You've probably heard about gravity convection, mechanical convection, safety, and vacuum ovens. These ovens are staples in a laboratory. Other than drying, these ovens are suitable for many other things, like sterilization, annealing, burn-in testing, and incubation.
Contact us to discuss your requirements of Vacuum Drying Machine. Our experienced sales team can help you identify the options that best suit your needs.
For the best drying oven, a vacuum drying oven is an excellent choice because it is versatile. It's ideal for a wide variety of applications, from plant drying to battery production. Thus, it's a good investment for your lab because you don't have to buy multiple pieces of equipment to perform different processes – you only need a vacuum oven.
Keep reading to learn what a vacuum oven is, what it is for, and its advantages.
What is a vacuum oven?
A lab vacuum oven is a piece of equipment that effectively removes moisture, gas, and other chemicals from a substance without oxidation or other unwanted reactions. Other ovens often perform combustion processes to achieve desired results. But with a vacuum oven, the vacuum chamber reduces pressure and boiling point while evaporating unnecessary substances even at low temperatures.
Here are some distinguishing features of a drying oven:
1. It uses dry air to remove humidity. This lab oven is routinely utilized to evaporate combustible liquids or small and dry substances.
2. Vacuum ovens feature an exhause port that vents moisture away from the materials for drying and function at relatively low temperatures. Moreover, the oven's low-pressure interior lowers the temperature at which liquid water turns into a gas.
3. These ovens can operate at temperatures of up to 250°C.
What are vacuum drying ovens used for?
1. Moisture Removal
Vacuum ovens remove moisture at low temperatures because of the low pressure inside the chamber. As such, they're ideal for materials that are highly combustible or are sensitive to high heat. Vacuum ovens are typically used to eliminate extra moisture or to dry fragile items like microchips and medical equipment, usually at the last production stage.
2. Off-Gassing
Off-gassing, also known as out-gassing, is a process that involves expelling all the toxic chemicals from the surface of metallic materials. A vacuum oven makes this process easier since all it takes is placing the object inside the heating chamber and setting the temperature.
The oven removes moisture and other unnecessary chemicals from the material that sealants and lubricants may have left behind. Getting rid of these moisture sources is crucial because they may interfere with the object's performance and usability.
3. Chemical Reaction Prevention
A vacuum drying oven gives you more control over what happens inside the chamber compared to other types of lab ovens. Since it operates at low temperature and pressure, it gives you more leeway to adjust these variables to trigger the required chemical reaction. Having this level of control also significantly affects the quality of the final product and may save more time in certain situations.
For example, because of the low temperature, vacuum ovens make it easier to protect metallic objects from oxidation. You can also add vacuum pressure controllers and other accessories to optimize the drying process further.
4. Annealing
Annealing alters the physical and chemical properties of a material by exposing it to high temperatures. This process reduces the material’s hardness, ductility, or malleability and makes it more workable.
In the annealing process, the parts are heated and then progressively cooled to achieve a softer structure and to improve the material structure for the subsequent shaping procedures.
A vacuum oven is ideal for annealing because it provides the following benefits: avoiding intergranular oxidation (IGO) and surface oxidation, avoiding decarburized areas, cleaning surfaces of parts after heat treatment, and eliminating the need for cleaning of parts.
Advantages of Vacuum Ovens
1. You can safely dry and heat thermosensitive substances like powers and other granular materials in vacuum ovens.
2. Vacuum ovens do not emit toxic chemicals that can harm lab employees.
3. In typical ovens, thermal explosions may be a concern. However, since vacuum conditons rule this equipment's system, the chances of thermal explosions are slim to none.
4. Materials dry faster and more uniformly in a vacuum oven because of the lack of humidity inside the chamber.
5. They are more energy-efficient compared to other lab ovens that use high temperatures for drying.
6. You can expect the same output quality among different batches of items because of the oven's consistently uniform drying method. This makes vacuum ovens reliable for heating multiple batches of samples.
Level Up Your Drying Procedures with Across International Drying Ovens
Lab ovens cater to different purposes. But if you want a versatile oven that can dry, anneal, off-gas, and prevent unnecessary chemical reactions in your materials, a vacuum drying oven is the best choice. It allows you to heat multiple batches of samples and thermosensitive materials while keeping your energy costs low.
Our vacuum ovens can achieve maximum temperatures of 220°C, with high-temperature models reaching up to 350°C and 500°C. They also feature an independent vacuum, purge needle valves, and a radiant warm-wall heating system to ensure an efficient and uniform drying process. Their two control configurations and display options make them easy to use, even for new lab workers who are not thoroughly familiar with the industry.
