DE19847299C1 - Pass-through microwave oven has height adjustable base plate, air outlet holes next to radiation windows, air regulators, microwave guide and distribution devices for each window - Google Patents

Abstract

The oven has oven modules (12) forming heating zones with semicircular housings, each carrying at least one microwave source (30) at a radiation window (31) and contg. a base plate (26) with holes or slots (28) forming secondary radiators. A transport mechanism has a belt (34) or rollers. The base plate is height adjustable and air outlet holes (35) are arranged next to the window. Each radiation source is combined with an air regulator (45) and the window has associated microwave guide and distribution devices (52).

Description

The invention relates to a continuous microwave oven Oven modules forming heating zones in a row are arranged one behind the other, each oven module Has housing with a circular housing shell, wherein on at least one microwave Radiation source provided on an associated radiation window is, a sheet metal base in the respective housing jacket is arranged, the holes forming with secondary radiators or Slots is formed, and wherein in the microwave Continuous furnace a transport device is provided by is formed by a conveyor belt or by transport rollers, the conveyor belt forming a common plane Sheet metal shelves of the oven modules are resting or in the holes of the Sheet metal transport rollers are stored, which is a common Form level, according to patent 197 38 882.

A continuous microwave oven is known from US Pat. No. 4,746,968. oven modules forming the heating zones in a row  are arranged one behind the other, each oven module Has housing with a housing jacket, the respective Housing jacket at least one microwave radiation source is provided, one in the respective housing shell Sheet metal bottom is arranged, which is formed with holes, and being through the continuous microwave oven The conveyor belt extends through it. In this well-known The perforated sheets do not serve as a continuous microwave oven Secondary radiators, d. H. it does not affect the reflected microwave radiation of the radiation source causes the perforated plates serve as thermal radiators.

From DE-B: E. Pehl "Microwave Technology", Vol. 1, 1988, Dr. A. Hüthig-Verlag Heidelberg, pages 148-151, are perforated sheets in resonators, which are e.g. B. around microwave boiler rooms acts, known. These perforated plates are used to couple in Microwave energy in the microwave boiler room.

DE-GM 18 18 464 discloses a continuous microwave oven with a high frequency closed on all sides, elongated work space and a conveyor belt for that too treating objects. In this known microwave Continuous furnace pass through the objects in the course of the movement of the Conveyor belt successively different fields different frequency. In the case of a drying process the working space is in the direction of movement of the objects Microwave energy increasing frequency and in the case of a Warming process will work in Direction of travel of the objects with microwave energy falling frequency. The microwave energy of the Radiation source is there, for example, via coupling slots in the Furnace chamber fed, d. H. the perforated plate also serves here  only the coupling of the microwave energy into the Working area of the microwave continuous oven.

From EP 0 016 699 A1 is a continuous microwave oven known who has antennas in his furnace room. This Antennas are used to scatter the microwave field. The Antennas therefore influence the microwave Field distribution; Perforated sheets are not provided there. This well-known continuous microwave oven is on its two end sections facing away from each other with a Radiation absorber module provided.

Continuous microwave ovens, each provided with a radiation absorber module at their two opposite end sections, are also known from DE-Z: iew 49, 1991, Vol. 3, pages 149-155, "Microwave Heating - Application in Industry" known by G. Orth and J. Walter. Figure 2 and the associated description there disclose radiation absorber modules which have ferrites which are adjacent to one another in order to prevent microwave radiation which is hazardous to personnel from escaping from the continuous microwave oven.

A continuous microwave oven is also known from DE 196 43 989 A1 known. This known continuous microwave oven has one circular casing shell. A continuous microwave oven with a circular housing jacket is also known from EP 0 136 453 A1 known.

DE 40 15 639 A1 describes one with electromagnetic Waves, especially microwaves, heating device. The microwaves are generated in a magnetron and over a waveguide with an even distribution of one Heat exchange chamber supplied. The heat exchange chamber will  Air fed through a blower and by direct impact to the microwave radiation or by contact with an in the heat exchange chamber arranged absorber element Heat exchange heated and then to heat one Dissipated space. With the help of this known heater can be a good heating condition, good air conditioning as well achieve heat generation without environmentally harmful residues.

