DK173322B1 - Homogenizer and homogenizer housing - Google Patents

Description

in DK 173322 B1

The present invention relates to the homogenization of a liquid such as milk, and more precisely to the preparation of small amounts of a liquid to be analyzed, especially milk and dairy products, for analysis in milk quality testing equipment to control the production of dairy products. The present homogenisaphor is not intended for general treatment of 5 milk (This is meant for homogenization of human milk). It is intended for the preparation of samples of milk and dairy products to be analyzed.

Prior art

Homogenization has traditionally been performed using Gaulirv homogenizers, for example as described in The milk fat globule "by H. Mulder and P. Walstra, Center for Agricultural Publishing and Documentation Wageningen, the Netherlands 1974. Other homogenization methods may be" partial homogenization "," clarification "," blend ", or" ultrasound ", also mentioned by H. Mulder and P. Walstra. As is well known, conventional conventional homogenization is performed on a large scale on colostrum to provide a delicate milk product, as is preferred by many.

European patent application EP 0 034 675 discloses a method and apparatus for homogenizing a liquid. The homogenator is designed so that the fluid at high pressure from the valve 26 is passed through a narrow passage in the form of a circular slot with a razor-sharp 20 edge. The valve ensures that a back pressure is maintained on the exit side of the restricted passage (see column 2 line 63 - column 3, line 49). From WO 94/21110 A2 it is known to use hard stones, monocrystalline oxides in homogenizers.

Brief Description of the Invention

The object of the present invention is to provide an inexpensive, reliable homogenizer for small amounts of a composite, inhomogeneous liquid such as milk and milk products. This is achieved by providing a homogenizer comprising at least one restricted passage and with means for maintaining a pressure drop across the restricted passage, and the restricted passage comprising at least one narrow substantially tubular passage such as a nozzle and the homogenizer comprising means. for maintaining a back pressure in a chamber on the exit side of the restricted passage, which is characterized in that the restricted passage comprises a second nozzle arranged in series with and close to the first nozzle, since the two nozzles are usually a little offset ( so that the resulting flow area is limited to a value smaller than the opening area of a single nozzle and at least one of the nozzles is spring loaded and slidable (so that it can slide).

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With this arrangement, the cross-sectional area of the restricted passage can be varied. The event solves a problem that tends to occur frequently when treating milk. The diameter of the restricted passage, viz. the nozzle must be as small as possible to improve the homogenization effect. However, very small nozzles tend to become clogged. The proposed arrangement with a sliding nozzle solves the clogging problem. In case of clogging of the passage, the two nozzles can be aligned, whereby the clogging - the plug 'will pass and enable the homogenator to function again.

The restricted, generally tubular passage preferably has a circular, oval or elliptical cross section, or is composed of a number of circular sections - (in other words, it is substantially enclosed by an almost simply closed curve.) The main tubular passage may also be a thin slit. It is essential for the homogenization function to maintain a backpressure in the chamber on the exit side of the restricted passage.

The back pressure preferably exceeds at least 500,000 Pa, preferably at least 1000000 or 1500000 Pa and most preferably at least 2000000-2500000 Pa, such as 3000000 Pa. The pressure drop across the restricted passage can be from 3000000 to 40000000 Pa, preferably from 70000 to 35000000 15 Pa, and more preferably from 150000 to 25000000 Pa and preferably from 190000 to 23000000 Pa.

The optimum diameter of the opening in the inlet nozzle depends on the fluid to be homogenized. When milk is to be homogenized, the diameter may be from approx. 0.1 to 0.4 mm and preferably from ca. 0.15 to approx. 0.35 and preferably from ca. 0.18 to 0.3 mm. In the case of viscous 20 liquids, as is the case for many dairy products, such as yogurt, the diameter must not be too small to avoid clogging.

Preferably, the inlet nozzle is a generally circular portion having a diameter of approx. 1-4 mm for ex.

2 mm and a height up approx. 0.2-1 mm, e.g., 0.6 mm, provided with a through-hole having a diameter of 0.1 - 0.4 mm, e.g., 0.15 mm. The part should be made of a hard, durable and durable material, e.g. stones, such as bricks, made of e.g. sapphire, ruby, diamond, etc. Preferably the stone is mounted in a holder which also forms at least part of the backpressure chamber.

The new homogenizer is particularly advantageous in that the limited passage can be made of a hard-wearing and durable material such as a sapphire or ruby stone. In addition, during normal operation there are no moving parts and no wear due to movements. Thus, the new homogenizer will have a long life. In the one-stone embodiment, there are no moving parts at all in the homogenizer itself. This embodiment can be made very simple.

