Snowblower: Width vs PTO hp

[Jerry/MT]

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As it is that time of year again it will not hurt to talk about the speed of travel for a snow caster and its motive power.



The snow caster implement is totally dependent upon-

1. the implement carriers total horse power.
2. the rated horsepower of the power take off for the implement carrier
at the 540 or 1,000 RPM engine speed setting.
3. The rated gearbox horsepower rating for the snow caster implement..



I am familiar with the Chinook winds which batter Stevens Pass in The State of Washington, but I was not aware that they traveled as far inland as your location.


Being strictly dependent on temperature a fresh snow fall can weigh as little as 21 pounds per cubic foot and with freeze/thaw cycles the weight can more than double over time.

The two stage snow caster is totally dependent upon the impeller for its work as the the implement carrier is forcing the snow into the cross auger(s) which conveys the snow to the center of the snow caster where it is forced into the impeller housing strictly with the forward or reverse movement of the implement carrier.


The size of the impeller and the number of paddles in the impeller are what as Kenny Cartman would say "kicks A**" and is the business end of things.


Dependent upon the builder of the snow caster the impeller drum is dependent upon- 1., the number of impeller paddles and thier curvature within the impeller drum if applicable as a curved impeller reduces the amount of snow the snow caster can dispose of and 2., the rotation speed of the impeller at the 540 or 1,000
R.P.M., P.T.O., speed of the implement carrier at the rated engine speed of the for the Power Take Off in the front or rear but I will be using the 540 R.P.M., speed for reference.



In Pronovost's case(yes it is a shameless plug) their snow casters will have four or five or six impeller paddles and the impeller paddles are straight and slightly curved on the exterior edge and have been formed to create a cupping form to carry snow more efficiently to reduce spillage to a minimum(another shameless plug for Pronovost).


The larger the impeller drum in diameter and depth the greater amount of snow can be cast per rotation of the impeller paddles times either 540 or 1,000 revolutions.



Every snow caster will plug and shear pins if the implement carrier is traveling to fast!!!!!

If you travel at three miles per hour you are traveling at 264 feet per minute.
If you have one foot of snow to remove and the snow caster is 7 feet wide you have 147 pounds of snow entering the snow caster each second and 40,000 pounds per minute of snow (rounded higher) entering the impeller and the impeller must be running at its optimum speed(rated P.T.O., engine speed) to to cast the snow away. In the example the snow caster must have the torque to remove 667 pounds per second of the snow fall to keep up.


If you travel at one mile per hour ( I know, boring!!!!) you are only traveling at 88 feet per minute and requiring the snow caster to remove 13,000 pounds (rounded higher)(per minute of snowfall(big snooze, I know) The snow will be cast further and you will have no issues with snow banks. Just like fitting ground it takes time.

@ 21 lbs /cu ft, I get 647 lbs /sec = 38808 lb/min for 1 ft of depth and 7 ft across at 3mph.

 

[Klorinth]

Herringchoker,

You have answered the question I was about to ask... What is the effect of having an HST.

Seems to me that the infinite control of speed should allow a machine to handle more snow or a larger blower then a gear drive.

Am I wrong in my thinking?

If it is true that the HST can handle more in this case then the gear transmisson, then how much and how should you be running the tractor to ensure that it can handle it?

 

[leonz]

@ 21 lbs /cu ft, I get 647 lbs /sec = 38808 lb/min for 1 ft of depth and 7 ft across at 3mph.

I rounded higher for simplicitys sake. Are you in the Lignite coal portion of the Basin Jerry or near the Wyodak Coal Seam portion?



:thumbsup:




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Pronovost or not at all!!!:thumbsup::licking::drool:

 

[leonz]

Herringchoker,

You have answered the question I was about to ask... What is the effect of having an HST.

Seems to me that the infinite control of speed should allow a machine to handle more snow or a larger blower then a gear drive.

Am I wrong in my thinking?

If it is true that the HST can handle more in this case then the gear transmisson, then how much and how should you be running the tractor to ensure that it can handle it?

If its ok with you I will answer that as Herringchoker is off line.


The slower you travel with either transmission type the less shock loading you will have.


An automatic reversing transmission is more tolerant of shock loads but it does
not help much with a P.T.O., the shear pins are there to save the P.T.O., in case of overload. You need to keep the fan running high to pump the oil and power the fan to cool things.

The hydrostatic transmission will allow you to creep even slower to do the job
as less snow will be entering the cross auger housing.

You have to keep the tractors engine up at the P.T.O., engine setting for the mounted implement to work as the gearbox requires this much power to operate efficiently.



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Pronovost or not at all!!!:thumbsup::licking::drool:

 

[Klorinth]

So the HST might just give you a little more control and allow you to keep the RPMs up at an adequate level to handle the amount of snow entering the the blower...

Thank you.

 

[bruceha2000]

If you travel at one mile per hour ( I know, boring!!!!) you are only traveling at 88 feet per minute

Still a lot faster than a 24" shovel!

 

[leonz]

Yes Bruce, it is much faster than a shovel!!!!

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Pronovost or not at all!!!:thumbsup::licking::drool:

 

[D7E]

It will all depend on your location and the type of snow encountered. I would, however, forget a twin auger blower, your TC40 don't have the gonads. Twin augers are for tractors with 100 PTO horsepower on up.

84" rear mount 2 stage single auger and in light stuff (fluffy dry, cold snow, it barely works the tractor, however, busting 4 foot drifts of heavier stuff, it takes every bit of the 90 pto horsepower I have and I can bog the tractor down (and make it blow smoke) fairly easily and I'm turbocharged

What he said

 

[leonz]

So the HST might just give you a little more control and allow you to keep the RPMs up at an adequate level to handle the amount of snow entering the the blower...

Thank you.

Your welcome, The thing you must keep in mind is the impeller housing size as I mentioned earlier as the larger the impeller the less plugging AT NORMAL OPERATING SPEED dependent strictly upon snow depth and weight per cubic foot with relation to freeze thaw cycles which will add weight from melt and simple compaction as gravity and heavy snow fall are not your friend.


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EDIT: All this mess goes back to the cross auger(s) as the manufacturers are in no hurry to offer solid cross augers as standard equipment OR as an option except for the one or two dual auger models by Pronovost using a solid auger on the bottom ribbon/auger.
If they implemented a solid cross auger with narrow flighting the snow caster would work wonders and cast the snow a long distance

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_________________________________________________________________
Pronovost or not at all!!!:thumbsup::licking::drool:

 

[herringchoker]

Leonz, your explanation was well said. The HST is perfect for jobs such as snow casting, where you have to vary the ground speed to maintain a constant load on the PTO.

BTW, you would lose the wager on where the salt comes from. It used to come from Pugwash, but around here it now comes as a by-product of the potash mine in Penobsquis, N.B. I am about 60 miles northwest of Pugwash and 35 miles northeast of Penobsquis.

Aw, Leonz, planting mums! I just finished cleaning up and tilling the vegetable garden on Friday, which is the latest I've ever done it, what with the mild fall we've had here so far. But that's about to change, based on the latest weather forecast! Hope you get 'er done, sir. All the best! :thumbsup: