RU2442085C2 - Method for drying flax stalks - Google Patents

Abstract

FIELD: flax drying.

SUBSTANCE: method for drying flax stalks includes the preparation of flax stalk layer and its transportation with the simultaneous hot air blow-off in the form of a flow limited in its width. According to the method the flow is directed to the central part of the layer along the width of the moving stalks. The width is changing and it depends on the average length of the stalks and the square deviation of the stalk ends in root and in top parts of the layer.

EFFECT: cost reduction.

1 dwg

Description

The invention relates to the field of drying, and in particular to methods of drying stem bast-fiber materials, for example linen flax trusts.

Currently, the flax fiber production technology used in domestic flax plants requires drying of the stems of the flax stane trust before mechanical processing. The applied drying methods and equipment for their implementation were created in conditions of low cost of energy resources and sufficient financial support from the state in terms of covering depreciation deductions for equipment. In market conditions, the use of existing equipment has become economically unprofitable, which has led to the refusal of a number of enterprises to dry trusts. The consequence of this was a decrease in the yield of long fiber and a deterioration in its quality. Therefore, the use of more economical drying methods is currently required.

A known method of drying bast-fiber materials, which involves drying trusts in a stream [1]. However, the use of this method does not ensure the rational use of the coolant. This method also requires the use of large and energy-intensive drying machines.

There is also a method of drying flax seeds using a special device [2]. This method includes preparing a layer of stalks of flax seeds, its transportation with simultaneous blowing with heated air in the form of a stream limited in width.

The disadvantage of this method is the irrational use of the coolant due to the poor distribution of its flows during drying of the stems. The fact is that the median sections require the greatest degree of drying, since with subsequent scuffing, it is they that, in the worst degree, become aggravated. The end sections of the stems during scrubbing are subjected to the greatest tensile stresses and therefore should be dried less. This is due to a decrease in the breaking strength of the fiber with a decrease in its moisture content. Thus, differentiation is required according to the degree of drying of different zones of the stems along their length.

In addition, the disadvantage of this method is also the irrational conditions for the supply of coolant in a changing layer width (due to the variation of the length of the stems along the length of the tape) and the extension of the stems, leading to uneven distribution on the surface of the mesh conveyor.

Due to the variation in the width of the layer of stems along the edges or along one of the edges, there will be free space from the layer on the conveyor. This will lead to the fact that the direction of the coolant during its movement will shift from the center of the layer. As a result, the drying efficiency of the middle sections of the stems, which, according to the technology of mechanical processing, require an increased intensity of impacts from the working bodies of the machines, will decrease.

As a result of these shortcomings, when implementing the known method of drying flax trusts, increased energy costs are required, which results in increased dimensions of the drying device, providing drying of the middle sections of the stems to the required process humidity.

The mentioned method of drying flax trusts in its technical essence and the achieved effect is closest to the claimed one and therefore it can be chosen as a prototype.

An object of the invention is to increase the drying efficiency and reduce energy costs for its implementation due to a more rational use of the coolant based on the properties of the processed linen trusts.

The solution of this technical problem is achieved by the fact that in the method of drying flax trusts, which includes preparing a layer of stalks of flax trusts, transporting it with simultaneous blowing with heated air in the form of a stream limited in width, according to the invention, a stream of heated air is directed into the middle zone along the width of the moving layer of stems, the value of which can vary and depends on the average length of the stems and the mean square deviations of their ends in the butt and apical parts of the layer.

The direction of the heated air flow into the middle zone along the width of the moving stalk layer, the value of which is regulated and depends on the average length of the stems and the mean square deviations of their ends in the butt and apical parts of the layer, will provide the following technological effects.

Firstly, the direction of the heated air flow into the middle zone along the width of the layer, the size of which depends on the average length of the stems and the mean square deviations of their ends in the butt and apical parts of the layer, will ensure that there are no transporter sections in this zone . This is due to the fact that the distribution of butt and apical sections of the stems obeys the normal law, according to which the layer will have a zone completely filled with stems, that is, there will be no sections free of stems on the conveyor.

