A kind of drying oven for reducing heavy castings blowhole defect
Cast casting technical applications are the utility model is related to, particularly relate to a kind of reduction invasive gas of heavy castings
The method and drying oven of hole defect.
In order to reduce the blowhole defect of casting, it is however generally that, casting mold is required for carrying out surface drying processing.Surface drying processing
Method mainly has following several：（1）Mo(U)ld face carries out flame baking.Advantage：Large scale equipment is not needed, it is simple to operate；Shortcoming：
Mo(U)ld face baking is insufficient, and baking surface layer thickness is relatively thin, while even if skin drying, but due to not having inside casting mold
To baking, moisture is larger, due to suction-operated, also can gradually make the surface moisture absorption；（2）Using coal gas（Natural gas）Stove enters to casting mold
Row baking.Advantage：Casting mold surface drying, efficiency high are mainly carried out using convection current and conduction pattern；Shortcoming：The position temperature near apart from flame
Degree is high, easily casting mold is locally burnt, and each position drying degree of casting mold is inconsistent, if the superposition of multilayer casting mold is placed, effect is more
Difference.（3）Toasted using resistance furnace.Advantage mainly carries out casting mold surface drying, efficiency high using radiation and conduction pattern；Shortcoming：
The spot temperature near apart from resistance wire is high, easily casting mold is locally burnt, and the position drying effect remote apart from resistance wire is poor, if
The superposition of multilayer casting mold is placed, and each position drying effect of casting mold is worse.
Utility model content
In order to solve the above technical problems, the utility model provides a kind of drying for reducing heavy castings blowhole defect
Stove, using special structure design and arrangement, the skin drying of casting mold is carried out by the way of hot air circulation, can not only be solved
Mo(U)ld face drying it is inconsistent the problem of, and multilayer casting mold superposition place cured effect substantially with individual layer cured effect one
To realize above-mentioned technical purpose, used technical scheme is：
A kind of drying oven for reducing heavy castings blowhole defect, drying oven are connected respectively by the side walls of both sides
The fire door and rear wall and furnace roof composition at two side walls both ends, are provided with chassis in drying oven, are provided with and are used in the top of chassis
The table top of casting mold is placed, the superjacent air space of table top is operating room in stove, and described table top is hollow out table top, in two side walls
Heater and the centrifugal high pressure fan being arranged on below heater are installed respectively, are respectively equipped between chassis and two side walls
One is vertically arranged dividing plate, and gap is provided between the upper end of dividing plate and furnace roof, and side and the side walls of dividing plate surround return airway,
Fitting sets U-shaped airduct on its opposite side, and the both ends of dividing plate are pushed up provided with fire door and rear wall respectively, the exhausting of centrifugal high pressure fan
Mouthful corresponding return airway is set, and its blowing mouth is by the air inlet of U-shaped airduct, from multiple exhaust vents of U-shaped airduct to table top bottom
Portion, drying furnace door and Hou Qiang positions blowout hot blast.
U-shaped airduct described in the utility model is by being horizontally set on horizontal airduct and being vertically disposed on horizontal airduct two
The vertical airduct composition at end, the both ends sealing of horizontal airduct, and the side of the blowing mouth in corresponding centrifugal high pressure fan offers
Air inlet, one end sealing of vertical airduct, the other end are connected with horizontal airduct, are all provided with horizontal airduct and two vertical airducts
There are multiple exhaust vents, the exhaust vent of horizontal airduct corresponds to the setting of table top bottom space, and the exhaust vent of two vertical airducts is right respectively
Fire door space and Hou Qiang spaces is answered to set.
The top of dividing plate described in the utility model is provided with regulation dividing plate upper end and the air port adjustable plate of furnace roof gap length.
Between the utility model wall, between wall and chassis, used between fire door and wall, between chassis and fire door
Asbestos carry out soft seal.
Heater described in the utility model is resistance band heater.
Exhaust vent described in the utility model is provided with the swivelling cover that can change exhaust vent size.
