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iceman31
02-07-2013, 01:09 PM
Hi All

This is a very important question from me. I don't want to start discussing why it's so important however I would be very grateful if people could take the time to help me solve it. I have been trying to solve this for months now however have thus far been unsuccessful.

Basically I want to slow freeze some poultry and cause maximum ice crystal damage. Ice crystals in meat develop passed the freezing point -2.2c(for poultry) and up to -4c. Therefore I need the meat to spend enough time in this zone in order to do damage I need.

In order to do this I understand one simply needs to slow freeze the item however I am having trouble getting the freezer to slow freeze in the fist place and am wondering if there is an easy way to do this.

Firstly I am trying to accomplish this from home (currently using a domestic freezer) however domestic freezer temps start at -10c and below. The rate of freezing I have found is way to fast with domestic freezers so I haven't been able to acquire the results I want.
I have done things like insulate the meat in a box with towel but didn't see evidence of excessive purge/ice crystal damage and am guessing the items froze quickly.
I also left the door open in order to bring the temperature down however the temp fluctuates too much e.g. is still to low or sometimes too high e.g. sometimes goes to 0 so I am having difficulty controlling that.

Anyway somebody recommended to me that I should freeze at -5c and just leave the item there for a few days. However I understand it is not as simple as that. Firstly, since I cannot even get my freezer to come to -5c so I cannot test it this easily.
Secondly I understand it is not the temperature that determines the RATE of freezing but actually:

a) cooler capacity
b) product load

Guys, please kindly answer the following question for me:

1) Does 'cooler capacity' refer to how much food the freezer can freeze in a given amount of time i.e. engine capacity. Basically, when you buy a freezer and it says this freezer can freeze x kg of food in n hours, is that the cooler capacity? Therefore if you put in more then the capacity the freezer does more works so freezing rate is slower?

2) Is product load the current load in the freezer? e.g. if you put in one item and rest of freezer is empty will it freeze fast?
Also If the product load is already frozen then the rate of freezing will be even faster? If however a bunch of new unfrozen food has been put in the rate will be slower?

3) Somebody told me that you can achieve slow freezing by either increasing the product load over the capacity or I believe the capacity over the product load, however the second point doesn't make sense. I can see why if you place a fresh unfrozen load this will decrease freezing rate if it exceeds the capacity, however if the capacity is increased surely it can freeze more at the normal rate? Not sure if I understood the statement correctly. Here is the specialists statement from a previous email can you please explain what he means, especially in the last sentence:

"Temperature alone will assure it only if the capacity of the freezer is very high. If the load is high in a refrigerator situation, it will not be able to maintain the -5C. It can warm even to + tempeatures in order to cool down the product. The rate of freezing depends on the rate of heat removal and hence they are dependent on the cooler capacity and product load. By increasing one over the other you can make it depend either on the cooler capacity or product load."

4) How important is temperature and why, technically speaking, would a high capacity low temperature freezer cause slow freezing?

5) If I need a low temp freezer I could probably hire a laboratory freezer and set it to -5c however since its a lab freezer I'm guessing the rate of freezing maybe fast regardless of set temp?

Anyway guys can you please answer the above questions and also advise me on what I should do step by step in order to solve this problem from home. Should I rent a lab freezer or should I get a bunch of fresh food then stuff it in the freezer etc? WHat do you think I should do in order to slow freeze meat and cause as much ice crystal damage as possible.

Anticipating your reply. Hope you will be able to help. Thanks.

r.bartlett
02-07-2013, 01:28 PM
The slowest way of freezing food it to keep it just below freezing point ie -1. This is irrespective of duty. . A good domestic fridge on it's lowest setting will normally freeze food over time. Try using a domestic fridge set on no/ 5 and see how long it takes to freeze a glass of water.Don't let the cabinet internal temp drop below -4 c throughout the freezing process in order to ensure the chicken within the range you describe. Of course once fully frozen you will need to transfer it to a proper freezer to below -18c if long term storage is required.

The Viking
02-07-2013, 01:37 PM
Ok,
First experiment to slow freeze your meat, over load the freezer..

If you as well as the meat put loads of room tempered water in then the water will act as a heat storage. Depending on what type of freezer you got you could either put a couple of buckets 1/3 full of water in or loads of filled ice-cube bags.
The more water you put in the longer it will take for your freezer to reach setpoint.

:cool:

r.bartlett
02-07-2013, 02:02 PM
Ok,
First experiment to slow freeze your meat, over load the freezer..

If you as well as the meat put loads of room tempered water in then the water will act as a heat storage. Depending on what type of freezer you got you could either put a couple of buckets 1/3 full of water in or loads of filled ice-cube bags.
The more water you put in the longer it will take for your freezer to reach setpoint.

:cool:
This is far too hit and miss IMHO. Once the ice starts to freeze then the cabinet will pull down quicker and quicker. There is no control over -2c to -4 c temperature over the time needed to form the crystals which is the critical issue here.

monkey spanners
02-07-2013, 02:54 PM
I'm assuming you are using a chest freezer with mechanical thermostat. I'd get a digital thermostat and set it to turn off around -3c and back on around -1c. I would wire it in series with the original thermostat which probably controls on evaporator temperature rather than air temperature.
I would program the digital thermostat to have an anti cycle time around 10 minutes.
The temperature probe would want to be in the air in the freezer and away from the walls of the freezer.

