DE102006037815A1 - Transport device for a microwave treatment plant - Google Patents

Abstract

It is claimed a transport device for a microwave treatment plant with an endlessly circulating support belt (1) for transporting the material to be treated (2) in a substantially horizontal transport direction (8), wherein above the fastener tape (1) at least one on the material to be treated (2) effective hold-down element (3) is arranged from microwaveable material.

Description

The The invention relates to a transport device for a microwave treatment plant, which continuously transports a material to be treated through the system.

A Microwave treatment with continuous throughput can be at various medical supplies Find application. For example, in the sintering of ceramic products, in Harden of products of epoxy resin or other multi-component products, when cooking and drying food or when drying other goods.

For example, describes the DE 10 2004 056 795 A1 a multi-level microwave continuous dryer for plate-shaped products, in which a conveyor belt and means for moist air extraction as reflection screens for the microwave radiation are effective, so as to achieve an optimal drying process.

In practice has now been found that in particular thin, plate-shaped material to be treated, lying on a conveyor belt through a treatment plant guided is, from a certain transport speed or at a unfavorable inflow by one for the convection drying used airflow to lift off the conveyor belt tends. As a result, the material to be treated by Collisions with components of the system damaged.

Furthermore There may be wedging of these products between the internals within come to the microwave treatment plant, causing a blocking of the Plant, resulting in a loss of production.

To prevent these disadvantages is at one of the DE 35 27 645 C1 Known convection and contact dryer in addition to the transport or fastener tape provided a shroud of metal fabric, the material to be treated is guided between the fastener tape and the shroud. However, such a shroud can be used only with a strong loss of power in a microwave treatment plant, because the metallic shroud reflects the microwave radiation such that the desired penetration of the microwave radiation is substantially reduced in the treated.

Of the Invention is therefore the object of a transport device for one Microwave treatment plant to create a reliable transport of the material to be treated even at high throughput speeds guaranteed is, as well as a microwave treatment plant for continuous Continuous handling of goods with high power output and with a named transport device to accomplish.

These The object is achieved by a transport device with the features according to claim 1 and by a microwave treatment plant according to claims 7 and 9 solved. Appropriate further education are in the respective dependent claims Are defined.

According to the invention is this a transport device with an endlessly revolving strap for Transport of the material to be treated in a substantially horizontal Transport direction and at least one at least partially made of microwaveable Material existing hold-down provided, which above of the fastener tape is arranged.

When Microwaveable is here a material with a high transmittance in terms of Microwaves understood, i. almost the entire on the hold-down element impinging microwaves penetrate the material of the hold-down element without to be reflected and without being absorbed by the material, so that the hold-down element by the microwaves is not essential heated becomes. In other words, materials which are suitable are suitable have low dielectric loss factor.

Of the Advantage of this design is a high power output of microwave radiation in safe Transport of the material to be treated through the system. In experiments became an up to 75% higher power yield achieved as in microwave treatment plants with a metallic Down member.

One partially made of microwaveable material existing hold-down element is executed that the microwave radiation is almost without interference acts on the material to be treated by the hold-down element. For example cover possible metallic components of a hold-down element only insignificant surfaces of the treated material, so also a high power output the microwave radiation and a sufficient microwave irradiation for the respective treatment is achieved.

According to one preferred embodiment According to the invention, the hold-down element consists of polytetrafluoroethylene (PTFE), polyethylene (PE), perfuoralkoxy copolymer (PFA) or off Fluorinated ethylene propylene (FEP).

According to a further preferred embodiment, the hold-down element consists of an end los rotating flat screen belt, wherein the leading strand of the wire is arranged in a parallel plane of the fastener tape such that it presses and fixes the material to be treated on the fastener tape. For this purpose, the transport direction of the wire belt is arranged substantially parallel to the advance direction of the fastener tape.

The Sieve band can with respect his position opposite the lanyard and re the pressure applied to the material to be treated adjustable. This allows the screen belt advantageously different dimensions and properties of the material to be treated. Also a while the drying process along the conveyor line shrinking treatment can so optimally from the beginning to the end of the conveyor line and safely guided become. Such an adjustment For example, by vertically adjustable deflection and support rollers the screen belt can be realized.

As well Like the hold-down screen belt, the strap can also be adjusted accomplished be so as to the interaction between tape, drying material and hold-down element to optimize.

A further preferred embodiment provides that the hold down element is essentially parallel arranged, endlessly circulating narrow bands or ropes. The bands or Ropes also consist of a microwaveable plastic.

such Narrow hold-down elements have the advantage that they have a for Convection drying necessary air flow from and to the surface of the Handicraft less hinder than a nationwide screen belt. Thereby The performance of the system is further improved.

Especially in band or plate-shaped treatment goods is this version advantageous applicable by, for example, the bands or Ropes are arranged only in the edge regions of the material to be treated. It can already be enough above the lanyard a narrow band or a rope in the edge area to arrange the material to be treated, for the safe transport of flat material to ensure. As a result, the material and the production costs for the hold-down element significantly reduced and an airflow may, for example, for the purpose the convection drying almost unhindered on the treated be directed.

One Another aspect of the invention relates to the rotational speed of the fastener tape and the hold-down element. This is preferred Carrier tape and the hold-down elements with the same rotational speed operated. This can be achieved either by controlled drives which are over a control device at least in terms of their rotational speed be synchronized or only one of the two elements is driven and the other is over taken the drying material.

Especially This feature is important for products with sensitive surfaces. The same rotational speed of the fastener tape and the hold-down element guaranteed then that the surface of the material to be treated not by friction between the material to be treated and hold down element damaged becomes.

