RU2792382C1 - Electric furnace - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: design of an electric heating device intended for heating and steam generation used for equipping baths and saunas. The electric furnace consists of a body with a lid, inside of which there are electric heating coils in a convector heater with heat-insulating walls and a heater module with heat-accumulating elements, a convection channel, the convection channel body is fixed on the back wall of the furnace body, the convection heater inside the body is located under a closed heater, with an internal electrically insulating material is fixed on the sides of the convector heater walls, the front wall of the convector heater has convection holes, the rear part of the convector heater enters the hole in the rear panel of the convection channel box, on the lid of the furnace body there is a bowl of the outer heater and a convection grill, against which the hole of the convection channel box rests, the hole at the bottom of the bowl of the outdoor heater, it has a branch pipe from the inside, the body of the closed heater with a lid is protected by heat-insulating material, inside the closed heater there is a structure made of shaped pipes with row of holes, insulated heating elements, temperature sensor, in the lid of the closed heater there is a number of slots with a nozzle above them, turned towards the convection channel box, the upper edge of the rear panel of the convection channel box is made flush with the lid of the closed heater.

EFFECT: creation of a structure that provides a stable high-temperature regime for heating heat-storage elements of a closed heater.

11 cl, 7 dwg

Description

The device relates to the field of electrical engineering, in particular to the design of an electric heating device intended for heating and steam generation, and can be used to equip baths and saunas.

BACKGROUND OF THE INVENTION

Known electric heating devices for baths and saunas "Premiera Rusa 220V with a closed heater", Premiere Rusa 380V with a closed heater" (Electric heating devices for baths and saunas, Operation Manual URL: https://vvd.su/pdf/05.03.22- vvd_brosh_pr_rusa_all_compressed.pdf, Electric stoves for baths and saunas /Premera stoves /Premera Rusa stove 220V (with closed heater) URL: https://vvd.su/elektricheskie-pechi-dlya-bani/pechi-premera/premera-rusa-s -zakrytoj-kamenkoj#prettyPhoto,), each of which consists of a block of tubular electric heaters (heaters) and an external fence. At the bottom of the electric heater there is a terminal block for connecting it to the control panel. A chipped stone (gabrodiabase, soapstone or quartzite) is placed inside the electric heating device. The heat storage capacity of electric heating devices is ensured by the presence of open and closed heaters in the devices. To humidify the air in the steam room inside the closed heater there is a “glass” with a heat accumulator. The small volume of the closed heater ensures rapid heating of the heat storage elements, but at the same time, their rapid cooling in the steam generation mode. Additional steam must be obtained from the stones in the open heater. Ensuring the necessary mode of steam formation leads to the fact that the temperature of the steam room itself begins to decrease due to a decrease in the temperature of the heat storage elements during steam formation. The process of steam formation and maintaining the temperature in the steam room is discrete, which leads to a decrease in the quality of the resulting steam, or a decrease in the temperature of the steam room, which, in turn, also affects the quality of steam generation.

Also known is the device "Electric oven for a Russian bath and a method for maintaining the air temperature by an electric oven in a steam room of a bath" (RU2738678, published: 12/15/2020 Bull. No. 35), which includes an insulated furnace body, electric heaters, heat storage elements, a temperature sensor heat storage elements. At the same time, the insulated furnace body is made with a sealed base and side walls fixed on it. Electric heaters are placed in the heat-insulated body of the furnace between the heat storage elements, while each electric heater is made in the form of a heat-conducting flask, in which a tubular electric heater is fixed. Heat storage elements are made in the form of steel rods. An air supply ventilation duct is built into the insulated furnace body, containing a fan with a check valve configured to supply air through the air gaps between the heat storage elements, while the fan with a check valve, the temperature sensor of the heat storage elements and the electric heater are configured to be connected to the control unit. Due to the fan blowing heat storage elements and electric heaters, hot air is supplied to the steam room, while the electric heaters are cooled at this time, and the temperature of the heat storage elements decreases. To obtain steam directly from the heat storage elements, their additional heating is required, therefore, more time is needed to heat the steam room and heat storage elements. The process of vaporization and maintaining the temperature in the steam room is discrete.

