Device and method for aseptic pressure relief

Abstract

A pressure-relief device includes a housing, a through-line, a feed-line connection, and a discharge-line connection. The housing comprises a housing wall that defines a chamber in an interior of the housing. The through-line, which extends, at least in sections, through the chamber and is configured for connection to the media line via the feed-line connection and the discharge-line connection, includes a through-wall that is formed, at least in part, from an elastically deformable material. A controller causes an inner pressure within the chamber to transition between a production pressure and a relief pressure that is less than the production pressure.

Claims

1. An apparatus comprising a pressure-relief device for relieving pressure in a media line and a pressure-control unit for controlling said pressure-relief device, said pressure-relief device comprising a housing, a through-line, a feed-line connection, and a discharge-line connection, wherein said housing comprises a housing wall that defines a chamber in an interior of said housing, wherein said through-line, which extends, at least in sections, through said chamber and is configured for connection to said media line via said feed-line connection and said discharge-line connection, includes a through-wall that is formed, at least in part, from an elastically deformable material, and wherein said pressure-control unit causes an inner pressure within said chamber to transition between a production pressure and a relief pressure that is less than said production pressure, wherein said pressure-control unit is configured to cause said inner pressure to transition from an actual value to a reference value.

2. The apparatus of claim 1, wherein said through-wall connects to said housing via a pressure-tight connection.

3. The apparatus of claim 1, wherein said feed-line connection and said discharge-line connection are configured such that, when said pressure-relief device is connected to said media line, said feed-line connection and said discharge-line connection connect to said media line in a pressure-tight manner and wherein medium flows into said through-line from a first end, which faces said feed-line connection, to a second end, which faces said discharge-line connection.

4. The apparatus of claim 1, wherein said through-wall is formed completely from said elastically deformable material.

5. The apparatus of claim 1, wherein said elastically deformable material of said through-wall is fluid-tight.

6. The apparatus of claim 1, wherein said elastically deformable material is resistant to chemical reaction with substances that are passed through said media line.

7. The apparatus of claim 1, wherein said elastically deformable material is resistant to temperatures of substances that are passed through said media line.

8. The apparatus of claim 1, wherein said pressure-control unit comprises a computer.

9. The apparatus of claim 1, wherein said pressure-control unit comprises a sensor that detects inner pressure of said chamber.

10. The apparatus of claim 1, wherein said pressure-control unit is configured to impose compressed air on said chamber.

11. A method comprising relieving pressure in a media line, wherein relieving pressure comprises using a pressure-relief device that has been integrated into said media line, said pressure-relief device comprising a housing having a housing wall that defines a chamber within an interior of said housing and a through-line that connects to said media line via a feed-line connection and a discharge-line connection, said through-line having a through-wall that extends, at least in sections, through said chamber and that comprises an elastically deformable material, wherein said method comprises causing an inner pressure within said chamber to transition to a relief pressure that is less than a production pressure, thereby causing said through-line to expand in volume, wherein causing said inner pressure to transition comprises causing said inner pressure to transition from an actual value to a reference value.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) These and other features of the invention will be apparent from the following detailed description and the accompanying figures in which:

(2) FIG. 1 shows a pressure-relief device in a first operational state, in which it connects to a media line at production pressure;

(3) FIG. 2 shows the pressure-relief device of FIG. 1 in a second operational state under relief pressure;

(4) FIG. 3 shows a cut-away view of a housing wall of the pressure-relief device of FIG. 1 in the first operational state under production pressure;

(5) FIG. 4 shows a cut-away view of a housing wall of the pressure-relief device of FIG. 3 in the second operational state under relief pressure;

(6) FIG. 5a is a section in the direction of a main axis of a section of a through-wall in the first operating state under production pressure; and

(7) FIG. 5b shows the section of FIG. 5a during adjustment of the relief pressure.

(8) Identical reference numbers are used for those components that are the same or that have the same effect. To avoid clutter, only those references numbers that are useful for understanding the discussion of a particular figure are shown in that figure.

DETAILED DESCRIPTION

(9) FIG. 1 shows a pressure-relief device 1 for relieving pressure in a media line 11 in a container-treatment system, and in particular, in a filling machine.

