CN115608258A

CN115608258A - Sludge granulation method and device in caffeine production

Info

Publication number: CN115608258A
Application number: CN202211363511.0A
Authority: CN
Inventors: 韩峰; 周英壮; 郭少卿; 张腾; 李小宋; 张剑
Original assignee: Shijiazhuang Pharmaceutical Group New Norwich Pharmaceutical Co ltd
Current assignee: Shijiazhuang Pharmaceutical Group New Norwich Pharmaceutical Co ltd
Priority date: 2022-11-02
Filing date: 2022-11-02
Publication date: 2023-01-17
Also published as: CN116173831A; CN116173831B

Abstract

A sludge granulating method for caffeine production includes such steps as taking cyanoacetic acid and dimethyl urea as raw materials, taking acetic anhydride as dewatering agent, reacting to obtain caffeine, dewatering, granulating sludge, extruding in screw extruder to obtain sludge strips, cutting into blocks, and granulating. The spiral slideway is arranged, so that the rolling shaping process of sludge particles is prolonged, the sludge particles are more smooth and firm in appearance, the heating drying time is long, and the stable shaping and good appearance of the sludge particles are ensured. The invention has the advantages that all the procedures are continuous production, the finished sludge particles are uniform and consistent, the sludge granulation efficiency is improved, and the subsequent treatment and application are convenient.

Description

Sludge granulation method and device in caffeine production

Technical Field

The invention relates to the technical field of environmental protection, in particular to a method and a device for treating discharged sludge in caffeine production.

Background

Caffeine (1,3,7-trimethylxanthine) is a xanthine alkaloid, a central nervous system stimulant and a beverage additive. The caffeine is mainly prepared by chemical synthesis, cyanoacetic acid and dimethyl urea are used as raw materials, acetic anhydride is used as a dehydrating agent, condensation reaction is carried out to generate dimethyl cyanoacetylurea, cyclization reaction is carried out under the condition of liquid alkali to generate dimethyl-4 AU, then dimethyl-NAU → dimethyl-DAU → dimethyl-FAU are sequentially generated, liquid alkali is added into the dimethyl-FAU to synthesize theophylline sodium salt, solid theophylline sodium salt is obtained by centrifugation, and then the caffeine is formed by methylation reaction. The crude caffeine is dissolved in water, oxidized and decolored, crystallized, centrifuged, dried, crushed and the like to obtain the fine caffeine.

The waste water and sludge produced in the production of caffeine are more, the pollutant components in the waste water are complex, and the waste water and sludge comprise intermediate products of chemical reaction, caffeine semi-finished products, caffeine finished products and the like, and substances which are required to be added for removing certain components in the waste water. Such as activated carbon, lime extractants, kerosene, etc., and these components and reaction products also remain in the wastewater and precipitate to form sludge. A medium-output factory needs thousands of tons of wastewater to be treated every day, and a sewage tank and a sludge tank with large volumes need to be built.

The pollutant components can be roughly divided into two categories of organic and inorganic, wherein the organic pollutants comprise organic cyanides, chlorine, carboxylic acids, amines, ureas, esters, purines and other nitrogen-containing organic matters; the inorganic contaminants are mainly sodium ions, ammonium ions, iron ions, chloride ions, sulfate ions, nitrate ions, nitrite ions, and inorganic cyanide ions, and the like, and sodium ions, chloride ions, and sulfate ions are abundant.

The waste discharged from caffeine production has the characteristics of high organic matter concentration, complex components and poor biodegradability. The organic pollutants contained in the wastewater are complex in structure, difficult to degrade, extremely low in BOD/COD of the wastewater, poor in biochemical property and difficult to treat by a common biochemical method. The color of the caffeine wastewater is reddish brown, and the wastewater is acidic due to the existence of organic acid, purine and other substances, has a pH value of 4-5, is high in toxicity, and is mostly strong-corrosive, highly toxic and volatile chemicals such as cyanogen compounds, heterocyclic compounds and the like. In addition, nitrogen is an important element in the composition of caffeine, and thus the discharged wastewater contains a large amount of nitrogen, particularly kjeldahl nitrogen. Since such sludge discharged from caffeine production contains a large amount of organic substances, nitrogen, phosphorus, potassium and trace elements, as well as various harmful chemical substances, bacteria, microorganisms, heavy metals, etc., these sludge can be used as either inoculated activated sludge or as fillers, fillers or building materials, but for any purpose, they are generally subjected to preliminary harmless treatment and are prepared into granules for convenient transportation or use.

The common sludge granulation is completed in a granulation roller, blocky sludge with proper size is put into the granulation roller, and the blocky sludge rolls continuously in the roller through the rotation of the roller, so that the blocky sludge can be rolled into a ball shape. However, the roller granulation device can only carry out intermittent production, once charging and once forming, and after the granulation is finished and the discharging is finished, new materials need to be charged again to carry out the granulation, so that the continuous production cannot be realized.

The Chinese patent discloses an equipment for manufacturing particles with the application number of CN 201520532317.X, which is named as 'equipment for manufacturing particles', and provides equipment for manufacturing mud-like substances such as sludge and the like in a bouncing mode. The method utilizes elastic steel wires and other materials such as spokes to quickly, massively and moderately poke mud-like materials such as sludge into required particles, and the size of the particles is adjustable. A plurality of spokes in the device form a radial rotatable circular structure, and the outer contour of the circular structure is matched with the outlet of the muddy material preparation device; when the catapult rotates, the outer edge of each spoke sequentially contacts the flat plate at the outlet of the mud-shaped material preparation device, and the width of each spoke is matched with the diameter of mud-shaped material particles such as sludge to be prepared. The patent has a peculiar concept, but the prepared particles have irregular shapes and low appearance, and cannot meet the requirements of related fields.

Therefore, it is also generally desirable to provide a better method for producing particles from sludge and a manufacturing apparatus thereof.

Disclosure of Invention

The invention aims to provide a sludge granulation method and a device thereof in caffeine production, wherein the sludge can be prepared into granules by continuously rotating or rolling the sludge which is used as a raw material, so as to solve the problem that the sludge is inconvenient to store, transport and use.

In order to solve the technical problem, the invention adopts the following technical scheme:

a sludge granulation method in caffeine production is characterized in that cyanoacetic acid and dimethyl urea are used as raw materials, acetic anhydride is used as a dehydrating agent to carry out a series of reactions to prepare caffeine, sludge discharged in caffeine production is dehydrated and then enters a sludge granulation process and is sent into a spiral conveying extruder, a sieve plate is arranged at the lower part of the right end of the spiral conveying extruder, extruded sludge is prepared into sludge strips through the sieve plate, the sludge strips are cut into blocks by a cutting mechanism and fall into the sludge granulation mechanism, the sludge granulation mechanism is a rotary outer barrel and an inner barrel, an inner barrel with a slightly smaller diameter is sleeved in the outer barrel, the upper part of the inner barrel is a material receiving convex hump, the material receiving convex hump is in a spherical segment shape with a slightly pointed top, the bottom surface of the material receiving convex hump is connected with a spiral slideway, the spiral slideway is spirally configured along the outer wall of the inner barrel, and after the spiral slideway rotates for a plurality of circles, the lower part of the material receiving convex hump gradually bends to enter the center of the inner barrel and extend out of the bottom of the inner barrel; the blocky sludge falling into the sludge granulation mechanism falls to the bottom from the material receiving bulge and then rolls along the spiral slideway, and rolls into granules all the way and falls into a finished product box; the lower end parts of the outer cylinder and the inner cylinder are rotatably supported on the annular rotating mechanism; the outer cylinder and the inner cylinder are provided with rotary driving parts, each rotary driving part comprises an annular big gear and a small gear, and the small gear drives the annular big gear to further drive the outer cylinder and the inner cylinder to rotate around the central line of the inner cylinder.

Before sludge granulation, firstly carrying out innocent treatment to remove sulfite and cyanide particles, adding an acid solution into the caffeine wastewater, wherein the acid solution is selected from dilute hydrochloric acid, dilute sulfuric acid or carbonic acid, reacting the acid solution with the sulfite particles, and then carrying out blow-off treatment to obtain a solution from which sulfite ions are removed; adding an oxidant into the solution, wherein the oxidant is selected from hydrogen peroxide, sodium hypochlorite or ozone, and cyanide ions react with the oxidant to obtain wastewater without cyanide ions, and simultaneously, the color of the caffeine wastewater is removed.

According to the sludge granulation method in the caffeine production, a first dry powder dusting mechanism and a second dry powder dusting mechanism are additionally arranged in the screw conveying extruder, the second dry powder dusting mechanism is positioned at the upper part of the outer barrel cutting mechanism, and the dry powder is a powdery mixture of fly ash, quicklime or straw powder; the second dry powder agent dusting mechanism scatters the dry powder agent on the surface of the massive sludge through the brushing action of the material brush so as to reduce the water content ratio and facilitate the rolling of the massive sludge; the rotary power of the second dry powder dusting mechanism is provided by a fourth motor; the first dry powder dusting mechanism is positioned at the feed end of the screw conveying extruder, has the same structure as the second dry powder dusting mechanism, is driven by a third motor to rotate, and scatters the dry powder on the sludge entering the screw conveying extruder for mixing; the dry powder agent is a powdery mixture of quicklime and fly ash.

According to the sludge granulation method in the caffeine production, the hot air drying part is additionally arranged and comprises a hot air fan and a hot air pipe inserted into a central hole in the bottom of the inner cylinder, the hot air pipe blows hot air into the inner cylinder, the wall of the inner cylinder is provided with densely distributed small radiating air holes, and the hot air blown out of the small radiating air holes further dries and shapes the blocky sludge.

A sludge granulation mechanism in caffeine production comprises a base, a sludge strip making part and a sludge granulation part, wherein the sludge strip making part extrudes sludge into sludge strips, and the sludge strips enter the sludge granulation part to be granulated; the sludge granulation part comprises a cutting mechanism, a material receiving bulge, an outer cylinder, an inner cylinder, a spiral slideway and a finished product box; the outer cylinder and the inner cylinder are arranged on the annular support, the outer wall of the inner cylinder is provided with a spiral slideway, the upper port of the spiral slideway is in osculating connection with the bottom surface of the material receiving bulge above the spiral slideway, and the lower end of the spiral slideway passes through the cylinder wall of the inner cylinder and is osculating connected with a discharging cylinder at the center of the inner cylinder, so that sludge particles are guided into a finished product box; the cutting mechanism is arranged above the material receiving hump, and the periphery of the cutting mechanism is fixed with the outer cylinder; the lower end parts of the outer cylinder and the inner cylinder are rotatably supported on the annular rotating mechanism and are driven to rotate by a second motor through a pinion.

In the sludge granulating mechanism in caffeine production, the sludge strip making part comprises a screw conveying extruder, a first motor and a sieve plate, the screw conveying extruder is driven by the first motor to rotate, a main shaft of the screw conveying extruder is provided with a screw, the screw pitch of the screw is gradually reduced from left to right, and the extruded sludge is prepared into sludge strips through the sieve plate and falls into the sludge granulating part; the cutting mechanism is cutters which are arranged in a radial mode, the cutters are steel wires, the diameter of each steel wire is 0.5-2 mm, the number of the steel wires is 3-10, and the steel wires are evenly distributed at intervals.

The sludge granulating mechanism in the caffeine production is additionally provided with a first dry powder dusting mechanism and a second dry powder dusting mechanism, wherein the first dry powder dusting mechanism is positioned at the upper part of the outer cylinder and comprises a powder feeding hopper, an air avoiding valve and a powder dusting cylinder, the upper part of the air avoiding valve is connected with the powder feeding hopper, the lower part of the air avoiding valve is connected with the powder dusting cylinder, 4-10 material brushes are arranged in the powder dusting cylinder, and the material brushes disperse the powder fed into the powder dusting cylinder by the air avoiding valve and scatter the powder on sludge particles on the material receiving convex humps; the structure of the second dry powder dusting mechanism is the same as that of the first dry powder dusting mechanism, the second dry powder dusting mechanism is installed on the right side of the feeding hopper on the screw conveying extruder, the first dry powder dusting mechanism is driven by a third motor, the second dry powder dusting mechanism is driven by a fourth motor, and the dry powder is dusted on sludge entering the screw conveying extruder to be mixed.

The sludge granulating mechanism in caffeine production is characterized in that the annular support is composed of a cover plate, a ball and a base, the cover plate and the base are annular, an annular groove is formed in the opposite surface of the cover plate and the base, and the ball is arranged in the groove.

