90results about "Monolithic linings" patented technology

The invention relates to the field of furnace lining materials, in particular to a rapid repairing material for a tapping hole and a furnace lining of an intermediate frequency furnace. The rapid repairing material comprises the following components in parts by weight: 50-70 parts of tabular corundum, 10-20 parts of fused magnesite, 8-15 parts of alumina micro powder, 3-8 parts of nano zirconia, 5-12 parts of silicon carbide, 10-15 parts of silica sol and 2-5 parts of a reinforcing agent. Wherein the reinforcing agent is titanium calcium aluminate coated with chromium nickel boride. The tabular corundum is mainly used as an integral framework; the fused magnesite is matched with the alumina micro powder to form magnesium aluminate spinel with a high melting point; the nano zirconium oxide can fill pores and is excellent in toughness; the silicon carbide has the advantages of high hardness, high thermal conductivity and high melting point; the reinforcing agent is titanium calcium aluminate coated with chromium nickel boride, although the adding amount is small, the high-temperature strength, toughness and thermal shock resistance of the repairing material can be remarkably improved, and especially the long-term corrosion resistance can be remarkably improved.

The invention belongs to the technical field of smelting furnaces, and discloses an energy-saving metallurgical smelting furnace based on intelligent control and a using method thereof, and the smelting furnace comprises a furnace body, a furnace lining, a top cover and a monitoring mechanism; a furnace lining is arranged on the inner side of the furnace body; a top cover is detachably arranged on the furnace body; a plurality of hydraulic rods are fixedly arranged on the top plate; the lower ends of the hydraulic movable rods are fixedly connected with the top cover; a combustor is fixedly arranged on one side of the furnace body; a combustion improver pipe and a combustion agent pipe are arranged on the combustor; two annular pipes are fixedly arranged on the furnace body, and a plurality of connecting pipes are uniformly distributed on the annular pipes; a plurality of burners are arranged on the inner wall of the furnace lining; and a monitoring mechanism is arranged on the furnace body. Key parameters such as temperature and energy consumption in the smelting process are monitored in real time through the intelligent system, energy input and smelting requirements are dynamically matched, and energy waste is avoided; the production efficiency is improved; the product quality is stabilized; the intelligent system can monitor the running state of equipment in real time, reduce the risk of safety accidents and guarantee the safety of personnel and equipment.

The invention discloses prefabricated furnace lining modules, a modular fast-assembly type furnace lining system and a furnace lining installation method.According to the structural form of a furnace lining of a heating furnace, the modular structure of the furnace lining is decomposed into a furnace top module, a furnace wall module and a furnace door module correspondingly, and each prefabricated furnace lining module integrates a refractory layer, a heat insulation layer, an anchoring part and a connecting mechanism; the structural strength and the heat insulation performance are strictly inspected; each module is prefabricated and formed in a factory, during installation, only simple hoisting, positioning, splicing and locking are needed, installation of the furnace lining is rapidly completed like building blocks, the built splicing seams are filled with fireproof sealing materials, and the sealing performance and integrity of the seams are guaranteed. When the prefabricated furnace lining module is used for on-site furnace lining installation, the construction period can be shortened, the construction difficulty can be reduced, the uniformity of the construction quality can be guaranteed, after the furnace lining is damaged, only the damaged module needs to be dismantled and replaced with a new module, maintenance is easy, and the maintenance cost can be greatly reduced.

The utility model provides a single crystal furnace main furnace chamber and a single crystal furnace provided with the main furnace chamber, the single crystal furnace main furnace chamber comprises a cylindrical furnace body, the cylindrical furnace body comprises an outer wall and an inner wall, a vacuum cavity is arranged between the outer wall and the inner wall, and a first thermal insulation layer is arranged in the vacuum cavity. The single crystal furnace has the beneficial effects that the vacuum cavity and the heat preservation layer are arranged, so that heat preservation and heat insulation of the main furnace chamber are realized, the heat preservation effect is ensured, the heat loss is reduced, the power consumption of the single crystal furnace is reduced, and the single crystal drawing quality can be improved.