Known device "Electric oven for a steam bath room" (RU 2756610, published 04.10.2021 Bull. No. 28) which contains a housing with at least one heating element installed in the inner housing with an outlet. An air shell is formed between the case and the inner case, which is connected by air channels with the blower outlet of the fan and with the cavity of the inner case; the heating element and the fan are connected to a control unit connected to at least one sensor measuring the temperature in the steam room. At least one ventilation hole is made in the inner case, a temperature sensor is installed, connected to the control unit. A temperature sensor is installed between the housing and the inner housing, connected to the control unit. The air channel connected to the blowing outlet of the fan is made with an outlet, behind which there is an adjustment unit made in the form of a damper and connected to the control unit. The steam generator is a container separate from the main device with an outlet for steam, with an inlet pipeline for the constant supply of water evaporated by tubular electric heaters (TEH) located inside the steam generator, the level of which is set by a float valve also in a separate container with a leaky lid connected by a branch pipe to the water supply system. The air temperature in the steam room is controlled by a fan and a damper, and the steam generator used to produce water vapor is used only to maintain the optimal ratio of temperature and humidity in the steam room, preventing the creation of fine steam, which can only be obtained at a temperature of at least 500 ° C The design of the device consists of several components with moving and rubbing surfaces and additional equipment (float valve, damper, fan), which often fail and require repair and maintenance.

It is known the device "Electric oven for sauna with steam generation" (SE500509C2, US5054105A, DE4005793A1), which contains at least one electrical resistor for heating the sauna room and inside which, on top of the resistor, stove stones can be placed, and an evaporator in the form of a steam tank with water, a steam oven, where there is at least one electrical resistor for heating water to a state of steam, and thermostatic controllers, including a sensor located near the outer surface of the steam tank and responsive to temperature rise from the set temperature. A water supply tank can be located next to the evaporator or the water comes directly from the water supply network. The evaporator is additionally connected to a steam outlet pipe and a pipe near the top of the sauna heater. The disadvantages are the complex algorithm of operation of the device, which does not allow to ensure the stability and continuity of the temperature regime and the mode of humidification of the steam room, while the design of the evaporator does not allow obtaining fine steam.

Known device "Electric furnace for baths" RU 2057998, taken as a prototype, containing a furnace with electric heaters and communicating with her chamber with heat storage load. The body of the furnace is formed by a base with a screen and a casing installed above it coaxially, the walls of which form through channels open from below, covered from above with a lid, in the center of which a flexible air-vapor-permeable heat-resistant mesh is fixed, placed in the cavity of the furnace, and louvered windows are located on its sides. In the cavity of the furnace, vertical cups made of heat-conducting material are placed in a W-shape, inside which electric heaters are installed on insulators. The screen prevents heat from spreading to the sides and collects the heat flow to enter the heat storage chamber as a convection flow. The loading chamber of the device is made in the form of a flexible mesh made of heat-resistant material, the sealed cup is made of heat-resistant steel with a wall thickness of at least 3 mm, the cup is partially protected by blinds. In this device, only the body of the glass can be irrigated with water, the temperature of which is 450 ° C,

Infrared radiation is transmitted to the bodies of the glasses, and from them it spreads throughout the volume in the furnace. In the internal cavity of the furnace, a convection air flow occurs, going from below in the channel between the base and screen bodies, which fills the furnace. Infrared radiation partially heats the screen and is reflected from it back to the center of the firebox, simultaneously summing up with other heat fluxes. The temperature of the rising air flow in the center of the furnace reaches its maximum value. The high-temperature air flow focused in the central part, rising, encounters obstacles: the chamber, which it bypasses from the side, and through the channels between the heat-storing load, penetrates into the chamber and evenly heats it (the heat-storage load) to a high temperature. Partially given off heat air, going outside, heats the steam room. The less heated flow in the furnace rises near the wall of the screen, which are also partially heated and give off heat to the channel between the screen and the casing. As a result, thermal self-regulating convection flows appear in the channels, which heat the steam room of the bath. When the temperature in the steam room reaches 125° C, the electric furnace automatically turns off and remains off until the temperature drops to 110° C, and then turns on again, etc. the cycle is repeated. When the heat storage load reaches the required temperature (380°C), water is supplied to it in portions to produce steam. The process of vaporization to obtain dry steam is short-lived. When the required temperature is reached in the premises, the heat storage load may not have time to warm up to the temperature required to obtain dry steam. After supplying water to the heat storage load to produce steam, it will be necessary to restore the temperature required for steam generation, which will lead to an excessive increase in the air temperature in the room. The process of vaporization and maintaining the temperature in the steam room is discrete. Hard infrared radiation indoors can cause burns. The device is proposed for the effective production of dry steam in the steam room 12 m ³ . Going beyond the specified intervals worsens the efficiency of use, as they lead to the production of raw steam or an excessive increase in the power of the heaters while increasing the danger.

