RU2477969C1 - Vacuum evaporator - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to food industry. Vacuum evaporator comprises vertical cylindrical two-body housing accommodating mixer and spray nozzles to force initial product in. Evaporators is divided by separator into two, top and bottom, chambers. Evaporator top cover houses branch pipes to discharge vapors from aforesaid chambers. Every chamber accommodates rotary spray nozzles to force initial product in. Note here that product in bottom chamber is sprayed from bottom to top while in top chamber it is sprayed radially. Top spray nozzles are equally spaced on annular hill-like chamber lateral surface, said chamber being driven by motor via coupling. Bottom chamber conical part is communicated with pump to feed pre-thickened suspension into rotary spray nozzles in top chamber. Annular trough is arranged on bottom chamber inner cylindrical surface to collect and removed thickened suspension from top chamber.

EFFECT: higher quality of finished product.

4 dwg

Description

The invention relates to equipment for the canning industry, and in particular to vacuum evaporators for the production of puree concentrates from fruits and vegetables.

The closest in technical essence and the achieved effect is the installation for concentrating fruit and vegetable purees (Pat. No. 2359462, IPC A23B 7/00, A23B 4/044, No. 2008111758/13. Ostrikov AN, Vertyakov F.N., Veretennikov A.N., Dorokhin S.V. Declaration of March 27, 2008, Publ. June 27, 2009, Bull. No. 18), comprising a housing, inside of which there is a vertical hollow shaft with a stirrer.

The disadvantages of the installation for concentrating fruit and vegetable purees are the low quality of the finished product due to the prolonged boiling of the feedstock; significant material and energy costs; low productivity due to periodic operation, and a significant process time.

An object of the invention is to improve the quality of finished products due to the short-term course of the concentration process by finely dispersed spraying and more uniform processing due to the use of a rational design of mixers, reduction of material and energy resources, increased productivity due to the intensification of the evaporation process and the transition to a continuous mode of operation.

The technical task of the invention is achieved by the fact that in a vacuum evaporator containing a vertical cylindrical two-body housing with a mixing device located inside and spray nozzles for inputting the initial product, it is new that the vacuum evaporator is divided by a separator into two chambers: upper and lower, in the upper cover of the vacuum apparatus, nozzles are installed to remove the vapor vaporized from the chambers, rotating spray nozzles are installed in each chamber to introduce the initial product, etc. why the product is sprayed in the lower chamber from the bottom up, and radially in the upper chamber, the upper spray nozzles are located with equal steps on the side surface of the annular toroidal chamber, which is rotationally driven through the coupling from the electric motor, the conical part of the lower chamber is connected to the pump, which it feeds a pre-thickened suspension through a pipeline to rotating spray nozzles in the upper chamber, and is installed on the inner cylindrical surface of the lower chamber to tsevoy gutter for collection and subsequent removal flowing on the vertical wall of thickened suspension from the upper chamber.

Figure 1 presents a three-dimensional image of a vacuum evaporator; figure 2 - image of a rotating spray nozzles for input of the original product into the upper chamber; figure 3 is a diagram of the movement of the concentrated product through the chambers of the vacuum evaporator; figure 4 is a three-dimensional image of the mixer.

The vacuum evaporation apparatus (Fig. 1) consists of a housing 1 and an upper cover 2. In the upper cover 2, nozzles 5 and 6 are installed to remove evaporated vapors that are connected by a pipeline to a vacuum pump (not shown in Fig. 1). The housing 1 of the vacuum apparatus is equipped with a jacket 7 with a pipe 8 for supplying a hot coolant and a pipe 9 for removing the spent coolant. Inside the vacuum apparatus, a combined mixer 3 is installed, on which there are three types of scrapers of different configurations: sickle-shaped 20 and 22 and ploughshape 21 (Fig. 4). Share-shaped scrapers 21 are intended for cleaning the inner cylindrical surface of the lower chamber 26 and moving the product to the conical part of the lower chamber 26. Crescent-shaped scrapers 20 are used to clean the conical inner surface of the lower chamber 26 and moving the product to the discharge opening connected to the pipe 13. Crescent-shaped scrapers 22 are intended for cleaning the surface of the separator 25 and moving the product to the inner cylindrical surface of the lower chamber 26. The combined mixer 3 is fixed on shafting in the bearing bearings 4 and 19 of the shaft 23 (figure 4).

