RU2322811C2 - Apparatus for producing of sterilized milk - Google Patents

Abstract

FIELD: milk industry.

SUBSTANCE: apparatus has closed casing wherein a number of cassettes with ultraviolet radiation lamps are mounted. Flat reactors are positioned between each two cassettes, said reactors being formed as flat quartz tubes having width less than 1 mm. Cavity of tube is aligned with inlet and outlet reservoirs. Outlet reservoir is connected through branch pipe to inlet reservoir of reactor subsequent in the row of reactors. Inlet reservoir of first reactor is connected to milk feeding pipeline and outlet reservoir of terminating reactor is connected to aseptic packaging pipeline.

EFFECT: reduced consumption of power for milk sterilizing process.

2 cl, 1 dwg

Description

The invention relates to the dairy industry and can be used for continuous sterilization of milk at dairies, as well as for periodic sterilization of small batches of milk directly at dairy farms.

There is a method of sterilizing milk according to a / c SSSSR No. 340392, which consists in pre-cleaning it from mechanical impurities, normalizing the fat content, heating to 70-80 ° C, short-term sterilization at a temperature of at least 140 ° C, followed by cooling of the milk and packaging under aseptic conditions.

The disadvantage of this method is that the milk in the sterilization process is heated, first preliminary, and then although briefly, with a sufficiently high temperature. This leads, firstly, to an increase in energy costs during in-line sterilization, and secondly, to a decrease in the palatability of milk.

The proposed method is as follows.

After purification from mechanical impurities and normalization, milk enters first into an ultrasonic homogenizer, and then into a sealed reactor, where several cycles of its treatment with ultraviolet (UV) radiation are carried out, with stirring after each cycle, and then packaged under aseptic conditions. In this case, milk cooling is not required.

When sterilizing milk with UV radiation, energy costs are significantly less. UV radiation does not affect the taste of milk and at the same time reliably kills bacteria and viruses in milk. It should be noted that sterilizing milk with UV radiation is not a new idea, for example, see the work of Wesser R. Technology for the production and processing of milk. - M .: Kolos, 1971. However, due to the fact that the effective penetration of UV radiation into milk is possible to a small depth, up to 0.1 mm, there are difficulties in implementing this idea, which impede the widespread use of milk sterilization with UV radiation in industry , and the processing of milk with UV radiation in one cycle leads to an increase in the dimensions of the installation and a decrease in its productivity.

The processing of milk with UV radiation in the proposed method is carried out for several cycles with stirring between cycles, which allows you to collect the necessary dose of UV radiation for destruction of bacterial DNA - 40 mJ, and mixing allows you to process a new layer of milk each time and thus reliably sterilize all milk. The number of cycles is determined empirically when developing a specific installation. Preliminary homogenization of milk in an ultrasonic homogenizer allows increasing the depth of UV radiation penetration into milk by reducing the shadow effect of fat inclusions. In addition, UV treatment of milk should be carried out in sealed quartz reactors, since when using UV radiation with the most effective wavelength of 254 nm, a large amount of ozone will inevitably form in the ambient air, which will lead to the oxidation (souring) of milk.

A prototype of a device for implementing this method can be a device for processing liquid in a thin layer, a / c USSR 7999704. This device contains a cylindrical tank, separated from the housing by a layer of insulating material, a receiving chamber, a float distributor, a radiation source, with sockets outside the cylindrical tank and branch pipe for a conclusion of liquid. The disadvantages of this device is that, firstly, the liquid is processed in one cycle, and reliable treatment of the liquid, in particular, complete sterilization is possible only at low flow rates or an extended zone, up to several meters, which will not allow to solve the issue of its industrial application. Secondly, emitters (bactericidal lamps) are installed without protective covers and if they are destroyed, harmful substances may enter the liquid. In addition, the emitters are surrounded by air that is in contact with the liquid being treated, which will inevitably lead to its oxidation by ozone. Thirdly, the above diagram of the installation of emitters in a cylindrical case, since the middle of the emitters is quite far from the liquid being treated, and at the ends there is a region of ineffective radiation due to its fall at an angle to the surface being treated.

The aim of the present invention is to remedy these disadvantages, as well as the creation of an economical and reliable installation of in-line sterilization of milk with high performance.

This goal is achieved by the fact that, in a closed reactor vessel, a series of cassettes with UV lamps are mounted, and flat reactors are made between each two cassettes in the form of a flat quartz tube, the cavity of which is connected to the inlet and outlet reservoirs, and the outlet reservoir is connected by a pipeline with an inlet tank of the next reactor in the row, the inlet tank of the first reactor connected to the milk supply line, and the outlet tank of the last reactor with the aseptic packaging line. The cavity width in a flat reactor tube is not more than 1 mm. The sealed housing of the device is made of opaque material and is equipped with an exhaust fan and a filter for ozone, and at the walls of the housing parallel to the lamps, a screen reflecting UV radiation is installed. The homogenizer is installed in a separate housing and is connected to the inlet pipe of the first reactor.

The drawing shows a diagram of the proposed device.

