Dialysis conductivity probe

Abstract

A dialysis conductivity probe has a stack composed of at least two conductivity measuring cells and at least one spacing holder, wherein the number of conductivity measuring cells is one more than the number of spacing holders. The stack is sealingly tensioned between a first end portion and a second end portion. The conductivity measuring cells and the at least one spacing holder and the end portions each have a central channel section, from which channel sections a continuous measuring channel is assembled. The stack is tensioned between the two end portions by means of tension rods, wherein the tension rods are distributed over the outer circumference of the stack. A respective first end section of each tension rod extends through a respective through-hole of the first end portion, while a respective second end section of each tension rod extends through a respective through-hole of the second end portion. On the end sections of the tension rods there are provided respective recesses or grooves into which recesses or grooves there are inserted respective fixing elements, which fixing elements are tensioned against the outer groove edges of the respective recesses.

Description

Technical Field

[0001] This disclosure relates to a dialysis conductivity probe. This dialysis conductivity probe is used to measure conductivity during the manufacture of the dialysate in a dialysis apparatus. Background Technology

[0002] Dialysis conductivity probes are used for conductivity measurement during the manufacture of dialysate. For this purpose, dialysis conductivity probes with multiple conductivity measurement units are arranged spaced apart from each other by multiple spacing holders and thus stacked. The channel sections of the conductivity measurement units, together with the channel sections of the spacing holders arranged therebetween, constitute the measurement channel. During the manufacture or preparation of dialysate, the measurement channel is traversed by its components, namely permeate and bicarbonate concentrate, or subsequently by the prepared dialysate.

[0003] The conductivity measuring units and the stacked spacing retainers are typically sealed together in a way that prevents the measuring channels from becoming unsealed during transitions between the components. Furthermore, corresponding terminal portions, also referred to as flanges, are provided at both end sections of the stack. Input or output interfaces for the dialysis conductivity probes are also formed on these terminal portions. These terminal portions are also typically sealed and tensioned onto the first or last conductivity measuring unit.

[0004] Existing technology

[0005] As is known in the prior art, four anchors or rods are evenly distributed around the circumference of a stack, which tension the stack and corresponding pressure springs. A threaded connection is used to set the spring force or tension. For this purpose, the rods have metric threads on both sides and are screwed into the lower end portion (lower flange) on one side. In the lower end portion, no threads are pre-formed, and the threaded rod must self-form threads in the end portion. However, metric threads are not designed for this type of threaded connection. In the upper region, where pressure springs are also arranged, nuts are screwed onto the corresponding threaded rods. There, the nuts often jam, damaging the threaded rods. This causes fluctuations during tightening and requires repeated correction. Therefore, the sealing tensioning process via threaded connection is unreliable. Furthermore, tightening the nuts by counting rotations is too time-consuming. Utility Model Content

[0006] The objective of this disclosure is to provide a dialysis conductivity probe whose production, particularly the final tight compression of its stacked components, is simplified and the process is more reliable.

[0007] This task is solved by the present invention. Advantageous embodiments and improvements are described below.