Have done something similar with a domestic fridge so it would keep cheese at a suitable temperature.

Segei
02-07-2013, 05:00 PM
Insulate your meat. It will freeze very slowly or it will be spoiled before be frozen:(

hookster
02-07-2013, 07:30 PM
Hi Iceman31
I assume by trying to get ice crystal damage you are trying to get some sort of meat tenderising? or increase the WHC of the meat to increase revenue.
The problem with slow freezing is you will have a high product moisture loss. To reduce this, your meat is blast frozen to seal outer skin then slow frozen at your crystal formation temperature.

Best would be to control refrigeration with a product probe (meat inserted) to maintain core temp at desired temp and utilise a close control setting on a controller.(or multiple depth probes)
Domestic fridges are notoriously bad at maintaining close control around set point. The lack of air flow over product in a domestic fridge gives poor heat transfer rates. defrost design will destroy your aim with the product and increase drip.

increasing heat load in a refrigerator would reduce cooling capacity but this is very hit and miss and you sound like you want to do a far more scientific experiment. I would rent/ build a freezer with product probes, wide fin spacing and a temp range of 0 to -45.

iceman31
02-07-2013, 11:01 PM
Hi Iceman31
I assume by trying to get ice crystal damage you are trying to get some sort of meat tenderising? or increase the WHC of the meat to increase revenue.
The problem with slow freezing is you will have a high product moisture loss. To reduce this, your meat is blast frozen to seal outer skin then slow frozen at your crystal formation temperature.

Best would be to control refrigeration with a product probe (meat inserted) to maintain core temp at desired temp and utilise a close control setting on a controller.(or multiple depth probes)
Domestic fridges are notoriously bad at maintaining close control around set point. The lack of air flow over product in a domestic fridge gives poor heat transfer rates. defrost design will destroy your aim with the product and increase drip.

increasing heat load in a refrigerator would reduce cooling capacity but this is very hit and miss and you sound like you want to do a far more scientific experiment. I would rent/ build a freezer with product probes, wide fin spacing and a temp range of 0 to -45.

Thanks for these replies. I am not looking for meat tenderising and I do WANT MOISTURE LOSS. Actually the more moisture loss the better. However I do not want to do this using a meat dehydrator because not only do I want excessive moisture loss, I also WANT THE ICE CRYSTALS TO RUPTURE THE CELLS, something that can only be achieved using freezing.

Why am I doing this? Well it's a long story and this is not a commercial project. Guys I really need to be able to do this. I am not a freezer engineer or anything like that, just a chronically ill guy who sits at home most of my days. I absolutely need to find out how to do this.

Can you give any more suggestions? How much would it cost to build something like this and is it something I can rent?

Anticipating your reply. Thanks

iceman31
02-07-2013, 11:14 PM
Guys, I also notice nobody has answered the specific questions I asked. Please can somebody do that if possible.

ALso I take it the suggestions are:
1. Overload domestic freezer and hope for the best.
2. Build/buy/rent a freezer which will fluctuate between -1 to -3.
3. Use fridge compartment on lowest setting.

I can try 1 but other say it will probably not work, do you think it is still worth trying?

I have to research/find something that does 2.

A low setting fridge compartment goes to -0 however the freezing point for chicken is -2.2c. Also the bigger ice crystals occur at -3 to -4 so I don't know if a fridge compartment can go that for.

Also, even if we control the temperature, might the freezer not still freeze it fast and bring it up to the required temperature e.g. you put the chicken in and it could be within 3 hours it brings it to -4c which would be too quick?

monkey spanners
02-07-2013, 11:37 PM
1. Won't work or work consistently. (you would have to keep unloading the cold excess stock and replacing it with warm so that the freezer never quite catches up)
2. Depends on your budget, and if you know for sure the process will give you the results you want. (modifying you existing freezer (assuming its a basic mechanical stat model) would be cheaper and prove the concept imo)
3. Could also work well, depends on the amount of product you are hoping to produce a day.

What i'd do i think is get a small cheap table top freezer say £80, then make up a short lead and plug to a box with electronic thermostat in, then run a short lead from the box to a socket. Plug box in wall, plug freezer in socket, put temperature probe from box on freezer. Put chicken in freezer, i'd probably put some water in plastic bottles to increase the load and make the temperature more stable if you are not putting much chicken in.

You could then set the temperature at say -1C for a few hours, then -2C etc etc on the electronic stat.

Expect about £100/£140 in parts to make a box and plug,socket.

May work out easier to hire something if you can, this is not a everyday problem so am just giving it my best guess.

install monkey
02-07-2013, 11:41 PM
Why am I doing this? Well it's a long story and this is not a commercial project. Guys I really need to be able to do this. I am not a freezer engineer or anything like that, just a chronically ill guy who sits at home most of my days. I absolutely need to find out how to do this.


are u a serial killer???- i'm confused to the the ideas of destroying chickens- maybe a blender might help-:off topic:

iceman31
03-07-2013, 12:46 AM
Why am I doing this? Well it's a long story and this is not a commercial project. Guys I really need to be able to do this. I am not a freezer engineer or anything like that, just a chronically ill guy who sits at home most of my days. I absolutely need to find out how to do this.


are u a serial killer???- i'm confused to the the ideas of destroying chickens- maybe a blender might help-:off topic:

No I'm not a serial killer or the like. I will tell you what this is about later but I don't want to make a long story now.

iceman31
03-07-2013, 12:50 AM
1. Won't work or work consistently. (you would have to keep unloading the cold excess stock and replacing it with warm so that the freezer never quite catches up)
2. Depends on your budget, and if you know for sure the process will give you the results you want. (modifying you existing freezer (assuming its a basic mechanical stat model) would be cheaper and prove the concept imo)
3. Could also work well, depends on the amount of product you are hoping to produce a day.