The sludge granulation mechanism in the caffeine production is additionally provided with a hot air drying system, the hot air drying system comprises a hot air fan, a hot air pipe and small radiating air holes uniformly distributed on the wall of an inner cylinder, the hot air pipe is fixed on the base, one end of the hot air pipe extends into the inner cylinder, the other end of the hot air pipe is connected with the hot air fan through a pipeline, and the temperature of hot air is selected to be 55-85 ℃.

The sludge granulation mechanism in the caffeine production is characterized in that a sludge particle uniformity adjusting piece is fixedly arranged at the central part of the sieve plate, the sludge particle uniformity adjusting piece is a hollow hemisphere, and the center of the sphere of the sludge particle uniformity adjusting piece is positioned on an extension line of the central line of the inner cylinder.

Advantageous effects

Compared with the prior art, the invention has the following advantages:

A. all the procedures are automated, including feeding, powder feeding, cutting, rolling, heating, drying and shaping, and the finished products fall into a finished product box, so that continuous production is realized;

B. the invention is provided with the dusting mechanism, can absorb water and dry the sludge, reduce the water content, make the sludge granule dry and wet properly, easy to shape, apparent quality is stable;

C. the spiral slideway is arranged, so that the rolling shaping process of sludge particles is prolonged, the sludge particles are more smooth and firm in appearance, the heating drying time is long, and the sludge particles are ensured to be shaped stably;

D. the finished sludge has uniform and consistent particles and good product phase, and is convenient for subsequent treatment and application;

E. the sludge granulation device provided by the invention is convenient to operate, small in occupied space and capable of realizing continuous automatic production, and the production efficiency of sludge granulation is greatly improved.

Drawings

The present invention will be described in further detail with reference to the drawings.

FIG. 1 is a schematic view of the structure of a granulating apparatus according to the present invention;

FIG. 2 is a schematic view of the transmission portion of the construction of the powdering device;

FIG. 3 is a cross-sectional view of FIG. 2 taken perpendicular to the plane of the drawing;

FIG. 4 is a schematic layout of discharge holes on a sieve plate;

FIG. 5 is a cross-sectional view of the cutter;

FIG. 6 is a top view of FIG. 5;

fig. 7 is a cross-sectional view of a receiving dome.

In the drawings, the reference numerals are respectively given as: 1. a first motor, 2, a feed hopper, 3, a transmission shaft, 4, a second dry powder dusting mechanism, 5, a powder feeding hopper, 6, the first dry powder dusting mechanism, 7, a sieve plate, 8, a cutter, 9, a material receiving bulge, 10, an outer cylinder, 11, an inner cylinder, 12, a spiral slideway, 13, an annular big gear, 14, a small gear, 15, a second motor, 16, a ball, 17, a hollow hemisphere, 18, a base, 19, a finished product box, 20, a hot air fan, 21, a hot air pipe, 22 and a second transmission shaft, 23, a table panel, 24, a cover plate, 25, a discharge hole, 26, a small heat dissipation air hole, 27, a powder outlet, 28, a material brush, 29, an annular support, 30, sludge particles, 31, a third motor, 32, a fourth motor (not shown), 33, a discharge cylinder, 601, a wind-avoiding valve, 602, a powder feeding hopper, 603, a powder scattering cylinder, 604, a driven shaft, 605, a driven wheel, 606, a driving wheel, 901, a crown-shaped bulge, 902, an annular rail, 903 and a discharge hole.

Detailed Description

The invention is further described in detail below with reference to the figures and examples.

Before granulation, the caffeine sludge is firstly subjected to primary harmless treatment to remove virulent components and harsh colors, and sulfite and cyanide particles are removed according to the following procedures. Adding an acid solution into the caffeine wastewater, wherein the acid solution is selected from dilute sulfuric acid, carbonic acid or acetic acid, the acid solution reacts with sulfite particles, and then carrying out blow-off treatment to obtain a solution from which sulfite ions are removed. Adding an oxidant into the solution, wherein the oxidant is selected from hydrogen peroxide, sodium hypochlorite or ozone, and cyanide ions react with the oxidant to obtain wastewater without cyanide ions, and simultaneously, removing dazzling red color of the caffeine wastewater.

