DIY Kalk Mixer- Design Inside comments please!

[cabrego]

All,

 

Here is a basic design that I have for a relatively cheap DIY kalk mixer. I have everything except the main container and the separator.

 

I am also looking for a solenoid to build in a safeguard feature to prevent ph spikes. Let me know what you think, the concept is pretty simple.

 

 

[Origami]

I've seen similar designs online that house an internal pump for circulation. Most of these designs just hang a pump from a rod or something secured to the lid or to the bottom of the reactor. The pump is kept sufficiently low so that it can stir the bottom while keeping suspended solids to a minimum. I don't think I've seen a separator plate implemented in these designs, however. Most pumps operate on a timer - just enough to keep the solution saturated.

 

Keep in mind the following: You want to keep kalk particles out of the sump. What you're trying to deliver is saturated effluent. That tiny powerhead you're showing will stir up the particules on the bottom, and pull them through the tube in your separator, forming a cloud in the top chamber. Some of the particles will be returned to the bottom chamber through the powerhead, but if the separator is a solid wall (with the exception of the perforating tube), kalk powder will begin to settle on the top of the separator plate. If the plate were heavily perforated, some powder could settle, but some would not. Eventually, the plate would clog.

 

I'm not sure what the purpose of the plate is anyways the way things are configured.

 

If, however, the pump were below the separator plate, the circulation would be contained below the plate. Still, if the reactor were configured correctly, I don't think you'd need a plate.

 

Keep in mind the maintance factor, too. You're going to have to periodically clean out and replace the kalk powder. In you're design, you have to pull the top off, remove the pump and pull the plate to get to the bottom chamber.

 

If the pump is only operating a fraction of the time, it will keep cool and will be less likely to develop hard calcium carbonate deposits in the high pH environment of the reactor. Still, it will develop deposits and you'll have to make sure that the pump is cleaned in an acid bath on a routine basis to keep it operating smoothly.

 

There are other DIY options such as a Nilsen reactor design which puts the powerhead on the outside of the reactor. Is there a particular reason why you're suggesting this less travelled path?

[cabrego]

Tom,

Thanks for the input. The details of how I could implement the separator plate are not worked out yet. The whole point of the plate is to keep solid Kalk out of the the sump which is why the separator would indeed be solid. I would have to tweak the power head to ensure that the kalk was not being mixed to aggressively, the power heads I have in mind are very low flowing types of power heads.

 

Upkeep of the power head is a big factor that I am considering and the design is by no means complete. Another option that I am considering is using a magnetic stirrer, instead of a power head, I am trying to find a good deal on one of these things.

 

I just purchased the container that I think I will use it is a spaghetti jar about .5 gallon and has a vacuum seal lid. The biggest challenge I have is finding fittings that I can use to hook up water lines. I just checked HD and they did have exactly what I am looking for....

[Origami]

Tom,

Thanks for the input. The details of how I could implement the separator plate are not worked out yet. The whole point of the plate is to keep solid Kalk out of the the sump which is why the separator would indeed be solid. I would have to tweak the power head to ensure that the kalk was not being mixed to aggressively, the power heads I have in mind are very low flowing types of power heads.

 

Upkeep of the power head is a big factor that I am considering and the design is by no means complete. Another option that I am considering is using a magnetic stirrer, instead of a power head, I am trying to find a good deal on one of these things.

 

I just purchased the container that I think I will use it is a spaghetti jar about .5 gallon and has a vacuum seal lid. The biggest challenge I have is finding fittings that I can use to hook up water lines. I just checked HD and they did have exactly what I am looking for....

 

Here's the point, if the pump's intake side is above the plate and the output side is below the plate (it seems that way in your drawing), you'll have circulation sucking particles from the lower chamber to the upper chamber.

