Admixture piece and housing element for a mixing device

Abstract

A tubular admixture piece for receiving in a mixing device for controlled metering in of an adjuvant into a pumpable mixture has at least one sealing element for producing an at least partially fluid-tight connection between the admixture piece and the mixing device wherein the at least one sealing element is designed as an axial seal with respect to a longitudinal axis of the tubular admixture piece. A housing element of a mixing device has at least a sealing support for axial sealing of the admixture piece, and is also configured to exert a force that acts on the admixture piece in the axial direction and/or longitudinal direction of the through-flow opening, such that the axial seal of an admixture piece received at least partially in the through-flow opening can be pressed against the sealing support by the force.

Claims

1. Tubular admixture piece for receiving in a mixing device for controlled metering of an additive into a pumpable mixture, wherein the admixture piece has a mixing section extending through the admixture piece for conveying the pumpable mixture, and, in a wall of the admixture piece, at least one opening leading into the mixing section is provided, for the purpose of introducing the additive into the mixing section, and wherein, on the admixture piece, at least one sealing element is present for establishing an at least partially fluid-tight connection between the admixture piece and the mixing device, the at least one sealing element being designed in reference to a longitudinal axis of the tubular admixture piece as an axial seal, wherein the axial seal is designed as a ring-shaped sealing lip, wherein the axial seal is arranged on a front side of a flange formed on the admixture piece, wherein the axial seal arranged on the front side of the flange is arranged spaced at least partially away from the wall of the admixture piece, so that a groove is present between the axial seal and the wall, wherein the groove comprises a concave curved delimitation surface, wherein at least one additional sealing element is present, which is spaced in the direction of the longitudinal axis of the tubular admixture piece away from at least one sealing element, and wherein the additional sealing element is also designed as an axial seal and as a ring-shaped sealing lip, wherein the at least one additional sealing element is oriented closer to the mixing section, in a radial direction of the tubular admixture piece, than the at least one sealing element is to the mixing section, and wherein both the at least one sealing element and the at least one additional sealing element are oriented so as to point in a same direction.

2. Tubular admixture piece according to claim 1, wherein a wedge angle of the sealing lip measures 10 - 80.

3. Admixture piece according to claim 1, wherein a maximum extent of the additional sealing element in a direction perpendicular to the longitudinal axis of the tubular admixture piece is smaller than a maximum extent of the at least one sealing element.

4. Tubular admixture piece according to claim 1, wherein at least one sealing element is connected by substance bonding to the admixture piece.

5. Tubular admixture piece according to claim 1, wherein the admixture piece, in the area of the at least one sealing element, is designed as an axial seal.

6. Tubular admixture piece according to claim 1, wherein the at least one sealing element forms an integral component of the admixture piece.

7. Tubular admixture piece according to claim 1, wherein the at least one sealing element, at least in the area of the at least one sealing element, consists of the same material as the admixture piece.

8. Tubular admixture piece according to claim 7, wherein the admixture piece is manufactured, at least in the area of the at least one sealing element, from a plastic having a Shore A hardness of 50-120.

9. Tubular admixture piece according to claim 1, wherein the admixture piece consists of a single-piece cast body and a reinforcing element embedded at least partially therein, wherein the cast body consists of a plastic.

10. Tubular admixture piece according to claim 1, wherein a first surface of the axial seal extending away from the groove extends to a free end of the sealing lip where the first surface meets a second surface of the free end of the sealing lip, and a wedge angle between the first surface and the second surface is from 10 to 80.

11. Housing element of a mixing device for the controlled injection of an additive into a pumpable mixture, wherein the housing element comprises a base body with a through-flow opening, and the through-flow opening is designed for receiving at least partially an admixture piece according to claim 1, wherein at least one sealing supportarranged on the housing elementis present for the at least one sealing element of the admixture piece designed as an axial seal, and means are present for exerting a force acting in the axial direction and/or longitudinal direction of the through-flow opening onto the admixture piece, so that the axial seal of an admixture piece received at least partially in the through-flow opening can be pressed by the means for exerting force against the sealing support.

