Gas infrared emitters for industrial premises: device, principle of operation, varieties

IR devices that generate heat and light fluxes are actively used in various areas of production and private economy.Gas infrared emitters are most in demand for industrial premises. Their action is based on the ability of a heated body to release the resulting heat into space.

You will learn everything about the operating principles of infrared equipment from our proposed article. We will talk about the types of infrared equipment and their characteristic differences. Let us introduce you to the leading models on the market.

The essence of infrared radiation

Infrared radiation differs from ordinary and so familiar visible light. They are similar in the speed with which they spread and cross space. Both varieties are capable of refraction, reflection and bunching.

Unlike ordinary light radiation, which is electromagnetic waves, IR flux has both wave and quantum properties. That is, it transmits both light and heat.

Both ordinary light and infrared radiation are streams of electromagnetic waves. The difference is that in the first case the visible component predominates, in the second the visible component is combined with the thermal

The light supplied by infrared devices moves in waves.Electromagnetic light vibrations are in the spectrum segment from 760 nm (nanometers) to 540 μm (micrometers). The heat generated by IR emitters is a flux of quanta. Their energy ranges from 0.0125 to 1.25 eV (electron volts).

The heat and light fluxes emitted by infrared devices are interconnected. As light intensity increases, the quantum heat flux decreases. Depending on the temperature, infrared radiation may or may not be perceived by our eyes. Thermal radiation is not visually detectable.

This specificity of infrared radiation is used in industry to accelerate polymerization and hardening processes. The thermal part of infrared radiation makes it possible to determine the presence and location of a person or animal in dimly lit and unlit night periods.

Infrared heating devices emit light in combination with thermal energy, used to create a comfortable microclimate on parking lots, workshops, production halls, poultry farms, greenhouses and many other objects

The non-standard operation of IR devices that emit light in combination with heat became the basis for the development of night vision devices. It is used in flaw detection, in hidden alarm systems and in technical devices for photography in the dark.

Both components infrared radiation almost do not dissipate in the space being processed; they seem to focus on objects located in the zone of their influence. Heat penetrates into the body of the heated object, the depth of penetration depends on the properties, structure and material of the object. The depth varies from a tenth of a mm to several mm.

Infrared heaters are installed on the floor, attached to walls, or suspended from the ceiling. The devices are distinguished by flameless combustion, preservation of oxygen in the surrounding space, and do not raise columns of dust, unlike convectors

When used for industrial purposes, the wavelength from infrared emitters is selected based on the technical characteristics of the object or substance. IR rays pass freely through the air mass, so heating is carried out without noticeable losses. This circumstance is reasonably considered a significant advantage in production.

In addition to heating and illuminating the area treated by the device, infrared emitters are used to solve the following problems:

Types of infrared radiation sources

The simplest sources of IR radiation include those that are very familiar to us all incandescent lamps, operating under low voltage. Under such conditions, they mainly emit infrared streams.The share of light electromagnetic waves is insignificant, but it is still determined optically.

Nowadays, private consumers, construction and production organizations have many different types of IR emitters at their disposal.

The scope of their application is determined by:

• operating temperature;
• maximum wavelength value;
• zone in which the infrared flux is distributed evenly.

Taking into account the listed characteristics, a radiating device is selected that is designed to solve specific problems.

The most common types of IR emitters include:

• Lamps with mirror reflecting devices. At maximum radiation, their wavelength is 1.05 microns.
• Quartz tube lamps. Their wavelength at maximum radiation is in the range from 2 to 3 microns.
• Rod non-metallic heaters. Structurally, they are supplemented with reflectors, the maximum wavelength is from 6 to 8 microns.
• Tubular electric heaters. Widely used in everyday life, used in production are devices with heating elements.
• Infrared burners. They are equipped with ceramic or metal perforated nozzles. They are used in construction for heating open and closed areas during the construction of a building and finishing work.

Sources of infrared rays have found application in farming. With their help, young birds and newly born pets are heated. Emitters are installed in greenhouses to stimulate the growth of cultivated varieties, in barns and granaries for drying.

Sources of infrared fluxes are divided into:

• Infrared lamps. These are “light” emitters and devices that supply thermal radiation.
• Heaters. Devices used for heating confined spaces and open spaces. These include models that run on electricity, liquid or gaseous fuel. The heating element can be either a heating element or a spiral made of a high-resistance alloy.