DISCLOSURE OF THE INVENTION

The task to be solved by this technical solution is to improve the consumer properties of the device by providing high-temperature heating of the heat-accumulating elements of a closed heater while maintaining the convector at a constant required air temperature in the steam room to obtain the best mode of vaporization.

The result is achieved by the claimed device, which is a frame structure with a metal case in the form of a regular vertically oriented parallelepiped, in the lid of which is mounted a bowl of an outdoor decorative heater with heat-accumulating elements made of natural stones and a convection grate through which hot air enters the room. The bowl of the external heater is made in the form of a container with walls located at an angle to the center of the bowl base, from below, to the hole at the bottom of the bowl, a circular section pipe is welded. Inside the frame structure with a metal casing there is a module of a closed heater with heat storage elements for creating fine steam and a convector heater located under it. A box of a convection channel of rectangular section adjoins the rear wall of the device body, with its upper part going under the convection grate of the device cover. Outside, the device has a composite decorative lining in the form of tinted heat-resistant glass panels or, for example, decorative panels made of stone or brick, which also serves as additional protection against infrared radiation from the device.

As heat storage elements for open and closed heaters, for example, ground or chipped natural stones can be used. In a closed heater, in addition to natural stones, artificial heat-accumulating elements can be used, for example, from metal ingots of various geometric shapes that meet the requirements for resistance to temperature changes, heat capacity and health safety.

The module of the closed heater is a metal body in the form of a regular, vertically oriented, parallelepiped with double walls, a bottom and a lid, between which a high-temperature heat-insulating material is laid, with a thickness of at least 25 mm, for example, ceramic fiber, the physical and chemical characteristics of which make it possible to ensure the lightness, strength and wear resistance of such a structure in conditions of high-temperature operation of the device, to protect the external space from infrared radiation and not to waste heat on heating the steam room itself. The cover of a closed heater fits snugly against the walls of the heater and has a hole through which the branch pipe from the outer heater passes, and to which structures made of profile pipes, for example, are attached from below. square section, with a number of small holes or slots in the lower part of the horizontally arranged pipes of the structure. Structures made of shaped pipes can be additionally supported, for example, on brackets fixed on the inside of the heater walls. At least two heating elements with a total power of at least 3 kW and a thermocouple sensor are installed on the bottom of the heater to control the temperature in the closed heater.

For the release of finely dispersed steam in the lid of the closed heater, a number of small, horizontally elongated, oval slots with a nozzle above them are made, from which, when water enters the heat-accumulating elements of the closed heater, the steam, through the convection channel box, exits through the convection grate of the device into the steam room. The nozzle opening is turned towards the convection channel. Through the branch pipe of the bowl of the outer heater, water enters the structure of the shaped pipes of the closed heater and then, through the holes in the shaped pipes, onto the heat storage elements of the closed heater.

In a closed heater, heat storage elements weighing from 25 to 30 kg can be placed, which can be heated from heating elements located inside the heater up to 500 ° C, without losing heat to heat the room. Due to the tight connection of the cover with the body of the heater, excess pressure is formed inside the heater, which contributes to the reheating of the steam and the generation of fine steam. At a stone temperature of at least 500 ° C, water instantly turns into finely dispersed, so-called “light” steam, which allows a person to breathe freely and easily in the steam room and which does not create clubs of water-saturated steam in the room itself. If you do not maintain a high temperature regime in a closed heater, then, with the formation of saturated steam, part of the water remains in a drip state. Such steam is conditionally called "raw" or "heavy", it leads to a large amount of condensate and enhances the feeling of heat in the steam room. The body in such a steam room becomes wet, without having time to sweat, and breathing becomes intermittent and heavy. The same effect will also occur in case of insufficient heating of the steam room itself at the moment when the heat storage elements of the closed heater are already sufficiently heated to a temperature of at least 500 ° C to create steam.

