The oven is infrared electric. Infrared oven for sauna. Let's understand the terminology

The owners of the patent RU 2304884:

The invention relates to the food industry, everyday life and public catering, namely the production of food products, including meat products. The oven consists of a housing with insulation, a working chamber, a viewing window made of heat-resistant glass to monitor the readiness of the product, upper IR emitters installed in a device for adjusting its position, lower IR emitters installed permanently, a hearth installed in grooves built into side walls of the working chamber, for fixing the distance from the emitters of the product to the object, the mode controller or the power supply voltage regulator. There is a timer on the oven panel. The technical result is the simplicity of design, the oven can be used both in the field of catering and in everyday life, not only for cooking culinary dishes, but also for heating ready-made meals. 1 ill., 1 tab.

The invention relates to the food industry, everyday life and public catering, namely the production of food products, including meat products.

A device for thermal processing of food products is known, comprising mechanically interconnected upper and lower parts with supporting elements for installation on a horizontal surface and placed in the upper part of the source of infrared radiation, the upper part is made in the form of a closed chamber, on one side of which windows are made for transmittance of the source radiation, while the upper and lower parts are connected to each other by means of vertical racks fixed on the lower part, relative to which the upper part is installed with the possibility of moving in the vertical direction, turning around the horizontal axis and fixing, and the lower part is made with ledges for installation on them utensils for processed products .

The disadvantage of this device is the bulkiness and complexity of the design.

At present, a series of microwave ovens from various manufacturers have become widespread, and the market is flooded with various ovens that use various types of heating.

Known microwave oven of the German company "Bork" for the heat treatment of food products in a combined mode: exposure to microwaves and infrared radiation, "grill" mode, mesh round stand, rotary function switch.

The disadvantage of this furnace is the slow heating of the product, since the emitters are located in the corner of the upper part of the body under the grid, with this method, the product is heated very slowly, unevenly, since the emitters are under the grid, which reduces the radiation intensity, the "grill" mode is practical for thin-layer meat products, cutlets, chicken wings.

There is also known a method of heat treatment of food products in a Ferrete microwave oven, in the same way as in the description of the method of heat treatment in the second case, meat products are placed on a grill grate, this oven also has a "grill" mode, in which electricity is supplied only to the heating element, the use of power at 100, 80, 60, 40% is provided.

The disadvantage of this device is the slow heating of the product, as in the second case, the emitters are located in the corner of the upper part of the body under the grid, which reduces the radiation intensity due to reflection from the surface and leads to the creation of an uneven radiant flux over the entire surface of the product, as a result which is inevitable local overheating and burns of the product, also this method is intended and practical only for thin layers of meat, steaks, chops, chicken sausages

The invention is aimed at eliminating these disadvantages.

To do this, in a chamber-type IR oven for thermal processing of food products with IR radiation, including a housing with insulation, a working chamber, a viewing window made of heat-resistant glass, IR emitters, a mode controller, under, according to the invention, IR emitters are installed horizontally in the upper and lower parts of the chamber, with the lower IR emitters installed permanently, and the upper ones with the possibility of adjusting the distance to the product using a device for automatically adjusting the position of the emitter, which is a collapsible structure, and the distance to the lower IR emitters is regulated by installing the hearth on the grooves intended for this, built-in on the side walls of the chamber, and the lower IR emitters, depending on the product being processed, can be turned off using the mode control.

The novelty of this device lies in the simplicity of design, small-sized, desktop chamber type, it can be used both in the field of catering and in everyday life, not only for cooking culinary dishes, but also for heating ready-made dishes, for some types of culinary products, including and meat, modes have been developed that are set in the oven using a mode controller with software, as well as an automatic control device for IR emitters, the oven is equipped with hearths of various configurations and from various materials: ceramic (of different thicknesses, the optimal thickness of the ceramic hearth was selected by the method of a planned experiment) , mesh and solid metal, porcelain.

The authors, based on previously obtained results and their personal experimental studies, directed the task of the invention to the development of methods for thermal exposure and a device in which these methods can be implemented. In the proposed device, meat products retain their nutritional value and, in comparison with the known high organoleptic, taste and beneficial properties for humans, which persist for a long time. A simple and economical method of heat treatment of not only meat products, but also various other products, as well as a device for implementing the proposed methods is proposed.