Secondly, it follows from the theory of the mechanical treatment of flax stalks [3] that, when the trusts of fibers are separated from the stalks by fibers, the most intensive mechanical processing occurs in relation to the terminal sections of the stems. The middle part is processed worse. Therefore, in practice, for a better study of the middle sections of the stems, an increase in the intensity of the scrubbing process is always required. However, this leads to trimming of the terminal sections of the stems and fibers, that is, to unjustified fibrous losses.

Along with this, the dependence of the separability of the fiber from the bonfire, as well as the breaking strength of the fiber on the moisture content of the original stems, is known. The drier the stems, the better the bonfire is separated from the fiber in them, but there is a decrease in the tensile strength of the fiber. Therefore, from these patterns follows the feasibility of better drying of the middle sections of the stems. For the terminal sections of such drying, there is no need to produce, based on the condition of conservation (not reduction) of the breaking strength of the fiber. Thus, by drying the middle part of the stems, the decortication ability of their middle sections will improve, and the breaking strength of the fiber in the end sections will be preserved (not reduced) without improving their ability to de-sharpen (since there are no problems with decontamination of the end sections of the stems). This, ultimately, will lead to a better de-sharpening of the median sections of the stems and the conservation of fibrous complexes in their end sections when scrubbing.

Thirdly, the regulation of the size of the zone along its width, depending on the average length of the stems and the mean square deviations of their ends in the butt and apical parts of the layer, will ensure the drying efficiency of stems with different properties and structure. For example, when drying short-stalked raw materials, the size of the zone should be reduced. The reduction of the zone is also required when drying the layer of stems with increased extension of the stems or increased unevenness along their length.

From the explanations presented, it follows that the direction of the flow of heated air into the middle zone of the moving layer of stems in width will increase the drying efficiency due to a more rational use of the coolant (warm air) based on the properties of the processed linen trust.

The invention is illustrated in the drawing.

The drawing shows a flow chart of the proposed method of drying. The layer of stems of trusts 1, formed as a result of unwinding the roll, moves along the distributing duct 2 by means of a ring conveyor 3. Hot air (coolant) is supplied to the layer of stems and enters the middle zone of the width of the layer A, the value of which can be approximately determined by the formula

L _cp -3 (σ _to -σ _c ),

where L _cp is the average length of the stems in the layer; σ _to , σ _to, respectively, the standard deviations of the butt and apical ends of the stems of the linen trust. Next, the coolant, passing through a layer of stems, leaves the drying zone. If necessary, it can be enriched with air from outside the drying zone and reused for re-drying the trusts.

Upon receipt of the processing of the next roll from it form a layer of stems. The parameters are evaluated in this layer: L _cp — average length of stems in the layer; σ _to , σ _in, respectively, the mean square deviations of the butt and apical ends of the stems. After that, determine the width of the zone A, in which the coolant will be supplied using the formula

L _cp -3 (σ _to -σ _c ).

Next, changing the width of the duct, set this value to A and dry the stalks of the linen trust.

Using the proposed method will require lower costs for its implementation in comparison with the currently existing in practice methods and devices for drying linen trusts.

Information sources

1. Drying and moistening of bast-fiber materials: a textbook for high schools. - M.: Light Industry, 1980.

2. USSR author's certificate No. 1523866, authors: E. N. Tokmakov, A. A. Potarin, A. N. Pigalov. Publ. 11/23/89, bull. No. 43.

3. A.M. Ipatov. Theoretical foundations of the machining of stalks of bast crops: a textbook for universities. - M .: Legprombytizdat, 1989.

Claims (1)

A method of drying flax trusts, including preparing a layer of stalks of flax trusts, transporting it with simultaneous blowing with heated air in the form of a stream limited in width, characterized in that the stream of heated air is directed into the middle zone along the width of the moving layer of stems, the value of which varies and depends on the average stalk lengths and root mean square deviations of their ends in the butt and apical parts of the layer.