This project was fun but I recommend buying the Harvest Right machine directly. I am not paid by them to say this. I wanted to build one to save money but it ended up costing way more than a HR freeze dryer. Not to mention how long it took (almost 2 years). Also, please don't try this at home. A lot of this can be dangerous if you don't know what you're doing.

@marmileson9712

2 жыл бұрын

Thank u for the effort and time to do and explain this. By the way, how is the taste?

@b5a5m5

2 жыл бұрын

Neat Project! Would love to see more about the automatic oil filter/changer.

@tjcd320

Жыл бұрын

Hey, Stay Fresh Freeze Dryer is an affordable option as well :)

@kylevillareal5567

Жыл бұрын

looks like you bought a harvest right, took it apart and filmed it after you spray foamed it.

@gustavoluca834

Жыл бұрын

Nice job, Aurelien, I'll like to build one of this, in my country we don't have any freezer dryer to buy, and I have skils welding and forming stainless steel, what kind of evaporator unit inside the vacuum chamber you use? coil, plate...I can see the condenser but not the evaporator, and if you can share this info, which gas you use to reach -40C?, thank you for your help. By the way my email is luca.gustavo@gmail.com, if you want to contact me directly. Thanks a lot

Thats not a freeze dryer, thats a Warp core

@dennislock3415

Жыл бұрын

😂😂😂😂😂

This is a herculean effort! Props my guy🙇🏾‍♂

Thanks man for your replies as well as the video. Solid advice!

Thanks a lot Aurelien for such details

Wow. Vraiment impressionnant bravo!

Beau boulot!!

I wish u had a build video and instruction, bc this is exactly what u was wanting.

good to frezzdry the ice hash, excellent 👌

Any chance you can poste a fully detailed video o. How you made it work?

Good job, there is nothing we cannot make at the amateur level, a person can even build a drone that can stay airborne for months surveying Antarctica if they wanted to tackle a project that big.

@Drew206619

9 ай бұрын

😂😂😂

Inspiring - thank you.

"Great Job Waltuh"

​@Aurélien Cacot ​please would be so kind as to list items used and how you went about putting it together as I know you mentioned getting the original but I can purchase one as they done deliver to South Africa

at what temperature are the heating pads for sublimation. and where do you get the control module from

Where did you get the condensing unit? And also the touch screen? I would like to build one half this size maybe a bit less than half only need about 2 trays and they don't have to be as long as yours, think you could give me some pointers in the right direction? What kind of condenser should I look for ? Should I look for a certain item to pull one out of or buy it new? How do I get everything to run through the touch screen? Would love to know, do you have a discord I could message you on?

You are now my new project-hacker HERO. Many salutes! Impressive project, And to do it with such thrift! Also thanks for taking the time and effort to address our questions with great detail. This is what made the internet great. I’m in the initial stages of contemplating whether I really want to jump into this project or not. I have a laundry list of questions for you. 1. You mention a sliding hinge on the door construction, how does this function? Is it the same design as on a harvest freeze drier? 2. What did you use for the door gasket, and door face material? 3. Due to the size of the gardens we maintain each year, I opt for the go big or go home mentality when building home-use projects. Im considering repurposing a 30 gallon stainless beer keg for my vacuum vessel. I tend to think it will be strong enough, but that will be determined when I implode it on accident, might even buy two, so I can stress test one of them 😃🥳🥳.My main concern at this point is whether the foodstuffs will offgas to the point of overwhelming my vacuum pump. What are your thoughts here? There are many cheap chinesium pumps, with either high-flow , or low-flow vanes that are available on the interwebs, might even set up a dual stage. 5. Did you determine what cause your pumps to prematurely fail? Did you run your pump continuously? Or cycle it? Did you provide a program for prevention of short-cycling the compressor motor? If so, What kind of control process did you use? 6. After buying the oil-less pump, was it still worth it to have built it, versus just buying a harvest-rite? 7. I like your solution to the hermetic pass-through wiring problem. Do you think silicon-coated, solid core wire at the pass through point could solve this? (Or is it even worth the effort and cost? Did the Cyano Acrylate glue ultimately provide a reliable seal?) 8. I’m almost certain the touch-screen display is worth the effort, just for the purpose of having an all-in-one control point and data display. Not to mention the silly price of $20-$30 dollars on top of the microcontroller 🥳. Any recommendations here? 9. Any recommendations on vacuum-tight solenoid-operated valves for the condensate drain? (It’s funny how difficult a task it is to get vacuum pressure ratings on solenoid valves) 10. Are there any issues with excessive wire self-heating inside the vacuum chamber due to lack of heat convection? If so, have you found any work arounds? 11. How many temperature probe sampling points did you use? 12. Run into any building materials that behave funny under the vacuum/heat conditions? Anything to look out for? 13. If you don’t mind my asking, What’s your back-ground. It’s an impressive and somewhat daunting project to undertake. This is why there are so relatively few well-performing, home-made freeze-driers out in the wild, let alone projects that are graciously documented on the inter-webs. 14. You put forth significant effort to repurpose your vacuum gage. In your opinion, how critical is the fidelity and accuracy of the pressure reading? Sorry for writing War and Peace…. If it’s easier to reply though a different method, pm me. Thanks again!

