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Tank covers or ping pong balls?

I have a facility that is looking into energy savings for their heated tanks. They would like to know which system works better, using tank lids or those large floating ping pong balls. The tank lids will save evaporation and energy but they seem hard to use, the ping pong balls float there, but to they really work and are you loosing them to the bottom of the tank often? Any experience with either would be a great help, thank you!

James Hanley
- Seattle, Washington
1999

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I had the same question, so I tried both. The floating balls seemed like a really good idea, but after some use, I did find disadvantages to them. While I never lost any to the bottom of the tank, they were constantly hiding in the cavities of the parts I was immersing. When you have a 190 degree part in your hand, fishing a little ball out of it is tricky. Also, I think a lot depends on the purpose of the tank. For my caustic tank, they were ok except as noted above. But for my nickel tank, I found that they prevented my seeing what was going on in the tank. Being able to see was more important than any heat loss. In all, I found the balls to be more hindrance than help. You may have to try them, but my experience lead me back to tank covers.

Paul Norman
- Odessa, Texas
1999

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1999

James,

Paul Norman's comments were interesting especially about any balls preventing him seeing 'what was happening'.

As you know, those 'balls' come in different sizes and in both hollow (cheaper) and solid construction. The complaint I used to get about the hollow ones is that some eventually get pinholed and sink, so I am told, to the bottom. (Personally I find that very hard to believe as the S.G. of Polypropylene [which is, I think, NEVER, EVER used for ping pong balls!]i s about 0.950 and is hence lighter than water.)

I assume that these tanks are being 'vented'. Hence, the first question is IS THE AIRFLOW SUFFICIENT OR PERHAPS TOO MUCH? If those tanks' ventilation systems were designed by Hoyle and a la Ventilation Manual, the chance is fairly good that the airflow is or could be excessive.

As lids can be a pain in the neck (weight, size, lifting problems, breakage etc) consider a half-lid. Why? Because obviously it would be easier to buy, use and support. Also because you could essentially halve your CFM consumption with energy savings on (fan) motors quite apart from less BTU losses. Remember that 'ventilation' often means Air Dilution and often that dilution is excessive. Also contributory are the or is the hood design.

I hope that helps somewhat.

Cheers!

Food for thought, anyhow.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).

Hi James,

I agree the covers are a big pain and the blow moulded hollow balls get damaged.

For this reason only we got special flying saucer shaped solid PP balls made which float and don't sink.

They cost us Indian Rupees 3.00 each and we market them extensively. We have sold about a million of them past seven years!

You might look for something similar in your part of the world. All the best, Khozem Vahaanwala

Khozem Vahaanwala
Saify Ind

Bengaluru, Karnataka, India

1999





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