 

Nilsen reactors are similar in design except they mount the pump externally. There is no plate but the pump is mounted somewhat low in the column. This keeps the suspended solids below and clear effluent at the top of the column. Here's what I mean: http://www.mv.com/users/besposito/nilsen.html. Note the cloudiness of the stirred kalk in the bottom part of the column and the relative clarity of the effluent at the top of the column. The pump intake keeps most of the particles low in the column acting kind of like a vacuum cleaner.

 

If designed right, you shouldn't need a plate. If you really want to use a plate, put the intake and the exhaust sides of the pump below the plate.

Edited August 7, 2009 by Origami2547

[cabrego]

Tom,

 

I think you are right. The separator plate was just an idea I cooked up having never worked with kalk before. I tested a power head in a container with kalk, and there will be quite a bit of circulation as you mentioned. I think I will be leaning towards a magnetic stirrer. I was trying to avoid it to cut costs but it makes live so much easier (I hope).

[dandy7200]

One thing to note, although it has little to do with the reactor itself. You would want a normally closed (NC) solenoid for this application rather than a normally open (NO). The theory is that you apply power to keep the valve open and when power goes out, the valve shuts automatically. The way you have drawn it with the NO valve, when power goes out your valve opens and you cook your tank.

 

On the mag stirrer. There are a couple really good designs out there for a DIY mag plate that you could probably build for less than $20. The stir bars are uber cheap on ebay but the plates do tend to be pricey. If you have trouble with google search let me know and I will see if I still have any bookmarked.

[dandy7200]

Actually nm that first part. I thought the box labeled RODI was your actual RODI unit. You have a top off bucket not hooked to the RO itself which is obviously the safer way to do things. I still like NC vs NO valves a little easier to tell when they fail.

[cabrego]

Dandy7200,

 

Thanks for the reply and offer. BTW, I just bought a mag stirrer on ebay for 30 shipped. Not as cheap as I would have liked but it will make life much easier on multiple levels.

 

As for the solenoid, I do not have alot of experience with them but this is how I imagined it operating,

 

1. I want it to be open the majority of the time during top offs, therefore, every time the float valve drops- RODI and saturated kalk fill the sump.

2. If the ph is goes up above some value I set, the ac jr sends a signalthat closes the solenoid thus only topping of with RODI. Until the ph drops below the set value. This a kind of safeguard.

 

 

By the way, do you know where I can find solenoids to use for this application?

[dandy7200]

Dandy7200,

 

Thanks for the reply and offer. BTW, I just bought a mag stirrer on ebay for 30 shipped. Not as cheap as I would have liked but it will make life much easier on multiple levels.

 

As for the solenoid, I do not have alot of experience with them but this is how I imagined it operating,

 

1. I want it to be open the majority of the time during top offs, therefore, every time the float valve drops- RODI and saturated kalk fill the sump.

2. If the ph is goes up above some value I set, the ac jr sends a signalthat closes the solenoid thus only topping of with RODI. Until the ph drops below the set value. This a kind of safeguard.

 

 

By the way, do you know where I can find solenoids to use for this application?

 

They are actually easier than that to set up. Get a AC120v NO solenoid with 1/4" NPT fittings and then 1/4"Male NPT to 1/4" OD instant tube fittings (John Guest) and then you wire a normal 2 prong extension cord to the the valve. You plug it in and it opens, you unplug and it shuts. Plug it into your DC8 and use the code to turn on or off depending on your set parameters. I would likely set ph values higher like 8.65 or so before it diverts. When you dose kalk sometimes you will have localized spikes but they go back down right away. Even 2-3 days at 8.65 would be acceptable so you are still in safe range. When you overdose you would likely hit 9.5+ type numbers and that is what I think your concern would be here. As to where to get the cheapest solenoids, I have bought them from Mcmaster.com in the past but didn't see them when I just looked it up. Maybe try filterguys or airwaterice or some of the diy sites that cater to the diy float switches and things or of course ebay. If you find one and not sure it is the right thing, post a link here and we can let you know if it is the right thingymabob or not

[Boret]

Solenoid:

BRK has them. I got two from him cheaper than I could find online. And they are the 120v type that close when not powered.

