CN217202521U - Box type precision heat treatment furnace - Google Patents

Abstract

The utility model belongs to the field of heat treatment equipment, specifically disclose a box-type precision heat treatment furnace, aim at solving the relatively poor and great problem of kinetic energy loss of the air current flow homogeneity of its fan impeller air outlet department of current box-type precision heat treatment furnace. According to the box-type precise heat treatment furnace, the air outlet flow guide piece is arranged at the air outlet of the fan impeller, the flow guide channel of the air outlet flow guide piece can guide the air flow thrown out from the air outlet of the fan impeller, and under the guide effect of the flow guide channel, most of the air flow thrown out from the air outlet of the fan impeller can be guided by radial movement of the hearth to move towards the axial direction of the hearth, so that the impact of the air flow on the inner wall of the furnace lining is reduced, the air flow can rotate to move in the air flow channel, the problem of uneven air flow at the air outlet of the fan impeller is solved, the kinetic energy loss of the air flow impacting the inner wall of the furnace lining is reduced, the static pressure efficiency of a centrifugal fan is improved, and the air flow cyclic utilization rate is increased.

Description

Box type precision heat treatment furnace

Technical Field

The utility model belongs to the field of heat treatment equipment, concretely relates to box-type precision heat treatment furnace.

Background

The box-type precise heat treatment furnace has the advantages of small occupied area, capability of meeting the production requirements of some special glass, capability of improving the quality of the glass and the like, and is widely applied to heat treatment of high-performance glass such as optical glass, laser glass and the like. The centrifugal fan is used as an important part of the box-type precise heat treatment furnace, and plays a decisive role in enhancing the convective heat transfer strength of the air flow in the furnace. In the operation process of the heat treatment furnace, air in the furnace is driven to flow under the rotation action of the centrifugal fan, air is sucked from a circular fan air suction inlet in the middle of the furnace body, air is discharged from fan impeller air outlets around the centrifugal fan, air flow is heated by a heating element in the middle of an air flow channel and then reaches a square air inlet at a furnace door, and the air flow enters a main flow area through the square air inlet and then is sucked into the centrifugal fan from the middle, so that the reciprocating circulation of the air flow in the furnace is formed.

Because the centrifugal fan in the stove lacks the part that converts air current kinetic energy into pressure energy, lead to the air current circumference speed of fan wheel air outlet department can't effectively be utilized, circumference kinetic energy can't convert static pressure into, cause fan wheel air outlet static pressure lower, energy loss is serious, and static pressure efficiency reduces, can't reach traditional centrifugal fan's efficiency level. Moreover, the airflow flows out from all the circumferential positions of the centrifugal fan in the heat treatment furnace, the outlet direction is irregular, the flowing uniformity of the airflow is poor, simulation of the airflow flowing characteristic in the box-type precise heat treatment furnace shows that in the airflow circulation process, high-speed airflow thrown out from an impeller is expressed as adherent jet flowing along the inner wall of a furnace lining, the impact on the inner wall of the furnace lining is large, the kinetic energy loss is also large, the entrainment effect of the jet enables a space region between the air outlet of the impeller of the fan and the inner wall of the furnace lining to generate vortex and backflow phenomena, the adherent flowing airflow continuously flows to a furnace door along the inner wall of the furnace lining in a spiral flowing mode of superposing clockwise rotation motion and horizontal axial motion, and after reaching a square air inlet at the furnace door, the adherent flowing enters a furnace effective area and then flows into a fan air suction opening in a reverse rotation flowing mode, and the position is limited by the fan air suction opening, the wind of the square air inlet is gathered at the center, the circulating airflow is difficult to enter the effective area of the hearth at uniform flow and flow velocity, the convective heat transfer strength between the airflow in the furnace and the glass products and between the airflow and the inner wall of the furnace lining is influenced, the heat transfer efficiency in the furnace is reduced, and the temperature uniformity in the furnace is poor.

SUMMERY OF THE UTILITY MODEL

The utility model provides a box-type precision heat treatment furnace, which aims to solve the problems of poor uniformity of air flow and large kinetic energy loss of the air outlet of a fan impeller of the box-type precision heat treatment furnace.