The convector heater is a structure in the form of a rectangular parallelepiped with two opposite double walls, between which a heat-insulating material is laid, for example, ceramic fiber with a thickness of at least 25 mm, an electrically insulating material is laid on the inside of the walls, for example, a mica plate with a thickness of at least 0.5 mm, the front wall of the convector heater has convection holes in the form of a horizontal grid for air to enter the convector from the steam room to heat it, the opposite back side of the convector heater is open and tightly inserted into the hole in the convection channel box, through which, heated to the required temperature, air enters through the convection grate into the steam room. To protect the opposite wall of the convection channel box from infrared radiation from the inside, a protective screen is installed on it, opposite the convection convector, for example, in the form of an additional metal sheet. Several heating coils are installed inside the convector heater, depending on the required power of the device and the size of the heated room, but not less than 3 kW , which are connected to the electronic control unit through a terminal module fixed outside on the frame structure. The heating elements and a thermocouple temperature sensor located in the closed heater are also connected to the terminal module.

The control unit is a panel on which the information output device, relay temperature control units are located.

The data from the temperature sensor located in the closed heater and from the air sensor in the steam room are sent to the control unit and displayed on the display; if necessary, the air temperature is regulated by means of a relay.

The design of the device makes it possible to provide heating of the steam room without reducing the temperature of vaporization in the closed heater and, conversely, ensuring the required temperature of vaporization in the closed heater does not lead to a decrease in the temperature in the steam room due to the provision of independent high-temperature heating of the heat-accumulating elements of the closed heater while simultaneously maintaining the convector of the device at a constant required air temperature in the steam room to obtain fine steam.

The technical result is the creation of a device design that provides a stable high-temperature mode of heating the heat-accumulating elements of a closed heater while maintaining a constant required air temperature in the steam room by the convector of the device to obtain the best mode of vaporization.

BRIEF DESCRIPTION OF THE DRAWINGS

The essence of the technical solution is illustrated by the following drawings.

Fig.1 - General view of the device without facing panels

Fig.2 - Closed heater module with removed front and side walls without heat storage elements

Fig.3 - Convector heater

Fig.4 - Convection channel box

Fig.5 - Rear view of the device with a convection channel box panel

Fig.6 - Side view of the device with a convection channel

Fig.7 - The structure of the profile pipes of a closed heater

As shown in figure 1, the device is a frame structure with a metal case 1 in the form of a regular, vertically oriented, parallelepiped, fixed on the base 2. On the cover 3 of the device there is a bowl of the outdoor heater 4 and a convection grate 5. Inside the frame structure of the device on a metal panel 6 fixed on the frame structure 1, a closed heater module 7 is installed, and a convector heater 8 is located under the metal panel 6. The walls of the metal case 1 are made in such a way that they do not cover the area where the convector heater 8 is located. structure 1 of the device, a convection channel 9 is fixed, which is closed from above by a convection grate 5 of the cover 3. The bowl of the outdoor heater 4 is made in the form of a container with walls located at an angle to the center of the base of the bowl, to the bottom of which a branch pipe 10 is welded from below. heater 8 the devices are connected to the electronic control unit 11 through the terminal module 12. For example, an air sensor 13 can also be connected to the electronic control unit to control the temperature in the steam room.

As shown in figure 2, the closed heater module 7 is a metal the body, the side walls and bottom of which are assembled from panels 14 with double walls, between which a heat-insulating material 15 is laid. The cover 16 of the closed heater 7 is also insulated from the inside with heat-insulating material 15. a structure of shaped pipes 17 with a number of parallel slots or small holes in the downwardly facing part of the horizontal pipes of the structure. The design of shaped pipes 17 can additionally rely, for example, on brackets 18 fixed on the inner side of the walls of the module of the closed heater 7. For the exit of fine steam in the cover 16 of the closed heater 7, a number of small, horizontally elongated, oval slots with a nozzle 19 above them are made, turned towards the box of the convection channel 9, through which steam enters through the convection grate 5 of the cover 3 of the device into the steam room. At the bottom of the closed heater 7, at least two heating elements 20 are installed in the form of spirals of conductive materials with a total power of at least 3 kW, in metal boxes with stiffeners at the corners and inside the box, filled with an electrically insulating filler, for example, electrical periclase, and a thermocouple temperature sensor 21.

