CN213012531U - Sludge drying and dewatering equipment - Google Patents

Abstract

The utility model belongs to solid abandonment resource utilization field relates to a sludge drying dewatering equipment. The equipment comprises a 1# conveying device (1), a buffer bin (2), a 2# conveying device (3), a rotary drum indirect drying device (4), a screening device (5), a dry sludge storage device (6), a 3# conveying device (7) and a waste heat recovery device (8); the 1# conveying device (1) and the 2# conveying device (3) are communicated with the buffer bin (2); the buffer bin (2), the rotary drum indirect drying device (4) and the screening device (5) are communicated in sequence; oversize materials of the screening device (5) are conveyed into a waste heat recovery device (8) through a 3# conveying device (7); the materials in the waste heat recovery device (8) are conveyed back to the buffer bin (2) through the No. 2 conveying device (3). The utility model provides an equipment dehydration is efficient, and energy resource consumption is low, and can effectively avoid the direct mummification of mud easily to harden, easily appear gluing the wall problem.

Description

Sludge drying and dewatering equipment

Technical Field

The utility model belongs to solid abandonment resource utilization field, concretely relates to sludge drying dewatering equipment.

Background

In recent years, with the promotion of industrialization and the continuous increase of population, the number of sewage treatment plants is continuously increased, the sludge production is estimated to exceed 7000 million tons in 2020 years in China, and the annual average annual growth rate is estimated to exceed 11%. The wet sludge contains free water, interstitial water, surface water and chemically combined water, the water content of the wet sludge is still as high as 70-85% after the free water and the interstitial water are removed by a common dehydration process, and the water is attached to the surfaces of particles through hydrogen bonds, so that the problems of difficult sludge treatment and high resource cost are caused. The domestic sludge recycling technology comprises landfill, composting, incineration, pyrolysis treatment and the like. However, either technique is intended to solve the sludge dewatering problem first. Therefore, dehydration is an important link for realizing sludge reduction, harmlessness and recycling, and the development of a novel sludge drying treatment technology is urgent.

At present, the thermal drying dehydration of the sludge usually adopts steam, high-temperature flue gas, microwave or heated heat conducting oil or even solar energy and the like as heat sources, adopts a direct or indirect heating mode and is assisted by mixing and stirring to realize the dehydration purpose. The direct heat transfer type sludge drying mostly uses high-temperature flue gas or air as a heat source, so that the high-temperature flue gas or the air is directly contacted with wet sludge after entering a dryer, and the tail gas carries out moisture evaporated from the wet sludge. Although the dehydration efficiency is higher, the flue gas is polluted by sludge and volatile matters thereof due to the direct contact of the flue gas and wet sludge, so that secondary pollution such as odor, dust and the like is caused, a tail gas purification system is complex, the investment is larger, and the operation cost is higher. CN201810142297.3 discloses a sludge drying apparatus and a sludge drying method, in which a conveyor belt is attached to sludge and wound around a plurality of support rollers to form a closed conveying path, so as to increase the contact area between the sludge and air, and to allow the sludge to have a sufficient time for drying, thereby increasing the drying rate of the sludge. CN201820528539.8 discloses a low temperature belt sludge drying device, is provided with the second conveyer belt in the inside below in sludge drying chamber, and adsorbs the phenol that volatilizees in the comdenstion water through the active carbon filter layer in the comdenstion water purification tank, discharges the comdenstion water catch basin again, has prevented that phenol from volatilizing and causing secondary pollution in the air. CN201721219838.5 discloses a sludge drying machine system, which comprises a sludge drying machine and a host machine for providing airflow for drying sludge for the sludge drying machine, wherein the sludge drying machine and the host machine form a closed sludge drying environment, and the sludge drying machine and the host machine are matched with an extrusion molding part of the sludge and a sludge overturning drying process to complete a sludge drying process in the closed sludge drying machine. Because the flue gas or air used for heating in the method needs to be directly contacted with the sludge, the equipment volume and the occupied area are large, the tail gas contains pollutants, and the purification cost is higher although the thermal efficiency is high.

