RU2490575C2 - Drying plant for solutions, suspensions and paste-type materials - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: drying plant for solutions, suspensions and paste-type materials consists of a housing with a spraying chamber arranged in its upper part and equipped with an injector and a header for supply of heat carrier, a drying chamber with a vibro grain mill located in the central part of the chamber, and a heat carrier gas distribution system. Drying plant also includes solution supply and spent heat carrier cleaning system. Gas distribution system is equipped with two gas-distributing units: top and bottom. Top unit supplies heat carrier to spraying jet root and is designed for uniform distribution of heat carrier along the sprayed material jet. Bottom gas distributing unit allows for supplying heat carrier to the lower part of the housing, where a gas-distributing grate is installed. The grate is provided with nozzles to supply secondary heat carrier and a chute for granules discharge. Vibro grain mill is installed in central part of the housing in the form of a vibrating tray with a screen bottom with perforation coefficient equal to 0.3…0.5, and a perforated plate elastically fixed at the bottom by means of springs with perforation coefficient equal to 0.5…0.7, and a vibratory drive has a control unit, by means of which direction, amplitude and frequency of vibration is changed in the required optimum range of operating parameters of the granulating plant: vibration level is in the range of 100…120 dB, frequency of an oscillating process is in the range of 50…100 Hz; each injector consists of a cylindrical part with outer thread for connection to a nozzle of distributing pipeline and two in-series connected hollow cylindrical-conical belts coaxial to it, and coaxial to the housing, in its lower part there fixed is a nozzle formed with outer conical surface and an end blind partition wall perpendicular to the nozzle axis, in which there is a central throttle hole and at least three inclined holes at an angle of 45° to the nozzle axis; on the nozzle conical surface there is a cylindrical collar with outer thread for connection of the nozzle to lower cylindrical-conical belt of the housing; on the nozzle, on the side opposite to liquid supply, there is an additional row of jet nozzles which are formed at least with three pairs of mutually perpendicular vertical channels for liquid passage and horizontal channels which are intersected on a conical side surface of the nozzle and form outlet holes of each jet nozzle; paired channels are located at a right angle to each other in longitudinal planes of the housing; conical side surface of the nozzle has the apex angle equal to 90°, and two rows of throttle holes are made on the cylindrical-conical belt rigidly attached o the cylindrical part of the housing: one row represents at least three horizontal holes made on cylindrical surface; the other row represents at least three inclined holes at an angle of 45°, which are made on conical surface; in horizontal plane the projections of axes of holes in those rows are located at the distance from each other through an angle lying in optimum range of values of 7.5…60°. On the cylindrical-conical belt connected to the nozzle by means of inner thread there is a row consisting of at least three horizontal throttle holes; in horizontal plane the projections of axes of holes and jet nozzles, which are formed at least with three pairs of mutually perpendicular vertical and horizontal channels on conical side surface of the nozzle, are located from each other through an angle lying in optimum range of values: 7.5…60°.

EFFECT: improvement of drying efficiency.

3 dwg

Description

The invention relates to techniques for drying dispersed materials and can be used in microbiological, food, chemical and other industries.

The closest technical solution to the claimed object is a dryer according to the patent of the Russian Federation No. 2335715, F26B 17/10, containing a drying chamber, a gas distribution system of a drying agent, a solution supply system and an exhaust air purification system (prototype).

The disadvantage of the prototype is the relatively low productivity of drying the final product.

The technical result is an increase in drying performance.

This is achieved by the fact that in the installation for drying solutions, suspensions and pasty materials, comprising a housing with a spray chamber located in its upper part, equipped with a nozzle and a collector for supplying a coolant, a drying chamber with a vibrating granulator located in the central part, and a gas distribution system for the coolant, a solution supply system and a waste heat carrier cleaning system, a gas distribution system is equipped with two gas distributors: an upper and a lower one, while the upper gas distribution the distributor brings the coolant to the root of the spray torch and is designed to evenly distribute the coolant along the spray of the sprayed material, and the lower gas distributor allows the coolant to be introduced into the lower part of the housing, where a gas distribution grill with nozzles for supplying the secondary coolant and estrus for the exit of granules is installed, and in the central part of the housing a vibration granulator is located in the form of a vibrating tray with a mesh bottom with a perforation coefficient equal to 0.3 ... 0.5, and elastically fixed and the bottom by means of springs of a perforated plate with a perforation coefficient equal to 0.5 ... 0.7, and the vibrodrive has a control unit with which to change the direction, amplitude and frequency of vibration in the required optimal range of granulator operation parameters: vibration level in the range - 100 ... 120 dB, the frequency of the oscillatory process in the range of 50 ... 100 Hz.

Figure 1 shows a diagram of an installation for drying solutions, suspensions and pasty materials, figure 2 is a variant of a vibratory granulator, figure 3 is a nozzle for spraying liquids.

