Water filtration for steam generator

[matt wanasek]

Hello, I am working on a small scale mushroom farm. I am using a sauna steam generator to heat treat my substrate. I did my first run the other nite and found that my water hardness ( around 20 gpg in this area) built up alot of loose calcium in the unit after the run was done. I am looking for the easiest and cheapest way to treat the water before it enters the unit. Are there filters that will work to remove a good amount of the calcium ? or is a softener my only option? thanks in advance for any advice.

 

[Reach4]

If you feed the steam condensate to the mushrooms, I doubt that a softener would be a good idea. Those substitute sodium or potassium ions for calcium ions. Potassium salt costs on the order of 6x sodium.

I don't know the chemistry needs of mushrooms, but I really doubt that sodium would not be much worse than calcium for this. I am not sure about potassium, but I would still guess calcium to be better. (I understand I used a double negative.)

If the steam condensate is recycled back to the generator (being used as a heat boiler), than changes things. You could use a regular softener, or even use reverse osmosis water.

 

[Sponsor]

 

[matt wanasek]

If you feed the steam condensate to the mushrooms, I doubt that a softener would be a good idea. Those substitute sodium or potassium ions for calcium ions. Potassium salt costs on the order of 6x sodium.

I don't know the chemistry needs of mushrooms, but I really doubt that sodium would not be much worse than calcium for this. I am not sure about potassium, but I would still guess calcium to be better. (I understand I used a double negative.)

If the steam condensate is recycled back to the generator (being used as a heat boiler), than changes things. You could use a regular softener, or even use reverse osmosis water.

I am using the steam generator as a way to " superpasturize " the substrate, that being sawdust supplimented with various things like bran. i fill poly bags with the sawdust and supplement, fold the top over and tuck under to create a seal, stack the bags in a insulated container like a 55 gallon drum or watering trough with a false bottom and then pump the steam into the container in order to bring the substrate up to around 200F. Once it hits that mark i hold it for 8 hrs. that is why i have to run it for such a long time. the condensate is drained periodically from the false bottom to a floor drain, it would be nice to be able to recycle that condensate back into the system, but for right now im pretty tapped on funds, i threw my entire pension into starting this Operation so for now i am looking for the cheapest way to minimize the amount of calcium i am sending into the unit. would a filter like this help? https://www.zoro.com/3m-aqua-pure-filter-system-34-in-npt-10-gpm-ap43011/i/G0468316/

 

[Reach4]

I don't think so. Polyphosphates are used to prevent corrosion of pipes, but I don't know how it affects mushrooms.

Why generate steam? Can't you just pump hot water? I understand 200F is really hot water. If you cover the bed with good insulation, during the treatment, I would think the heat would be retained and not just be limited to the water at the bottom.

I don't want to imply that I have it all thought out, by any means. Just thinking about how I might do it.

Is this super pasteurization necessary? I guess so, or you wouldn't be working so hard to achieve it. Are you treating the bags, and then opening the bags later to spread the media? Would dry heat be OK? That would kill most stuff.

Back to the steam... if you heat water in a tub below the bags and steam or hot water vapor rises, then it does not carry calcium or sodium from the water up to the media. You can rinse out the tub. Sodium salt will rinse out readily. Calcium salts you could scrape or bang out maybe.

 

[matt wanasek]

Reach4 thanks again for replying. I am not in any way concerned with any of this effecting the mushrooms. Steam is just a very effective way to transfer the heat thru out the substrate. In a ideal world if i had a couple hundred grand to throw at this i would purchase a a large autoclave or retort to sterilize under 14.9 PSI pressure. ( that is the number where a vessel is considered high pressure and needs alot more inspection) This superpasturizing can do nearly as good of a job, but it takes far longer. a retort would have the job done in 3-4 hrs vs the 20 i have to run at atmospheric pressure. I will be doing 150-200 10 lb bags inside a insulated cattle water tank

after the steam treatment the bags are moved to a hepa or ULPA filtered area to cool. once they are under 80F i open them and introduce the fungi culture and seal the bag to allow the culture to grow thruout the mix.

Dry heat is not an option, it would possibly melt the bags or worse yet start all that sawdust on fire. The sawdust is hydrated to 60% moisture content before being bagged so possibly fire wouldnt be a issue. This is the method used by small to mid sized mushroom farmers. unfortunatly I am just in a area with very hard water, and i am operating in a business district so i have to use ways that can pass building inspection.

There are those that build there own boilers using one or more high wattage elements in a drum, some do the substrate right in the boiler drum, others with larger setups plumb that boiler into a larger insulated vessel. but both of those option would be considered a homemade boiler and would not pass code. the sauna steamer has all the needed safety features built in and is UL listed so i will pass inspection. That is the only option i have found that will work for me here aside from a even larger more expensive steam boiler.

All i am trying to do is cut back on the amount of calcium buildup that will occur in the unit during the run, i did my first one last week and so much line dust built up in the unit that it would not drain afterwards, I am sure i will burn thru elements fast with so much mineralization.

are there any inline type filters out there that will greatly reduce the amount of calcium that makes it into the unit? or is a water softener the only option?

 

[Reach4]

are there any inline type filters out there that will greatly reduce the amount of calcium that makes it into the unit? or is a water softener the only option?

Water softener is the practical option. It will not reduce the solids left over, but those solids will be easily rinsed out.

 

[Jadnashua]

Steam will be essentially pure water, and the boiling process will precipitate any minerals that were in the water.