Centrifuge safety question.

[kostbill]

Hello.

So I bought a used centrifuge, the harrier 18/80 refrigerated that can hold up to 800ml with one rotor or up to 300ml with another one.

 

I am now concerned about safety. I was browsing through centrifuge accidents in google last night and I got scared.

I read that centrifuge explosion is quite common ( ? ! ) in laboratories and it can happen for many reasons, a bad rotor being one of them.

But I have no way of knowing if my rotors are bad.

 

I noticed however that the bad accidents happened with very high speed centrifuges, for example somewhere near 55RPM.

Mine is going to be used only at about 4000 RPM.

 

Does anyone know if that kind of centrifuge spin can be dangerous?

 

Thanks.

[gfweb]

I've worked around centrifuges for years and never saw a problem.  If the rotor is intact and balanced it ought to be fine. Going that fast you ought to weigh the containers, not eyeball them to make sure they are equal.

 

Why do you need to spin that fast?

[kostbill]

You mean 4000RPM? Well I am mostly clarifying juices and follow Arnold's method.

I have a pretty good scale that can go a tenth of a gram so I don't worry about the weigh.

One of the rotors have a scratch, I will photograph it and upload later today.

[kostbill]

Well, I looked again at the the rotors and there is not a big deal scratch, just a small one.

 

I applied wd40, as the manual instructs, I also applied vaseline on the moving parts.

I am trying to find an anti-friction oil (but I suspect any oil will do here).

 

However still in the back of my mind I am afraid.

 

I read somewhere that centrifuges should be considered lethal laboratory instruments.

[blue_dolphin]

Don’t be too terrified of your centrifuge. 

Read the manual and use the machine with respect and care. Watch and listen as the centrifuge gets up to speed so you can stop the run if there are unusual sounds or vibrations. 

Never, never override any chamber locking mechanisms. 

Understand that rotors have speed ratings that are independent of the speed dial on the centrifuge itself. Just because a centrifuge can go up to 10,000 rpm doesn’t mean that is safe for every rotor so know the max rpm for your rotors when they were new and don’t ever exceed that. Rotor manufacturers tend to de-rate or lower the max rpm of older rotors so if 4,000 is the max for your rotor and you suspect it’s seen very heavy use, you may want to consider spinning a bit lower and longer to get the same result. 

That said, a small scratch is extremely unlikely to cause catastrophic failure at 4,000 rpm in an otherwise well balanced rotor. 

 

 

[kostbill]

Hi and thanks for the answer.

 

The rotor that can hold 300ml, can go up to 5574 RCF (about the same RPM)

The rotor that can hold 800ml, can go up to 6455 RCF.

 

I am using both at 4000 RCF.

 

Thanks for the info.

If anyone else have info on their centrifuge, please share.

 

Thanks.

[gfweb]

2 minutes ago, kostbill said:

Hi and thanks for the answer.

 

The rotor that can hold 300ml, can go up to 5574 RCF (about the same RPM)

The rotor that can hold 800ml, can go up to 6455 RCF.

 

I am using both at 4000 RCF.

 

Thanks for the info.

If anyone else have info on their centrifuge, please share.

 

Thanks.

 

RCF is a little different than RPM. RCF varies with speed and the radius of rotation, and I believe the angle of the rotor.

 

But whatever, If you stay within the limits you should be fine. Looking at the specs of your unit it seems like it will detect the rotor and not allow it to overspin.

 

I'd also clean it with bleach before you use it. Who knows what hideous stuff was in there before.

[kostbill]

Oh yes I know the conversion, that is why I am saying that it is about the same RPM.

 

I was trying to say that I am using both rotors lower than the max speed.

 

Also you are right, the centrifuge recognizes a rotor not meant to fit there, it displays something like: "bad id".

 

I used Virkon S (the one also suggested from the manual) to clean the rotors, then I let it dry and applied WD40, then let it dry and applied vaseline on the shaft and the inside of the rotor that touches the shaft.

 

This thing requires regular maintenance and I have no idea if the previous owners were doing a good job at it.