The invention is based, such Continuous microwave oven to develop such that  mechanical, electrical and microwave technology comparatively simple way of field optimization and Energy distribution in the furnace is further improved possible.

This object is achieved by the features of Claim 1, d. H. solved in that the sheet metal floors of Furnace modules are adjustable in height and / or that for Radiation window of the respective microwave radiation source in the Housing shell air outlet holes are adjacent, the respective radiation source with an air regulator is combined and / or that the radiation window of the respective Microwave radiation source inside the corresponding Oven module a microwave steering and distribution device assigned.

Due to the height adjustment of the sheet metal shelves of the oven modules it is simply possible to place the inside of the continuous furnace Improve field optimization and energy distribution. Out of it results in an increase in the efficiency of the Continuous microwave oven according to the invention. The same purpose d. H. an increase in efficiency, it is useful if the Continuous microwave oven according to the invention for the radiation window the respective microwave radiation source in the housing jacket Air outlet holes are adjacent, the respective Radiation source is combined with the air regulator. With the help of the air regulation device it is easily possible the air heated by the microwave radiation source is targeted, d. H. with a desired quantity, through which To direct air outlet holes into the interior of the continuous furnace and in this way at least part of the waste heat of the respective Microwave radiation source in a continuous furnace to take advantage of. This is - as is immediately clear - one corresponding overall efficiency increase possible. A  Improvement of field optimization and energy distribution in the Inside of the continuous furnace is also possible in that the Radiation window of the respective microwave radiation source in the Inside of the corresponding oven module the one mentioned Microwave steering and distribution device is assigned. With With the help of said microwave steering device it is, for example. possible from the radiation window into the interior of the Continuous oven emerging microwave radiation to give the desired twist in order to optimize the field achieve.

In the continuous microwave oven according to the invention, the Sheet metal floors of the individual oven modules separated from each other be adjustable in height, but it is preferred if the Sheet metal floors of the oven modules are simultaneously height-adjustable. The Sheet metal shelves can also be tiltable.

The sheet metal shelves of the microwave continuous oven according to the invention can be flat. However, it is also possible that the sheet metal floors are convex or concave to in this way a lens effect of the microwaves and thus a corresponding field optimization in the interior of the furnace in the ratio to the material to be heated in the continuous microwave oven achieve.

It is useful if the respective microwave Radiation source is provided in a radiation source housing, which spans the radiation window and the air outlet holes or bridged when on the radiation source housing for cooling the A microwave blower source can be arranged, and if the radiation source housing to form the Air regulating device with an outlet opening Have regulator. The regulator can act as  Sliding or be designed as a rotary control member. With help of the regulator provided on the radiation source housing it is easy to put the amount of air coming from the blower into one determined, flowing through the air outlet holes Air volume fraction and one from the outlet opening of the Air regulating device to divide emerging partial flow. According to the size of the light set as desired Exit cross section of the outlet opening is the Air outlet holes flowing through and entering the furnace interior Air proportion regulated.

The steering device assigned to the radiation window can be used as two or three-dimensional steering body can be formed. At A two-dimensional steering body can be a flat one or be a curved plate element. At a three-dimensional steering body can be a cone to act a pyramid or the like. The steering body can be adjusted or adjustable in relation to the associated radiation window be trained. With a three-dimensional steering body can e.g. the apex angle of the cone or the pyramid be adjustable. This is a desired field optimization and Energy distribution realizable.

The steering body can be made of a highly conductive, reflective metal exist. It can also be made from one variable conductivity, partially absorbent Ceramic material exist. This can be SiC, ceramic-bonded SiC, ferrite material or the like Trade microwave-absorbing ceramics or glass. With such materials is partial microwave absorption possible.  