12. Housing element according to claim 11, wherein, as means for exerting a force onto the admixture piece, a union nut that can be screwed to the base body is present.

13. Housing element according to claim 11, wherein additionally an additional sealing support arranged in the base body is present for an additional sealing element present on the admixture piece and designed as an axial seal.

14. Housing element according to claim 13, wherein the at least one sealing support is configured as an inner cone surface and/or the additional sealing support is configured as an outer cone surface.

15. Apparatus set, comprising a tubular admixture piece and a housing element according to claim 11, wherein the admixture piece has a mixing section extending through the admixture piece for conveying the pumpable mixture, and, in a wall of the admixture piece, at least one opening leading into the mixing section is provided, for the purpose of introducing an additive into the mixing section, and wherein, on the admixture piece, at least one sealing element is present for establishing an at least partially fluid-tight connection between the admixture piece and the mixing device, the at least one sealing element being designed in reference to a longitudinal axis of the tubular admixture piece as an axial seal, wherein the axial seal is designed as a ring-shaped sealing lip, wherein the axial seal is arranged on a front side of a flange formed on the admixture piece, and wherein the axial seal arranged on the front side of the flange is arranged spaced at least partially away from the wall of the admixture piece, so that a groove is present between the axial seal and the wall, wherein the groove comprises a concave curved delimitation surface.

16. A method of metering an additive into an pumpable mixture, using a tubular admixture piece for receiving in a mixing device for controlled metering of an additive into a pumpable mixture, wherein the admixture piece has a mixing section extending through the admixture piece for conveying the pumpable mixture, and, in a wall of the admixture piece, at least one opening leading into the mixing section is provided, for the purpose of introducing the additive into the mixing section, and wherein, on the admixture piece, at least one sealing element is present for establishing an at least partially fluid-tight connection between the admixture piece and the mixing device, the at least one sealing element being designed in reference to a longitudinal axis of the tubular admixture piece as an axial seal, wherein the axial seal is designed as a ring-shaped sealing lip, wherein the axial seal is arranged on a front side of a flange formed on the admixture piece, wherein the axial seal arranged on the front side of the flange is arranged spaced at least partially away from the wall of the admixture piece, so that a groove is present between the axial seal and the wall, wherein the groove comprises a concave curved delimitation surface, wherein at least one additional sealing element is present, which is spaced in the direction of the longitudinal axis of the tubular admixture piece away from at least one sealing element, and wherein the additional sealing element is also designed as an axial seal and as a ring-shaped sealing lip, wherein the at least one additional sealing element is oriented closer to the mixing section, in a radial direction of the tubular admixture piece, than the at least one sealing element is to the mixing section, and wherein both the at least one sealing element and the at least one additional sealing element are oriented so as to point in a same direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings which are used to explain the embodiment examples:

(2) FIG. 1 shows a hollow cylindrical admixture piece with two sealing lips designed as axial seals in a perspective view;

(3) FIG. 2 shows a longitudinal section along line A-B through the admixture piece of FIG. 1;

(4) FIG. 3 shows a housing element with two truncated cone surfaces as sealing supports and a union nut as means for the exertion of a force acting in the axial direction and/or longitudinal direction of the admixture piece;

(5) FIG. 4 shows the housing element of FIG. 3, fitted with the admixture piece of FIGS. 1-2, which is connected additionally to a conveyance tube and to a nozzle for spraying concrete; and

(6) FIG. 5 shows a variant of the hollow cylindrical admixture piece of FIG. 1 with a cast-in, ring-shaped reinforcing element in the area between the two sealing lips in a longitudinal section.

(7) Identical parts basically bear identical reference numerals in the figures.

(8) Ways To Carry Out The Invention

(9) Admixture Piece

(10) In FIGS. 1 and 2, a tubular admixture piece 100 according to the invention is represented. The admixture piece 100 comprises a hollow cylindrical base body 102 with a circular cylindrical through-flow passage 101 extending along the longitudinal axis 101.2, which extends completely through the base body 102, and is used as mixing section or conveyance line for a pumpable mixture.

