A guiding device for use in a homogenizing valve and a homogenizing valve comprising said guiding device

Abstract

A guiding device (1) for use in a homogenizing valve (200), the guiding device (1) comprising: • - a shaft (2); • - a hollow case (3) having a cylindrical symmetry and passing through the hollow case (3); • - a guide (4) fitted between an inner wall (3a) of the hollow case (3) and the shaft (2), the guide (4) being made of an elastic material, wherein the guide (4) is a double-cone gasket having a rotational symmetry with a tapering development from a central portion (14) towards a first conical end (15) of the guide (4) and a tapering development from the central portion (14) towards a second conical end (16) of the guide (4) which is opposite to the first conical end (16).

Description

[0001] DESCRIPTION

[0002] A GUIDING DEVICE FOR USE IN A HOMOGENIZING VALVE AND A HOMOGENIZING VALVE COMPRISING SAID GUIDING DEVICE Technical field

[0003] The present invention relates to a guiding device for use in a homogenizing valve and a homogenizing valve comprising said guiding device.

[0004] The invention proposed here is used in the food industry, in particular in the dairy sector, or in the chemical, pharmaceutical or cosmetic industry. The invention can also be used in manufacturing areas where homogenization is a step of the production process.

[0005] Consider, for example, the production of carbon-based nanostructured materials, such as graphene and carbon nanotubes or cellular breakdown of yeasts, algae, or microorganisms for the production of intracellular material.

[0006] Background art

[0007] As it is well-known, apparatus for homogenising fluids crush the particles, reducing their dimensions to a minimum and make the dimensions of the particles uniform, thus reducing variation of distribution of the dimensions of the particles.

[0008] Said homogenising apparatus, also in the different embodiments so far known, comprise a high-pressure pump and a homogenising valve. The homogenising valve comprises a first chamber receiving the fluid at high pressure from the pump delivery and a second chamber capable of supplying outgoing homogenised fluid at low pressure. The homogenising action is obtained by forcing the fluid to pass through an interspace or gap with reduced dimensions afforded between the first and the second chamber. The gap is defined by a passage head integrally joined to the valve body and by an impact head axially mobile with respect to the passage head.

[0009] The fluid coming from the inlet presses on a surface of the impact head exerting on it a pressure which tends to widen the gap.

[0010] A pusher capable of contrasting the pressure of the fluid in an axial direction is applied to the impact head. The dimension of the gap is controlled by acting directly on the pusher as a function of the valve flow rate and pressure operating values.

[0011] As already indicated above, the fluid loses pressure by passing through the gap and is simultaneously accelerated, thus allowing fragmentation of the particles in suspension.

[0012] Disclosure of the invention

[0013] In order to optimise the energy used in the homogenisation process, over recent years, the Applicant has developed homogenising valves in which the first and the second chamber have an annular shape. Said solutions are described in European patent EP810025 and in Italian patent no. 1385953 in the name of the Applicant.

[0014] The annular configuration of the two chambers allows the fluid at high pressure to press on an annular surface of the impact head, thus allowing operation with a gap of reduced dimensions with the same energy applied. One limit of the solution just described lies in the form and position of the pusher acting on the impact head. In some solutions, the pusher consists in a shaft integrally fixed to the impact head and located in the upper part of the homogenizing valve.

[0015] Under the pushing action of the shaft, the impact head is moved downwards, that means towards the gap.

[0016] Actuating the impact head far from the working area, which is the gap, introduces tolerances that may result in an undesired mechanical misalignment. The higher is the misalignment, the worse is the performance of the homogenizing valve.

[0017] Cylindrical sleeves made of anti-friction materials are usually employed for guiding the shaft, which nevertheless are affected by misalignment issues, which may result highly critical in case of high pressures and high flowrates. Misalignments can also give rise to vibrations and undesired noise.

[0018] In this context, the object of the present invention is to provide a guiding device for use in a homogenizing valve, which overcomes the problems of the prior art cited above.

[0019] In particular, the object of the present invention is to propose a guiding device for use in a homogenizing valve, which is more accurate and reliable, avoiding or at least decreasing the risks of mechanical misalignments.

[0020] The stated technical task and specified aims are substantially achieved by a guiding device for use in a homogenizing valve, the guiding device comprising:

[0021] - a shaft;

[0022] - a hollow case having a cylindrical symmetry, the shaft passing through the hollow case;

[0023] - a guide fitted between an inner wall of the hollow case and the shaft, the guide being made of an elastic material.

[0024] Advantageously, the guide is a double-cone gasket having a rotational symmetry with a tapering development from a central portion towards a first conical end of the guide and a tapering development from the central portion towards a second conical end of the guide which is opposite to the first conical end.

[0025] According to an aspect of the invention, the double-cone gasket has an annular external notch facing the inner wall of the hollow case.

[0026] Preferably, the annular external notch is obtained in the central portion of the double-cone gasket.

[0027] In one embodiment, the double-cone gasket has an inward inner wall with respect to an axis of symmetry of the hollow case.

[0028] In one example, the guide is made of PTFE.

[0029] Alternatively, the guide is made of PEEK.