The The present invention further includes a microwave treatment facility with a transport device according to the invention and with several arranged in the transport direction one behind the other Treatment chambers. In the individual treatment chambers can each separate treatment steps, such as heating, convection drying, Microwave drying can be applied or it will be several treatment steps applied simultaneously. So can in a continuous dryer in the first drying chambers e.g. only a heating by means of microwave energy take place and in subsequent chambers additionally an air circulation system be provided for convection drying. In other drying chambers can subsequently without any heating device only moist air be removed from the environment of the material to be treated.

Corresponding can the hold-down element according to the invention on the entire conveyor length of the Lanyard or the plant extend or arranged only in partial areas so that, for example, only in areas where air streams for convection drying occur a hold-down element is arranged. That means that Hold-down element also consists of several separately mounted and driven Parts can exist.

Finally includes the present invention also microwave treatment plants in Mehretagenbauweise, wherein at least in one floor a lanyard with a hold-down element according to the invention is provided.

Further Advantages, features and applications of the present Invention are based on an embodiment and the accompanying drawings explained in more detail.

The FIG. 1 shows the schematic representation of a transport device according to the invention in the side view.

This is a material to be treated 2 on a lanyard 1 in a transport direction 10 transported. By a hold-down element 3 becomes the item to be treated 2 on the tape 1 pressed and held.

The below the material to be treated 2 arranged lanyard 1 is an endlessly circulating belt, which at the inlet and at the outlet of the transport device by a respective deflection roller 7 is diverted. It is also possible between inlet and outlet of the transport additionally one or more guide rollers to be arranged, which support the tape in the forward and reverse and lead. The guide rollers could be arranged for this purpose also below the return strand. Direction arrows 9 show the direction of the lanyard 1 at. The pulley 7 at the outlet is by the engine 11 driven and drives so the lanyard 1 at.

Above the material to be treated 2 is the hold-down element 3 also arranged in the form of an endless circulating belt. It is about leadership roles 6 guided and deflected such that between supply and return strand of the tape microwave antenna antennas 4 and wet air exhaust 5 can be arranged. The hold-down element 3 So it's about the microwave rod antennas 4 and the moisturizer 5 guided around. In this way runs between the microwave rod antennas 4 and the material to be treated 2 , as well as between humid air exhaust 5 and items to be treated 2 only one strand of the hold-down element 3 ie the interaction between microwave bar antennas 4 and the material to be treated 2 , as well as between humid air exhaust 5 and items to be treated 2 is only slightly affected. The directional arrows 10 show the direction of the hold-down element 3 at.

According to the directions of the lanyard 1 and hold-down element 3 If the transport direction of the material to be treated results 2 , which by the transport direction arrow 8th is displayed.

In addition to the guide rollers shown in the figure 6 it is possible to provide further guide rollers or rollers, for example, the flow line of the hold-down element 3 on the material to be treated 2 to press.

The moist air extraction means 5 are designed as suction nozzle boxes and provided on the bottom with an opening, which is advantageous over the entire width of the material to be treated 2 extends. Also the microwave bar antennas 4 preferably extend at least over the width of the material to be treated 2 ,

The hold-down element 3 is at the outlet by a motor 12 driven. The motors 11 and 12 for driving the fastener tape 1 and the hold-down element 3 are synchronized, for example via an electric wave.

1

supporting belt

2

treated

3

Down member

4

Microwave rod antenna

5

Feuchtluftabsaugungsmittel

6

leadership

7

idler pulley

8th

Transport direction arrow

9

Direction arrow

10

Direction arrow

11

engine

12

engine

Claims (9)

Transport device for a microwave treatment plant with an endlessly circulating lanyard ( 1 ) for transporting the material to be treated ( 2 ) in a substantially horizontal transport direction ( 8th ), characterized in that above the fastener tape ( 1 ) at least one on the material to be treated ( 2 ) effective hold-down element ( 3 ) is arranged from microwaveable material. Transport device according to claim 1, wherein the hold-down element ( 3 ) consists of polytetrafluoroethylene (PTFE), polyethylene (PE), perfluoroalkoxy copolymer (PFA) or Fluorinatedethylenepropylen (FEP). Transport device according to claim 1 or 2, wherein the hold-down element ( 3 ) is formed as an endlessly circulating, flat screen belt, wherein the leading strand of the screen belt in a parallel plane of the fastener tape ( 1 ) is arranged such that it is the treated ( 2 ) on the lanyard ( 1 ) and fixed on it. Transport device according to claim 1 or 2, wherein the hold-down element ( 3 ) consists of substantially mutually parallel, endlessly circulating narrow bands or ropes, which are arranged such that their forward direction substantially parallel to the advancing direction of the fastener tape ( 1 ) and that they are the material to be treated ( 2 ) on the underlying lanyard ( 1 ) and fix. Transport device according to claim 4, wherein the narrow strips or ropes only in the edge region of the material to be treated ( 2 ) are arranged. Transport device according to one of the preceding claims, wherein the respective hold-down element ( 3 ) is drivable at a rotational speed which is substantially the same as the rotational speed of the fastener tape. Microwave treatment plant with a transport device according to one of the claims 1 to 6, wherein a plurality of treatment chambers in the transport direction one behind the other are arranged. Microwave treatment plant according to claim 7, wherein the microwave treatment plant as a multi-floor system with a plurality of superposed straps ( 1 ) with associated hold-down elements ( 3 ) is executed. Microwave treatment plant with a transport device according to one of claims 1 to 6, wherein the microwave treatment plant as a multi-day system with a plurality of superposed straps ( 1 ) with associated hold-down elements ( 3 ) is executed.