DE2018048A1 - - Google Patents

Description

Herne, * SOOO Munich 23, Freiligrathstrasse 1 »■% ι ■ ■ η ι_ι η ι. Eisenacher Strasse 17 P.O. Box 140 D I P I. - I Π g. R. H. B a Π Γ. Pat-An ·. BcUler P «t.-Anw. Herrm «nn-tr» nttpohl IM-I ni. „. C «I ..». «J d.i.i .. Telephone: 39 80 11

Telephone: 5 10 13 DIpI.-Phyt. EdUard ΒθΙΖίβΓ S ₁₁₀₁₂

⁵ J ⁰ "Dipl.-lng. W. Herrmann-Trentepohl _τ , ^Μ8013

Telegraphic address: _-:, ι- β r · Telegrammantchrift: Bahrpatente Herne PATENTANWÄLTE Babetzpat Munich Telex OB 229 853 Telex 05 245 «2

Γ "1 bank accounts:

Bayrische Vereinsbank Munich 952287 OfI-I Ο Π /. O Dresdner Bank AQ Herne 20243t

tU IOU1Ü Pottecheckkonto Dortmund 55β ββ

1 S AFR. 1970

L J

_R .r .: H 02 202 Lew / Sz

please indicate in the answer

Please send a letter to: Oryodry Corporation, San Eamon, California, USA

Continuously operating microwave heating or cooking equipment

The invention relates to a device for heating or for cooking a material using microwave energy in particular on a microwave heating or cooking device, where the applicator or oven that picks up the material is a waveguide, as opposed to a multimode or Cavity.

In the microwave field, a "waveguide" looks at on a line, which usually has a closed cross * cut has to emit electromagnetic waves »in the microwave range« of the multiple amsmutfltsem. By expression "Rectangular" is used here to characterize a waveguide device in which two pairs eioa opposite

BATH ORIGINAL

walls (although not necessarily in the same plane or in parallel planes) that limit the waveguide on its sides. Bas symbol TE means the transverse electric field vector excited in the waveguide} 3M means the transverse magnetic field vector. If a waveguide is excited in the ΪΕ ^ mode, then (1) is essentially not electrical at all Field in the direction of the power flow (here called the z-direction) present, (2) there are m-nodes in the profile of the electrical field strength in sighting parallel to the broad walls present (here referred to as the i-direction), and (3) there are η-nodes in the profile of the electric field strength in the direction parallel to the side walls (here referred to as the y-direction).

The TE ^ Q mode in a waveguide thus relates to a state where the electric field vector extends perpendicularly between the broad walls (in the y direction) and essentially no electric field is present in the z or x directions. The explanations given above, which serve to explainea, siiaä. purely theoretical. In practice, these are only useful work tools} they can in no way be taken as unconditional definitions of structure, mode of operation or result. The free space wavelength, hereinafter referred to as "free wavelength", of the excitation frequency λ o is the length of a period of the excitation frequency as it would be if the wave were to propagate through the free tree. The b-dimension (which defines the vertical distance between opposite broad walls) can be taken to a value smaller than half the free wavelength of the excitation frequency, vm the propagation of all-testicular species and all ML ^ -mode types to "interartteken, v" m is an integer greater than zero. Furthermore, a dimension (ie the vertical spacing between parallel lines) is greater than the cold free wavelength and less than a free wavelength

BAD ORIGINA

be held _{to suppress ML n} modes / where m is greater than one. ~

In the! F & jQ mode, the intensity profile of the electric field varies to a minimum according to a pulse function τοη one side of the treatment! tone through a maximum at the transverse center of the broad wall (i.e. χ - a / 2) and back to a minimum on the opposite side of the treatment zone. So for a given input power is the electric field strength at the transverse center of the treatment zone at a maximum.

In the system of the present invention, the waveguide device couples power from a source to a waveguide applicator in a substantially rectangular cross-section having a pair opposing wide walls and a second pair of opposing side walls. The width of the wide walls (which defines the separation of the opposing side walls) is a distance a and the width is Side walls (which defines the distance between the wide walls) is a distance b. The waveguide applicator is energized by the source in the TE ^ Q mode.

The advantages of using a Vellenleiter as an appli-. Cator when heating or cooking a material are diverse, both in terms of efficiency and design. At a With a waveguide applicator, in which a traveling wave is excited and power flows through the applicator, the modes of excitation and types of propagation are more controllable.

According to the invention, the material to be heated or cooked is used conveyed by the applicator along (i.e., in or against) the direction of power flow such that the electric field vector to the largest rope perpendicular to the surface of the treated material, but can be inclined relative to this surface if the field strength decreases in order to

009851/1277 _B AD ORIGINAL

2018043

- 4 -awning process become more uniform.

One end can be in the direction of movement of the heating chamber in the form of a Water load can be provided in order to absorb all of the microwave energy not absorbed in the material to be treated. Seen from the source, there are material loads and water loads in series ι the energy not first consumed in the material load is dissipated or destroyed in the Vaeser load. this provides a gate part, as the source is thus provided with a constant load regardless of the amount of material treated.

If desired, the invention can be designed so that Air is circulated through the heating or cooking chamber) assembly for easy disassembly for purposes of inclination is also possible. Furthermore, the applicator according to the invention be provided in module types that are tandemly arranged in troughs that require greater amounts of energy.

The advantages resulting from the invention are shown in best in specific use cases {and for this purpose is a form of execution explained and described here, the particularly suitable to large quantities of ham in relative time to cook or bake. Ss should, however, on it it should be pointed out that the invention is not limited to this particular application. When packing ham the belly sides are cut into slices at high speed ι individual packs of appropriate size are separated conveyed away from the cutting area

With this system, the ham is conveyed through the heating or cooking chamber while viewing the flow of power | he will introduced through a wide wall in the inlet manifold which is so musfigured that power consumption is minimized and excitation mode types other than those avoided are called the CEι -Modearten, where m is an odd integer

009851/1277 _ß4n

is. A notch filter is close to the inlet manifold the place where the ham is introduced, coupled! the ham passes through the barrier filter. The notch filter is designed so that it prevents the leakage of microwave energy from the Place where the ham is inserted without absorbing this energy. A second notch filter is nearby provided at the point where the ham emerges from the outlet manifold.