@aureliencacot2674

2 жыл бұрын

1. I'm not sure how the Harvest Right hinge works, but it's probably a kind a sliding hinge as well. Basically the hinge has an extra degree of freedom that allows it to move back and forth (you can see this at 2:53 with the long metal plates on the hinge). This allows the door to stay parralel to the door gasket as the pressure in the chamber decreases. 2. It was a 10x20mm rubber rope that I glued to form a ring. 3. Be very careful with the vacuum chamber. The first one that I tried imploded and this can be very dangerous. As for the vacuum pump I recommend an industrial grade one. If the control system is properly tuned, the food sublimating should not overwhelm the vacuum pump. The heaters must be precisely controled to keep the pressure at vacuum levels. 5. I think the vacuum pump failed early precisely because I was allowing the pressure to rise too much. 6. The oil-less vacuum pump is a huge scam. There is no oil but there is maintenance and that includes replacing a 300€ pair of seal after a certain period of time. It's also super noisy. As for the project as a whole, the build was not worth it. I should have bought the Harvest Right machine, it would have been much faster and cheaper (Harvest Right is not paying me to say that). 7. A silicone based resin would have probably been better for the seal. Super glue cracks over time. 8. I used a Nextion display for the touch screen. 9. A manual ball valve is probably a better option. 10. No. 11. I just used the thermistor from the middle tray (not the best solution). 12. No. 13. Electrical Engineering. 14. The accuracy of the pressure gauge is absolutely critical. The pressure variations in the system are tiny but they make the difference between a good and bad cycle.

@leerat8355

Жыл бұрын

​@@aureliencacot2674 please provide a list of items used and how you put it together as I cannot get one of those delivered to where I live in Africa

@leerat8355

Жыл бұрын

​@@aureliencacot2674 please would be so kind as to list items used and how you went about putting it together as I know you mentioned getting the original but I can purchase one as they done deliver to South Africa

Great job! Looking for an autoclave as we speak!

Hi so I have everything you have in that video but the controller ( your 7in touch screen) and I'm a hvac/industrial refrigeration tech. And how did you get the power into the chamber

Why can't I find any info about a build where you basically hook up a vacuum pump to a small chest freezer? Is there a reason that wouldn't work that I'm just missing?

Hello , Can you explain in more detail how did you build the condensing unit ? I be happy to pay you for youy info , thanks from Mexico

How did you learn how to do this?! Is there a form that goes over what are the essentials to build a freeze dryer? This video needs more views. A lot of talent put in this craft. BRAVO!

@aureliencacot2674

4 жыл бұрын

This was a lot of trial and error. As far as I know this is the first fully automated DIY freeze dryer on KZread and possibly on the Internet. There are simply no tutorials for this. This is a very complex project, the essentials for making this work are: - A good vacuum chamber - A low temperature condensing unit - A heated shelf inside the chamber - A reliable vacuum pump - A way to accurately measure very low pressure - An electronic circuitry to follow the freeze drying cycle (just google "freeze drying cycle" and you will find diagrams)

@bobbyoneil6823

4 жыл бұрын

Aurélien Cacot would you share your sources for materials? mainly the heating mats and the controller? if you make a video on how you made the controller you would be a hero in all freeze-dry facebook groups across the world!! great build! excited to see more footage!

