Device for initiating and/or promoting chemical or physical processes in a material

A device for initiating and/or promoting chemical or physical processes in a material, or specimen material, in which the material is heated in a reaction chamber (2) which is heatable by a heating means (3), in particular a microwave heating means, and thereby subjected to pressure, the material is firstly exposed to an initial pressure in the reaction chamber (2) and is then heated.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to a microwave heating device and more it concerns 
novel arrangements for moving a container for materials to be heated 
between loading and heating positions. 
DESCRIPTION OF THE RELATED ART 
In analytical chemistry and in particular for the preparation of materials, 
preferably specimen materials, or for the transformation of initial 
materials into reaction products it is common practice to perform the 
treatment under heat and pressure (excess pressure) as the desired process 
can only be realized or improved or forced under these conditions. 
In a device are described in the DE-A-39 33 992, by irradiation of a gas 
under pressure with long wavelength electromagnetic waves a shorter 
wavelength radiation is generated with which the initial materials are 
irradiated, or the initial materials themselves are placed under reduced 
pressure and are irradiated directly with the long wavelength 
electromagnetic waves. For this purpose there serves a device with a 
heating chamber surrounded by a housing on all sides and closeable in a 
sealed manner in which an initial material introduced into an open or 
closeable receptacle can be heated under reduced pressure which is 
generated by an air pump connected with the heating chamber (FIG. 1 and 4) 
or, in the case of a closeable receptacle, connected with the receptacle 
(FIG. 2 and 3 of this publication) by means of an evacuation line. 
A device of the kind mentioned in the introduction can be found in DE 40 38 
273 A1 in various configurations in which, for the purpose of opening a 
housing surrounding the reaction chamber, the side wall (FIG. 1), lid 
(FIG. 2) or base (FIG. 3) of the housing in DE 40 38 273 A1 is 
displaceable by means of a displacement device between the closed position 
and an open position. There is arranged, on the respective wall part of 
the housing which is to be opened, a mounting, e.g. a locating plate, for 
at least one specimen receptacle, so that the latter can be moved into the 
reaction chamber or out of it with the respective displacement movement of 
the wall part. Through this the placement and removal of at least one 
specimen receptacle in the reaction chamber or the housing is facilitated, 
but a special mounting for the at least one specimen receptacle is 
necessary. Also a simple positioning of the specimen receptacle(s) on the 
floor of the housing is not possible. Furthermore on account of the 
presence of the mounting device and also for further constructional 
reasons this known device is not constructed in a way that would allow the 
placing of the specimen material directly in the housing, i.e. without a 
special specimen receptacle. A further disadvantage of the known device is 
to be seen in that in the configuration with a liftable lid for the 
reaction chamber (FIG. 2) the accessability to the reaction chamber is 
very much restricted in the open position: although the lid is lifted from 
the housing, because of its position above the housing the accessability 
of the upper-side housing opening is made more difficult. 
A device of the kind under consideration can be found in WO/93/22650 in 
several configurations, in which, for receiving several pot-like specimen 
receptacles, a mounting device is provided in the form of a rotor in a 
reaction chamber, whereby the specimen receptacle can be inserted, by a 
horizontal movement, between a positioning plate engaging below the 
specimen receptacle and a lid which engages above the specimen 
receptacle--with its upper side opening--thereby effecting closure. The 
latter lid is part of the mounting device, which remains on the mounting 
device upon removal of the specimen receptacle. With this known device it 
is necessary to manually grasp the specimen receptacle upon insertion or 
withdrawal from the mounting device, which is possible only with 
difficulty in particular after the material treatment if only on account 
of the increased temperature. Furthermore it must be taken into 
consideration that the specimen material must be inserted into the 
mounting device purposively. Furthermore this known device is not suitable 
for a reaction chamber of larger dimensions, as manual handling is not 
possible on account of the resulting weight. In the event that several 
specimen materials are to be treated simultaneously several specimen 
receptacles are therefore required with this known configuration, which 
must be purposively inserted into their working positions with respective 
horizontal movements and withdrawn again after the treatment. 
SUMMARY OF THE INVENTION 
The object of the invention is further to configure a device of the kind 
mentioned in the introduction in such a way that a more simple loading of 
the reaction chamber is possible. 
This object is by means of a generally horizontal guide for displacing a 
material containing housing underpart relative to a lid after a lifting 
device has begun to lift the lid from a closed or working position and a 
ready position. 
