SU1764765A1 - Installation for cooling friable materials - Google Patents

Abstract

Use: in foundry to increase cooling efficiency. SUMMARY OF THE INVENTION: In the device, corrugations of sheets forming, together with the plates, cavities for the bulk material and channels for the coolant are horizontally oriented, the surface of each corrugated sheet is positioned relative to the plates with a gap, forming successively narrowed and widened sections in a vertical direction. The rate of movement of the cooled material along the cavities is controlled by varying the degree of alignment of the outlet openings in the bottom plate of the cooling chamber and in the gate, with a corresponding displacement of the gate, in order to achieve the required temperature of the bulk material leaving the cooling chamber. 2 hp ff, 3 it

Description

The invention relates to a foundry and can be used to cool bulk materials used to form castings.

A cooler of loose materials, mainly molding sands and waste mixtures, is known, which contains a loading hopper, under which a cooling chamber with horizontally installed pipes connected to a coolant supply-and-discharge system, and a discharge gate hopper are installed. Vertical ribs are mounted on the pipes; a grid with a cell size equal to 0.1-0.8 distances between adjacent vertical ribs is installed between the hopper and cooler.

Known cooler has low efficiency, because The bottom of each pipe and the coolest adjacent rib areas are shadow and do not participate in heat exchange.

The closest technical solution to the invention is a device for cooling molding sand, which contains a hopper with an inclined screen, a cooling chamber communicated by collectors to the refrigerant line, and a discharge bin with a feed gate. Its cooling chamber is divided by vertical partitions to form airtight cavities for sand and coolant channels. The upper and lower walls of the chamber are made in the form of perforated plates, a drive gate with a time relay is installed under the lower plate. The partitions of the chamber are made in the form of plates and sheets with corrugations installed vertically with the formation of cavities and channels of a triangular cross section.

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In this device, in the cavities the sand moves vertically only during the filling and emptying of the cavities of the cooling chamber, and the cross-section mixing of the sand does not occur at all. The main cooling of bulk materials occurs when it is stationary due to heat transfer from the boundary layers of the material to its middle part. Because the heat transfer coefficient of bulk materials, such as sand, is low, so its cooling rate is low. In this device, the bulk material is cooled with the discharge gate closed. The water in the channels of constant cross section is moving in a laminar mode with a thicker boundary layer that worsens the conditions of heat transfer from the walls of the cooling channels. The cooling efficiency of materials with this device is low.

The aim of the invention is to increase the cooling efficiency of bulk materials.

This goal is achieved by the fact that in a device for cooling bulk materials containing a hopper with an inclined grid, a cooling chamber, in which the top and bottom walls are made in the form of perforated plates, and the cavities for the bulk material and channels for cooling fluid are formed by vertical partitions in the form plates and corrugated sheets, as well as a gate under the lower perforated plate and a discharge hopper with a feeder, the coolant channels being connected through the collectors to the coolant line According to the invention, the corrugations of the sheets are horizontally oriented, the surface of each corrugated sheet is placed relative to the plates with a gap, with alternating narrowed and widened sections in the vertical direction, the holes in the lower perforated plate of the cooling chamber are smaller in cross section than the smallest cross-section of the cavity for bulk material. Moreover, the gate is made with holes, the size and placement of which corresponds to the size and placement of the holes in the lower perforated plate of the cooling chamber, and the dimensions of the bridges between the holes in the gate are larger than the dimensions of the corresponding holes. Alternatively, the plates of the cooling chamber are also corrugated and their corrugations are mirrored with respect to the corrugations of the sheets.

Figure 1 shows a diagram of an apparatus for cooling bulk materials, a general view; Fig. 2 shows an embodiment of the cooling chamber of the device; in FIG. 3, node I in FIG.

A device for cooling bulk materials contains a hopper 1, in the lower part of which an inclined grid 2 is installed, equipped with a vibrator. Under

0 by the hopper 1 a cooling chamber is mounted, the upper and lower walls of which are made in the form of perforated plates 3 and 4, respectively. The sheets 5 of the cooling chamber are made with horizontally directed corrugations and are mounted between flat vertical plates 6 (FIG. 1) with a gap between the protrusions of the corrugations of the sheets 5 and the plates 6 with the formation of cavities 7 for sand and channels 8 for

0 coolant. The cavities 7 and the channels 8 in the direction of movement of the cooled material and the cooling fluid are made with successive alternating narrowed portions - constrictions 9 and

5 extended sections - diffuser extensions 10. It is advisable to carry out the corrugations in such a way that the length of the contractions is several times smaller than the length of the extensions, their alternation in cavities 7

0 goes from top to bottom, and in channels 8 - from bottom to top. Sheets 5 and plates 6 are perpendicular to their plane with vertical ribs (not shown).

Alternatively, the formation of cavities 7 and

5 channels 8 with constrictions 9 and extensions 1C are achieved by fabricating plates 6 with corrugations and mounting them mirrored with respect to corrugations of sheets 5 (Fig. 2).