The upper and lower wide walls of the cooking chamber are preferably inclined upwards symmetrically to the longitudinal center plane of the chamber, so that the heating chamber has a slight V-shape in cross section. The term "V-shape" as used herein, is not intended to limit the shape of the wide walls of, heating chamber to planar or straight sections, like a full understanding of the invention without further ado; the cross-section of the wide walls can rather be curved, although this would lead to additional costs in the embodiment shown. In this embodiment, the individual ham strips are placed on a flat conveyor so that the angle of incidence of the electric field vector between opposing wide wall sections is smaller at the circumference of the ham strips, where the electric field strength is smaller than in the center of the applicator. That is, the electric field lines are perpendicular to the plane of the ham at the transverse center of the treatment zone and they vary from normal to the sides of the treatment zone. The angle of incidence θ of the electric field vector, as used here, refers to the smaller of the two angles between the electric field vector and a tangent to the surface of the treated material at the point of incidence and in the course of the iy plane. With this arrangement, it has been found that a more uniform heating of the ham takes place essentially in the longitudinal direction (that is to say in a transverse view of the solder flow) in spite of the variation in the electric field strength within wide limits.

009851/1277 ^ do _R , _Qlt * L ₆ .

Lines are provided to connect air to the Heizksunmer and let it circulate through the heating chamber and thus remove moisture and gases that were generated during the cooking and heating process. A slot is also in the longitudinal center of the lower wide wall in the heating chamber Yeah. Since the curved lower wide wall forms a sense, fat produced when cooking the ham becomes useful drained by gravity flow through this slot and discharged. The entire applicator is designed to that it is excited symmetrically relative to the longitudinal center plane, so that the excitation of the 3Έ -Mode types of propagation is prevented, where m is an even number. Because the drainage slot is provided at point a / 2, there is no ΊΈ -mode-

KO

Radiation through this slot where m is an odd integer. The inlet and outlet elbows and the heating chamber are arranged in two separate sides, with central contact flanges being provided to keep them in conductive working connection. The sides can easily be linen or Wait for the inner parts of the elbow to be separated and the heating chamber for the entire applicator will be along the way longitudinal median plane separated "

According to the invention, a waveguide applicator is operated primarily in the TE ^ Q mode} treated material is used promoted by the applicator along the sighting of the power flow. Blocking filters are provided at the inlet and outlet openings through which the material is fed, to prevent the escape of microwave energy without absorption. Air is passed through the heating chamber for removal of Let moisture and gases circulate. A closure is provided downstream of the heating chamber in the form of a vase load, which absorbs all energy not absorbed in the material being treated. According to one embodiment, the broad top and bottom walls in the heating chamber are symmetrical upwards around the longitudinal center plane of the chamber inclined so that the cross section of the heating chamber is a slight

008851/1297 " ^/ "

Has V shape and the angle of incidence of the electric field vector decreases away from the center of the chamber and towards the side walls to cause more uniform heating of the material. The slight V-shape of the heating chamber forms a natural channel to guide fats, oils, etc. from the material to be heated through a slot in the bottom under the influence of the Gravity flow

An example embodiment of the invention will now be explained in more detail with reference to the accompanying drawings, in those

Fig. 1 is a perspective view of

Applicators according to the invention, which are arranged in tandem |

1A is a perspective view

V-shaped applicators according to the invention

Fig. 2 is a cross-sectional illustration

through the inlet air coupling i

Fig. 3 is a side perspective view

view of one of the applicators shown in Fig. 1A

Fig. 4 is an interior perspective view

one side of a waveguide bend and a notch filter |

_v Fig. 5 is a side perspective view

view of the inside of the left side of the applicatorai shown in Fig. 1A

Fig. 6 is a side view of the interior

009851/1277 " ⁸ "

BAO ORIGINAL

des in Pig. 5 applicator section j

Fig. 7 is a perspective view

an inlet manifold and a notch filter of an applicator from outside j

Pig. 6 is an end view of an entrance

elbow for the applicators of Fig. 1Aj

Figure 9 is a cross section through the applique

gates according to Fig. 1Aj

Figures 10-12 are schematic for understanding

serving graphs for a suggested but not essential Theory for the improved results achieved in accordance with the invention stands.

In Fig. 1 are two separate applicator sections, generally denoted by 10 and 11, respectively, and which are arranged in tandem, i. H. the material to be treated is passed through the applicator sections 10 and 11 one after the other in this order. Bas treated material is schematic at 12 it is shown continuously by means of a moving conveyor belt 13 supported. It should be pointed out It will be understood that the invention cannot be limited in its application to these types of material being treated Rather, for example, pieces of food or individual items Act food items that are arranged in appropriate dimensions. Furthermore needs for application cases heating or drying, the conveyor belt does not necessarily have to be provided in the same way as when drying endless construction

0 0 9 8 5 1/12 7 7 BAD ORiG / NAL ⁹ ~

plate strips etc.

The applicator sections 10 and 11 are excited by means of a modular microenergy source generally designated 15 via waveguides 16 and 17, respectively. In this typical application, in which quite large amounts of energy are usually required, separate magnetrons or groups of magnetrons (or other microwave power tubes) serve to feed each applicator section. The power source 15 can, for example, be able to deliver a total of 50 kilowatts of power! thus 25 kilowatts of power are coupled to each of the applicator sections 10 and 11.