What i'd do i think is get a small cheap table top freezer say £80, then make up a short lead and plug to a box with electronic thermostat in, then run a short lead from the box to a socket. Plug box in wall, plug freezer in socket, put temperature probe from box on freezer. Put chicken in freezer, i'd probably put some water in plastic bottles to increase the load and make the temperature more stable if you are not putting much chicken in.

You could then set the temperature at say -1C for a few hours, then -2C etc etc on the electronic stat.

Expect about £100/£140 in parts to make a box and plug,socket.

May work out easier to hire something if you can, this is not a everyday problem so am just giving it my best guess.

There are some lab freezers which I believe you can set to -1 and below. Would it not be better to rent one of these instead of building one since I believe I can set the temperature on certain lab freezers.

Also even if the lab freezer stays at high temperatures, this doesn't determine the rate of freezing right? For example if you set it to -4c, this is the FINAL equilibrium temp it will reach. As for how fast(rate) of freezing this is dependant on the cooler capacity and load am I correct? Guys this is why I asked all the questions so I can become clear about what is required. I may be wrong but I am guessing controlling the temp alone will not necessarily cause slow freezing.

btw, how much would it cost to pay somebody to build me a small slow freezer as you have described?

Thanks

iceman31
03-07-2013, 12:55 AM
2. Depends on your budget, and if you know for sure the process will give you the results you want. (modifying you existing freezer (assuming its a basic mechanical stat model) would be cheaper and prove the concept imo)
.

Guys, If I asked a professional to come and modify my current freezer so that I could control the temperature how much would it cost roughly? Would any of you be willing to do it?

iceman31
03-07-2013, 12:58 AM
Ok you probably won't as I notice most of you are far from London however, in any case, how much would it roughly cost for somebody to come and do it and where would I find such people? Thanks

NH3LVR
03-07-2013, 02:32 AM
An idea occurred to me a few minutes ago.
I have noticed red stains around the leg bones of fresh chickens before.
I have been told that this was due to bring the temperature down to just freezing during transport, then thawing.
If you want to simulate the ice crystals developing during a slow freeze you could try freezing, partial thawing, then refreezing. I believe this will cause the effect you are looking for.

hookster
03-07-2013, 06:36 AM
It is sounding very complicated for a process to ruin a chicken! just give it to my wife she can do it in 40 minutes :confused:

As NH3LVR says you can program a partial thaw and increase drip from product to reduce moisture.
80% of water can be frozen at the temperature range you are looking for but you will require a lot lower for connective moisture. Then there is increase in bacteria etc at lower freezing temperatures and variance with temperature.

For botulism you will have to refer to my wife again! ;)

I would suggest vacuum cooling as it would be easy to control and dwell time the shortest. Of course this may be out of your budget range but if it is a project of love then a chest freezer could be converted.

It may be worth you giving us your desired outcome description, to see if what you desire can be achieved?

Magoo
03-07-2013, 07:09 AM
Follow the chicken processors method of injecting meat tissue with water and freezer as fast as possible, the water will tenderize the meat as it freezes and expands. Alternatively change the thermostat in domestic freezer for a higher control range. Slow freezing will risk bacteria growth in chicken in particular

r.bartlett
03-07-2013, 07:24 AM
Ok you probably won't as I notice most of you are far from London however, in any case, how much would it roughly cost for somebody to come and do it and where would I find such people? Thanks

cheaper to buy one on ebay...

http://www.ebay.co.uk/itm/All-purpose-STC-1000-Digital-temperature-controller-with-Sensor-thermostat-Relay-/121136254048?pt=UK_Home_Garden_Hearing_Cooling_Air&hash=item1c34488c60

mad fridgie
03-07-2013, 10:28 AM
You leave the freezer as normal, introduce a false load to control the temperture (PID controller, solid state relay and a small heater) I would add a circulation fan (for even temp), there is a good chance your SST will not raise massively, so you will still get your moisture loss. a couple of hundred quid should what you need.

knighty
04-07-2013, 12:54 AM
I think maybe you're just over estimating the damage slow freezing will do ?

I make frozen dog food, and there's times when we've had freezer problems (break downs, high summer temperatures - the reasons I joined here)

I've never noticed any loss of quality in the meat between freezing in a few hours and 24+hours

Magoo
04-07-2013, 02:39 AM
Hi Knighty. No comparison between dog food and chicken production for human consumption. I cannot hover up a ten day old raw road kill and smile and survive and wag my tail. Food safety and bacto counts, salmonella etc., fresh raw chicken chilled has a limited shelf life of minimum hours, only if the process is in-line with health standards requirements

iceman31
04-07-2013, 02:55 PM
An idea occurred to me a few minutes ago.
I have noticed red stains around the leg bones of fresh chickens before.
I have been told that this was due to bring the temperature down to just freezing during transport, then thawing.
If you want to simulate the ice crystals developing during a slow freeze you could try freezing, partial thawing, then refreezing. I believe this will cause the effect you are looking for.

