滚筒洗衣机甩干不如波伦的吗？[求助]

luojs

发现，滚筒如果感觉不平衡/震动比较大的话，会自动降低转速。而且降低的值是线性可变的，还算比较智能。不过确实比较鬼。

黑妹

最初由 废言 发表
[B]内桶直径不同，它的角速度是不是一样呢？ [/B]

转速与角速度是等价的。如果转速相同，内筒直径大，离心力也大。滚筒洗衣机的内筒通常大于波轮洗衣机，如果脱水转速与波轮相同的话，离心力应该更大，甩得更干才对啊。

strongc

可能达不到标称转速吧

mazda609

这是一个美国人的滚筒试验报告,可以参考。

I finally got around to running some detailed spin tests in my AEG.
For this series, rather than 10 lbs. of regular cottons, I decided to use around 6 lbs. of fluffy absorbent bath towels. This will of course (presumably anyway) result in a higher RMC at any given spin speed, but should serve to clearly illustrate the differences in spin effectiveness of various rpms... and it was a lot easier to work with 5 bath towels, than a big pile of T-shirts, etc!
I should pause here, to mention the "Official Testing Procedure For Clothes Washers", as it pertains to RMC. If you check out this pdf file:
http://www.eren.doe.gov/building ... ule/clwshr_rule.pdf
you can see some detailed calculations and tables on the subject, down toward the end of the document. Note that the column headers on the main RMC table on p.3332 are mixed up - you can see the correct headers in the "sample table" immediately preceding. In short, a higher rpm gives a lower RMC... as does a longer spin... as does a warm rinse. And while you rapidly get diminishing returns with ever-higher spin speeds, moving up to 500+ gravities of spin does in fact make a significant difference...
To measure fabric weights, I used a digital kitchen scale, with a resolution of 0.1 oz. During my tests, I repeated each measurement at least twice, nearly always getting the same result, and always getting readings within 0.1 oz. Unfortunately, this particular scale has a max capacity of 80 oz., so I had to divide up each batch of towels into multiple weighings. I was concerned that this might introduce additional error into the data, but as described below, I took measurements several different ways, and found the results to be highly consistent.
First, to get a baseline, "dry" weight of these towels. The five towels used for this experiment were clean and dry, sitting in a bedroom closet. Five bath towels, as I mentioned. They are a mixture of sizes, although all are "full size" bath towels. All are at least a year old, so there&#39s now very little linting in a given wash cycle (i.e. the "new towel shedding phase" has passed, LOL), and yet they&#39re in good condition, nicely absorbent, with no fraying or significant wear.
I placed the towels on the scale in two groups, first 3 and then the other 2, to get under the 80 oz. limit. Got a total weight of 62.5 + 36.6 = 99.1 oz. Wanting to verify the accuracy of this scale and the overall technique, I re-grouped the towels and weighed again (remember these are all slightly different sizes): got a total weight of 57.9 + 41.2 = 99.1 oz. So far, so good!
Now, as is mentioned in that pdf document, it&#39s important to get the truly "bone dry" fabric weight, and not include any residual humidity absorbed by the towels in storage. At the moment, Southern California weather is dominated by "June gloom" high-humidity conditions much of the time (I measured around 60% humidity in my living room yesterday). And of course these towels were stored near a bathroom, where it would be easy to gain an extra few percent RMC.
So, into the Lavatherm 57700 dryer, on a 40 minute timed dry program. Took them out, and found a total weight of 59.8 + 36.2 = 96.0 oz. Verified as 60.6 + 35.4 = 96.0 oz. Checked the small amount of lint trapped on the lint filter, and found it to register as 0.0 oz., below measurable limits. So apparently 96.0 oz. is the true "dry weight" here (I didn&#39t plan on using exactly six pounds, although it&#39s nice to have things turn out as nice round numbers). And thus, the fabrics in my closet (at least these towels) presently have an RMC of 3.3%.
It should be pointed out that these tests may not quite measure up to the DOE procedures, since the 57700 dryer is a condenser model, which may not be able to "bake" fabrics absolutely dry. But I think this should be more than sufficient for our purposes... and FWIW, this long timed cycle did leave the towels feeling really dry, sort of stiff and rough, which would seem to be indicative of near-total dryness. As an aside, this also shows why it&#39s generally not good to dry fabrics this much in a tumble dryer - even in normal room conditions, clothes will usually have at least a few percent RMC, and if you use one of the slightly damp dry cycles, fabrics really will tend to feel better.