With this embodiment according to the invention the housing underpart which 
encloses the reaction chamber or its lid is displaceable into an opening 
ready position not only by means of a lifting device, but the housing 
underpart or the lid is also displaceable approximately horizontally into 
a loading position and back again, so that the accessability of the 
reaction chamber is significantly improved and thus the specimen material 
or specimen materials can be placed directly or in specimen receptacles 
into the reaction chamber in a simple and ready way. The displacement of 
the lid or the housing underpart can be effected manually or by means of a 
motorised drive. For the approximately vertical displacement of the lid or 
the housing underpart a motorised drive is advantageous, as the weight 
involved must be overcome. Furthermore, such a displacement device can at 
the same time form the closure device for the housing. For the 
approximately horizontal displacement of the lid or the underpart of the 
housing a manual displacement in a guide is advantageous for the purpose 
of simplification of the device and its control. 
In the subclaims there are features which contribute to achievement of the 
object, simplify construction, make possible a simpler, faster and thus 
more economical and reliable treatment, improve energy consumption and 
economy and make possible an advantageous and reliable control of the 
treatment process. 
Further, the invention relates to a particular construction of the device 
which is distinguished not only by a simple and economical and compact 
construction, and convenient operation, but also ensures a high degree of 
utilization of the heating energy and can thus be operated economically 
and reliably. 
Furthermore, the invention relates to a further advantageous construction, 
in which the pressure regulation elements of the device are arranged in a 
particular constructional component which is separate from the reaction 
chamber, which may be connected with the reaction chamber merely by means 
of a connecting line, and to advantageous arrangements of pressure control 
elements such as valves, which ensure a trouble-free and reliable process 
development.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The main parts of the device which is generally designated as 1, are the 
reaction chamber 2, a heating device 3, in particular a microwave heating 
device, for the reaction chamber 2, a pressure loading device 4 for the 
reaction chamber 2, a pressure control block 5 for controlling the 
pressure in the reaction chamber 2, and a control device 6 for the 
functional control of the device 1, here in particular the heating device 
3 and the pressure acting, whereby the respective associated addressable 
control parts are connected by means of control lines of the control 
device 6. 
The material to be treated can be placed either directly or in one or in 
several receptacles in the reaction chamber 2. Insofar as one or several 
receptacles 7 (FIG. 2) are available, it may be advantageous for handling 
reasons to associate a carrier frame, in particular of plastics or 
microwave permeable or semi-permeable material, with the receptacle(s) 7, 
with which they may be readily placed in the reaction chamber 2 and 
removed again. 
For this purpose the reaction chamber 2 has an upper loading opening for 
the introduction and removal of the material to be treated. 
In the present embodiment the device 1 is a microwave-autoclave functioning 
with high temperature and high pressure for the treatment or preparation 
of materials, in particular specimen materials for analysis purposes. 
For controlling the pressure in the reaction chamber 2 several valves are 
provided, which are arranged in the separately arranged control block 5 
which is connected with the reaction chamber 2 by means of a connecting 
line 9, which may be either a rigid or a flexible pipeline or a hose line, 
in particular of plastics. 
The reaction chamber 2 is surrounded by a housing 11, which for the purpose 
of loading the reaction chamber 2 is preferably formed of a pot-shaped 
housing underpart 12 with an edge flange 12a and a preferably 
substantially flat lid 13 which is detachably fastenable to the housing 
underpart 12. The fastening device for the lid 13 on the housing underpart 
12 is not illustrated for reasons of simplicity. It may comprise either 
screws 11a which are schematically illustrated or oppositely arranged 
locking ring halves 11b of U-shaped cross-section which, horizontally 
opposed to one another, are moveable between a closing position (shown) in 
which they engage above the lid 13 and below the edge flange 12a and an 
outwardly offset release position (not shown) either by hand or by a 
motorised drive. 
The housing 11 is a metal housing. The microwave coupling into the housing 
11 is effected from below through a base 14 of the housing, which base is 
preferably arched downwardly. A cooling device generally designated as 15 
is associated with the housing 11, which has one or several cooling lines 
or cooling channels arranged either inside or outside along the walls of 
the housing 11, through which a coolant, in this case water, is delivered 
by means of a pump 16 and can be cooled in a cooler 16a. 
The housing 13 is preferably lined on the inside with a corrosion and heat 
resistant and preferably also heat-insulating lining material. With the 
present exemplary embodiment a pot-like lining part 17a which is adapted 
to the inner profile of the housing underpart 12 and a lining lid plate 
17b arranged on the lower side of the lid 13 are provided, which lining 
lid plate preferably engages into the lining part 17a with a projection 
17c projecting downwardly. 
