JPS5825495B2 - Equipment for sterilizing and/or homogenizing fluid products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for sterilization and/or homogenization of fluid products.

More particularly, the invention relates to a device for sterilization and/or homogenization of fluid products by injection of water vapor, the device being formed by a straight tube and a tubular arm for introducing the fluid product. It consists of a T-shaped body and a steam injection nozzle located axially at the first end or inlet of the tube and opening into the mixing zone at the junction between the arm and the tube.

Various types of devices are already known for sterilizing fluid edible products by injection of steam.

Some are based on the principle of injecting water vapor into the product, while others are based on the principle of injecting the product into the water vapor or the water vapor and the product into a mixing chamber.

This last type of device has proven suitable for most products in question.

One known model of this type includes two nozzles, each having an initially converging and then diverging cross-section, and arranged one behind the other in a straight tube of a T-shaped body;
The outlet end of the first nozzle projects into the inlet end of the second nozzle at the junction between the tube and the tubular arm.

Steam is injected under pressure into the first nozzle, the product is introduced under pressure into the tubular arm, and the product is mixed in the second nozzle, which acts as a mixing chamber.

Operation of this device gives satisfactory results for most products, especially highly viscous products, such as low moisture flour mixes or processed cheese pastes.

However, this type of device must be oversized if it is to be sterilized and the fluid product collection is to be prevented from clot formation downstream of the mixing chamber.

The possibility of clot formation is hampered by the strong turbulence that prevails within the mixing chamber, but the degree of turbulence decreases beyond the mixing chamber.

To prevent the formation of plugs beyond the mixing chamber, water vapor must be injected in excess so that uncondensed bubbles of water vapor act as carriers for the heated fluid collection. .

This involves waste of water vapor and also gives rise to an irregular distribution of the fluid aggregates in the residence tubes arranged between the steam injector and the cooling stage which works by discharging under reduced pressure, and this causes Equivalent to irregular distribution of temperature.

Another important point is that irregular inputs into the retention tube cause pressure fluctuations, which can affect upstream of the injection nozzle and are reflected in temperature fluctuations of the injected steam.

The present invention is the result of an effort to find a device that does not have these deficiencies.

Furthermore, the device of the invention is a device for sterilizing and/or homogenizing a fluid product by injection of water vapor, comprising a straight pipe having an inlet end and an outlet end and a straight pipe for introducing the fluid product. a T-shaped body formed by a tubular arm, a steam injection nozzle located axially at the inlet end of the tube and opening into the mixing zone at the junction between the arm and the tube;
The downstream end of the injection nozzle has a conical surface that diverges downstream from the outlet opening of the passageway, and the upstream end of the discharge pipe has a conical surface that converges upstream with respect to the inlet opening of the passageway;
The upstream end of the discharge pipe projects into the downstream end of the nozzle, and these two ends direct the flow over a mixing zone located between them between the outlet opening of the nozzle passage and the inlet opening of the discharge pipe passage. The device as described above defines a conical passageway that converges in opposite directions.

A T-shaped body is attached at each end of the straight tube and at each end of the tubular arm;
It may include means for connecting it to a pipe of corresponding diameter, these means being formed either from threads or from bayonet catch elements.

The various elements can be fixed to the T-shaped body in different ways depending on their shape or their respective properties.

The steam injection nozzle is held around its upstream end by a shoulder that rests on a ledge formed in the inner wall of the inlet end of the tube.

The connecting element can be provided on the discharge pipe, ie in the form of a thread cut into the downstream end of the pipe (corresponding to a thread cut into the inner wall of the outlet end of the pipe).

The distance between pipe and nozzle can be adjusted easily and with high precision using this connecting element.

To use the device according to the invention, the inlet end of the tube is connected to a pipe for introducing water vapor under pressure, the outlet end thereof is connected to a retention tube, and the tubular arm is connected to a pipe for introducing water vapor under pressure. Can be connected to a pipe for introducing the product.

The retention tube can itself be connected to a cooling chamber or an expansion chamber by means of a back pressure valve.