35 Brief Description of the Drawings

FIG. 1 schematically shows an enlarged section through a homogenizer according to the invention.

FIG. 2 shows an enlarged section through a preferred embodiment of a homogenizer according to the invention.

FIG. 3 shows a further enlarged section of the stones and stone holdings in the embodiment of FIG. FIG. 4 shows the homogenizer housing in the embodiment of Figure 2 enlarged.

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FIG. 5 shows the same housing from above (ie in a vertical projection of the same)

FIG. 6 shows a first stone holder In the embodiment of figure 2, enlarged.

Fig. 7 shows the stone holder in fig. 6 from the bottom.

FIG. 8 shows another stone holder in the embodiment of Figure 2, enlarged.

FIG. 9 shows the stone holder of FIG. 8, seen from the end and enlarged.

FIG. 10 shows an output port in the embodiment of FIG. 2 enlarged.

FIG. Figure 11 is an end view of the output port of Figure 10.

FIG. 12 shows a detail of Figure 1 further amplified.

DETAILED DESCRIPTION OF THE INVENTION In the following, a detailed description of examples of preferred embodiments of the present invention is given. A first embodiment, a very simple milk homogenizer 10 is shown schematically and enlarged in Figure 1. The homogenator comprises an inlet 12, a generally tubular, restricted passage 14 in a first wall 16 in a chamber 18 and an outlet opening 22 in a second wall of chamber 18. Passage 14 is narrow, like a nozzle. The output 22 may be located in a side wall or a bottom wall. The inlet 12 is connected to a milk supply through a high pressure pump which provides a pressure of 20000000 - 40000000 Pa at the inlet, thereby forcing a thin jet of milk through the nozzle 14. A back pressure valve (which is not shown as it may be of a known type) is disposed below (in the flow direction) chamber 18 to ensure a definite back pressure of preferably 0-3000000 Pa inside of chamber 18.

Function.

Figures 1 and 12 show the theory of the function of the new homogenizer. Currently, the following conditions / conditions are preferred, i.e. they have been found to be suitable for performing homogenization 25 effectively: A pressure of approx. 20000000-30000000 Pa, eg 25000000 Pa and a flow rate of approx.

3.6 m / s on the inlet, a back pressure of approx. 3000000 Pa on the outlet, a hole diameter of approx. 0.15 · 0.20 mm in a stone such as a brick. Preferably, the temperature of the milk and the chamber is about 40-50 ° C.

Under the above conditions, the following flow conditions are assumed to occur: Area A: 30 turbulent flow; area B: laminar flow, flow rate typically 200 m / s; area C: cavitation accompanied by an audible sound, size range of area C and sound frequency depends on the back pressure; Area D: turbulent flow, deacceleration zone; area E: slow vertebrae that move slowly around outside area D.

The homogenization is believed to occur when a thin jet of rapidly moving milk from areas A,

„B, C (in rapid motion due to the pressure drop across the restricted passage) in area D

hits the slow, almost stationary milk from the rear (area E) of the back pressure chamber. Whatever the reason may be, experience (supported by thorough measurements made on the starting product) has shown that it is a well homogenized milk leaving the chamber through exit 22. As seen from Figure 1, a homogenizer according to the invention can be be very simple.

The nozzle in the entrance opening passage 14 is very exposed to wear. In a preferred embodiment, S is made of a stone 24. The currently preferred stones are sapphires and rubies. The stone can be approx. 1 - 4 mm, for example 2mm in diameter and from approx. 0.2 to 1 mm high or thick eg 0.35 mm thick. In the preferred embodiment, the stone has a through-hole (14) having an internal diameter of 0.1 - 0.4 mm, preferably approx. 0.15 mm. The stone 24 is preferably mounted in a holder 20, such as a socket or frame, which is easy to replace when worn. Preferably, the rock holder 20 includes the back pressure chamber 18.

Figure 2 shows a currently preferred embodiment of the homogenizer. A housing 30 (shown in Figures 4 and 5) has a transverse passageway for the liquid inlet 32 and the liquid outlet 34 and a stepped borehole 36 in the center accommodates a first stone holder 40 with a first stone 42. The first stone holder 15 is shown in detail in Figure 6 and The first stone holder 40 comprises a cylindrical head 41 and a flat center stem 43. The first stone 42 is mounted in a through hole 44 in the stem 43. The stepped borehole 36 has three steps forming a first recess for sealing means 92 and a other recess that head 41 may encounter.

