JP7219564B2 - tubular furnace equipment - Google Patents

Description

The present invention relates to a tubular furnace apparatus for a nuclear reactor and a nuclear reactor, in particular for atomic absorption spectroscopy. A tube furnace apparatus includes a sample support and a sample support. The sample support device has a receiving tube that forms a tubular receiving space. The sample support serves to contain the analyte and is arranged within the containing space. The sample support device has two bearing extensions on the containment tube which serve to hold and electrically contact the tubular reactor device to the nuclear reactor. The bearing extension extends transversely, preferably perpendicularly, to the longitudinal axis of the containment furnace. The sample support has a support projection, and the sample support is joined with the storage tube wall of the storage tube using the support projection.

Atomic absorption spectroscopy (AAS) reactors, particularly graphite furnace atomic absorption spectroscopy (GF-AAS) reactors, in which a graphite furnace or graphite tube is warmed by electrothermal treatment to atomize the analyte are sufficient. known to Graphite furnaces or tube furnace devices generally have a sample support device with a receiving space which is formed in the shape of a tube. Inside the tubular receiving space, the analyte can be atomized directly in the receiving space or on, for example, a dish-shaped table or sample support within the receiving space. For optical spectrum analysis, the longitudinal end of the tubular receiving space is always open. The tubular receiving space is formed by the receiving tube of the sample support device made of graphite. The receiving space or receiving tube may be heated longitudinally or transversely. That is, the electrical current for heating may flow from the longitudinal end of the encasing tube to the longitudinal direction of the encasing tube, the encasing tube being electrically contacted via bearing extensions facing each other on its exterior to provide an electric current. may flow through the containment tube in a direction transverse to the longitudinal axis of the containment tube. The bearing extensions are each retained and electrically contacted to the reactor housing. In contrast to longitudinal heating of the receiving tube, transverse heating results in relatively good temperature constancy over the entire length of the receiving space.

In order to ensure the reproducibility of the measurement results, it is important that the heating of the analyte is performed indirectly via the containing tube. For this reason, current flow through the sample support that could result in direct heating of the analyte should be prevented as much as possible. For this reason, in the transversely heated tubular furnace devices known in the prior art, the sample support is always fixed to the containment tube wall of the containment tube by means of a single support prong, or is joined to the containment tube wall. It is Thus, tubular furnace devices are known in which a hole is formed in the containing tube wall into which a single support projection of the sample support is inserted. A support barb is formed to be inserted into the hole centrally and on the underside of the sample support. In this case, the holes must be elongated in order to correctly align the sample supports within the receiving tube. This has the disadvantage that it is difficult to form matching slots and support projections according to the tolerances to be observed. In addition, in the region of the support stem, heat is conducted directly from the containment tube to the sample support, thereby undesirably directly heating the analyte, which is typically centrally located on the sample support. be done.

Furthermore, tubular furnace devices are known in which the sample support is of dish-shaped design. In this case, the sample support is held on the receiving tube wall along the longitudinal edges of the sample support. Thereby, the sample support is integrally joined with the sample support device with its longitudinal edges to a single supporting projection formed on the wall of the receiving tube. For this reason, the sample support is integrally formed with the sample support device by cutting. This is relatively expensive and thus incurs high costs. Also in this case an undesired direct heating of the analyte takes place at the longitudinal edges of the sample support via the support lugs.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a tube furnace apparatus and an analytical instrument which respectively provide more accurate measurement results at lower production costs.

This task is solved by a tubular furnace apparatus having the features of claim 1 and an analytical instrument having the features of claim 17 .

A tubular furnace apparatus according to the invention for a nuclear reactor, in particular for atomic absorption spectroscopy, comprises a sample support device and a sample support. The sample support device has a receiving tube that forms a tubular receiving space. The sample support serves to contain the analyte and is arranged within the containing space. The sample support device has two bearing extensions on the containment tube which serve to hold and electrically contact the tubular reactor device to the nuclear reactor. The bearing extension extends transversely to the longitudinal axis of the containment furnace, preferably perpendicular to the longitudinal axis. The sample support has a support projection with which the sample support is joined to the receiving tube wall of the receiving tube. The sample support has two support lugs formed on opposite longitudinal ends of the sample support.