The technological cycle for the production of food products, including meat products, includes heat treatment of the product with infrared rays, in which infrared emitters are built in on both sides in the upper and lower parts of the chamber-type oven body without protective devices, due to saving energy consumption for protective devices, since some of the energy is spent on heating the protective devices.

Heat treatment can be carried out on various baking trays or hearths of various configurations and from various materials: ceramic (of various thicknesses), porcelain, mesh, solid metal.

The invention is illustrated in the drawing, which shows the view of the furnace in frontal section.

The oven consists of a housing 1 with insulation 2, a working chamber 3, a viewing window made of heat-resistant glass (not shown) for monitoring the readiness of the product, upper IR emitters 4 installed in the device 5 to control its position, lower IR emitters 6 installed stationary, hearth 7, installed in grooves 8, built-in on the side walls of the working chamber 3, to fix the distance from the emitters of the product to the object 9, the mode controller or the power supply voltage regulator (not shown), a timer is provided on the oven panel

The oven works as follows.

Depending on the product being processed, the processing mode is determined using the mode controller. Open the door. Using a device for automatically adjusting the position of the emitters 5, the distance between the upper IR emitters 4 is set. The processing object is placed on the under 7 and placed in the working chamber 3 in the grooves 8 at a distance from the lower IR emitters 6, depending on the selected mode. Close the door, turn on the mode controller and the timer and perform heat treatment. In the process of heat treatment, depending on the mode in the furnace, it is provided to turn off the lower emitters using the mode controller. The readiness of the product is determined either visually or in accordance with the worked out modes by turning off the timer.

The quality of the meat processed in the proposed oven had high organoleptic characteristics and a fairly high nutritional value, which is confirmed by analyzes of the amino acid composition compared to cooking carried out in known microwave ovens, which confirms the advantages of the proposed device and the proposed modes.

For the manufacture of certain products on an industrial scale, when it is necessary to make the most of the heat obtained in the combustion process, it is used tunnel kiln.

At many enterprises, for the manufacture of certain types of products, processing at different temperatures is necessary. Modern technologies make it possible to distinguish zones with different temperature conditions in tunnel kilns, which in turn simplifies production.

Areas of application of thermotunnels.

The designs of thermal tunnels are constantly being improved, but the principle of operation remains unchanged. Most of them are widely used in many industrial fields.

• Drying of confectionery products, including refined sugar.
• Bakery and confectionery products.
• Manufacture of building and ceramic products.

Recently, thermal tunnels have been used for packaging of various products in shrink film.

The principle of such packaging is quite simple. Under the influence of high temperature, the film takes the shape of the product, packaging it. Thus, it is possible to pack not only foodstuffs, but also industrial goods. Still, at enterprises engaged in the packaging of drinking products, caps are placed on bottles with the help of thermal tunnels.

Methods of heating thermal tunnels.

According to the method of heating, thermal tunnels are divided into two types.

• Electrical.
• Non-electric.

Non-electric tunnel ovens heating is carried out by burning fuel. They can operate on both natural gas and coal and oil products.

Electric heating method used much more frequently. In such tunnels, heating occurs due to tubular electric heaters (heaters), but modern thermal tunnels use the heat of infrared emitters.

Unlike heating elements, where heating occurs due to hot air, they carry out work using infrared radiation which in turn makes this type of heating more economical and efficient.

One of the disadvantages of traditional heating with heating elements is the presence of drafts in the furnace (and they cannot be avoided in tunnels). Due to the constant cooling of the air, the process of heating products takes longer, and therefore more energy is consumed. In addition, unevenly heated air can disrupt the technological process of product packaging, which also negatively affects production.

Infrared heating in the thermal tunnel distributes heat evenly on products and drafts do not affect the quality of the production process.

One of the positive qualities of stoves with infrared emitters is considered the ability to heat an object not only on the surface, but throughout the entire volume. And automatic temperature control protects products from overheating.

The device of thermal tunnels.

In order for the products to be heated equally and evenly, infrared emitters are located on all sides inside the tunnel. The longer the tunnel, the more emitters are installed in it.