The utility model provides a technical scheme that its technical problem adopted is: the box-type precise heat treatment furnace comprises a furnace body, a heating element, an air guide inner container and a centrifugal fan; the front end of the furnace body is provided with a furnace door, the air guide inner container is arranged in a hearth of the furnace body, an airflow channel is formed between the side wall of the air guide inner container and the inner wall of a furnace lining of the furnace body, the cross section of the airflow channel is annular, and the heating element is arranged in the airflow channel; the front end of the air guide inner container is provided with an air inlet, and the air inlet is used for communicating the inner cavity of the air guide inner container with the air flow channel; the centrifugal fan is arranged at the rear end of the air guide inner container and is provided with a fan air suction opening and a fan impeller air outlet, and the fan air suction opening is communicated with the inner cavity of the air guide inner container; the fan impeller air outlet is provided with an air outlet flow guide part, a smooth flow guide channel is arranged in the air outlet flow guide part, the flow guide channel comprises an airflow inlet end and an airflow outlet end, the airflow inlet end is communicated with the fan impeller air outlet, and the airflow outlet end faces the middle of the airflow channel and is communicated with the airflow channel.

Furthermore, at least two mounting rods are arranged in the airflow channel, the mounting rods are uniformly distributed along the circumferential direction of the air guide liner, and each mounting rod is spirally wound with a heating element.

Further, the air guide inner container comprises a square cylindrical main body and a conical mounting plate arranged at the rear end of the square cylindrical main body, and the cross section of the conical mounting plate is circular; the air inlet is arranged on the side wall of the front end of the square cylindrical main body, and the centrifugal fan is arranged in the central part of the conical mounting plate.

Further, the front end of the air guide inner container is provided with an air rectification accelerating device, and the air rectification accelerating device is positioned on the rear side of the air inlet.

Further, gaseous rectification accelerating device is including sealing the square cowling panel that sets up at wind-guiding inner bag front end, two at least jet holes have been seted up on the square cowling panel, jet hole evenly distributed on square cowling panel.

Further, the two diagonal lines of the square rectifying plate divide the square rectifying plate into four areas, and the jet holes incline towards the outer edge of the area where the jet holes are located.

Further, the inclination angle of the jet hole is 30-75 degrees.

Further, the air outlet flow guide piece comprises at least two flow guide plates arranged at intervals, and a flow guide channel is formed between any two adjacent flow guide plates.

Furthermore, the cross section of the flow guide channel is C-shaped, the air flow inlet end is positioned at the central part of the flow guide channel, and the air flow outlet end is positioned at the edge part of the flow guide channel.

Further, the air flow outlet end is oriented parallel to the length direction of the air flow channel.

The utility model has the advantages that:

(1) according to the box-type precise heat treatment furnace, the air outlet flow guide piece is arranged at the air outlet of the fan impeller, the flow guide channel of the air outlet flow guide piece can guide the air flow thrown out from the air outlet of the fan impeller, and under the guide effect of the flow guide channel, most of the air flow thrown out from the air outlet of the fan impeller can be guided by radial movement of the hearth to move towards the axial direction of the hearth, so that the impact of the air flow on the inner wall of the furnace lining is reduced, the air flow can rotate to move in the air flow channel, the problem of uneven air flow at the air outlet of the fan impeller is solved, the kinetic energy loss of the air flow impacting the inner wall of the furnace lining is reduced, the static pressure efficiency of a centrifugal fan is improved, and the air flow cyclic utilization rate is increased.

(2) This box-type precision heat treatment furnace is through setting up gaseous rectification accelerating device, can make the gaseous inner chamber that can get into the wind-guiding inner bag with bigger speed uniformly after the rectification with accelerateing of flowing from the air current passageway, the flow state of gaseous at the glass front end has effectively been disturbed, the turbulence intensity of air current in gaseous rectification accelerating device and the glass front end space has been improved, the heat transfer effect of forced convection heat transfer in the mainstream district has been reinforceed, and then the heat transfer efficiency in the stove has been improved, make the convection heat transfer effect reinforcing of gaseous and glass front end, thereby improve the temperature of glass front end among the heat treatment process, the difference in temperature at both ends around the glass has been reduced, the effect of precision heat treatment has been guaranteed, glass's quality has been promoted.