According to the classification by wavelength, infrared sources are divided into two main groups: dark and light. The former work by releasing long waves into space, the latter - short ones.

Dark and light IR emitters

By definition, “bright” sources are capable of emitting light. The streams they emit are perceived by vision, although it is still difficult to call them bright lighting and should not be used for this purpose at all.

“Dark” devices deliver a flow of heat invisible to humans, felt by the user’s skin, but not visually detected. The boundary value between “light” and “dark” is considered to be a wavelength of 3 microns. The limiting temperature of the heated surface is 700º.

The property of infrared emitters to supply thermal energy is actively used in greenhouses, chicken coops and farms to support young animals

The most famous representative of the “dark” heating unit is Russian brick stove, which has been successfully heating low-rise buildings for many centuries. Among the “light” ones, as we already understand, is an incandescent electric light bulb, if it supplies no more than 12% of light. Its main energy is directed towards generating heat.

Features of the design of light fixtures

Structurally, light sources are similar to a typical incandescent lamp. However, there are differences in the filament bodies. For bright infrared devices, the temperature cannot exceed a limit of 2270-2770 K. This is necessary to increase heat flow by reducing light emission.

Just like standard light bulbs, the filament body, made of tungsten filament, is placed in a glass bulb. Only the flask is equipped with reflectors, thanks to which all radiant energy is focused on the heated object. In this case, a small part of the energy is spent on heating the bulb base.

The bulb of light infrared sources heats up to high temperatures, so it also participates in the process of heat transfer into space. The thermal energy from the heated flask is not focused by the reflector and goes out into the untreated space; it is the component that reduces the efficiency of the device.

In design and connection method, infrared lamps are very similar to conventional incandescent light bulbs. However, their operating temperature of the filament body is significantly lower, due to which the service life is increased many times over.

The productivity of a light infrared source on average does not exceed 65%.It is increased by placing a tungsten heating body in a tube or similar flask made of quartz glass. This solution makes it possible to increase the wavelength to 3.3 microns and reduce the temperature to 600º.

This option is used in quartz IR heaters, in which chromium-nickel wire is wound around a quartz rod and the whole thing is placed together in a quartz tube.

Light infrared emitters have low performance. The efficiency of their infrared flux usually does not exceed 65%

The essence of the work is the double use of filament wire. The released thermal energy is partially used for direct heating, and partially for increasing the temperature of the quartz rod. A red-hot rod also emits heat.

The advantages of tubular devices include, quite reasonably, the resistance of all components made of quartz and ceramics to atmospheric negativity. The downside is the fragility of ceramic parts.

Specifics of operation and design of dark heaters

The so-called “dark” sources of IR fluxes are much more practical than their “light” counterparts. Their radiating element differs in structure for the better. The heated conductor itself does not emit thermal energy; it is supplied by the surrounding metal shell.

As a result, the operating temperature of the device does not exceed 400 - 600º. To ensure that thermal energy is not wasted, dark emitters are equipped with reflectors that redirect the flow in the desired direction.

Long-wave emitters of the dark group are not afraid of shocks and similar mechanical influences, because the fragile polymer or ceramic element in them is protected by a metal casing and a protective heat-insulating layer. The efficiency of emitters of this group reaches 90%.

But they are not without their drawbacks. Dark group heaters depend on the design features of the device. If the distance between the main radiating element and the surface of the device is large, then it will be washed and cooled by the air flowing past. As a result, efficiency decreases.

Due to their design features, dark models are installed for heating rooms with low ceilings and areas that require linear heat supply. Light - placed where processing of rooms with high ceilings and vertically elongated areas is required.

Gas burners as a source of IR rays

Devices in which flameless gas processing occurs are called gas burners or gas infrared emitters. The thermal energy released with high intensity is transferred into space through the radiating surface of the unit.

It is gas infrared burner-type heaters that are used on an industrial scale during construction and installation work.The predominant volume of thermal energy is transmitted by radiating ceramic burner nozzles.

The following are used as nozzles:

• ceramic plates with perforations, which can be flat or embossed;
• ceramic plates with evenly distributed pores;
• ceramic elements with a nichrome mesh screen, metal mesh and all kinds of catalytic attachments.

All of the listed types of holes in a ceramic or metal element are fire channels.

