RU2244231C1 - Drier with fluidized layer - Google Patents

Abstract

FIELD: food and chemical industries.

SUBSTANCE: invention can be used in dispersed material driers with active hydrodynamic layer (with fluidization). Proposed drier contains drying chamber with grid bottom and drying agent inlet branch pipe. Drying chamber accommodates striker with reciprocating drive passing through layer of material to be dried at starting of drier. In period of starting, when velocity of drying agent is below critical compact layer of particles of material to be dried is broken in one place by shocks of striker applied during 1-3 s at 0.5-6 Hz and penetrating through layer. Integrity of layer is thus destructed, and dispersed product changes into fluidized state. Reduction of fluidization velocity and pressure differential on drying chamber bottom improved efficiency without loss of quality.

EFFECT: provision of drier of simple design.

1 dwg

Description

The invention relates to the field of food and chemical industries and can be used in dryers with an active hydrodynamic layer (with a fluidized bed, aero-fountain, etc.).

A known fluidized bed dryer [1, 2], in which dispersed material is loaded onto a grate under the drying chamber and blown from the bottom up by the drying agent.

The disadvantage of this method is the need for increased pressure drops on the lattice and the layer of the dried material.

Closest to the claimed invention is a device [3] comprising a drying chamber with a perforated hearth, nozzles for introducing a drying agent and a dried material, nozzles for introducing a drying agent in a tangential direction and nozzles for withdrawing a dried material and spent drying agent.

The disadvantage of the prototype is the low efficiency caused by the increased entry speed of the drying agent and the pressure drop across the hearth.

The problem to which the invention is directed, is to increase efficiency by reducing the differential pressure on the hearth of the drying chamber and the speed of input of the drying agent into it.

This is achieved by the fact that in a device containing a drying chamber with a trellised hearth and a nozzle for introducing a drying agent, a striker with a reciprocating drive is installed in the drying chamber, which moves through the layer of the dried material during the launch of the dryer. The invention is illustrated in the drawing.

The device consists of: a drying chamber 1 with a perforated hearth 2 and a nozzle for introducing a drying agent 3, a hammer 4 with a drive 5 and a drive mount for the hammer 6 in the drying chamber.

The device operates as follows. When starting the dryer, the speed of the drying agent in the drying chamber 1 gradually increases. At a time when its speed has not yet reached a critical value (the rate of fluidization onset), but an air cushion has already formed between the perforated hearth 2 and the dispersed material, the drive of the striker 5 is turned on for 1 ... 3 seconds, and the striker 4 delivers one or more strikes with with a frequency of 0.5 ... 6 Hz over a layer of dispersed material, punching it through (to the air cushion). This leads to the destruction of the integrity of the layer of dispersed material on the lattice, which, in turn, leads to the implementation of the fluidization regime. As a result, the fluidization regime is realized at a drying agent speed less than critical. As a result, the pressure drop across the bottom of the drying chamber and the speed of the drying agent in the fluidization mode are reduced; accordingly, energy costs for supplying a drying agent are also reduced. The drive force of the striker does not exceed 1 ... 3 Newtons.

A drying chamber with a striker and its mechanical or electric drive are easier to perform than, for example, a drying chamber with tangential air flow. The decrease in the rate of fluidization and differential pressure on the bottom of the drying chamber ensures the economic efficiency of the proposed dryer without loss of drying quality.

Sources of information

1. Ginzburg A.S., Rezchikov V.A. Fluidized bed food drying. - Moscow, Food Industry, 1966. - 196 p. (p. 104-114).

2. Pat. No. 2182298 Russia, IPC ⁷ F 26 V 17/10, Dryer of the gushing layer / S.T. Antipov, S.V. Shakhov, Yu.V. Ryakhovsky, A.V. Pribytkov; Voronezh. state technol. Acad. - No. 2001100441/06; Claim 01/05/2001; Publ. 05/10/2002, Bull. 13.

3. Pat. No. 2178242 Russia, IPC ⁷ F 26 V 17/00, Dryer of the flowing layer for dispersed materials / S.T. Antipov, A.V. Pribytkov; E.A. Shirshov; Voronezh. state technol. Acad. - No. 2001106758/09; Claim 03/12/2001; Publ. 01/10/2002, Bull. 1. - (Prototype).

Claims (1)

A fluidized bed dryer containing a drying chamber with a perforated hearth and a nozzle for introducing a drying agent, characterized in that a striker with a reciprocating drive is installed in the drying chamber, which moves through the layer of the dried material during the launch of the dryer.