This doesn't work because if the rate of freezing is fast with each freezer attempt, small crystals will grow in the same place. Unless the crystals are big to begin with and there is partial thaw refreeze however you need a slow freeze to begin with.

iceman31
04-07-2013, 03:23 PM
Follow the chicken processors method of injecting meat tissue with water and freezer as fast as possible, the water will tenderize the meat as it freezes and expands. Alternatively change the thermostat in domestic freezer for a higher control range. Slow freezing will risk bacteria growth in chicken in particular

Water injection will put water into the chicken but not into the cells of the chicken. I need the ice crystal to rupture these cells so I need the water inside the cell. As such placing water surrounding the cells won't cause the cells to rupture so i'm guessing.

Also provided the meat is below 0c I'm guessing bacteria will not develop since it's at higher temperatures that bacteria becomes a problem.

danny_s_pike
04-07-2013, 06:49 PM
I would put a small heater with an adjustable thermostat in the chest, giving you a constant, controllable load. After a few test freezes, you should be able to adjust the rate at which the meat freezes. That, to me, would be the easiest and most cost-effective way to get your results.

r.bartlett
04-07-2013, 11:15 PM
I would put a small heater with an adjustable thermostat in the chest, giving you a constant, controllable load. After a few test freezes, you should be able to adjust the rate at which the meat freezes. That, to me, would be the easiest and most cost-effective way to get your results.

Can you expand on how this works, What heaters would you use and how does this constant controllable load work with different amounts of product. What temperature would you expect the freezer to run at and why and how long are you expecting it to take and to what temperature are you goig to freeze the meet?
what is your budget cost approx?

thanks

knighty
05-07-2013, 02:14 AM
Hi Knighty. No comparison between dog food and chicken production for human consumption. I cannot hover up a ten day old raw road kill and smile and survive and wag my tail. Food safety and bacto counts, salmonella etc., fresh raw chicken chilled has a limited shelf life of minimum hours, only if the process is in-line with health standards requirements

eh? no sure where you're coming from there... you've ignored what I said and started to talk about hygiene ?
(also, right now, my government enforced product testing is stricter than for human grade food)

my point was that I've seen all different meats, frozen at all different rates, and I've never experienced a big difference in quality (ignoring flash freezing of course)

those freeze rates including times when we've had a break down and frozen meat very slowly, on mass (and then thrown it away)

so I still think you're over estimating the amount of damage that will occur to the chicken, so you'll never be able to find what you're looking for, because it's not there to be found

knighty
05-07-2013, 02:24 AM
actually, I've re-read what you said

you said "I WANT THE ICE CRYSTALS TO RUPTURE THE CELLS"


but you have it backwards, when slow freezing ice crystals form outside of the cells, water leaves the cells, and the cells shrink

you need to go to -60'C (ish) to rupture cells on mass


there is a slight skin effect, where you can burst the cells on the surface of the meat if you fluctuate the storage temperature of the meat - as the surface defrosts moisture forums, when it refreezes the ice crystals are larget than previously

The MG Pony
05-07-2013, 01:12 PM
why has no one mentioned thermal electric junctions? ie peltiers, control scheme is more complicated but between ebay and a few water cooling shops for pc's he'd have a very percise controle over capacity and temp.

And I will restate, with out knowing what your final goal is we are all just pissing in the wind proverbialy

What is it you are trying to achieve? from there we can make some hard conclusions in the process stream that needs to be designed!

hookster
05-07-2013, 06:51 PM
why has no one mentioned thermal electric junctions?


I guess most of us live in the real world and know that peltier cooling is a waste of time and effort. I always get amazed at some of the applications suggested in this thread :eek:

The idea he has interests us but to be honest what he is trying to achieve is a waste of time with a domestic set up although may be a nice tinker toy! I agree with you though MG Pony for this thread to progress we need expected outcome and maybe even an idea of the size and scale of product to be frozen.

Magoo
06-07-2013, 05:17 AM
Best advise would be to consult your local Food Safety authority, for the handling and processing of chicken meat products. Before you do anything.

The MG Pony
06-07-2013, 04:26 PM
I guess most of us live in the real world and know that peltier cooling is a waste of time and effort :eek:

for any real application you'd be correct, how ever for a test bed to determine the best time and temp it would prove use full.

a couple high powered moduals and a good pwm drive and a precision thermometer he'd have a very tun able freezing box.

danny_s_pike
06-07-2013, 07:34 PM
Can you expand on how this works, What heaters would you use and how does this constant controllable load work with different amounts of product. What temperature would you expect the freezer to run at and why and how long are you expecting it to take and to what temperature are you goig to freeze the meet?
what is your budget cost approx?

thanks

First off, the man has a domestic freezer. He stated that his freezer will not allow him to slow freeze. His goal is to slow freeze. If you put a load in the freezer (ie a domestic, cheap heater), that will make the system work harder, decreasing the freezing capacity of the system. When his poultry is entered into the equation, the freezer must work to freeze the meat and fight the load of the heater at the same time, making freezing times longer.

He did not mention in this thread that he wanted to introduce different amounts of product, so I cannot comment on that part. The temps are posted by the OP, so I will not reiterate.