(11) At one end, on the base body 102, a circumferential flange 105 is arranged. On the front-side surface of the flange 105, which faces the other end of the base body 102, a ring-shaped circumferential first sealing lip 110 designed so it is rotationally symmetrical with respect to the longitudinal axis 101.2 is arranged as a sealing element. The first sealing lip 110 is designed as an axial seal, and it has a wedge-shaped tapering cross section in a direction away from the front side of the flange 105. A wedge angle 111.1 of the first sealing lip 110 is, for example, approximately 30. In the area of the outer circumferential surface, the sealing lip transitions seamlessly into the outer lateral surface of the flange 105.

(12) An area of the free end 111 of the first sealing lip 110 or an area of the wedge tip is convexly curved, and forms a sealing edge of the sealing lip 110. In addition, in the radial direction, the sealing lip 110 is spaced away from the base body 102, so that a first circumferential groove 112 with a concavely curved delimitation surface is present between the wall of the base body 102 and the sealing lip 110.

(13) In the area of the other end, the tubular admixture piece 100 has a step-shaped tapering or a radially pinched in tapering, on which an additional sealing element in the form of an additional circumferential sealing lip 120 is arranged. Like the first sealing lip 110, the second sealing lip 120 is also designed as an axial seal, it has a wedge-shaped tapering cross section, and it is rotationally symmetrical with respect to the longitudinal axis 101.2. With the exception of the reduced diameter in the radial direction, the additional sealing lip 120 is designed and oriented substantially the same as the first sealing lip 110. Accordingly, the second sealing lip 120 also has a wedge angle 121.1 of for example, approximately 30, and an area of the free end 121 of the additional sealing lip 120 forms a convexly curved sealing edge. Moreover, the additional sealing lip 120 is spaced in the radial direction away from the wall of the base body 102, so that an additional circumferential groove 121 with a concavely curved delimitation is present between the wall of the base body 102 and the additional sealing lip 120. Here, the additional sealing lip 120 transitions seamlessly into the wall of the hollow cylindrical base body 102.

(14) In addition, approximately in the middle between the two ends of the tubular admixture piece 100 and between the two sealing lips 110, 120, for example, six evenly spaced openings 103 leading in the radial direction into the circular cylindrical through-flow 101 are introduced into the wall of the hollow cylindrical base body 102. Said openings are used to introduce an additive into the circular cylindrical through-flow passage 101 provided as a mixing section. For example, it is also possible to provide 4 or 8 openings, which can also be at an angle with respect to the longitudinal axis.

(15) A total length of the admixture piece 100, measured along the longitudinal axis 101.2, measures, for example, approximately 125 mm. An outer diameter 110.1 of the first sealing lip 110, measured in a direction perpendicular to the longitudinal axis 101.2 of the tubular admixture piece 100, measures, for example, approximately 100 mm, whereas an outer diameter 120.1 of the additional sealing lip 120 is, for example, approximately 87 mm. Thus, the outer diameter 120.1 of the additional sealing element is approximately 13% smaller than the outer diameter of the first sealing element. An inner diameter 101.1 of the admixture piece 100 is approximately 60 mm, for example.

(16) The tubular admixture piece 100 is manufactured in particular entirely in the form of a single piece of plastic. An example of a suitable plastic is polyurethane having a Shore A hardness of approximately 50-120, for example, Shore A 75 or Shore A 90.

(17) Housing Element

(18) FIG. 3 shows a longitudinal section through a housing element 200 according to the invention, which comprises a tubular base body 225 with a central through-flow opening 201. The through-flow opening 201 here extends from a first end 230 to a second end 240 along a longitudinal center axis 201.1 completely through the base body 225. The through-flow opening 201 is here divided into several areas with different inner diameters, wherein all the areas are designed to be rotationally symmetrical with respect to the longitudinal center axis 201.1.