As shown in figure 3, the convector heater 8 is a structure in the form of a rectangular parallelepiped with two side double walls 22, between which is laid heat-insulating material 23, on the inner side of the walls additionally laid electrically insulating material 24, which are attached to the heating elements 25, the front wall The convector heater 8 has convection holes in the form of a horizontal grate 26 for air to enter the convector, the opposite part of the convector heater 8 is open and tightly inserted into the hole on the rear panel of the convection channel 9, slightly going beyond it. The heating elements 25 of the convector heater 8 are connected to the electronic control unit 11 through the terminal module 12, fixed on the outside on the frame structure 1. The heating elements 25 and the thermocouple temperature sensor 21, located in the closed heater 7, are also connected to the terminal module 12.

The design of the convection channel 9 and its location on the device are illustrated in Fig.4, Fig.5, Fig.6. The box of the convection channel 9, shown in Fig.4, consists of a rear panel 27 with small side edges bent at a right angle and a rectangular hole in its lower part for the size of the convector heater 8, which, as shown in Fig. 5, is attached to the frame structure of the device in such a way that the upper edge of the panel 27 of the convection channel 9 is flush with the cover 16 of the closed heater 7, and the panel 28, also with side edges bent at right angles, which is attached to the panel 27, and on top, as shown in Fig.6, comes under the cover 3 of the device.

The convection channel box 9 has a bottom formed by the bent lower edges of the panels 27,28. A heat-insulating material 29 is laid between the box of the convection channel 9 and the metal case of the frame structure 1. A protective screen 30 is installed in the lower inner side of the panel 28, opposite the open part of the convector heater 8.

Figure 7 shows one of the possible design options for uniform distribution of water flowing through the pipe 10 into the structure of shaped pipes 17 to the heat storage elements of the closed heater 7 through a series of parallel slots or small holes in the downward facing part of the horizontal pipes of the structure. The upper part of the structure of profile pipes 17 is made in the form of a small length of a round tube welded to the main structure, which is included in the branch pipe 10.

IMPLEMENTATION OF THE INVENTION

The device works as follows. The device is installed in the steam room and connected to the electronic control unit 11 through the terminal module 12, fixed in the lower side part of the frame structure 1. The control unit 11 allows you to select the automatic operating modes of the device, control and regulate the temperature in the module of the closed heater 7 using a thermocouple sensor 21, in the steam room through the air sensor 13 connected to the control unit 11, to limit the operating time of the device.

The closed heater module 7 and the bowl of the outdoor heater 4 are filled with heat storage material and closed tightly with a lid 16. The tight connection of the lid 16 to the closed heater module 7 can be additionally provided, for example, with a heat-resistant cord laid along the inner perimeter of the lid.

When power is supplied from the control unit by closing the control power contacts of the relay on a spiral of conductive materials of the heating elements 20 of the closed heater 7, they are heated to a temperature of at least 700 ° C, which, in turn, through the electrical insulating material laid in the box of the heating elements 20 , heat the walls of the box. The heat storage material inside the closed heater is heated to a temperature of at least 500°C. The thermocouple temperature sensor 21, located inside the module of the closed heater 7, allows you to control the heating temperature of the heat storage elements.

Independent heating of the room is as follows. When power is supplied from the control unit by closing the control power contacts of the relay on a spiral of conductive materials of the heating elements 25 of the convector heater 8, they are heated to a temperature of at least 250 ° C. The outside air entering through the convection holes of the grill 26 inside the convector heater 8, passing through the heated coils of the heating elements 25, it heats up and, already hot, through the convection channel 9 and the holes of the convection grate 5 enters the steam room. The air heating temperature in the convector heater can reach temperatures up to 200 ° C. As soon as the air temperature in the room is heated to the required temperature in the steam room, which, as a rule, is not more than 110 ° C, the sensor 13 turns off the heating of the convector.