OK, now on to the actual spin tests! I used the "STARCHING" cycle in my AEG 88840, which consists of: one rinse, plus the standard spin program that concludes normal wash cycles. Timing each cycle carefully, I found each rinse to always be 6 minutes long, while the spin routine, depending on how long it took to tumble and balance everything, varied from 13 to 18 minutes in duration. The AEG spin routine spins up, slows down, pauses, tumbles, re-distributes multiple times before finally hitting the final spin at the rated speed, which is 4-4.5 minutes long. I also selected the "VARIOMATIC LOOSE SPIN" option, which supposedly helps reduce wrinkling and sticking to the drum walls, through increased variation in spin speeds. I&#39m still not sure how well this really lives up to its stated purpose, but I often leave it enabled, so this testing was performed with "VARIO" on.
I ran cycles with spins of 400, 600, 800, 1000, 1200, 1400, and 1800 rpm final spins (the 88840 doesn&#39t offer a 1600 rpm spin via the controls). The methodology was to take the "baked dry" towels, then put them into the 400rpm spin test... then remove them and weigh them... then back into the washer, for the 600rpm test... and so on, weighing the towels after each cycle completed. Results:
400rpm - 195.9 oz. total = 99.9 oz. H2O = 104.1% RMC
(yes, this is WET! It should be noted that with the 400rpm option, some of the mid-cycle pre-spins were faster than the 400rpm final spin, so a machine that truly used 400rpm would give even worse performance!)
600rpm - 178.0 oz. total = 82.0 oz. H2O = 85.4% RMC
800rpm - 156.5 oz. total = 60.5 oz. H2O = 63.0% RMC
1000rpm - 151.7 oz. total = 55.7 oz. H2O = 58.0% RMC
1200rpm - 148.8 oz. total = 52.8 oz. H2O = 55.0% RMC
1400rpm - 144.0 oz. total = 48.0 oz. H2O = 50.0% RMC
1800rpm - the first run at this speed couldn&#39t manage to balance perfectly for the final spin, despite several minutes of trying. The final speed sounded like about 1200rpm, or maybe a bit more, and sure enough:
"1800rpm" - 147.6 oz. total = 51.6 oz. H2O = 53.8% RMC
so, I ran the 1800rpm cycle again...
1800rpm - 141.9 oz. total = 45.9 oz. H2O = 47.8% RMC
(this time, the full 1800 rpm was indeed reached. Btw, with all sub-1800rpm speed selections, the washer ramps up fairly quickly to the rated speed, and holds it for most of the 4+ minute final spin. But with 1800, it ramps up more slowly, through what sounds like 1200-1400-1600, and only does 1800 for the last minute or so. This still works well, but is perhaps not quite as effective as a "full blown" 1800 might be. Further investigation of this would doubtless require a commercial centrifuge or Spin-X, etc...)
As a final confirmation all these figures were accurate, I then put the towels back into the Lavatherm dryer, on a COTTONS, EXTRA-DRY cycle. When that finished, I took them out, fluffed them, and put them back in for a 20 minute timed dry. Weighed the final results, and got: 58.4 + 37.8 = 96.2 oz., only 0.2 oz. different than the initial baseline! I again weighed the small amount of fluff from the lint filter, and again found it to be negligible, "0.0 oz.". So, it would indeed appear that all this is quite accurate, certainly reliable enough for this purpose.
Conclusion... while a "high speed" (1400rpm+) Euro obviously provides a HUGE performance jump over the average sub-600rpm TLer, and a significant advantage over 800rpm base model FLers, there&#39s only a modest advantage over a 1200rpm machine. If you have high utility rates or do a lot of laundry, this may still add up to a non-trivial savings over the life of the machine... but I don&#39t think I&#39d pay too much of a premium, purely for ultra-high spin speeds.
Of course, as you know, another major reason to consider washers with better spin performance (aside from energy-efficiency) is more effective rinsing! I haven&#39t run these tests yet (and still lack a TDS meter), but I can report that based on general observations, it sure looks like the AEG 88840 does very well in this department! Some mid-cycle spins reach at least 1000-1200 rpm, at least as far as I can tell, which should indeed help to remove a lot more of that pesky detergent residue! Time permitting, I&#39ll be posting some additional test results along these lines later this week.

