A simple weight reduction tactic - or fixing what ain't broke?

[wft2800]

Saw this on BBC News and wondered what you'd all make of it. Replacing concrete ballast on front-loaderes with a water ballast tank, to be filled on installation? Good idea or asking for trouble?

Device could make washing machines lighter and greener

Most washing machines come with 25kg of concrete - but researchers claim there's a simple alternative.

www.bbc.co.uk

 

[mralex]

I saw that this morning too..

I'm just thinking.. Wouldn't the water get kind of slimy and disgusting in there?

 

[foraloysius]

I saw it on Facebook. The specific weight of concrete is much higher than the specfic weight (gravity) of water. So you would need a much bigger tank to hold the water than the size of the concrete weight.

 

[tomturbomatic]

In old Westinghouse washers, the weights were cast iron and they were able to form it into a complete ring around the front of the tub, but then they changed to cheaper concrete. The machines were not as stable because the concrete was not as dense as the iron so density is important. 

 

[vacerator]

Been going on for years now.

GE also used a concrete block and cable to balance their top loaders.
With tubs, baskets, etc. being lighter, balancing can be done centrifugally, and with springs and hydraulic shock absorbers. Of course, we have seen some modern washers destruct in high spin speeds.

 

[rolls_rapide]

Done before!

I think it has indeed been done before - in the form of the "Reason" washing machine, which has been in stasis for yonks now.

Look at this link. Scroll halfway down the page, and you will see their ballast tanks.

http://https//www.kickstarter.com/projects/1045993408/reason-washing-machine-in-a-class-of-its-own

 

[rolls_rapide]

Looking at the tank retrofitted to that Indesit on the BBC page, that tank sits too proud of the machine. They'll have to redesign their suspension/tub assemblies to accommodate the water tanks.

Might as well start again with a new design.

 

[henene4]

There is a huge probem with the way Reason did this though: Weights mounted to the tub will reduce the sway of tub it self. If the tanks just sit in the bottom of the machine, the cabinet won't move, the tub and drum however will.

Furthermore: For things like washing machines, weight dosen't really affect the cost of shipping much. The density of such a machine as a whole isn't really all that big:

A standard EU machine is 60cm*60cm*85cm=306000cm³. That is 306l.
A machine weighs about, let's say 100kg.
That means, it's only about 1/3 the density of water.

For shipping of such items, volume is far more significant. The only people who really care about weight are the end consumers, who by now - for the most part - get them set up anyways.

 

[wft2800]

I think the weight concern is more about reducing fuel usage in transportation and thus the all-important carbon footprint...

 

[rolls_rapide]

"the weight concern... reducing fuel usage"

I agree with that. It is surely more economical to transport a lorry load of lighter machines than the same load of heavier machines.

 

[henene4]

Big picture

Sure, transportation carbon foorprint would be smaller.

Do most people worry about that when they buy a machine? No, they don't.

That system would mean big and thus expensive engeneering changes, reduced drum sizes and probably liability issues for verry little gain for the company.

 

[rolls_rapide]

Yes, they will.

Especially when powerful polluting vehicles are being outlawed, and being replaced by under-powered 'Eco' ones instead.

Then it'll be a case of endeavouring to lighten the load wherever and however possible, and that means everything across the board.

 

[henene4]

That's a timeframe of 30+ years. The lifecycle of a washer design is generally 20 years or less, for the most part.

In 30 years we alread might be past the singularity...

 

[panthera]

This solution is used for

everything from concrete to pancake mixes to paint so I can see the desire to attempt it - we're talking about a lot of mass, here.
I'm not an engineer, but my feeling is that their proposed solutions are, even with very intelligent circuitry, just not going to do what they want them to do.

As for the water 'spoiling', lots of ways around that one. They could even have the machine fill and drain every time it's used...which would, of course, defeat the whole 'eco' aspect of the thing. If my suspicions are proved right, though, first seriously unbalanced load at spin and this machine will take care of the longevity problem by self-destructing, anyway.

 

[warmsecondrinse]

I heard this on BBC World Service yesterday; what I heard might've been different from what you all have read. The designers seemed to be framing their project as a work-in-progress with promising initial results and by no means an end product. The main idea seemed to be the energy savings from transport of a lighter product and greater ease of installation. Using water instead of concrete would in effect allow the counterweights to be installed AFTER the machine was in place.

"That system would mean big and thus expensive engeneering changes, reduced drum sizes..."

Right. Such changes have their own CO2 footprint in that people consume resources while formulating the changes and then factories have to be rejiggered. Regardless of how small a footprint the changes might have, they need to be figured in. Also, reduced drum sizes mean a greater number of loads.

"The specific weight of concrete is much higher than the specfic weight (gravity) of water."

This was acknowledged in the article I heard. The designers seemed to believe they would eventually be able to compensate for that.

It'll be interesting to see if they get anywhere with this.

Jim

 

[splittub]

Yet another example of eco-hysteria leading to quality reduction.

 

[rolls_rapide]

They'll probably design the tub and counterweight tanks in such a way, that they'll pop in the drum and seal the whole lot up.

Then, when it comes to replacing one single component - no can do. You'll probably have to buy the complete unit: drum + tub + counterweight complete.

And they'll have to have more hosepipes to fill the tanks and drain them. Software will have to be written to prevent the machine's operation if the tanks are empty.

 

[tomturbomatic]

The WP-built 29" combos used water to balance the load via the three ballast tanks in the drum. I believe the ZUG does that now. The drum in the combo did not have much in the way of suspension separate from the machine except for the flexing of the machine frame which actuated the balancing process. I would hope that the ZUG has a simpler balance system, but these two machines, which use water to dynamically balance the spinning drum, use the weight of the water most efficiently to reduce the cause of the forces that need to be controlled.

 

[vacerator]

Those 29 inch Whirlpool

and Kenmore combos were awesome. Many owners were upset when parts became obsolete for them. My dad used to repair them. He told me they also had an air compressor.