Installation for drying solutions, suspensions and pasty materials (figure 1) contains a housing 1 with a spray chamber 2 located in its upper part, a nozzle 3 and a collector 4 for supplying coolant 16 from above. The dried material is fed to a vibration granulator, made in the form of spring-loaded top and bottom springs 13, a vibrating tray 5 with a mesh bottom 6 and a ball nozzle 7 driven into vibration by the vibration drive 11. The housing 1 at the location of the vibration drive is made detachable with spring-loaded springs 12 parts. Under the weight of the ball nozzle, the material is forced through the mesh bottom, and under the influence of the vibration of the tray and the gravity of the particles themselves, the latter are torn off, of the same size. Then the particles fall into the lower part of the housing, where a gas distribution grid 8 with a pipe 9 for supplying a secondary coolant is installed. Here, the material is dried in the fluidized bed mode and in the form of granules of the same size is released through estrus 10.

Figure 2 presents an embodiment of a vibratory granulator in the form of a vibrating tray 5 with a mesh bottom 6 with a perforation coefficient equal to 0.3 ... 0.5, and elastically fixed to the bottom 6 by means of springs 14 of a perforated plate 17 with a perforation coefficient equal to 0, 5 ... 0.7. The vibrodrive 11 has a control unit (not shown in the drawing), which changes the direction, amplitude and frequency of vibration in the required optimal range of granulator operation parameters: vibration level in the range - 100 ... 120 dB, oscillation process frequency in the range - 50 ... 100 Hz and the perforated plate 17 performs the functions of the inertial mass of the dynamic vibration damper tuned to the desired frequency range. The spring-loaded perforated plate 17 oscillates in the vertical plane and transmits the vibration energy for mixing and forcing through the mesh bottom 6. Exhaust dusty gases are subjected to preliminary acoustic treatment in acoustic installation 18, the optimal parameters of which for sound processing of medium-fine dust are: sound pressure level 140 dB or more, the frequency of the vibrational motion of 900 Hz, the concentration of dust in the air stream at least 2 g / m ^3, while the audio 1,5 ... 2 , After which the gas stream is directed into the cyclone hopper 19, where is allocated the bulk of the dry material entrained gases, and the final purification of gases occurs in the bag filter 20.

The nozzle (figure 3) contains a hollow body, consisting of a cylindrical part 21 with an external thread for connecting to the nozzle of the distribution pipe for supplying fluid, and two hollow cylindrical-conical belts 22 and 23.

Coaxial to the body, in its lower part, a nozzle 24 is formed, formed by the outer conical surface and the end, perpendicular to the axis of the nozzle, a blind partition 25, in which a central throttle hole 26 and at least three inclined holes 27 are made at an angle of 45 ° to the axis nozzles. On the conical surface of the nozzle 24, a cylindrical flange with an external thread is made for connecting the nozzle to the lower cylinder-conical belt 23 of the housing.

The housing and the nozzle 24 form among themselves several coaxial inner cylindrical chambers 28, 30, 31, 32 and a conical chamber 29.

The chamber 28 serves to supply fluid, the chambers 29, 30, and 32 are expansion chambers, and the chamber 31 performs the functions of a pressure chamber of increased pressure.

On the nozzle 24, from the side opposite the fluid supply, an additional row of nozzles is made, which are formed by at least three pairs of mutually perpendicular vertical channels 36 for the passage of liquid and horizontal channels 35 that intersect on the conical lateral surface of the nozzle 24 and form the outlet openings each of the jets. Paired channels 35 and 36 are located at right angles to each other in the longitudinal planes of the housing. The conical lateral surface 24 of the nozzle is made with an angle at the apex equal to 90 °.

On the cylinder-conical belt 22, rigidly connected to the cylindrical part 21 of the body with an external thread, two rows of throttle holes are made: one row is at least three horizontal holes 33 made on a cylindrical surface, the other row is at least , three inclined holes 37 at an angle of 45 °, made on a conical surface. Moreover, in the horizontal plane of the projection of the axes of the holes 33 and 37 in these rows are separated from each other by an angle of 7.5 ... 60 °.

On the cylinder-conical belt 23 connected to the nozzle 24 by means of an internal thread, a row is made consisting of at least three horizontal throttle holes 34. Moreover, in the horizontal plane of the projection of the axes of the holes 34 and the nozzles, which are formed by at least three pairs mutually perpendicular vertical 36 and horizontal 35 channels on the conical lateral surface of the nozzle 24, are separated from each other by an angle lying in the optimal range of values: 7.5 ... 60 °.

The gas distribution system is equipped with two gas distributors: an upper and a lower one, while the upper gas distributor brings the drying agent to the root of the spray plume and is designed to evenly distribute the coolant along the spray of the sprayed material, and the lower gas distributor allows the coolant to be introduced into the lower part of the housing where the gas distribution grill with nozzles for supply of secondary coolant and estrus for the exit of the granules.

Installation for drying solutions, suspensions and pasty materials works as follows.

A high evaporation rate of moisture is achieved in the dryer due to fine atomization of the dried material in the drying chamber through which the drying agent (heated air or flue gases) moves. When spray-dried, the specific evaporation surface becomes so large that the drying process is completed extremely quickly (in about 15 ... 30 s).