The invention relates to the technical field of iron and steel smelting, in particular to a heat insulation refractory material and a preparation process and a permanent layer structure thereof, and the heat insulation refractory material comprises the following raw materials: high-alumina bauxite, corundum, corundum spinel, high-purity high-activity alumina micro powder, a high-purity alumina nano light material, an expansion additive, a molding plasticity additive and an inorganic complexing agent; the problems that an existing refractory material is poor in heat preservation, low in strength and insufficient in temperature resistance are solved. Meanwhile, a firing-free preparation process of the refractory material is provided, so that the production energy consumption and cost are reduced; the invention further provides a permanent layer structure comprising the refractory material, the effects of heat preservation, safety and light weight are achieved, it can be guaranteed that the safety coefficient is increased, the thermal resistance rate of the refractory material can be reduced, the heat preservation effect is improved, the advantage that the production cost is not greatly increased is achieved, and therefore the production cost of metallurgical enterprises is greatly reduced, and the production rhythm and efficiency are greatly improved.

The present invention relates to a precast ring for use in a furnace, a refractory lining comprising a precast ring and a dry vibration material and a method of forming a refractory lining.

The utility model discloses a large heat preservation module, which belongs to the technical field of heat preservation modules and comprises a high-temperature-resistant fiber blanket and a low-temperature-resistant fiber blanket which are stacked. The device further comprises a fixing assembly, the fixing assembly comprises a round pipe inserted in the high-temperature-resistant fiber blanket and a round rod inserted in the low-temperature-resistant fiber blanket, and the round pipe and the round rod are relatively fixed. The strength of the insulation block is improved, and the durability and stability requirements of large-size insulation blocks are met.

The invention discloses a modular integrated vacuum high-temperature sintering forming device adaptive to a multi-gravity field environment. The modular integrated vacuum high-temperature sintering forming device comprises a metal sealing experiment box body and an axis heating assembly integrated in the metal sealing experiment box body, the axis heating assembly adopts a high-temperature-resistant vacuum sealing pipe end face sealing structure and is combined with a loose fastening mechanism, so that quick plugging and electrical / mechanical dual locking of a sample unit are realized, and the problems of connection failure and floating under a dynamic load are solved; the heating unit adopts a tubular silicon nitride heat transfer matrix matched with an external zirconium oxide and aerogel multi-layer heat insulation structure, high-temperature sintering in a wide temperature zone of 1100 DEG C to 1600 DEG C is realized under low power consumption, and the temperature rise of the surface of the box body is effectively controlled; the rotary acceleration assembly is connected through the mechanical interface, a variable gravity experiment environment is constructed by using centrifugal force, and the device is small in overall size and high in shock resistance and meets the harsh requirements of space station operation and ground supergravity simulation.

The utility model relates to the technical field of steel rolling heating furnaces, in particular to a water beam stand column for a heating furnace, which comprises an outer pipe and a core pipe which are mutually sleeved, the outer pipe comprises a head pipe, a neck pipe, a body pipe and a tail pipe which are mutually connected, and the core pipe comprises a bevel head pipe and a core pipe body which are mutually connected. The core tube body is arranged at the axis position of the body tube and fixedly connected with the body tube through a connecting piece. The beveled head pipe extends into the head pipe, and a beveled opening of the beveled head pipe faces the water flow inlet; a tail pipe convex flange is arranged at the bottom of the tail pipe, a tail pipe convex flange cover matched with the tail pipe convex flange is arranged at the bottom of the tail pipe convex flange, and the tail pipe convex flange cover is connected with the tail pipe convex flange through a tail pipe convex flange bolt. The water beam stand column is simple in structure, sediment can be removed by opening the tail pipe convex flange cover arranged at the bottom, and the inner pipe wall can be cleaned conveniently.

The application belongs to the technical field of reaction furnace, and discloses a heat insulation structure and a reaction furnace, the heat insulation structure comprising a shell, a cover and a connecting assembly. The shell is hollow inside and is configured to be filled with heat insulation material; the first end of the connecting assembly is positioned at the upper edge of the opening of the shell and extends along the cover to the lower edge of the opening of the shell, and the second end of the connecting assembly is positioned at the lower edge of the opening of the cover or the shell to press the cover to the opening of the shell; the lower edge of the opening of the shell is provided with a clamping piece for clamping the second end of the cover or the connecting assembly. The heat insulation structure is a split structure, which is convenient to transport and assemble, has high reliability after assembly and ensures heat insulation effect.