To obtain finely dispersed steam, water is supplied to the bowl of the outer heater 4, water through the hole in the base of the bowl enters the structure of shaped pipes through the steam tube 10 and, through the holes in the lower part of the horizontal pipes of the structure 17, is evenly distributed over the heat storage materials of the closed heater 7 of the device . Due to the tight connection of the cover 16 with the body of the closed heater 7, excess pressure is formed inside the heater, which contributes to the heating of the steam and the generation of fine steam. Water, falling on the heat-accumulating elements of the closed heater 7 heated to a high temperature, surrounded by the heated inner walls of the closed heater, explodes with a characteristic pop. Hot steam with water drops rushes up, but, in a closed space, colliding with the hot surface of the inner walls of a closed heater, it additionally heats up from them and the air between the heat-accumulating elements, while producing repeated “micro-claps”. Due to the high heating temperature of the heat storage elements of the closed heater 7, the water particles become smaller and smaller and so-called light, fine steam is formed.

Finely dispersed steam, being under pressure inside the closed heater 7, flies out at high speed through the nozzle 19 located on the cover 16 of the closed heater 7, and then, through the convection channel 9 and the openings of the convection grate 5 of the device, enters the steam room, creating at the same time , additionally, a special characteristic sound, reminiscent of the “sound of a blizzard”. The nozzle opening is turned towards the convection channel.

The design of the device makes it possible to provide a stable high-temperature mode of heating the heat-accumulating elements of a closed heater while maintaining a constant required air temperature in the steam room by the convector of the device, which, in turn, allows for the best mode of steam generation. The quality of the steam obtained in a closed heater allows a person to breathe freely and easily in the steam room, independent maintenance of the temperature regime for heating the room and creating steam does not allow creating clubs of steam saturated with water in the steam room itself.

Claims (11)

1. An electric oven, containing a housing with a lid, inside which there are electric heating coils in a convector heater with heat-insulating walls and a heater module with heat-accumulating elements, a convection channel, characterized in that the convection channel housing is fixed on the back wall of the furnace housing, the convector heater inside the housing located under the closed heater, electrical insulating material is fixed on the inner side of the walls of the convector heater, the front wall of the convector heater has convection holes, the rear part of the convector heater enters the hole in the rear panel of the convection channel box, on the cover of the stove body there is a bowl of the outer heater and a convection grate, into which the hole of the convection channel box rests, the hole at the bottom of the bowl of the outer heater has a branch pipe from the inside, the body of the closed heater with a cover is protected by heat-insulating material, inside the closed heater there is a const structure made of shaped pipes with a number of holes, insulated heating elements, a temperature sensor, a number of slots are made in the cover of the closed heater, with a nozzle above them turned towards the convection channel box, the upper edge of the rear panel of the convection channel box is made flush with the cover of the closed heater. 2. Electric stove according to claim 1, characterized in that the thickness of the heat-insulating material of the convector heater and the closed heater is at least 25 mm. 3. Electric oven according to claim 1, characterized in that the thickness of the electrically insulating material of the convector heater is at least 0.5 mm. 4. The electric furnace according to claim 1, characterized in that the total power of the heating coils of the convector heater is at least 3 kW. 5. Electric oven according to claim 1, characterized in that an air sensor is connected to the electronic control unit. 6. The electric stove according to claim 1, characterized in that the structure of the shaped pipes of the closed heater rests on brackets fixed on the inside of the walls of the module of the closed heater. 7. Electric stove according to claim 1, characterized in that the total power of the heating elements of the closed heater is at least 3 kW. 8. Electric stove according to claim 1, characterized in that in a closed heater, the heating elements are placed in metal boxes with stiffeners at the corners and inside the box, filled with electrical insulating filler. 9. Electric stove according to claim 1, characterized in that the module of the closed heater and the convector heater are connected to the electronic control unit. 10. Electric oven according to claim 1, characterized in that a protective screen is installed in the convection channel box opposite the convector heater. 11. Electric oven according to claim 1, characterized in that a heat-insulating material is laid between the rear panel of the convection channel box and the body.

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