In the spray dryer, the material is fed into the chamber 2 through the nozzle 3. The drying agent moves in parallel current with the material through the collector 4. The dried material enters the vibration granulator, made in the form of spring loaded top and bottom springs 13, a vibrating tray 5 with a mesh bottom 6 and a ball nozzle 7 driven by vibrator 11. Housing 1 at the location of the vibrator is made detachable with spring-loaded springs 12 parts. Under the weight of the ball nozzle, the material is forced through the mesh bottom, and under the influence of the vibration of the tray and the gravity of the particles themselves, the latter are torn off, of the same size. Then the particles fall into the lower part of the housing, where a gas distribution grid 8 with a pipe 9 for supplying a secondary coolant is installed. Here, the material is dried in the fluidized bed mode and in the form of granules of the same size is released through estrus 10.

Small solid particles of dried material (up to several microns in size) are discharged through a collector located between the spray chamber 2 and the housing 1 and enter the output collector, and from there, first to the acoustic unit, where the acoustic agglomeration of small particles takes place, and then to the cyclone and bag filter (not shown in the drawing). Spent drying agent after cleaning from dust in the cyclone and bag filter is released into the atmosphere.

The nozzle works as follows. When the fluid is supplied to the housing 21 under the action of a pressure drop of 0.4 ... 0.8 MPa, capillary turbulent fluid flows are formed in the channels and throttle openings, rushing to the outlet sections of these openings.

After the collision of the fluid flows in the channels 35 and 36, and the outflow through the nozzle outlet openings, a fan-shaped gas-liquid flow is formed in the form of a shroud, i.e. a liquid droplet crushing mechanism is implemented, but the generated swell-like flow deviates from the horizontal plane by a larger angle, in the range from 45 to 60 °, in the direction of the central region of the irrigated surface located directly under the central throttle hole 26 in the blind partition 25 of the atomizer. This distribution of the sprayed liquid allows to increase the uniformity of the spraying of the liquid over the Central part of the irrigated surface.

The voltage of evaporated moisture for this dryer is 2.5 ... 3 times greater than for dryers with conventional gas distribution. Spray dryers also work according to the principles of counterflow and mixed current. However, direct flow is especially common, as it allows drying at high temperatures without overheating of the material, and the rate of deposition of particles in this case is the sum of their speed and the speed of the drying agent. This type of spray dryer is used to dry solutions, suspensions and pasty materials.

Claims (1)

Installation for drying solutions, suspensions and pasty materials, comprising a housing with a spray chamber located in its upper part, equipped with a nozzle and a collector for supplying a coolant, a drying chamber with a vibrating granulator located in the central part, a gas distribution system for a coolant, a solution supply system and a waste cleaning system coolant, the gas distribution system is equipped with two gas distributors: upper and lower, while the upper gas distributor supplies heat carrier to the root of the spray torch and is designed to evenly distribute the coolant along the spray of the sprayed material, and the lower gas distributor allows you to enter the coolant into the lower part of the housing, where a gas distribution grill with nozzles for supplying the secondary coolant and estrus for the exit of granules is installed, and in the central part of the housing there is a vibration granulator in the form of a vibrating tray with a mesh bottom with a perforation coefficient equal to 0.3 ... 0.5, and elastically fixed to the bottom by means of springs perforated plate with a perforation coefficient equal to 0.5 ... 0.7, and the vibrodrive has a control unit with which to change the direction, amplitude and frequency of vibration in the required optimal range of granulator operation parameters: vibration level in the range of 100 ... 120 dB, vibrational frequency process in the range of 50 ... 100 Hz, characterized in that each of the nozzles consists of a cylindrical part with an external thread for connecting to the nozzle of the distribution pipe and two serially connected and coaxial hollow cylinders of the conical belts, and a nozzle formed coaxially with the casing in its lower part is formed by the outer conical surface and the end perpendicular to the nozzle axis with a blank partition, in which the central throttle hole and at least three inclined holes are made at an angle of 45 ° to the nozzle axis the conical surface of the nozzle is made of a cylindrical flange with an external thread for connecting the nozzle to the lower cylindrical conical belt of the housing, while on the nozzle from the side opposite to the fluid supply, made a series of nozzles, which are formed by at least three pairs of mutually perpendicular vertical channels for the passage of liquid and horizontal channels that intersect on the conical lateral surface of the nozzle and form the outlet openings of each of the nozzles, and the paired channels are located at right angles to each other the longitudinal planes of the housing, while the conical lateral surface of the nozzle is made with an angle at the apex equal to 90 °, and on the cylinder-conical belt, rigidly connected to the cylindrical part of the core a mustache, two rows of throttle holes are made: one row is at least three horizontal holes made on a cylindrical surface, the other row is at least three inclined holes at an angle of 45 ° made on a conical surface, while in the horizontal plane of the projection of the axes of the holes in these rows are separated from each other by an angle lying in the optimal range of 7.5 ... 60 °, moreover, on the cylindrical conical belt connected to the nozzle by means of an internal thread, a row is made , consisting of at least three horizontal throttle openings, while in the horizontal plane of the projection of the axes of the holes and nozzles, which are formed by at least three pairs of mutually perpendicular vertical and horizontal channels on the conical side surface of the nozzle, are separated from each other by an angle lying in the optimal range of magnitudes of 7.5 ... 60 °.

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