There are things you can live without, but when they appear in the house, they make life so much easier that they become irreplaceable and necessary. This concerns a useful invention - a cold accumulator.
Cold accumulator: properties and application
A cold accumulator is a small device whose main function is to maintain a cold temperature for a long time. The battery design is simple: a tightly closed container filled with a substance with high heat capacity, that is, the ability to absorb heat, thereby cooling objects.
Using a cold accumulator is very convenient and effective at dachas and in camping conditions. They perfectly retain cold in cooler bags as a cooling component. Manufacturers advise using 1 standard battery per 15 liters of cooling product volume, but to effectively preserve cold it is better to use 2-3 containers.
And in home stationary conditions, you can successfully use the battery to save energy by placing it in the freezer and thereby maintaining a stable temperature in it, and even increasing the freezing power. The batteries will also serve in the event of hygienic defrosting of the refrigerator.
If there are problems with electricity, the battery will help preserve food until the problem with electricity is resolved.
Industrial cold accumulators are used in the sale of frozen products and in the transportation of products that have perishable properties.
Preparation and action
It is not difficult to prepare a cold accumulator for use. The containers are placed in the freezer, turning on the maximum cooling mode, for the time necessary to completely freeze the liquid. Freezing time directly depends on the type of filler. You can then use it in an isometric bag throughout the day, the battery will take heat from the food, keeping it fresh.
The useful life of the battery depends on several factors:
- battery type;
- insulating properties and volume of the bag;
- rationality of placement;
- initial temperature of the products.
Depending on the size of the bag, you may need several batteries. It is very important to place them correctly in the space of the bag:
- can be placed on top of provisions;
- arrange horizontally in layers;
- place above and below.
As the composition in the battery container defrosts, it is removed from the bag, washed with water, wiped dry and placed back in the freezer.
It is necessary to store the cold accumulator in the refrigerator when it is not in use, this ensures the safety of the accumulator and increases the life of the refrigeration-freezer device.
Types of cold accumulators
The design features of cold storage batteries depend on its purpose. Most often they are rectangular and flat, which ensures good contact and fit. The shell is made of a hard, strong polymer that does not change its shape or of a dense plastic film, which makes it possible to give the battery the desired shape before freezing.
Manufacturers most often produce three main types of cold storage batteries, depending on the filler:
- gel;
- water-salt;
- silicone.
Gel battery - a package with a gel filler based on carboxymethylcellulose, used for dual purposes, as a cooling element and an element capable of maintaining, if necessary, high temperature. The useful time is long. Safe and effective.
The water-salt type of cold accumulator in hard plastic containers is capable of maintaining temperatures from -20 to +8 degrees Celsius. It is convenient because you can add solution to the container.
Silicone is a film bag filled with silicone. Despite the fact that the temperature of its composition is in the range from 0 to +2 degrees Celsius, the duration of maintaining this temperature regime can reach up to seven days.
Choosing the right battery
When choosing a cold storage battery, it is important to consider that the characteristic blue does not have any functional properties: the dye has this effect. The lifespan of industrially manufactured batteries is unlimited. Manufacturers guarantee environmental friendliness and safety of materials that do not change their characteristics depending on time and sudden temperature fluctuations. Typically, the capacity of a standard battery is 250-800 ml.
When choosing a battery for your needs, take into account its parameters: volume, design, filler composition.
DIY battery
Batteries can be purchased in specialized stores, placed an order on online resources, but you can make it yourself, according to the “cheap and cheerful” principle. Of course, the key point is the composition of the liquid that is used as a filler for a plastic container. In industrial batteries, the coolant contains: water, an antibacterial additive and carboxymethylcellulose. The latter serves as a thickener and controls the expansion of water when freezing.
Considering the above, we offer several recipes for preparing liquid for a homemade cold accumulator.
Recipe No. 1
Manufacturing process:
- in a liter of regular drinking water, preferably warm, prepare a saturated solution of table salt, adding about 400 grams of sodium chloride (table salt);
- add three liters of water to the composition and add the required amount of wallpaper glue. The consistency of the liquid should be gel-like;
- pour the solution into plastic containers with a screw cap or plastic bottles;
- place in the freezer and freeze.
Such a battery can maintain the temperature in a special bag down to -20 degrees C for a long time.
Recipe No. 2
For a homemade cold accumulator: you need to prepare a 20% solution Glauber's salt. For 100 grams of solution, you need to use the following ratio of substances: 20 grams of anhydrous salt, 1 gram of CMC (wallpaper glue) and a certain amount of water.