The wastewater without cyanide and color enters a dehydration process, a conditioner can be added to stir the sludge before the sludge is dehydrated, the addition amount of the conditioner is 0.15-0.3% of the dry solid mass of the sludge, and the conditioning mode is mechanical stirring for 10-20 minutes. The conditioning agent is polyacrylamide. The conditioner can also be mixed with lignocellulose, the grain diameter of the lignocellulose is less than 0.5mm, and the mixing amount of the lignocellulose is 15-30% of the dry solid mass of the sludge. The lignocellulose is one or a mixture of bagasse, wood chips or straws.

Sludge dewatering: taking sludge discharged from a secondary sedimentation tank, adding a conditioner cationic polyacrylamide accounting for 0.15% of the dry solid mass of the sludge into the sludge with MLVSS/MLSS = 0.68, and stirring for 15min to obtain conditioned sludge; and adding straw accounting for 20% of the mass of the dry sludge, dehydrating, and reducing the water content of the sludge to 80% after mechanical filter pressing.

Then, the sludge is sent into a screw conveying, extruding, dicing and granulating machine to prepare granular sludge. In the device, the dehydrated sludge is extruded out of a sieve plate 7 with the aperture of 5-10mm by the continuous rotation of a spiral conveying extrusion main shaft, and cylindrical sludge particles are obtained after cutting by a cutter and fall in a spiral slideway below a discharge port for rolling and molding. The shape of the sludge particles is continuously corrected in the rolling process on the spiral slideway, the length of the raceway is designed to be capable of forming spherical particles, the size and the compactness of the spherical particles can meet requirements, and at the moment, the spherical particles roll out of the spiral slideway and fall into a finished product box 15.

The granulated sludge still contains a large amount of organic matters, nitrogen, phosphorus, potassium and trace elements, and various chemical substances, active bacteria, microorganisms and the like, and can be completely used as activated sludge seed sludge in wastewater treatment and also used as a filling material or a building material.

The sludge granulation device comprises sludge dewatering, screw conveying, extruding, block cutting, spherical granulation and other parts, all the processes can completely realize automatic production, the industrial continuous production is convenient, the processing cost is low, the discharging is fast, the activity of granular sludge is high, and the produced spherical granular sludge can be directly used as granular sludge seed sludge.

Referring to fig. 1, the invention comprises a base 18, a sludge strip making part and a sludge granulating part, wherein the sludge strip making part and a first motor 1 are fixed on a table board 23, the sludge strip making part extrudes sludge into sludge strips, and the sludge strips enter the sludge granulating part to be prepared into granules. The sludge granulation part comprises a dicing mechanism, material receiving convex humps 9, an outer cylinder 10, an inner cylinder 11, a spiral slideway 12 and a finished product box 19; the outer cylinder 10 and the inner cylinder 11 are arranged on the annular support 29, the outer wall of the inner cylinder 11 is provided with a spiral slideway 12, the upper port of the spiral slideway 12 is matched with a discharge port 903 at the bottom surface of a material receiving bulge 9 above the spiral slideway 12, and the lower end of the spiral slideway 12 passes through the cylinder wall of the inner cylinder 11 to be matched with a discharge cylinder 33 at the center of the inner cylinder, so that sludge particles are guided into the finished product box 19; the cutting mechanism is arranged above the material receiving hump 9, and the periphery of the cutting mechanism is fixed with the outer cylinder; the lower ends of the outer cylinder 10 and the inner cylinder 11 are rotatably supported by a ring rotating mechanism and are driven to rotate by a second motor 15 through a pinion 14. The working principle is as follows: open driving motor, mud system strip part is sent into to the mud after will dewatering, and mud is made the mud strip through the discharge opening of the screen 7 upper density cloth under the auger delivery extrusion, and the mud strip is cut into the cubic by the stripping and slicing machine, falls into on the material receiving bulge of rotatory mud granulation part, and annular rotary mechanism drives the high-speed rotation of mud granulation part, and cubic mud rolls along spiral slideway after receiving the discharge gate that the bulge landing rolled to the bottom, at the landing in-process, inner tube 11 drives spiral slideway 12 is also rotatory, spiral slideway 12's direction of rotation with inner tube 11 turns to conversely, and this has just reduced the bonding and the stop of cubic mud to roll the collision and become the graininess all the way in rotatory spiral slideway, fall into the finished product case.