(10) The configuration shown in FIG. 1 represents the pressure-relief device 1 in a first state. This first state corresponds to normal operation. During normal operation, the media line 11 typically carries product under pressure. This pressure, which is referred to herein as “production pressure,” conveys product, such as a beverage, to from a storage container, such as a beverage cellar, to a filling head 15 or to a filling valve 14. The pressure prevailing in the media line 11 is thus the production pressure.

(11) The pressure-relief device 1 extends along a main axis HA. A feed-line connection 2 and a discharge-line connection 3 connect the pressure-relief device 1 to the media line 11. As a result, the pressure-relief device 1 is an intermediate piece in a fluid path that includes the media line 11.

(12) The media flows in a flow direction R that defines an upstream and downstream direction. As shown in FIG. 1, the pressure-relief device 1, which extends along the flow direction R, is downstream of a shutoff valve 13 and upstream of a filling valve 14. This shutoff valve 13 interrupts a connection to the beverage cellar.

(13) The pressure-relief device comprises a housing 4 that includes a housing wall 7. The housing wall 7 defines a pressure chamber 6 within the housing's interior. A through-line 5, through which the medium flows, connects to the media line 11. A through-wall 8 that extends along the housing's interior surrounds the through-line 5.

(14) The through-line 5, which is made of an elastically deformable material, extends through the pressure chamber 6 along the direction of the main axis HA between the feed connection 2 and the discharge-line connection 3. The feed connection 2 and the discharge-line connection together connect the through-line 5 to the media line 11. As a result, the medium flows in the flow direction R between first and second ends 5.1, 5.2 of the through-line 5.

(15) During the first state, a controller 10 maintains a predefined first pressure P1 within the pressure chamber 6. This first pressure P1 matches the pressure prevailing in the line 11 and, as a result, the pressure in the through-line 5. At the first pressure P1, the through wall 8 does not extend significantly. Thus, at the first pressure P1, the through wall 8 defines an essentially cylindrical volume V1, as shown in FIGS. 1 and 3.

(16) During the second state, the controller 10 maintains a predefined second pressure P2 in a second state, shown in FIG. 3. This second pressure P2 is lower than the first pressure P1. Since the second pressure P2 is lower, it is useful to refer to it as a “relief pressure.”

(17) Upon occurrence of a fault, closing either the automatic shutoff valve 13 or the manual shutoff valve 12 interrupts a connection between the media line 11 and the media source. At the same time, or soon thereafter, the controller 10 establishes the second pressure P2 in the pressure chamber 6.

(18) Since the second pressure P2 is lower than the first pressure P1, the through-wall 8 expands, as shown in FIG. 2. In doing so the through-wall 8 defines a second volume V2 that exceeds the first volume V1. This second volume V2 defines a “relief volume.”.

(19) The extent of the change in the through-wall's volume, and hence the change in the through-line's volume, is a function of the difference between the production pressure and the relief pressure. The through-wall's expansion depends on a ratio of a first force FA, which acts on a first side 8.1 of the wall 8 and a second force FI, which acts on a second side 8.2 of the wall 8, as shown in FIGS. 5a and 5b. The first side 8.1 faces the pressure chamber 6. Accordingly, controller 10 can adjust the first force FA by adjusting the pressure in the pressure chamber 6.

(20) Given the values of the compressibility of the medium flowing through the media line 11 and the through-line 5, a small expansion of the through-line 5 causes a substantial fall in pressure. Thus, any risk associated with excessive pressure in the medium flowing through the media line 11 and the through-line 5 can be mitigated by suitable adjustment of the second pressure P2.

(21) The compressibility of a volume V of liquid is given by a relationship between a differential change dV in its volume and the accompanying differential change dP in pressure, namely dV/(V*dP). For water, this is on the order of 0.5 per gigapascal. Thus, even a small change in the through-line's volume as a result of elastic deformation of the through-wall 8 is sufficient to reduce the pressure of a water-based medium.

(22) FIGS. 3 and 4 show the pressure-relief device 1 with the housing wall 7 having been partially sectioned along the axis HA.

(23) In FIG. 3, the pressure-relief device 1 is operating in the first state, in which the pressure is the production pressure. In this state, the diameter of the through-line 5 conforms to that of the media line 11. This results in unhindered flow through the through-line 5.