NiHaoMike
07-07-2013, 04:31 AM
http://www.youtube.com/watch?v=WT_2P7WdKzw
Put a VFD on that freezer and then you can have the PID controller first hold it just above freezing, then slowly drop it at your desired rate. (Set the existing thermostat as low as it goes or bypass it so it doesn't interfere.)

r.bartlett
07-07-2013, 08:47 AM
First off, the man has a domestic freezer. He stated that his freezer will not allow him to slow freeze. His goal is to slow freeze. If you put a load in the freezer (ie a domestic, cheap heater), that will make the system work harder, decreasing the freezing capacity of the system. When his poultry is entered into the equation, the freezer must work to freeze the meat and fight the load of the heater at the same time, making freezing times longer.

He did not mention in this thread that he wanted to introduce different amounts of product, so I cannot comment on that part. The temps are posted by the OP, so I will not reiterate.

how would your system act differently to an adjustable thermostat?

danny_s_pike
07-07-2013, 01:22 PM
how would your system act differently to an adjustable thermostat?

More load=Longer freezing times


NiHaoMike, your VFD idea is a great solution. I have a 350HP screw package that runs on a VFD. Instead of using its slide valve, the compressor will vary its speed. This dramatically reduces power consumption. If he wishes to build a system that will allow him to produce his poultry on a regular basis, this is a good solution IMO.

r.bartlett
07-07-2013, 04:44 PM
More load=Longer freezing times


.

great so walk me through the process. What happens inside the freezer when an excess load is introduced?

danny_s_pike
07-07-2013, 05:36 PM
great so walk me through the process. What happens inside the freezer when an excess load is introduced?

Really? ok, refrigerant is introduced into the evaporator in the freezer. This refrigerant would normally absorb the heat of the product and flash off, carrying with it the heat removed from the product. If excessive load were to be introduced, the refrigerant flowing through the evaporator must absorb more heat, up to the system's maximum design refrigeration capacity. In order to bring the temps down to the desired setpoint, the refrigerant will continue to absorb heat. If there is more load, there is more heat that must be transferred. The system can only work up to its capacity limits, so it will take longer to remove the heat in the freezer.

In my own refrigeration plant, I can tell if a blast freezer has 10 racks of product or 40 racks, by looking at the length of time the system took to go through its freeze cycle.

r.bartlett
07-07-2013, 06:19 PM
Really? ok, refrigerant is introduced into the evaporator in the freezer. This refrigerant would normally absorb the heat of the product and flash off, carrying with it the heat removed from the product. If excessive load were to be introduced, the refrigerant flowing through the evaporator must absorb more heat, up to the system's maximum design refrigeration capacity. In order to bring the temps down to the desired setpoint, the refrigerant will continue to absorb heat. If there is more load, there is more heat that must be transferred. The system can only work up to its capacity limits, so it will take longer to remove the heat in the freezer.

In my own refrigeration plant, I can tell if a blast freezer has 10 racks of product or 40 racks, by looking at the length of time the system took to go through its freeze cycle.

so if I understand you correctly the temperature rises inside the cabinet for an unknown time depending upon how long the system takes to get on top of the product load?

if not please explain in better terms for me to understand

but if so please explain the difference between your solution and raising the set point from -18 to -3 with a 20 dollar stat to simulate the same effect but with greater control of the target products final temperature which was one of the posters critical wants

tia

joe-ice
07-07-2013, 07:08 PM
Is this a fridge /freezer. How about this ,take the feeler of the stat and put it in the freezer compartment.Most of these stats are clamped on the fridge coil so i would imagine their range would be -5 to 10c. Then just control the temp of the freezer compartment itself referencing off a thermometer.ps dont i dont work on domestics so could be wrong about the range

danny_s_pike
07-07-2013, 07:53 PM
so if I understand you correctly the temperature rises inside the cabinet for an unknown time depending upon how long the system takes to get on top of the product load?

if not please explain in better terms for me to understand

but if so please explain the difference between your solution and raising the set point from -18 to -3 with a 20 dollar stat to simulate the same effect but with greater control of the target products final temperature which was one of the posters critical wants

Sorry about that. I don't mean to use the heater to raise the temperature in the freezer. The heater can be used to reduce the cooling capacity of the freezer, thus increasing freezing time. The poster states that he wishes for a slow freeze. I understand that a $20 stat would give you control of the requested temps, but as he stated:

Also even if the lab freezer stays at high temperatures, this doesn't determine the rate of freezing right? For example if you set it to -4c, this is the FINAL equilibrium temp it will reach. As for how fast(rate) of freezing this is dependant on the cooler capacity and load am I correct? Guys this is why I asked all the questions so I can become clear about what is required. I may be wrong but I am guessing controlling the temp alone will not necessarily cause slow freezing.