Passing section of cavities 7 in suzh

0 or x 9, no more than the total cross-section of the openings in the plate 3 occurring in the cavity and connecting the cavity 7 with the loading hopper 1 are made. These holes in the plate 3 are made in the form

5 fine perforation. Sealed strips ™ 7 are drilled with holes 11 with bushings sealed into them in the bottom plate 4 connected to a discharge bin 12 and a feeder 13. Between plate 4,

0 by the hopper 12 is mounted with the possibility of reciprocating the movement of shi ber 14 with holes 15, the size and placement of which corresponds to the dimensions and placement of the holes 11 in the slab 4 chamber

5 cooling. The dimensions of the bridges between the adjacent holes 15 in the gate 14 are not less than the corresponding dimensions of the indicated holes. The gate 14 has a drive (n; not shown). When the slide 14 is displaced, the effective area from

Versions 11 in plate 4 change from maximum (if the holes in the plate 4 and gate 14 coincide) to zero (if the holes in the plate 4 coincide with jumpers between the holes 15 in gate 14). The flow area of the holes 11 in the plate 4 for each of the cavities 7 is smaller than the flow area of the constriction 9 of the corresponding cavity.

The channels 8 are connected to the system for supplying and discharging coolant (water) through the manifolds 16 and 17, cavities 18 and holes 19 in the plates 4 and 3. The hopper 1 is loaded through the loading port 20.

The device works as follows.

Before starting, the gate 14 is advanced. Its jumpers overlap the openings 11 of the plate 4 of the cooling chamber (Fig. 3).

The cooled bulk material through the hatch 20 enters the loading hopper 1 and through the inclined grid 2 with a vibrator and the upper finely perforated plate 3 — into the cavity 7 of the cooling chamber, filling them all the way up. At the same time, coolant (water) is supplied to the manifold 16, which fills the cavity 18 in the plate 4 and through the holes 19 it feels into the channels 8. When moving through the constrictions 9, its speed increases. When moving along diffuse extensions 10, the flow of water becomes turbulent, which sharply intensifies the mixing of water in the channels 8 and the flow of cooler water to the channel walls. This breaks down the boundary near-wall layer of water, which facilitates the access of colder water to the walls of the channel. Passing through all restrictions 9 and expansions 10 of channel 8, the heated water collects in the cavity 18 of plate 3 and is discharged from the device through the collector 17. Due to the movement of water in channels 8 in a turbulent mode, the cooling of the sheets 5 and plates 6 as well as attached to them ribs.

The gate 14 is slid into the cooling chamber body, aligning its holes 15 with the holes 11 in the plate 4, thus adjusting the speed of movement of the bulk material along the cavities 7 to ensure its cooling to the optimum temperature, approximately 40 ° C during material movement cooling chamber.

When the bulk material moves along the cavity 7, the cavities remain filled all the time, since the bore sections of the holes 11 in the plate 4, coming in at one narrowing 9 in the cavity 7, are smaller than the cross section of this narrowing, which is less than the total bore of the corresponding holes in the plate 3. The material that has passed through the constriction 9 is replaced by a material from diffuser expansions in each cavity 7, both from the middle part of the extensions 10 and from the cavity walls. The material from the layers above fills the resulting voids, including near the walls. Another hotter material flows to the walls. By mixing the hotter material with the already cooled one, the walls come in contact with the hotter material and its more efficient cooling.

Improving heat transfer conditions from

bulk material to the wall of the cavities 7 and the conditions of heat extraction from the walls by cooling water increases the cooling efficiency of the bulk material.

Claims (3)

1. A device for cooling bulk materials, comprising a hopper with an inclined grid, a cooling chamber, in which the top and bottom walls made in the form of perforated plates, and the cavity for the bulk material and coolant channels are formed by vertical partitions in the form of plates and corrugated sheets, as well as a gate under the lower perforated plate and the discharge hopper with a feeder, the coolant channels communicating through the collectors to the cooling line fluids different By the fact that, in order to increase the cooling efficiency, the corrugations of the sheets are made horizontally directed, the surface of each corrugated sheet is placed relative to the plates with a gap, with alternating narrowed and widened sections in the vertical direction, the holes in the lower perforated plate of the cooling chamber are smaller. than the smallest flow area of the cavities for the bulk material. 2. Pop-1 device, characterized in that the gate is made with holes, the size and placement of which correspond to the size and placement of holes in the lower perforated plate of the cooling chamber, and the size of the bridges between the holes in the gate are larger than the dimensions of the corresponding holes. 3. The device is pop.1, characterized in that the plates of the cooling chamber are also made corrugated and their corrugations are mirrored with respect to the corrugations of the sheets.  Fi. four & (/ g, Editor M.Egorova Fig.Z Compiled by V. Kalentiev Tehred M.MorgentalKorrektor P.Geershi Fig.Z