@aureliencacot2674

3 жыл бұрын

@@bobbyoneil6823 The heating mats are simply 3D printer silicone heatbeds. The controller is fully custom made but features an Arduino at its core. The arduino code is very rough and basic, maybe I will make a Git repository for it.

@Edgar-so9of

3 жыл бұрын

@@bobbyoneil6823 what freeze drying community are you in?

@bobbyoneil6823

3 жыл бұрын

Edgar check out data analytics for harvest right on fb.. thats the best!

Can you explain how the "vacuum oil filter" works? I just bought a new vacuum with new oil, after just 1 hour, the oil gets brown :( Thank you very much

Wow this is the best DIY freeze dryer I have seen I really want to make my own but I need help, if I was to draw some plans could you look over them for me? I would really appreciate it😁

@andreafavero3271

2 ай бұрын

Did you manage to find help?

It looks very good and well managed. I am also trying to build the same. Can you share more about this

@aureliencacot2674

4 жыл бұрын

Here are the key things needed to make this work: - A thick wall vacuum chamber with no leaks and very good thermal insulation. - An LBP condensing unit that can reach -40°C. - A high accuracy digital vacuum gauge. I hacked a Testo 552 for this. - A very strong door with a sliding hinge that allows the door to move back and forth as the pressure changes. - A waterproof heated shelf with a temperature sensor. I used 3D printer silicone heatbeds. - A reliable control circuit. I used an Arduino Mega with a custom relay board. The touchscreen is a Nextion 7".

@bobbyoneil6823

4 жыл бұрын

Aurélien Cacot can you link us with some info on the heatbeds you mentioned. what are they?

@aureliencacot2674

3 жыл бұрын

@@bobbyoneil6823 fr.aliexpress.com/item/32665782192.html?spm=a2g0s.9042311.0.0.27426c37ounLtF I ordered the 220V 200W version. There are 12 heated beds in total (2 underneath each tray).

@sijo2084

2 жыл бұрын

@@aureliencacot2674 in the drying cycle and final drying cycle.what temperature you are maintained on the heat pad.? What is the cooling compressor spec. Can we use 260 L refrigerator compressor?

While put materil on tray material is melted after one hour. What should I do? Also, while putting in all trays, the condenser temp is not reaching -40

This is great. Thanks for sharing your experience. I am planning to build one. What is the size of your autoclave? And what is the size of the drying trays? I would also like to know the size of the heat mat you use.

@aureliencacot2674

3 жыл бұрын

The autoclave is 36cm in diameter and 70cm long. The drying trays are actually the large trays from Harvest right, the size is is 22 cm x 50 cm x 2cm. The heating mats are 3D printer silicone heatbeds, the size is 30cm by 20cm and I use 2 per tray.

@embee2144

3 жыл бұрын

@@aureliencacot2674 Thank you.

@quangduy6354

3 жыл бұрын

what about your FD :D I want to build one like you

Could I ask how the freeze dried tacos were?

How can you make your condenser system go below -40 Celsius? normal condenser system just down to -20

Great 👍. What is the thickness of stainless steel cylinder ? Cooling compressor is Air conditioner or refrigerator.? Compressor spec.?

bravo c'est beau je cherche justement a faire ca , tu est frigoriste ? tu peut en dire un peut plus sur la chambre je cherche du coté des autoclave mais partie trop épaisse je pense ... merci et encore vraiment bravo c'est top

Thank you for posting the video Aurélien, and for answering questions about it. Very much appreciated. :) I know you say you took 2 years to build, but if you had to make a second one, knowing what you know now, and you already had all the parts in front of you would it still take 2 years? Did you use refrigerant grade R290 or was it like Barbecue gas or something? Legalities aside, is it mission critical to have a compressor specifically designed for R290?