(19) From the first end 230 of the base body 225 on, the through-flow opening 201 tapers conically. In other words, the section beginning at the first end 230 of the through-flow opening 201 is designed as a lateral surface of a truncated cone or inner cone surface 210. The inner cone surface 210 is used here as a sealing support for an axial seal of an admixture piece received in the base body 225. This is, for example, an admixture piece 100 as shown in FIGS. 1-2. An opening angle of the inner cone surface 210 measures, for example, approximately 90 (measured 45 from the longitudinal center axis).

(20) The inner cone surface 210 is followed by a first hollow cylindrical section 202 with constant inner diameter, which transitions via a conical intermediate area 203 into a second hollow cylindrical section 204 with increased inner diameter.

(21) The second hollow cylindrical section 204 subsequently leads into a third hollow cylindrical section 205. The transition between the second and the third hollow cylindrical sections is here designed step-shaped as a lateral surface of a truncated cone or outer cone surface 220, which is used as an additional sealing support for an additional axial seal of an admixture piece received in the base body 225. An opening angle of the outer cone surface 220 measures, for example, approximately 200 (measured 100 from the longitudinal axis).

(22) The third hollow cylindrical section 205 finally transitions in a step-shaped manner into a connection area 206 with an enlarged diameter. The connection area 206 is designed, for example, for the connection of a conveyance line or of a conveyance tube.

(23) In addition, two radial bores 213a, 213b lead into the area of the second hollow cylindrical section 204, from diametrically opposite directions, as feed lines for introducing an additive into the through-flow opening 201. One bore 213a is closed, for example, by means of a closure cap 402, while a tube line or a pipe 401 is connected to the other bore 213b via a curved connection piece 400. Depending on the application, it is also possible for the two bores 213a, 213b to be provided with a connection piece 400.

(24) An inner diameter 202.1 of the first hollow cylindrical section 202, which corresponds to a minimum diameter of the inner cone surface 210, is here greater than an inner diameter 205.1 of the third hollow cylindrical section 205, which corresponds to the minimum diameter of the outer cone surface 220. In other words, the minimum diameter of the additional sealing support (outer cone surface 220) is thus smaller than the minimum diameter of the first sealing support (inner cone surface 210) in the housing element 200.

(25) Moreover, in the area of the first end 230, an outer thread 250 is provided in the base body 225. A union nut 300 is screwed onto the outer thread 250.

(26) The union nut 300 has a first hollow cylindrical end with an inner thread 301 extending in the direction of the longitudinal axis. At the other end of the union nut, a circular cylindrical opening 302 is present, which tapers in a step-shaped manner across from the first end. As a result, in the interior of the union nut 300, a plate-shaped front surface 303 adjacent to the opening 302 is present, which is provided as a contact surface for an admixture piece and/or additional tubular elements. A diameter 302.1 of the opening is here smaller than a diameter of the inner thread 301.

(27) By means of a screwing motion of the union nut 300 on the outer thread 250 of the base body 225, the union nut can be moved in the axial direction or in the direction of the longitudinal axis 201.1 toward the base body 225. An element arranged behind the opening 302 of the union nut 300 and bearing against the front surface 303, for example, an admixture piece 100 as shown in FIGS. 1-2, can thus be pressed against the housing element. As a result, the union nut can be used as a means for exerting a force acting in the axial direction or in the direction of the longitudinal axis 201.1.

(28) The base body 225 and the union nut 300 are advantageously manufactured from plastic, each forming a single piece. As plastic, POM-C for example is suitable,

(29) Apparatus Set

(30) The admixture piece 100 and the housing element 200 together form an apparatus set. A spacing of the two sealing edges 111, 121 on the admixture piece 100 here corresponds substantially to a spacing of the two sealing supports 210, 220 on the housing element 200. An outer diameter of the admixture piece 100, between the two sealing lips 110, 120, is moreover smaller than the inner diameter in the area of the first two hollow cylindrical sections 202, 204 and the conical intermediate area 203. As a result, the admixture piece 100 can be received in the radial direction with play in the through-flow opening 201.