Preferably there is present between the base part 17d of the lining part 
17a and the base 14 of the underpart 12 of the housing an additional 
plate-shaped lining base part 17e of microwave permeable material and/or 
plastics. For coupling the microwaves a preferably central opening 18 is 
provided in the base 14, in or below which a magnetron 19 or a waveguide 
or an associated radiation element such as an antenna 19a is arranged. On 
the upper edge of the opening 18 a bowl-shaped or hollow-ball 
section-shaped radiation element 21 of microwave-permeable material, 
preferably quartz, is arranged which is positioned in a correspondingly 
formed recess of the base part 17e. There may also be provided a radiation 
element in the form of a cylinder having a vertical axis, into which the 
antenna 19a penetrates in an aperture with play for movement. 
A supporting part for the housing 11 is designated as 20, on which the 
housing is arranged and, if appropriate, fastened. 
In the exemplary embodiment in accordance with FIG. 2 there is provided, to 
improve the sealing between the lining lid plate 17b and the upper edge of 
the lining part 17a, a sealing lip 17f, which is formed preferably in one 
piece on the lid plate 17b and engages into the lining part 17a and 
sealingly bears against the inner wall thereof. The lid plate 17b can also 
engage over the upper edge of the lining part 17a on the outside, in this 
case by means of an annular projection 17g projecting downwardly, which 
engages into an outer recess of corresponding cross-section on the upper 
edge of the lining part 17a. This upper edge 17a is thus tapered and 
engages into a corresponding annular groove 17i in the lid plate 17b. 
In the present embodiment in particular the base region of the housing 11 
is well heat-insulated by means of the base part 17d and the additional 
base part 17e. Therefore the cooling device 15 is arranged merely 
laterally next to the reaction chamber 2 in or on the sheath of the 
housing underpart 12, here in the form of an annular cooling channel 22 in 
the wall of the housing underpart 12 which in the present case is 
preferably circular in horizontal cross-section. 
Preferably the lid plate 17b sits on the lid 13 with an upper-side 
centering member 17.sub.1 in a corresponding lower-side recess. 
Furthermore, the lid 13 has a lower-side centering member 13a, in the 
present case a centering ring, which engages into the circumferential wall 
of the housing underpart 12 thus centering the lid 13 in its closed 
position. 
In the region of the housing 11 two temperature sensors T1, T2 are 
provided. The first temperature sensor T1 is in the base region of the 
housing underpart 12 and serves for determining actual values for the 
regulation of the heating power and thus also of the temperature in the 
reaction chamber 2. 
The second temperature sensor T2 serves for determining the sheath 
temperature of the housing 11 and for the regulation of the cooling device 
15, for the purpose of preventing an overheating of the material of the 
walls of the housing. 
The connecting line 9 is connected with the upper region of the reaction 
chamber 2, whereby it penetrates the lid 13 preferably centrally in the 
present embodiment. A relatively thin nominal cross-section suffices for 
the connection line 9. Preferably this nominal cross-section is approx. 6 
mm, whereby the connecting line 9 can preferably be a flexible line of 
plastics, in order to be able to move the lid 13 on closing and opening. 
With the exemplary embodiment in accordance with FIG. 2 the connection line 
9 branches in a T-shaped fitting 26 which is fitted or screwed into the 
housing 11, from above, here into the lid 13, from which a connection line 
branch 9a extends to the loading device 4 and the other connection line 
branch 9b extends to the control block 5. In the first-mentioned 
connection line branch 9a there are arranged an air- or gas pump 20 and a 
non-return valve 27 which opens in a flow direction towards the reaction 
chamber 2 and closes in the opposite direction. In the present embodiment 
the feed-through channel 9c, which forms the common connection line 
section--here in the lid 13, is lined with a sleeve 28, preferably with an 
inner flange 28a, of temperature and corrosion-resistant material, 
preferably plastics. The fitting 26 and associated threaded rings 26a, 26b 
and the connection line 9 are also of a temperature and 
corrosion-resistant material, in particular of plastics. 
The connection line branch 9b has a first blocking or regulation valve V in 
the control block 5, the valve member of which opens the branch 9b above a 
certain pressure or pressure range in the reaction chamber 2 with 
increasing pressure or closes it with decreasing pressure. The valve body 
of this valve V can be acted upon through the force of a spring e.g. a 
plate spring 29 or a spiral spring into its blocking position and can be 
opened through the pressure in branch 9b. In parallel therewith in the 
control block 5 two or three bypasses are arranged, in which respective 
control valves are arranged. An electrically operable valve V1 is 
associated with a first bypass 9b1 and a preferably smaller 
cross-sectional, which valve is electrically driven (open/close) or 
regulated in dependence of the pressure in the reaction chamber 2 in such 
a way that a certain pressure is not exceeded or a desired pressure value 
is maintained. A pressure-safety valve V2 is associated with a second 
bypass 9b2, which valve opens preferably abruptly above a higher, 
predetermined pressure in the reaction chamber 2. In the present 
embodiment this valve V2 is a rupture disk, which ruptures when the 
above-mentioned safety pressure value is exceeded and thus opens the 
bypass 9b2. The branch 9b is preferably dimensioned to be larger in 
cross-section than the first bypass 9b1. The second bypass 9b2 is 
preferably dimensioned to be larger still than the branch 9b. 