In particular, two support projections are formed at opposite longitudinal ends of the sample support, which makes it possible to arrange the sample support with two points on the receiving tube wall. By arranging two bearing extensions to the receiving tube, the current for heating the receiving tube can flow through this receiving tube only transversely to the receiving tube, so that the sample support: Placed in a containment tube without potential. This ensures indirect heating of the sample support. Current flow through a sample support based on two support lugs, or based on supporting the sample support at two points on the containment tube wall, is determined by the number of support lugs at each longitudinal end of the sample support. A relatively large relative spacing can also prevent this. The resulting electrical resistance prevents current flow through the sample support, ie direct heating of the analyte. At the same time there is direct heat conduction from the containment tube wall to the sample support only at its longitudinal ends, and the analyte, which is usually placed in the center of the sample support, is actually affected by this heat conduction. do not have. Furthermore, a sample support or a tubular furnace apparatus with two support lugs at the longitudinal ends of the sample support can be produced particularly easily, ie cost-effectively.

The sample support has only two support prongs. If the sample support does not have more than two support prongs, the improved indirect heating of the analyte can improve the quality of the measurements that can be obtained. At the same time, it is also possible to easily arrange or arrange the sample support inside the receiving tube. It is therefore possible to form the sample support independently of the sample support and then easily install the sample support together with the sample support to the tube furnace apparatus.

It is particularly advantageous here that the tubular furnace apparatus consists entirely of graphite. At this time, the sample support device and the sample support can be manufactured separately from each other by cutting. Furthermore, the entire tubular furnace apparatus or individual parts thereof may be coated with a pyrolytic treatment. Thereby, the life of the tubular furnace apparatus can be extended.

In particular, the receiving tube may be formed so that it can be electrically heated in the transverse direction via the bearing extension. In this way, temperature constancy can be ensured over the entire length of the containment tube.

The bearing extension may consist of a bearing body and a retaining bridge, wherein the retaining bridge may join the bearing body with the receiving tube. The retaining bridge can be molded into the receiving tube and the bearing can be molded into the retaining bridge. That is, the receiving tube may be constructed integrally with the two bearing extensions. The sample support device configured in this manner can be manufactured by cutting a graphite body. If each bearing and retaining bridge is formed like a continuous section in the direction of the longitudinal axis of the receiving tube, it forms a contour of special geometric shape, for example a specimen support molded into the receiving tube. The sample support device can be produced particularly easily, since there is no need to

The support prongs may be arranged in the plane of symmetry of the sample support. That is, the sample support may be symmetrically formed.

One bearing projection can form a floating bearing and one bearing projection can form a fixed bearing, or two bearing projections can form a fixed bearing. That is, one of the supporting prongs may be rigidly joined to the receiving tube wall of the receiving tube. The other support projection then rests loosely on or rests on the receiving tube wall of the receiving tube. In this way possible stresses in the sample support which may be due to temperature differences or fabrication can be reliably avoided. Breakage of the sample support due to such stress can be eliminated as much as possible. Alternatively, the two support prongs may be rigidly joined with the receiving tube. This makes it possible to ensure that the sample support is held particularly stably in the receiving tube and positioned precisely.

Alternatively, the sample support may form a reservoir for the analyte. The containment body may be a tank-shaped containment space for the analyte. In this way it can be ensured that the analyte cannot easily fall off the sample support.

The bearing prongs may have a square geometry and each protrude axially at the receptacle. By machining the raw material of the sample support, the shape of such support projections can be easily carved out, which facilitates the fabrication of the sample support. Thus, the supporting prongs project axially in the trough-shaped receptacle of the sample support, thereby increasing the length of the sample support. This increases the electrical contact resistance of the sample support.

Moreover, the cross section of the sample support may be formed in a circular shape. In this case, the support projections may protrude in the radial direction of the sample support. Thus, by forming a gap, the sample support or the trough-shaped receiving space for the analyte can be separated from the receiving tube wall. Uniform and indirect heating of the analyte can thus be ensured. The sample support itself can in principle also be made tubular due to the circular cross-section. Preferably, however, the sample support may also be configured to be arc-shaped with respect to its cross-section.

At least one support peg may be inserted into a receiving gap formed in the receiving tube wall to secure the sample support to the receiving tube wall. Since the receiving gap can be easily produced in the wall of the receiving tube, for example by sawing or milling, the connection between the sample support and the sample support device can be produced particularly cost-effectively. In order to secure the support lugs in the receiving gaps, it is only necessary to establish a fit between the receiving gaps and the support lugs or their parallel sides. Preferably, two support lugs can be inserted into each receiving gap.