Remember to buy only from trusted lab equipment manufacturers if you plan to invest in a vacuum drying oven. Across International has over 30 years of experience providing a wide range of lab ovens, including vacuum ovens.
Check out Across International's line of vacuum drying ovens today.
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The modern technology applied in the wood workshops has resulted in the optimisation of the use and machining times of the raw materials.
However to try and save 0.5 mm on the thickness of a plank or 1 m. a second in the speed of a machine tool without paying the same attention to the “non quality” of the drying operation, can cause losses in yield of between 5 to 10% on the aforementioned machines.
The drier must therefore be considered as a machine which is part of production, guaranteeing a real saving on the raw material and on the quality of the finished product.
The ISVE EM dryers are particularly suitable for drying boards using various types of wood.
They are called “dry kilns with continuous/discontinuous vacuum” because the vacuum phase can be interrupted by hot and humid air cycles allowing quick heating of the wood. In order to achieve optimal results the wood must be heated gradually and homogeneously.
In our EM, the pile is made of listeled boards which are placed on the carriage of the autoclave. The drying cycle starts when you close the machine and set all parameters on the computer.
The reduced sizes compared with the productivity of these units produce noticeable saving in terms of space and in terms of easy housing on the company premises without the need for any special brickwork or connections.
The quality materials used in the construction of the autoclave, such as stainless steel and aluminium, guarantee a long resistance against corrosion, whereas the choice of components from leading Italian and foreign companies means they are able to attain a high level of reliability.
These characteristics, common to all ISVE dryers, result in very high quality drying, short working times with reduced operating costs.
FROM TOStack sizes m3275Internal lenght m.518Power kW1065Weight Kg1.10015.200SEE ALL MODELS
Heat diffusion system of ISVE EM dryer series
In a first phase, hot air with a high content of humidity circulates in the autoclave.
At the beginning of the cycle, it is very important to gradually increase the wood temperature avoiding the beginning of drying of the board upper part. The humidity high value which is electronically controlled by probes, hinders some dangerous strains along the wood from taking place.
Once the temperature value of the pile has reached the required level, the vacuum pump eject air from the autoclave. When the fixed vacuum value is reached, the accumulated heating causes the evaporation of the water from the boards causing its drying.
These phases often take place during the process, mixing hot and humid air with vacuum which is an essential factor for a quick and good drying.
Loading carriage with pile of boards ready to be charged in the autoclave
How to choose a vacuum dryer, but above all how to calculate its size according to one’s requirements?
The main parameters to be taken into consideration are as the follows:
From the graphic below, some indications of the drying times on the basis of initial humidity level and thickness of wood can be had.
By centring the initial humidity level of the boards with the vertical line of the thickness and then by moving down to where the whitish-grey lines of the different types of wood are crossed, the duration of the drying process, expressed in days, can be set.
From this result it is easy to see how the reduction in drying times means smaller capacity driers can be used compared with the volume of wood to be dried.
They range from saving space to easier insertion in the company drying process logistics.
Last but not least, the monolithic characteristics of ISVE dryers permits an easy re-positioning in case is required a change in the company production line.
The drying and design’s quality are two important features of ISVE EMV dryers, making them simple to use and easy to insert in the company production cycle.
Drying of wood by exposing it to the open air or when using traditional dryers always have the following processes:
If the two processes are not carried out in perfect harmony, abnormal tensions may be created (PHASE 3) causing warping and cracking of the wood.
The reliability of a traditional drying system is therefore linked to the need to use rather long process times in order not to create differences in humidity within the same area to be dried.
This process is however valid for lowering the water content in green wood.
Drying by a vacuum process makes it possible to apply two natural physical principles:
The first principle guarantees rapid removal of the water vapour starting from the centre of the wood mass and a drastic reduction in thermal energy requirements, as the operation is carried out at low temperatures.
The second principle allows to control and regulate the amount of humidity removed from the wood, second by second, by regulating the temperature of the condensers.
The synergy of the two processes enables the humidity in the wood to be lowered uniformly and without stress.
Considering the high technology applied to these machines and the possibility of being able to adjust each process phase very precisely, drying in a vacuum is very suitable for establishing a definite percentage level of humidity in the wood.
This result is of the utmost importance, especially and above all during the later finishing and assembly phases of the semi-finished product.
In the case of wood which has cavities of resin, vacuum drying also guarantees the complete evaporation of vegetable solvents, thus causing an irreversible crystallization of the resin itself.
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