The present application provides a kind of electronic component heating and pressurizing treatment furnace fast preparation device, including a containing space in the furnace;At least one heating device, is arranged in the containing space to adjust the temperature in the containing space to a predetermined temperature;At least one pressurizing device, to adjust the pressure in the containing space to a predetermined pressure greater than 1atm;At least one replaceable heat insulation liner, including an outer layer and an inner layer;And a fan, is arranged in the containing space, and is connected to a driving motor via a transmission shaft protruding from the cavity, whereby, contaminated and clean replaceable heat insulation liner can be quickly replaced, and is forced in the furnace using a plurality of radial expansion structures and a plurality of C-shaped rings, so that the preparation work can be quickly completed, the downtime maintenance time is greatly shortened, effectively increases production efficiency and capacity.

The application discloses a construction method for prolonging the service life of a large titanium slag smelting furnace, and belongs to the technical field of smelting production equipment maintenance and repair processes. The method is convenient to operate, can effectively guarantee the repair quality, and can effectively prolong the service life of the electric furnace by 3-5 years. The method comprises the following steps: discharging molten iron, slag and a dead iron layer with a specified thickness before stopping power supply and furnace, reinforcing the furnace body, removing a sealing steel platform on an upper furnace shell and corresponding auxiliary dust removal pipelines, protectively removing the furnace shell, furnace wall lining and furnace bottom lining that need to be replaced, manufacturing a new furnace shell, sequentially assembling and welding the new furnace shell, protectively recovering the furnace bottom lining and the furnace wall lining, finally recovering the sealing steel platform around the upper furnace shell and the auxiliary dust removal pipelines, and performing the normal metallurgical production after furnace baking, preheating and slag hanging, so that the repair work of prolonging the service life of the titanium slag smelting furnace is completed.

The utility model provides a kind of sintering machine ignition furnace roof refractory lining structure.The lining structure is by a first prefabricated block with burner hole and a second prefabricated block without burner hole alternate splicing, first expansion joint is equipped between two adjacent prefabricated blocks, second expansion joint is equipped between the adjacent two prefabricated blocks of same column;Each first prefabricated block and second prefabricated block is respectively equipped with multiple refractory anchoring hanging bricks, and the first prefabricated block and the second prefabricated block are connected with the inner wall of ignition furnace roof by refractory anchoring hanging brick respectively.The utility model uses refractory prefabricated part to assemble ignition furnace roof lining instead of integral pouring lining, thereby reducing the size of ignition furnace roof refractory lining pouring body, construction quality is easy to control, its structural strength and uniformity are good, integrity is promoted, avoids stratification, also avoids that pouring body generates more irregular cracks and gap due to size is larger, also shortens furnace heating time, greatly reduces the maintenance construction period.

The efficient natural gas heating furnace comprises a furnace body, a furnace door, a combustion system, a pipeline system and a refractory material assembly, and the furnace door drives a moving trolley to move on a guide rail through chain wheel and chain transmission and drives the furnace door to move up and down; the hydraulic cylinder drives the connecting rod mechanism to drive the furnace door to be loosened and pressed. The combustion system is arranged at the top of the furnace body, the refractory material assembly comprises castable, and a furnace mouth, the lower portion of a furnace lining side wall, the lower portion of a furnace lining rear wall and a furnace bottom are made of the castable; the castable at the lower part of the side wall of the furnace lining is provided with an inclined surface structure, and the inclination angle alpha is 15-35 degrees. The temperature uniformity of the hearth is improved, sealing between the furnace door and the furnace body is enhanced, and the natural gas combustion heat utilization rate is increased.

The invention discloses a high-thermal-shock low-thermal-conductivity plastic material, a preparation method and a use method thereof, and an application of the plastic material in preparation of a steel rolling heating furnace wall, and relates to the technical field of refractory materials for heating furnaces. The plastic refractory with high thermal shock and low thermal conductivity comprises the following raw materials in percentage by mass: 20-45% of microporous zirconium mullite particles, 25-50% of silicon modified special-grade alumina particles, 5-10% of andalusite / sillimanite composite powder, 1-5% of mullite whiskers, 10-20% of an aluminum dihydrogen phosphate / silica sol composite binder, 2-5% of polystyrene microspheres and 3-5% of nano yttrium oxide stabilized zirconia powder. Through the design of the raw materials and the proportion, the thermal shock stability, the heat insulation performance and the refractoriness of the heating furnace wall plastic refractory are synchronously optimized, and the performance indexes of the prepared plastic refractory after burning are as follows: the plastic refractory is not broken after being subjected to thermal shock (water cooling) for 20 times at the temperature of 1100 DEG C, and the breaking strength is 6.8-9.7 MPa after being subjected to thermal shock for 20 times; the breaking strength at normal temperature is 17.7 to 27.3 MPa; the thermal conductivity at 800 DEG C is less than or equal to 0.7 W / (m.K); the refractory material is especially suitable for preparation of a furnace wall for a steel rolling heating furnace.

