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wood chip
Stranger

Registered: 02/22/09 
Posts: 210
Last seen: 10 years, 3 months
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Re: pressure cooker limits [Re: lipa]
#18962043 - 10/10/13 11:15 PM (10 years, 4 months ago) |
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Those are retorts, autoclaves have steam jackets.
Unfortunately, those simple retorts are very hard to find. Do you know anyone selling them?
How do you hook it up to the boiler? Are there five holes in it? 1. Pressure gauge 2 safety blow out 3. drain 4. steam inlet. 5. steam vent/trap
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Aleon
The Power of Our Origins



Registered: 05/26/11
Posts: 1,127
Loc: Everywhere
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Re: pressure cooker limits [Re: wood chip]
#18962798 - 10/11/13 07:07 AM (10 years, 4 months ago) |
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Thanks for the info Lipa. You say the boiler for those was $3K but how much is it to install it? And are there any codes or regulations for using a boiler like this? Appreciate any info you can share on commercial retorts/boilers. Also best of luck to you; looks like you'll have a heady sized grow set-up here in December
-------------------- Mushroom medicines available at: www.swordandshieldwellness.com
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lipa

Registered: 07/24/07
Posts: 2,684
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Re: pressure cooker limits [Re: wood chip]
#18964250 - 10/11/13 02:19 PM (10 years, 4 months ago) |
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Quote:
wood chip said: Those are retorts, autoclaves have steam jackets.
Unfortunately, those simple retorts are very hard to find. Do you know anyone selling them?
How do you hook it up to the boiler? Are there five holes in it? 1. Pressure gauge 2 safety blow out 3. drain 4. steam inlet. 5. steam vent/trap
All of those. We have all the steam traps, vents n such. I just sent the relief valves in to get re-calibrated. I am just dreading all the piping I am going to have to buy. Ive already dumped 00,000$ into this project.
I will be installing my boiler myself with help.
The piping is specific but not at all hard. Follow the recommendations from the boiler manufacturer for near piping. Thats very important. As for codes, it is a low pressure boiler and I will be cycling it between 14-15 psi. Anything above 15psi or in some jurisdictions over a certain BHP require a boiler engineer on duty. I will be on site at all times and it will have safety lights and alarms for visual and audible safety.
Its very important to take time to sit down and learn about boilers and your specific application so everything runs smoothly. Also to plan out your maintenance routines on paper and to follow them to the T. If you don't your boiler will not last very long from what I have read due to oxidization.
Here is a great site to learn about steam engineering.
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wood chip
Stranger

Registered: 02/22/09 
Posts: 210
Last seen: 10 years, 3 months
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Re: pressure cooker limits [Re: lipa]
#18968139 - 10/12/13 12:32 PM (10 years, 4 months ago) |
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It is for those" boiler reasons" I started this post. I don't want to make more than 150 bags per run, and I want to sterilize my substrates.
A large pressure cooker would be great because there little chance of failure, no regulation, cheaper, no pipes, no electrical components, no scaling if using di water, less water, and less fuel. It seems like the 100 gallon pressure cookers fall in the space of neglected dimensions. College and hospitals infrequently use pressure cookers even when sterilizing small things. They use autoclaves instead of pressure cookers. Of course pressure cooker requires one to control the heat source which is not very hard work. Once empirically determined, which is based on mass and burners btus, the all American cooker has be turned down one time after it gets to pressure and will maintain that pressure for many hours with no monitoring maybe even days. Because growing shiitake mushrooms using bags is highly repetitive and burner control can be discovered over time I really like the idea of pressure cooking 100 bags per run. To me, growing shiitake mushrooms profitably at the 100 bag per day level centers around sterilization and controls in the cropping house, provided one is skilled in making spawn, has quality strains and has a source of free and consistent substrate.
Those retorts lipa shows are very old yet I am sure as solid as an all American pressure cooker. They have the added advantage of straight sides. I wonder how many boilers have been hooked up to it in the past.
I was thinking maybe a 55 gallon or larger pressure cooker or even a 55 gallon drum heated by a burner would heat unevenly. Which makes for inefficient heating and may require a steam boiler. Although I can find no one with experience using them.
I brought this up in another post, but still ask the question. Is there any reason why RR and friends use a boiler instead of direct fire for a single 55 gallon drum other than the loading and unloading convenience the drum offers being in a horizontal position and other non sterilization activities for example, heating the house etc.?
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wood chip
Stranger

Registered: 02/22/09 
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Re: pressure cooker limits [Re: wood chip]
#18968919 - 10/12/13 04:00 PM (10 years, 4 months ago) |
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Well I posted before I read that link Lipa posted. I am completely wrong about the efficiency.
A well designed boiler is much more efficient and able to transfer much more heat energy from the fuel. A gas burner heating a pressure cooker or 55 gallon drum boiler looses a lot of heat energy.
Even a small pressure cooker would be cheaper to operate using a very small efficient boiler.
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lipa