In a sealed reactor vessel 1, cassettes 2 with bactericidal UV radiation lamps 3 are installed. The number of cassettes 2 per cartridge is greater than the number of processing cycles. Between the cassettes 2 are installed flat quartz reactors 4, the number of which is equal to the number of processing cycles. Each reactor 4 is connected to the upper (output) tank 5 and the lower (input) tank 6. The upper 5 and lower 6 tanks of the adjacent reactors 4 are interconnected by pipelines 7. The lower tank 6 of the first reactor in the row 4 has an inlet pipe 8, and the upper tank 5 of the last in the reactor row 4 is the outlet pipe 9. At the walls of the housing 1, parallel to the cassettes 2 with lamps 3, screens 10 are installed that reflect UV radiation. The housing 1 is equipped with a fan 11 and an ozone filter 12. The inlet pipe of the first reactor 8 is connected to a homogenizer 13, which is connected by a pipe 14 to the milk supply line.

After purification from mechanical impurities and normalization, the milk to be processed through the nozzle 14 enters the homogenizer 13, and then through the nozzle 8 into the inlet tank 6 of the first reactor in the row 4. Since the volume of the reactor 4 is less than the volume of the inlet tank 6, disturbances in the milk relax and in the reactor 4, the flow of milk becomes laminar. Passing between two plane-parallel walls in a gap of not more than 1 mm, the milk is exposed to UV radiation generated by lamps 3 installed in cassettes 2. Reflection of UV radiation from screens 10 enhances the sterilizing effect. After leaving the reactor 4, milk enters the outlet tank 5, and from it through the pipe 7 to the inlet tank 6 of the next reactor 4 in a row. Thus, the milk passes sequentially through all the reactors 4, that is, it gains the required number of UV treatment cycles. Mixing of milk occurs in the output tanks 5 of the reactors 4 (the flow rate in the reactors 4 is greater than in the output tanks 5) and in the pipelines 7. The output tank 7 of the latter in the reactor row 4 has a pipe 9 for connecting the unit to the aseptic milk spill line. The sealed housing 1 is equipped with a fan 11 and a filter 12 for pumping and degassing ozone generated by the operation of UV lamps 2 in the air surrounding them. Degassing of ozone is necessary, since its large dose in the room is harmful. Screens 10 mounted parallel to the cassettes 2 at the walls of the housing 1 reflect UV radiation and enhance the sterilization effect in extreme reactors 4 by 30-60%.

In the proposed installation scheme for milk sterilization, bactericidal lamps 3 are installed most rationally - the entire radiation surface is parallel to the plane of the reactor 4 and, in addition, they can be installed at a minimum distance from the plane of the reactor 4. The reactor 4 is made of quartz glass, which passes UV better than other materials -radiation, and its irradiation from two sides allows you to double the theoretical depth of the processed layer of milk, which will reduce the number of reactors 4. The width of the slit of the reactor 4 - less than 1 mm allows achitelno increase the throughput capacity of the reactor 4 and optimize the process. Since during processing the milk does not come in contact with the air surrounding the bactericidal lamps 4, ozone is not formed in the reactor 4 and the milk is not oxidized. The flow of milk during the transition from reactor 4 to adjacent reactor 4 (reactor 4 — output tank 5 — pipeline 7 — inlet tank 6) due to the difference in flow cross sections, and, consequently, speeds, is turbulent and mixes well. In the next reactor 4, other layers of the milk stream will undergo the most efficient UV treatment (near the walls of the reactor 4). Reliable sterilization of milk will be ensured by 3-5 cycles of milk processing by UV radiation, i.e. 3-5 reactors, which will create a small-sized installation. Housing 1 must be well ventilated, for which purpose fan 11 and a filter (neutralizer) 12 are used. To neutralize ozone, copper chips can be used as filler for filter 12.

It is proposed to use the ultrasonic homogenizer RUZ 03-12 or RUZ 03-30 as a homogenizer 13 in the installation (see the journal "Food Processing Equipment in Russia", No. 12-1, 2006). Preliminary homogenization allows you to grind fatty inclusions in milk, that is, to make it more homogeneous, which will increase the efficiency of its treatment with UV radiation. The unit has small dimensions and can be used on large dairy farms.

The proposed method of sterilization of milk and the installation for its implementation can be successfully used for sterilization of other non-transparent and opaque liquids, such as beer, whey, etc.

Claims (2)

1. A device for the bactericidal treatment of milk, characterized in that a series of cassettes with UV lamps are mounted in a closed case, and flat reactors are installed between each two cassettes, made in the form of a flat quartz tube with a width of not more than 1 mm, the cavity of which is connected to the input and output tanks, the output tank being connected by a nozzle to the input tank of the next reactor in the row, the input tank of the first reactor is connected to the milk supply line, and the output tank of the latter is connected to the a line septic packaging. 2. The device for the bactericidal treatment of milk according to claim 1, characterized in that the sealed housing of the device is made of opaque material and is equipped with an exhaust fan, the outlet of which has an ozone filter, and screens reflecting UV radiation are installed at the walls of the housing parallel to the lamps .