RU2518645C2 - Device to produce ice - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: proposed device can be used in all types of ice generators used in food industry, pharmacology, agriculture, medicine, etc, wherein ice is chipped off from smooth cylindrical, flat of pother ice forming surfaces. This device comprises even number of spiral edges composed by different-shape knives arranged discretely there along. Sized of knife bases, the distance between them and cutting edges are equal. Said knives are arranged on spirals so that every knife of cutting edge is located opposite the spacing between knives of the next and previous cutting edges.

EFFECT: power savings.

2 cl, 1 tbl, 5 dwg

Description

A device for producing ice can be used in all types of ice machines used in the food industry, pharmacology, agribusiness and medicine, in which ice is chipped off from smooth cylindrical, flat and other types of ice-forming surfaces.

Various types of ice machines are known for producing process and food ice. In particular, block, tiled, loose. The last, most commonly used type of ice includes: fine-grained, scaly, granular and snowy [1].

The studies, as well as the work of other specialists [2-4], showed that the correct choice of ice type for refrigeration processing of products provides a reduction in cooling time, energy consumption, and also improves product quality. At present, flake ice generators consisting of a cylindrical evaporator, the water purified from mechanical impurities, are supplied to the inner or outer surface of it [5]. The resulting ice is chipped with a special tool. It is known that the size of the plates of ice particles depends on the speed of movement of the cutting tool relative to the ice-forming surface. However, these changes are insignificant and are limited by the time of ice freezing. The production of ice in drum-type ice machines consists of two stages: freezing water on its ice-forming surface and chipping off the obtained ice using scrapers or cylindrical (finger) mills [1, 5]. Thin layers of ice up to 1 mm are chipped with scrapers moving along the cylindrical ice-forming surface of the ice maker, which can be located both vertically and horizontally. The disadvantages of scrapers include a sharp increase in the load on the geared motor and energy consumption for chipping ice with an increase in its thickness over 1-2 mm and a decrease in temperature below minus 1.5-2 ° C.

Cylindrical milling cutters with continuous cutting edges mounted parallel to the axis of the ice maker drum and almost in contact with its surface are most widely used for chipping ice with a thickness of more than 2 mm. However, the process of chipping ice with a thickness of 5 mm to 7 mm and a temperature of the latter minus 5-7 ° C with the use of these mills is deteriorated due to the uneven distribution of efforts from the cutting edge of the milling cutter over the surface of the ice being chipped. This leads to sharp "jumps" of the cutter up to the operation of the protective device from overloads. As a result, the alignment is broken, the bearings are destroyed, the load on the gear motor increases and the energy costs increase. The particle size and the dispersion of their parameters of hundreds percent makes the resulting ice unsuitable for the preparation of ice mixtures transported by water pumps, which are widely, along with flake ice, currently used for refrigeration in the food industry, agribusiness and fishing. The aim of the present invention is to develop a device for producing ice with a given particle size and reduce energy costs for their production.

This goal is achieved by the fact that the ice chipping tool, a cylindrical cutter, is made with spiral cutting edges consisting of knives of different shapes discretely spirally arranged, the width of the base of the knives and the gaps between them being equal, and the knives themselves located on spirals in such a way that each knife of the previous edge is located opposite the gap between the knives of the subsequent edge. To ensure symmetry, the number of cutting edges must be even.

Figure 1 schematically shows a device for producing ice in the form of a cutter, figure 2 shows a top view of the cutter; figure 3 - scan surface of the cutter; figure 4 shows the main characteristic dimensions of the cutter knives; figure 5 - the shape and size of the faces of the knives of the cutter.

On the cylindrical base of the mill 1 is an even number of spiral-shaped cutting edges of the knives 2 (Fig.1, 2). The cutting edges of the knives 2 are discretely located along the spirals of the knives (Fig. 3), spaced apart by a distance S (Fig. 4) equal to the width of the base of the knife S ₁ and the distance S ₂ between the cutting edges. To increase the pressure from the cutting edge of the cutter to the surface of the ice being chipped off from the ice-forming surface, the angle a of the knife faces (Fig. 5) located perpendicular to the tangent to the spiral of the cutting edge can vary from 90 ° to arctg 2h / S, where h is the height of the knife, S is the width of the base of the knife.