If BRK doesn't have any you can try www.autotopoff.com

[cabrego]

This is pretty close to what I had in mind- http://www.autotopoff.com/solenoid/solenoid_1.JPG and I believe this is what Dandy was describing too. I will give bRK a call and see what they have in stock. Thanks for the info...

 

 

By the way, can you give any tips on how to drill and not crack an acrylic tube? Any special drill bit? My current plan was to just make sure it was brand new and let the bit do the work.

 

This is what I am going to be drilling!

http://www.organizeit.com/imgwindow.asp?im...s/hr_oxopop.jpg

Edited August 7, 2009 by cabrego

[Coral Hind]

If you can get a hold of an old dishwasher you can take the solenoid off of it. They are located in the bottom front and are easy to remove.

[dandy7200]

This is pretty close to what I had in mind- http://www.autotopoff.com/solenoid/solenoid_1.JPG and I believe this is what Dandy was describing too. I will give bRK a call and see what they have in stock. Thanks for the info...

 

 

By the way, can you give any tips on how to drill and not crack an acrylic tube? Any special drill bit? My current plan was to just make sure it was brand new and let the bit do the work.

 

This is what I am going to be drilling!

http://www.organizeit.com/imgwindow.asp?im...s/hr_oxopop.jpg

'

 

That looks like the correct thingymabob. A hole saw with a drill that has a clutch is best for safely drilling. Believe it or not, new hole saws "bite" more and are not the best to use. When I get new hole saws I drill a few holes in some aluminum to take the factory burr of the teeth. This helps prevent the blade from twisting the plastic and causing the crack but rather shaves the plastic for a clean cut. The clutch on the drill also helps in case you do get a "bite" the tube is prevented from rolling with the drill bit and much less likely to crack.

[cabrego]

thanks for the tip, do they sell hole saws that small locally?

 

 

I found another solenoid on ebay, nice fittings built in, but I think brass is a problem isnt it?

 

http://cgi.ebay.com/New-Parker-120V-AC-Sol...id=p3286.c0.m14

[dandy7200]

thanks for the tip, do they sell hole saws that small locally?

 

 

I found another solenoid on ebay, nice fittings built in, but I think brass is a problem isnt it?

 

http://cgi.ebay.com/New-Parker-120V-AC-Sol...id=p3286.c0.m14

 

From the ebay listing : "The valve bodies are non-magnetic Type 303 stainless steel with 1/8" NPT female threads, and they have brass fittings in each port. The fittings were installed with Teflon sealant, so they are easily removed if you so desire." so all is good if you remove the fittings and replace with the acetal John Guest fittings. What size hole are you drilling?

[cabrego]

As for hole size I haven't quite figured out the final design.

 

My initial idea was to do something akin to what you have done with the JG fitting, but I am leaning towards a through wall type barb connection like this http://www.mcmaster.com/#5463k831/=334e7u +

 

I am thinking this is something like a 1/2 inch hole.

 

Using this would simplify connecting it to the top off pump. If I use the poly tubing I would have to use adapters to connect it to the top off pump. Since the system is not directly hooked up to the RO unit, using the poly is not really a requirement.

[dandy7200]

As for hole size I haven't quite figured out the final design.

 

My initial idea was to do something akin to what you have done with the JG fitting, but I am leaning towards a through wall type barb connection like this http://www.mcmaster.com/#5463k831/=334e7u +

 

I am thinking this is something like a 1/2 inch hole.

 

Using this would simplify connecting it to the top off pump. If I use the poly tubing I would have to use adapters to connect it to the top off pump. Since the system is not directly hooked up to the RO unit, using the poly is not really a requirement.

 

The fitting like that would probably work fine, you would probably want to add a rubber grommet to the inside of the fitting though so it sealed like a bulkhead. Another option is a uniseal. Stay away from the mcmaster brand seals though, they are not very flexible.

[flowerseller]

As for drilling holes, I have had fine luck lightly heating the area I want to drill.

Careful, too much and you get a twisted mess.