@aureliencacot2674

3 жыл бұрын

Honestly even if I could work on it full time and had all the components it would still take at least 2 weeks. There is a lot of welding, soldering, tube bending, and testing involved. Not to mention the mod of the vacuum gauge. For the refrigerant, I actually tried barbecue gas at first but it didn't work lol. Then I used proper refrigerant grade R290 and it worked. For the compressor, what is important is that it must be a LBP compressor. Otherwise the system will not reach -40°C. If you intend to use R290 I strongly recommend that you use a compressor specifically designed for R290.

@TeslaWasHere

3 жыл бұрын

@@aureliencacot2674 I'm very curious as to how you modded the vacuum gauge.

@aureliencacot2674

3 жыл бұрын

​@@TeslaWasHere ​ The probe is a Testo 552. The probe has a connector to interface with other Testo devices but Testo refused to give me details on the communication protocol. So I opened up the probe and found a UART line with my oscilloscope. Data was being sent every second a 57600 baud. Among this data I found the pressure reading using an Excel spreadsheet.

@edhog

2 жыл бұрын

@@aureliencacot2674 haha that’s AWEOSME Well done on the entire build. I’m building one myself at the moment. What did you use for a vessel? I have a 200L autoclave I’m repurposing. What’s your thought on not having the vessel refrigerated? Is it an absolute must?

@b5a5m5

2 жыл бұрын

@@edhog You'll need a cold trap one way or another to condense the water vapor back into a solid. You don't want all that water vapor going through the pump.

please more videos and parts list?

In the video the label " The condensing unit " is displayed when the compressor is shown. Do you use a capillary tube as expansion device ? The tricky part in this build anyway is how to trap the water vapor during sublimation. If you could explain the details of the refrigeration circuit.. it is great !

@aureliencacot2674

4 жыл бұрын

The condensing unit consists of a 300W LBP compressor, a 1000W condensor, an evaporator coil wrapped around the vacuum chamber and a capillary tube.

@techfieldsales9824

4 жыл бұрын

@@aureliencacot2674 Thank you for the feedback. Where did you find the evaporator from ? An old refrigerator ?

@aureliencacot2674

4 жыл бұрын

@@techfieldsales9824 The evaporator is a copper tube that I found in a scrapyard.

I am very interested in doing a similar project. I have a large freezer and I have a couple of old refrigerator compressor's and some condensors laying around. Can I not build a vac chamber and pull vacuum with the compressors on my already frozen food and accomplish 'freeze drying'?

@aureliencacot2674

3 жыл бұрын

The vacuum from a refrigerator compressor will not be enough. Freeze drying can only take place at pressures below 300Pa. Your will also need to heat up the food but not too much so as to keep the pressure below 300Pa. For this you need a microcontroller or PLC to monitor the pressure and temperature and control the heaters. It's a delicate process to control but it can be done with the right equipment.

Is heat applied to the frozen product at the same time the vacuum is started? How long would sublimation take without heat? Awesome job!!!

@aureliencacot2674

3 жыл бұрын

The sequence is this: freeze the product (-40°C, 8H) -> pull a vacuum (wait 20min for it to reach 200Pa) -> turn on the heaters, regulate the heat in order not to exceed 50°C and 200Pa (24H) -> turn off the heaters (end of the cycle) -> the user opens the chamber -> turn off the freezer. I don't know how long sublimation would take without heat but you would have to either wait a really long time or have a very low temperature cold trap (-80°C).

Could anyone tell me how long the temp of -39 be maintained and how long during the process are the heated shelves on

What did you make the main chamber from? Its seems fairly robust and is it a double wall or just a single with the spray foam insulation around it?

@aureliencacot2674

4 жыл бұрын

The chamber is that of an autoclave that I found in a local scrapyard. It is made of stainless steel and has 6mm walls. There were several threaded ports on the side which made it easy to connect the vaccum hose and the heater cable. As for the insulation, I first added fiberglass wool held together by a steel tube but that wasn't enough so I added spray insulation on top. By the way the first chamber that I made was with a water heater tank that had 3mm walls. It collapsed at 0.6 ATM. So 6mm walls is not overkill I think.