(31) FIG. 4 shows an arrangement comprising the housing element 200 of FIG. 3 with the admixture piece 100 of FIGS. 1-2 received therein, in a longitudinal cross section. This arrangement corresponds to a mixing device for the controlled metering of an additive into a pumpable hydraulic setting mixture, in particular a wet, earth-moist or dry spray concrete composition.

(32) The first sealing lip 110 of the admixture piece 100 bears with its free end 111 or with the sealing edge against the inner cone surface 210 of the base body 225. Similarly, the additional sealing lip 120 of the admixture piece 100 bears with its free end 121 or with the sealing edge against the outer cone surface 220 of the base body 225. Here, the area of the flange 105 projects in the axial direction beyond the first end 230 of the base body 225 into the inner area of the union nut 300. In addition, an inlet-side flange 601 of a nozzle 600 for spraying concrete is arranged between the flange-side end of the admixture piece 100 and the front surface 303 of the union nut 300. The outer diameter of the inlet-side flange 601 of the nozzle 600 for spraying concrete is here greater than the diameter of the opening 302 of the union nut 300. By tightening the union nut 300, the inlet-side flange 601 of the nozzle 600 for spraying concrete is pushed against the flange-side end of the admixture piece 100, as a result of which the two sealing lips 110, 120 are pressed in the axial direction against the respective support surfaces 210, 220. As a result, fluid-tight connections are present between the sealing lips 110, 120 and the associated support surfaces 210, 220. A fluid which, through the connection piece 400, reaches the first two hollow cylindrical sections 202, 204 and the conical intermediate area 203, for example, an additive for a spray concrete composition, can thus escape only through the openings 103 in the admixture piece 100, as a result of which a controlled admixing of the fluid into the mixing section 101 of the admixture piece 100 or into a pumpable mixture conveyed therein is made possible.

(33) In the connection area 206 of the housing element 200, an open end of a conveyance pipe or of a conveyance tube 500, provided with a coupling device, is additionally connected in a known manner. Through the conveyance pipe or the conveyance tube 500, a pumpable mixture, for example, a spray concrete composition, can be conveyed into the admixture piece 100. An inner diameter of the conveyance pipe or of the conveyance tube 500 corresponds substantially to the inner diameter 101.1 of the tubular admixture piece 100.

(34) FIG. 5 shows an additional tubular admixture piece 800 according to the invention in cross section. This piece is substantially identical in design to the admixture piece 100 of FIGS. 1 and 2, but, in addition, in an area between the two sealing elements 810, 820, it comprises a reinforcing element 850. The reinforcing element 850 is designed as a steel ring and it is completely embedded or cast in the wall of the tubular admixture piece 800. A length of the reinforcing element in the axial direction measures, for example, approximately 17% of the total length of the admixture piece 800 in the axial direction.

(35) Installation/Removal Procedures

(36) The installation of the arrangement of FIG. 4 is possible in a simple manner. In a first step, the union nut 300, which has been removed from the base body 225, is slid over the nozzle 600 for spraying concrete until the inlet-side flange 601 bears against the plate-shaped front surface 303 of the union nut. Subsequently, or at the same time, the tubular admixture piece 100 is pushed from the first end 230 into the through-flow opening 201 of the housing element 200, until the two sealing lips 110, 120 bear against the respective sealing supports 210, 220 in the base body 225. Subsequently, the union nut 300 is screwed, together with the nozzle 600 for spraying concrete, onto the outer thread 250 of the base body 225 and tightened. As the union nut 300 is screwed on, the two sealing lips 110, 120 are automatically pressed against the associated sealing supports 210, 220. The conveyance pipe or the conveyance tube 500 can be connected independently of the remaining components at any desired time.

(37) In order to replace or remove the admixture piece 100, the union nut 300 is detached completely and removed from the base body 225. Subsequently, the admixture piece can be gripped at the flange-side end and pulled out of the through-flow opening without exertion of appreciable force.