The heat generation of the catalytic nozzle is based on the oxidation process activated when gas is supplied to the plate

The fuel for operating this type of infrared emitter is main gas, as well as its liquefied version or artificially created gases. In Russia, they produce burners designed for processing liquefied and main gas. Foreign equipment is designed mainly for processing liquefied and artificial versions.

Infrared gas burners process gas with an air mass combustion coefficient that is actually equal to unity. They operate on mains, liquefied and artificial gas.

If the operating rules are not violated, then combustion products from the operation of a gas burner are released in minimal quantities with an insignificant content of nitrogen oxides and carbon monoxide.

To supply gas, gas infrared burners (GIG) are equipped with nozzles through which gas is pumped at high speed. This gas supply ensures the injection of air required for combustion. It is “pushed” by a high-speed flow through the injector into the distribution chamber.

A metal structure is placed above the emitting nozzle of the device. It increases efficiency and serves as a support for dishes if you cook on the burners

The gas not only injects air, but also mixes with it in the injector, resulting in a gas-air mixture suitable for complete combustion. This mixture moves to the surface of the ceramic nozzle through its pores, perforated holes or slits, where it burns completely in a thin layer no more than 1.5 mm thick.

Burners with flat ceramic nozzles

The predominant amount of thermal energy is transferred to ceramic tiles, which are heated to ultra-high temperatures in less than a minute. The outer surface of the ceramic element turns into an additional source of heat flow.

The ceramic nozzle accounts for 40 to 60% of the radiation transmitted by an industrial gas IR heater. In order to increase the efficiency of the device, a mesh screen is installed above the nozzle.To increase the heat transfer surface, perforated tiles are glued together using fire-resistant putty.

An important indicator is the diameter of the fire channels. It determines what gas the device can process. The total number of holes in the ceramic tile depends on the diameter. The more there are, the more fragile the heat-emitting element will be and the GIG will be sensitive to mechanical damage.

Heaters with fin type nozzles

In addition to flat ceramic nozzles with perforations, relief elements are used. The use of a ribbed surface in this case stimulates the flow of heat exchange between the radiating surface and the burning gas. Ribbed ceramic tiles heat up better, while the thermal load on the radiating element does not increase.

Flat and ribbed ceramic nozzles heat up to 1473 K. But porous ceramic elements only heat up to 1237 K. The porous version is easier to manufacture and therefore cheaper.In addition, waste from the ceramic industry is used in its production.

The use of ceramic nozzles with a relief heat-emitting element allows you to significantly increase the area that transfers heat to the consumer

The thickness of the porous tiles reaches 30 mm, which significantly increases the resistance of the nozzle to mechanical stress. During operation of a burner with such a nozzle, the gas-air mixture emerging from the distribution chamber burns on the outer surface of the ceramic tile in a layer of up to 2 mm.

The combustion area in the porous nozzle moves from the outer surface to a depth of 3-5 mm. In this case, the heating temperature reaches only 1123 K.

The disadvantage of porous nozzles for hygroscopic injection is the excessively high hydraulic resistance, which makes it impossible to use low-pressure main gas.

Equipment with metal mesh

However, all of the listed types of attachments are made of ceramic, which means that, despite the thickness and all sorts of tricks of the manufacturer who wants to increase strength, they are still fragile. Fragility is especially annoying if the device needs to be constantly moved.

Therefore, to heat sites during construction or installation work, a more durable type of burner, equipped with a metal double mesh, was developed. In such a device, the gas-air mixture is processed in the space between the nozzle and the grids. The surface of the outer mesh heats up to only 1023 K.

The use of a metal mesh made it possible to significantly increase the thermal power of the IR emitter, as well as protect the ceramic nozzle from damage

In GIG with mesh nozzles, these elements are made of heat-resistant alloys with chromium and nickel.The nozzles are made so that the size of the cells of the upper mesh allows the flame to pass freely, and the size of the lower mesh is minimal, critical for the fire to break through. Here, both grids or one can be IR heat emitters.

If the infrared burner processes main gas or a liquefied propane-butane mixture from gas cylinder, only the upper mesh is involved in the spread of thermal energy. If low-load gas is being processed, both grids radiate heat. In this way, heat transfer is increased.

