RU2367865C1 - Cylinder drier with channel nozzle - Google Patents

Abstract

FIELD: heating, drying.

SUBSTANCE: invention concerns drying equipment, particularly bulk material processing method for rotating cylinder with channel nozzles, and can be applied for bulk material drying in chemical, food and other industries. Cylinder drier with channel nozzle includes rotating cylinder with lengthwise channels, immobile material feed and air supply devices, and immobile discharging chamber. Novelty of invention is comprised by additional immobile spent air outlet device in cylinder drier structure. The device is made in the form of chamber adjoining lengthwise channel ends and fixated rigidly at the inlet end of cylinder; air feed device in the form of chamber adjoining channel ends and fixated rigidly in discharge chamber. All channels feature solid transverse partition, additional air supply channel is positioned inside cylinder, and transverse channel partitions can be implemented to perform longitudinal travel and include stops.

EFFECT: reduced specific heat cost for drying, enhanced performance.

4 cl, 2 dwg

Description

The invention relates to a drying technique, in particular to a technique for processing bulk materials in a rotating drum with channel nozzles, and can be used for drying bulk materials in the chemical, food and other industries.

Known designs of drum dryers [and.with. No. 1366824 F26В 11/04, BI No. 2, 1988], in which the drying agent moves along the channels along the generatrix of the shell, leaves the channels through slots, passes through a layer of granular product above the layer and leaves the drum. The degree of filling of such drums is 15 ... 25% of the volume of the drum.

A disadvantage of the known drums is that when the degree of filling of the drum increases, the bulk product enters the channels for the drying agent, as a result of which the drying is stopped, and also that the speed of the drying agent in the different channels is not the same, since the sectional shape of the layer is a segment, thickness which is not constant.

Known dryer for bulk materials [and.with. No. 227916 F26В 19/01, BI No. 30, 1968], containing a rotatable drum, on the inner surface of which there are longitudinal perforated pipes with a hollow cylindrical nozzle placed along its axis, as well as inlet and outlet pipes connected to the drum from the ends for the heat carrier.

The disadvantage is that the coolant passes a different path from the channel of its supply to the layer to the open surface from which it is removed, which leads to its uneven speed and does not allow to use its potential most effectively.

Known drum dryer [patent No. 2153135 F26 11/04, publ. 2000.07.20], in which the drum is divided by a vertical longitudinal partition into lifting and lowering parts. In the lowering part, gas supply and gas collectors are fixedly mounted along the entire length of the drum.

The disadvantage of this device is: low specific moisture removal (kg / s m ³ drum volume), since the purge and, accordingly, the drying of the material occur only in part of the drum volume; high specific energy consumption, due to the fact that the amount of heat for heating the air is overestimated relative to the minimum required (due to increased air consumption due to insufficient moisture saturation during short-term contact of each volume with material), as well as high aerodynamic resistance of the air path of the dryers due to the installation of two collectors with consecutive openings.

The closest in technical essence and the achieved effect to the proposed is a drying drum [US Pat. No. 1838735 A3, cl. F26V 25/16 publ. 08/30/93, bull. No. 32], in which air is supplied under a dense layer of moving material through longitudinal channels located on the inner surface of the drum. Air is supplied only to the channels located under the layer of material through a device placed on the fixed wall of the rotating drum.

A disadvantage of the known drying drum is the increased heat consumption for drying due to the relatively high air consumption due to its incomplete moisture saturation during passage through the material layer, as well as the supply of air with the same temperature to all drying zones along the length of the drum, which leads to an increase in energy consumption and causes low productivity of a drying drum.

An object of the invention is to reduce the specific heat consumption for drying, as well as increasing the productivity of the installation when drying heat-sensitive materials.

The technical task of the invention is achieved in that in a drum dryer with a channel nozzle, including a drum with longitudinal channels, mounted for rotation, fixed devices for loading material and air supply, as well as a fixed discharge chamber, it is new that the drum dryer is additionally equipped with a fixed device for exhaust air, which is a chamber adjacent to the ends of the longitudinal channels and motionlessly located at the boot end of the drum, air supply, which is a chamber adjacent to the ends of the channels and fixedly located in the discharge chamber, all channels are equipped with a continuous transverse partition, and inside the drum there is a channel for supplying additional air, while the transverse partitions of the channels can be made with the possibility of their longitudinal movement and equipped with clamps, and the channel for supplying additional air along its entire length may have openings for air outlet equipped with control devices in the form of valves NOC, and the length may be divided by partitions into continuous sections, each of which is connected to a separate device for heating the air.

The technical result is to reduce the specific heat consumption for drying, as well as to increase the productivity of the installation when drying heat-sensitive materials.

Figure 1 presents a longitudinal section of a drum dryer, and figure 2 is a cross section along aa

A drum dryer with a channel nozzle (FIGS. 1, 2) includes a drum 1 with profile nozzles 2 forming longitudinal channels 3, inside of which there are continuous transverse partitions 4, which can be made with the possibility of their longitudinal movement and provided with clamps (not shown). The drum 1 is mounted rotatably with the help of bandages 5 and 6, a support 7 and a drive roller 8.

The drum dryer with a channel nozzle is equipped with a fixed device for loading material 9, passing through a fixed end wall 10 with a device for exhaust air 11 mounted on it, which is a chamber adjacent to the ends of the longitudinal channels 3.