In the indirect heat transfer type sludge drying and dehydrating process, the sludge is not directly contacted with the heating medium, so that the flue gas and the tail gas are not polluted by the sludge, and the purification system is simple. But because the space of the heating furnace is limited, the energy utilization efficiency of the existing indirect drying system is not high, and the situations of uneven sludge drying and low dehydration efficiency are easy to occur. CN201920005394.8 discloses a cement kiln sludge drying equipment, including indirect drying device, direct drying device and pipeline, wherein the indirect drying device communicates with direct drying device through pipeline, and direct drying device is used for receiving the mud of indirect drying device output and with it and cement kiln high temperature flue gas contact realization mummification. Although the method realizes the gradient utilization of energy by connecting the indirect drying mode and the direct drying mode in series, the energy efficiency is improved limitedly and the environmental problem caused by the direct drying mode can not be avoided because the flue gas has larger volume, short retention time and poor sludge heat conduction effect. In addition, some techniques disclose that the efficiency of sludge drying and dewatering is improved by adding a disturbance device or by forming and granulating. If CN201811295909.9 discloses a sludge drying machine, including one-level, second grade sludge drying device, wherein second grade sludge drying device includes outer barrel and interior barrel, installs the pivot in the inner barrel, and pivot one end intercommunication has the motor and installs stirring pusher in the pivot along length direction, and stirring pusher includes a plurality of stirring rods along pivot surface evenly distributed. CN201711196183.9 discloses a sludge drying treatment method and a device, wherein sludge subjected to simple air drying and precipitation treatment is conveyed to a roller press by a feeding machine to be rolled into a thin sludge cake, the thin sludge cake is cut into strips by a serrated knife forming machine, and then the strips are conveyed to a stirring type dryer to be heated and turned for many times, so that sludge drying treatment is realized. However, the above device has a relatively complex structure, the improvement on the energy utilization efficiency is limited, and the secondary pollution problem still exists in part of links along with the exhaust emission of the waste heat of a large amount of heating media.

Researchers have pretreated wet sludge to achieve the purpose of improving the sludge drying efficiency. CN1884154A discloses a sludge carrier drying process, mixing pretreated sludge and sludge dry powder according to the mass ratio of 1:1-5, and stirring at high speed to achieve characteristic conditioning; aerobic curing, stacking the conditioned sludge in a storage yard, turning and stirring for 1 time every 6-10 hours until the water content of the sludge is 20-25%, and sending the sludge into a hot air system for drying. In the method, a large field is needed for aerobic curing, and the difficulty and the time for reaching the sludge moisture content of 20-25 percent through natural drying are large. CN101224912B discloses a drying method capable of treating sludge with different water contents, which comprises the following steps: (1) firstly, drying the dewatered sludge to be used as a sludge drying carrier; (2) respectively conveying the sludge drying carrier and the dehydrated sludge to be dried to a stirring and mixing device for stirring and mixing to obtain mixed sludge; (3) conveying the mixed sludge into a drying device for drying; (4) repeating the steps (2) and (3); taking out the mixed sludge output from the stirring and mixing device in the step (4) according to the sludge carrier amount required in drying from the mixed sludge, and inputting the sludge into a drying device for drying to form a sludge drying carrier; the rest is used as the final product. The method adopts the mixing and drying of the dry sludge and the wet sludge, and has no disturbance and crushing effect on the wet sludge due to fine particles of the dry sludge, so that the improvement degree of the drying efficiency of the wet sludge is not high.

In conclusion, the sludge has large viscosity and is difficult to disperse, the mass transfer and heat transfer efficiency during thermal drying is low, and the moisture drying and removing difficulty is large. Therefore, a new drying mode is required to be found, the sludge drying efficiency is improved and the drying cost is reduced by an internal and external heating cooperative working mode, and the method has important significance for sludge reduction and resource utilization.

Disclosure of Invention

The utility model aims at overcoming the dehydration difficulty that exists when adopting current equipment to carry out the drying dehydration to wet mud, the energy consumption is big, dehydration inefficiency just harden scheduling problem at the drying cavity easily, and provide one kind can improve dehydration efficiency and energy efficiency to can effectively avoid the drying dehydration equipment of indirect mummification heating inequality of mud, easily harden and glue wall scheduling problem.