@myselfnegative4290

4 жыл бұрын

@@aureliencacot2674 my chamber is just SUS304 with 3mm thick, from D=45cm to D=80cm.

@abdussamadshaikh3467

2 жыл бұрын

@@myselfnegative4290 Sure 3mm thickness ss sufficient for 45cm inner diameter and 60 cm depth for a vacuum freezer cylinder? I have built a 45 cm diameter and 60 cm depth cylinder in 5 mm thickness but in Mild steel sheet. But I want to build another in stainless steel.

@myselfnegative4290

2 жыл бұрын

@@abdussamadshaikh3467 3mm ss304 is VERY THICK with D450 cylinder. I tried D800 and it is going well. No bad things happened.

Good job, how did you get to -45 °C (-49 °F)? Was it difficult? is it necessary to reach that temperature?

@aureliencacot2674

4 жыл бұрын

In order to reach such low temperatures, I used a LBP compressor with R290 refrigerant. Setting this up was quite difficult for me but it should be easy if you have some experience with HVAC. The -40°C temperature is necessary because some foods have a freezing point below 0°C (icecream for example). Whatever you put in the machine needs to be completly frozen in order for sublimation to take place (the main phase of freeze drying). Otherwise things would just melt.

@sparc5

3 жыл бұрын

@@aureliencacot2674 are you using a lubricant with the R290?

wouldnt it be simpler to set up a cold trap made from mini fridge parts in between vac chamber and pump? this is impressive diy, but to make something that looks and works exactly like a harvestright seems likely to going over budget, no? amazing diy video though, thank you for sharing!!

Parts list please

Links to the parts?

Could I use refrigerated vapor trap with a vacuum pump? I just want to freeze dry something, and that’s what I have available to me right now.

@aureliencacot2674

3 жыл бұрын

That's what I tried at first and it did not work at all. You need at least -40°C to make this work.

@gediminasgresevicius2901

3 жыл бұрын

@@aureliencacot2674 how did you get -40C?

Praise the LORD for creating these awesome machines!

did you use a raspberry pi by chance for that touch screen option?

@aureliencacot2674

3 жыл бұрын

No it's a Nextion display

How much to buy one ?

I thought it was suppose to freeze it, why do you need heated shelfs

Nice, Very Good. Is the software your own or something exists to buy?

@aureliencacot2674

3 жыл бұрын

The software is my own, it is an arduino code

@goldcoasttime

Жыл бұрын

@@aureliencacot2674 were you happy with the quality of the product you produced, the berries looked great, what vacuum pressure is required to operate a freeze dryer, if you killed 3 pumps I would assume it was ice or moisture is that your thinking too? great job do you think a stainless drum could be use? would it require reinforcement rings welded to it like a submarine hull?

Please, more info on software?! Looks functional!!!

@aureliencacot2674

4 жыл бұрын

The software is custom made. The freeze dryer runs on an Arduino MEGA with a custom PCB. The software is in two part: there is the C++ code for the Arduino (1000+ lines) and there is an HMI file for the display (Nextion Enhanced 7"). Also, I had to reverse engineer a proprietary communication protocol on a digital pressure gauge in order to read the pressure values.

@pavnowak

4 жыл бұрын

@@aureliencacot2674 oh, as simple as that hey? 😅 Loved the project!

@JiggerzWithAttitude

3 жыл бұрын

@@aureliencacot2674 Did you develop the software from scratch? Have you thought of open-sourcing the software? I'd love to contribute to an opensource project such as this.

Thanks for sharing this project. My god! How did you achieve putting heaters into the tank without vacuum leaks? I mean, the cables have to go out with perfect sealent!!! HMI with arduino?

@aureliencacot2674

3 жыл бұрын

That was one of the most difficult part. I used a silicone wire and silicone sealant to get a good bond. It was not enough. Air was actually leaking from inside the cable. I put some CA glue on the end of the cable while the vacuum was on and it sucked the glue on the entire lengh of the cable which made the cable airtight. The HMI is working with an arduino.