(3) Divide into four regions with square cowling panel, and make the efflux hole towards the regional outward flange slope in place, can carry out homodisperse with the air current that air intake and furnace gate department assembled, and the guide is to the internal surface motion all around of wind inner bag, can not only make the air current homogeneity that gets into the furnace active area promote by a wide margin, can also realize air current and furnace lining inner wall convection heat transfer through the efflux hole of slope and strengthen the effect, increase air current and the disturbance of furnace lining inner wall, attenuate thermal boundary layer thickness, promote heat transfer capacity, it is inhomogeneous and cause the glass temperature difference too big to have solved the low temperature air current that the air intake guide comes, the not good problem of quality.

Drawings

FIG. 1 is a schematic sectional view of the present invention;

FIG. 2 is a schematic three-dimensional structure of a square fairing;

fig. 3 is a schematic three-dimensional structure diagram of the air outlet guide member;

FIG. 4 is a cloud of the pressure distribution in the furnace without the gas rectifying and accelerating device and the air outlet guide member;

FIG. 5 is a cloud of the pressure distribution in the furnace with the gas rectifying and accelerating device and the air outlet guide member;

FIG. 6 is a simulation diagram of the flow state of the gas flow in the furnace without the gas rectifying and accelerating device and the air outlet guide member;

FIG. 7 is a simulation diagram of the flow state of the gas flow in the furnace provided with the gas rectifying and accelerating device and the air outlet guide member;

FIG. 8 is a simulation diagram of glass temperature distribution in the furnace without the gas rectifying and accelerating device and the air outlet guide member;

FIG. 9 is a simulation diagram of glass temperature distribution in a furnace provided with a gas rectifying and accelerating device and an air outlet guide member;

labeled as: the air-conditioning furnace comprises a furnace body 100, an air flow channel 210, a heating element 220, an air guide liner 300, an air inlet 310, an air rectification accelerating device 330, a jet hole 331, a conical mounting plate 340, a centrifugal fan 400, an air outlet guide member 500, a guide channel 510, an air flow outlet end 511 and a guide plate 520.

Detailed Description

The present invention will be further described with reference to the accompanying drawings.

The expressions "front", "rear", "upper", "lower", etc. referring to the orientation relation are defined as the direction in which the glass enters the furnace from the door during the heat treatment of the glass as the rear direction. Knowing the rear direction, it can be determined that the direction opposite to the rear direction is the front direction, the direction horizontally perpendicular to the front-rear direction is the left-right direction, and the direction vertically perpendicular to the front-rear direction is the up-down direction.

Referring to fig. 1 and 3, a box-type precision heat treatment furnace includes a furnace body 100, a heating element 220, an air guiding inner container 300 and a centrifugal fan 400; the front end of the furnace body 100 is provided with a furnace door, the air guide liner 300 is arranged in a hearth of the furnace body 100, an airflow channel 210 is formed between the side wall of the air guide liner 300 and the inner wall of a furnace lining of the furnace body 100, the cross section of the airflow channel 210 is annular, and the heating element 220 is arranged in the airflow channel 210; the front end of the air guide liner 300 is provided with an air inlet 310, and the air inlet 310 communicates the inner cavity of the air guide liner 300 with the air flow channel 210; the centrifugal fan 400 is arranged at the rear end of the air guide inner container 300, the centrifugal fan 400 is provided with a fan air suction opening and a fan impeller air outlet, and the fan air suction opening is communicated with the inner cavity of the air guide inner container 300; the fan impeller air outlet is provided with an air outlet flow guide part 500, a smooth flow guide channel 510 is arranged in the air outlet flow guide part 500, the flow guide channel 510 comprises an air flow inlet end and an air flow outlet end 511, the air flow inlet end is communicated with the fan impeller air outlet, and the air flow outlet end 511 faces the middle of the air flow channel 210 and is communicated with the air flow channel 210. The airflow outlet end 511 faces the middle part of the airflow channel 210, so that the partial movement speed of the airflow flowing out of the airflow outlet end 511 along the axial direction of the hearth can be ensured to be greater than the partial movement speed along the radial direction of the hearth, the impact of the airflow on the inner wall of the furnace lining is reduced, and the uniformity of the airflow is improved; the air flow outlet end 511 may partially face the middle of the air flow channel 210, or may fully face the middle of the air flow channel 210, and usually, the air flow outlet end 511 faces an included angle smaller than 45 ° with the air supply direction of the air flow channel 210, where the air supply direction of the air flow channel 210 refers to the direction from the air inlet end to the air outlet end thereof, and also refers to the direction in which the air flow moves in the air flow channel 210; preferably, the direction of the airflow outlet end 511 is parallel to the length direction of the airflow channel 210, that is, the direction of the airflow outlet end 511 is the same as the air supply direction of the airflow channel 210, so that the impact of the airflow on the inner wall of the furnace lining can be reduced to the maximum extent, and the uniformity of the airflow at the air outlet of the fan impeller can reach the optimal state.