[0030] The hollow case is preferably made of anti-friction steel

[0031] According to one aspect of the invention, the hollow case comprises a tubular body and a threaded plug applied at a first end of the tubular body. The first end of the tubular body is internally threaded so as to receive the threaded plug.

[0032] The tubular body has a second end that is inwardly bent so as to define a disc-shaped base through which the shaft is received.

[0033] The double-cone gasket is arranged in the hollow case and extend from the threaded plug to the second end of the tubular body.

[0034] In particular, the first conical end of the double-cone gasket faces the threaded plug, and the second conical end of the double-cone gasket faces the second end of the tubular body.

[0035] The stated technical task and specified aims are substantially achieved by a homogenizing valve comprising:

[0036] - a guiding device according to the invention;

[0037] - a valve body defining a through-hole having axial development with respect to the valve body;

[0038] - a passage head integrally connected to the valve body;

[0039] - an impact head integrally connected to said shaft;

[0040] - a gap defined by the passage head and the impact head.

[0041] Brief description of drawings

[0042] Further characteristics and advantages of the present invention will more fully emerge from the non-limiting description of a preferred but not exclusive embodiment of a guiding device for use in a homogenizing valve, as illustrated in the accompanying drawings in which:

[0043] - figures 1 illustrates a homogenizing valve with a guiding device, according to the invention, in a longitudinal cross-sectional view;

[0044] - figures 2 and 3 illustrate a double-cone gasket of the guiding device of figure 1 , respectively in a longitudinal cross-sectional view and in a perspective view.

[0045] Detailed description of preferred embodiments of the invention

[0046] With reference to the figures, number 1 indicates a guiding device for use in a homogenizing valve 100. The guiding device 1 comprises a shaft 2 having an elongated development. In particular, the shaft 2 has a cylindrical symmetry with respect to a longitudinal axis AA.

[0047] The guiding device 1 further comprises a hollow case 3 having a cylindrical symmetry so as to receive the shaft 2.

[0048] In particular, the hollow case 3 is coaxial to the shaft 2. Therefore, the axis of symmetry of the hollow case 3 coincides with the longitudinal axis A-A of the shaft 2.

[0049] The shaft 2 is arranged within the hollow case 3 so as to pass through it. At least a portion 2a of the shaft 2 is inside the hollow case 3. This portion, indicated with 2a, is referred to as “inner portion” of the shaft 2.

[0050] The rest of the shaft 2 is outside the hollow case 3.

[0051] In particular, a first end portion 2b of the shaft 2 and a second end portion 2c of the shaft 2 protrude outside the hollow case 3.

[0052] A guide 4 is fitted between an inner wall 3a of the hollow case 3 and the shaft 2.

[0053] In particular, the guide 4 is interposed between the inner wall 3a of the hollow case 3 and the inner portion 2a of the shaft 2.

[0054] Advantageously, the guide 4 is a double-cone gasket.

[0055] The double-cone gasket 4 has a rotational symmetry with a tapering development from a central portion 14 of the double-cone gasket 4 towards a first conical end 15 of the double-cone gasket 4 and a tapering development from the central portion 14 towards a second conical end 16 of the double-cone gasket 4 which is opposite to the first conical end 15.

[0056] In other words, the double-cone gasket 4 is gasket with both faces conical. Due to the double taper of the faces of the gasket 4, the outermost part is much smaller, and it is therefore easy for it to be deformed by applying just a minimum load.

[0057] According to a preferred embodiment, the double-cone gasket 4 has an annular external notch 17 facing the inner wall 3a of the hollow case 3.

[0058] In particular, the annular external notch 17 is obtained in the central portion 14 of the double-cone gasket 4.

[0059] The double-cone gasket 4 further has an annular internal notch 18, which is obtained oppositely to the annular external notch 17 with respect to the central portion 14 of the double-cone gasket 4.

[0060] More preferably, the double-cone gasket 4 has an inward inner wall 18, that is an inner wall 1 which is obtained inwardly the double-cone gasket 4. For example, the inward inner wall 18 is curved towards the inside of the central portion 14.

[0061] In particular, the central portion 14 of the double-cone gasket 4 has said inward inner wall 18.

[0062] The annular external notch 17 is obtained opposite the inward inner wall 18 in the central portion 14 of the double-cone gasket 4.

[0063] According to an embodiment of the invention, the hollow case 3 comprises a tubular body 5 and a threaded plug 6 applied at a first end 5a of the tubular body 5. The first end 5a of the tubular body 5 is internally threaded so as to receive the threaded plug 6.

[0064] As a matter of fact, the threaded plug 6 can be screwed more or less tight to the first end 5a of the tubular body 5.

[0065] In particular, the threaded plug 6 is hollow so as to receive the shaft 2.

[0066] The tubular body 5 has a second end 5b that is inwardly bent so as to define a disc-shaped base through which the shaft 2 is arranged.

[0067] Advantageously, the double-cone gasket 4 is arranged in the hollow case

[0068] 3 from the threaded plug 6 and the disc-shaped base 5b (that is the second end of the tubular body 5).

[0069] In particular, the first conical end 15 of the double-cone gasket 4 faces the threaded plug 6, and the second conical end 16 of the double-cone gasket

[0070] 4 faces the disc-shaped base 5b.