The vacuum apparatus consists of two chambers: the lower 26 and the upper 27, separated by a separator 25. The separator 25 does not contact the inner cylindrical surface of the lower chamber 26: there is a gap between the outer edge of the separator 25 and the inner cylindrical surface of the lower chamber 26 so that the product flowing down from the surface of the separator 25 was applied with a thin even layer with a crescent-shaped scraper 22 along the inner cylindrical surface of the chamber 26. At the bottom of the chamber 26, nozzles 11 are installed, the product is supplied to is carried out through a pipe 12 passing through the hollow shaft of the mixer 3. The product from the lower chamber 26 through the pipe 13 is pumped by the pump 14 to the upper chamber 27.

An annular toroidal chamber 28 is installed in the upper chamber 27 on the nozzle 6, on the lateral surface of which spray nozzles 15 are radially arranged with equal pitch (Fig. 2). To provide tightness of the annular toroidal chamber 28 and to prevent product leakage from it, it is equipped with mechanical seals 17. The annular toroidal chamber 28 is rotationally driven by the electric motor 16 through the coupling 29. For a more uniform supply of the product to the nozzles 15 inside the nozzle 6 opposite the annular toroidal chamber 28 is fixed a hollow ring 18 connected to the pipe 13. The product from the hollow ring 18 enters the annular toroidal chamber 28 to the nozzles 15.

The concentrated product, flowing down the vertical side wall of the vacuum apparatus, enters the annular groove 10 and is discharged from the apparatus through the pipe 24.

Vacuum evaporator operates as follows.

The drive of the vacuum pump (not shown in Fig. 1) is connected, connected to the nozzles 5 and 6, and a predetermined vacuum value is created in the chambers 26 and 27. At the same time, a hot coolant with a predetermined temperature is supplied to the jacket 7 through the pipe 8, heating the inner side wall in chambers 26 and 27.

Next, an adjustable drive (not shown in FIG. 1) is turned on, which drives the agitator 3. The electric motor 16 is also turned on, which rotates the nozzle 15.

Then, the initial fruit or vegetable puree heated to a predetermined temperature by the injection pump (not shown in FIG. 1) is supplied through the pipe 12 to the rotating nozzles 11.

Due to the design of the spray nozzles 11, the product (fruit or vegetable puree) is sprayed in the form of finely divided droplets having a bell-shaped shape (stage I in figure 3). After the puree mass exits from the spray nozzles 11, as a result of a sharp drop in temperature and pressure, a finely dispersed spraying of the product occurs, accompanied by instant evaporation of moisture contained in the puree in an overheated state [Ostrikov A.N. Heat transfer during evaporation of steam from a dispersed stream of fruit and vegetable purees [Text] / A.N. Ostrikov, F.N. Vertyakov // Vestnik AGAU. - 2009. - No. 4 (54). - S.65-69]. The decomposition of a jet of mashed potatoes leaving the nozzles 11 into separate drops occurs under the combined action of cavitation phenomena that arise as a result of oscillatory processes that accompany the flow of the mashed potatoes before spraying, and under the influence of turbulent pulsations that lead to the separation of individual particles of the mashed potatoes. When substantiating the choice of nozzle design 11 and the spraying mode, they were guided by the following consideration: it was necessary to choose such a trajectory to provide the maximum possible range of their flight to ensure the required time for explosive evaporation of superheated moisture from the puree due to pressure drop [Vertyakov, F.N. Production of concentrated fruit and vegetable purees [Text] / F.N. Vertyakov A.N. Ostrikov. - Orenburg: IPK GOU OGU, 2009. - 452 p.].

