RU2431408C1 - Plate vacuum-evaporator apparatus - Google Patents

Abstract

FIELD: food industry.

SUBSTANCE: invention is intended for application in canning industry in the process of production of pureed concentrates of fruit and vegetables. The plate vacuum-evaporator apparatus contains a vacuum chamber, vertical heat-exchange plates positioned parallel inside it, a feeding and a discharging devices, separators for capture of minute drops of the product from vapours being released. The plates have a wave-shaped profile, the plates are designed to be hollow with horizontal bafflers positioned inside them for ensuring zigzag movement of the heat carrier and are equipped with nozzles for supply and withdrawal of hot and exhaust heat carrier accordingly. A device for delivery of the original product is positioned above them mounted so that to enable relocation within the vertical plane assisted with pneumatic cylinders. A vertical chain conveyor is mounted between each pair of heat-exchange plates. On the conveyor chain links axes with flexible horizontal scrapers are incrementally located; the scrapers are arranged so that to enable touching the heat-exchange plates surface.

EFFECT: invention ensures fruit-and-vegetable puree quality enhancement, the evaporation process intensification, energy costs reduction, performance enhancement.

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Description

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

The closest in its technical essence and the achieved effect is the installation for the concentration of fruit and vegetable purees [patent No. 2359462, IPC A23B 7/00, A23B 4/044, No. 2008111758/13. Ostrikov A.N., Vertyakov F.N., Veretennikov A.N., Dorokhin S.V. Claim 03/27/2008. Publ. 06/27/2009. Bull. No. 18], containing a cylindrical body, inside of which 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 the finished product due to the short-term course of the concentration process by intensive mixing and more uniform processing due to the use of a rational design of flexible scrapers and undulating surfaces of heat exchanger plates, reducing material and energy resources, increasing productivity by switching to continuous operation.

The technical task of the invention is achieved by the fact that in a plate vacuum evaporator containing a vacuum chamber, a loading and unloading device, it is new that vertical heat exchange plates having a wavy profile and parallel to them are arranged inside the vacuum chamber of rectangular cross section for supplying the original product, installed with the possibility of movement in the vertical plane with the help of pneumatic cylinders and representing a pipe with horizontal slots, which include the upper edges of the heat exchanger plates, the heat exchanger plates being hollow with horizontal partitions located inside to provide a zigzag motion of the heat carrier and equipped with nozzles for supplying hot and discharging waste heat carrier, a vertical chain conveyor is installed between each pair of heat transfer plates, on the chain links of which there are axes with a certain pitch with flexible horizontal scrapers, which are installed with the possibility of touching the surface of the heat exchange plates Stin, in the upper lid of the vacuum chamber there are pipes for the removal of evaporated water vapor, which are connected by a collector to the vacuum pump, at the ends of the pipes located inside the vacuum chamber, there are separators for catching the smallest drops of product from the vaporized vapor, and in the lower part - chambers under the plates are equipped with an unloading chamber with a screw conveyor located in it and an unloading nozzle with a vacuum lock gate.

The technical result of the invention is to improve the quality of fruit and vegetable purees, the intensification of the evaporation process by increasing the area of the heat exchange surface used for boiling mashed potatoes, reducing energy resources due to the rational use of heat carrier energy, increasing productivity due to the transition to continuous operation.

Figure 1 shows a longitudinal section of a plate vacuum evaporator, figure 2 is a top view of a plate vacuum evaporator, figure 3 is a three-dimensional image of a plate vacuum evaporator, figure 4 is a three-dimensional image of a heat exchange plate and a vertical chain conveyor.

Lamellar vacuum evaporator consists of a vacuum chamber 1 of rectangular cross-section, inside of which are parallel vertical heat transfer plates 2 having a wave-like profile (Figs. 1, 2 and 3). The heat exchange plates 2 are hollow with horizontal partitions 3 located inside to provide a zigzag motion of the coolant and are provided with a lower pipe 4 for supplying hot coolant and an upper pipe 5 for removing the spent coolant.