(38) The installation and removal procedures also work similarly with the tubular admixture piece 800 of FIG. 5.

(39) Test Trials

(40) In order to test the pressure resistance of the housing according to the invention, the housing element 200 (FIG. 3) made of POM-C was fitted with an admixture piece 100 (FIGS. 1-2) made of polyurethane having a Shore A hardness of approximately 90. The connection area 206 as well as the opening 302 of the union nut 300 were each closed here in a fluid-tight manner with a blank flange. Subsequently, through the connection piece 400, pressurized water was supplied and the water pressure was increased continuously. In the process, the resulting pressure resistances of the arrangement were here up to 50-60 bar before a pressure release took place as a result of expansion of the material of the union nut 300. Neither the union nut 300 nor the connection area 206 was damaged in the process, so that it was possible to run the tests repeatedly. This is advantageous particularly with a view to occupational safety, because there is no risk of the housing element or the admixture piece rupturing and being torn apart, which could result in injuries to persons.

(41) In order to test the pressure resistance of the sealing lips 110 and 120, the bores 103 were additionally sealed off, and, in the case of one blank flange, a bore to the opening 101 was produced. Thus, at the time of the exit of water through the bore in the blank flange, a leakage of the sealing system was detected at approximately 10 bar. In other words, the sealing system is tight up to a pressure of approximately 10 bar.

(42) In corresponding tests with the admixture piece 800 of FIG. 3, leakages even started occurring only at approximately 30 bar. Thus, this sealing system is tight even up to a pressure of approximately 30 bar.

(43) The admixture pieces 100 (FIGS. 1-2) and 800 (FIG. 5) made of polyurethane having a Shore A hardness of 75 and 90 and the housing element 200 (FIG. 3) made of POM-C were also tested in conventional arrangements for the application of spray concrete under various conditions. As has been shown, the devices according to the invention are at least as well suited for applying spray concrete as conventional systems, but the ease of handling during cleaning and replacement of the admixture piece is significantly better.

(44) However, the above described embodiments should only be understood as illustrative examples that can be used as desired in the context of the invention.

(45) For example, it is possible to replace, in the case of the admixture piece 100 of FIGS. 1-2, one or both of the sealing lips 110, 120 with an O ring. In the case of the first sealing lip 110, the O ring can be arranged, for example, so it bears against the front side of the flange 105.

(46) Similarly, it is possible to attach, in addition to the two sealing lips 110, 120, additional sealing elements, in particular additional sealing lips. Here, if necessary, conventional radial seals can also be provided. Thus, it becomes possible to further improve the sealing effect and/or to implement separate metering for adding different additives at different positions in the axial direction of the admixture piece.

(47) It is also possible to provide, in addition to or instead of the openings 103, additional or differently designed openings, for example, slits, in the wall of the admixture piece.

(48) In the case of the housing element 200 of FIG. 3, it is also conceivable, for example, to replace the inner cone surface 210 and/or the outer cone surface 220 with flat ring surfaces, in particular in order to simplify the manufacture of the housing.

(49) In addition, the housing element 200 can comprise, instead of or additionally to the radial bores 213a, 213b, additional or differently designed addition openings.

(50) The mixing section 101 of the admixture piece 100 and/or the through-flow opening 201 of the housing element 200 can also have a conically converging cross section. This can be advantageous, for example, to implement a current transformer.

(51) Similarly, it is also possible to manufacture the admixture piece 100, the base body 225 and/or the union nut 300 partially or completely from another material than plastic, for example, from steel and/or aluminum.

(52) Instead of the admixture piece 100, it is also possible to use the tubular admixture piece 800 from FIG. 5 in the apparatus set, the arrangement of FIG. 4, or during the installation/removal procedure.

(53) In summary, it should be noted that a novel admixture piece and associated housing element are provided, which can be handled considerably more simply and which at the same time allow reliable sealing.