DE3934175C1 - Solid raw material melting appts. for perfumes mfr. - has container arranged inside microwave chamber and combined with stirrer - Google Patents

Abstract

Solid raw material for perfumes are melted gently in a container (2) inside a microwave chamber. The container (2) encloses a polyethylene barrel with a stirrer (4) made of material permeable to microwaves, such as glass fibre reinforced polyethylene. The drive shaft (5) of drive motor (7) for the stirrer (4) passes through the microwave chamber in a bush, made of radiation protection materials (8) which prevents the efflux of microwave radiation. ADVANTAGE - Increase of heat convection within container heated by microwave radiation, without loss due to metal stirrers.

Description

The present invention relates to a new device for gentle melting of solid perfume raw materials Microwave energy.

From DE-AS 10 60 354 it is known that organic solid can melt materials with microwave energy gently by the microwave radiation as a function of the mass flow of the material to be melted and the melting and dissolving process do siert. The material to be melted can be from the microwaves generator are moved past or flow past or this opposite to be arranged stationary. An inhomogeneous through radiation of thicker layers leading to product changes has not been observed.

In the earlier application P 39 22 299.3-23 it is described that homogeneous mixtures of solid perfume raw materials can be produced by using mixtures thereof, which are partly in a liquid and partly in a solid or wax-like state, by using ultrasound or microwaves in an energy-saving manner can be brought into a liquid state for a short time. In this older application it is further described that for melting larger amounts of solids microwave chambers with 5-10 m ³ content and power of 50-150 kilowatts are available.

As far as larger amounts of the substances to be melted in Transport drums or containers made of polyethylene or Polypropylene, d. H. a microwave-permeable material are present, it is advantageous to melt them directly into them Containers and thereby the often tedious emptying the solid ingredients in their own melting tank spare.  

Surprisingly, it has now been found that at microwave radiation, for example of a polyethylene With 100 kg of solid matter, the contents are in the center warms up much faster than in the outside areas, so that there may be local overheating inside the outside areas are also melted. This is Surprisingly, since the microwave chamber is one with "wilder Radiation "is used, i.e. a microwave chamber in which by arranging the magnetrons and mirroring them on the External walls of the chamber a practically uniform energy density prevails in all areas of the chamber and in itself should be expected that by partial absorption of the Microwave energy in the outer areas of the melting tanks lower, if any, energy density inside should rule. A corresponding energy distribution will for example, ent melting water or ice ent holding substances observed in the microwave, where the average penetration depth is only 3-6 cm and thicker layers not directly from the microwave radiation, but are melted inside by heat convection have to.

Because with many organic substances, especially with the very sensitive perfume raw materials, local overheating when opening melt lead to damage to the substance, it seemed therefore first of all necessary to reduce the energy density so far, that local inhomogeneities of the energy supply, d. H. esp in particular, overheating in the core of the melting container the normal heat convection can be compensated. This can can be achieved by appropriate temperature control, where on the one hand the "core temperature" in the center of the Treated goods, on the other hand, measured the infinitely variable Energy supply of the chamber is regulated so that a defined one Maximum temperature is not exceeded. However, this would have been means to delay the melting process considerably, since the Heat convection in the just above the melting point lying liquid phases due to the high viscosity only is low.

It is therefore the task of a device to find by using the heat convection within a Microwave radiation heated melting tank can be increased can.

This problem is solved by the characteristic Features of claims 1 and 2 respectively.

The problem here is that conventional stirrers, their drive systems are made of metal within the microwaves Chamber can not be used because they are under Circumstances act as microwave antennas and are slightly up about the ignition temperature of the organic to be melted Can heat substances, or sparks or arcs between Magnetron and stirrer may occur, which may be a Explosion of the ignitable mixtures could trigger.

The necessary mixing can therefore either aims to periodically remove the melting container from the micro shaft chamber is removed and externally with an agitator Content is mixed, or that the microwave chamber ge opens and a corresponding agitator is moved in, where of course the microwave radiation abge must be switched. Both methods have the disadvantage that the Melting process is interrupted again and again and thereby ver is slow.

Such agitators are of many designs for other purposes known shapes. One example is the particularly effective ones Stirring devices according to DE-AS 17 57 113 and DE-OS 19 08 983 referred.  