Each of the individual applicator sections 10 and 11 can with regard to Construction and operation the same, (although the waveguide coupling performance on the applicator section may of course be of slightly different configuration), so that only one applicator section need be explained in more detail for a full understanding of the invention.

The applicator section 10 includes one indicated generally at 20 Elbow, a heating chamber generally designated 21 and an exhaust manifold generally designated 22. The heating chamber 21 forms the treatment zone. One himself tapered input coupling portion 23, which is in an im is substantially vertical, couples the power from the waveguide 16 to the input manifold 20. A End section 24 is connected to the outlet manifold 22; as can be seen from the drawing, the terminal section extends 24 also in an essentially 'vertical direction *

Since the tapered inlet section, the inlet manifold 20, the heating chamber 21, the outlet manifold 22 and the end portion 24 are self waveguides, a wandering wave goes through each of these sections in the order named} Power flows in a similar direction, i.e. H. of the

008851/1277 bathroom original

tapered input section 23 through the heart chamber 21 and to Final section 24 over the manifold. If in the following the expressions "in the direction of flight in front of" and "in the direction of flow behind" are used, they refer to the direction of the power flow.

Each of the applicator sections just mentioned is formed from a conductive metal such as aluminum made of symmetrical half-profiles, the inner flanges of which extend in a vertical plane for an escape to suppress the radiation or, if necessary, to hold the halves together. The entire applicator can be along a vertical plane be separated extending in the longitudinal direction of the heating chamber 21 to the interior of the applicator portion to clean. This is particularly beneficial when the system is used for cooking.

The applicator rests on horizontal cross rails of three metallic, with 26, 27 and 28 designated trestles.

An input blocking filter 29 is provided at the point in the input manifold 20 through which the is in the heating Material enters the applicator, as more precisely with reference to Pig. 4 and 7 will be described. Furthermore is an output blocking filter JO is provided at the point at which the treated material emerges from the applicator. An entry chamber 31 made of a power only weakly absorbing Material can be coupled against the entrance of the blocking filter 29, the chamber 31 and the filter 29 are from Metallboek 26 supported. The input and output filters 29 and 3ü are flanged in a similar manner to the Individual sections of the applicator attached to facilitate manufacture and convenient access against it Allow interior for cleaning purposes.

A liquid line 33 made of electrically non-conductive

0 0 9 8 5 1/12 7 7 BAD ORiGiNAL " ¹¹ "

Material passes through the inner wide wall of the end section 24, penetrates this and emerges through a head or face plate 24a of the end section and thereby forms a water load for the applicator. An inlet air line 35 is against the tapered inlet section 23 connected by means of a coupling box 36} this is explained in more detail later with reference to FIG. Sound not-shown Equipment driven air travels through the chronic entry section 23 and enters the heating chamber 21 via the input manifold 20. The application air exits through an air outlet line 38 which extends against the end section 24- is coupled by means of a second coupling box 39. openings similar to the one previously described Opening 37 are provided in the end portion 24 through the the exhaust air can enter. The air openings are small enough to hold the radiation of microwave energy for the viewed To prevent excitation frequency.

An on / off switch, generally designated 41, is provided at the entrance to the conical section 23 and comprises a metallic tongue which is able to slide through an opening in the broad wall of the waveguide 16 and this in one to complete the first position. A second or "setting of the switch 41 allows an undamped flow of power to the conical section 23. The switch 41 serves as a safety device to prevent a flow of power to the applicator when it is disassembled for purposes of cleaning, etc. In the alternative embodiment, the switch 41 can be replaced by a throttle connection, which has the advantage that it enables the applicator halves to be separated without the flanges of the conductor 16 and the conical inlet section 23 having to be unscrewed.

It is important that the material to be treated is in one place as close as possible to the floor panels 47 and 48 in the inlet manifold is introduced so that the electric field

009851/1277 *

strength vector excited in the TE ^ Q mode normal to Surface of the treated material is at the point of introduction. The orientation between material and the electrical Field strength vector is desirable to prevent excessive energy consumption at the point of entry.

The entry cut filter 29 includes three with the reference numeral 55 designated short bars with a length equal to a quarter wavelength of the waveguide and a short bar 56 matched in impedance. The short bars 55 are matched to the excitation or excitation frequency of the applicator; And you are designed so that they prevent the transmission of this frequency through the notch filter. The part 56 is one in the impedance tuned section which is also designed to match the impedance of the resonance bars 55 to that of the waveguide applicator, without excessive flexion and without Fashion styles were generated that would be able to get through to propagate the ladder.

Each of the beams 55 and the impedance matching sections 56 are rectangular shells with a lower open side of the same Extension like an opening in the upper wide wall of the input cut-off filter 29. With reference to the second embodiment ■ The blocking filters are to be discussed in more detail. It should be pointed out that the entrance and exit openings, Notch filters, power sources etc. are the same for both embodiments, their main difference is in the shape of the To see Heizkaner.

Referring now to Figure 1A, there are shown four separate applicator sections, generally designated 110, 111, 112 and 113 and arranged in a tandmike fashion and made of a metallic conductor, for example aluminum. For this particular application, useful fortions are hams Discs are arranged in a shingle-like manner in a fortion, by means of a conveyor 116 through all of the applicator

00 9 8 51/12 7 7 "bathroom original

018048

out 113 - paragraphs of the 110th The applicator sections 110 and 111 are energized by a source of micro wave energy, indicated generally at 117; the applicator sections 112 and 113 are energized or excited by a source shown generally at 118. Rectangular waveguides 119 and 119a provide coupling of the power from source 117 to applicator sections 110 and 111, respectively.

Examining the applicator section a 110 separately, it can be seen that it consists of: an input bend 120, a heating chamber (or treatment zone) 121, and an output bend 122. A conical input coupling 123 extends in a substantially vertical view and provides power from the waveguide 119 to the input manifold 120. A termination portion 124 is attached to the output manifold 122. The termination 124 also extends in a substantially vertical direction. The tapered entrance portion 123 and the termination 124 can be viewed as part of the applicator portion 110.