According to the box-type precise heat treatment furnace, the air outlet guide part 500 is arranged at the air outlet of the fan impeller, the guide channel 510 of the air outlet guide part 500 can guide the air flow thrown out from the air outlet of the fan impeller, and under the guide effect of the guide channel 510, most of the air flow thrown out from the air outlet of the fan impeller can be guided by radial movement of the hearth to approach axial movement of the hearth, so that the impact of the air flow on the inner wall of the furnace lining is reduced, the air flow rotates to move in the air flow channel 210, the problem of uneven air flow at the air outlet of the fan impeller is solved, the kinetic energy loss of the air flow impacting the inner wall of the furnace lining is reduced, the static pressure efficiency of a centrifugal fan is improved, and the air flow cyclic utilization rate is increased.

The furnace body 100 is a main component of the box-type precision heat treatment furnace and is mainly used for mounting and protecting other components so as to carry out heat treatment on glass loaded in a hearth of the furnace body; the gas flow channels 210 are mainly used for guiding and heating gas in the hearth, the structure of the gas flow channels 210 can be various, and in order to ensure the uniformity of the conveyed gas, the cross section of the gas flow channels 210 is generally in a rotational symmetry structure; the heating element 220 is mainly used for heating glass and gas in the hearth, and the heating element 220 can be various, and generally an electric heating element is selected, for example: resistance bands, resistance wires, thermocouples, and the like; of course, other heating elements or devices may be used.

In order to facilitate installation of the heating element 220 and improve heating uniformity, as shown in fig. 1, at least two installation rods are preferably disposed in the air flow channel 210, each installation rod is uniformly distributed along the circumferential direction of the air guiding inner container 300, and the heating element 220 is spirally wound on each installation rod. Heating element 220 that this embodiment chose for use is the resistance wire, sets up its spiral winding on the installation pole, not only can arrange longer heating element 220 on limited length, promotes the power of this box accurate heat treatment stove, and heating element 220's above-mentioned distribution mode does benefit to the homogeneity that improves heating temperature moreover to the steadiness and the life of heating element 220 installation have been guaranteed. The number of mounting bars is preferably 20.

The air guide inner container 300 is generally a cylindrical structure with one closed end, is mainly used for placing glass to be thermally treated, and forms a circulation channel of gas in the hearth together with the furnace body 100, so that the uniformity of a temperature field in the hearth is improved, and the middle part of an inner cavity of the air guide inner container 300 is generally a hearth effective area. In order to improve the air return efficiency of the centrifugal fan 400, as shown in fig. 1, the air guide liner 300 preferably includes a square cylindrical main body and a conical mounting plate 340 disposed at the rear end of the square cylindrical main body, and the cross section of the conical mounting plate 340 is circular; the air inlet 310 is disposed on a side wall of a front end of the square cylindrical body, and the centrifugal fan 400 is disposed at a central portion of the tapered mounting plate 340. The air guide inner container 300 formed by combining the conical mounting plate 340 and the square cylindrical main body is provided with a transitional contractive curved surface by combining the square section and the circular section, so that gas in the inner cavity of the air guide inner container 300 is favorably sucked into the centrifugal fan 400, the centrifugal fan 400 is favorably used for sending the gas into the gas flow channel 210, the smoothness of gas circulation flow is improved, the temperature field in a hearth is more uniform, and the energy consumption of the centrifugal fan 400 can be reduced.