A stepped adjusting plug 80 is arranged in a stepped borehole 38 in the center of the bottom of the housing 30. The adjusting plug 80 includes a flange portion 85, an adjusting screw 82 and a pin 84. The pin 84 supports the lower end of the first stone holder 40. The flange portion 85 is used. for fixed mounting of plug 80 to housing 30, for example, flange portion 85 includes means for attaching plug 80 to housing 30, e.g., two or four boreholes in flange portion 85 as well as two or four threaded holes in housing 25 and two or four threaded screws. Due to the high pressure on the entrance, careful mounting of stone holder and plugs is essential. Such mounts are well known and will not be explained in detail.

A cylindrical sleeve 47 with a flange portion 45 is mounted on top of housing 30. For example. bolted into threaded holes 30 35 (Figure 5). The sleeve 47 controls a portion 46 which is followed by a spring 48 and a threaded plug 49. By appropriate adjustment of the plug 49, the spring 48 will ensure a predetermined pressure on the portion 46 and thus on the first rock holder 40. The predetermined spring pressure should be, for example, 1000000 -5000000 Pa greater than the homogenization pressure (The high pressure on the Inlet 63). However, this arrangement can be realized in many ways.

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An essential feature of the invention is that the first stone 42 is arranged to slide or move (slidably) along the side surface of a second stone 52 in a second stone holder 50, shown in detail in Figures 8 and 9. The second stone 52 is substantially similar to and disposed adjacent to the first stone 42. The arrangement is shown in detail in Figure 3. Each of the stone holders forms a holder 40 or socket for the stone, the exterior of the stone smoothly passing into the surface of the holder. The second DK 173322 B1 5 bracket 50 (Figures 8 and 9) comprises a cylinder 54 which is accommodated in an outlet opening 34 of the housing 30. The stone 52 is mounted in an opening at the bottom of the cylinder 54, as shown in Figure 3. The outer end of the second stone holder 50 comprises a flange 55. The flange 55 is used to attach the stone holder to the housing 30, e.g. bolted through holes 51, 53 (Figures 8 and 9). The second stone holder 50 5 Contains the backpressure chamber 18. The backpressure chamber is located inside the cylinder 54 between the end wall 56 (Figure 3.8) and an outlet plug 70.

The two holes in the stones 42, 52 are substantially the same size, e.g. with a diameter of 0.4 mm but are usually offset with each other so that the resulting passage is narrower (e.g. 0.15 10 mm) than the passage through a single hole.

The milk inlet is arranged through the opening I or borehole 32 which is perpendicular to the borehole 36 to the holder 40 for the first stone 42. Preferably, the inlet opening 32 (the borehole) continues through the housing 30 and passes directly into the outlet arrangement. The inlet comprises an inlet plug or connector, such as a pipe piece 60, with a through-bore 63, with threads adapted to be connected to milk supply means such as a hose. The inlet plug 60 comprises a cylindrical portion 61 which is accommodated in the inlet opening 32 as well as a flange portion 62 adapted to be fixedly mounted on the housing 30. A spring 64 is arranged between the end of the cylinder portion 61 and the first stone holder 40. The spring 64 secures the stone holder 40 holds a 20 position which ensures close interaction between the two stones 42 and 52, ie. that the two stones are constantly close together.

An outlet port is constituted by a further plug or pipe 70 with a cylinder portion 65 within a cylindrical holder 50.1, a currently preferred embodiment is the outlet of the backpressure chamber 25 18 arranged through grooves or grooves 67,69 at the end of the cylinder portion 65 of the plug 70 (shown in FIG. details in Figures 10 and 11). The grooves 67,69 are again in contact with radial channels 68 which open into a longitudinal center channel 66. A flange portion 71 is arranged to all be attached to the flange portion 55 of the second stone holder 50. A groove 74 receives a sealing ring or gasket. However, the outlet can be arranged in many ways, e.g. like the inlet plug 60. It is clear that the parts 30, 47, 50, 30, 60, 70, 80 must be assembled tightly. This can be done in many ways. In order to simplify the drawing, the actual fastening means (which are of a known kind) are not shown in full detail, only occasionally mentioned as threaded bolts, holes 51, 53, threaded holes and sealing means such as sealing rings 91, 92, 93, 94 (only shown in FIG. 2) in recesses or grooves such as 74 (shown in Figure 10.) 35 As previously described with reference to Figure 1, the homogenization takes place on the back of the rock pair 42, 52 inside the baking chamber 18 in the rock holder 50. The function is the same as described with reference to Figure 1. In the preferred arrangement, the hole diameter is 0.4 mm and during normal operation the mean width of the passage through the staggered stones is about 0.1 - 0.15 mm. In this way, the throughput area can be quite small, substantially smaller than the throughput area 40 for a single hole.