Referring to fig. 1 and 5, the sludge strip making part comprises a screw conveying extruder, a first motor 1 and a sieve plate 7, the screw conveying extruder is driven by the first motor 1 to rotate, a screw is arranged on a main shaft of the screw conveying extruder, the screw pitch of the screw is gradually reduced from left to right, and the extruded sludge is made into sludge strips through the modulation of discharge round holes arranged on the sieve plate 7 and falls into the sludge granulating part. The screw pitch is gradually reduced from left to right, so that the volume of the spiral cavity is continuously contracted, the internal pressure at the sludge outlet is gradually increased, and the sludge smoothly reaches the discharge position and is extruded from the discharge hole.

The sludge granulation part is provided with a cutting mechanism which is a cutter 8 arranged in a radial shape, the cutter is a steel wire, the diameter of the steel wire is 0.5-2 mm, the number of the steel wire is 3-10, and the steel wire is uniformly distributed at intervals. The cutter uses thin steel wires to reduce the stress area of the sludge strips, increase the pressure intensity and reduce the required cutting force. The uniformly distributed cutters can uniformly cut the sludge strips.

Referring to fig. 1-3, the present invention provides a first dry powder dusting mechanism 6 and a second dry powder dusting mechanism 4, the second dry powder dusting mechanism 4 being located at an upper portion of the outer housing 10, the first dry powder dusting mechanism 6 and the second dry powder dusting mechanism 4 shown in fig. 1 being drawn with different directional views of the same component. Each component includes a hopper 602, a damper 601 and a dusting cylinder 603. The upper part of the wind-proof valve 601 is connected with a powder feeding hopper 602, and the lower part is connected with a powder spreading cylinder 603. 4-10 material brushes 28 are arranged in the powder scattering cylinder 603, and the material brushes 28 scatter the powder sent into the powder scattering cylinder 603 by the air damper 601 and scatter the powder on the sludge particles 30 on the material receiving humps 9. The material brush 28 is arranged to match the uniformly distributed powder outlet holes at the powder outlet 27 with the material brush 28, so that the scattered powder can be uniformly scattered on the sludge particles, and the water absorption and drying effects are better. The first dry powder dusting mechanism 6 has the same structure as the second dry powder dusting mechanism 4, is arranged on the right side of the feed hopper 2 on the screw conveying extruder, and is driven by a third motor 31 to scatter dry powder on sludge entering the screw conveying extruder for mixing. The dry powder falls into a powder spreading cylinder through the uniform speed scattering of the running wind shielding valve, the rotary material brush sweeps the dry powder down through the material receiving bulge below the sieve mesh, and the dry powder is adhered to the surface of the small mud block in the material receiving bulge to prevent the small mud block from being adhered.

Referring to fig. 1, the present invention is provided with a ring rotating mechanism on which the lower end portions of the outer cylinder 10 and the inner cylinder 11 are rotatably supported; the outer cylinder 10 and the inner cylinder 11 are provided with a rotary driving part, the rotary driving part comprises an annular large gear 13 and a small gear 14, and the small gear 14 drives the annular large gear 13 and further drives the outer cylinder 10 and the inner cylinder 11 to rotate around the central line of the inner cylinder 11.

The annular support 29 provided by the invention is composed of a cover plate 24, a ball 16 and a base 18, wherein the cover plate 24 and the base 18 are both annular, annular grooves are formed in the opposite surfaces of the cover plate 24 and the base 18, and the ball 16 is arranged in the grooves. The annular support 29 has the advantage of large bearing capacity, and can ensure that the sludge granulation part runs stably.

Referring to fig. 1, the present invention is further provided with a hot air drying system, the hot air drying system includes a hot air blower 20, a hot air pipe 21 and an inner cylinder 11, the wall of the inner cylinder 11 is uniformly distributed with small heat dissipating holes 26, the hot air pipe 21 is fixed on the base 18, one end of the hot air pipe extends into the inner cylinder 11 (deeply), and the other end of the hot air pipe is connected to the hot air blower 20 through a pipeline. The temperature of the hot air is selected from 50-85 ℃. The hot air conveyed by the hot air fan is dissipated from the heat dissipation holes, so that the inner barrel and the outer barrel are both provided with hot air, and sludge particles sliding down along the spiral slideway are dried, shaped and fall into a finished product box. The hot air pipe 21 is fixed on the base 18, so that the accident caused by the rotation and winding of the hot air pipe 21 along with the inner cylinder 11 is avoided.