It is advantageous to use a water vapor pressure at the nozzle tip that is sufficiently high to benefit from the advantages of a nozzle having an inner wall that converges downstream onto a short passage of constant cross-section that opens into the mixing zone at its outlet end.

This is due to the critical flow law, which states that for this type of nozzle, the flow rate of water vapor at the outlet end of the nozzle will reach its ultimate velocity from the moment the pressure at the inlet end of the nozzle exceeds approximately twice the pressure at the outlet end of the nozzle. (i.e., the speed of sound in water vapor), but does not exceed it.

The pressure prevailing in the retention tube may be maintained at a value somewhat above the saturated vapor pressure of water at the selected sterilization and/or incubation temperature.

Therefore, the water vapor pressure at the inlet end of the nozzle must be significantly higher than twice the pressure prevailing in the retention tube, so that the difference between the pressure at the outlet end of the nozzle and the pressure in the retention tube prevails in the retention tube. It will not be significantly affected by accidental fluctuations in pressure.

In this way, these fluctuations can affect upstream of the nozzle, but the flow rate and temperature of the injected steam remain constant.

The pressure at which the fluid product is injected into the delivery arm can be chosen within a range determined by the pressure prevailing in the retention tube and the pressure prevailing at the outlet end of the nozzle.

Given the prevailing critical flow conditions, the water vapor flow rate per cross-section of the outlet passage of the nozzle is known from the moment of fixing the value of the water vapor pressure prevailing at the inlet end of the nozzle.

Once you know the temperature and flow rate at which the fluid product is introduced into the equipment and the temperature at which you wish to sterilize the product, you can determine the amount of water vapor required;
It is therefore possible to accurately calculate the diameter of the nozzle to be used.

In this way it is possible to work efficiently under constant and well-defined conditions.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some specific examples of the device of the present invention will be briefly described with reference to the accompanying drawings.

The device shown in the figure consists of a T-shaped body formed by a straight tube, 1, and a tubular arm 2.

A steam injection nozzle 5 is arranged axially at the inlet end 3 of the tube.

A discharge vibro is arranged axially at the outlet end 4 of the tube.

The inner wall 11 of the nozzle 5 has a conical shape and extends downstream towards a passage 9 that opens through its outlet opening 8 into the mixing zone 12 at the junction between the arm 2 and the tube 1. converge towards.

The nozzle 5 is made of polytetrafluoroethylene.

T is made of stainless steel, and so is the discharge vibro.

The upstream end of the discharge pipe has a conical surface 31 that converges upstream over the inlet opening of the passageway 22 .

The downstream end of the injection nozzle has a conical surface 32, which widens downstream from the outlet opening of its passageway 9 and runs towards the upstream end of the vibro, so that these two ends A mixing zone 12 located between them the outlet opening of the nozzle passage and the inlet opening of the pipe passage
defines a conical passage 33 that converges in the upstream direction.

This embodiment of the device according to the invention therefore makes it possible to inject the liquid product to be sterilized into the steam jet countercurrently therewith and not in a perpendicular, ie parallel, flow.

This results in a shearing effect on the flow of the fluid product so that it becomes homogenized.

The vibro is fixed within the tube on the end 4 of the tube by an external thread 34 corresponding to the internal thread 38, which allows the distance of its exit from the nozzle to be adjusted with considerable precision.

In the embodiment shown, the pipe has an internal thread 35, the latter receiving a threaded ring 36 carrying a rupture tube 37 designed to enhance the homogenizing effect.

Ring 36 is perforated throughout the bottom of the rupture tube to allow passage of the sterile, homogenized fluid product.

However, this rupture tube 37 is not absolutely necessary to obtain homogenization and only plays a minor role.

To seal the device, screw the synthetic O-ring 39 onto the screw 3.
Place it between the upstream pipes 4 and 38.

This is held in place by a groove formed in the outer wall of the pipe.

In the embodiment shown here, it is the pipe itself that has the means of connection to the retention pipe.

The examples below illustrate the use of the device of the invention and also give the results of some comparative tests.

The percentages listed are weight percentages unless otherwise specified.

