WO2019013682A1

WO2019013682A1 - Cartride/casette for improved heating of dielectric loads

Info

Publication number: WO2019013682A1
Application number: PCT/SE2018/000017
Authority: WO
Inventors: Lars Ekemar
Original assignee: Lars Ekemar
Priority date: 2017-07-13
Filing date: 2018-07-03
Publication date: 2019-01-17
Also published as: SE540805C2; SE1700146A1

Abstract

This invention relates to a device which allows for the flexible and economical thawing and heating of dielectric loads at frequencies between 50 kHz and 1500 MHz. The device is characterized by a container/cartridge (Fig. 1 (6)) made of a non-conductive electrical material which is equipped with antennas (Fig. 1 (5)). The container/cartridge is placed in a cavity in which there are connections to the container antennas. The container is designed in accordance with dedicated dielectric loads.

Description

Cartridge/cassette for improved heating of dielectric loads.

The requirement to be able to thaw and heat loads of different sizes and of different types of organic materials has increased.

The sizes of loads can vary between 10 grams to several kilograms. The nature and sensitivity of loads may also vary

For example, living cells such as stem cells are stored as frozen. The viability of cells depends on the thawing time. The shorter thawing time, the better viability. In the field of medical care there is a need for rapid thawing of blood plasma and the warming of red blood cells prior to transfusion. These loads are very sensitive and under no circumstances should they even partially overheat above 40 ° C.

Established heating techniques such as microwave heating and heating with heat radiation and thermal convection have in common that heat absorption in load is characterized by trifling depth of penetration and negligible heating of inner parts by heat transport from heated surface areas.

Thawing volumes exceeding a few milliliters of living cells, the thawing time is far too long for obtaining acceptable viability.

It has also been previously known that by emitting electromagnetic radiation / fields from an antenna/antennas in a cavity with electrically conductive walls/case, it is possible to heat dielectric materials placed in the cavity. (Patent No. SE9400777-0 and Patent No. SE9703033-2). It is also known that you can use dielectric materials in order to equalize an electromagnetic field

(EP02727030.5).

One of the disadvantages of equipment intended for this type of thawing and heating is that they are manufactured in small volumes and are often dedicated to only one application such as thawing of frozen blood plasma and/or thawing of frozen living cells, thereby they become very costly.

Because of cost reasons there is a need of a standard equipment for dielectric thawing / heating in the range of 50kHz-1500 MHz capable of handling loads from a few milliliters to several liters. The present invention solves this problem.

A thawing/heating device according to the invention consists of a cavity made of one or many different electrical conductive materials to which it is connected one or more frequency generators. In a container/cartridge/cassette made of an electrically non- conductive material, a dielectric load is to be heated / thawed. The container/cartridge/cassette is provided with openings/doors. The cartridge is after that placed in the cavity.

The frequency generators are electrically connected to impedance matching/adjustments, which are electrically connected, through grommets in the cavity wall/case, to antenna antennas with which the container/cartridge is equipped. The antenna/antennas may preferably be mounted on the surface of the container.

The adjustments can be passive and/or active. The frequency generators are electrically grounded in the cavity outer casing.

Cavity, the load, the antenna in the cassette, the impedance matching unit and frequency generator are in resonance. Impedance adjustment is either reactive and/or by frequency adjustment. A feature of the invention is that it consists of a container / cartridge consisting of electrically non conductive material, the material having a dielectric constant below 10, still more preferably below 7 and most preferably below 5.

The basic idea of the invention is that there are a number of different containers / cartridges which are designed in such a way that they can be placed in the heating equipment and that the container / cartridge in question is designed for a dedicated load. The cartridge can therefore be included as a unit in the resonant circuit/resonant circuits. For this reason, the container / cartridge may be fully or partially provided with/consisting of a metal surface/electrically conductive material that is electrically connected to the cavity. The cartridge may be of different design with respect to geometry, location of antenna discs, metal surfaces which are in electrical contact with the cavity. There may also be metal details in the container/cartridge that are in electrical connection with the cavity.

All in order to create oscillating electric fields designed for thawing heating requirement.

The cartridge/container to be used to prepare roast beef looks quite different from the

cartridge/container intended to thaw blood plasma or living cells.

A dielectric load is placed in the container and the container is then placed in a cavity (consisting of a metallic material) in which there is one or more connections that connect to the metal plate/plates mounted on/in the container/cartridge.