Each section of the applicator is in two side halves that are symmetrical about the longitudinal median plane (i.e., which extends in the sighting of the power flow) are divided} and each complementary half section is with a Flanged to hold the halves in place. In practice, these flanges do not necessarily need one to establish continuous conductive contact, since itself when there is a slight separation, no noticeable portion of the radiation can escape.

A conduit 125 runs vertically through the terminating section 124 of the applicator in three separate turns according to the illustrated embodiment, although more or less turns or passages can be used. Water from a source not shown is supplied through line 125 pumped and provides a load that any, the final

009351/1 VII

Section 124 attaining power absorbed. It should be noted that the applicator 110 is a waveguide and that it is designed so that most of the energy is in the TE ^ mode. Power flows from the source 117 through the waveguide 119, the tapered entry section 123, the elbow 120, the heating stacks 121 and the exit elbow 122 into the termination section 124, in that order. Furthermore, the termination section 124 is an actual section, since very little power is reflected back into the heating chamber 121 after it has been fed into the termination section 124 once. Thus, the water load carried by conduit 125 - it may be a thin dielectric tube - absorbs substantially all of the unused power in heating chamber 121. The combination of a waveguide applicator and an enclosure in which the product passes through the applicator allows the system to operate with little or no power shift from the source, although the amount of material treated can vary considerably. Seen from the Hagnetron, the load remains stable and its operating frequency is relatively independent of fluctuations in the amount of material treated. In addition, the waveguide applicator forming the heating chamber or treatment zone, as well as the terminating section, can be oversized. That is, the effective distance between the side walls along a line running transversely to the wide walls, which is equidistant from them, can be greater than one wavelength of the excitation frequency and the output heating rate and reduce the attenuation constant.

A secondary air filter, generally designated 126 and described in more detail here, is connected to the inlet duct 120 and the conveyor 116 with chinksiipox ¹ bionen 115 moves through the inlet opening filiiei ¹ 126 and the inlet bend 120 into the heating chamber or treatment zone 121. An outlet aeration filter 127 is also aa the place on the outlet manifold 122

009851/1277 " ¹⁵ ~

see at which the ham emerges from the applicator section 110 and transfers to the adjacent applicator section 111 will.

An inlet air line 128 is against one side of the conical Inlet section 123 is coupled by means of a coupling box 129 and at this point there are a large number of openings 138 (see Figures 2 and 5) in the conical entry section 123 designed to enable the forced flow of air. The air is passed through a similar junction box 130 is discharged and the exit air line 131 is connected to the terminating section 124, which is provided in a similar manner with a number of openings. The size of the openings allows the passage of air, but is small enough to to prevent the radiation of energy for the excitation frequency (approximately 1/4 - 1/2 inch diameter, corresponds to 0.64-1.28 cm).

The on / off switch, generally designated by the reference numeral 132, is at the interface between the waveguide 119 and the conical entry section 123 is provided to selectively either the flow of power into the applicator section 110 to prevent or allow microwave energy to be transmitted to the applicator section without attenuation. Alternatively, the on / off switch 132 can be replaced by an inductive pole coupling, with the advantage that the separation of the -Applikaterseitenhälf th is possible without the flanges of the input waveguide 119 and the conical Entry section 123 would have to be unscrewed.

Xn Fig. 2 now the inlet air coupling is shown in more detail. The exhaust air clutch design is similar. As can be seen, the tapered entry portion includes 123 first and second wide walls 134 and 135 and first and second calibrated opposite side walls 136 and 137 (in Fig. 1A can be seen). This construction allows that

009851/1277 -16-

018048

the applicator can be separated into two side parts for cleaning purposes. The left side of the conical section 123 is provided with the wide walls 134 and 135 and the side wall 136 with the openings 138. The junction box 129 closes all of the openings 138 in a sealed manner, so that air is pressed through the inlet line 128 into the coupling box 129 and enters the conical inlet section 123 via the openings 138. The openings 138 can be designed so that the area surrounded by the junction box 129 is 50 % permeable. Also, as shown in Fig. 2, a thin dielectric membrane 139 is fitted into the rectangular waveguide 119 above the air pressure point 138 to allow the air to be directed to the source 117 while allowing the undamped power flow through the waveguide.

As shown in Figure 2, the switch 132 is selectively moveable in and out of position and in the location where it is installed is, there is a slot 119b which is provided in one of the wide walls of the waveguide 119. A tongue 132a fits into slot 119b and is selectively moveable to a first position in which the strap of the tongue rests on a wide wall is aligned; and movable to a second position in which the tongue extends across the width of the waveguide and serves as a seal to prevent power from flowing through. This is a security measure to reduce hazards while the system is being cleaned or otherwise disassembled.

According to FIG. 5, there is now one half of the conical entry section 123 is shown in more detail and comprises essentially one vertical flange 13 ^ a, coming off the left side of the Wide wall 134 · protrudes and a flange 135a, which is perpendicular protrudes from the left half section of the wide wall 135.

Located at the base of the conical entry section 123

009851/1277 - 17 -

the bend 120 which couples the power from the conical inlet section 125 to the part of the applicator section 110, which forms the heating chamber. The inlet manifold 120 is divided into left and right halves by means of central flanges just like the conical sections, exit elbow, heating chamber 121 and end section 124 held together will. Seen again in the power flow direction, the left half of the applicator section 121 of the horizontal cross rails of a pair of metal brackets 141 and 142 are supported and fixed against them. Like me becomes the left half of the inlet filter section. 126 mounted on a metal bracket 143. As FIG. 5 shows, the left half side of the inlet manifold 120 is attached to a cross rail 141a of the bearing block 141 fastened by means of screw and nut assemblies 146. The other hand is the right section of the applicator is movably supported by the cross rails 141a and 142a to separate the two sections of the applicator for the sake of cleaning!