This battery composition is capable of maintaining cold temperatures down to -10 degrees C.
Recipe No. 3
This is the simplest, one might say force majeure, method of making a cold accumulator. It is necessary to mix water and wallpaper glue in the following proportions: 96 grams + 4 grams.
Minus 1 degree Celsius in a bag of groceries can create refrigerator conditions and allow you to hold out for some time.
At home, it is difficult to maintain tightness requirements, so special attention When using homemade cold storage batteries, you need to pay attention to safety, especially if they are planned to be used for cooling food.
Video about preparing a cold accumulator
Cold accumulators are a very convenient device, indispensable on a hike or a long trip. They for a long time preserve food and prevent it from spoiling during the hot season. A cold accumulator is a small flat sealed container filled with a special compound that freezes quickly. Such a reusable device allows not only cooling, but also storing cold in car refrigerators and insulated bags. For a cooler bag, a cold accumulator is used as the main cooling element.
Types of cold accumulatorsCurrently, three types of cold batteries are produced: gel, water-salt and silicone. They differ according to the type of filler. The gel cooler is made of a dense film with a special gel inside. It can both maintain a lower temperature and keep it elevated. A water-salt battery is a plastic container with a saline solution that maintains a temperature ranging from -20°C to +8°C. A silicone cooler is a package made of durable plastic film filled with silicone. Such a battery maintains a temperature of 0-2°C, but for a long period (up to 7 days). This is its advantage over the other two types of coolers.
How to use a cold accumulator?
As a rule, the cold accumulator works very simply. Before use, it must be placed in the freezer for a long time to completely freeze the filler inside the device. After that, put it in an isometric bag and the battery will keep the cold for about 20 hours (depending on the model of the bag), taking heat from the products in the bag. Then the cold accumulator needs to be washed with water and put back in the cold. The cold accumulator for the cooler bag is made from environmentally friendly materials that are absolutely harmless to food products. You can store such batteries in the freezer compartment of the refrigerator or in another place protected from light. The service life of these devices is unlimited if stored correctly. Depending on the size of your cooler bag and the amount of food in it, you may need more than one battery. If you are using one cooler, then place it on top of the food, and if there are several, then layer everything in the bag with them, and place another one on top.
Cold storage batteries are also used in household ones. They stabilize the freezer compartment of the refrigerator, thereby facilitating the compressor to turn on and off more rarely. In addition, the cold accumulator increases the time for safe storage of food if there is a power outage and the refrigerator does not work. The freezer will still remain at sub-zero temperatures until approximately 6 p.m. This device also increases the freezing power in freezers. When manually defrosting a refrigerator, it is very convenient to use cold storage tanks.
Cold accumulators are used in thermal chambers when selling ice cream or during the transportation of perishable food products.
How to choose a cold storage battery?
Today, stores offer a fairly large selection of cold storage batteries from various manufacturers. Devices with a gel-like filler are very popular - they retain cold longer and do not defrost. In addition, you should pay attention to what the container itself is made of: whether it will leak during use. Cold accumulators are manufactured in the most various volumes: from 250 ml to 800 ml and more. Therefore, depending on your needs, you can select the required number of cold storage tanks, then your supplies will not be afraid of the heat, and you can safely go on a trip.
Cold accumulators are cooling elements that can maintain a low (warm) temperature in a special bag or container. Such sources are irreplaceable during hikes and during transportation. medicines, vaccines that require temperature control.
The cold accumulator is a plastic sealed container, inside of which there is a special substance. The filler can be:
- gel;
- salt water;
- silicone-containing composition.
When choosing a device, you need to focus on the size of the bag that is supposed to be used for storing refrigerated or frozen products, and take into account the features of the specific type of filler.
The most important element in storage units, the “filling” is considered, since it is its properties that determine whether the food will remain fresh or not. There are several types of cold accumulators sold in stores: some of them are recommended for use for hot products, others for cold ones, and others for frozen ones.
Properties of cold sources
For the production of the storage devices in question, only safe polymer materials that do not threaten human health are used. The capacity of magazine devices is generally from 0.25 to 0.8 liters.
The use of a film surface allows you to give sources that have not yet frozen the desired shape. In addition, temperature changes do not have a negative impact on them.
The outer part of the gel devices is made of film, and the substance of the same name, which has high thermal conductivity, is used as a filler.
The use of gel cold sources allows you to create an area of low temperatures (inside the container, bag), as well as maintain a certain temperature of the products, so that they can remain warm longer.
Carboxymethylcellulose, which is a gel-forming substance, in case of damage to the film and accidental contact with food or medicine, does not spoil them and does not have a negative effect on the human body.