However, the maximum efficiency value of GIG with meshes does not exceed 60%, because the hydraulic resistance of the nozzles is twice as high as that of perforated ceramic tiles of all types. True, it is less than that of porous nozzles.

Devices with increased thermal power

The rather low efficiency of infrared gas emitters with ceramic plates and grids forced us to look for ways to increase thermal power. The result was achieved by introducing a new type of nozzle, which is a ceramic panel with a number of slots.

In the cut, the cracks have a sudden widening, their entrance holes are smaller than the exit holes. This solution increases the efficiency of the burner due to the recirculation of combustion products, i.e. their return to the base of the flame within the fire channel. In addition, the flame in such models is more stable and is much less likely to die out in the open wind.

To increase the thermal power, various techniques are used, one of which is the displacement of the slot holes relative to each other. This solution also helps protect against wind damage.

The live cross-section of slotted panels averages 55–60% of their actual total cross-section. Burners equipped with them operate on medium pressure gas. The outer plane of the nozzle is heated to 1723 K.

Emitters with resistance to wind loads

Stability of operation under wind load is an important indicator for choosing a gas infrared burner used in construction or assembly of production plants. Not all industrial infrared emitters that process gas have this quality.

For open areas, special devices are needed that:

• characterized by stable injection, depending on gusts of wind;
• equipped with a device that prevents deflection of the jet emerging from the nozzle;
• protected from active cooling of the surface radiation occurring due to the influence of winds.

The technical data sheet of gas equipment capable of heating in gusty winds and not going out indicates wind resistance. This characteristic for commercially produced infrared burners is approximately the same as for direct burners, i.e. frontal wind exposure, as well as side blowing.

A reduction in the injection ratio causes a flame to appear on the outer surface of the radiating panel. At the same time, the temperature drops sharply. It is reduced by cold air penetrating into the combustion area.

Wind resistance is physically related to the specific thermal load and the volume of air entering the nozzle during the combustion period. With excess and high air flow speed, the efficiency of the infrared emitter is reduced. The reduction is accompanied by the appearance of flames, darkening of the radiating surface and the cessation of operation of the unit in flameless mode.

Review of IR heater manufacturers

Gas appliances for creating a favorable microclimate at a construction site, workshop, production workshop and similar facilities are produced by both domestic companies and foreign companies.

According to consumers, the rating of Russian-made products is topped by gas burners of the Solarogaz brand. The assortment presented by this company includes models designed for heating areas of various sizes. The units can be used in greenhouses, garages and open areas.

One of the most popular types of gas infrared equipment on the domestic market and proven in practice is the line of gas burners and stoves from the company Solarogaz

The only negative that buyers and actual owners of gas burner and stove models from the capital’s manufacturer should take into account is the lack of security system sensors. Therefore, they can be used in everyday life, but with precautions.

Products from the Pathfinder company are not inferior in popularity. However, the product line offered to the buyer is dominated by products for household use and tourist options.

Tiles are justifiably popular, used both for heating and for preparing simple dishes, and mini burners from a spray can.

Gas heaters with the Aeroheat logo received excellent characteristics from consumers. This equipment is attractive due to its reliability, based on the use of high-quality components, and its affordable price. Gas-powered stoves and burners from Dixon and Sibiryachka have proven themselves well.

The list of worthy gas heaters from foreign suppliers is headed by gas burners and stoves from the South Korean company Kovea. The brand's products are actively used in small workshops, at painting and construction sites, on hiking trips and fishing.

Gas stoves and burners from Hyundai are not inferior in quality and technical characteristics to devices from European manufacturers. In some indicators they even surpass

To equip workshops, gas heaters from the Italian company Sistema are often used. Models from South Koreans Hyundai and Italian gas stoves Bartolini, which can be used both at home and in the office, are in high demand. Swedish Timberk stoves and Chinese Ballu equipment are distinguished by their reliability and stable operation.

Conclusions and useful video on the topic

The author of the following video will tell you in detail about the operating principle and advantages of IR gas burners:

Details of the organization of infrared heating are presented in the following video:

The installation steps for a ceiling-type gas heater are demonstrated here:

In the Russian Federation, different types of infrared burners are produced, including wind-resistant models. The range offered by the company allows you to choose a device for heating open and closed areas.

Before purchasing, it is important to decide for what purpose and under what conditions the equipment will be used, and then choose either a more productive or durable model that is not afraid of repeated movements.