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The purpose of this arrangement is explained below: To achieve good homogenization, it is essential that the hole is small, thereby creating a high flow rate through the hole. However, a very small hole causes one problem: clogging. Crude milk is a composition, S which may contain impurities and agglomerations which may clog the small hole. In the prior art homogenizers using valve seats, this is no problem as the valve seats are usually spring loaded and will therefore open if they are clogged by something.

The embodiment of Figure 2 having the spring loaded rock holder 40 solves this problem with the 10 new homogenizer.

Function:

The homogenization takes place in the same way as explained earlier with reference to Figure 1. The embodiment of Figure 2 is advantageous in that clogging can be avoided. If the passage through the 1S stone holes becomes clogged, the pressure on the high pressure side of the stones (left side in Figures 1 and 2) will increase.

The increased pressure will act on the holder 40 and lift it a few tenths of a mm just enough to increase the passage through the opening to the full hole diameter of, for example, 0.4 mm.

Thereby, the clogging of the passage will be released / released, the increased pressure will be released and the holder 40 20 will again move downwards and again limit the passage. With these agents, the homogenizer becomes "self-cleaning". In the event that the holder does not itself move upwardly solely by the increased pressure, an upward movement can be ensured by turning the adjustment screw 82 and thereby manually lifting the stem 43.

As can be seen from the foregoing description, a new simple homogenizer is provided. The homogenizer is particularly suitable for preparing milk samples of dairy products to be analyzed, but can also be used to prepare samples of other inhomogeneous liquids.

Claims (9)

A homogenizer (10), comprising at least one restricted passageway (14) with a first nozzle, and with means for maintaining a pressure drop over the restricted passage (14), and the homogenizer 5 (10) comprising means for maintaining a back pressure in a chamber (18) on the exit side of the restricted passage (14), characterized in that the restricted passage (14) comprises a second nozzle arranged in series with and adjacent to the first nozzle, and that the two nozzles are usually slightly displaced such that the resulting flow area is limited to a value smaller than the opening area of a single nozzle and that at least one of the nozzles is spring-loaded and 10 so that it can slide (slidably). Homogenizer (10) according to claim 1, characterized in that the restricted passage (14) has a cross-section composed of a number of circular sections. Homogenizer (10) according to claim 2, characterized in that the cross-section is composed of two substantially identical circular sections. Homogenizer (10) according to claim 1, characterized in that the diameter of the restricted passage (14) is approx. 0.1 to 0.4 mm and preferably from ca. 0.15 to 0.35 mm and most preferably about 0.18 - 0.3 mm. 20 The homogenizer (10) of claim 4, wherein the restricted passageway (14) is provided with a generally circular rock (24), such as a sapphire beer a ruby, characterized by. the stone (24) has a diameter of approx. 1 - 3 mm, preferably approx. 2 mm and a height of approx. 0.3 mm is provided with a through hole having a diameter of 0.1 tH 0.5 mm, preferably from 0.15 - 0.4 mm. 25 Homogenizer (10) according to one of claims 1-5, characterized in that at least one stone (52) is mounted in a holder (20,50) which also forms at least part of the backpressure chamber (18). Homogenizer (10) according to one of claims 1 to 8, for milk or milk products, characterized in that the back pressure in the back pressure chamber (18) is from 0 to 5000000 Pa, preferably exceeding at least 500000 Pa, preferably at least 1000000 or 1500000 Pa, and preferably at least 2000000 - 2500000 Pa, such as 3000000 Pa. Homogenizer (10) according to any one of claims 1-6, for milk or milk products, characterized in that the pressure drop over the restricted passage is from 3000000 to 40000000 Pa, preferably from 7000000 to 35000000 Pa. more preferably from 15000000-25000000 Pa and preferably approx. 19000000-23000000 Pa. Homogenizer housing (30) for a homogenizer according to one of claims 1-8, characterized in that it comprises two mutually perpendicular channels, i. a vertical channel (36, 38) for displacing the 40 sliding (sliding) rock holder (40), and a horizontal channel (32. 34) for the flow of fluid from Inlet to Outlet.