Salt storage tanks are distinguished by their ability to maintain temperatures within the range from -20 to +8 degrees. However, they are not suitable for long-term storage, since their charge only lasts for a day. The outer part is hard and made of plastic. Inside the container is an aqueous solution of salt.
When choosing water-salt devices, you need to remember that the seal of the plastic container may be broken, and the liquid may leak into the bag and thereby spoil the food.
A silicone cold storage battery has a number of advantages: the material used for its manufacture is quite durable, and the filler contains polymers containing silicon crystals. The temperature in the bag when using storage devices of this type remains within the range of 0 to 2 degrees for quite a long time (up to 160 hours).
If you are planning a long trip, as well as transporting perishable foods and medicines, the storage of which is possible only at certain temperatures, preference should be given to more reliable sources. If necessary, you can put several drives in one bag.
How to use cold accumulators
The operating principle of the devices in question is the same for all types of batteries. They need to be “charged” before use. For this purpose, the element should be placed in the freezer and left there for about 8 hours (until completely frozen).
If the gel source is to be used as a heater, it must first be “charged” with heat in a microwave oven.
Long-term storage of the battery at low temperatures does not damage it. On the contrary, while the element in question is not in use, it is better to keep it in the freezer of the refrigerator. Constant temperature, as well as less frequent recharging, can extend the service life of the element.
After the cold supply has been used up, the device must be thoroughly rinsed with water, dried and placed in the freezer. It is advisable to carry out this procedure after each use, since the surface of the battery becomes dirty due to the condensation that forms, and due to its close proximity to food, it can become saturated with various odors.
Alternative to factory batteries
Do-it-yourself cold storage devices are, of course, inferior in properties to factory-made devices. But, if the planned trip does not take much time, they can be quite useful.
The simplest option for a cold source at home is frozen water in a bottle (both plastic and glass will do). This type of battery has a big drawback: the ice melts quickly, as a result of which the low temperature in the insulated bag does not last long. The best performance of a homemade invention can be achieved by adding salt or alcohol to the water.
So, the materials at hand needed to make a cold storage tank:
- plastic bottle;
- water;
- salt or alcohol.
The approximate ratio of the last two is 10:3 (for example, 100 g of water and 30 g of salt). The freezing point of such a liquid is about -20 degrees. If it does not freeze for a long time, you need to drain a little of the solution and add clean water.
Thermal conductivity of concentrated aqueous solution salt is approximately equal to 236 kJ/kg. This value is not a limit: it can be increased, but the freezing temperature of the composition will decrease.
If you add wallpaper glue or gelatin to the salt solution (the consistency of the solution should be similar to a gel), the resulting battery will melt more slowly compared to previous versions of the devices. For greater efficiency, homemade batteries should be placed at the bottom of the bag and on top of its contents. If necessary, you can additionally place them between products.
The composition of fillers in factory batteries is determined using special formulas. Therefore, the parameters of such devices differ significantly from home inventions. However, homemade batteries can be useful in cases where there is no factory-made device, but you need to travel and carry groceries or medicine.
Where can you use a cold accumulator?
There are also cold sources used as trays. Food and drinks placed on them are either cooled or remain warm longer.
Cold storage units are also indispensable in the event of a power outage. The elements in the freezer or refrigerator release the accumulated cold, thereby slowing down the defrosting process for one day.
Cold accumulators in the freezer are needed not only in emergencies, but also on ordinary days. Their presence leads to an increase in the degree of freezing of products placed in the chamber.
When choosing a cooling element, you first need to answer the questions for what purposes it will be used and how long the device will operate. Only after this will it be clear whether a factory-made (gel, silicone, water-salt) or home-made cooling element is needed.
Any cooler bag, regardless of size and purpose, works on the principle of a thermos. That is, its walls simply do not allow heat to get inside from the outside environment, thereby keeping the contents cold and preventing it from deteriorating. To increase the effectiveness of this device, several bottles of frozen water are sometimes placed inside. After all, heat, although slowly, still comes from outside, and so that the food does not have time to heat up, the ice cools them at the same time. Such a bottle is the simplest cold accumulator, created at home from improvised materials. Ice in a bottle has one huge disadvantage - it melts quite quickly, the water heats up and the system becomes less effective.
How to Improve Your Cooling System EfficiencyIn order for cold storage batteries to maintain a low temperature in the system longer, you need to use another liquid with a higher level of heat capacity instead of water. On the other hand, if it is poured into ordinary plastic bottles, it can get inside the bag and onto its contents. Therefore, when it comes to storing and cooling food, in addition to heat capacity, another requirement is added - safety.