Referring to fig. 1 and 5, a sludge particle uniformity adjusting member is arranged at the central part of the sieve plate 7, the sludge particle uniformity adjusting member is a hollow hemisphere 17, and the center of the sphere is positioned on the extension line of the central line of the inner cylinder 11. Avoid mud to pile up, make mud fall down from its peripheral discharge opening smoothly, the centre of sphere is located the extension line of inner tube central line, avoids the stripping and slicing machine center, prevents to mud strip cutting inhomogeneous. Moreover, the larger the diameter of the hollow hemisphere 17, the smaller the difference in size of the sludge block cut therefrom.

Claims

1. A sludge granulation method in caffeine production is characterized in that cyanoacetic acid and dimethyl urea are used as raw materials, acetic anhydride is used as a dehydrating agent to carry out a series of reactions to prepare caffeine, sludge discharged in caffeine production is dehydrated and then enters a sludge granulation process and is sent into a screw conveying extruder, a sieve plate is arranged at the lower part of the right end of the screw conveying extruder, extruded sludge is prepared into sludge strips through the sieve plate, and the sludge strips are cut into blocks by a cutting mechanism and fall into a sludge granulation part; the sludge granulation part is a rotary outer cylinder (10), an inner cylinder (11) with a slightly smaller diameter is sleeved in the outer cylinder (10), the upper part of the inner cylinder (11) is provided with a material receiving bulge (9), the bottom surface of the material receiving bulge (9) is connected with a spiral slideway (12), the spiral slideway (12) is spirally configured along the outer wall of the inner cylinder (11), and after the sludge granulation part rotates for a plurality of circles, the lower part of the sludge granulation part is gradually bent to enter the center of the inner cylinder (11) and extend out of the bottom of the inner cylinder (11); the blocky sludge falling into the sludge granulation part slides to the bottom from the material receiving bulge (9) and then rolls along the spiral slideway (12), and rolls into granules all the way and falls into a finished product box (19); the lower end parts of the outer cylinder (10) and the inner cylinder (11) are rotatably supported on the annular rotating mechanism; the outer cylinder (10) and the inner cylinder (11) are provided with rotary driving parts, each rotary driving part comprises an annular large gear (13) and a small gear (14), and the small gear (14) drives the annular large gear (13) and further drives the outer cylinder (10) and the inner cylinder (11) to rotate around the center line of the inner cylinder (11).

2. The method of sludge granulation in caffeine production according to claim 1, wherein before sludge granulation, a detoxification treatment is first performed to remove sulfite and cyanide particles, an acid solution selected from dilute hydrochloric acid, dilute sulfuric acid or carbonic acid is added to the caffeine waste water, the acid solution reacts with the sulfite particles, and then a stripping treatment is performed to obtain a solution from which sulfite ions are removed; adding an oxidant into the solution, wherein the oxidant is selected from hydrogen peroxide, sodium hypochlorite or ozone, and cyanide ions react with the oxidant to obtain wastewater without cyanide ions, and simultaneously, the color of the caffeine wastewater is removed.

3. The sludge granulation method in the caffeine production according to claim 1, wherein a first dry powder dusting mechanism (6) and a second dry powder dusting mechanism (4) are additionally arranged in the screw conveyer extruder, the second dry powder dusting mechanism (4) is positioned at the upper part of the outer barrel (10) cutting mechanism, and the dry powder is a powdery mixture of fly ash, quicklime or straw powder; the second dry powder agent dusting mechanism (4) scatters the dry powder agent on the surface of the massive sludge through the brushing action of the material brush (28) so as to reduce the water content ratio and facilitate the rolling of the massive sludge; the rotational power of the second dry powder dusting mechanism (4) is provided by a fourth motor (32); the first dry powder dusting mechanism (6) is positioned at the feed end of the screw conveying extruder, has the same structure as the second dry powder dusting mechanism (4), is driven by a third motor (31) to rotate, and is used for dusting the dry powder on the sludge entering the screw conveying extruder for mixing; the dry powder agent is a powdery mixture of quicklime and fly ash.

4. The sludge granulation method in the caffeine production according to claim 1, wherein a hot air drying part is added, the hot air drying part comprises a hot air blower (20) and a hot air pipe (21) inserted into a central hole at the bottom of the inner cylinder (11), the hot air pipe (21) blows hot air into the inner cylinder (11), densely distributed small heat dissipation holes (26) are formed in the wall of the inner cylinder (11), and the block sludge is further dried and shaped by the hot air blown out of the small heat dissipation holes (26).