It is also the case with the continuous microwave oven according to the invention possible that on the housing shell of the respective oven module Waveguide channel is provided, which with the microwave Radiation source is combined, and that the housing shell along the waveguide channel with secondary radiators Recesses is formed. The said waveguide channel expediently extends in the circumferential direction of the Housing shell of the furnace module. The one in the casing trained recesses assigned to the waveguide channel can be slit-shaped, cruciform or the like.

The waveguide channel can extend around the housing jacket of the stretch around the respective oven module, but it is also possible that the waveguide channel along only one Sections of the circumference of the housing shell extends.

The recesses can be at least along one Extend section of the associated waveguide channel, however, they can extend along the entire length of the extend respective waveguide channel. For the desired Setting the field distribution in the respective oven module can mentioned recesses in the housing jacket or in the waveguide channel a voting device may be assigned. This Tuning device can be formed by at least one slide his. This slide is, for example, a so-called Short circuit slider.

Further details, features and advantages result from the following description of one in the drawing illustrated embodiment of the invention Continuous microwave oven. Show it:  

Fig. 1 is a partially cutaway front view of an oven module of the continuous microwave oven, and

Fig. 2 shows schematically in a view from above an oven module with a microwave radiation source and an associated waveguide channel on the housing shell of the oven module.

Fig. 1 shows a continuous microwave furnace 10 and an oven module 12 of the continuous microwave furnace 10, the furnace modules are arranged in a row one behind the other 12 and the continuous microwave furnace form heating zones 10. Each oven module 12 of the continuous microwave oven 10 has a housing 13 with a circular housing jacket 14 . On the axially facing end faces 16 of the housing jacket 14 of the respective oven module 12 , ring flanges 18 are provided, by means of which adjacent oven modules 12 can be connected to one another to form the continuous microwave oven 10 . Each ring flange 18 is formed with support members 20 and with mounting holes 22 . The fastening holes 22 are provided equidistantly along a pitch circle 23 . Only some of these mounting holes 22 are illustrated in the figure.

In the interior of the respective oven module 12 , bearing elements 24 are provided which protrude from the inside of the housing jacket 14 . The bearing elements 24 serve to support a sheet metal base 26 which is associated with the respective furnace module 12 and is provided with holes 28 . The height of the respective sheet metal base 26 is adjustable. This height adjustability of the respective sheet metal base 26 is illustrated by the double arrow 29 .

At least one microwave radiation source 30 is provided on the housing jacket 14 of the respective oven module 12 of the continuous microwave oven 10 on an associated radiation window 31 formed in the housing jacket 14 .

By the continuous microwave furnace 10, a conveyor 33, extending therethrough which serves to support the in continuous microwave furnace 10 material to be treated. A transport belt 34 forming the transport device 33 is illustrated in the figure. The transport device 33 can also be formed by transport rollers which are mounted in the holes 28 in the sheet metal bottoms 26 of the oven modules 12 of the continuous microwave oven 10 .

The conveyor belt 34 lies on the sheet metal shelves 26 of the oven modules 12 of the continuous microwave oven 10 which form a common plane.

14 air outlet holes 35 are adjacent to the radiation window 31 of the respective microwave radiation source 30 in the housing shell. The respective microwave radiation source 30 is provided in a radiation source housing 37 which covers the radiation window 31 and the air outlet holes 35 . For cooling the microwave radiation source 30 , which can be formed by a commercially available magnetron, a blower 39 is arranged on the radiation source housing 37 . The radiation source housing 37 has an outlet opening 41 , with which a regulating member 43 is assigned. The regulating element 43 can be formed by a slide regulator element or by a rotary regulator element. The regulating member 43 forms, together with the outlet opening 41 in the radiation source housing 37, an air regulating device 45 , with the aid of which it is possible to selectively direct the air flow sucked in by the blower 39 , which flows around and cools the microwave radiation source 30 , into a first partial flow flowing through the air outlet holes 35 and into a second partial flow flowing through the air regulating device 45 . The first partial flow is indicated by arrows 47 and the second partial flow is indicated by arrow 49 .