Preferably a further bypass 9b3 is provided in which an electrically or 
preferably manually operable valve V3 is arranged, which as a further 
safety valve serves for the purpose of reducing the pressure in the 
reaction chamber after a treatment process, by opening the valve, thus 
enabling the access to the reaction chamber, in the event that the 
preferably programm controlled valve V1 should not function, with which is 
also possible to reduce the pressure after the treatment process. 
The bypasses 9b1, 9b2, 9b3 are arranged in parallel to one another, i.e. 
each bypass can function independently of the others, which is ensured by 
the parallel connection. 
In the control block 5 there is also arranged a pressure sensor P1 for 
detecting the pressure in the reaction chamber 2, arranged in particular 
in the region of the connection line 9, which faces the housing 11. 
In the region away from the housing 11 the bypasses are rejoined to the 
common connection line branch 9b, the connection line branch 9b 
discharging into a container or chimney (not shown) in the further course 
of the discharge direction (see arrow 29). 
The material to be treated, in particular specimen material 31, can be 
introduced loose or preferably in one or several receptacles 7 into the 
reaction chamber 2. In the present embodiment there are shown two 
receptacles 7 which are open on the upper side, are in particular of 
hollow cylindrical shape and have a level receptacle base 7a, in which in 
addition to the specimen material 31 an additional material e.g. a 
reaction promoting material, in particular a solid or liquid chemical 32 
is further arranged. The horizontal cross-sectional size, in this case the 
diameter of the like receptacles 7, is only a fraction of the 
cross-sectional size of the reaction chamber 2, so that between the outer 
circumferential walls of an individual receptacle 7 and the inner 
circumferential walls of the reaction chamber 2, or between the latter and 
several receptacles 7 and between the receptacles, there is a free space 
which is preferably filled with a microwave absorbent, in particular 
liquid, indirectly effective heating agent, in the present embodiment 
water 33, up to approximately the height of the filling level of the 
receptacles 7. 
Preferably a further indirectly effective heating agent of 
microwave-absorbent material is provided, which in the present embodiment 
is a level heating plate 34, which rests on the preferably level upper 
side of the housing base 17d and on the level upper side 34a of which the 
receptacle(s) 7 are in extensive physical contact and thus in large-area 
heat conducting contact. 
The function of the device 1 is as follows: 
For the treatment, in particular the preparation of the material 31 this is 
introduced into the reaction chamber 2 as described above and the housing 
11 is closed. Thereafter the treatment of the material 31 under excess 
pressure and heat can begin, whereby the excess pressure, the heat and the 
treatment can be controlled automatically or manually. 
For a treatment process the loading device 4 is firstly switched on, in 
order to generate an initial pressure in the reaction chamber 2, in the 
present exemplary embodiment an initial pressure of e.g. 80 to 100 bar, 
which can be maintained through switching on the loading device 4 for a 
certain time or through the pressure sensor P1 or a further pressure 
sensor. The pressure is generated through introduction or pumping in of 
air or a gas, e.g. an inert gas such as nitrogen. Thereafter the heating 
device 3 is switched on, whereby in the present case the material is 
heated by microwaves directly from below (in as far as the material 
concerned is a microwave absorbent material) and the heating agent 33 and 
the heating plate 34 is likewise directly heated. On account of 
evaporation or reaction of material there is a significant increase in 
pressure and temperature in the reaction chamber 2 or in the pressure 
chamber, whereby the material treatment is performed under these 
conditions. 
Devices are provided with which certain temperature and/or pressure values 
or temperature and pressure ranges can be set or regulated, in order to be 
able to carry out the treatment at a certain pressure and/or a certain 
temperature. Thereby it must be taken into account that with regard to the 
effects of the above-mentioned measures, there are cross-over effects 
since the temperature may influence the pressure just as the pressure may 
influence the temperature (taking into account material reactions). 
It is advantageous to associate a processor with the control device 6 of 
the device 1 and to control the device in accordance with a program in 
such a way that a material treatment can be automatically performed. 
Below, regularly occurring operating process steps or operating process 
steps which are possible in dependence on pressure and temperature 
development will be described as an advantageous exemplary embodiment. 