黑妹

无论是滚筒洗衣机还是波轮洗衣机脱水的原理都是相同的，脱水后衣服的含水量的高低取决于脱水离心力的大小，离心力越大，脱水后衣服的含水量越低，这是毋庸置疑的，但为什么有的网友会认为滚筒洗衣机的脱水效果不如波轮，这里可能有很多原因，剔除主观原因不说，可能的原因滚筒洗衣机是按转数分档次的，转速越高，价格越贵，所以有些人受预算的限制买了低转速的滚筒洗衣机，如西门子550,只有550转，脱水效果当然就乏善可陈了。但有的网友买了800转以上的滚筒洗衣机，还是感到脱水效果不如波轮洗衣机，这里可能也有很多原因，比如电机皮带松弛打滑，实际转速没有达到标称转速，还有一个原因，滚筒洗衣机有些洗涤程序为了保护织物，对速度进行了限制，比如我用的西门子5200在洗涤羊毛织物的时候,最高脱水速度只有600转，即使设置在1200转，实际脱水速度也只有600转。如果是这种情况先仔细地查看说明书，熟悉各种操作程序。还有一种情况就是当滚筒洗衣机无法平衡，也可能降速，以保护机器。

可能有些网友离开学校久了，将离心力的计算方法忘了，在这里我再多打几个字，复习一下牛顿力学中关于离心力的计算方法：
离心作用是根据稳定角速度下做圆周运动的任何物质都受到一个外向的离心力F，这种力的大小取决于角速度（以弧度ω表示）、质量m和旋转半径R（以cm计算）。
　　F=mω^2R　　F常用地球引力表示，称为相对离心力（RCF）或者常用“数字×g”来表示。
　　RCF=ω^2R/980
　　在使用该公式时，这些关系需用“每min转数（r/min）”表示，这是表示离心机转动速度的普通方式。
　　由于（r/min）的数值可转换成弧度，利用ω=π（r/min）/30公式代入上式，得到下述换算式：
RCF-（πr/min）^2×R/30^2/980=0.00001119（r/min）^2•R

从上述公式中可知，转速越高离心力越大，洗衣机的内筒越大，离心力也越大，滚筒洗衣机的内筒直径一般都大于相同容量的波轮洗衣机，所以相同的转速也应该是滚筒洗衣机脱水效果更好。
也有的网友认为波轮洗衣机的旋转轴与地面垂直，不受重力影响，而滚筒洗衣机的旋转轴与地面平行，受到重力的影响，我们不防计算一下，在滚筒洗衣机的内筒直径为48厘米，转速为800转的时候，离心力为171.8G,即离心力为重力的171倍，重力的影响可忽略不计，如果是1200转，那么离心力将增加2.25倍，达到386G.

strongc

中学物理

黑妹

有时偏见比谬误离真理更远。不知我将计算方法写出来了，是否还有人会认为即使滚筒洗衣机内筒直径更大离心力也没有相同转速的波轮洗衣机大，呵呵。

废言

是否还要考虑结构方面的原因。滚筒的内桶是横置，波轮内桶是竖立的。衣物在高速旋转的内桶中，它所受到的离心力是不是一样的。衣物在滚筒洗衣机的内桶中，是否还受到自身重量的垂直重力影响~~~是不是可以忽略不计？

黑妹

最初由 废言 发表
[B]是否还要考虑结构方面的原因。滚筒的内桶是横置，波轮内桶是竖立的。衣物在高速旋转的内桶中，它所受到的离心力是不是一样的。衣物在滚筒洗衣机的内桶中，是否还受到自身重量的垂直重力影响~~~是不是可以忽略不计？ [/B]

当滚筒的直径为48厘米，转速为800转的时候，离心力达到重力的171倍，当然可以忽略不计了。如果发现滚筒洗衣机脱水效果不如相同转速的波轮洗衣机，可以肯定滚筒洗衣机没有达到标称转速。请厂家来寻找原因，比如是不是皮带打滑了等等。

Cherry

楼上是不是中学物理老师？

strongc

最初由 ttyp0 发表
[B]碰到外桶，受重力影响的确会沿着桶壁流走。但是水滴沿切线方向飞出也会被甩到桶顶，这时就不会沿桶壁流走，而是直接回到内桶。
我想这也是为什么滚筒鲜有下排水的原因吧。上排水不断有马达在抽水，可能对这种情况有所缓解。B]

水沿着切线方向飞出？？？？

难道，切线方向有喷射器？

ttyp0

最初由 黑妹 发表
[B]离心力是全方位，任何方向都可能，但是水滴将沿着外桶壁流走，即使掉在高速旋转的内筒外壁也立即被甩出去了，不可能重新再回到内桶里去的，对脱水效果并无影响。事实上，我实际使用滚筒洗衣机的体会脱水效果比波轮洗... [/B]

那么，看来我对中学物理知识的理解还是正确的罗。

你也开始说实际使用了，你无法从中学物理来解释了吗？
你现在用的滚筒是1200转的吧，和800转的波轮比谁脱水好，有何意义？
根据你实际使用，800转的滚筒脱水仍然比800转的波轮好吗？

ttyp0

最初由 黑妹 发表
重力的影响不到离心力的三百分之一，重力根本不能影响脱水效果，[B]水滴沿着切线方向飞出去[/B]，碰到外桶壁沿着桶壁流走，也不可能重新回到内桶。

qaz111

滚筒洗衣机就比波伦洗衣机好在能洗毛料衣服，但滚筒洗衣机费水漂不净是最致命的缺点！！个人认为西门子的滚筒洗衣机相对最好！！

mazda609

最初由 UNIELEC 发表
[B][QUOTE]最初由 mazda609 发表
[B]这是一个美国人的滚筒试验报告,可以参考。

I finally got around to running some detailed spin tests in my AEG.
For this series, rather than 10 lbs. of regular ... [/B]

It is remaining moisture content