[0008] The dialysis conductivity probe according to this disclosure has a stack, which is assembled (stacked) from at least two conductivity measuring units and at least one spacing holder in an alternating sequence, i.e., in the sequence of conductivity measuring unit, spacing holder, conductivity measuring unit, additional spacing holder if necessary, additional conductivity measuring unit, and so on. Preferably, multiple conductivity measuring units and multiple spacing holders are provided. The number of conductivity measuring units is particularly greater than the number of spacing holders / multiple spacing holders. The stack is tensioned between a first terminal portion and a second terminal portion. The terminal portion may also be referred to as a flange. The conductivity measuring unit, at least one spacing holder, and the two terminal portions each have a central channel segment from which a continuous measuring channel of the dialysis conductivity (measuring) probe is assembled. Thus, the components are sealed against each other. For this purpose, the stack is tensioned between the two terminal portions by means of at least three, preferably four, tie rods. The tie rods are preferably evenly distributed on the outer periphery of the stack. Each pull rod has a first end section extending through a corresponding through-hole in a first terminal portion, and a corresponding second end section extending through a corresponding through-hole in a second terminal portion. According to this disclosure, a corresponding, preferably circumferential, first groove or slot is provided on the first end section of each pull rod, into which a corresponding first fixing element is inserted, tensioned from the stack to the outer edge of the corresponding first groove. The outer edge is understood as the further groove edge of the two groove edges of the groove or slot, further away from the stack. Similarly, each pull rod has a corresponding, preferably circumferential, second groove or slot provided on the second end section, into which a corresponding second fixing element is inserted, tensioned from the stack to the outer edge of the corresponding second groove. Here, the outer edge is also understood as the further groove edge of the two groove edges of the groove or slot, further away from the stack. This simplifies the process and reliably achieves a sealing compression between the stacked components and the two terminal portions. In other words, according to this disclosure, a corresponding first groove or a corresponding first slot is provided on the first end section of each pull rod, and a corresponding first fixing element is inserted into the first groove or the first slot, the first fixing element being tensioned on the outer edge of the corresponding first groove. Similarly, a corresponding second groove or a corresponding second slot is provided on the second end section of each pull rod, and a corresponding second fixing element is inserted into the second groove or the second slot, the second fixing element being tensioned on the outer edge of the corresponding second groove. In particular, according to this disclosure, it is not necessary to cut threads on the pull rod. This advantageously eliminates the need for screws to be screwed into the plastic of the second end portion. Since there are no threads on the pull rod, the nut's jamming on the threads of the first end section of the pull rod is avoided.The distance between the two grooves or slots of each pull rod, especially the distance between the edges of the two outer grooves, can be precisely determined and precisely matched with the temperature range of the dialysis conductivity probe to be operated.

[0009] Preferably, four tie rods are evenly distributed on the outer periphery of the stack. Two tie rods, diagonally opposite each other, may not contact the outer periphery of the stacked components (conductivity measuring unit and spacing retainer), while the other two diagonally opposite tie rods are embedded in the holding and / or guiding device of the spacing retainer, which extends radially outward toward the two associated tie rods. However, according to this disclosure, other numbers of tie rods, such as three, five, six, seven, etc., are also conceivable, and it is also conceivable that more than two tie rods, such as three, four, five, six, seven, etc., are embedded in the holding and / or guiding device of the spacing retainer.

[0010] The retaining element can be closed on each side or around the entire circumference and axially fitted along the longitudinal axis of the pull rod until it reaches the groove. In prior art threaded connections, it is difficult to precisely position the nut on the corresponding thread in the first end section of the pull rod. Relatedly, the groove or slot according to this disclosure, and particularly the non-elastic retaining element, presents a significant advantage. Less elasticity allows for laterally open retaining elements, which are fitted onto the groove in a radial direction relative to the longitudinal axis of the pull rod. That is, it has been shown, in particular, according to this disclosure, that laterally open retaining elements fitted into the groove or slot in a radial direction relative to the longitudinal axis of the pull rod are advantageous compared to retaining elements that are closed around the entire circumference and axially fitted along the longitudinal axis of the pull rod until they reach the groove / slot. Here, a retaining disc for the shaft (shaft retaining disc) or SEEGER ring proves to be a preferred retaining element. A particularly preferred retaining element here is a retaining disc for the shaft. This type of safety disc, due to its structure, can be radially mounted on the tie rod by simply pressing it into a groove or slot without the need for special tools. According to this disclosure, this safety disc is suitable for relatively low axial loads.

[0011] According to the preferred improvement, when the edge of the outer groove is perpendicular to the longitudinal axis of the associated tie rod, the stack and the two end portions are optimally and precisely tensioned.

[0012] To create stacked elasticity, elastic sealing rings can be used, which are arranged between the conductivity measuring unit and the adjacent spacing holder, and between the conductivity measuring unit and the adjacent terminal section.