I just wished to add my .02c. I'm not saying that my idea is a great one and there are far better solutions, just thinking that a chronically ill guy who spends his time at home and who knows very little about refrigeration could try this idea out.

knighty
08-07-2013, 01:34 AM
I was about to say, if you can keep the temp difference between the chicken and the freezer low enough, you could slow freeze (or try to)


but it's all pretty irreverent when no mater how slow he freezes it, it's not going to do what he wants anyway :(

mad fridgie
08-07-2013, 12:13 PM
Fast freezing causes a uniform lattice type ice structure, expansion still occurs and may rupture the cell wall (a bit like a pipe freezing) Slow freezing cause the ice to build somewhat like a snow flake with many edges and points, with penetrates the cell wall in many places.
on defrosting the cell wall become weaker/mis-shaped. The more tears the greater the deterioration.
Unless you freeze dry, removing the internal cell moisture, which seems to make the cell wall more rigid.
it is the deterioration of the cell walls that make frozen food mushy, compared to fresh.

rjsinoz
13-07-2013, 12:06 PM
let some gas out soyou dont let it get below -5 plus without the full gas charge it would take a long time to get to temp

The MG Pony
13-07-2013, 03:44 PM
let some gas out soyou dont let it get below -5 plus without the full gas charge it would take a long time to get to temp

that is incredibly irresponsible and illegal, any refrigerant is to be recovered and handled properly! if that was don back in the R-12 days it wouldn't be banned as it is now. now days you still have idiots venting the stuff guaranteeing that ozone hole stays big n healthy!

rjsinoz
13-07-2013, 05:05 PM
that is incredibly irresponsible and illegal, any refrigerant is to be recovered and handled properly! if that was don back in the R-12 days it wouldn't be banned as it is now. now days you still have idiots venting the stuff guaranteeing that ozone hole stays big n healthy!

hey idiot i dont know how small ur reclaim unit is but mine would cycle off on lp if i tryed to recover the 200 grams in a small chest freezer so a few seconds of letting the gas go is the same as purging your gauge line 20 times, do u do that or are u so worried about the enviroment u just let air enter the system

rjsinoz
13-07-2013, 05:08 PM
oh yeah all the ideas of buying this and installing that also are causing the hole to get bigger by adding a car on the road to get the parts and the manufacture to make more parts only to find out it doesnt work anyways just let 50grams out and ull be right

The MG Pony
13-07-2013, 05:49 PM
I have a standered proper recovery unit, and it does a great job on 16 grams or less, it is not hard at all to properly recover a charge. not hard to make them either to code if you don't one small enough make it!!

As for gauges? I use quality ones with anti-blow back valves, no air in system.

I guess this is the difference between a skilled tech and a non skilled one? One buys the tools and uses them in a way that achieves his goal, rather then finding excuses and cop outs to not do there duties diligently?

and all your excuses still comes down to it is illegal, and I'd report you in an instant had I have more info on you.

monkey spanners
13-07-2013, 06:08 PM
hey idiot

There is no need to take that kind of tone.

rjsinoz
13-07-2013, 06:36 PM
I have a standered proper recovery unit, and it does a great job on 16 grams or less, it is not hard at all to properly recover a charge. not hard to make them either to code if you don't one small enough make it!!

As for gauges? I use quality ones with anti-blow back valves, no air in system.

I guess this is the difference between a skilled tech and a non skilled one? One buys the tools and uses them in a way that achieves his goal, rather then finding excuses and cop outs to not do there duties diligently?

and all your excuses still comes down to it is illegal, and I'd report you in an instant had I have more info on you.

of course you would u sound like a snitch, as for the correct tools i have a cps Recovery Unit which does 10.4 Kg/Hr Vapour its 1 HP and Oil Less cost $3000 AU
thats 174gram a minute so thats 43.5 grams every 25 seconds now considering i would purge the unit due to the large supermarket racks i work on either have co2/r134a or r404a in them, (i would assume the chest freezer has r12 in it maybe r134a) a complete purge of the recovery unit would be required anyways, its internal volume capacity would be about 30-50grams so lets say i lose 15 grams to a purge to ensure no cross contaimination occurs i am fairly confident the unit will cycle off on LP pretty quickly as my compressors efficiency (which does get checked regularly) is correct.
perhaps you should check the piece of crap unit you have and see if its still pumping correctly, unless of course you work on household fridges and only need a slow recovery unit.or of course u dont know how to check it.
as for my gauges i have digital fieldpiece gauges type SMAN4 Digital Manifold 4-Valve which cost $700 AU i also have anti-blow back valves or inline ball valves on mine but due to the ever changing world we live in i am constantly working on different systems with different refrigerants.ie the charge has to come out if there isnt a unit with that gas located near by. then u must purge the line.
maybe you work on one type of unit with the same gas all the time but i am constantly being sent to different systems to service and repair them no install work just breakdowns.
if you think you are so skilled go to this forum and lets here your answer
http://www.refrigeration-engineer.com/forums/showthread.php?39721-saturated-conditions-in-a-receiver-tank-PROVE-ME-WRONG

mad fridgie
13-07-2013, 10:39 PM
let some gas out soyou dont let it get below -5 plus without the full gas charge it would take a long time to get to temp

An absolte no no
Less refrigerant bigger compression ratio very high suction superheat
Lending to a very high discharge temp oil breakdown and comp failure

rjsinoz
14-07-2013, 02:49 AM
yes yes yes
its a little dome compressor who spends it life running in a vacuum with no real heat rejection, ie condensor is in insulation of freezer walls or pushed hard up against a wall in a kitchen,the oil breakdown happens after 1 year of running anyways it will keep on kicking along

mad fridgie
14-07-2013, 03:33 AM
yes yes yes
its a little dome compressor who spends it life running in a vacuum with no real heat rejection, ie condensor is in insulation of freezer walls or pushed hard up against a wall in a kitchen,the oil breakdown happens after 1 year of running anyways it will keep on kicking along