Preferably, as shown in fig. 1 and fig. 2, a gas rectification acceleration device 330 is disposed at a front end of the air guiding inner container 300, and the gas rectification acceleration device 330 is located at a rear side of the air inlet 310. Set up gaseous rectification accelerating device 330 through the front end at wind-guiding inner bag 300 and carry out the rectification and accelerate the air current to gas, so can make gas get into the inner chamber of wind-guiding inner bag 300 with bigger speed uniformly, the flow state of gas at the glass front end has effectively been disturbed, the turbulence intensity of air current in gaseous rectification accelerating device 330 and the glass front end space has been improved, the heat transfer effect of forced convection heat transfer in the mainstream district has been strengthened, and then the heat transfer efficiency in the stove has been improved, thereby improve the temperature of glass front end among the thermal treatment process, the difference in temperature at both ends around the glass has been reduced, the effect of precision heat treatment has been guaranteed, glass's quality has been promoted.

The gas rectifying and accelerating device 330 is mainly used for rectifying and accelerating the gas entering the front end of the air guiding inner container 300, so that the gas enters the inner cavity of the air guiding inner container 300 at a higher speed and in a more uniform flowing state; the gas rectifying and accelerating device 330 may be a device having both rectifying and accelerating functions, or may be a device including both rectifying and accelerating components, for example: flow equalization plates, gas rectifiers, etc., acceleration components such as: pressure equipment, fans, etc.

In order to save cost and simplify the structure of the device, it is preferable to combine fig. 1 and fig. 2, and the gas rectification accelerating device 330 includes a directional rectifying plate disposed at the front end of the air guiding inner container 300 in a sealing manner, the directional rectifying plate is provided with at least two jet holes 331, and the jet holes 331 are uniformly distributed on the directional rectifying plate. A groove is generally formed at the front end of the air guide inner 300, and a directional rectifying plate is fitted into the groove. Take jet hole 331's direction cowling panel simple structure not only, the preparation is convenient, and the jet hole 331 of equipartition can carry out the rectification to the gas that gets into wind-guiding inner bag 300 front end, can make the fluid cross-section shrink suddenly after the rear side of air intake 310 sets up the direction cowling panel in addition, the velocity of flow increases, thereby can make the air current that gets into the wind-guiding inner bag 300 inner chamber aggravate at the glass front end flow, form the bigger vortex motion of swirl intensity, strengthen the heat transfer intensity between gas and glass, improve the temperature of glass front end among the thermal treatment process, reduce the difference in temperature at both ends around the glass.

The directional rectifying plate is usually made of heat-resistant material, preferably heat-resistant stainless steel material with low cost and convenient processing. The mode that the jet hole 331 is evenly distributed on the directional rectifying plate can be various, for example: equidistant arrangement, array, centrosymmetric distribution, rotational symmetric distribution and the like. The thickness of the direction rectifying plate is usually 5-20 mm, and preferably 5 mm.

Preferably, as shown in fig. 2 again, the two diagonal lines of the square rectifying plate divide the square rectifying plate into four regions, and the jet hole 331 is inclined toward the outer edge of the region. Divide into four regions with square cowling panel, and make jet hole 331 incline towards the outward flange in region, can carry out homodisperse with the air current that air intake 310 and furnace gate department gathered, and the guide is to the internal surface motion all around of wind inner bag 300, can not only make the air current homogeneity that gets into the furnace effective area promote by a wide margin, can also realize air current and furnace lining inner wall convection heat transfer reinforcing effect through the jet hole 331 of slope, increase air current and the disturbance of furnace lining inner wall, attenuate heat boundary layer thickness, promote heat transfer capacity, the problem of the low temperature air current that has solved air intake 310 guide and come is inhomogeneous and cause the glass temperature difference too big, the quality is not good is solved.

On the basis, in order to achieve the optimal flow equalization and heat exchange effects, the inclination angle of the jet hole 331 is preferably 30-75 degrees. The optimal inclination angle is 45 °, so that the airflow can be uniformly guided and diffused to the inner wall surface around the air guide liner 300.