The air supply device 12, which is a chamber adjacent to the ends of the channels 3, is stationary in the discharge chamber 13, which includes the open end of the drum.

Inside the drum 1, there is a channel 14 for supplying additional air, which along its entire length can be equipped with openings for air outlet and control devices in the form of dampers (not shown), and can also be divided along the length by solid partitions into sections, each of which is connected to a separate device for heating the air.

The product layer 15 in the drum 1 is located on the surface of the profile nozzles 2.

A drum dryer with a channel nozzle operates as follows. The dried material through a stationary loading device 9 enters the drum 1 and is placed in a layer 15 on the surface of the profile nozzles 2, running along the entire drum 1. When the drive roller 8 is rotated (its drive is not shown conditionally), the drum 1 rotates, the bandages 5 and 6 of which interact with drive 8 and supporting 7 rollers. Under the action of rotation of the drum 1, the material is mixed, moving from the end wall 10 to the discharge end of the drum, and then poured into the discharge chamber 13, from which it is removed outside the dryer. At the same time, the coolant in the form of heated air is supplied to the channels 3. In this case, when the drum 1 is rotated, the longitudinal channels 3 are adjacent to the stationary devices for supplying 12 and air exhaust 11, arranged in such a way (Fig. 2) that the air supply and exhaust occurs only through the channels under the material layer 15.

Air heated to a temperature T ₁ (devices for heating and air supply are not shown conventionally) enters the inlet part of the channels 3 and through longitudinal slotted openings between the profile nozzles 2 along their length enters under the layer of material 15 and under the action of a feeding device (for example, a fan ) passes through the layer of material 15, dries it and leaves the layer 15 through its upper surface with a temperature T ₂ . This movement of air occurs in sections of the channels 3 (Fig. 1) between the supply device 12 and the transverse partition 4 (the supply part of the channels). Through the duct 14, additional air with a temperature of T ₃ enters the free upper part of the drum 1, forming a mixture with a temperature of T ₄ with air with a temperature of T ₂ . This mixture, under the action of the difference in air pressure in the space above the layer 15 and in the outlet part of the channels 3, located under the layer of material 15 between the transverse partitions 4 and the exhaust air device 11, passes through the layer of material 15 in the front part of the drum 1 along its course. In this case, the material loses moisture, and the air is additionally saturated with it, its temperature drops to T ₅ .

Thus, in the first along the material part of the drum 1, the material is dried at a higher air velocity and lower temperature than in the second part. This drying mode corresponds to the general laws and mechanism of moisture removal (O. Krischer. Scientific principles of drying technology. Publishing House of Foreign Literature, M., 1961. - 539 p.), Providing more intensive moisture removal at lower cost of heat than drying with constant temperature and air speed.

Obtaining the result is ensured by the following. The air supplied under the layer of material 15 passes through it, saturated with moisture, mixes with additional air and re-passes through the layer of material. The increase in the contact path of the material-air ensures its higher saturation with moisture and, accordingly, reduces the need for air and heat consumption for its heating. For thermolabile materials (for example, grain crops), the maximum temperature of the supplied air is limited by the requirements for the quality of the dry material, and usually, the higher its humidity, the lower the permissible temperature. Therefore, the temperature of the supplied air in the prototype is the minimum allowable, which leads to a slowdown in drying and, thereby, to a decrease in the productivity of dryers. In the proposed installation, air is supplied under a layer of material dried in the previous (along the material) part of the drum. Accordingly, its temperature may be higher than in the prototype, which will speed up the drying and increase the productivity of the installation, as well as reduce the specific energy consumption (it is known that with increasing temperature the specific heat consumption for drying decreases).

The advantage of the proposed drum dryer with a channel nozzle over the known one is that its use allows to reduce the specific heat consumption for drying, as well as to increase the productivity of the installation when drying heat-sensitive materials due to:

- adaptation of the installation to the requirements of the ongoing process by creating instead of one two drying zones in it, ensuring a greater compliance of the drying regime with the requirements of the optimal process;

- increase the temperature and reduce the flow of air supplied to the dryer;

- more complete use of the drying potential of the air due to the lengthening of its path through the material and, accordingly, the increase in the time of their contact.

Claims (4)

1. A drum dryer with a channel nozzle, including a drum with longitudinal channels, mounted for rotation, fixed devices for loading material and air supply, as well as a fixed discharge chamber, characterized in that it is additionally equipped with a fixed device for exhaust air, which is a chamber adjacent to the ends of the longitudinal channels and motionlessly located at the boot end of the drum, the air supply device, which is a chamber adjacent to the ends channels and motionlessly placed in the discharge chamber, all channels are equipped with a continuous transverse partition, and inside the drum there is a channel for supplying additional air. 2. The device according to claim 1, characterized in that the transverse partitions of the channels are made with the possibility of their longitudinal movement and are equipped with clamps. 3. The device according to claim 1, characterized in that the channel for supplying additional air along the length has openings for air outlet, equipped with control devices in the form of dampers. 4. The device according to claim 1, characterized in that the channel for supplying additional air along the length is divided by solid partitions into sections, each of which is connected to a separate device for heating the air.

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