The connection connections are electrically connected with a frequency generator via a grommet in the cavity wall. Between the frequency generator and the grommet there is an impedance adjustment (matching unit). The frequency generator is grounded in the cavity.

The cavity, the load, the antenna in the container/cartridge the impedance matching adjustment and frequency generator are at applied frequency/frequencies in resonance. Impedance

matching/adjustment is either reactive and/or by frequency adjustment.

Fig. 1 is an example of the invention.

The frequency generator (1) is electrically grounded in the cavity (3) via adaptations/matching unit (2), the oscillating electrical current is led via a grommet (4) through the cavity floor to an antenna plate (5) in the cartridge/cassette (6), the dielectric load (7), the metal coated upper side of the cartridge/cassette (8) and the electrical connection between the cassette and the cavity (9).

From the figure it can be seen that the frequency generator, the adaptation/matching unit, the antenna, the load, the cassette upper side and the cavity form a resonance unit.

Fig. 2 is a further example of the invention. The cartridge (A) is viewed from the side. The cartridge has double bottoms. In the upper bottom there is a recess (B). The recess is located over an antenna disc (C). In the case of thawing, for example blood plasma, leakage occurs. Frozen blood plasma is stored in bags made of plastic material. In case of leakage from the bag, the recess is filled. The impedance conditions in the resonant circuit are affected, the system detects the change and the thawing process is interrupted. The disadvantage of that solution is that it is relatively insensitive. A better solution is that the upper bottom has one or more holes. The space between the bottoms is filled with blood plasma, the impedance conditions in the resonant circuit are affected and the thawing process is interrupted. This is not limited to blood plasma, for example it may also be beef juice from a roast beef while cooking or any other liquid with dielectric properties.

The cartridge / container can also be filled in whole or in part with field equalizing material that completely or partially surrounds a dielectric load. This in order to improve the thawing and / or heating conditions of sensitive dielectric loads.

The object of the invention is to have a number of different cartridges which are designed in such a way that they can be placed in the heating equipment and the cartridges is designed for a dedicated load or load type. The cartridge is included as a device in the resonant circuit/resonant circuits. The cartridges to be used to prepare roast beef looks quite different from a cartridge intended for the thawing of blood plasma.

The cartridge can be designed entirety in electrically conductive material in which it is placed antenna / antennas. The cartridge is then placed in the cavity.

The purpose of this is, for example, to create a sub-cavity in which smaller loads, such as living cells, can be thawed/heated.

Claims

1. Devise for thawing/heating of dielectric materials/dielectric load (Fig.l (7)) with electromagnetic radiation within the frequency range of 50 kHz to 1500 MHz characterized by a container / cartridge (Fig.l (6)) consisting of an electrically non-conductive material, equipped with antennas/antenna discs (Fig.l (7)).

2. Device according to the preceding claim, characterized by that the container/cartridge is placed in a cavity (Fig 1 (3)) consisting of electrically conductive material.

3. Device according to any of the preceding claims characterized by that connections in the cavity come into electrical contact with the antenna disc/ antenna discs with which the cartridge is equipped and that the tenriinals, one or more, are electrically connected to one or more frequency generators.

4. Device according to any of the preceding claims, characterized by that cavity, load, antenna of the container/cartridge and impedance matching and frequency generator is a resonance unit.

5. Device according to any of the preceding claims, characterized by that the container/cartridge is wholly or partly provided with/consisting of a metal / metal surface / electrically conductive material which is electrically connected to the cavity.

6. Device according to any of the preceding claims, characterized by that the container/cartridge is equipped with metal parts which are electrically connected to the cavity.

7. Device according to any of the preceding claims, characterized by that antenna discs / antenna discs are preferably located on / in the sides of the container/cartridge/cassette.

8. Device according to any one of the preceding claims, characterized by that the container / cartridge (Fig. 2 (A)) has a double bottom and an antenna disk (Fig. 2 (C)) is located on the lower bottom and there is a recess in the upper bottom, when the recess is filled with dielectric fluid, the impedance conditions change and a signal is generated and/or the process is stopped.

9. Device according to any of the preceding claims characterized by that the container/cartridge has a double bottom and that an antenna disc is located on / in the lower bottom and there is a hole in the upper bottom, when the gap between the upper and lower bottoms is filled in whole or in part with dielectric fluid changes the impedance conditions and a signal is generated and / or the process is stopped

10. Device according to any of the preceding claims, characterized by in that the

container/cartridge is fully or partly filled with field-equalising dielectric material which completely or partially surrounds a sensitive dielectric load.