To keep the heat generated inside, the tunnels are equipped with reflectors- stainless steel reflectors. This is a special curved metal plate that is located inside the tunnel. The reflectors are mounted on the inner walls of the furnace so that the heat emanating from the emitter is reflected from it and directed to the heated object. This process provides efficient heating with minimal energy consumption.

For the movement of products in thermal tunnels, not only conveyors are used. For example, for processing cables, plastic profiles, polymer pipes, etc., other technical means are used to allow products to move inside the tunnel.

Thus, the use of infrared emitters in thermal tunnels is superior in many quality characteristics to tunnel furnaces with heating elements.

Many dream not only to work well, but also to have a good rest, to enjoy their own health and beauty. And to ensure a good rest, many go to country baths. If there is none, then an infrared sauna can be offered as an alternative.

Although the device itself was developed back in 1965, they were put into mass production only in 1979. And almost immediately there were models not only for salon conditions, but also for individual home. The heart of any infrared sauna is the infrared oven or heater. They are made of ceramics and are completely safe for human health. According to some data, the depth of penetration of this beam into soft tissues is 4 cm.

The infrared oven for a sauna consists of a reflector, as well as a lamp, the power of which is 250-300 watts. It is the lamp that gives out the infrared waves of the desired frequency. As a rule, its indicator fluctuates in the range of 1400-3000 nm. This infrared oven is connected to the control panel, which allows the person inside the cabin to independently regulate the temperature inside the sauna.

Installing an infrared oven is not a tricky business. It can be placed both on a perfectly flat surface and in the corners of the room. IR emitters can also be installed when converting a conventional bath or sauna into an infrared one. First you need to determine the place where the person will be placed during the adoption of the procedures. It is necessary to create a single field of infrared emitters, in which there will be no empty spaces. In this case, it will be possible to provide better warming up of the body, which means that the effect of adopting such procedures will be the best.

Usually the infrared sauna is small, 130*100cm. Based on this, the recommended number of ovens for installation is six pieces. Four lamps are installed on the back wall of the sauna (they will heat the back of the back), two emitters are located in the front corners. In order for the calf muscles to warm up simultaneously with the body, you need to install another emitter, directly at the level of these muscles. The lowest emitter is placed in a horizontal state, while radiators on walls can be installed vertically. Well, so that condensate does not accumulate in the infrared sauna and air is removed, it is necessary to install special boxes.

Differences between a regular bath and an infrared bath

To install exactly the bath that will benefit in the future, you need to know their differences. For example, when in doubt between choosing a traditional or infrared bath, you need to remember the following:

• The traditional bath involves heating the air with hot stones, which are preheated to a temperature of 220 ° C. To prepare such a bath, it will take at least 1-1.5 hours. From the moment you turn it on to the moment you take the procedure in the infrared sauna, no more than a quarter of an hour will pass.
• The infrared heater acts with its heat directly on objects, in particular, human soft tissues. As for the air temperature and its humidity index, they practically do not change, which is more comfortable compared to a conventional bath. Well, since the heat of IR heaters is not wasted, they are more economical.
• For the construction of a bath (Russian, Finnish, Turkish), sometimes quite a lot of time is needed, as well as materials. In addition, it is necessary to invite specialists to perform such work, to purchase the necessary materials. For an ordinary bath, fire safety is an important issue. It requires ventilation. If you turn to the infrared sauna, then the maximum installation time is half an hour. Well, in the case of mobile options, the assembly time is generally 3-5 minutes. The device of an infrared sauna does not require active influence on the surface (drilling, using nails).

Disadvantages of an infrared oven

The infrared sauna oven has some disadvantages, which are better to be familiar with before purchasing this device:

• – the small size of the infrared sauna does not allow organizing such friendly gatherings, as, for example, in a regular bath or sauna;
• – a visit to the infrared sauna has a number of contraindications, for example, certain diseases of the internal organs. And they need to be familiarized with before accepting the procedures;
• – if there are specific diseases, then before taking procedures in the infrared sauna, you need to get a recommendation from your doctor.