The utility model discloses the rationale is that the flue gas tail gas waste heat that abundant recovery mud indirect drying produced heats the heat accumulation ball to send into indirect drying device after mixing heat accumulation ball after will heating with wet mud, when carrying out outside indirect heating drying dehydration, utilize heat accumulation ball and wet mud direct contact drying, through ball-milling disturbance and inside and outside concurrent heating's mode, change mud gel structure, the moisture that is confined in making the mud micelle is fully released, reach the quick broken wall of cell that contains water in the mud, the high-efficient mummification of moisture target. Compared with the existing sludge drying treatment technology, the method can well solve the problems of fine sludge particles, high viscosity, difficult dehydration, easy hardening during drying and the like, greatly saves the treatment cost and reduces the equipment investment. The utility model discloses realize inside and outside drying in coordination of rotary drum, possess indirect dry's environmental protection advantage and direct dry's energy efficiency simultaneously, show to have reduced the sludge dewatering cost.

Specifically, the utility model provides a sludge drying and dewatering equipment, wherein, sludge drying and dewatering equipment includes 1# conveyor, surge bin, 2# conveyor, rotary drum indirect drying device, screening plant, dry sludge storage device, 3# conveyor and waste heat recovery device; the No. 1 conveying device and the No. 2 conveying device are arranged at the top of the buffer bin and are respectively used for conveying wet sludge and heat storage balls into the buffer bin; a mixture outlet at the bottom of the buffer bin is communicated with a feeding port of the rotary drum indirect drying device, and a discharging port of the rotary drum indirect drying device is communicated with a feeding port of the screening device; introducing undersize products of the screening device into a dry sludge storage device, and conveying oversize products into a waste heat recovery device through a No. 3 conveying device; and materials in the waste heat recovery device are conveyed back to the buffer bin through the No. 2 conveying device.

Furthermore, the bottom of the buffer bin is provided with an inclined chute, and the mixture outlet of the buffer bin is positioned at the bottom end of the inclined chute.

Further, sludge drying and dewatering equipment still includes flue gas tail gas purifier, flue gas fan and chimney, waste heat recovery device's exhanst gas outlet and flue gas tail gas purifier's flue gas entry intercommunication, the flue gas after the purification is pumped to the chimney through flue gas fan and is discharged up to standard.

Further, the indirect drying device of the rotary drum comprises the rotary drum, a flue gas pipeline, a gas fan, a burner and a hearth, the rotary drum is arranged in the hearth, a flue gas outlet at the top of the hearth is communicated with a flue gas inlet of the waste heat recovery device through the flue gas pipeline, the burner is arranged at the bottom of the hearth and is arranged at the end part of the gas pipeline, and the gas fan is arranged on the gas pipeline; the gas is pumped to the end of the gas pipeline through the gas fan, is sprayed out through a burner arranged at the end of the gas pipeline, is burnt in the hearth as an indirect drying heat source, and the flue gas generated in the hearth is sent into the waste heat recovery device through the flue gas pipeline to heat the heat storage balls.

Further, sludge drying and dewatering equipment still includes steam pipe, steam condensing equipment, air conduit and air blower, the steam condensing equipment top is provided with water sprayer and the bottom is provided with the tank, the indirect drying device's of rotary drum vapor outlet passes through steam pipe and steam condensing equipment intercommunication, steam condensing equipment is used for condensing steam, and the gained comdenstion water is stored in the tank and is recycled, and gained noncondensable gas is pumped to furnace through air conduit and is used for combustion-supporting wind under air blower's effect.

Further, the sludge drying and dewatering device comprises: the system comprises a No. 1 conveying device, a buffer bin, a No. 2 conveying device, a rotary drum indirect drying device, a screening device, a dry sludge storage device, a No. 3 conveying device, a waste heat recovery device, a flue gas tail gas purification device, a flue gas fan, a chimney, a steam pipe, a steam condensing device, an air pipeline and an air fan; the indirect drying device of the rotary drum comprises the rotary drum, a flue gas pipeline, a gas fan, a burner and a hearth; the top of the steam condensing device is provided with a water sprayer and the bottom of the steam condensing device is provided with a water storage tank; the No. 1 conveying device and the No. 2 conveying device are arranged at the top of the buffer bin and are respectively used for conveying wet sludge and heat storage balls into the buffer bin; the bottom of the buffer bin is provided with an inclined chute which is communicated with a feeding port of the rotary drum indirect drying device, and a discharging port of the rotary drum indirect drying device is communicated with a feeding port of the screening device; introducing undersize products of the screening device into a dry sludge storage device, and conveying oversize products into a waste heat recovery device through a No. 3 conveying device; the materials in the waste heat recovery device are conveyed back to the buffer bin through the No. 2 conveying device; a steam outlet of the rotary drum indirect drying device is communicated with a steam condensing device through a steam pipe, the steam condensing device is used for condensing steam, the obtained condensed water is stored in a water storage tank for recycling, and the obtained non-condensed gas is pumped to a hearth through an air pipeline under the action of an air fan to be used as combustion-supporting air; the rotary drum is arranged in the hearth, the burner is arranged at the bottom of the hearth and at the end part of the gas pipeline, and the gas fan is arranged on the gas pipeline; the end of a gas pipeline is pumped by a gas fan, the gas is sprayed out through a burner arranged at the end of the gas pipeline and is combusted in a hearth as an indirect drying heat source, a top flue gas outlet of the hearth is communicated with a flue gas inlet of a waste heat recovery device through a flue gas pipeline, a flue gas outlet of the waste heat recovery device is communicated with a flue gas inlet of a flue gas tail gas purification device, and the purified flue gas is pumped to a chimney through the gas fan and is discharged up to the standard.