The beneficial effects of the utility model are：
1st, by the air after heating by centrifugal high pressure fan respectively from placing the hollow out table top bottom of casting mold, drying oven
Fire door and Hou Qiang positions are heated into drying oven operating room to casting mold, do not stop to heat using endless form, surface treatment effect
Rate is high, ensureing casting mold, each position drying degree is consistent, meanwhile, casting mold is not influenceed stacks heating.
2nd, realized by the drying oven of special construction and mo(U)ld face is heated, dried using indirect hot blast form, no
Directly heat makes the barbecue of drying abundant, and does not influence the overall structure of original drying oven, ensures the recycling of hot blast,
Save the energy.
3rd, realize that the heating to different size casting mold is adjusted by air port adjustable plate, make drying oven be adapted to the different numbers of plies different
The casting mold of size.
4th, carried out using asbestos between wall, between wall and chassis, between fire door and wall, between chassis and fire door
Soft seal, heat losses are not only prevented, also with insulation effect, whole drying oven just can be completed big temperature with less heat
Brief description of the drawings
Fig. 1 is the utility model drying oven cross-sectional view；
Fig. 2 is the utility model drying oven representative side section view；
Fig. 3 is the structural representation of the utility model exhaust vent；
Fig. 4 is the utility model chassis and side walls sealing structure enlarged diagram；
Fig. 5 is the utility model chassis and rear wall sealing structure enlarged diagram；
Fig. 6 is the utility model chassis and oven door sealing structure enlargement diagram；
Fig. 7 is the U-shaped airduct dimensional structure diagram of the utility model；
In figure：1st, thermocouple, 2, air port adjustable plate, 3, side walls, 4, heater, 5, U-shaped airduct, 51, horizontal airduct,
52nd, vertical airduct, 6, swivelling cover, 7, centrifugal high pressure fan, 8, sealing dividing plate A, 9, exhaust vent, 10, chassis, 11, sealing dividing plate
B, 12, casting mold, 13, sealing dividing plate C, 14, fire door, 15, rear wall, 16, furnace roof, 17, table top, 18, dividing plate, 19, air inlet.
A kind of method for reducing heavy castings blowhole defect, hangs heater in two side walls of drying oven, adds
Hot device heats to air, the air after heating by centrifugal high pressure fan respectively from table top bottom, drying furnace door and after
Wall position is heated into drying oven operating room to casting mold, while hot-air dissipates with the cold air in moving chamber and casting mold
The moisture issued, so as to realize the hot air circulation Convective Heating of casting mold, ensures casting from operating room's overhead reflux to side walls
The uniformity of each position surface drying effect of type.
Described heater can select resistance band heater.
A kind of drying oven for reducing heavy castings blowhole defect：
First, heater is installed in two side walls of drying oven, a stainless steel is set between heater and casting mold
Dividing plate, the both sides of dividing plate are close to fire door and rear wall, close and surround return airway between heater, are close to stainless steel separator design
1 U-shaped airduct, the exhaust vent of some adjustable sizes, the exhaust vent face chassis of U-shaped airduct horizontal direction are driven on U-shaped airduct
Air channel, U-shaped airduct vertical direction air outlet blows to rear wall and fire door respectively, the air channel upper surface of chassis be middle hollow out not
Become rusty steel plate table top.
Secondly, two centrifugal high pressure fans are designed, are respectively installed to two sides of drying furnace body, it is desirable to per Fans
Air quantity is enough to ensure that 2 minutes interior energies by operating room's air circulation once；Require that centrifugal high pressure fan installs stay-warm case additional simultaneously, reduce
Thermal loss and reduction noise, the air inlet of centrifugal high pressure fan correspond to return airway setting, extract return air, its air outlet
Irrigate hot blast into U-shaped airduct, the behind of U-shaped airduct can be that an air inlet can also be multiple or be opened in U-shaped airduct bottom side
If air inlet, as shown in figure 1, the air inlet has the wind inlet channel for enclosing and being set as, the number and size of air inlet are entered on demand
The amount of wind is configured.