In this case, it is advantageous if the support lugs are clamped in the receiving gaps. For example, a press fit between the receiving gap and the support lugs or their parallel sides can easily take place. Since a large force does not act on the sample support, the sample support can be achieved by simply inserting the support projection (singular) or support projections (plurality) into the accommodation gap (singular) or accommodation gap (plurality) and sandwiching them. A tool can be attached to the sample support device.

If the receiving gap is formed at the longitudinal end of the receiving tube, the tubular furnace apparatus can be manufactured even more easily. The receiving gap can be produced particularly easily at the longitudinal ends by sawing or milling.

It is also advantageous if the at least one bearing projection forms a step that rests against the inner surface of the receiving tube. In this way, it can always be ensured that the sample support is arranged at a predetermined distance to the inner surface of the receiving tube. Preferably, the two support prongs each form a step such that the sample support is arranged in the receiving tube parallel to the inner surface. The step may then be formed like a stop.

The sample support may be secured to the containment tube by a thermally decomposable coating. When fabricating the tube furnace apparatus, the sample support can be placed in position within the containment tube. A pyrolytic coating applied to the surface of the tubular furnace apparatus can then join the two parts together with material adhesion.

Furthermore, the tube furnace device can have a through hole through which the bearing extension and the receiving tube can pass. The through-hole may in particular be shaped like an analyte input port which allows particularly easy central placement of the analyte on the sample support.

An analytical instrument according to the invention, in particular an analytical instrument for atomic absorption spectroscopy, comprises a nuclear reactor, which comprises a tubular reactor apparatus according to the invention. Additional embodiments of the analytical instrument emerge from the dependent claims originating from Claim 1 relating to the tubular furnace apparatus.

Preferred embodiments of the present invention will now be described with reference to the accompanying drawings.

1 is a perspective view of a tubular furnace apparatus; FIG. 1 is a side view of a tubular furnace apparatus; FIG. Figure 3 is a cross-sectional view of the tubular furnace along line III-III in Figure 2; 1 is a perspective view of a sample support device of a tubular furnace apparatus; FIG. Fig. 2 is a perspective view of a sample support of the tube furnace apparatus;

1-5 show the tubular furnace apparatus 10 and its components in various views. The tube furnace apparatus 10 is constructed entirely of graphite and is specifically configured for atomic absorption spectroscopy for use in nuclear reactors. The tubular furnace device 10 includes a sample support device 11 for containing an analyte (not shown) and a sample support 12 . The sample support device 11 furthermore has a receiving tube 13 which forms a tubular receiving space 14 in which the sample support 12 is arranged. The sample support device 11 has two bearing extensions 15 on the receiving tube 13 which serve to hold and electrically contact the tube furnace device 10 to a nuclear reactor not shown here. The bearing extension 15 is formed transversely or perpendicularly to the longitudinal axis 16 of the receiving tube 13 . Each bearing extension 15 consists of a bearing 17 and a retaining bridge 18 , which joins the bearing 17 respectively to the receiving tube 13 . For this purpose, the receiving tube 13 is configured to be electrically heatable in the lateral direction via the bearing extension 15 .

The sample support 12 furthermore has only two support lugs 19 , which are formed on opposite longitudinal ends 20 of the sample support 12 . Furthermore, the sample support 12 forms a trough-shaped container 21 for the analyte. The analyte can here be placed centrally on the receiving body 21 via the through hole 22 in the receiving tube 13 and the bearing extension 15 . With respect to the longitudinal axis 16 of the receiving tube 13 , the bearing projection 19 , here formed with a square geometry, extends axially away from the receiving body 21 . At the same time, the support projections 19 protrude radially of the sample support 12 such that the sample support 12 is separated from the inner surface 23 of the receiving tube 13 or from the receiving tube wall 30 via a gap 24 . This allows for indirect, potential-free heating of the analyte in container 21 .

The ends 25 of the bearing prongs 19 are each inserted into a receiving gap 26 formed in the receiving tube 13 . The distal end 25 is formed with a step 27 that allows each support projection 19 to abut the inner surface 23 like a stop 28 . In this way, it can be easily ensured that the gap 24 has the desired uniform spacing to the containment tube wall 30 . Receiving gaps 26 are each formed at the longitudinal ends 29 of the receiving tubes. Receiving gap 26 can be easily formed, for example, by sawing and milling. Also, the desired fit between the receiving gap 26 and the end 25 of each support projection 19 can be easily achieved. The reason is that only the width of the receiving gap 26 and the end 25 should be configured with corresponding tolerances. Also, since a precise positioning of the sample support 12 in the direction of the longitudinal axis 16 can only be obtained by means of the bearing prongs 19 which are already relatively far apart from each other, the sample support 12 and the receiving gap in the radial direction here are 26 can be easily made.