Further, the No. 1 conveying device is a single-shaft, double-shaft or shaftless screw conveyor or an embedded scraper conveyor.

Further, the No. 2 conveying device is a single-shaft, double-shaft or shaftless screw conveyor.

Furthermore, the buffer bin and the dry sludge storage device are common steel material bins.

Further, the heat-resistant temperature of the rotary drum indirect drying device is not lower than 400 ℃.

Furthermore, the heating mode of the rotary drum indirect drying device is indirect heating.

Further, the screening device is a vibrating screen or a rotary screen.

Further, the 3# conveying device is a large-inclination-angle belt conveyor, a bucket elevator or an embedded scraper conveyor.

Furthermore, the waste heat recovery device is a shaft furnace for directly contacting the heat storage ball body with the flue gas to exchange heat.

Further, the flue gas pipeline is a common flue gas pipeline.

Further, the flue gas tail gas purification device is a conventional dry method or semi-dry method flue gas purification device.

Further, the flue gas fan is a common high-temperature fan.

Further, the chimney is a steel chimney or a concrete chimney.

Further, the steam pipe is a common steel pipe.

Further, the steam condensing device is a common water condensing device.

Further, the water storage tank is a common steel or concrete water storage tank.

Further, the air pipeline is a common steel pipeline.

Further, the air fan is a common air induced draft fan.

Further, the gas pipeline is a common steel gas pipeline.

Further, the gas fan is a common gas fan.

Further, the combustor is a natural gas combustor, an oil gas combustor, a biomass pyrolysis gas combustor or a gas combustor.

Furthermore, the hearth is a common combustible gas combustion heating hearth.

Furthermore, the length-diameter ratio of a rotary drum of the rotary drum indirect drying device is (10-20): 1.

Furthermore, the inner wall of the rotary drum is provided with material raising plates which are opposite to the axis and are uniformly distributed along the periphery of the drum diameter at intervals of 30-60 degrees, and two adjacent rings of material raising plates are distributed in a staggered manner; the three sections are arranged along the moving direction of the materials, the front part 1/3 of the roller is a first section, the middle part 1/3 of the roller is a second section, and the rear part 1/3 of the roller is a third section; the number ratio of the three material raising plates is 1:2: 1.

Further, the lifting blade is the cuboid, and length is 5 ~ 15cm, length: width: the height is (3-5) 1: 0.1.

Compared with the prior art, the utility model discloses following beneficial effect has:

(1) mix hydrous mud and the heat accumulation spheroid after the heating, send into the indirect drying and heating cylinder of rotation jointly and carry out the indirect heating dehydration, carry out the broken disturbance of mud grinding when the heat accumulation spheroid carries out the direct contact heating dehydration to wet mud in the cylinder moreover, realize the high-efficient drying and dehydrating of mud through the mode of inside and outside concurrent heating, compare with current indirect drying method, drying efficiency can promote more than 15%.

(2) The sludge in the roller is disturbed, loosened and cleaned through the collision of the heat storage balls, so that the problems of dust deposition and sludge adhesion in the drying process of the conventional device are solved, and the problems of easy hardening, easy wall adhesion, low drying efficiency and the like in the sludge dewatering process are avoided; and the waste heat recovery of the flue gas tail gas that the indirect drying device of rotary drum produced is used for the heating of heat accumulation spheroid, realizes the high-efficient utilization of the energy, reduces the flue gas condensation cooling load of tail gas purification process simultaneously.