Registered: 07/24/07
Posts: 2,684
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Re: pressure cooker limits [Re: wood chip]
#18970149 - 10/12/13 10:01 PM (10 years, 4 months ago) |
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Quote:
wood chip said: Well I posted before I read that link Lipa posted. I am completely wrong about the efficiency.
A gas burner heating a pressure cooker or 55 gallon drum boiler looses a lot of heat energy.
I bet this is why RR switched to wood. Which by the way is sweet man labor only fuel. I would love to have a wood burning boiler.
I calculated it will cost me $33.25 in LPG to fire each run of 800lbs of substrate @ 15psi for 2.5 hours at my local LPG rate. I think thats fairy good for the amount of substrate.
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wood chip
Stranger

Registered: 02/22/09 
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Re: pressure cooker limits [Re: lipa]
#18972544 - 10/13/13 03:17 PM (10 years, 4 months ago) |
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Lipa said
''I calculated it will cost me $33.25 in LPG to fire each run of 800lbs of substrate @ 15psi for 2.5 hours at my local LPG rate"
Interesting, cooking six 5lb bags per run using an a 941 All American takes 26 days to sterilize the same amount. (150 blocks)
I can do this on a single 10 gallon tank of propane. I sterilize for 90 minutes at 17 psi. on a 15,000 btu propane stove.
If your calculation is accurate (assuming you have a high efficiency boiler) then at the 800 lb a day magnitude I doubt a behemoth pressure cooker is significantly more expensive to run when coupled an efficient external burner. My concern is uneven heating, however, if bags are raised high above the water shouldn't the steam temp/pressure be the nearly the same throughout once the air is removed?
Thanks for posting that link there is a lot of information.
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solarity
mm... my favourite food



Registered: 03/31/09
Posts: 1,590
Loc: UK
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Re: pressure cooker limits [Re: wood chip]
#18977300 - 10/14/13 04:02 PM (10 years, 4 months ago) |
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Quote:
wood chip said: Solarity
What kind of racks do you use and how to you remove them? Also, when you say sterilize do you mean with pressure or just a long pasteurization.
You got a good price. How does a 7kw sauna steam generator differ from a boiler? I am assuming it is electric and uses a lot of electricity.
Besides cook time, my interest in a massive pressure cooker is to reduce energy cost, water use and avoid all electrical components.
How many 5 lb bags of substrate can you run on a single cook?
Double wire shelves on top of the bags to separate them. Just lift out the bags. Pasteurised sub is in 30lb net bags so no sweat.
12 hrs at 95 C for "Super Pasteurisation"
It uses a 7kw electric element to boil water and make steam. But it switches in and out to keep the tank at 95C so about half that, costs roughly $6/run for spawn/sub.
I run smaller spawn bags and bigger sub bags but I guess about 80 5lb bags.
-------------------- Commercial exotics farmer for 8 years - now sold up!
Edited by solarity (10/14/13 04:03 PM)
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RogerRabbit
Bans for Pleasure



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Re: pressure cooker limits [Re: lipa]
#18978657 - 10/14/13 08:57 PM (10 years, 4 months ago) |
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Quote:
lipa said:
I am installing these in December and I am running them with a 7HP boiler that ran me 2900.00 with mechanical auto feeder. I calculated it will take 30-40 min to get them to 14psi and full of steam.  Lipa
I'll bet it takes at least two to three hours to come up to pressure. Remember, until all the substrates within the unit reach 100C, there will be no pressure starting to build. RR
-------------------- Download Let's Grow Mushrooms semper in excretia sumus solim profundum variat "I've never had a failed experiment. I've only discovered 10,000 methods which do not work." Thomas Edison
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lipa

Registered: 07/24/07
Posts: 2,684
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Ahhh yes. I had a doubt about my results. So it takes that time when empty.
I don't know how to factor in the density of the bags so I guess I will have to wait and see how it pans out.
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Shu
Vote for Humanity



Registered: 11/20/11
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Re: pressure cooker limits [Re: lipa]
#18987152 - 10/16/13 05:12 PM (10 years, 4 months ago) |
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Quote:
lipa said: Ahhh yes. I had a doubt about my results. So it takes that time when empty.
I don't know how to factor in the density of the bags so I guess I will have to wait and see how it pans out.
How many/what weight of bags in an autoclave run?
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lipa

Registered: 07/24/07
Posts: 2,684
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Re: pressure cooker limits [Re: Shu]
#18987794 - 10/16/13 07:25 PM (10 years, 4 months ago) |
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80 @10lbs each per run.
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