The gas rectification accelerating device 330 can not only greatly improve the uniformity of gas flow entering the effective area of the hearth, but also realize the heat convection strengthening effect of the gas flow and the inner wall of the furnace lining through the inclined jet holes 331, the diameter of the jet holes 331 is usually 10-30 mm, the influence of the diameter range on the temperature uniformity of the effective area of the hearth is small, and the diameter of the jet holes 331 is preferably 20 mm; the length of the jet hole 331 is usually 5-15 mm, preferably 12mm, and the jet hole 331 in an inclined state is easily prevented from being embedded into a nearby part;

the air outlet guide piece 500 is mainly used for guiding air flow thrown out from the air outlet of the fan impeller, and simultaneously reduces the running resistance of the centrifugal fan 400, so that the air flow is sent out from the air flow outlet end 511 towards the middle part of the air flow channel 210, the impact of the air flow on the inner wall of the furnace lining is reduced, the problem of uneven air flow at the air outlet of the fan impeller is solved, the kinetic energy loss of the air flow impacting the inner wall of the furnace lining is reduced, the static pressure efficiency of the centrifugal fan is improved, and the air flow circulation utilization rate is increased. The air outlet guide 500 may have various structures, for example: tubular structures, disk structures, plate structures, and the like. Preferably, the air outlet guide member 500 includes at least two guide plates 520 arranged at intervals, and a guide channel 510 is formed between any two adjacent guide plates 520.

Preferably, the air outlet flow guiding member 500 is formed by three concentric circular-disk-shaped flow guiding plates 520 with different diameters to form two flow guiding channels 510, so that the high-speed airflow at the air outlet of the fan impeller is transited from the radial flow of the hearth to the axial flow approaching the hearth, thereby reducing the loss of the air outlet of the fan impeller caused by the sudden increase of the space and the momentum loss caused by the impact of the high-speed airflow on the inner wall of the furnace lining on the one hand, and blocking the vortex close to the fan wheel cover caused by the entrainment of the wall-attached jet flow on the other hand.

In order to achieve a better flow guiding effect and reduce the loss of kinetic energy caused by the impact of the gas flow on the inner wall of the furnace lining as much as possible, it is preferable that the flow guiding plate 520 is a ring structure which is rotationally symmetric along the rotation axis of the centrifugal fan 400, and the section of the flow guiding plate 520 is cut along the radial direction of the centrifugal fan 400, and the section is arc-shaped, as shown in fig. 1 and 3; specifically, the cross section of the flow guide channel 510 is "C" shaped, the air inlet end is located at the central portion of the flow guide channel 510, and the air outlet end 511 is located at the edge portion of the flow guide channel 510.

The baffle 520 may be made of a variety of materials, preferably heat resistant stainless steel; specifically, the thickness of the flow guide plate 520 is 2mm, the arc radius of the cross section of the flow guide plate is 60-100 mm, preferably 80mm, and is slightly smaller than the distance from the air outlet of the fan impeller to the heating element 220; compared with the guide plate 520 with a straight line section or straight cone section structure, the guide channel 510 formed by the arc-shaped guide plate 520 can smoothly guide the radial airflow at the air outlet of the fan impeller to the airflow channel 210, so that the kinetic energy loss caused by the direct impact of the airflow on the inner wall of the furnace lining is reduced, the reverse flow of the airflow in the airflow channel 210 is blocked, and the performance of the centrifugal fan 400 is effectively improved. Considering that the impeller is a part rotating at a high speed, the guide plate 520 is a static part, in order to prevent severe vibration caused by dynamic and static interference between the rotation of the impeller and the guide plate 520 and strong abrasion between the rotation of the impeller and the guide plate, a certain radial gap is kept between the guide plate 520 and the impeller, the radial gap is usually controlled to be 2-5 mm, preferably 2mm, and the outlet end faces of the guide plate 520 and the impeller cover are usually on the same horizontal line; the end of the flow guide channel 510 adjacent the fan wheel outlet is an airflow inlet end, the end remote from the fan wheel outlet is an airflow outlet end 511, and the airflow outlet end 511 is generally horizontally aligned with the front disk. The static pressure of the air outlet of the fan impeller is increased from original 44.513Pa to 246.131Pa by analog simulation, and the air outlet guide piece 500 has a diffusion effect. The air flows in the guide channels 510 do not interfere with each other, and flow along the inner wall of the furnace lining to the furnace door, reach the air inlet 310 near the furnace door, and are acted by the low pressure from the air suction inlet of the fan, and the air flow in the air inlet 310 mainly flows to the centrifugal fan 400 in a state of being concentrated in the center.