The device operates as follows. The knives due to orbital rotation around the cylindrical surface of the drum-evaporator of the ice generator exert increased local pressure on the ice located on its surface. The pressure from the side of the discretely arranged knives is the higher, the greater is the ratio of the contact areas of the discrete knife and the integral cutting edge at their contact with the surface of the ice being chipped. Since the efforts on the cutter when working with discrete knives are lower compared to a cutter with a continuous cutting edge, the energy costs for chipping ice are reduced. The sizes of ice particles when using this device directly correlate with the S parameter and, as a rule, do not exceed the maximum size between the points where the knife touches the ice surface. At the same time, the height of the knives h should be 0.1 greater than the maximum thickness of the obtained ice.

Table 1 shows the experimental data obtained by comparing the proposed and known devices. A cylindrical milling cutter with a continuous cutting edge and cylindrical milling cutters were compared, on the edges of which knives were formed with discrete rectangular and trapezoidal shapes with a base width of each knife equal to S = 10 mm and angles of 90 ° and 60 ° with a knife height h = 7.7 mm. Ice particles were calibrated using a sieve.

Table 1 No. δ, mm Type of work milling cutter Relative specific energy consumption, W / kg The number of failures per kg of ice The amplitude of the beats mm. Average ice particle size mm one Continuous Cutter one one ~ 1 up to 60 mm 2 3 Discrete rectangular knife cutter 0.86 - - 9 × 10 3 Discrete trapezoidal knife 0.75 - - 12 × 18 one Continuous Cutter one four 1-2 up to 45 mm 2 5 Discrete rectangular knife cutter 0.8 - > 0.5 10 × 10 3 Discrete trapezoidal knife 0.7 - - 14 × 19 one Continuous Cutter one 7 2-3 up to 40 mm 2 7 Discrete rectangular knife cutter 0.78 one ~ 1 12 × 16 3 Discrete trapezoidal knife 0.66 - > 0.5 14 × 19 + 10% ice slush δ is the thickness of the chipped ice

As can be seen from the table, the specific energy consumption of a mill with discrete rectangular and trapezoidal shapes is reduced compared to a mill with a continuous cutting edge. With an ice thickness of 3 mm by 14-25%, with an ice thickness of 5 mm, respectively, 20-30%, with an ice thickness of 7 mm, respectively, 22-44%, with a minimum variation in particle sizes, that is, with practically the same particle sizes. At the same time, when using a mill with a continuous cutting edge, a significant dispersion of the particle sizes of the resulting ice from the ice slurry to ice sizes of 40-60 mm is obtained. In this case, the particle sizes reliably correlate with the characteristic size S. Under the condition that the blades are 0.1 mm thicker than the ice thickness, changing the characteristic size S, you can vary the sizes of the resulting particles over a wide range, limited only by the technical and technological capabilities of manufacturing the device.

Literature

1. Bobkov V.A. Production and use of ice. M .: Food industry, 1997, 231 p.

2. Marenyuk B.T. and other Environmentally friendly methods of obtaining water ice. The magazine "Refrigeration business", No. 2, 2008

3. Bal VV, Verein EP Technology of fish products and technological equipment. Agropromizdat. 1990 g.

4. Kolodyaznaya B.C., Sokolov V.N. The choice of the optimal product-coolant ratio when freezing food in ice suspensions. Collection of Low-temperature and food technologies in the XXI century. SPb. T.2, 2003 - 396 s.

5. Fomin N.V., Menin B.M., Rzhevskaya V.B., Guiko E.M. Drum freezers. L .: Engineering, 1986

Claims (2)

1. Device for producing ice, containing on a cylindrical surface spiral-shaped continuous cutting edges, characterized in that the even number of spiral-shaped edges of the device consist of discretely arranged knives of various shapes along them, while the width of the base of each knife, the distance between them and between the cutting edges are equal and the knives themselves are located on the spirals of the cutting edges in such a way that each knife of the cutting edge is located opposite the gap between the knives of the subsequent and previous edges. 2. The device for producing ice according to claim 1, characterized in that the angles of the planes of the knives located perpendicular to the tangent at the point of their location on the spiral edge, vary from 90 ° to arctg 2h / S, where h is the height of the knife, a S - the width of the base of the knife.

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