The utility model provides a workpiece preheating holding furnace which comprises a cylindrical shell, a vapor chamber is fixedly connected to the inner wall of the shell, a plurality of electric heating pipes are arranged in the vapor chamber in a penetrating mode, a containing frame is arranged in the shell, the containing frame is a tubular part, a containing groove is formed in the circumferential face of the containing frame, and the containing groove is communicated with the vapor chamber. A guardrail is arranged on the lower portion of the containing groove, a rotating shaft is arranged in the middle of the upper end of the shell in a downward penetrating mode, the lower end of the rotating shaft is a hemisphere and is movably matched in a preset groove in the inner bottom wall of the shell, a connecting rod is fixedly connected to the side wall of the rotating shaft, and the other end of the connecting rod is fixedly connected with the inner wall of the containing frame. And the upper part of the rotating shaft is fixedly connected with a rotating handle. According to the invention, the placing rack is rotatably arranged in the shell, and the rotary arrangement only needs to be provided with a smaller opening, so that the taking and placing of workpieces can be realized, and the heat loss is reduced.

The invention discloses an anti-stripping aluminum oxide hollow sphere brick and a preparation process thereof, and aims to provide an anti-stripping aluminum oxide hollow sphere brick with strong anti-stripping performance and improved preparation efficiency and a preparation process of the anti-stripping aluminum oxide hollow sphere brick. The brick comprises a brick body, and the brick body is composed of alumina hollow spheres with three particle sizes of 0.5-1 mm, 1-2 mm and 2-3 mm, 3%-5% of a binding agent and 0.5%-1% of a lubricant. The grading proportion of the aluminum oxide hollow spheres with the particle size is 6: 3: 1, the binding agent adopts aluminum sol, and the lubricating agent can adopt zinc stearate; the surface of the brick body is coated with the anti-stripping layer, and the anti-stripping layer comprises 60% of mullite powder (the particle size is smaller than or equal to 5 microns), 30% of alumina sol, 5% of a dispersing agent (such as polycarboxylate) and 5% of water. The aluminum oxide hollow ball brick has the beneficial effects that the brick body of the aluminum oxide hollow ball brick has anti-stripping performance; the preparation device has integrated high-efficiency preparation process efficiency; the brick body cleaning efficiency of the preparation device is improved; the drying uniformity and the operation smoothness of the preparation device are improved; the automation degree and the operation stability are improved.

The utility model discloses a composite energy-saving furnace lining of a white corundum smelting furnace, which comprises a smelting furnace seat, a smelting furnace mechanism is arranged at the top of the smelting furnace seat in a rolling manner, and a furnace lining component is arranged in an inner cavity of the smelting furnace mechanism; the smelting furnace seat comprises a base. A clay heat preservation ring of a composite energy-saving furnace lining in the furnace lining assembly is tightly coupled with and tightly attached to a hearth, the good heat preservation performance of the clay heat preservation ring is matched, outward heat dissipation is effectively reduced, and energy consumption is reduced. The ceramic fiber ring is connected with the clay heat preservation ring through sintering, the structure is stable, the wedge-shaped grooves in the inner side not only enlarge the area of the inner wall of the furnace, enlarge the heat exchange area and improve the smelting efficiency, but also cooperate with the infrared reflection coating to reflect radiant heat, and energy is further saved. The adjacent composite energy-saving furnace linings are coupled through the convex cylinders and the cylindrical grooves, so that disassembly, assembly and maintenance are convenient. The smelting furnace seat is matched with the motor to roll the hearth, so that materials are uniformly heated, and the smelting quality is improved.