5 and 6, the inlet manifold portion is 120 provided with an upper surface 120a, against which the knoic entry section 123 is releasably secured by means of bolts 148. The input elbow 120 forms a smoothly curved transition for the wide walls of the conical entry section 123 from an essentially vertical position into the essentially horizontal position of the heating chamber, while the conduction of the TEuq mode excitation type is continued. A floor panel 150 is formed integrally with the input manifold 120 and extends extends outward in a horizontal direction through the inlet manifold and partially forms an opening 151j through it the ham 115 and the conveyor belt 116 into the heating chamber enter.

152

A splash around the opening I5I / forms a place to which the input filter section 126 can be attached. Fig. 6 shows that the arrangement of the belt 116 is essentially

- 18 -

009851/1277

runs horizontally, while it penetrates the entire treatment zone in the longitudinal direction; and the ham or that to be treated Product is transported to the inlet manifold 120 at a location very close to its bottom plate 150. It has found this to be of considerable value in preventing excessive energy dissipation at the site should where the product enters; also has the smooth, symmetrical The training and deformation of the inlet manifold 120 has been found to be advantageous in order to avoid excessive excitation to prevent undesirable fashions, d. H. (DE fashion types where m is greater than one.

According to FIGS. 5, 6 and 9, the heating chamber 121 is also divided into left and right sections along a through the middle of the wide walls subdivided running plane. The left half or the left section can be seen in FIGS. 5 and 6; the right one Section is the mirror image of the left section. The heating chamber 121 is elongated in the horizontal direction and its wide walls (in the sense defined above) generate an electric field, which is on a vertical plane perpendicular to the horizontal Power flow is limited.

The left section includes upper and lower parallel walls 153 or 154 ·· The upper wall of the left section 121a is provided with a vertical flange 155 which is against a corresponding flange 156 on the top wall 157 of the right Element 121b of the heating chamber (Fig. 9) engages. The upper and lower walls 153 and 154 are, as can be seen from Fig. 9, parallel to one another, although in general the invention need not be so limited. That is, the walls 153 and 154 can, as shown, in a cross-section to the direction of the power flow be curved. These walls are at their remote end by means of a vertical side wall 158 tied together. Similarly, a lower wall 159 is on the right side 121b formed parallel to the top wall 157; a right side wall 160 extends perpendicularly

009851/1277 - 19 -

between upper and lower walls 157 and 159

The upper walls 153 and 154- are inclined so that they one Make an angle of 20 ° to a horizontal plane passing through its line of intersection. Since the lower walls 154 · and each run parallel to the upper walls 153 and 157, the lower walls also form an angle of approximately 140 ° relative to one another. The lower wall 154 is provided with an in a flange lying on a vertical plane 161} the lower right wall 159 is provided with a similar flange fitted. The flanges 161 and 162, however, do not engage one another, but rather are separate from one another and form a slot 163 ″ through which fat emerging from the ham during the cooking process can run off.

The slope of the lower walls 154 and 159 forms one Channel through which the leaked fat expediently drain and may collect at slot 163} however, as will be discussed below, this is not the primary function to act on make the walls 154 and 159 in this way.

Particular reference is made to FIG. 6 and the interface between the input manifold 120 and the heating chamber 121, the end of the heating chamber 121, which is connected to the downstream end of the input manifold 120, is modified, in order to adapt the contour of the bend to that of the slight V-shape of the main part of the heating chamber 121. According to FIGS. 5 and 6 stands the base plate 150 of the inlet debris 120 with a inclined plate 168 in connection, which (as can be seen in Fig. 6) is perpendicular to the plane of the drawing. The plate 168 has rectangular shape; a second plate 169 connects the forward or upstream end of the bottom wall the left half 121a of the heating chamber with the plate 168 forming a continuous floor for this side of the Heating chamber.

009 851/1277 -20-

It should be noted that the overlap between the panels 168 and 169 forms a corner drain or channel leading directly to the front edge of the slot 163 Purposes of the process. The other four lower corners of the heating chamber are similar with respect to the interface modified with the bends. So the bottom of the heating chamber is inclined in such a way that the entire area of liquid is underneath drained under the influence of gravity.

A full flange interface is between the elbow 120 and the heating chamber 121, as can be seen at I70 in FIG. 6, Ρ is provided.

The inclined side wall 158 of the heating chamber 121 is also shown in FIG modified the interface with respect to the vertical side wall of the inlet manifold. This comprises a single plate with a lower portion I7I (see Fig. 6) which is integral with the outer edge of the base plate 169 and the downstream edge of the side wall of the inlet manifold 120 is and has an inclined portion 172 integral with the plate 171 and the side wall 158 of the central portion of the Heating chamber 121 open. Sections I7I and 172 can consist of a common panel by bending along fold line 173 ^ are formedj this is in Fig. 3 even clearer for the corresponding facing plate, indicated generally by the reference numeral 175, and an upper one Has part 175a, which is in a plane of the inclined side wall 160 of the heating chamber and has an upper part 175a, which lies in the plane of the inclined side wall plate 160 of the heating chamber and has a substantially vertical part 175b, which forms a continuation of the vertical side wall 120c of the entrance debris 120.

Looking at the downstream section of the Heating chamber 121, which makes the transition to the outlet manifold 122, so this part of the heating chamber has - as in Fig. 6

0098 5 1/1277

See - the elements that correspond to each of the elements just described with respect to the interface or intersection between the heating chamber and the input manifold 120. The output bend 122 has a base plate 178 over which the conveyor belt 116 runs} an inclined drain is also formed by the blades 181 and 182, which leads to the downstream end of the slot 163. As already mentioned, the right-hand sections of the inlet and outlet bends, like the fireplace stove, are symmetrical with respect to the left half-element relative to a vertical plane running through the center.