In a first processing step a loading pressure which may range from zero to 
150 bar is generated in the reaction chamber 2 as a starting condition, by 
switching on the pump 20. Hereby, an initial gas pressure may be generated 
which may e.g. be approximately 80 bar. 
After reaching the loading pressure, which is detected by means of the 
pressure sensor P1 which delivers a corresponding signal to the control 
device 6, the heating device 6 is switched on as processing step two and 
the material is heated directly or indirectly in the above-described 
manner. An excess pressure is thereby generated in the reaction chamber 2, 
in a range up to approximately 150 bar with a simultaneous rise in 
temperature, whereby the treatment process takes place or is forced. With 
an excess pressure of e.g. approximately 120 bar the pressure sensor P1 
supplies a further pressure signal for the regulation of the electrically 
controllable valve V1, which in consideration of the pressure 
desired-value of 120 bar is actuated in the opening direction and in the 
blocking direction so that the desired pressure value is maintained. With 
this second processing step the heating power is also controlled or 
regulated (switch on/switch off) in accordance with a desired temperature 
value so that the desired temperature value is not exceeded, preferably 
maintained. 
In the case in which the pressure in the reaction chamber 2 exceeds the 
desired pressure value (120 bar), e.g. on account of a strong process 
reaction, as a further process step three the heating power is reduced or 
switched off, e.g. at a pressure value of 140 bar. 
In addition, as a further process step four, the pressure limiting valve V 
is provided, which operates at a pressure higher than the desired pressure 
value, e.g. at approximately 150 bar, and limits the pressure to this 
pressure value. The pressure-limiting valve V can be regulated in such a 
way that it operates only when the regulation or controlling of the valve 
V1 or the temperature regulation or control fails. 
As a further safety valve, in accordance with the next process step five, 
the safety valve V2 is provided, which for the purpose of explosion 
protection opens or ruptures upon a sudden large pressure increase. 
After completion of the process, the housing or reaction chamber 2 is to be 
subject to pressure release, in order to make access possible. In 
accordance with a further process step six, this can be achieved through 
opening the controllable valve V1 or valve V3. The valve V3, which is 
arranged in the additional bypass 9b3, is preferably a manually operable 
valve in order to be able to perform the pressure reduction even in the 
event that the valve V1 fails to function. 
The control block 5, which is preferably pre-installable as a 
constructional unit B, is of pressure-resistant metal, in particular of 
steel. For the purpose of corrosion protection the channels 9b, 9b1, 9b2, 
9b3 present in the control block 5 are lined with corrosion-resistant 
plastics. This may be effected in an advantageous manner in that firstly 
the channels are bored and are then lined with the plastics material, in 
particular by injecting the plastics. It is also possible to bore out the 
channels after their lining or to fill them with the plastics and then to 
bore out the plastics, so that the lining provides the channels. 
Below, further details and advantages of the device according to the 
invention will be described. 
The reaction chamber 2 is at the same time the pressure chamber and 
specimen chamber and it is protected from direct contact between the 
material and the pressure-resistant pressure wall--in particular of 
stainless steel --of the housing 11 by means of an insulating lining. The 
lining is of a plastics, in particular of PTFE, and serves as thermal 
protection and corrosion protection. The inner lining as well as the 
circumferential wall can be cooled by means of the cooling device 15, for 
the purpose of avoiding damage caused by heat. In the reaction chamber, 
the initial pressure is built up before the beginning of the reaction in 
order to avoid condensation and losses through evaporation of materials, 
in particular of solvents. Through the heating of the material 31 with the 
heating device 3 a further pressure increase to a regulatable operating 
pressure is achieved. The thus achievable increased boiling points prevent 
losses of elements and compounds. 
With spontaneous exothermal reactions the relatively large overall chamber 
volume, preferably approx. 3 to 3,5 dm.sup.3 provides an additional safety 
factor, as pressure peaks are avoided. Since, with the present embodiment, 
on account of the relatively large reaction chamber 2 a large quantity of 
material 31 can be introduced therein for treatment purposes, a relatively 
large heat of combustion may be released in the reaction chamber 2 during 
the treatment, which heat can however be taken up through the heat 
absorbing capacity of the indirectly effective heating agent 33 and 
through the relatively large chamber mass, so that temperature peaks 
arising from this cause are also avoided. Therefore, with the device 
according to the invention a large quantity of material 31 can be treated 
without functional problems arising. 
With the device according to the invention, the receptacles 7 preferably 
made of plastics may be of simple and economically producible 
construction, since they are subjected to the same pressure conditions 
inside and outside. Thus, differing reactions are also avoided, in as far 
as they are dependent on differing pressure conditions. Also losses and 
entrainments from one receptacle to another are reduced to values which 
can be practically ignored, as the boiling point of the substances 
(solvents, additional products etc.) is raised greatly on account of the 
pressure. I.e. treatments can be undertaken at increased temperatures and, 
despite this, with a closed system. 