The cost of an infrared oven ranges from 1300 to 3200 US dollars. In some cases, the cost includes the installation of a booth. Moreover, this type of sauna can be installed directly in the apartment and for this you do not need to spend time and nerves on a package of permits. The infrared cabin can be installed in any part of the house where a shower is nearby. Sauna preparation time for procedures is only 15-20 minutes, while a similar procedure in a classic bath will take at least two hours. If the cost of an infrared sauna is not affordable, then you can even assemble it yourself. This can be done in several ways. For example, all of the components can be purchased directly from the manufacturer and assembled by yourself. Installation time will take no more than two hours.

Another method involves the use of prefabricated panels, which are assembled by analogy with standard blanks. Well, you can generally get by with a frame structure, which is assembled on your own. To do this, you will need a wooden beam, lining, heat-insulating material, as well as infrared equipment. To save space, such a sauna can be placed in a corner, and the power regulator can be installed directly under the bench seat. During the assembly of the infrared sauna, it is necessary to think over the lighting and ventilation system.

To correctly understand what exactly we are talking about, you should remember the basics of what IR rays are.

Let's understand the terminology

Infrared is a type of electromagnetic radiation, described by optical laws. That is, the nature of IR radiation is similar to ordinary light. These rays in the spectrum occupy the range between visible (red), with L=0.74 μm (where L is the wavelength), on the one hand, and HF radio emission, L=(1-2) mm, on the other.

This region of the spectrum is divided into three groups:

• DV - Long-wavelength (50.0≤L≤2000) µm;
• MW - Medium wave (2.5≤L≤50) µm;
• SW - shortwave (0.74≤L≤2.5) µm.

This radiation takes place in any heated body. Moreover, the higher the source temperature, the shorter L, and the more intense the IR radiation.

At low temperatures, almost the entire range of such radiation is in the infrared range. Visually, such a body looks dark. As the temperature rises, the wavelength emitted by the body shifts towards the visible spectrum, passing, sequentially, red, yellow and, when high temperature values ​​are reached, white.

On the one hand, this information is not related to the topic of this article, but on the other hand, it is directly related. It allows you to understand the terminological confusion that IR oven manufacturers allow themselves when describing their products:

• Some call it infrared;
• Others - longwave;
• Third - dark;
• Fourth - light.

But all of the listed ovens are infrared. And the discrepancy in the names is due to the fact that DWs have a lower temperature of the outer surface, so their IR radiation lies in the long-wave range. Such emitters are often referred to as dark ones, because. at such temperatures, the bodies practically do not glow. CB ovens are called gray. Their outside temperature is higher. And KV are characterized by max temperatures, and are called light, or white. In numbers it looks like this:

• Superdark bodies — (200≤t≤400)°С;
• Dark - (400≤t≤600)°С;
• Catalytic low temperature
• (600≤t≤800)°С;
• Medium temperature light - (800≤t≤1000)°С;
• High-temperature light - over 1000 ° C.

The design of the infrared oven

IR stoves for saunas are more correctly called heaters, since the principle of their operation is similar to heaters.

These devices have:

• metal or ceramic heat-resistant case of a rectangular shape, having the appropriate strength;
• an IR lamp is installed in it, similar to a fluorescent lamp (daylight);
• the case contains a heat-reflecting screen and a heat-insulating layer that protects the case from overheating;
• reflector that radiates heat;
• panel on which the heating elements are mounted.

When connected to the mains, the latter are heated. Heat is transferred to the reflector - emitter. The room warms up in stages. At first. Radiation zone. Then the air in the room. This ensures even heating.

In modern products, the following elements can be used as a heater:

• ceramic. A plate of ceramic material in which a high-resistance conductor is embedded:
• (nichrome), designed for heating up to a thousand degrees;
• Fechral (with very high resistance) - up to 800 ° C, respectively.

Due to specific design features, they are used only in ceiling and wall models. They are not used in floor-standing devices. Average service life - up to 4 years;

• Quartz. They are made from tubes made of quartz glass. They have insulation made of Al profile silt, which allows to achieve heat radiation from the entire surface of the plate at once. In many models there are several similar heaters.