The actual design working pressure is irrelevent by remo inv the refrigerant you increase compression ration
And more of concern is suction superheat increase so your option is totally wrong
Sorry young man

rjsinoz
14-07-2013, 05:00 AM
The actual design working pressure is irrelevent by remo inv the refrigerant you increase compression ration
And more of concern is suction superheat increase so your option is totally wrong
Sorry young man


so why is my chest freezer which holds my beer still running at -2 after a year than old man

mad fridgie
14-07-2013, 06:46 AM
So to hold your beer at -2 you let the refrigerant out or it just a freezer running at high temp

rjsinoz
14-07-2013, 02:07 PM
(to store excess beer, was having a party)
my option on the 40C day was to buy ice and an esky, buy a new fridge from somewhere,put it in the freezer hope my freezer didnt freeze the beer, drink it hot, or as my pissed sparky/electrical mate said cant u just let some gas out of the freezer.
so its a high temping freezer which sometimes freezes my beer, but i do love a cold beer so its all good.

The MG Pony
14-07-2013, 02:27 PM
I am not to sorry to say you have a very poor ethic and attitude to word your chosen career in my not humble opinion.

I do not need to prove any thing, there are various theories of how why and what.

I do multigas systems and so I built a small simple recovery system out of little can compressors just for the small jobs, if your claims are true you surely have the skill to easily make one that will hold up to the codes to do r-134a, R-152a and even R-22 one unit for each, the parts to make a nice compact unit literaly lay out in the street some times! old window aircons give you a lovely prefabricated platform to work with!

So again stope making excuses and cop outs and do your job properly!

that is what seperates us from a parts monkey, we know how to work around a problem well following the rules and regulations!

which are you?

rjsinoz
15-07-2013, 11:25 AM
I am not to sorry to say you have a very poor ethic and attitude to word your chosen career in my not humble opinion.

I do not need to prove any thing, there are various theories of how why and what.

I do multigas systems and so I built a small simple recovery system out of little can compressors just for the small jobs, if your claims are true you surely have the skill to easily make one that will hold up to the codes to do r-134a, R-152a and even R-22 one unit for each, the parts to make a nice compact unit literaly lay out in the street some times! old window aircons give you a lovely prefabricated platform to work with!

So again stope making excuses and cop outs and do your job properly!

that is what seperates us from a parts monkey, we know how to work around a problem well following the rules and regulations!

which are you?

i have a ""oil less" recovery unit, "big Pony" it does all types of refrigerants. plus i work a bare minimum 80hours a week every week, so i dont have time nor the space to carry around 3 different units.thats why i have no probs spending $3000 on a good all round recovery system. which is law here in oz.
i dont even carry enough parts with me to be considered a parts monkey, for that matter.

as for the rules the EPA or arctick governs the trade in oz this is a extract of there rules

please notice number 2 and 4

"Permitted Releases
As is the case for CFC and HCFC refrigerants, only four types of releases of HFCs and PFCs are permitted under the prohibition:

"De minimis" quantities of refrigerant released in the course of making good faith attempts to recapture and recycle or safely dispose of refrigerant.
2.Refrigerants emitted in the course of normal operation of air-conditioning and refrigeration equipment such as from mechanical purging and leaks.
Releases of HFCs and PFCs that are not used as refrigerants (note that heat transfer fluids are considered refrigerants).
4. Small releases of refrigerant that result from purging hoses or from connecting or disconnecting hoses to charge or service appliances.

so as long as i purged my lines while working on the chest freezer and then removed and reattached my gauges a few times in an hour im not breaking any law im just following the rules.
by chance i lose 50grams and the chest freezer sits at -5 or so its all good RIGHT.

and as for the units u make are you taking oil samples to ensure no moisture is present in the compressors, u are finding on the side of the road.
as we would not want acid formation to occur in the recovery unit itself let alone contaminate the recovered refrigerant then place it back in a system, as over here in oz that is illegal and IF I HAD MORE INFO ON YOU I WOULD REPORT U IN A MINUTE. LOL (ah i love our back and fourths)
perhaps thats what seperates good techs to ones like ur self. ie dont be a tight ass and buy the correct tools AND dont make them from scrap you find on the side of a road.

IF anything i should be asking you are u a parts monkey when it comes to maintaining correctly operating tools.
i bet your gauges are over 10 years old too. arent they "big pony"
So for the first time,stop making excuses and cop outs spend some cash and do your job properly!

The MG Pony
15-07-2013, 01:28 PM
we all should strive to lose as little as possible, here in Canada they have the same thing!
bty who said you need to carry them with you? refrigeration is my hobby AND my work, I live it I breath it.

my three stay at home 99% of the time as I rarely bother with small domestic, but a friend in need, or I want parts to play with I can just grab the unit I'll need, now I got gas and parts to play with! here it is 1k for a bottle of recovered R22 (Reprocessed rather)

I got a lovely little oil less unit, and it does a lovely little job, but by using some custom built units I can keep my losses down to the half ounce!

A replaceable core filter drier, a temprite 340 oil sep, a suction line hx and a nice little bar freezer can and you can have a very good little dedicated recovery unit that is pretty light and effective, add some anti-blow back fittings and now you can recover with near 0 loss.