Then, drops of fruit or vegetable puree settled on the surface of the conical part of the housing 1, forming a product film, which, with the help of sickle-shaped scrapers 20, mounted on the mixer 3, moved to the discharge opening connected to the pipeline 13. The sickle-shaped scrapers 20 not only move the product to the pipeline 13 , but also mix it intensively, while providing additional evaporation of moisture from the product, because the inner surface of the chambers 26 and 27 is heated using a shirt 7 (figure 4). Moreover, due to additional heating of the product from the surface of the conical part of the housing 1, additional evaporation of moisture from the product occurs.

The water vapor evaporated from the puree in the lower chamber 26 is removed through a pipe 6 connected to a vacuum pump (not shown in FIG. 1).

Next, the product through a pipe 13 is pumped by a pump 14 into an annular toroidal chamber 28, on the lateral surface of which spray nozzles 15 are radially arranged with equal pitch (Fig. 2).

Rotating by means of an electric motor 16 and clutch 29, the spray nozzles 15 spray the product (fruit or vegetable puree) in the form of finely divided droplets (stage II in figure 3). Moreover, as a result of a sharp difference in temperature and pressure, finely dispersed spraying of the product occurs, accompanied by instant evaporation of moisture contained in the puree in an overheated state [Vertyakov F.N. Production of concentrated fruit and vegetable purees [Text] / F.N. Vertyakov, A.N. Ostrikov. - Orenburg: IPK GOU OGU, 2009. - 452 p.]. The shape and design of the nozzles 15 provided a uniform spraying mode throughout the chamber 27. It is necessary that the droplets have such a trajectory as to ensure the maximum possible range of their flight to provide the required time for explosive evaporation of superheated moisture from the puree due to pressure drop.

Then drops of fruit or vegetable puree settled on the surface of the cylindrical part of the housing 1, forming a product film, gradually flowing down under the action of gravity (stage III in figure 3). When the puree droplets came in contact with the heated surface, the puree film flowing down heated up and the moisture from the puree evaporated due to the thermostatically controlled inner wall of the vacuum evaporator.

The share-shaped scrapers 21 mounted on the mixer 3 are cleaned and gradually smoothly move down the layer of vegetable or fruit puree.

Crescent-shaped scrapers 22 mounted on a mixer 3 are designed to remove the product from the upper surface of the separator 25 and apply the product with a thin even layer along the inner cylindrical surface of the chamber 26.

The water vapor evaporated from the puree in the upper chamber 27 is removed through nozzles 5 connected to a vacuum pump (not shown in FIG. 1).

The concentrated product (condensed suspension), flowing down the vertical side wall of the lower chamber 26, enters the annular groove 10 and is removed from the apparatus through the pipe 24 for further processing.

Using the proposed vacuum evaporator allows

- to improve the quality of fruit and vegetable purees due to the short-term course of the concentration process by finely dispersed spraying and more uniform processing due to the use of rational design of spiral belt mixers, as well as the use of soft technological modes of boiling at low boiling temperatures due to the use of vacuum;

- reduce material costs due to the elimination of auxiliary and transshipment operations;

- increase productivity due to the intensification of the evaporation process and the transition to a continuous mode of operation.

Claims (1)

A vacuum evaporation apparatus comprising a vertical cylindrical two-body housing with a mixing device and spray nozzles located inside for introducing the initial product, characterized in that the vacuum evaporation apparatus is divided into two chambers by a separator: the upper and lower chambers, and nozzles are installed in the upper cover of the vacuum apparatus removal of vapor vaporized from the chambers, rotating spray nozzles are installed in each chamber to introduce the initial product, and the product is sprayed in the lower chamber from the bottom to the top, and in the upper chamber - radially, the upper spray nozzles are located with equal pitch on the side surface of the annular toroidal chamber, which is rotationally driven through the coupling from the electric motor, the conical part of the lower chamber is connected to the pump, which feeds the pre-thickened suspension through the pipeline on the rotating spray nozzles in the upper chamber, and on the inner cylindrical surface of the lower chamber an annular chute is installed for collection and subsequent removal second vertical wall thickened suspension from the upper chamber.

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