The measures according to the invention also lead to an automatic boiling 
point increase through a pressure increase of the liquid medium which 
forms the indirect heating agent 33. With an initial or loading pressure 
of e.g. 100 bar a water boiling temperature of 311.degree. C. results. 
I.e. only when this temperature is exceeded does an automatic internal 
pressure increase in accordance with the vapour pressure curve of the 
heating agent 34 arise. Thus, e.g. at a water temperature of 330.degree. 
C. a vapour pressure of 129 bar ensues. For the application this means 
that with use of a low boiling-point heating agent a greater pressure 
automatically arises in the reaction chamber 2 than the evaporation 
pressure of the material (or components) 31 to be treated in the 
receptacle 7. 
For example, when using water as indirect heating agent 34 and nitric acid 
as material 31 to be treated or as auxiliary or reaction material. Boiling 
point of water approx. 100.degree. C. and boiling point of nitric acid 
approx. 121.degree. C. In this example the vapour pressure of the water is 
higher and thus prevents volatilization of nitric acid into the gas phase. 
Thus, condensation of the nitric acid in particular on the inner walls of 
the reaction chamber 2 is largely prevented. Only gaseous reaction 
products can theoretically enter the free reaction chamber space. This 
applies not only to the above-described decomposition example but to 
almost all chemical reactions with different solvents. This effect can be 
designated as automatic pressure compensation or adaptation. On account of 
the direct heat transformation of the microwave irradiation with solid 
and/or liquid materials (heating agents 33, 34) a sufficiently rapid 
regulation is possible, i.e. upon reducing or switching off the microwave 
power the temperature falls comparatively fast and through the control of 
the parameters the pressure offers a much higher safety standard with a 
faster reaction than conventional systems. 
For the above-described partially microwave absorbing material, a plastics 
is preferably suitable, in which material components such as particles of 
microwave-absorbent material, in particular graphite, are mixed or 
compounded, and which is known under the designation Weflon. 
For the lining, sleeve 28 and the heating plate 34 and if appropriate for 
the base part 17e, a corrosion-resistant material is required which is 
resistant to acids developing during the treatment of the specimen 
material, preferably polytetrafluoroethylene (PTFE/Teflon) or 
tetrafluoro-mixpolymerisate (TFM) or also quartz, ceramic or glass. 
With the exemplary embodiments in accordance with FIG. 3 to 5, the devices 
1 can be of the above-described construction and function. The details of 
the device 1 illustrated in FIGS. 1 and 2 are not illustrated in FIGS. 3 
to 5 for reasons of simplicity, as these embodiments are primarily to 
illustrate a displacement device, generally designated as 41, for the 
housing 11, with which the housing underpart 12 is easily and conveniently 
accessible for loading with specimen material or specimen receptacles 7 or 
auxiliary means 33, 34. 
The main parts of the displacement device 41 are an approximately 
vertically effective lifting device 42 and an approximately horizontally 
effective displacement device 43, with which a firstly approximately 
vertical and then lateral relative movement between the housing underpart 
12 and the lid 13 can be brought about, such that in its loading position 
44a, schematically illustrated in FIGS. 3 to 5, the housing underpart 12 
is with regard to the lid 13 relatively laterally displaced towards the 
operating side 45 and is thus readily accessible from above. With the 
lifting device 42, which in the embodiments in accordance with FIGS. 3 and 
5 engages on the lid 13 and engages into the housing underpart 12 in 
accordance with FIG. 4, these parts of the housing 11 may be separated 
from one another in an approximately vertical direction so that even if 
the lid 13 engages into the housing underpart 12 with a lower-side 
projection 17c, 17t, a relative lateral displacement of these parts from 
each other is possible. The latter may in each case be brought about by 
means of the displacement device 43, which in accordance with FIGS. 3 and 
4 engages into the housing underpart 12 and in accordance with FIG. 5 
engages at the lid 13. A guide 46, in which the housing underpart 12 
(FIGS. 3 and 4) or the lid 13 (FIG. 5) is movably guided for the relative 
lateral displacement, may be afforded through the cooperation of the 
lifting device 42 and the displacement device 43, as is shown e.g. in FIG. 
5 or it can also be provided as a particular guide element as is shown in 
FIGS. 3 and 4. 
In accordance with FIGS. 3 to 5, there are further provided the supporting 
part 20 for the housing 11, and abutments 47, 48, 49 for the lifting 
device 42 the displacement device 43 and the supporting device 20 for 
their support. The supporting part 20 and the abutments 47, 48, 49 can be 
parts of an apparatus into which the device 1 is integrated. 