The input rejection filter 126 is also formed in the form of two separable halves, a right half 126a, as from FIG the inside of Fig. 4 can be seen from, and a left half 126b, as seen in FIG. Again, the right half of the input rejection filter is the mirror image of the left half of it ! Filters; and only the left half that is in Pig. 7 shown therefore needs to be fully described to give an understanding of this part of the system. Like from Pig. 4 shows the right half of the notch filter with a Bottom plate 184 is provided, which forms the continuation of the bottom 178 of the right half of the inlet manifold 122. The left Half 126b of the input notch filter is similar provided with a base plate 185, which is a port setting of the base plate 150 of the left half side of the inlet manifold forms.

The input blocking filter comprises three blocking sections, each designated by 186, formed in the upper wide wall and these sections are designed in such a way that they completely block the frequency which excites the waveguide applicator. A separate pilter section 187 is interposed between the blocking sections 186 and the input manifold 122 in order to bring about an adaptation to the connection at the input manifold and thereby ^{reduce reflections to an N -} J ti 1 * ^ ™.

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009851/1277 BAD ORIGINAL

-22- 201 8 OA Ο

Me combined transverse length of each of the barrier short beams 186 (the is the dimension transverse to the direction of movement of the ham) is smaller than half the wavelength of the excitation frequency. the three pilter sections 186 are periodic in nature} and the period of the short bars (that is in the direction of movement of the ham) is equal to half the waveguide wavelength. The height and width of each of the short bars 186 is equal to a quarter wavelength of the waveguide. When matching the impedances by means of a matching section 187, the height of the section 187 and its displacement from where the ham enters the entry manifold 120 is set to reduce the reflections occurring at the source to a minimum. This is best done empirically; and hangs on the wavelength of the waveguide, the excitation frequency and the input impedance of the notch filter 126. Similar Interpretation considerations can be made with regard to the notch filter; it should be noted that each waveguide applicator section has both an input notch filter and an output notch filter.

It has been pointed out that notch filter short bars in the upper wide walls of the input and output filter sections can be used. This has two advantages. First, this avoids that leaked liquid in shell-like short bar flows off. Second, the electric field vector is forced into a position normal to the product, and because of the flat bottom wall 185 and the proximity of the product to the wall.

With regard to the final section 124- it should be said, that this too is again designed with symmetrical right and left sides, which by means of adjoining smock flanges be held together. The aforesaid conduit or hose 125 for carrying the water load extends inside of the waveguide section and absorbs energy that was not absorbed by the ham.

BATH ORIGINAL 00985 1/1277 ~ ²³ "

Before the particular advantages of the illustrated invention Embodiment to be discussed should be a certain. theoretical basis to be given in order to understand the working method to give the system according to the invention as a whole.

In a rectangular waveguide construction, the width a of the broad wall can be restricted to less than the free wavelength of the excitation frequency and the width of the side wall to less than or equal to 1/2 a in order to suppress _{modes other than the TE ^ Q mode.} The dimension a can be made larger with certain advantages provided that the reduction in dimension b is maintained and care is taken of the manner in which the waveguide is excited. Such an oversized waveguide with a rectangular cross-section, which is excited or excited in the IE ^ Q mode, has an electrical peId with only one vertical (or y-direction) component which is constant; and the electric field strength varies in the x-direction according to a sinusoidal change, the electrical field strength being zero on the side walls and at most in the center plane of the waveguide in the direction of the power flow. If the waveguide is oversized, then the terminating section carrying the water load will preferably also be oversized in order to prevent the accumulation of excessive amounts of reactive energy in the heating chamber of the applicator, as described in the related application of the same day (internal file number M 02 201) explained.

Although the waveguide applicator according to the illustrated embodiment has a heating chamber that is not really rectangular in cross-section, because the electric field strength vector is there substantially perpendicular between the upper and lower walls 153 and 154 and the parallel upper ones and lower walls 157 and 159 (Pig. 9). In this sense the walls 153 and I57 form an upper "wide wall" and the walls "15 ^ and 159 form a lower" wide wall ".

nftlGlNAL INSPECTED 0 09851/1277 0 ^sheet

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It also measures the amplitude of the electric field strength vector equals zero on sidewall 158, increases to a maximum in the vertical median plane, and then decreases to zero on the side wall 160, although the exact fluctuation is not actually a sinusoidal wave as in the case of a waveguide needs to be rectangular cross-section. The electric field strength does not vary over the length of one of the ham slices (that is in the x-direction). It has been found, however, that the fact that the waveguide is formed as in the illustrated embodiment, after which the upper and lower halves of the broad walls are inclined about the central plane and without the orientation of the ham slices too change, the cooking of the ham is essentially more uniform through and through than that of an actually rectangular one Waveguides of the same width can be expected.

While it is not intended to limit the inventive concept in any way to the correctness and completeness of any theoretical explanation for this observed result, an explanation is to be given which is believed to represent more uniform consumption or depletion of power. In addition to the sine-square effect discussed above, which defines the power fluctuation that is dissipated or annihilated in the x-direction in a rectangular waveguide, that is due to a thin product (that is, thin with respect to the wavelength of the applied electric field with a run of, for example, 1/10 of the wavelength ^ exnff jrunction ^{8 or 5} orientation of its surface to the electric field vector.Maximum coupling of the microwave energy is brought about when the larger dimension (that is the surface of the material) is parallel to the electric field vector In other words, the "thin" dimension is in the x-direction, and minimal coupling occurs when the surface of the material is perpendicular to the electric field vector.

ORIGINAL INSPcCTED

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For a thin material, the coupling of the microwave power fluctuates into the material given by a waveguide excited in the QJE ^ Q mode mode, from a maximum coupling when the thin material extends in a plane parallel to the electric field vector up to a Minimum if the material is in a plane perpendicular to the electric field vector.