The utility model discloses a medium frequency furnace furnace lining structure relates to medium frequency furnace technical field. This medium frequency furnace furnace lining structure, medium frequency furnace furnace lining structure, including at least two groups of firebrick furnace lining, refractory layer and reinforcing structure, firebrick furnace lining is by brick block one, brick block three and at least one group's brick block two, and the refractory layer sets up on two groups of firebrick furnace lining, and the refractory layer is by brick block four, brick block six and at least one group's brick block five, and the reinforcing structure sets up between two groups of firebrick furnace lining. This medium frequency furnace furnace lining structure can divide furnace lining structure into multiple parts, and the different thermal stress, mechanical stress and chemical corrosion degree that furnace lining different parts bear are carried out the maintenance and the maintenance of differentiation, avoid the furnace lining upper part condition to be good, only because the lower part serious erosion is whole replacement entire furnace lining, effectively reduced the use cost, and when dismounting, because multiple firebrick furnace linings have the gap, only need to dismount refractory layer and can operate by sawing reinforcing structure.

The utility model discloses a fully-closed tail gas recovery fixed type silicon carbide smelting furnace which comprises an end wall, a side wall and a furnace hearth, an electrode is embedded in the end wall, and the end wall embedded with the electrode is connected with the fixed type side wall and the furnace hearth to form a fully-closed groove-shaped furnace body with an open upper opening; the groove-shaped furnace body is filled with furnace materials, a film pad is laid on the material face of the furnace materials, the film pad is integrally covered with an airtight film cover, a circle of closed annular sealing belt is arranged in the length direction of the top of the side wall and the length direction of the waist portion of the outer side of the end wall, and the four edges of the film cover extend to the annular sealing belt and are tightly connected with the annular sealing belt in an airtight mode. The fixed silicon carbide smelting furnace is totally closed, valuable tail gas containing carbon monoxide and the like is collected, the problem that smelting tail gas emission in the silicon carbide industry does not reach the standard is solved, and the collected tail gas is used for comprehensive utilization of gas power generation, coal chemical industry rear sections and the like.

The utility model discloses a novel modularized hard ceramic fiber plate furnace lining, relates to the technical field of industrial furnaces, and aims to solve the problems that in the prior art, when a full-ceramic fiber furnace lining falls off, a large-area full-fiber module needs to be disassembled, damaged parts are replaced, and the working efficiency is reduced. A movable top cover is arranged at the top of the box-type furnace external steel structure, bolts are arranged in the box-type furnace external steel structure and the movable top cover, ceramic fiber blankets cover the inner surfaces of the box-type furnace external steel structure and the movable top cover, furnace lining modules are arranged on the other faces of the ceramic fiber blankets, the furnace lining modules are hard ceramic fiber blocks, and stainless steel plates are arranged in the furnace lining modules. When a damaged furnace lining module is replaced, only the damaged furnace lining module and one adjacent furnace lining module need to be dismantled together, the damaged furnace lining module and the adjacent furnace lining module can be dismantled and replaced, and the maintenance efficiency is greatly improved.

The invention relates to the technical field of submerged arc furnaces, in particular to a direct-current submerged arc furnace bottom temperature control system which comprises a furnace shell, and an insulating asbestos board, a high-aluminum aggregate layer, a third-level high-aluminum brick layer, a first-level high-aluminum brick layer, a prebaked carbon brick layer and a clay brick layer are sequentially laid at the inner bottom of the furnace shell from bottom to top. A dry-type sealing ramming material layer is arranged on the inner side of the insulating asbestos plate on the side wall of the furnace shell, a cooling assembly is arranged in the third-stage high-alumina brick layer and comprises an air blower and a plurality of air inlet pipes, air outlet pipes and air conveying pipes, the air outlet pipes are arranged in the third-stage high-alumina brick layer, one ends of the air inlet pipes are inserted into the air outlet pipes and extend to the inner bottoms of the air outlet pipes, and the other ends of the air inlet pipes are connected with the air blower. According to the furnace bottom cooling device, cooling of the furnace bottom of the submerged arc furnace is achieved, the situation that the furnace bottom is heated and cooled rapidly, consequently, prebaked carbon bricks at the furnace bottom warp and the furnace bottom brick floating accidents are caused is avoided, the service life of the submerged arc furnace is prolonged, and the service life of the submerged arc furnace is prolonged. And wide application prospects are achieved in the technical field of submerged arc furnaces.