5. A sludge granulation device in caffeine production is characterized in that: the sludge strip making machine comprises a base (18), a sludge strip making part and a sludge granulating part, wherein the sludge strip making part extrudes sludge into sludge strips, and the sludge strips enter the sludge granulating part to be made into granules; the sludge granulation part comprises a cutting mechanism, a material receiving bulge (9), an outer cylinder (10), an inner cylinder (11), a spiral slideway (12) and a finished product box (19); the outer cylinder (10) and the inner cylinder (11) are arranged on the annular support (29), the outer wall of the inner cylinder (11) is provided with a spiral slideway (12), the upper port of the spiral slideway (12) is in butt joint with a discharge hole (903) at the bottom surface of a material receiving bulge (9) above the spiral slideway, and the lower end of the spiral slideway (12) penetrates through the cylinder wall of the inner cylinder (11) and is in butt joint with a discharge cylinder (33) at the center of the inner cylinder, so that sludge particles are guided into the finished product box (19); the cutting mechanism is arranged above the material receiving hump (9), and the periphery of the cutting mechanism is fixed with the outer cylinder; the lower end parts of the outer cylinder (10) and the inner cylinder (11) are supported on the annular rotating mechanism and are driven to rotate by a second motor (15) through a pinion (14).

6. The apparatus of claim 5, wherein: the sludge strip making part comprises a screw conveying extruder, a first motor (1) and a sieve plate (7), the screw conveying extruder is driven by the first motor (1) to rotate, a screw is arranged on a main shaft of the screw conveying extruder, the screw pitch of the screw is gradually reduced from left to right, and the extruded sludge is made into sludge strips through the modulation of the sieve plate (7) and falls into the sludge granulation part; the cutting mechanism is cutters (8) arranged in a radial mode, the cutters (8) are steel wires, the diameter of each steel wire is 0.5-2 mm, the number of the steel wires is 3-10, and the steel wires are evenly distributed at intervals.

7. The sludge granulating device in the caffeine production according to claim 6, wherein a first dry powder dusting mechanism (6) and a second dry powder dusting mechanism (4) are additionally arranged, the second dry powder dusting mechanism (4) is positioned at the upper part of the outer barrel (10) and comprises a powder feeding hopper (602), an air-shielding valve (601) and a dusting barrel (603), the upper part of the air-shielding valve (601) is connected with the powder feeding hopper (602), the lower part of the air-shielding valve is connected with the dusting barrel (603), 4-10 material brushes (28) are arranged in the dusting barrel (603), and the material brushes (28) disperse the powder fed into the dusting barrel (603) by the air-shielding valve (601) and scatter the powder on the sludge particles on the material receiving bulge (9); the structure of the first dry powder dusting mechanism (6) is the same as that of the second dry powder dusting mechanism (4), the first dry powder dusting mechanism (6) is installed on the right side of the feeding hopper (2) on the screw conveying extruder, and the first dry powder dusting mechanism (6) is driven by a third motor (31) to scatter dry powder on sludge entering the screw conveying extruder for mixing.

8. A sludge granulator for caffeine production according to claim 6, wherein the annular support (29) comprises a cover plate (24), balls (16) and a base (18), the cover plate (24) and the base (18) are both annular, and annular grooves are provided on the opposite surfaces of the cover plate (24) and the base (18), and the balls (16) are installed in the grooves.

9. The sludge granulating device in the production of caffeine according to claim 6, wherein a hot air drying system is added, the hot air drying system comprises a hot air blower (20), a hot air pipe (21) and an inner cylinder (11), the wall of the inner cylinder (11) is fully distributed with uniformly arranged small heat dissipation holes (26), the hot air pipe (21) is fixed on the base (18), one end of the hot air pipe extends into the inner cylinder (11), the other end of the hot air pipe is connected with the hot air blower (20) through a pipeline, and the temperature of hot air is selected to be 55-85 ℃.

10. A sludge granulator in caffeine production according to claim 6, wherein a sludge particle (30) uniformity adjusting member is fixed in the center of the sieve plate (7), the sludge particle (30) uniformity adjusting member is a hollow hemisphere (17), the center of which is located on the extension line of the center line of the inner cylinder (11).