Hot heat carrier, zigzag moving from bottom to top along the internal channels of the plates 2, heats the left and right working surfaces of the plates 2. The expediency of installing horizontal partitions 3 is due to the following consideration. To ensure the normal downward flow of the film of mashed potatoes on the heated left and right working surfaces of the plates 2 under the action of gravity, it is necessary that the temperature of the film increases as it flows down. This is due to the fact that in the film of mash flowing down on the heated left and right working surfaces of the plates 2, due to the vaporized water vapor from it, the solids content increases and, consequently, the viscosity of the mash constantly increases. In this regard, this film of the product as moisture evaporates and viscosity increases poorly flows down the heated left and right working surfaces of the plates 2 under the action of gravity. An increase in temperature will reduce the viscosity of the mashed film to a certain limit. Therefore, to smoothly increase the temperature of the wall from top to bottom, a zigzag motion of a heat carrier heating the left and right working surfaces of the plates 2 from bottom to top was organized due to horizontal partitions 3 (Fig. 1).

Above each heat exchanger plate 2, a device 6 for supplying an initial product is installed, representing interconnected pipes 19 with a horizontal slot, which include the upper edges of the heat exchanger plates 2. The device 6 is mounted with the possibility of moving in a vertical plane using pneumatic cylinders 17. For this, pneumatic cylinders 17 using vertical rods 18 are rigidly connected to the pipes 19 of the device 6 for supplying the original product (figure 4).

In the lower part of the vacuum chamber 1, under the plates 2, an unloading chamber 7 is installed with a screw conveyor 8 located in it and an unloading pipe 9 with a vacuum lock gate 10.

In the upper cover of the vacuum chamber 1 there are nozzles 11 for removing evaporated water vapor, which is connected by a collector 12 to a vacuum pump (not shown in Figs. 1 and 3).

At the ends of the nozzles 11 located inside the vacuum chamber 1, there are separators 13 for trapping the smallest drops of the product, carried away by evaporated water vapor, sucked off by the vacuum pump through the nozzles 11.

Between each pair of heat exchanger plates 2, vertical chain conveyors 14 are installed, on which axes 15 with flexible horizontal scrapers 16, which are installed with the possibility of touching the surface of heat exchanger plates 2, are located with a certain step.

The vertical chain conveyors 14 are equipped with a device 20 for regulating the tension of the chains, which is a support plate 21 with springs 22 and telescopic bushings 23. The conveyors 14 have a common adjustable drive 24, which can provide both continuous and intermittent with intermittent stands modes of movement of the conveyors 14.

The walls of the vacuum chamber 1 are thermally insulated to reduce heat loss to the environment.

Lamellar vacuum evaporator operates as follows.

The drive of the vacuum pump (not shown in FIGS. 1 and 3) is turned on, connected by a collector 12 to the nozzles 11 for removing evaporated water vapor, and a predetermined vacuum value is created in the vacuum chamber 1. At the same time, through the lower nozzles 4, inside the heat exchange plates 2, a hot heat carrier with a predetermined temperature is supplied. Since horizontal partitions 3 are installed between the left and right walls of the plates 2, the coolant is given a zigzag motion, which contributes to a more efficient use of its energy and a smooth increase in the temperature of the heated surface of the walls of the plates 2 from top to bottom. The spent coolant is removed through the upper nozzles 5 (Fig.3).

Next, an adjustable drive 24 is turned on, which drives the vertical chain conveyors 14. Then, with the help of pneumatic cylinders 17, the device 6 is moved in a vertical plane to set a predetermined gap between the pipes 19 and the upper edge of the heat exchanger plates 2. Moreover, with a larger gap, a greater product flow is achieved from pipes 19 to the working surfaces of the heat transfer plates 2, and with a smaller gap, a smaller supply of product from the pipes 19 to the working surfaces of the heat transfer plates 2 (Fig. 4).

The puree is evenly distributed on the heated left and right surfaces of the plates 2. Due to the zigzag movement of the coolant inside the plates 2, the temperature of the heated left and right surfaces of the plates 2 gradually increases from top to bottom.