@darrentummon4855

3 жыл бұрын

​@@aureliencacot2674 could I please ask you to PM in instagram or messenger. I'm also building my own freeze dryer and I just have one or two nagging questions that no one else seems to think about. Thanks in advance

@quangduy6354

3 жыл бұрын

@@darrentummon4855 I'm planning to build one, can we chat ?

@sparc5

3 жыл бұрын

@@aureliencacot2674 hermetic compressors use Fusite around conductors. I was thinking about building one of these myself, and knew this would be hard. You could probably get by with one wire if you use the chassis as ground. Congrats on getting this project complete.

good

Oh cool! I need a machine that can turn banana chips into raspberries 😅

Hello, build one for me, a 100kg processing machine if possible!

Hello I have yet to read all these comments I've just not come across this .. what was your total cost to build?

@aureliencacot2674

3 жыл бұрын

The total cost of the components is around 2200€. If I include the cost of prototyping and breaking stuff it's over 3500€. The most expensive part is the oilless vacuum pump which costs 1600€ (the one in this video is a 300€ oil pump).

Nice. I have read the other comments. I am interested to make this. Can you share some diagram. I mean how system works. We can do the welding, assembling and software programming.

@aureliencacot2674

4 жыл бұрын

Sorry but I don't have any plans / CAD models. The main problem is that the entire machine is build around a stainless steel chamber that I randomly found in a scrapyard. The walls are 6mm thick so I really don't know how I would have been able to bend this into shape if I had to make the chamber from scratch. There is also the condensing unit + digital vacuum gauge + vacuum pump + heated shelf + microcontroller. With all that here is how the system works: - COOLING PHASE: At ambiant pressure, the chamber is cooled to -40°C during 5-8 hours (adjustable). - The vacuum pump turns on. - After 20 minutes, if the utimate vacuum pressure is not reached the cycle stops (there may be a leak). An error screen appears. - DRYING PHASE: If the vacuum pressure is reached, the heated shelf turns on and reaches 50°C (adjustable) over 5-10min (adjustable). This phases lasts 8-12H (adjustable). - If during the drying phase the pressure exeeds a high threshold of 300pa (adjustable), the heaters shut off. They turn back on if a low threshold of 200pa (adjustable) is reached. - If the heaters are turned off, the drying chrono is stopped. - After the 8-12H drying chrono is done, the cycle ends: the heaters and vacuum pump are turned off but the condensing unit stays on. Trivial, isn't it?

@sstipl

4 жыл бұрын

@@aureliencacot2674 Thanks for the reply . I have a few more queries Can you help for it. How i can contact you directly.

@aureliencacot2674

4 жыл бұрын

@@sstipl What else do you need to know?

@sstipl

4 жыл бұрын

@@aureliencacot2674 The water which evaporates is taken out by the vacuum pump or is it again condensed back . I need some more details about the use of condensor. Is it only used during the freezing period. Or there is any more use of it.

@aureliencacot2674

4 жыл бұрын

@@sstipl The evaporating water condenses on the walls of the chamber, this is how it is removed, not with the vacuum pump. The condensing unit is turned on during the entire process (freezing + drying).

Is that a VW fuel water separator?? Looks awfully familiar.

@aureliencacot2674

3 жыл бұрын

I don't know I got it from a car repair shop

There is something I can't understand about DIY freeze-drying, and that is why people seem to make it so complex. Not that I have a problem with that. I think this video is awesome, but here is my idea and you might be able to tell me if it would work or not, but my idea is to convert an old refrigerator into a freeze dryer. I freeze my food in a normal deep freezer, I then move my food to my converted freeze dryer fridge. The fridge already has an airtight seal on it, like all fridges do, I have heated shelfs in the friedge. I create a vacum inside the fridge, and dry the food in said vacum. Would that work? If so, why not? I would greatly apprciate any feedback or info. Thanks.

@ArthurGomesZah

11 ай бұрын

I just watched another video and this is the info I remember, so don't trust me. What i understood is that the pressure needed for the water to go from solid to gas is very low, which you'll not be able to get in you vacuum sealed freezer.