With the exemplary embodiments in accordance with FIGS. 3 to 5 the lifting 
device 42 and the displacement device 43 are formed by respective 
pneumatic or hydraulic piston cylinders 51, 52 which can be acted upon in 
both displacement directions. With the embodiment in accordance with FIG. 
3 the piston cylinder 51 forming the lifting device 42 is arranged 
coaxially between the lid 13 and the associated abutment 47 in an 
approximately vertical position, with the housing 11 closed. The piston 
cylinder 52 which forms the displacement device 43 engages on the housing 
underpart 12, whereby it is on the side away from the operation side 45 
and extends in approximately horizontal direction. The piston cylinder 51 
is preferably rigidly connected with the abutment 47 and the lid 13, so 
that an approximately vertical guide 50 is provided for the movement of 
the lid 13. The approximately horizontal guide 46 for the lateral 
displacement of the housing underpart 12 can e.g. be formed by a 
longitudinal recess 59 in the supporting part 20 which is formed as a 
plate, as is shown in FIG. 3, or the guide 46 can also be formed by the 
piston cylinder 52. For controlling the piston cylinder 51, 52 a pneumatic 
or hydraulic control device 6a is provided, which is connected by fluid 
lines with the double-acting piston cylinder 51, 52 and by control lines 
with the control device 6. For opening the housing 11 firstly the lid 13 
is slightly lifted through a corresponding action upon the piston cylinder 
51. Thereafter the piston cylinder 52 is activated and the housing 
underpart 12 is displaced from its working position 44 shown in continuous 
lines approximately horizontally in the guide 46 into the loading position 
44a. The closing of the housing 11 occurs in reversed displacement or 
control steps, i.e. firstly the housing underpart 12 is displaced back 
into its working position 44 and then the lid 13 is lowered from its ready 
position 444b into the closing position. 
The exemplary embodiment in accordance with FIG. 4 differs from the 
above-described embodiment in that the lid 13 is fixedly fastened to the 
abutment, e.g at the abutment 47, and the supporting part 20 is in this 
case approximately vertically displaceable by means of the lifting device 
42 which is e.g. also formed by a piston cylinder 51. In this embodiment 
it is advantageous to mount the piston cylinder 52 which forms the 
displacement device 43 in joints 61, 62 with joint axes running at right 
angles to the vertical plane of movement, between the housing underpart 12 
and the associated abutment 48. With this arrangement, for opening the 
housing 11, the housing underpart 12 is slightly lowered into the ready 
position 44b and then the housing part 12 is displaced by means of the 
piston cylinder 52 into the loading position 44a. The closing of the 
housing 11 occurs with reversed displacement or control steps. 
The exemplary embodiment according to FIG. 5, according to which the same 
or similar parts are also designated with the same reference signs, 
differs from the exemplary embodiment according to FIG. 3 in that the 
lifting device 42 and the displacement device 43 or both piston cylinders 
51, 52 engage on the lid 13 and also the piston cylinder 51 which forms 
the lifting device 52 is mounted in joints 63, 64 with joint axes running 
at right angles to the vertical plane of movement of the lid 13. The 
displacement control of the piston cylinders 51, 52 corresponds therewith, 
whereby however only the lid 13 is firstly displaced into the ready 
position 44b and then into the open position or loading position 44a away 
from the operating side 45. On account of the double coupling of the lid 
13 an integrated guide 46 results in this case. The piston rod of the 
piston cylinder 51 can be pushed out upon movement into the open position 
58 or can be pulled out by the piston cylinder 52. The closing movement 
occurs correspondingly in reversed displacement steps. 