Again, set 6 thermocouples to carry out 6 thermometrics in drying oven operating room, monitor the temperature at each position, meet ±
5 DEG C of control range requirement.
Finally, whole electric-control system and temperature control system are controlled using PLC, can set different process road according to casting mold size
In addition, externally being radiated to reduce drying oven, heat-insulating property is improved, two side walls and rear wall are placed directly on ground
On, the front portion of chassis is also provided with sealing dividing plate C, ensures to form sealing cavity between chassis and wall, can fill out and set in sealing cavity
There are asbestos, effectively prevent from heat loss caused by the ventilative flowing with gas of furnace bottom.Simultaneously between wall, wall and chassis it
Between, soft seal is carried out using asbestos between fire door and wall, between chassis and fire door, ensures airtight, the soft seal of asbestos
It is to be realized by the way that asbestos are wrapped on the outside of sealing dividing plate.
In addition, U-shaped airduct only blows out hot blast by exhaust vent, it is by being horizontally set on horizontal airduct and being respectively perpendicular setting
Vertical airduct at horizontal airduct both ends forms, and horizontal airduct and the selection of vertical airduct are square, and its back side is attached on dividing plate, i.e.,
The heat on dividing plate can be drawn, is easily installed again, the both ends sealing of horizontal airduct, and in the blowing mouth of corresponding centrifugal high pressure fan
Side offer air inlet, one end sealing of vertical airduct, the other end connects with horizontal airduct, vertical in horizontal airduct and two
Multiple exhaust vents are equipped with straight airduct, the exhaust vent of horizontal airduct correspond to table top bottom space and set, two vertical airducts
Exhaust vent corresponds to fire door space and Hou Qiang spaces and set respectively, and exhaust vent is provided with the rotation that can change exhaust vent size
Lid, swivelling cover open or close exhaust vent by way of rotation, can control fire door, rear wall by swivelling cover, chassis lower section is not
With air output, can be by adjusting the wind of dividing plate upper end and furnace roof gap length to ensure the hot air circulation time in operating room
Mouth adjustable plate realizes the change of return air air quantity.
It is as follows that air cooking flow is carried out by dryer：After heater heats to air, centrifugal high pressure fan will
Air after heating is pressed into U-shaped airduct, and the horizontal exhaust vent of U-shaped airduct is blown into chassis air channel, hot blast from Intermediate Gray mesh not
Rust steel table top is blown into drying oven operating room and carries out air cooking to casting mold, the vertical exhaust vent of U-shaped airduct blow to respectively rear wall and
Fire door position, ensure that each spot temperature in drying oven operating room is consistent.Hot-air is while casting mold is toasted with moving chamber
The moisture that cold air and casting mold come out from chamber bottom converge to top, be then refluxed for heater and stainless steel every
Plate shape into heating region heated.In operating room, top design has air port adjustable plate that air quantity is adjusted, and U-shaped airduct is opened
If exhaust vent air quantity can also be adjusted as needed.It is real by controlling hot blast flow direction and adjusting the size of air quantity
The hot air circulation Convective Heating of existing casting mold, operating room's temperature difference are controlled in the range of ± 5 DEG C, and then ensure each position temperature difference control of casting mold
System ensure that the uniformity of casting mold surface drying in the range of ± 5 DEG C.
Equipment operation basic procedure is：Enter chassis → pass fire door → machine that blows in → open and heat → and stop heating → Blowing stopper → to open
Fire door → go out chassis.
Large-scale mould drier has been made using the art of this patent, work chamber size 6000mm × 3000mm × 2500mm,
150 DEG C of operating temperature, precision ± 5 DEG C.
Casting mold 5132889,4103051 is toasted using this patent, statistical correlation data, and toasted with resistance furnace
As a result it is analyzed, statistical result is as shown in the table.
The data statistic of table 1
As can be seen from Table 1：The drying oven manufactured using utility model patent is toasted to casting mold, casting
5132889 porositys are down to 17.5% from 86.7%, and the porosity of casting 4103051 is down to 16.3% from 81.1%, and gas hole defect is significantly
Reduce, illustrate that the drying oven cured effect of this patent manufacture is far superior to the cured effect of conventional, electric-resistance stove.