SU1366823A1 - Drier for raw cotton - Google Patents

Abstract

Invention m. used in cotton plants and their procurement centers. The purpose of the invention is to intensify the drying process and increase productivity. For this, the lower cavity is provided with a nozzle 13 connected to the suction system. Seals 11 and 12 are set at an angle from the horizontal in the direction of rotation of the drum 1. The inlet pipe of the suction heat carrier (TH) from the vertical is also set at an angle in the direction of rotation of the drum 1. The dryer provides additional processing of raw cotton in the filter layer in synchronous mode movement in the section pr motoka. The location of the TH inlet pipe ensures the purging of a layer of cotton. The flow rate of the aspirated pipe 13 ТН is selected taking into account the maximum speed of the layer blowing. 4 il. F (L

Description

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The invention relates to a technique for drying raw cotton and can be applied in cotton factories and their processing centers.

The aim of the invention is to intensify the drying process and increase productivity.

Fig. 1) shows the dryer, the general VID5 of Fig.2 is a section A-A of Fig.1; on fig.Z - section BB in figure 1; Fig. 4 shows curves of changes in the parameters of the drying process over time.

The raw cotton dryer contains a rotating drum 1 placed in chamber 2 with an exhaust pipe 3, a loading shaft 4 and an unloading mechanism 5. The drum 1 has a slope to the horizon in the direction of the unloading mechanism 5 and is divided in length into three sections. At the beginning of the drum 1, a section 6 of the straight section is placed, then a perforated section 7 for cleaning the raw material and discharging the spent heat carrier, conjugated with the exhaust pipe 3 and then section 8 of the countercurrent. Section

6 has a fixed end wall 9 connected to the loading shaft 4 and the i O pipe for supplying high-temperature heat transfer fluid (Fig. 2) In the joint between section 7 of drum 1 and chimney 3 there are seals 11 and 12 (in the form of shields) , and under section 7 there is a pipe 13 for suctioning a part of the high-temperature heat-transfer agent from the drum 1 and the separated litter. Seals 11 and 12 are attached to the pipe 3 and are adjacent to the drum generators, which are at an angle of about 50-55 ° to the horizon in the direction of rotation. At the same angle and in the same direction, offset from the vertical axis of the drum 1 and the nozzle 10 of the high-temperature heat transfer fluid ( 2).

The dryer works in the following way.

Wet raw cotton is fed into the rotating drum 1 by the charging charge 4, where it is moved in the direction of the unloading mechanism 5 due to its inclined position. At the length of section 6, the material is processed in the flow by the high-temperature moist heat carrier supplied to the drum 1 through the pipeline 10, and then after section 7 over section 8, with a dry heat transfer medium supplied by the countercurrent. Dried raw cotton is unloaded by the unloading mechanism 5 and is fed for further processing. Raw cotton when passing through section 6 is pulsed by blowing at a heat carrier speed - 0.2-0.10 m / s with a frequency of 2-0.3 Hz . In this case, at maximum speed, the coolant is supplied during only one third of each period. During the remainder of the period, the rate of blowing cotton cotton is maintained at 0.2 m / s.

In contrast to the known in the proposed dryer, when passing through section 7, a layer of raw cotton formed on the perforated surface and located within the sector enclosed by the diffuser of nozzle 13 (on the length of the perimeter between the seals (shields 11 and 12) is blown by the transverse flow This is achieved by placing the pipe 10, seals 11 and 12 at an angle of 50-55 ° and having a suction pipe 13. After passing through the suction section (zone of the pipe 13) chl (- raw raw Under the action of the weight, the drum is first lowered to the center, then slides from the center to the periphery and lies on the drum side around the drum 12 to form a layer. As a result, the raw cotton is stirred intensively outside the heat suction portion of the pipe 13. Next, the layer of raw cotton is again blown transverse flow of heat carrier. The processes of blowing the layer and mixing cotton are repeated on each turn of the drum.

Thus, in the dryer, additional processing of cotton in the filter bed is provided in a mode synchronous to the movement of the high-temperature heat transfer fluid in the section of the motorcycle, with the duration of the layer processing impulse equal to half of each period. Location taken

nozzle 10 provides within ,. the duration of the impulse of processing is purging the layer of raw cotton at maximum speed and for only one third of the period. At the same time, the flow rate of the aspirated pipe 13 of the heat transfer medium is selected taking into account the achievement of the maximum speed of blowing a layer of raw cotton, namely 0.4-0.7 m / s.

31366823

processing of raw cotton in the field

A part of the flow of heat-transfer fluid used in section 6 is used in the friction layer. In this section, when the heat transfer fluid having high temperature and humidity comes into contact with cold raw cotton, there is an intensive heat and mass transfer between them. forced heating of cotton and, most importantly, seeds, in which the main share of moisture is concentrated.

As a result, the raw cotton entering section 7 of the drum contains dried outside segments with partially dried seeds inside. At the same time, the fibrous cover of seeds has increased moisture. This makes it relatively easy to remove moisture from the environment around the seeds by blowing a layer of raw cotton with a relatively dry heat carrier. Processing in the filter layer also provides partial. drying the fibrous cover and supplying directly to the seeds of heat necessary to support the process of moisture transfer.

In section 8, cotton is supplied partially dried and in a state that ensures further dispersion of moisture throughout the material and accelerated mass transfer upon contact with the coolant.

The pulsating purge of the layer and the alternation of the purge with mixing of raw cotton also contributes to an increase in processing efficiency and an increase in the quality of drying. Stirring eliminates overheating of individual sections of cotton and allows the heat carrier used in section 6 to be blown off. Section 6. The high-temperature moist heat carrier, section 6 passing, gives the cotton syr part of heat and moisture and enters section 7 having parameters suitable for processing raw cotton in the filter bed.

The choice in the proposed dryer for the duration of the impulse to process the layer equal to half the cycle period and the time for purging the layer with a maximum speed equal to one third of the period is made according to empirical dependencies and is justified by the results of experimental studies.

For example, it has been established experimentally that a further increase in the first is associated with a sharp increase in the aerodynamic resistance of the dryer, and an increase in the second one of the third

a period (although it accelerates drying) leads to yellowing of the fiber, which is unacceptable. A decrease in the first and second leads to a decrease in the effect achieved.

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Claims (1)

Invention Formula Dryer for raw cotton containing rotary rotary in the chamber a drum with a system of partitions, forming successive sections of the motorcycle, cleaning and countercurrent sections, the first of which is adjacent to the fixed end wall with and the second section is separated by seals adjacent to the drum-forming seals on the upper and lower cavities, respectively, connected to the exhaust pipe and the unloader of litter, which, in order to intensify the drying process and increase productivity, the lower cavity equipped with a pipe connected to the suction system, and the seals are set at an angle of 50-55 ° to the horizontal in the direction of rotation of the drum, and the pipe of the input of high-temperature The deflector to the vertical is also set at an angle of 50-55 in. side of rotation of the drum. A: A // /// /// // 7/ /// /// /// /// /// Rig. 2 Fig t