RU44804U1 - BOILER LAYER DRYER FOR THERMOLABLE POLYDISPERSIVE BULK MATERIALS - Google Patents

Abstract

The utility model relates to the technique of drying thermolabile bulk materials in an oscillating mode and can be used in chemical, processing, food and other industries and agriculture. The proposed dryer is simple in design and allows to achieve high quality drying in a fluidized state of polydisperse fine-grained materials. The dryer is characterized in that the partitions dividing the superlayer volume into two sections, located behind the bulk windows, are equipped with a bulk material selector, and the central generatrix of the annular chambers is made in the form of a truncated cone.

Description

The utility model relates to devices for drying thermolabile bulk materials using a directionally moving fluidized bed in an oscillating mode and can be used in chemical, food and other industries.

A known fluidized bed dryer [1], comprising a vertical casing, separated by gas distribution without gratings, supporting a layer of material on half-ring annular chambers with a central cylindrical generatrix, communicating with each other by filling windows in the gratings and having a radial partition in each of them, the lower and the upper chamber are connected respectively to the gas inlet and gas outlet boxes, in each chamber a second partition is installed that separates together with the first the superlayer volume is divided into two sections by a partition, the gas supply and gas outlet boxes are also divided by vertical partitions into two compartments, corresponding to the sections of the chambers for autonomous supply to and discharge of different-temperature gas from them.

The disadvantage of the dryer is a decrease in the drying efficiency due to the formation of stagnant zones, uneven gas distribution and removal of individual particles from the fluidized bed zone, the short residence time of particles in each section and the bulkiness of the dryer.

The utility model is aimed at increasing the drying efficiency of polydisperse materials by eliminating stagnant zones and entrainment of fine-grained material, increasing the compactness of the dryer.

This is achieved by the fact that the partitions dividing the superlayer volume into two sections are located behind the bulk windows and are equipped with a bulk material selector, the central generatrix of the annular chambers is made in the form of a truncated cone.

Figure 1 schematically shows the proposed dryer, a longitudinal section; figure 2 is a side view; figure 3 is a section aa in figure 1.

The dryer contains a cylindrical vertical housing 1, a gas-free gas distribution grill 2, annular chambers 3, restrictive partitions 4, additional partitions 5 with windows 6, sections 7 and 8 of the annular chambers 3, overflow windows 10 with estrus 11, a gas supply 12 and a gas outlet 13, separated on compartments 14-17 by partitions 18 and 19, loading 20 and unloading 21 pipes, the central generatrix of the upper annular chamber in the form of a cone 22, the material selector in the form of a rotary valve 23.

The dryer operates as follows.

Hot air is supplied to the "hot" compartment 14 of the gas supply duct 12, and cold air to the "cold" compartment 15. Dried

the material continuously flows through the loading pipe 20 into section 8 of the upper annular chamber 3, which also receives hot air from the lower sections 7. Under the influence of oblique jets of air coming from the gas distribution grid 2, the material is fluidized and moves along the ring through the window 6, through section 8 , to the overfill window 10. In section 8, the material is treated with cold air. Then the material enters through the poured window 10 and estrus 11 into the underlying annular chambers 3, in which a similar oscillating treatment with hot and cold air is carried out. The annular chambers 3 are made expanding in height due to the presence of a central generatrix 22 in the form of a cone. The speed of the fluidizing agents after exiting the fluidized bed decreases to a value that is lower than the speed of the particles of the processed material, which allows drying of particles of various sizes, eliminating the entrainment of particles from the annular chambers and clogging of gas distribution grids located above them. At the end of section 8, a part of the material is delayed by the rotary damper 23 and through the sector overflow window 10 and then through the estrus 11 it enters the chamber located below. The rest of the materials again goes to the drying section 7. The frequency of circulation of the material within each section depends on the specific type and polydispersity of the dried material, as well as its size and humidity.

The dried material is discharged through the discharge pipe 21, and the corresponding coolant is discharged through the respective compartments 16 and 17 of the exhaust duct 13.

The proposed dryer is simple in design and allows to achieve high quality drying with intensive process control.

A source:

1. A.S. USSR No. 1276888. Publ. 12/15/86. Bull. №46

Claims (1)

Fluidized bed dryer for thermolabile bulk materials, comprising a vertical casing separated by gas distribution gridless grids supporting a layer of material on belt-shaped annular chambers with a central cylindrical generatrix communicating with each other through bulk windows in the gratings and having a partition in each of them, the lower and upper the chambers are connected respectively to the gas inlet and gas outlet boxes, in each chamber there is a second partition separating a place with a first partition, the superlayer volume into two sections, the gas supply and gas outlet boxes are also divided by vertical partitions into two compartments, corresponding to the sections of the chambers for autonomous supply of different temperature gases to the latter and removal of them, characterized in that the partitions separating the superlayer volume into two sections located behind the bulk windows, equipped with a sampler of bulk material, and the Central generatrix of the annular chambers is made in the form of a truncated cone.