It is more advantageous to use a corresponding radiation trap the wall has a wave made of microwave-permeable material, for example plastic or in particular glass fiber, coal fiber or porcelain fiber reinforced plastic, at the end of an agitator or agitator from ent speaking material, which is in the melting range immersed in the melting tank. Through one of the micro wave shielded external motor can do the whole System are then powered.

An alternative is to use a double tube as well microwave-permeable material in turn from the outside through a Introduce radiation trap into the melting area and outside the microwave chamber by means of a circulation pump to circulate molten material through the double pipes.

Circulation systems for stirring and homogenizing containers hold are known for other purposes. An example is the DE-OS 15 57 197 and the methods described therein sen. Particularly suitable for mixing liquids static mixers in such circulation systems are for example described in DE-PS 28 10 648. That such stirring method however special in connection with microwave radiation could have parts when melting perfume raw materials, cannot be inferred from this.

The invention is described in more detail in the following figures.

Fig. 1 shows a microwave chamber with integrated stirrer,

Fig. 2 shows a microwave chamber with mixing pump,

Fig. 3 shows a microwave chamber with an external stirring device.

Fig. 1 shows the microwave chamber ( 1 ) with the set melting container ( 2 ) in the form of a polyethylene barrel, through the opening ( 3 ) of which a stirrer ( 4 ) with a stirrer made of microwave-permeable material (e.g. glass fiber reinforced polyethylene) is inserted. The shaft ( 5 ) is guided to the outside through an opening ( 6 ) in the ceiling of the microwave chamber and driven by a motor ( 7 ). A radiation protection grid ( 8 ) prevents the microwave radiation from escaping. The mounting of the motor and the bearing of the shaft on the housing of the chamber have not been reproduced in order not to make the figure appear confusing.

In FIG. 2, the microwave chamber (1) is again shown with a set serving as the melting vessel Polyethylenfaß (2) through the opening (3) a double tube (4 A / 4 B) is guided, which via an opening (6) is led out of the microwave chamber. The opening ( 6 ) is additionally secured with a radiation protection grille ( 8 ) to prevent microwave radiation from escaping. A static mixer ( 9 ) in the suction line can additionally ensure that the material sucked in is thoroughly mixed. The pump power is brought about by the pump ( 10 ), the pump having to be designed in such a way that it does not damage the material to be conveyed. Diaphragm pumps, peristaltic pumps or the like, in which the substances to be conveyed do not come into contact with metallic surfaces, are therefore particularly preferred.

Fig. 3 shows a microwave chamber with retractable stirring device, the microwave chamber ( 1 ), a melting container ( 2 ) is shown with a further opening ( 3 ) through which the stirring head ( 11 ) of a Turobo stirrer is inserted, which via a drive motor ( 7 ) and the shaft ( 5 ) is driven. The stirring head and motor are lowered or extended again by the height-adjustable linkage ( 12 ) via a correspondingly wide opening ( 13 ) in the ceiling of the mixing chamber. In the extended state of the stirrer, the cover ( 14 ) closes the opening ( 13 ) so that microwave radiation cannot penetrate through to the outside.

Claims (4)

1. A device for the gentle melting of solid perfume materials, consisting of a melting container arranged in a microwave chamber, characterized in that the container ( 2 ) is connected to a mixing device which from an external circulation pump ( 10 ) and supply and return lines ( 4 A, 4 B) to the melting tank ( 2 ) and optionally a static mixer ( 9 ) in one of the lines. 2. Device for the gentle melting of solid perfume substances, consisting of a melting container arranged in a microwave chamber, characterized in that the container ( 2 ) is connected to a mixing device which consists of a paddle stirrer ( 4 ), preferably a turbo stirrer ( 11 ) , or a screw mixer, which ent either through lifting devices ( 12 ) and microwave-proof closable openings ( 13 ) from the outside into the microwave chamber ( 1 ) or the melting tank ( 2 ) and can be extended in microwave operation or made of suitable plastics or glass, carbon or porcelain fiber reinforced plastic and is attached in the melting container ( 2 ) and is driven by a shaft ( 5 ) which protrudes from the microwave chamber ( 1 ) via a radiation trap ( 8 ). 3. Device according to claims 1 or 2, characterized in that the microwave chamber ( 1 ) has a uniform microwave radiation distribution and an energy supply of 0.1-100 kW / h / kg solids. 4. Device according to one of claims 1-3, characterized in that the microwave energy can be regulated and control elements and temperature sensors in the melting tank ( 2 ) are present, which regulate the energy supply.