A microwave steering device 52 is assigned to the radiation window 31 of the respective microwave radiation source 30 in the interior of the respective oven module 12 , with the aid of which a desired field optimization is made possible in the interior of the respective oven module 12 and thus in the interior of the microwave continuous oven 10 . The respective microwave steering device 52 can be designed as a two- or three-dimensional steering body 54 . A conical steering body 54 is illustrated in the figure. The shape of the steering body 54 can be designed to be changeable or adjustable. This is indicated by the two curved double arrows 56 . Here, for. B. the tip angle of the tapered steering body 54 is set. This is indicated by the thin dashed lines. Likewise, it is possible to adjust the steering body 54 in the radial direction.

FIG. 1 also illustrates bearing elements 58 which lie opposite one another in the interior of the housing 13 of the furnace module 12 . A roller 60 is rotatably mounted on the bearing elements 58 . The conveyor belt 34 of the transport device 33 lies on the rollers 60 of the microwave continuous oven 10 . The height of the rollers 60 is fixed, while the height of the respective sheet metal base 26 is adjustable, as indicated by the double arrow 29 .

Instead of rollers 60 , it is also possible to simply provide rods on which the conveyor belt 34 of the conveyor device 33 can slide.

The possibility of adjusting the distance between the conveyor belt 34 of the transport device 33 and the sheet metal base 26 results in the possibility of acting as desired on the microwaves in the interior of the housing 13 of the respective oven module 12 of the continuous microwave oven 10 in order to distribute the field to the particular circumstances to change accordingly.

Fig. 2 illustrates schematically a furnace module 12 with a circular cylindrical housing 13, to which a microwave radiation source 30 is provided. The microwave radiation source 30 is combined with a waveguide channel 62 , which extends along the circumference of the oven module 12 or its housing 13 . The microwaves generated by the microwave radiation source 30 are coupled into the waveguide channel 62 . The waveguide channel 62 serves to guide the microwave beams. The housing 13 is formed in the region of the waveguide channel 62 with cutouts 64 which form secondary radiators. The recesses 64 can be slit-shaped, cruciform or the like. Cross- shaped recesses 64 are illustrated in FIG. 2. With the aid of the recesses 64 forming secondary emitters, it is possible to achieve a desired uniform microwave field distribution in the respective oven module 12 .

The circumferential section of the housing 12 or the waveguide channel 62 , along which recesses 64 are provided, can be of variable design; for this purpose, the recesses 64 in the housing jacket 14 or in the waveguide channel 62 can be assigned a tuning device 66 , which is formed by a slide 68 can be.

In the inventive continuous microwave furnace 10, the furnace modules 12 can be arranged in a row linearly one behind the other, but it is also possible, for the furnace modules 12th B. arc or circular one behind the other in a row.

Reference list

10th

Continuous microwave oven

12th

Oven module

13

casing

14

Housing jacket

16

Front (from

12th

)

16

Ring flange (an

16

)

20th

Support organ (from

18th

)

22

Mounting holes (in

18th

)

23

Pitch circle (for

22

)

24th

Bearing elements (for

26

)

26

Sheet metal floor

28

Holes (in

26

)

29

Double arrow

30th

Microwave radiation source (an

14

)

31

Radiation window (in

14

)

33

Transport device (from

10th

)

34

Conveyor belt (from

33

)

35

Air outlet holes (in

14

)

37

Radiation source housing (for

30th

)

39

Blower (on

37

)

41

Outlet (from

37

)

43

Regulator (an

41

)

45

Air regulator (on

37

)

47

first partial flow (through

37

)

49

second partial flow (through

37

)

52

Microwave steering device

54

Steering body (from

52

)

56

curved double arrow

58

Bearing elements

60

roller

62

Waveguide channel

64

Recesses

66

Voting device

68

Slider

Claims (17)