Claims (16)

A tubular furnace apparatus (10) for a nuclear reactor, in particular for atomic absorption spectroscopy, wherein said tubular furnace apparatus comprises a sample support device (11) and a sample support (12), said sample support device having a tubular shape. a storage tube (13) forming a storage space (14), wherein the sample support accommodates an analyte and is disposed in the storage space; and the sample support device is the tubular furnace device. with respect to the longitudinal axis (16) of the containment tube, the containment tube having two bearing extensions (15) serving to hold and electrically contact the Extending in the transverse direction, preferably perpendicular to the longitudinal axis (16), the sample support comprises a support lug (19) by means of which the sample support extends into the receiving tube. a tubular furnace apparatus joined with a containment tube wall (30) of
said sample support has only two of said support projections (19),
said support prongs are respectively formed on opposite longitudinal ends (20) of said sample support ,
The containing tube wall is made of graphite,
Further, the tube-shaped furnace apparatus is characterized in that the sample support is supported by the two support projections on the wall of the storage tube at two points so that it can be placed in the storage tube without an electric potential. The tubular furnace apparatus of claim 1 , wherein
A tube furnace apparatus (10), characterized in that the tube furnace apparatus (10) consists entirely of graphite. In the tubular furnace apparatus according to claim 1 or 2 ,
Tubular furnace apparatus, characterized in that said receiving tube (13) is configured to be electrically heatable in transverse direction via said bearing extension (15). In the tubular furnace apparatus according to any one of claims 1 to 3 ,
said bearing extension (15) consists of a bearing (17) and a retaining bridge (18),
Tubular furnace installation, characterized in that said retaining bridge joins said bearing body with said receiving tube (13). In the tubular furnace apparatus according to any one of claims 1 to 4 ,
A tubular furnace apparatus, characterized in that said support prongs (19) are arranged in a plane of symmetry of said sample support (12). In the tubular furnace apparatus according to any one of claims 1 to 5 ,
one of said support lugs (19) forming a floating bearing and the other of said supporting lugs (19) forming a fixed bearing or two said supporting lugs (19) forming a fixed bearing. A tubular furnace apparatus characterized by: In the tubular furnace apparatus according to any one of claims 1 to 6 ,
A tubular furnace apparatus, characterized in that said sample support (12) forms a vessel-shaped receptacle (21) for the analyte. In the tubular furnace apparatus according to any one of claims 1 to 7 ,
Tubular furnace installation, characterized in that said support lugs (19) have a square geometry and each protrude axially at the receptacle (21). In the tubular furnace apparatus according to any one of claims 1 to 8 ,
The sample support (12) has a circular cross section,
A tubular furnace apparatus, characterized in that said supporting prongs (19) protrude in the radial direction of said sample support. In the tubular furnace apparatus according to any one of claims 1 to 9 ,
Tubular furnace installation, characterized in that at least one support lug (19) is inserted into a receiving gap (26) formed in the receiving tube wall (30). A tubular furnace apparatus according to claim 10 , wherein
A tubular furnace apparatus, characterized in that said supporting prongs (19) are sandwiched in said receiving gaps (26). In the tubular furnace apparatus according to claim 10 or 11 ,
A tubular furnace apparatus, characterized in that said receiving gap (26) is formed at a longitudinal end (29) of said receiving tube (13). In the tubular furnace apparatus according to any one of claims 1-12 ,
Tubular furnace apparatus, characterized in that at least one of said support lugs (19) forms a step (27) that abuts the inner surface (23) of said receiving tube (13). In the tubular furnace apparatus according to any one of claims 1 to 13 ,
A tubular furnace apparatus characterized in that said sample support (12) is fixed to said storage tube (13) by means of a thermally decomposable coating. In the tubular furnace apparatus according to any one of claims 1-14 ,
A tubular furnace arrangement (10) characterized in that it has a through hole (22) passing through said bearing extension (15) and said receiving tube (13). An analytical instrument comprising a nuclear reactor, in particular an analytical instrument for atomic absorption spectroscopy,
An analytical instrument, characterized in that said nuclear reactor comprises a tubular reactor apparatus (10) according to any one of claims 1-15 .

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