For orientations of the material in any other direction, the situation can be as illustrated in FIG. 12, where the material is denoted by the reference numeral 192 and the electric field vector is denoted by an arrow 193 which is in a vertical sighting. It should be noted that the arrow has an angle of incidence relative to material 192 that is perpendicular to a tangent to the material at the point of incidence. Thus the coupling power going into the material 192 is at a minimum at this point. Conversely, * forms to the right edge of the material 192, which is inclined downward, the electric field strength ^{vector E 1} , which is represented by the arrow 194-, an angle Θ which is less than 90 °. The vector E ¹ can be divided into a normal component E ^ and a parallel component EJ>. In this case, the total power transmitted into the material 192 is equal to the sum of the power consumed by the electric field vectors EJ1 and ΕΛ. If one compares these two examples, although the electric field strength is greater at the point of the vector 195 than at the point of the vector 194, the overall coupling can be more balanced because of the reduced angle of incidence (which induces a parallel coupling component). As already indicated with reference to an "angle of incidence ¹¹ ", it should be pointed out that there are always two such angles in any plane, and as used here the term refers to the smallest of these two angles.

According to FIG. 11, the sides of the heating chamber 121 of the illustrated

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009851/1277 ORIGINAL IM

Represented embodiment of the waveguide forming is indicated schematically by the circumferential line 195} the electrical field strength lines are indicated by parallel dashed lines 197. Of course, the electric field lines 197 are only idealized representations of the actual field vector and their orientation changes their direction with the excitation frequency. The orientation of a single slice of ham is indicated in cross section by 198 and the supporting surface (in which it can be the previously described conveyor belt) is denoted by the reference number 199. From Fig. 11 follows further that, during the angle of incidence of the electric field strength vector in the middle of the ham slice 198 is 90 °, the angle of incidence θ at the outer limits is somewhat smaller than 90 °. According to a preferred embodiment, this angle is equal to 70 °. The idealized representation according to FIG. 11 is only an approximation of a continuous fluctuation of the angle of incidence Θ, but one that still eliminates the coupling between the point at which the electric field strength has maximum intensity to a point on the band of the treated Material can fluctuate where the electric field strength is reduced.

An alternative for achieving similar results is shown in FIG. 10, where the dashed line 200 represents the previous represents the aforementioned sine-squared energy consumption curve; and the line 201 shows schematically the rectangular cross section of a waveguide. According to this example, the electric field vectors 202 everywhere perpendicular to the planar wide wall} and the supporting surface 203 for the to be treated Material 204 is curved. Again the angle θ decreases from the point at which the electric field strength is at a maximum is located towards the peripheral edges of the material being treated, where the strength or intensity is reduced.

As already mentioned, the idealized diagrams in FIGS. 10 and 11 only represent approximations in the sense that the

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angle of incidence θ does not continuously decrease if one goes from the middle to the side walls. However, the effect described here can be combined with the related patent application from the same day (internal File number H 02 201 of the applicant), which describes the design of an upper-size waveguide applicator in order to achieve a more uniform heat consumption, if desired.

The angle φ can be between the horizontal and the wide-screen parts of the V-shaped, in Pig. 11 illustrated waveguide for the processing of ham it is about 20 °. It should be noted that this is not the only angle can be changed in order to achieve different results, the angle can rather also vary in the z-direction of the heating chamber, so that, for example, the angle f can be 15 ° towards the power inlet end} on in the direction of flow

towards the downstream end, the angle f can be 25 °, to control the heating on the peripheral edges of the treated material as a function of ζ. As mentioned, is the term "V-shaped" is not to be interpreted in a limiting manner, nor is it intended to be given a meaning that the inclined edges of the wide walls are necessarily straight because of the heating or coupling rate under certain circumstances To regulate, it may be necessary to curve these walls and continuously decrease the angle of incidence while the electric field strength decreases.

The perpendicular distance between opposing side walls (see b in Fig. 9) is kept to less than half the wavelength of the excitation frequency, so that even when the TE ^ mode types (where η is an integer greater than zero) are excited , they do not reproduce. The TE _mo modes, where m is an odd integer, do not radiate through the slot 163 because they are symmetrical about the central position of the slot. The TE fashion types, where m a straight

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are not excited because of the symmetrical excitation of the waveguide applicator.

The invention enables a waveguide applicator to be used when heating or cooking material. This prevents significant benefits in a number of areas, where The most important is to be seen in the fact that the adaptation to impedances is possible, the propagation of certain types of energy through the waveguide is ensured and (in combination with the water load) the load at the source is stabilized, although the amount of the treated material varies V « Tin. Furthermore, the waveguide design enables and the limited opening size the use and design of barrier filters in places where the material to be treated is introduced and carried out without the ineffective Wasaerlas th, which were necessary in known systems, provided will MUST.

Another part of the gate is that when using a waveguide cooker applicator, the itorikrmung over the width the product (that is in x-direction) between and in Inspection of the longitudinal struc- ture of the wide walls is carried out, is made uniform by decreasing the angle of incidence of the electric Jeld vector, while the electric field strength itself decreases.

Another advantage of the invention is that the load can be varied without the risk of excessive radiation to the atmosphere or excessive reflection represents energy or excessive build-up of an electric field, since the Waaserlast is a real closure and the whole Energy not previously absorbed by the treated material with little reflection absorbed. This simplifies the safety requirements and the monitoring of the applicator in of interpretation. . ,

009851/1277 - 29 -

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The invention has now been completed using a single duct described with regard to a brief position in the coffin} Inderungen and modifications are within the scope of the invention.