[0013] To generate the stacked elasticity, it is preferable to arrange a corresponding compression spring on the first end section of the pull rod, the compression spring being tensioned between the corresponding first fixing element and the first end portion.

[0014] Between the compression spring and the first terminal portion, a single-piece or multi-piece first force balancing device may be required to balance the spring force. On the first fixing element, on the inner side, i.e., on the stacking side or on the compression spring side, a single-piece or multi-piece second force balancing device may be required. On the second fixing element, on the inner side, i.e., on the stacking side, a single-piece or multi-piece third force balancing device may be required.

[0015] Multi-piece force balancing devices (multiple force balancing devices) can be formed from inexpensive shims. Here, the number of shims in each force balancing device corresponds specifically to the number of tie rods.

[0016] The force balancing device can be implemented as a single piece and formed by corresponding pads with through holes. The number of through holes in each pad corresponds specifically to the number of tie rods. This simplifies installation. The pads installed first provide installation assistance in the form of positioning aids.

[0017] In the improved design with four tie rods, the pad is implemented in a substantially quadrilateral shape, particularly a square shape, wherein a through hole for one of the tie rods is provided in each corner.

[0018] If the pad has at least one external tab or external lug extending radially away from the longitudinal axis of the adjacent tie rod, then the pad can be detected by a grating and its presence can be guaranteed.

[0019] Preferably, the pad has eight tabs or lugs, with two tabs or lugs at each corner of the pad, and the tabs or lugs are preferably arranged approximately perpendicular to each other. This provides maximum flexibility when installing the pad, as each pad can be positioned in eight different locations, that is, pushed onto four levers. Attached Figure Description

[0020] Figure 1 The dialysis conductivity probe according to the first embodiment of this disclosure is shown in a cross-sectional view. Figure 2 It is based on another sectional view. Figure 1 The dialysis conductivity probe of the first embodiment; Figure 3 The dialysis conductivity probe according to the second embodiment in a perspective view; and Figure 4 The dialysis conductivity probe according to the third embodiment is shown in a three-dimensional view.

[0021] Wherein: 1- (Conductivity measuring unit 2) channel section; 2-Conductivity measuring unit; 3- (Gap holder 4) channel section; 4- (Shorter) gap holder; 5-Bent channel section; 6a-First terminal portion; 6b-Second terminal portion; 8-Sealing ring; 10- (Shorter) pull rod; 12a-First end section; 12b-Second end section; 14a-Through hole of the first terminal portion; 14b-Second... Through hole in the terminal section; 16a-first groove; 16b-second groove; 17a-edge of the first outer groove; 17b-edge of the second outer groove; 18a-first fixing element; 18b-second fixing element; 20-compression spring; 22a-waist pad; 22b-waist pad; 22c-waist pad; 104-(longer) gap retainer; 110-(longer) tie rod; 222a-pad; 222b-pad; 222c-pad. Detailed Implementation

[0022] Three embodiments of this disclosure are described below with reference to the accompanying drawings.

[0023] Figure 1 The dialysis conductivity probe according to a first embodiment of the present disclosure is located in a cross-section along a central measurement channel, which is assembled from channel segments 1 of conductivity measurement units 2, channel segments 3 of spacing holders 4, and curved channel segments 5 of terminal portions 6a, 6b. More precisely, the dialysis conductivity probe has a stack, which in the illustrated first embodiment consists of three conductivity measurement units 2 and two spacing holders 4 disposed therebetween. Figure 1 The upper and lower portions of the measuring channel are limited by corresponding terminal portions 6a and 6b, which may also be referred to as flanges or connectors, as these two portions provide an inlet to the measuring channel and an outlet to the outside of the measuring channel.

[0024] The conductivity measuring unit 2, also referred to as an electrode, has a conductive inner sleeve forming the corresponding channel segment 1 and a corresponding non-conductive body. The spacing holder 4 is also non-conductive and has two contact surfaces for adjacent conductivity measuring units 2. The conductivity measuring unit 2 has a piston-type structure from which electrical contact heads (not shown) extend radially.