The utility model provides an anti-corrosion furnace tube for a petrochemical tubular furnace, which comprises a furnace tube body, an anti-collision protective sleeve is sleeved on the outer side of the furnace tube body, and an anti-abrasion protective sleeve is arranged on the inner side of the furnace tube body. The outer side of the furnace tube body is sleeved with the anti-collision protection sleeve, damage caused by collision between the furnace tube bodies can be reduced, the reinforcing strips are arranged on the anti-collision protection sleeve, the strength of the anti-collision protection sleeve can be enhanced, stronger impact and collision can be resisted, dust impurities and water vapor in air can be prevented from being accumulated on the outer surface side of the anti-collision protection sleeve, and the service life of the furnace tube is prolonged. The inner side of the furnace tube body is provided with the anti-wear protective sleeve, dust impurities and water vapor in air can be prevented from being accumulated on the inner surface side of the furnace tube body, on one hand, abrasion to the surface is prevented, and on the other hand, rusting and corrosion of the furnace tube caused by water vapor accumulation are prevented.

The utility model relates to the technical field of movable vertical perlite expansion furnaces, and discloses a movable vertical perlite expansion furnace inner barrel supporting device which comprises a plurality of supporting devices arranged in the circumferential direction in the axis direction of an inner barrel. The supporting device comprises a first limiting seat and a second limiting seat; the first limiting seat is arranged on the inner cylinder; the second limiting seat is arranged at a fixed position; and the second limiting seat is provided with a limiting area for the first limiting seat to move. The mounting structure has the effect of adapting to deformation of the inner cylinder on the basis of ensuring the mounting stability of the inner cylinder.

The application provides a multilayer C-shaped heat shield for an inductive heating furnace for lunar soil volatile component heating, and belongs to the field of lunar soil exploration. The problem of fast heat transfer and easy formation of vortex defects of a traditional heat shield is solved. The heat shield comprises a heat shield, a connecting column and a notch. A plurality of heat shields are arranged. The plurality of heat shields are arranged at intervals from top to bottom. Each adjacent two heat shields are connected through a group of connecting columns. Each group of connecting columns comprises a plurality of connecting columns arranged at equal intervals in a circle. Each adjacent two groups of connecting columns are arranged in a staggered mode. A notch is arranged on each heat shield. The heat shield is mainly used for lunar soil heating and heat insulation.

The utility model provides a conjoined furnace. The conjoined furnace comprises a slag removal furnace, a separation furnace, a first metal furnace and a second metal furnace, the slag removal furnace and the separation furnace are in common wall connection, the first metal furnace and the separation furnace are in common wall connection, the whole structure is compact in arrangement, energy and refractory material consumption are saved, and the occupied area is small. Metal melts are in direct-current communication in the slag removal furnace, the separation furnace and the first metal furnace, the metal melts with different densities are fully layered due to density difference in the flowing process, the process is short, the latent heat utilization rate is high, energy consumption is low, and continuous operation can be achieved; and an integrally poured lining is arranged in each furnace body, so that the heat preservation effect is good, and the energy consumption is further reduced.

The present invention provides a castable material for a firing furnace, which is capable of eliminating the need for a drying step after casting, and of suppressing alkali attack and physical impacts from furnace contents. The castable material according to the present invention comprises: a refractory raw material mixture containing: 75% by mass or more in total of one or more selected from the group consisting of an alumina raw material, an alumina-silica raw material, and a silicon carbide raw material; and 1% by mass to 15% by mass of silica flour, with a remainder in which a content rate of a CaO component derived from alumina cement is 0.5% by mass or less (including zero); and colloidal silica added to the refractory raw material mixture at an addition rate of 0.5% by mass to 5% by mass in terms of an SiO2 component thereof.

The utility model provides a composite heat insulation layer structure of a graphite digestion furnace. The composite heat insulation layer structure comprises a shell, a heating assembly, a heat insulation assembly and a control system, the shell is provided with a placing groove and a containing cavity, the heating assembly is partially arranged in the placing groove, the control system is arranged in the containing cavity, and the control system is used for controlling the heating assembly; the heat insulation assembly is arranged in the containing groove and located on the outer side of the heating assembly. When the composite heat insulation layer structure is used in the graphite digestion furnace, the overall heat insulation effect is excellent, the temperature of the outer side surface of the shell can be not higher than 40 DEG C and lower than the safe temperature of a human body, the risk of scalding is avoided, heat loss can be well reduced, energy consumption in the same working time is reduced, and the service life is prolonged. And through matched installation of the heating assembly, the heat insulation assembly and the control system, the whole structure is stable.