SU1002794A1 - Heat exchange apparatus for heat treating of loose materials - Google Patents

Description

The invention relates to heat exchange devices designed for the heat treatment of bulk materials.

A heat exchanger for cooling and securing granular materials is known, which comprises a vertical body, inside of which there are one horizontal horizontal shelves with holes disposed one relative to another. The shelves are attached to the inner wall of the housing of the apparatus by one side with the formation between the wall and the other side of the channel for the flow of material to the underlying shelf. Under each shelf are located air distributors into which air is blown by the fan for cooling, which then passes through the holes in the shelf and a layer of material. Regulating elements are hinged at the ends of each of the shelves, which provide for the accumulation of a certain amount of material on the shelf and removal of cooled granules G IT.

This unit works inefficiently because it requires a large air flow due to its single interaction with the material.

1 In addition, this apparatus is distinguished by the complexity of the device and the high meteoric capacity. The regulating elements cannot pass large inclusions; therefore, the grids are easily clogged with and the apparatus inefficiently cools the granular bulk material.

10 A heat exchanger for heat treatment of bulk materials is known, which contains a shaft and heat exchange sections arranged alternately on opposite walls with a given step along its height and completed in the form of (J-shaped tubes fitted with transverse plate ribs and fixed on the wall of the shaft with using detachable tubing pipes 20.

The disadvantage of this device lies in its low efficiency, namely: materials with large inclusions clog the gaps between the fins of the heat exchanger, as a result of which the hydraulic resistance increases, the redistribution of air inside the shaft is disturbed, as a result of which most air goes outside the fins, and therefore plowing

30 the efficiency of fluidization of the material, and hence the efficiency of its cooling. This device is also characterized by low efficiency of using the heat exchange surface, since in order to eliminate material loss in the apparatus it is necessary to maintain low air circulation speeds, which means that the height of the fluidized bed of material in this case should be small, therefore, it should contact the edges very low height, which means that high-height ribs are not economical, which limits the size of the heat exchange surface. As a result, pain is necessary to cool the material. s water consumption. Large particles of material in the apparatus come into contact with small particles during the entire cooling process, and since they cool much slower than small particles, they therefore give off heat to them in contact with small particles, reducing the efficiency of the cooling process as a whole. The purpose of the invention is to improve the operational reliability and economy of the heat exchanger. The goal is achieved by the fact that in a heat exchanger for heat treatment of bulk materials, there is a shaft and heat exchange sections, arranged alternating on opposite walls with a predetermined pitch along its height and made in the form of u-shaped tubes, provided with transverse plate ribs and fixed on the shaft wall with the help of removable tube sheets, the ribs in each section in the sections protruding beyond the limits of the U-shaped tubes are made of different sizes, decreasing in the direction from the tube grid, and the guides are provided Additional elements with the same inclination as the main ones, but directed towards the tube sheet, are attached to the middle part of the ribs placed between the pipes, with the device additionally containing a cooler connected to the shaft from the intersectional space side. FIG. 1 shows schematically the proposed heat exchanger; FIG. 2 - one of the heat exchange sections of the proposed heat exchanger / FIG. 3 - the same plan view. The heat exchanger contains a shaft 1, heat exchange sections 2, made in the form of u-shaped pipes 3, equipped with plate fins 4 and fixed to the wall of the shaft by means of removable tube sheets 5, guide elements 6, additional guide elements 7, cooler 8, with nozzles 9 installed inside and inclined shelves 10 attached to a feeder I. The mine is equipped with a nozzle 12 for supplying hot bulk material & la, a nozzle 13 for supplying cooling air, a nozzle 14 for discharging dust, a nozzle 15 for withdrawing particles of bulk material feeder 16 for discharging the cooled particles of the bulk material. The device works as follows. Hot material through the pipe 12 enters the inclined elements of the ribs 4 in the upper part of the shaft. Large particles are removed along oblique elements 6 without failure and by inertia enter the cooler 3, where they are irrigated with water by the nozzles 9 and, passing through the inclined shelves 10, are cooled, discharged from the cooler 8 by the feeder 11. Fine particles (bases; to a cooled material fraction it is evenly distributed in the gaps between the ribs 4 and enters the downstream section in the same way. From the last ribbed section the material enters the feeder 16 and is discharged from the shaft 1. Air for cooling is supplied from the atmosphere through pipe 13 to the bottom part of the shaft is sucked through it by a high-pressure fan installed after the dust collectors (not shown in Fig. 1). The material moving along the guide elements 6 of the sections 2 is intensively blown with an upward air flow. The cold water circulating through the U-shaped pipes 3, sections 2, cool the surface of the fins 4 with inclined elements b, 7; the latter intensively receive heat from the hot material moving along them. The heated air enters the dust collectors (not shown) and is emitted into the atmosphere. In the proposed heat exchanger, clogging of large particles of the fins is eliminated, as the inclined elements in the upper part of the fins are offset in height and length relative to each other, set at an angle that ensures material flow form a supporting grid, a failure for small particles (the main fraction of the cooled material) and unprotected for large ones (6e 50-6 O mm. Since large particles have a larger than small particles, and energy is higher. Therefore, the transition from one ramp to the other inertial they pass a greater distance than small ones. The inclined elements .ney top portions of the ribs are offset along the length of