009851/1277

Patent claims *

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Claims (1)

Claims Gate direction for the transmission of microwave energy to rialien, characterized by waveguide formations with first and second, spaced apart wide walls opposite one another} excitation devices with a source for Microwave energy coupled to and energizing the waveguide means to create an electric field of varying strength which extends between the first and second wide wall means extends} carrier means for supporting this material between these wide walls and means for moving this material between these first and second wide walls and along the direction of power flow through this waveguide, these Waveguide device and this carrier device cooperate to increase the angle of incidence of this electric field to change this material as the intensity of the electric field varies. 2. Door direction according to claim 1, characterized in that this carrier device essentially consists of this material flat arrangement and that at least one of these first and second wide screen devices a relative to the order of this material in a direction transverse to the movement direction of the material forms inclined surface. 3 · Door direction according to claim 2, characterized in that said waveguide means comprises a waveguide heating chamber formed on a first pair of opposing sides by said first and second wide screen means and smf through a second pair of opposite sides first and second crosswind · each of which is between these first and second wide-wall devices is coupled and that the excitation device this waveguide heating chamber stimulated or excited essentially entirely in the TE ^ Q mode. 009851/1277 - 31 - 4. Apparatus according to claim 3t, characterized in that the waveguide heating chamber is elongated in an essentially horizontal plane and each of these first and second wide-screen devices symmetrically us its lings running center is inclined to form a V-Ge et old,. such that the angle of incidence of the electric field lines between these wide-screen devices with decreasing strength this electrical suffering is decreasing 5. Apparatus according to claim 4, characterized in that the lower T-shaped wide wall of this heating chamber has a lower one Has point at its transverse center and a slot running in the middle of the power flow direction forms in such a way that liquids escaping from this material during the transmission of microwave energy thereon as a result of gravity, the lower wide wall lings against this Slot to expire. 6. Apparatus according to claim 1, characterized by termination devices which are connected to these Vellenleitereinrichtungen Stromungsabwirts in sighting the flow of power from a Point at which the material moves between these first and second wide winches, is coupled in such a way that the Termination device of this material non-absorbed «power absorbed w ± * 4 to reflected power on a Lower the minimum. 7. The device according to claim 1, characterized in that said waveguide device has input shaft funrion devices for receiving power from this source and has a waveguide entry elbow which has these Outputs power in a substantially horizontal direction} that the Vellenleiterheizkammer receives power from this input waveguide device and upper and lower opposite wide walls that each form a V-angle in cross-section, with the center in each case the 009851/1277 BATH ORIGINAL • ΐ _t '■> lower point represents · divides | and that »in · output waveguide device receives power from · this heating chamber and has linear directions in order to absorb the · ·· power in the end · 8. Device according to laapruch 7 »characterized in that dl · ·· under · wide wall of the heating chamber an elongated, through their. Center in the direction of the performance flow ßchlit »forms. 9 · .Torrichtung sum lechan or Backan of separate batches • the portions of "chinkanechaiben, webai the" cheiban every Oharfa echindal-like ttbarainandarg "l" ft, gakennseichnet by a Vallenleiterapplikator, which forms a · Heiekajuier old upper and lower broad, see opposite) which run in a horizontal horizontal direction, with each length side of each side wall inclined upwards and the longitudinal center line with a tial ajü. ren portions of the aea ham · bear where aie in la weeentliohen. horieontaler arrangement duroh the Hei »chamber SWI • take dieeem Ireitwtnden lead, with jode single disc t 'he do this is lreitwtnden and% iellenmuebildungen rorgeaehen mimes" ma dieeen Ipplikator essentially Röllig aniuregen ^ ₀ -Hedeart in the B or eu excite · * 10. Apparatus according to claim 9, characterized in that this applicator has further hanging devices, what power ems from this source take up in order to give the power to this Vellenleiterheizkammer iu, the inlet manifold this power in a substantially rertikal Eichtung receives and transmits them in a la substantial horizontal sighting to the Helskamaer and forms an opening to a To allow implementation of the ham to the lammer. 11. Continuing to process a material with essentially would run more uniformly in one direction, characterized, that microwave energy through a waveguide in a longitudinal 009 85T / T277 201804a - 53- direction of calibrated opposite broad winds is released, this Articles flee the wide winds in the direction of their longitudinal extension, while the electrical power lines are set and their angle of impact on the Surface of this article fluctuates in a plane perpendicular to this longitudinal direction and a uniform · heating of this Article induced along this one direction. 12. Device for transmitting microwave energy to a Material characterized by waveguide devices with wall formations which extend in a first direction and have a closed cross-section for spreading an electric field in said first direction, the electric! field vector lies in a plane normal to this first direction} excitation devices with a source for Microwave energy which is coupled to this waveguide device in order to excite it and thereby the electrical Part to supply} and means for moving this material within this wall formation along this first direction 13 · Door direction according to claim 12, characterized in that this waveguide device with a waveguide heating chamber first and second, facing wide walls at a distance from one another, between which the electrical field vector stands. 14. Apparatus according to claim 13, characterized in that the waveguide heating chamber is substantially τοη a rectangle cross-section and has first and second wide-wall formations around a first pair of opposing sides and to form a second pair of opposing sides with first and second wide-screen devices, and that this exciter device excites or excites this waveguide heating chamber in the TE ^ -Hodearten · 15 · Device according to claim 14, characterized in that - 34 - 00 9851/1277 BADORiGlNAL this Vellenleiterheizkammer lent en horizontal direction is in a ent in we · elongated and said first and second wide wall means half the Ireiraumwellenlänge the Anregungefrequenz are also arranged at a distance less than, such that the propagation of the EE ₁₁₁₁ - blocked and ÜS ^ -Hodearten where η is greater than zero. 16. Gate direction according to claim 12, characterized in that this waveguide device is a pair of opposing Has wide walls to form a heating chamber and output shaft devices are also interposed between this Vellenleiterheiz- ™ chamber and this closing device, to deliver power therebetween, the output waveguide means further forming an exit opening to to lead this material out of this heating chamber} and blocking filter devices associated with the output waveguide devices are coupled to prevent the escape of sound microwave energy through this opening. BATH ORIGINAL 009851/1277