(3) When the device provided by the utility model is adopted for sludge drying and dewatering, the advantage of indirect drying can be fully exerted, the tail gas production is small, the purification is simple, and the pollution is small; and the heat storage balls are synchronously utilized to directly dry the sludge, so that the sludge drying device has the effect of direct drying, the energy utilization efficiency is greatly improved, the energy-saving benefit can be improved by more than 20%, and the concepts of circular economy, energy conservation and environmental protection are fully embodied.

(4) The utility model provides a sludge drying and dewatering equipment working costs is low, and the processing scale is big, and the investment is little, and the practicality is strong, and simple relatively, nimble of technology, and drying efficiency is high, has avoided the problem that current drying device exists completely, has apparent social, economic benefits and environmental benefit.

Drawings

Fig. 1 is a specific structural schematic diagram of the sludge drying and dewatering equipment provided by the utility model.

Fig. 2 is the utility model provides a schematic diagram of the arrangement of the lifting blade in the sludge drying dehydration equipment cylinder.

Description of the reference numerals

The system comprises a 1-1# conveying device, a 2-buffer bin, a 3-2# conveying device, a 4-rotary roller indirect drying device, a 5-screening device, a 6-dry sludge storage device, a 7-3# conveying device, an 8-waste heat recovery device, a 9-flue gas pipeline, a 10-flue gas tail gas purification device, an 11-flue gas fan, a 12-chimney, a 13-steam pipe, a 14-steam condensing device, a 15-water storage tank, a 16-air pipeline, a 17-air fan, an 18-fuel gas pipeline, a 19-fuel gas fan, a 20-combustor and a 21-hearth.

Detailed Description

As shown in fig. 1, the # 1 conveying device 1 and the # 2 conveying device 3 are respectively disposed above the surge bin 2. The No. 1 conveying device 1 is used for conveying wet sludge, and the No. 2 conveying device 3 is used for conveying heated heat storage balls.

The surge bin 2 is used for premixing wet sludge and heat storage balls, and the wet sludge is entrained by the heat storage balls to enter the rotary drum indirect drying device 4, so that the problem of difficult feeding of the wet sludge due to high viscosity can be well solved. The bottom of the buffer bin 2 is provided with an inclined chute, the mixture outlet of the buffer bin 2 is positioned at the bottom end of the inclined chute, wet sludge and heat storage balls are premixed in the buffer bin 2 and then slide into the rotary drum indirect drying device 4 through the inclined chute to be dried, and the inclined chute is more favorable for conveying mixed materials.

The indirect drying device 4 with the rotary drum comprises the rotary drum, a flue gas pipeline 9, a gas pipeline 18, a gas fan 19, a burner 20 and a hearth 21, the rotary drum is arranged inside the hearth 21, a flue gas outlet at the top of the hearth 21 is communicated with a flue gas inlet of the waste heat recovery device 8 through the flue gas pipeline 9, the burner 20 is arranged at the bottom of the hearth 21 and at the end of the gas pipeline 18, and the gas fan 19 is arranged on the gas pipeline 18; the gas is pumped to the end part of the gas pipeline 18 through the gas fan 19, is sprayed out through the burner 20 arranged at the end part of the gas pipeline 18, is burnt in the hearth 21 to be used as an indirect drying heat source, and the flue gas generated in the hearth 21 is sent into the waste heat recovery device 8 through the flue gas pipeline 9 to heat the heat storage balls. Wet sludge and heat accumulation ball carry out broken disturbance to wet sludge in sending into the indirect drying device 4's of rotary drum gyration cylinder jointly after 2 premixing in surge bin, through inside heat accumulation ball direct heating, outside rotary drum indirect heating's inside and outside collaborative mode not only can realize the high-efficient dehydration drying of wet sludge, can avoid the direct mummification of mud moreover easily to harden, the wall, drying efficiency low grade problem easily appear gluing. After the gas is combusted in the combustor 20, the flame directly heats the rotary drum indirect drying device 4, and then the generated heat is used for heating the rotary drum indirect drying device 4 in the heating hearth 21 to indirectly dry the sludge of the rotary drum. The water vapor evaporated in the rotary drum indirect drying device 4 enters a vapor condensing device 14 through a vapor pipe 13, the water sprayed by the spraying device is condensed, and condensed water generated by the condensation of the water vapor is stored and cooled in a water storage tank 15 and is circulated as water for the spraying device; non-condensable gas in the water vapor is conveyed into the hearth 21 through the air pipeline 16 and the air fan 17 for combustion supporting air to be used as air required by combustion of fuel of the combustor 20, and the problem of odor in the sludge drying process is thoroughly solved. The flue gas tail gas generated by the heating hearth 21 is input into a flue gas waste heat recovery device 8 through a flue gas pipeline 9, and the recovered waste heat is used for heating the heat storage balls, so that the high-efficiency utilization of energy is fully realized; the flue gas after heat exchange by the heat storage balls enters a flue gas tail gas purification device 10 for purification treatment, and the purified flue gas is pumped to a chimney 12 through a flue gas fan 11 and is discharged after reaching the standard. The heated heat storage balls are conveyed to the rotary drum indirect drying device 4 again through the No. 2 conveying device 3, and recycling is achieved.