Hope fully others here will see the advantage of the described systems when working on small domestic systems

And no I replace the oil, and ironically yes I do have a 3 stage tester for refrigerant, so go ahead report me, only inconvenience would be to show them my records and offer them a coffee! nice thing when you follow proper protocol and procedure! keeps life simple, just like all ways telling a situation as it is, mean what you say and say what you mean.

So nice attempt but a big fail, as I have both new equipment and custom built equipment with new parts, and old guages yup, they are very good old simple guages built to last, re-calibrated last year, guess you didn't know guages can be tested and calibrated though?

your reminding of the guys in bc, they buy nice big brand new 4*4's and not one of them know how to use it! shiny new tools only offer to make a good techs job easier, they do not make some one a good tech, just a well equiped one ;)

rjsinoz
17-07-2013, 01:51 PM
ah big pony your alright, and really calibrate gauges, ive turned that little flat head screw, so my needle reads zero, haha.
wait was that a trick question????
na i kid i assume you had the pressure display plate reattached or maybe a new link wire to the sector, or do u mean u simply adjusted that screw for the first time. god i hope not or Canada is in some trouble.

you know u remind me of the bloke who taught me. so strict,so by the book, no matter what the situation.
he was old too.... i guess it must be a generation thing.
just for the record i too live and breathe refrigeration i left my house @ 0430 this morning and just got home at 2200 and then went straight to this site.
you see the problem with u old blokes is you under estimate us young blokes, experience doesnt always beat intelligence.
oh yeah im probaly not going to build that unit out of ACRYLIC im just going to buy some wireless temp sensors and install them into an existing system. that way i can get actual temp readings of vapour in a receiver. in a real system.
and i havent forgot to respond to your statement in my forum dont worry im working on something i will provide a youtube link in the coming days, if only the other blokes at the company i work for fixed the units the first time they attended instead of me going back a day or two later i would have had it up earlier.

talk to u soon big pony....

r.bartlett
17-07-2013, 06:13 PM
ah big pony your alright, and really calibrate gauges, ive turned that little flat head screw, so my needle reads zero, haha.
wait was that a trick question????
na i kid i assume you had the pressure display plate reattached or maybe a new link wire to the sector, or do u mean u simply adjusted that screw for the first time. god i hope not or Canada is in some trouble.

you know u remind me of the bloke who taught me. so strict,so by the book, no matter what the situation.
he was old too.... i guess it must be a generation thing.
just for the record i too live and breathe refrigeration i left my house @ 0430 this morning and just got home at 2200 and then went straight to this site.
you see the problem with u old blokes is you under estimate us young blokes, experience doesnt always beat intelligence.
oh yeah im probaly not going to build that unit out of ACRYLIC im just going to buy some wireless temp sensors and install them into an existing system. that way i can get actual temp readings of vapour in a receiver. in a real system.
and i havent forgot to respond to your statement in my forum dont worry im working on something i will provide a youtube link in the coming days, if only the other blokes at the company i work for fixed the units the first time they attended instead of me going back a day or two later i would have had it up earlier.

talk to u soon big pony....

The problem with the internet is that sometimes when a poster writes what he believes is a witty response he can over as a complete prick.

Others here may suggest DT Lacia was of that ilk. He was/is actually quite misunderstood. Not that he couldn't be a prick sometimes as he sure could but generally he was/is an ok guy. If most met him they would probably say the same.

I can only hope for your sake you are of a similar stance(although if you are you probably don’t care for the same reasons as he).

Your arrogance may seem appealing and indeed clever to you but like Lacia's "I'zzz mour cleverer than youse" approach did little to endear him to those he was trying to impress with his substantial knowledge. I fear some may pigeon hole you the same.(again you may not care for the same reasons as he)

FYI His approach to imparting information wasn’t to assist the learner which most ‘normal’ people do for altruistic benefit , rather to belittle those less knowledgeable. To impress on the student, the teacher was –even if only in his own mind- somehow superior because he knew something the student didn’t . It’s a character flaw which sadly is unlikely to change – A Leonard can’t change is spots as they say

Anyway I had planned to keep away from you (as I avoid all Lacia's posts) as I find it all the showboating rather tiresome

I shall leave you to grandstand your response. Good luck btw.

(oh just in case anyone hasn't noticed matey boy has long gone from his thread)

rjsinoz
18-07-2013, 01:21 PM
(oh just in case anyone hasn't noticed matey boy has long gone from his thread)

yeah cause he probably let some gas out of his fridge.....LOL

and dont you worry i am a prick, but every apprentice ive ever had, all tell me, im the best tradesman to work with,
I never talk down to a young bloke who wants to learn and never put **** on them cause they dont know something.
but hey we are all men here "no students" and if a man cant cop someone saying his wrong, well that man sort of sounds like a woman to me.

in saying that.....
maybe you should ask this Lacia out for a drink or romantic dinner as it sort of sounds like u just wanted to post a little story about him......

iceman31
18-09-2013, 05:26 PM
I was about to say, if you can keep the temp difference between the chicken and the freezer low enough, you could slow freeze (or try to)


but it's all pretty irreverent when no mater how slow he freezes it, it's not going to do what he wants anyway :(

Why would it not do what I want? Ice crystals expand when the chicken is between range -2.2c to -4c. -2.2c is the initial freezing point. If the chicken spends a few hours here it won't be enough however if it spends several hours to a day then im guessing It would work. What makes you say It wouldn't work?

Thanks