Example In the production of reconstituted whole milk from skim milk powder and butter oil, reconstituted skim milk containing 19.8% dry matter is first prepared and an equal amount of butter oil is mixed with it and thus obtained. The premix is emulsified to create a concentrated fleur-de-lis emulsion.

Next, 16% of the pre-emulsion and 84% of reconstituted skim milk are thoroughly mixed to obtain a final product of the required composition.

Premix at least 40°C using various equipment as described below.
Emulsify at a temperature of: 8 with a model LSR/80/61 FRYMA corn mill rotating at 2900 revolutions per minute with a power of 9 kW.

Premix (A1) for 30 Yu7 minutes in the mill, or 60
7 minutes (A2) are supplied by opening the stator by half and two revolutions per revolution, respectively.

■ Based on model TDLK3-55 toothed ring REACTRON mill.

Premixing is carried out by a partition placed at the entrance of the mill.

The mill is fed at a rate of 101/min (B1) or 201/min (B2).

0' By model 305 toothed ring 5UPRATON mill with 5400 rpm/rotation rotation.

10ky/premix prepared as described in B.
min (C1) or 20 kg/min (C2).

D 2900 rotation/rotation model 5ter i
By IM-II toothed ring BROGLI mill.

Prepare the premix as described in B.

10ky/min (Dl) or 20kg/min (B2) to the mill
).

According to an apparatus according to the invention of the type shown in FIG.

T consists of tubes and arms each having a diameter of 35 mm.

The nozzle passage has a diameter of 5 mm and a length of 10711 rIL,
It opens into a conical outlet with a 60° opening.

The steel pipe has an inlet passage of φ5m7IL and is 7mr long.
rt and fits into the flared end of the nozzle, so that a conical channel with an opening of 60° and a thickness of around 0.5 mm is free for the flow of the premix.

In this way, the premix is injected at high velocity into the water vapor jet exiting the nozzle passage and is then violently entrained into the inlet passage of the pipe.

Premix at a water vapor pressure of 1.1 or 3.2 bar at the nozzle tip (this causes a temperature increase of 40 to 90 °C)
It is fed at a rate of 5 kg/min (El) or 10 kg/min (B2).

Each pre-emulsion is then thoroughly mixed with the required percentage of reconstituted skim milk in a conventional mixer rotating at approximately 300 revolutions per minute for several minutes.

The fineness of the suspended butter oil droplets is then observed under a microscope, after which the separation of the cream is determined as a function of time.

The results shown in the following table were obtained. Cream separation is indicated by the volume of separated cream.

Table (continued) Case Average dimension of oil sphere Equipment φ (μ) Al 4-12 FRYMAA2
8-15 FRYMAB 1 4
-8 REACTBONB2 4-8
REACTRONC13-55UPRATO
N C23-55IJPRATON DI 10-20 BROGLID2
10-20 BROGLIE13-6
Apparatus of the present invention E25-8 Apparatus of the present invention As described above, the results obtained using the apparatus of the present invention show that although this apparatus is the simplest in structure, the cheapest, and the easiest to use, it is among the best. And it's also the best.

[Brief explanation of the drawing]

FIG. 1 is a 1:1 scale cross-sectional view of an embodiment of a device contemplated for sterilization and/or homogenization of fluids of varying viscosities.

Claims (1)

[Claims] 1 In an apparatus for sterilizing and/or homogenizing fluid products by injection of water vapor, a T-shaped body formed by a straight tube with an inlet end and an outlet end and a tubular arm for introducing the fluid product , a steam injection nozzle located axially at the inlet end of the tube and opening into the mixing zone at the junction between the arm and the tube, the downstream end of this injection nozzle having a cone extending downstream from the outlet opening of its passage. the upstream end of the discharge pipe has a conical surface that converges upstream with respect to the inlet opening of the passageway, the upstream end of the discharge pipe projects into the downstream end of the nozzle, and the upstream end of the discharge pipe has a conical surface converging upstream with respect to the inlet opening of the passage, the upstream end of the discharge pipe projects into the downstream end of the nozzle, and the upstream end of the discharge pipe has a The above device defines a conical passage converging against the flow over the mixing zone located between the outlet opening of the nozzle passage and the inlet opening of the discharge pipe passage.