over a distance smaller than the flight length of particles of size 6–50–60 mm, which excludes the failure of large particles in the gap between the inclined sections. Large particles run down the inclined elements and by inertia enter the cooler where they are irrigated through the nozzles and sloping shelves are cooled. Small particles (Y5 50-60 mm), the flight length of which by inertia during transfer from one inclined element to another is shorter than the distance between the plates, fall down and move in the space between the edges along the middle and lower inclined sections, and fall on Following heat exchanger section.

In order to evenly distribute the cooled material (small particles |. In the spaces between the ribs, the distances along the length between the inclined elements in the upper part of the fins of the heat exchange section are unevenly distributed, but in all positions they are smaller than the flight length of particles 3–50–60 mm. The minimum size is set between the first and second inclined elements, since at this point the largest; 0 is the volume of material. And the size of the place of the last and the last but one inclined elements is maximum, but not longer than the inertial flight. particles from 50–60 mm. This virtually eliminates the slippage of small particles into the cooler, designed to cool large particles of d350-60 mm. –P The size between the last inclined element and the side wall of the vertical shaft is smaller than the inertial flight length of particles of size BE 50-60 mm All these dimensions for each particular material are determined experimentally. The length distance between the inclined elements in the upper part of the fins for the heat exchange sections located below is permanent, since the inclined elements in the lower part of the edges of the sections provide uniform distribution of the material on the lower sections. These distances are also determined experimentally. The distance between the last inclined element in the upper part of the ribs and the side wall of the vertical shaft is 1.5-2.0 times the average particle size of the cooled material, but not less than 10-15 mm.

The displacement of the inclined elements in the upper part of the ribs in height H makes it possible to adjust the living section for the passage of cooling air. This allows an increase in the air flow without increasing the dust loss, therefore, it is possible to reduce the water consumption for cooling and remove more heat by air.

Thus, the proposed apparatus has the following advantages over the known ones: no compressed air consumption for additional product transfer, no power consumption for compressed air supply for pumping; reduction of metal and energy intensity of the apparatus; no loss of product with discharges into the atmosphere; the absence of rotating parts and the destruction of the basement as a result of the drive vibration.

Claims (2)

1. Heat exchanger for heat treatment of bulk materials, containing a shaft and heat exchange sections arranged alternately on opposite walls with a zig zachanny step along its height and made in the form of (J-shaped tubes equipped with transverse plate ribs and fixed on the wall of the mine using removable tube grids which, in order to increase operational reliability and cost-effectiveness, in each section in the sections, protruding beyond the limits of the U-shaped pipes, they are made of different sizes, decreasing in the direction from the tube sheet, and are provided with guide elements arranged with a given inclination, while additional directions are attached to the middle part of the ribs located between the pipes elements with the same slope as the main elements, directed towards the tube sheet. 2. The apparatus according to claim 1, characterized in that it further comprises a coolant, which is adjacent to the mine from the intersectional space side. And the costs for formations, taken into account in the examination 1. French patent fJ 2055215, cl. F 28 d 15/00, 1971. 2. USSR Copyright Certificate No. 2870608, CL R 25 D 1/00 1980. ffO / nfffVff / r F1 / g.