The apparatus in FIG. 6, generally designated as 71, with the integrated 
device 1, has a quadratic housing 72 which in its forward region, towards 
the operating side 45, has an approximately horizontal working plate 73 of 
a height h, approximately that of a table. In its rearward region the 
housing 72 is heightened in stepped manner through an assembly 74. The 
integration or arrangement of the device 1 in the apparatus 71 is such 
that the housing 11 is in the rear region thereof when in its working 
position, i.e. below the assembly 74, whereby the housing underpart 12 is 
displaceable towards the operating side 45 into the forward region of the 
apparatus 71, so that in the loading position 44a it is in the vicinity of 
the forward side 75 of the housing 72 and its edge flange 12a is in the 
region of the working plate 73, preferably projecting slightly upwardly 
above this plate. For this purpose the working plate 73 has an elongate 
aperture 76 which extends forwardly from the rear, the elongate aperture 
mid-points of which are in the working position 44 and in the loading 
position 44a for the housing underpart 12. Of the displacement device 41, 
in FIGS. 6 and 7 only the lifting device 42 for the lid 13 and parts of 
the displacement device 43 for the housing underpart 12 are shown, namely 
the supporting part 20 in the shape of a carrier ring 20a, in which the 
underpart of the housing 12 is positioned with a stepped taper on the 
lower side, and the guide 46, here in the form of two guide rods 46a which 
are arranged on the two sides of the housing underpart 12, on which the 
carrier ring 20a is mounted with running sleeves 46b to be freely 
displaceable by hand between the working position 44 and the loading 
position 44a. In order to enable the displacement movement of the housing 
underpart 12 and the lid 13, the signal, control and supply or discharge 
lines extending thereto are formed flexibly, as in the embodiments 
according to FIGS. 3 to 5. The guide rods 46a are mounted in their end 
regions in the housing 72. Of the device 42 the piston cylinder 51 is 
visible in FIG. 6. The abutment 47 associated therewith is part of the 
apparatus 71 or of its housing 72 and can e.g. be formed by a tie bar 
and/or the upper wall of the housing 72. 
A suction device 81--not shown in FIGS. 1 to 5--is associated with the 
device 1 in all present embodiments, for drawing off the vapours which 
emerge from the opened housing 11. The suction device 81 has a suction 
opening 82 which is arranged behind the housing 11 at the height of the 
opening slit which is formed upon the opening of the lid 13, preferably in 
the form of a horizontal, transversely extending slit, to generate a broad 
suction stream 83 which extends approximately horizontally, covering the 
entire width of the opening of the housing underpart 12 and preferably 
being so strong that it may also draw off the vapours which emerge from 
the housing underpart 12 in the loading position 44a, in the present 
embodiment from the front to the rear. The drawn off vapours can be 
discharged through a continuing discharge line 84, passing through the 
housing 72 to the outside, outside the building present, or to a chimney 
(not shown). 
A guide sheet 85 extending approximately horizontally is provided on the 
one hand for improvement of the draw-off, and as a mechanical safety 
device on the other hand, which is positioned at a small spacing of 
approximately of few cm above the opening of the housing underpart 12 in 
the loading position 44a and is mounted displaceably between its working 
position covering the opening and a release position which exposes the 
opening. With the present embodiment the guide plate 85 is arranged to be 
upwardly tiltable from the opening, e.g. to the side or in accordance with 
FIG. 6 to the rear. For this purpose, there may serve hinges 86, which in 
the present embodiment are arranged between the rear end of the guide 
sheet 85 and the neighbouring front side of the assembly 74 and are 
fastened thereto. Preferably the guide sheet 85--viewed from the 
front--with laterally angled limbs 85a, has the cross-sectional shape of a 
U standing on its head, so that the spreading of the emerging vapours to 
the sides is hindered and the guidance of the suction stream 83 and the 
suction is improved. The lateral limbs 85a preferably stand on the working 
plate 73. In its covering working position the guide sheet 85 protects the 
open housing underpart 12 not only from impurities, which might fall into 
it, but it is also a protection device against the danger of the hands of 
the operating person being squashed when the housing underpart 12 is 
displaced into the loading position 44a. Therefore it is advantageous for 
safety reasons to design the controller of the device 1 in such a way that 
the housing underpart 12 can be displaced into the loading position 44a 
only in the working position of the guide sheet 85. This may be realized 
by means of a contact maker 87 on the housing, which is actuated by the 
guide sheet 85 in its working position and is connected with the 
corresponding control device 6, 6a by means of a signal line. 
The guide sheet 85 preferably consists of transparent material, in 
particular of plastics, such as plexiglas or the like, to enable viewing 
into the housing underpart 12. 
The broad surface parts 85a of the working plate 73, present to the two 
sides of the guide sheet 85, may serve as placement surfaces e.g. for 
specimen receptacles 7. 
The closure ring halves 11b, which are also present in FIG. 6, can be 
actuated by a drive motor. They can each be pivotally mounted at their 
respective ends in a joint 88 with a vertical joint axis 88a, which is 
preferably arranged behind the housing 11 and is fastened to the housing 
72 or to components attached thereto. The drive motor (not shown) can be 
arranged in the region of the joint 88 or can be integrated therein. 
Before the opening of the housing 11 by means of the lifting device 42 the 
closure ring halves 11b or another closure means are to be released, and 
upon closure are to be closed after the lifting movement. 
Preferably the conductive housing underpart 12 which is in particular of 
corrosion-resistant material such as metal, in particular stainless steel, 
is fabricated in one piece with its base 14 and is continuously connected 
thereto, whereby it is very stable.