@remotechase4627

11 ай бұрын

​@@ArthurGomesZah From what I understand a vaccum is the absence of pressure. idk

@destructionfromthehills204

10 ай бұрын

@@remotechase4627 The liner inside the fridge would implode, a vacuum is negative pressure, a perfect vacuum like in space is a bit different, in our normal day to day lives we have pressure exerted on us by our atmosphere, I believe it's around 40ish pounds, when we remove said atmosphere from a container the pressure drops inside however it still has the the atmosphere pushing on the outside. If said container can't hold the pressure on the outside it collapses. So something thin like a refrigerator often made of sheet metal, foam, and plastic would implode. Think of it like sucking the air out of a water bottle.

@remotechase4627

10 ай бұрын

@@destructionfromthehills204 I've never thought of it like that before. That was a really good explanation. Thank you for taking the time to write that for me. You have made a big difference on my future project. Thanks.

Hello! this is a great project that will give impetus to the development of many creative engineers who do not work in this field. Thanks. This also interested me. 1) Are there any updates in your project now? Do you plan to do the second version and when? 2) Are there any sources by which you calculated the parameters of the cooling machine?

@aureliencacot2674

3 жыл бұрын

Unfortunately the freeze dryer is no longer functional. I broke 3 vacuum pumps (this one and two $1600 oilless pumps). I still don't fully understand what is wrong with my design, I mainly just copied the Harvest right freeze dryer. I got the part number of the cooling unit from a video of a guy who showed the internal components of the Harvest right machine.

@valerijt4344

3 жыл бұрын

@@aureliencacot2674 I've read a lot of videos about Harvest right freeze dryer. Also studied such patents as: US9459044 and US4780964. Your unit is really similar to the Harvest right freeze dryer. You use a similar drying algorithm: have upper and lower pressure points and work between them using heaters. However, Harvest right f also had problems with the vacuum oil pumps, and the buyers themselves corrected them. You have added the same filter to the pump. I have a hypothesis that the boundaries of 200-300 pa are very tight. the border of 300 will be more careful for the vacuum system. 500 ra - it will still be below the triple point of water. Harvest right - also switched to an oil-free pump. But for me it is very dear. My plans are to create a working system for 100,000 rubles (1254 dollars - what a bad course we have).

@alexa.davronov1537

3 жыл бұрын

Why the hell it's so expensive?

@alexa.davronov1537

3 жыл бұрын

Оставь почту.

Cost plz.tyia

Hey what type of refrigerant did you use for this unit?

@aureliencacot2674

3 жыл бұрын

R290

Can I pay u to make and ship me one

R U dr. Emmett Brown?

This design isn’t quite right. If you don’t cold trap that sublimated ice it will just go into the pump and ruin it after a while. You don’t need to filter the oil, you need to trap that vapor and stop it from entering the pump oil. The dry chamber itself doesn’t need to be held at the low temp, and really only needs to be sub freezing temp until the pressure inside is low enough, around 400-500 micron. After that, sublimation cooling goes into effect and actually slows the process down, holding the temp below freezing, which is why freeze dryers usually have shelf heaters to counteract that cooling effect. Look up foreline/thimble cold traps. You need to use the mechanical cooling on the cold trap, not the dry chamber. If yo want to deep freeze the material inside the dry chamber, you’ll need to use two compressors, a cascade system, or modify that current compressor/condenser system to be able to cool both the dry chamber and the cold trap, and at varying times. First you deep freeze material inside the chamber, then you start the vacuum and move the mechanical cooling onto the cold trap, and once the pressure inside is low enough, you begin to war, the trays, gently and usually not higher than 50f.

@edusmdp

3 жыл бұрын

ccan i contact you? y have a couple of cuestions!

@aureliencacot2674

3 жыл бұрын

I know this isn't the traditional freeze dryer design. My design is actually based on the harvest right freeze dryer which has no seperate cold trap. And it has the same temperature characteristics: -40°C on the chamber wall and 50°C on the shelf. What you are saying about the vapors destroying the pump is propably very true. I have actually destroyed 3 pumps, one oil pump and two oilless pumps. I don't know how the harvest right machine deals with this issue. Instead of redesigning the entire freeze dryer, I might try to build a novel type of vacuum pump: a magnetohydrodynamic sprengel pump. This pump would have no seals or oil and would only have one moving part: liquid gallium.