Since it is quite difficult to create a sealed container at home, it is better to count not on the fact that the liquid will not spill, but on the fact that it will be harmless even if accidentally consumed. So, at home, a cold accumulator can be made using ordinary water and table salt. If you mix them, you get a substance with a higher heat capacity than ordinary water, and if it gets on food, the maximum that threatens it is to become wet and over-salted.
Cold storage batteries on sale
For those who are not satisfied with salt water in bottles, there are special, hermetically sealed, plastic vessels, inside of which there is a non-toxic liquid with a high heat capacity. Buying them is simple - this can be done in any supermarket or store specializing in the sale of goods for tourism and travel. The cost of such a bottle is low, so instead of creating a chemical laboratory in the kitchen, it is easier to purchase a ready-made cold accumulator. However, the manufacturers do not indicate its composition. But, firstly, it is written that the liquid is non-toxic, secondly, it is hermetically sealed in the vessel, and, thirdly, its shape allows you to save space when placed in a square-shaped box or bag.
If you are planning a trip or hike in the morning and need to take a refrigerator, the containers should be placed in the freezer in the evening. By morning the liquid will freeze and the cold accumulator will be ready for use. You just need to place it in a cooler bag, a box with thick walls, or even in a regular bag (this will ensure minimal efficiency, but it will still heat up more slowly than usual). As a rule, manufacturers recommend using 1 battery per 15 liters of volume, but from practice we can say that it is better to take 2-3 pieces. In addition to cooling food and drinks while traveling, such batteries have another application - they perfectly stabilize the temperature while in a regular refrigerator. And, of course, there are industrial
We got our hands on the Technology Demonstrator (Proof of Concept).
Previous studies on concentrations -
I used a saline solution as a basis (the container is supposed to be corrosion-resistant).
Three 200 ml jars, filled with 150 ml of water,
We add nothing to the first, two teaspoons of salt to the second (about 20g), and three to the third (about 30g).
The precision scales died (someone washed them), so everything is done by eye.
It turns out to be approximately 0, 133 and 200 g/kg, the table freezing temperatures are approximately 0, -8 and -13 degrees, respectively.
In 5 hours, the first jar (without salt) froze by ~90%, the second and third - about 10% and 5%.
Overnight, the first two jars froze, the third - by ~90%.
The third froze completely for almost a day.
The pulled out jars sweat and the dew on them freezes, but on jar #1 (with pure ice) it melts after a while, and #2 and #3 remain covered with frost (nice).
Conclusion - the optimal concentration depends on the intended use.
With a high concentration they give a lower temperature (they “freeze” better), but they also “charge” longer.
It may not be possible to “charge” above 200g/l.
On the Internet you come across a recipe for “six tablespoons per 1 liter of water” - this is 150..180 g/l (according to the reference book - without a slide - 25 g, with a slide - 30 g), in my opinion, based on the result of the experiment, it is a bit too much.
I also found a recommendation to make a gel with carboxymethylcellulose (http://forum.ixbt.com/post.cgi?id=print:64:1712), which is CMC and wallpaper glue.
There is a certain reason - even with the eye you can see that the solution tries to separate when freezing/thawing (when shaken into the light, you can see the movement of liquid with different fractures/densities).
But for one-time crafts and use with a thermal bag there is no point - shaking is easy.
Another substance for use in cold storage batteries is glycerin.
Freezing point depending on concentration:
Attention! Judging by Russian-language sources (http://ru-safety.info/static/pngbig/307585170.png, http://www.tmbhim.ru/glycerine5.html) the figure in the table is massive share.
It makes sense if only corrosion-resistant containers are available.
Well, let’s remember the parameters for salt and IPA:
The salinity (S) of water is measured as grams salt per kilogram of water, and the freezing temperatures are as follows.
S (g/kg) 123 140 193 212 231 250 269 290 311 353
T (°C) −7.8 −9.1 −13.2 −14.6 −16.2 −17.8 −19.4 −21.1 −17.3 −2.7
Attention!!! Here massive concentration.
2. Isopropyl alcohol solution (IPA):
Freezing Point of Isopropanol (2-Propanol) based Water SolutionsFreezing Point
Isopropanol Concentration
(% by volume) 0 10 20 30 40 50 60 70 80 90 100
Temperature oC 0 -4 -7 -15 -18 -21 -23 -29 -37 -57 -73
Attention!!! Here VOLUMETRIC concentration.