In the whole circulating flow process of the air flow in the furnace, the air flow is guided to smoothly enter the air flow channel 210 by means of the air outlet guide piece 500 and through the adjustment and diffusion effects of the air flow direction of the air outlet of the fan impeller, uniformly heated in the air flow channel 210 and then reaches the air inlet 310, and then enters the effective area of the hearth through the deviation and acceleration of the inclined jet hole 331 at the position, so that the circulating flow smoothness of the whole air flow is improved, and the uniformity of a temperature field is improved.

Examples

Utilize the utility model provides a box accurate heat treatment furnace sets up under the condition of gaseous rectification accelerating device 330 and air-out water conservancy diversion piece 500, carries out emulation heat treatment to three glasses of placing on the three-layer frame plate, and three glasses are from last down numbering in proper order for #1, #2, # 3. In the heat treatment process, the structure of the pressure distribution in the furnace is shown in fig. 5, the simulation result of the flow state of the air flow in the furnace is shown in fig. 7, the simulation result of the temperature distribution of the glass in the furnace is shown in fig. 9, and the maximum temperature difference value of the glass is shown in table 1 below.

Comparative example

Utilize other structures with the utility model provides a box-type precision heat treatment furnace is the same, under the condition (being equivalent to current box-type precision heat treatment furnace) that does not set up gas rectification accelerating device 330 and air-out water conservancy diversion spare 500, carries out emulation thermal treatment to three glasses of placing on the three-layer frame plate, and three glasses are from last to down numbering in proper order #1 ', #2 ', #3 '. In the heat treatment process, the structure of the pressure distribution in the furnace is shown in fig. 4, the simulation result of the flow state of the air flow in the furnace is shown in fig. 6, the simulation result of the temperature distribution of the glass in the furnace is shown in fig. 8, and the maximum temperature difference value of the glass is shown in table 1 below.

TABLE 1 maximum temperature Difference value Δ T of glasses

As can be seen from fig. 4 and 5, when the air outlet guide member 500 is not provided, the pressure in the furnace is concentrated at the rear end of the furnace chamber close to the centrifugal fan 400, the impact on the inner wall of the furnace lining is large, and the kinetic energy loss is also large; under the condition that the air outlet flow guide piece 500 is arranged, the pressure in the furnace is uniformly distributed.

As can be seen from fig. 6 and 7, due to the bias of the centrifugal fan 400 and the blocking of the oven door, when the gas rectification accelerating device 330 and the air outlet guide member 500 are not provided, the air flow entering the main flow area at the front end of the air guide liner 300 during the circulation process may not flow uniformly, the air flow velocity distribution may not be uniform, the air flow disturbance may not be severe, the strong convection strength between the air flow and the front end of the glass may be relatively weak, and the heat exchange may not be sufficient; under the condition that the gas rectifying and accelerating device 330 and the air outlet guide member 500 are arranged, most of air flow thrown out from the air outlet of the fan impeller can be guided to move close to the axial direction of the furnace chamber from the radial movement of the furnace chamber under the guide effect of the air outlet guide member 500, so that the air flow can rotate and move in the air flow channel 210, the problem of uneven air flow at the air outlet of the fan impeller is solved, the kinetic energy loss of the air flow impacting the inner wall of a furnace lining is reduced, the static pressure efficiency of a centrifugal fan is improved, and the air flow circulation utilization rate is increased; meanwhile, the gas can uniformly enter the inner cavity of the air guide inner container 300 at a higher speed, the flowing state of the gas at the front end of the glass is effectively disturbed, the turbulence intensity of the gas flow in the gas rectification accelerating device 330 and the space at the front end of the glass is improved, the heat exchange effect of forced convection heat transfer in the main flow area is enhanced, and the heat exchange is more sufficient.