[0071] According to one aspect of the invention, the guide 4 is made of an elastic material.

[0072] Preferably, the guide 4 is made of PTFE.

[0073] In an alternative embodiment, the guide 4 is made of PEEK. The hollow case 3 is preferably made of anti-friction steel.

[0074] By screwing the threaded plug 6 to the first end 5a of the tubular body 5, the double-cone gasket 4 is compressed within the hollow case 3.

[0075] The level of compression may be adjusted by screwing less or more the threaded plug 6 to the first end 5a of the tubular body 5.

[0076] In particular, unscrewing the threaded plug 6 allows to release the doublecone gasket 4.

[0077] Number 200 identifies a homogenizing valve comprising a valve body 201 defining a through-hole having axial development with respect to the valve body 201 .

[0078] The homogenizing valve 200 comprises a guiding device 1 according to the proposed invention, as shown in figure 1 .

[0079] The guiding device 1 is housed in the through-hole defined by the valve body 201 .

[0080] In particular, the guiding device 1 is located in an upper part of the homogenizing valve 200.

[0081] The homogenizing valve 200 has a gap wherein a fluid to be homogenized is accelerated.

[0082] The gap is defined by a passage head 202 that is integrally connected to the valve body 201 and an impact head 203 that is integrally connected to the shaft 2.

[0083] The homogenizing valve 200 has an inlet 204 for a fluid at high pressure and an outlet 205 for homogenized fluid at low pressure.

[0084] The impact head 203 is actuated by the shaft 2.

[0085] Under the pushing action of the shaft 2, the impact head 203 is moved downwards, that means towards the gap that receives the fluid from the inlet 204 and delivers it to the outlet 205.

[0086] The characteristics of the guiding device for use in a homogenizing valve emerge clearly from the above description, as do the advantages.

[0087] In particular, the double-cone gasket allows reducing misalignments. The threaded plug can indeed be screwed more tightly so as to press the first conical end of the gasket. Therefore, the friction force exerted on the shaft can be adjusted by screwing the threaded plug.

[0088] This achieves the desired tightening torque of the guiding device, which can be changed depending on the needs. In addition, this allows to counteract vibrations and noises caused by resonance conditions. Indeed, thanks to the double-cone gasket made of elastic material the resonance point may be adjusted.

[0089] Finally, the lifetime of the shaft is increased with respect to the known solutions.

Claims

CLAIMS1. A guiding device (1 ) for use in a homogenizing valve (200), said guiding device (1 ) comprising:- a shaft (2);- a hollow case (3) having a cylindrical symmetry, said shaft (2) passing through the hollow case (3);- a guide (4) fitted between an inner wall (3a) of the hollow case (3) and the shaft (2), said guide (4) being made of an elastic material, characterized in that said guide (4) is a double-cone gasket having a rotational symmetry with a tapering development from a central portion (14) towards a first conical end (15) of the guide (4) and a tapering development from said central portion (14) towards a second conical end (16) of the guide (4) which is opposite to the first conical end (16).

2. The guiding device (1 ) according to claim 1 , wherein said double-cone gasket (4) has an annular external notch (17) facing the inner wall (3a) of the hollow case (3).

3. The guiding device (1 ) according to claim 2, wherein said annular external notch (17) is obtained in the central portion (14) of the doublecone gasket (4).

4. The guiding device (1 ) according to any one of the preceding claims, wherein said double-cone gasket (4) has an inward inner wall (18) with respect to an axis of symmetry (A-A) of the hollow case (3).

5. The guiding device (1 ) according to any one of the preceding claims, wherein said guide (4) is made of PTFE.

6. The guiding device (1 ) according to any one of the claims 1 to 4, wherein said guide (4) is made of PEEK.

7. The guiding device (1 ) according to any one of the preceding claims, wherein the hollow case (3) comprises a tubular body (5) and a threaded plug (6) applied at a first end (5a) of the tubular body (5), said first end (5a) of the tubular body (5) being internally threaded so as to receive the threaded plug (6).

8. The guiding device (1 ) according to claim 7, wherein the tubular body (5) has a second end (5b) that is inwardly bent so as to define a discshaped base through which the shaft (2) is received.

9. The guiding device (1 ) according to claim 8, wherein the double-cone gasket (4) is arranged in the hollow case (3) and extend from the threaded plug (6) to the second end (5b) of the tubular body (5).

10. The guiding device (1 ) according to claim 9, wherein the first conical end (15) of the double-cone gasket (4) faces the threaded plug (6), and the second conical end (16) of the double-cone gasket (4) faces the second end (5b) of the tubular body (5).

11. The guiding device (1 ) according to any one of the preceding claims, wherein said hollow case (3) is made of anti-friction steel.

12. A homogenizing valve (200) comprising:- a guiding device (1 ) according to any one of the preceding claims; - a valve body (201 ) defining a through-hole having axial development with respect to the valve body (201 );- a passage head (202) integrally connected to the valve body (201 );- an impact head (203) connected to said shaft (2);- a gap defined by the passage head (202) and the impact head (203).

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