1. continuous microwave furnace having heating zones forming furnace modules (12) which are arranged in a row one behind the other, wherein each oven module (12) comprises a housing (13) with a circular casing shell (14), wherein the respective housing jacket (14) at least one Microwave radiation source ( 30 ) is provided on an associated radiation window ( 31 ), a sheet metal base ( 26 ) being arranged in the respective housing shell ( 14 ) and being formed with holes ( 28 ) or slots forming secondary radiators, and in the continuous microwave oven ( 10 ) a transport device ( 33 ) is provided which is formed by a transport belt ( 34 ) or by transport rollers, the transport belt ( 34 ) resting on the sheet metal floors ( 26 ) of the oven modules ( 12 ) forming a common plane or in the holes ( 28 ) the sheet metal shelves ( 26 ) transport rollers are mounted which form a common plane, according to patent 197 38 882, characterized in that that the sheet metal floors ( 26 ) of the oven modules ( 12 ) are adjustable in height and / or that air outlet holes ( 35 ) are adjacent to the radiation window ( 31 ) of the respective microwave radiation source ( 30 ) in the housing jacket ( 14 ), the respective radiation source ( 30 ) is combined with an air regulating device ( 45 ), and / or that the radiation window ( 31 ) of the respective microwave radiation source ( 30 ) inside the corresponding oven module ( 12 ) is assigned a microwave steering and distribution device ( 52 ). 2. Continuous microwave oven according to claim 1, characterized in that the sheet metal floors ( 26 ) of the oven modules ( 12 ) are simultaneously height-adjustable. 3. Continuous microwave oven according to claim 1, characterized in that the sheet metal floors ( 26 ) are flat. 4. Continuous microwave oven according to claim 1, characterized in that the sheet metal bottoms ( 26 ) are convexly curved. 5. Continuous microwave oven according to claim 1, characterized in that the sheet metal bottoms ( 26 ) are concavely curved. 6. Continuous microwave oven according to claim 1, characterized in that the respective microwave radiation source ( 30 ) is provided in a radiation source housing ( 37 ) which spans and bridges the radiation window ( 31 ) and the air outlet holes ( 35 ) that on the radiation source housing ( 37 ) for cooling the microwave radiation source ( 30 ) a blower ( 39 ) is arranged and that the radiation source housing ( 37 ) for forming the air regulating device ( 45 ) has an outlet opening ( 41 ) with a regulating member ( 43 ). 7. Continuous microwave oven according to claim 6, characterized in that the regulating member ( 45 ) is designed as a sliding or rotary control member. 8. Continuous microwave oven according to Claim 1, characterized in that the microwave steering device ( 52 ) assigned to the radiation window ( 31 ) is designed as a two- or three-dimensional steering body ( 54 ). 9. Continuous microwave oven according to claim 8, characterized in that the steering body ( 54 ) is adjustable and / or adjustable. 10. Continuous microwave oven according to claim 8, characterized in that the steering body ( 54 ) consists of a highly conductive, reflective metal. 11. Continuous microwave oven according to claim 8, characterized in that the steering body ( 54 ) consists of a variable conductivity, partially absorbent ceramic material. 12. Continuous microwave oven according to claim 11, characterized in that the steering body ( 54 ) consists of SiC, ceramic-bonded SiC, of ferrite material, of microwave partially absorbing ceramic or glass. 13. Continuous microwave oven according to one of claims 1 to 12, characterized in that a waveguide channel ( 62 ) is provided on the housing shell ( 14 ) of the oven module ( 12 ), which is combined with the microwave radiation source ( 30 ), and that Housing casing ( 14 ) is formed along the waveguide channel ( 62 ) with recesses ( 64 ) forming secondary radiators. 14. Continuous microwave oven according to claim 13, characterized in that the recesses ( 64 ) extend at least along a portion of the waveguide channel ( 62 ). 15. Continuous microwave oven according to claim 13, characterized in that the recesses ( 64 ) extend along the entire length of the waveguide channel ( 62 ). 16. Continuous microwave oven according to claim 14 or 15, characterized in that the recesses ( 64 ) is associated with a tuning device ( 66 ). 17. Continuous microwave oven according to claim 16, characterized in that the tuning device ( 66 ) is formed by a slide ( 68 ).