done with your raw material, and you will not need extrapolate from others.

Let us know how it goes.

Salu2 cordiales,

Abel

Thank you all...

I'm working on it...

I'm testing all available ideas

During the design process, you might also want to consider these conveyor maintenance best-practices.

@phoenix: Tanx for the push... I'm glad having such experienced ones beside me

@Bin95: Thanks for sharing your info