[0025] A series of sealing rings 8 are provided between the components of the dialysis conductivity probe (conductivity measurement unit 2, spacing holder 4, and terminal portions 6a, 6b), which are pressed together in a sealing manner. For this purpose, four pull rods 10, oriented parallel to the measurement channel, extend on the outer periphery of the stack and through the terminal portions 6a, 6b. Only two pull rods 10 are visible in this cross-sectional view, as they are substantially obscured.

[0026] Figure 2It is based on the sectional view Figure 1 The first embodiment of the dialysis conductivity probe, wherein the cross-section is located in two of the four pull rods 10 in total. The first ( Figure 2 The upper end section 12a of each pull rod 10 extends through a corresponding through hole 14a in the first end portion 6a. Figure 2 The lower end section 12b extends through the corresponding through hole 14b of the second terminal portion 6b.

[0027] A circumferential groove 16a, 16b is inserted into each of the two end sections 12a, 12b of each pull rod 10, and a corresponding fixing element 18a, 18b, configured as a safety ring open on one side or a safety disc open on one side, is pushed into the groove.

[0028] In each of the 10 (in Figure 2 A corresponding pressure spring 20 is arranged between the first fixing element 18a and the first terminal portion 6a in the upper part of the structure. Each pressure spring 20 is supported on the corresponding first fixing element 18a by a washer 22a on one hand and on the first terminal portion 6a by another washer 22c on the other hand.

[0029] In each of the 10 (in Figure 2 A gasket 22b is arranged between the second fixing element 18b and the second terminal part 6b in the lower part of the middle.

[0030] The distance between the two grooves 16a, 16b or slots of each pull rod 10, especially the distance between the two outer groove edges 17a, 17b (with the corresponding safety rings or corresponding safety discs 18a, 18b pressing against the two outer groove edges), is precisely selected and manufactured and precisely coordinated with the required temperature range in which the dialysis conductivity probe should operate.

[0031] Figure 3 This is a dialysis conductivity probe according to the second embodiment, shown in a three-dimensional view. (Compared to...) Figure 1 and Figure 2 The difference in the first embodiment is that the four pull rods 110 are extended, thereby allowing for the arrangement of more conductivity measurement units 2, more spacing holders 4, and larger spacing holders 104.

[0032] Therefore, Figure 1 and 2 The conductivity probe is used as the so-called BIC-LF probe, while Figure 3 The conductivity probe is used as a so-called END-LF probe.

[0033] According to Figure 3In the dialysis conductivity probe, the tensioning technology of the fixing elements 18a, 18b, which are constructed as safety rings or safety discs, and the force balancing device formed by four gaskets 22a, 22b respectively, corresponds to... Figure 1 and 2 The tensioning technique of the first embodiment.

[0034] Figure 4 This is a dialysis conductivity probe according to the third embodiment, shown in a three-dimensional view. (Compared to...) Figure 1 and 2 The difference in the first embodiment is that, instead of being formed by four pads respectively, each of the three force balancing devices is formed by pads 222a, 222b, and 222c. Pads 222a, 222b, and 222c are substantially square, wherein a through hole for one of the pull rods 10 is provided in each corner.

[0035] Two tabs 224 or lugs extend from each corner of the pads 222a, 222b, 222c at an angle of 90 degrees to each other away from the edge. Here, the two tabs 224 or lugs are able to extend radially away from the through-holes arranged in the respective corners and thus radially away from the pull rods 10 arranged in the respective corners. One of the total eight tabs 224 is detected during installation inspection by a grating (not shown) and thus the presence of the respective pads 222a, 222b, 222c is checked.

[0036] With a total of eight tabs 224, maximum freedom of choice is achieved during installation, as a total of eight correct installation positions for each pad 222a, 222b, 222c are possible.

[0037] exist Figure 4 The dialysis conductivity probe incorporates a tensioning technique with grooves 16a and 16b and fixing elements 18a and 18b configured as safety rings or safety discs. Additionally, it features a stack consisting of three conductivity measurement units 2 and two spacing holders 4 positioned between them. Figure 1 and 2 The tensioning technique of the first embodiment.