It can be seen from fig. 8 and 9 and table 1 that, under the condition of having set up gaseous rectification accelerating device 330 and air-out water conservancy diversion piece 500, the glass maximum temperature difference value Δ T of the interior thermal treatment of stove is obviously less than the condition of not setting up gaseous rectification accelerating device 330 and air-out water conservancy diversion piece 500, explains the utility model provides a box precision heat treatment stove can effectively reduce the front and back end difference in temperature among the glass thermal treatment process, improves the homogeneity of the precision heat treatment of glass, and the average difference in temperature of glass product has reduced 42.1%.

Claims (10)

1. The box-type precise heat treatment furnace comprises a furnace body (100), a heating element (220), an air guide inner container (300) and a centrifugal fan (400); the front end of the furnace body (100) is provided with a furnace door, the air guide inner container (300) is arranged in a hearth of the furnace body (100), an airflow channel (210) is formed between the side wall of the air guide inner container (300) and the inner wall of a lining of the furnace body (100), the cross section of the airflow channel (210) is annular, and the heating element (220) is arranged in the airflow channel (210); the front end of the air guide inner container (300) is provided with an air inlet (310), and the air inlet (310) is used for communicating the inner cavity of the air guide inner container (300) with the air flow channel (210); the centrifugal fan (400) is arranged at the rear end of the air guide inner container (300), the centrifugal fan (400) is provided with a fan air suction opening and a fan impeller air outlet, and the fan air suction opening is communicated with the inner cavity of the air guide inner container (300); the method is characterized in that: fan wheel air outlet department is provided with air-out water conservancy diversion spare (500), be equipped with smooth water conservancy diversion passageway (510) in air-out water conservancy diversion spare (500), water conservancy diversion passageway (510) include air current entrance point and air current exit end (511), the air current entrance point communicates with fan wheel air outlet, air current exit end (511) are towards the middle part of air current passageway (210) and communicate with air current passageway (210).

2. The box-type precision heat treatment furnace according to claim 1, characterized in that: at least two mounting rods are arranged in the airflow channel (210), the mounting rods are uniformly distributed along the circumferential direction of the air guide inner container (300), and each mounting rod is spirally wound with a heating element (220).

3. The box-type precision heat treatment furnace according to claim 1, characterized in that: the air guide inner container (300) comprises a square cylindrical main body and a conical mounting plate (340) arranged at the rear end of the square cylindrical main body, and the cross section of the conical mounting plate (340) is circular; the air inlet (310) is arranged on the side wall of the front end of the square cylindrical main body, and the centrifugal fan (400) is arranged in the central part of the conical mounting plate (340).

4. The box-type precision heat treatment furnace according to claim 3, characterized in that: the front end of the air guide inner container (300) is provided with an air rectification accelerating device (330), and the air rectification accelerating device (330) is positioned on the rear side of the air inlet (310).

5. The chamber type precision heat treatment furnace as claimed in claim 4, wherein: the gas rectification accelerating device (330) comprises a square rectifying plate which is arranged at the front end of the air guide inner container (300) in a sealed mode, at least two jet holes (331) are formed in the square rectifying plate, and the jet holes (331) are uniformly distributed on the square rectifying plate.

6. The box-type precision heat treatment furnace according to claim 5, characterized in that: the two diagonal lines of the square rectifying plate divide the square rectifying plate into four regions, and the jet hole (331) inclines towards the outer edge of the region where the jet hole is located.

7. The box-type precision heat treatment furnace according to claim 6, wherein: the inclination angle of the jet hole (331) is 30-75 degrees.

8. The box-type precision heat treatment furnace according to any one of claims 1 to 7, characterized in that: the air outlet flow guide piece (500) comprises at least two flow guide plates (520) arranged at intervals, and a flow guide channel (510) is formed between any two adjacent flow guide plates (520).

9. The box-type precision heat treatment furnace according to claim 8, wherein: the cross section of the flow guide channel (510) is C-shaped, the air flow inlet end is positioned at the central part of the flow guide channel (510), and the air flow outlet end (511) is positioned at the edge part of the flow guide channel (510).

10. The box-type precision heat treatment furnace according to claim 9, wherein: the gas flow outlet end (511) is oriented parallel to the length direction of the gas flow channel (210).

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