Products are designed for seven years of operation;

• Carbon. A tube made of quartz, in which a carbon thread is embedded in the form of a spiral. The flask is vacuum. Carbon threads are heated up to 3000°C (while maintaining strength). The type of heating element determines the heating temperature of the reflector plate. Usually it is (200-600)°C. But max case heating temperature ≤ 60°C.
• Film emitters. They are fixed on the entire inner surface of the cabin (walls, ceiling). operating temperatures of the surface of such a radiator (25-50)°C. Often used in conjunction with ceramic.

The average dimensions of such a device: (1000-1500) * 160 * 40. Weight, depending on the model, (3.5 - 5.0) kg.

IR heaters are offered to the client in the following configuration:

• Complete heater;
• Fasteners included (this includes brackets, as well as hardware).

Everything else needs to be purchased separately:

• Automatic switches;
• Cable and plug matched to the existing load;
• thermostat;
• Other accessories.

Installation of IR ovens

Such heaters can be installed:

• On the floor. The downside is that they take up a lot of space. There is a high probability of overturning by negligence. Therefore, the devices must be equipped with an automatic shutdown if the heater falls;
• On the walls. Attaching is more difficult. But this is fully offset by the safety of this option, its compactness and visual appeal;
• On the ceiling. Requires the most complex installation and adjustment.

There are options for IR ovens designed for corner installation. They radiate in the (90-120)° sector.

To maintain the required temperature, special thermostats are used.

The zone of maximum efficiency of the heaters is approximately 150 mm from the body of the bather. With this in mind, the vertical wall-mounted installation option, in the immediate vicinity of the shelves, is considered optimal.

To warm up the legs at the level of the calf muscles, one or two heaters are installed.

Infrared chest heaters are mounted in the corners of the sauna cabin.

The optimal power for an infrared sauna is 350W (when located at a distance of 150 mm from the body). Higher capacity heaters are not recommended. At this distance, they can cause a burn. And at a greater distance, the efficiency of IR radiation decreases.

The surface of the installed emitters needs to be cooled. This explains the recommendation to leave between their rear wall and the enclosing structure of the sauna cabin 30-50 mm for the formation of convective flows. This allows you to cool the devices and reduces the warm-up time of the entire volume of air in the sauna cabin.

Furnaces are connected to a standard power supply network (230V/50Hz) at a current strength of 15A. a special socket for connecting the infrared sauna cabin is not required.

IR oven control

There are 2 control options:

• Provides temperature control. The heaters are turned on and off automatically by commands generated by the VCT (temperature control) sensor. This option does not allow you to completely warm up the body of a person in the steam room;
• Designed to control power consumption. These models are designed to change the intensity of IR radiation, which allows you to select the indicator that is optimal for a particular person. In such a case, the entire human body is heated evenly, gradually and smoothly. What provides the maximum therapeutic effect.

To control IR ovens can be used:

• External control panel located outside the sauna cabin. Allows you to set the radiation power and duration of the procedure. After the set time has elapsed, the system disconnects from the network automatically;
• The built-in block of automatic equipment for regulation of work of all heating elements. With an average power consumption of 1.1 kW, this product is designed to control 6 IR heaters. Therefore, they are equipped with mini steam rooms, for one or two users. For larger saunas, a more powerful (1.5 kW) unit with 8 heaters is recommended;
• Internal remote control for adjusting the microclimate parameters to optimal values.

Advantages of IR ovens

Among the main advantages of such heaters for saunas, it should be noted:

• Their compactness, which makes it possible to complete them with even small apartment saunas;
• Simplicity and convenience of installation and dismantling;
• Autonomy. Such furnaces do not require constant human control and do not need periodic addition of fuel;
• Minimum warm-up time. The classic oven will heat the steam room to the desired temperature in 1.5 - 2 hours. IR oven requires ≤ 20 minutes. At the same time, oxygen is not burned out of the air;
• The low temperature of the case allows you to mount such heaters on surfaces finished with any materials;
• High economy. The choice in favor of IR ovens gives double savings:
• They are cheaper than classic electric furnaces;
• Consume 80% less electricity.

The choice of infrared saunas allows those who like to visit steam rooms to equip them even in their own apartment.