(24) In FIG. 4, the pressure-relief device 1 is operating in the second state, in which the pressure is the relief pressure.

(25) The through-wall 8 of the through-line 5 is produced entirely from an elastically deformable material. In a preferred embodiment, the elastically deformable material is resistant to temperature as well as to cleaning and disinfection agents that are conventionally used for container-treatment systems. In one embodiment, the resistance of the through-wall 8 to various agents is summarized in the following table:

(26) By way of example, specific data is listed in the following table with regard to the resistance of the through-wall 8 in relation to different cleaning and disinfection agents:

(27) TABLE-US-00001 Daily contact Cleaning agent Concentration Temp. time Alkaline cleaning up to 3% 85° C. 45 minutes using NaOH Combined cleaning and up to 3% 80° C. 45 minutes disinfection using NaOH and Na hydrochloride (pH = 12) Acidic cleaning using up to 1.5% 30° C. 30 minutes H.sub.3PO.sub.4 (phosphoric and nitric acid) Disinfection using Na up to 300 ppm 30° C. 45 minutes hydrochloride (pH = 9) active chlorine Disinfection with up to 0.3% 30° C. 16 hours acetic acid (PES) with chloride content of the operational water of up to 300 ppm Disinfection using up to 100 ppm 30° C. 16 hours iodophor with chloride active iodine content of the operational water of up to 300 ppm Hot water — 95° C. 45 minutes Steam — 130° C. Sustained contact Ozone 600 mf/m.sup.3 air 0-30° C. —

(28) In the first state, the first pressure P1, which prevails in the pressure chamber 6, is set equal to the production pressure. As a result, the two forces balance and the through-wall 8 of the through-line 5 does not expand. Accordingly, the through-line 5 remains essentially cylindrical with a first first volume V1.

(29) FIGS. 5a and 5b show the forces acting on a section of through wall 8 identified in FIG. 4 by the elliptical broken line A in FIG. 3.

(30) FIG. 5a shows the first state. In this first state, the forces FI and FA are balanced. The ratio of the forces, FI/FA, is therefore approximately unity. As a result, the through-wall 8 experiences no net force. Therefore, it does not flex outward.

(31) FIG. 5b shows the second state, in which the second pressure has been reduced to the second pressure P2. In this second state, the forces are unbalanced, with FI being greater than FA. As a result, the through-wall expands.

(32) As shown in FIG. 4, in the second state, the lower second pressure P2 allows the first pressure P1 to cause the through-line 5 to camber outward towards the pressure chamber 6 so that its belly protrudes into the pressure chamber 6. This results in an increased volume V2. In a typical embodiment, the through-line 5 adopts the shape of an ellipsoid having a major axis along the main axis HA.

(33) A difference between the first and second volumes results in an expansion volume. The expansion volume permits the medium contained in the through-line 5 to be distributed over a larger volume. This reduces its pressure. As a result, it is possible to efficiently reduce the pressure in the media line 11.

(34) The controller 10 adjusts the pressure chamber's inner pressure. In a preferred embodiment, the controller 10 includes a computer 9.

(35) The controller 10 is also able to significantly reduce the pressure within the pressure chamber 6, thus allowing the elastically deformable through-wall 8 to expand to an even greater extent. In an extreme case, the through-wall 8 expands enough to be partially in contact with an inner side of the housing's wall 7. This permits an even larger expansion volume for greater pressure relief.

(36) The relief pressure is preferably greater than zero. In a preferred embodiment, the relief pressure is selected such that the pressure within the medium remains above some desired minimum value and that gas dissolved in the medium remains dissolved. This is particularly important for a carbonated beverage, in which the dissolved gas is typically carbon dioxide.

(37) Upon completion of maintenance or repair, the container-treatment machine is brought back into service. Doing so includes having the control unit 10 raise the pressure in the pressure chamber 6 back to the first pressure P1. As a result, the medium is brought back to production pressure.

(38) The invention has been described heretofore on the basis of exemplary embodiments. It is understood that numerous modifications and derivations are possible, without thereby departing from the inventive concept underlying the invention.