Dry Powder Acid

[Ian Wilde]

Just thought I'd post a couple of pictures of our dry powder acid system waiting to be commissioned.





Here are the central delivery connections on the back of the media panel.  A good job I think!

[Terry Simpson]

Hi Ian,
Out of interest why dry powder acid over bulk acid?

[fraser gilmour]

All new build units should be looking at this as an option, what's the point of transporting what is mostly water when we have a perfectly good municipal delivery system in place and the means to purify on site. Ian, does it have an integrated RO or is there a feed from your machine loop?

[Ian Wilde]

Hi Terry/Fraser,

As Fraser states, with bulk acid you are transporting (and paying for) 95% water that our own water treatment plants are capable of producing.

The system doesn't have its own RO and relies on a take off from your own system.

I have to admit though that it wasn't the thought of doing something good for the environment that first made us look at the system (it was barely even known to exist to us).  Because there is nowhere on the building to install a pump to take the bulk acid to the upper floors where the renal unit lives it would have meant strengethening floors and lifts to transport a 1 tonne palicon to the central delivery room and then being able to menouvre it around.

We had to find another solution.  It just so happened that a few weeks before I had been dropped a brochure off about the dry acid system.  Luckily I hadn't binned it!  We visited a couple of sites in Germany that had been using it for 10 years.  Needless to say we were happy with what we saw and heard.

[Chris Bates]

Let us know how it goes.
We had lots of problems with our central bicarb system when I first arrived. Dosing powder was a problem if there was any dampness, weekly disinfects, and microbio contamination. I stopped them being used instantly when we got 20 million times our action limit on endotoxins ( The reservoir bag looked like it had seaweed in it - I guess it shows the effectiveness of ultrafilters as no adverse symptoms were reported)
Most of these problems are probably not applicable to your system. I looked at central acid mixing systems but was wary after our experiences.
Chris

[Ian Morgan]

Hi Ian,
It looks like the Ecomix system. How will you accomodate the need for accurate laboratory analysis? I understand that when it is commissioned analysis of the composition is needed and you also need to get laboroatory analysis if the machine flags an error if the concentrate density is out or range. Also as the acid is prepared from a dry powder, do you know if the acid is citric or do they use sodium di-acetate?
We looked at this a while back but thought the cost per litre was too much compared with bulk acid, what did you find?

[Ian Wilde]

Hi Ian,

You're right it is the Ecomix system!

As part of the commissioning process the acid production has been tested and verified with a certified lab.  

All results came back within 98% of what it says on the tin which from what I'm lead to believe is a lot more accurate than the tolerances you find in traditional fluid?

I don't know about the type of acid to be honest but I will find out and post it here.

I believe the cost per litre is comparable to bulk fluid.  Our main problem with bulk fluid at this particular hospital is that there is nowhere for the truck to park and nowhere on the outside of the building for the pump connection to be fitted.

[Ian Wilde]

The system checks the density measurement and is looking for +/-0.04%.
A density measurement of +/-0.3% is still completely harmless.
It does recommend that if it should exceed +/-0.04% then you should do a lab test but I presume that this is to cover themselves?

[Chris Bates]

Hi Ian,
I am curious how your central acid mixing system is faring 6 months on ?
Chris

[Chris Bates]

Hi Ian,
Any update on how your dry acid system is working now ?
Chris

[Ian Wilde]

Hi Chris,

Apologies for the late reply.

(touching wood) we have had zero problems with the dry acid system 2 years on.  Never missed a beat.  I think we have made somewhere in the region of 120 batches up since it was commissioned.

[Chris Bates]

Hi Ian,
That's encouraging.
How often do you analyse the concentrate it produces ?
Does it require much tech/csw time starting batches taking samples, rinsing draining cleaning or whatever else is required ?
Are you saving any money?

I don't think this is for us at the moment as I remain unconvinced by the whale huggers who think this is saving the planet by not transporting bulk acid (we get the rest of the delivery on the same truck going the same distance, produced at lower overall energy cost in a big factory etc etc)

But I might be pushed into doing something like this if there are savings to be made.

[Ian Wilde]

Hi Chris,

Not sure if on the whole is saves much money as the cost of it per litre I think is comparable to the wet stuff.  And then there is the investment in the equipment itself.  If you have enough storage room for the carts then you could make a big saving on delivery charges I suppose but if you're already paying transport costs for your other consumables does this make much difference?
We haven't taken any batch samples since the commissioning process.  We treat it in the same way as you would the mixing system of your dialysis machine - if the volumes etc are all checked and mixed volumetrically then you should end up with the correct mix providing all the powder is dissolved and that is what the mixing system checks.  I suppose you could take random samples throughout the year though for piece of mind if you were inclined.
The unit is all self rinsing and as for technical time, the brochure states 12 minutes per batch but that is only if you stay and wait for certain cycles to finish.  We tend to press a button and then go back to it later when convenient to press the next button and so on and so forth.
We chose the system due to logistical and environmental issues around the hospital and dialysis unit itself and for these reasons it works for us.  
I believe the newest version has even less user input time as well as keeping track of your stock etc... so that you'll never run out of carts.

http://www.intermedt.de/en/ecomix-revolution/