Let us dwell in more detail on the nature of the movement of flexible horizontal scrapers 16. When moving vertical chain conveyors 14, on the chain links of which axes 15 with flexible horizontal scrapers 16 are located with a certain step, touching the right working surface of the plates 2 move from the upper to the lower position. And, conversely, in contact with the left working surface of the plates 2, they move from bottom to top.

To regulate the tension of the chains, the device 20 compensates for the temperature extension of the chain links due to the springs 22 and telescopic sleeves 23.

Draining under the influence of gravity and the influence of flexible horizontal scrapers 16 on the heated left and right surfaces of the plates 2, the puree heats up, boils and moisture evaporates from it in the form of steam, which is removed through the nozzles 11 into the collector 12.

When moving, the product temperature is aligned throughout the layer, preventing it from burning on the heated surface of the left and right walls of the plates 2. Flexible horizontal scrapers 16 move the product layers on the heated surface of the left and right walls of the plates 2 down to the discharge chamber 7 with the screw conveyor 8 in it and an unloading pipe 9 with a lock vacuum lock 10. Then the adjustable drive 25 is turned on, which drives the screw conveyor 8.

Evaporating water vapor captures the smallest particles of mashed potatoes. To trap the smallest drops of the product, carried away by evaporated water vapor, sucked off by the vacuum pump through the nozzles 11, a separator 13 is designed. The product particles flowing around the separator 13 are collected on its surface, coarsened and then fall down into the vacuum chamber 1.

Concentration of fruit and vegetable purees is carried out by evaporating part of the moisture contained in the puree product at low boiling points due to the use of vacuum (supported by a vacuum pump connected to the collector 12) due to conductive heating from the heated surfaces of the left and right walls of the plates 2. Main the purpose of heating is to bring the puree-like product to a given final moisture content by evaporating excess moisture under a given vacuum at a given temperature. The duration and temperature of evaporation should be selected depending on the type of fruit and their degree of maturity. In this case, the duration of evaporation is controlled by the speed of movement of the chain conveyors 14, and the temperature of evaporation is controlled by the temperature and flow rate of the coolant supplied through the lower nozzles 4.

When the desired puree is reached, the mashed potatoes are unloaded from the chamber 7 using the screw conveyor 8 located in it through the discharge pipe 9 with a vacuum lock gate 10.

Using the proposed plate vacuum evaporator allows you to:

- to improve the quality of fruit and vegetable purees by eliminating the multi-stage and long processing of the product and the use of soft technological modes of boiling at low boiling points due to the use of vacuum;

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

- to intensify the process of obtaining the finished product due to the use of rational movement of the product from top to bottom of the apparatus together with maintaining the optimal temperature regime of heating;

- increase productivity due to the transition to a continuous mode of operation.

Claims (1)

A plate vacuum evaporator containing a vacuum chamber, a loading and unloading device, characterized in that in the rectangular vacuum chamber there are parallel vertical heat transfer plates having a wavy profile, and above them is a device for supplying the initial product, installed with the possibility of movement in the vertical plane with the help of pneumatic cylinders and which is a pipe with horizontal slots, which include the upper edges of the heat transfer plates, and heat transfer the th plates are hollow with horizontal partitions located inside to provide a zigzag motion of the heat carrier and are equipped with nozzles for supplying hot and discharging waste heat carrier, a vertical chain conveyor is installed between each pair of heat transfer plates, on the chain links of which there are axes with flexible horizontal scrapers with a certain pitch, which installed with the possibility of touching the surface of the heat exchanger plates, a nozzle is located in the upper cover of the vacuum chamber and for the removal of evaporated water vapor, which are connected by a collector to the vacuum pump, at the ends of the nozzles located inside the vacuum chamber, there are separators for trapping the smallest drops of product from the vaporized vapor, and in the lower part of the vacuum chamber under the plates there is an unloading chamber with in it with a screw conveyor and an unloading pipe with a lock vacuum lock.

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