In these polymerization ovens, infrared radiation energy is used to heat products and paint. They usually use either electricity or gas as their energy source. Such heating devices are efficient: powder paint coatings can be formed in them in just 30 seconds. However, sometimes IR ovens, both electric and gas, are limited in use. Due to direct radiation, they are unsuitable for heat treatment of products of different thicknesses and parts of complex shape. Coatings on such products can only be obtained in a convective or combined IR convective oven.

As shown in the figure, it is possible to heat the polymer coating to curing temperature in an IR oven several times faster than in a convective one. High speeds of IR heating make it possible to form coatings without resorting to complete heating of the entire mass of the product. You can quickly heat the surface and just as quickly cool it. Thus, the overall processing time is significantly reduced.

Often there is "free heat" in an IR oven, which is generated by convective transfer from heated products. It can contribute to the heating of inaccessible parts of the product, providing a more uniform formation of coatings.

By the design of the furnace, IR heating differs from convective-type heating devices. They can be continuous and intermittent and differ in the type of emitters used - long-wave, medium-wave and short-wave radiation.

Typical dependences of curing of coatings obtained from powder paints with different heating methods.

Shortwave emitters
provide the highest heating rates (temperature 1600-2000 °C). Incandescent tungsten lamps (shortwave) convert over 80% of electrical energy into radiation and reach operating temperatures in a fraction of a second.

Medium wave emitters provide temperature from 800 to 1250 °C. The most common emitter of this type is the quartz tube heater, which typically uses chromium-nickel wire as the filament. Medium-wave emitters convert from 60 to 80% of the energy into infrared radiation, the rest is converted into convective heat.

Longwave emitters usually they are a metal radiating tube operating in the temperature range from 400 to 600 ° C. Long-wave emitters convert from 50 to 70% of the energy into infrared radiation.

The most important factor in choosing the right IR emitter is the total thermal power applied to the surface of the product. Many types of radiators can be adjusted to a wide range of heat outputs by changing their operating temperatures.

The IR heating method has a number of advantages:

flexibility in plant management;

high heating rate and increased energy efficiency;

· compactness of placement of installations;

low impact on the environment.

One of the main reasons for the success of IR installations is their ease of use. In a convection oven, it is impossible to quickly change the heating rate of the workpiece. At the same time, medium-wavelength IR emitters can turn on and off with an interval of approximately 1 min, and short-wave emitters - from 1 to 5 s. On/off controllers of various powers can also be used to provide a wide range of control by adjusting the power of the emitters. (It should be noted that on/off controllers cannot work with shortwave emitters. Due to their fast response, they require a touch-controlled robot.)

Optical pyrometers can also be used to estimate the product temperature and automatically adjust it.

IR ovens can be custom built with different radiating elements (panels). Panels are installed vertically or horizontally.

Application efficiency. IR ovens allow you to heat parts much faster compared to convection ovens. By changing the specific power, it is possible to significantly adjust the heating cycle in the direction of decreasing or increasing.

In the case of coloring plastic parts as a result of the high speed of IR heating, the risk of deformation of their surface can be reduced.

Scheme of automatic temperature control in IR heating installations:

1 - temperature sensor; 2 - emitters; 3 - control apparatus with touch control; 4 - monitoring and control devices; 5 - product; 6 - conveyor.

Due to the high efficiency of IR heating, the cost of IR curing of coatings can be comparable and even lower than when using gas (convection oven).

Heating time of different substrates up to surface temperature 150

* Specific power of electric IR oven 20 kW/m2.

Accommodation. Typically, IR heating devices require much less floor space to install compared to convection ovens. Companies with a convection oven and wishing to increase the output of painted products by increasing the speed of the conveyor, can install a compact IR oven (typically 1 to 3 m long) in front of the existing convection oven.

Comparative characteristics of IR and convective heating ovens

It should be noted that the use of electric IR units can help the coating manufacturer meet stringent environmental requirements. There are no by-products of combustion that must be removed and neutralized.

Often, for curing polymer coatings obtained from powder paints, heating devices of a combined type are used - IR and convective heating furnaces are installed in series. The IR oven functions as a "quiet zone" where the powder is melted without being blown away from the part. The convection oven completes the coating formation process.