[0038] All the four pressure springs 20 and the two terminal portions 6a, 6b shown in the embodiments are identical.

Claims

1. A dialysis conductivity probe having a stack hermetically composed of at least two conductivity measurement units (2) and at least one spacing holder (4), wherein, The number of conductivity measurement units (2) is one more than the number of one spacing holder (4) / multiple spacing holders (4). The stack is sealed and tensioned between the first terminal portion (6a) and the second terminal portion (6b). The conductivity measurement unit (2), the at least one spacing holder (4), and the terminal portions (6a, 6b) each have channel segments (1, 3, 5), from which a continuous measurement channel of the dialysis conductivity measurement probe is assembled. The stack is tensioned between the two end portions (6a, 6b) by means of at least three tie rods (10; 110). The pull rods (10; 110) are distributed on the outer periphery of the stack, wherein a first end segment (12a) of each pull rod (10; 110) extends through a corresponding through-hole of the first terminal portion (6a), and wherein a second end segment (12b) of each pull rod (10; 110) extends through a corresponding through-hole of the second terminal portion (6b). Its features are, Each tie rod (10; 110) has a corresponding first groove (16a) or a corresponding first slot on its first end section (12a). A corresponding first fixing element (18a) is inserted into the first groove or the first slot. The first fixing element is tensioned on the outer edge (17a) of the corresponding first groove (16a). A corresponding second groove (16b) or a corresponding second slot is provided on the second end section (12b) of each pull rod (10; 110), and a corresponding second fixing element (18b) is inserted into the second groove or the second slot, and the second fixing element is tensioned on the outer groove edge (17b) of the corresponding second groove (16b).

2. The conductivity probe of claim 1, wherein, The fixing elements (18a, 18b) are laterally open and radially fitted onto the grooves (16a, 16b) or the slots along the longitudinal axis of the tie rods (10; 110).

3. The conductivity probe according to claim 1 or 2, characterized in that, The outer groove edges (17a, 17b) are perpendicular to the longitudinal axis of the associated tie rods (10; 110).

4. The conductivity probe according to claim 1 or 2, characterized in that, Elastic sealing rings (8) are arranged between the conductivity measuring unit (2) and the adjacent spacing holder (4) and between the conductivity measuring unit (2) and the adjacent terminal portions (6a, 6b).

5. The conductivity probe of claim 1 or 2, wherein, A pressure spring (20) is arranged on the first end section (12a) of the pull rod (10; 110), the pressure spring being tensioned between the corresponding first fixing element (18a) and the first end portion (6a).

6. The conductivity probe of claim 5, wherein, A force balancing device (22c; 222c) for the spring force is arranged between the pressure spring (20) and the first terminal portion (6a).

7. The conductivity probe of claim 1 or 2, wherein, A first force balancing device is attached to the first fixing element (18a) on the stacking side or the pressure spring side and / or a second force balancing device is attached to the second fixing element (18b) on the stacking side.

8. The conductivity probe according to claim 6, characterized in that, The force balancing device is formed by pads (22a; 22b; 22c).

9. The conductivity probe according to claim 6, characterized in that, The force balancing device is formed by corresponding pads (222a; 222b; 222c) with through holes.

10. The conductivity probe according to claim 9, characterized in that, Four pull rods (10) are provided, and the pads (222a; 222b; 222c) are substantially quadrilateral, wherein a through hole for one of the pull rods (10) is provided in each corner.

11. The conductivity probe according to claim 9 or 10, characterized in that, The pad (222a; 222b; 222c) has at least one external tab (224) or external lug that extends away from the longitudinal axis of one of the pull rods (10).

12. The conductivity probe of claim 10, wherein, The plate is provided with eight tabs or lugs, wherein two tabs (224) or lugs are provided at each corner of the pad (222a; 222b; 222c), and the tabs or lugs are arranged perpendicular to each other.

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