@roymarable5860

3 жыл бұрын

Can you explain the water trap? How cold does it need to be? Thanks

@jonosterman2878

3 жыл бұрын

@@roymarable5860 The cold trap protects the pump by taking the sublimated water vapor and freezing it back to ice, so the doesnt reach the pump and condense into liquid inside and make the oil watery, or get on seals and gaskets. It goes between the dry chamber and the pump, although the cheaper Harvest Rights, and this DIY model, have this function inside the dry chamber, which means heated shelves are mandatory, otherwise you cannot warm the dry chamber up during the second stage of drying. The trap temps mostly depend on what is being lyophilized, but for items that are just holding frozen water and not some solvent or reagent, the temp is typically -50f, but sometimes its safer to go a little lower, like -55 to -60f.

@adriandatri

2 жыл бұрын

@@aureliencacot2674 When you say you have destroyed an oilless pump, are you referring to the new pump you show in this video: kzread.info/dash/bejne/f3l4lJucYKu0gso.html

pls, can you make a tutorial??

@aureliencacot2674

4 жыл бұрын

I would like to build a better version first. This machine was a nightmare to build, it took me 2 years and 1500$+ . The vacuum pump failed shortly after I made this video and I had to buy an oilless pump which cost another 1600$. Then this pump failed after a year and I had to repair it (another 1000$). Even if I made a tutorial and gave you the list of all the parts you would still have to be experienced in welding, soldering, programming and HVAC. The hardest part was loading the condensing unit with refrigerant. It can be quite dangerous if you don't know what you are doing. If I find a cheap oilless vacuum pump and an easy to assemble refrigeration system them I might revisit this project and release the plans for a new freeze dryer.

@martinhodek6394

4 жыл бұрын

@@aureliencacot2674 Is there any reason why you do not like oil vacuum pump? Just asking, I am new to the topic.

@aureliencacot2674

4 жыл бұрын

@@martinhodek6394 The oil pump is super messy. It tends to produce a lot of oil mist. The performance decreases over time even with the automatic oil filter. Eventually I had to replace it because it was not longer reaching vacuum pressure even after a complete oil change. The oil pump is also significantly louder than the oil free version.

@aureliencacot2674

4 жыл бұрын

@@capt.diractance9926 Two things happened: - One of the tip seals was crushed for some reason. - The scrolls had some limescale and debris accumulated from all the food batches. To prevent this I installed an intake filter. Also you should know that the oilless pump from harvest right (I bought mine directly from the supplier in China) is very hard to disassemble. I had to use a hammer to open it up and see what was wrong. I made the mistake to use hydrochloric acid to remove the limescale which erroded the aluminium scroll assembly. The pump would no longer reach vacuum pressure after that so I had to buy a new scroll assembly which cost me $1000. I think the pump would have been OK if I had not used the acid and just replaced the tip seal (which still costs $300).

@myselfnegative4290

4 жыл бұрын

@@aureliencacot2674 it took me also 2 years to build haha.

tacos

@Aurélien Cacot could I please ask you to PM in instagram or messenger. I'm also building my own freeze dryer and I just have one or two nagging questions that no one else seems to think about. Thanks in advance

@aureliencacot2674

3 жыл бұрын

Feel free to ask here

@darrentummon4855

3 жыл бұрын

@@aureliencacot2674 sorry it took me until now to see your reply. Do you happen to have a process flow diagram of your design ? I understand the science of what is happening here, BUT, at least one point (at this stage) is left unanswered. This being that your vacuum chamber, or where the product is being chilled and vacuumed down, must have a upstream line that introduces dehumidified air to basically flush the moisture boiled off, into a condenser chamber or zone. Otherwise how does this moisture get taken away?? And then this moisture can be drained off prior to being sucked up by the vacuum pump. So I was hoping that you could provide me a P&ID or Process Flow Diagram to illustrate this feature. If possible, I would prefer to talk off line. Although this is selfish of me, it would be easier for me. See totally selfish of me. LOL Thanks for your time and especially for replying. :-) dwt068@gmail.com