The length-diameter ratio of a rotary drum of the rotary drum indirect drying device 4 is preferably (10-20) to 1, the length-diameter ratio is too large, the occupied area is large, and the investment is high; draw ratio undersize, on the one hand the little thermal efficiency that leads to indirect heating of cylinder heat transfer area is low, and on the other hand, heat accumulation ball is short with mud direct contact heating time in the cylinder, and the effect of inside and outside collaborative heating is not showing remarkably.

According to the utility model discloses a concrete implementation mode, as shown in fig. 2, be provided with the lifting blade on rotary drum's the inner wall, the lifting blade just to the axle center and along the barrel diameter evenly distributed all around, the interval is 30 ~ 60, and faces two rings of lifting blades mutually and be crisscross distribution. The three-stage roller is arranged along the moving direction (axial direction) of materials, the front part 1/3 of the roller is a first stage, the middle part 1/3 of the roller is a second stage, and the rear part 1/3 of the roller is a third stage; the number ratio of the three material raising plates is 1:2: 1. The first section is a feeding pre-drying section, the water content of the sludge is high, the viscosity is high, and the drying efficiency is further prevented from being influenced by the fact that the sludge is agglomerated and adheres to the heat storage balls, so that the arrangement number of the material raising plates is relatively small; the second section is a high-efficiency dehydration section, the number of the material raising plates is twice that of the first section and the third section, the water content of the sludge passes through a viscous region, the activity of the heat storage balls is good, the effect of raising, extruding and grinding the sludge can be enhanced after the number of the material raising plates is increased, the direct contact heat exchange of the heat storage balls is promoted, and the efficiency of the whole indirect heating system is improved; the sludge dewatering of the third section gradually reaches the target value, the viscosity of the dewatered sludge is low for the discharging preparation section, the air permeability is good, and the number of the lifting plates is reduced for avoiding a large amount of dust during discharging. The system for optimizing the number of the lifting blades considers key links such as material drying and dewatering characteristics, a heat storage ball disturbance grinding mechanism and roller indirect drying, and fully achieves the comprehensive aim of system energy conservation. In addition, the material raising plate can be a cuboid, the length of the material raising plate is 5-15 cm, and the ratio of the length to the width to the height of the material raising plate is preferably (3-5): 1: 0.1.

The undersize product of the screening device 5 is a dry sludge outlet and is communicated with a dry sludge storage device 6; oversize materials are heat storage balls and are conveyed into a waste heat recovery device 8 through a 3# conveying device 7; the heat storage balls are heated in the waste heat recovery device 8, so that waste heat utilization is realized. The diameter of a sieve pore of the screening device 5 is 30-60% of that of the heat storage ball; the sieve mesh has too large diameter, so that the ball clamping phenomenon is easy to occur, and the separation of the heat storage balls is not facilitated; and if the diameter of the sieve mesh is too small, the sieve mesh is easy to block due to large electrostatic adhesion of the sludge and small diameter of the sieve mesh, and the separation of the heat storage balls and the dewatered sludge is not facilitated. And under the action of vibration screening, the sludge on the outer surface of the heat storage ball with a smooth surface is completely removed, then is sent into a waste heat recovery device 8 through a 3# conveying device 7, and then is further returned into the buffer bin 2, so that the recycling is realized.

The waste heat recovery device 8 is used for heating the heat storage balls, and the heating heat source is preferably flue gas waste heat from the rotary drum indirect drying device 4, so that high-efficiency recycling of heat can be realized, and energy is saved. The temperature of the heated heat storage balls can reach 120-180 ℃, and the heat storage balls are returned to the buffer bin 2 through the 2# conveying device 3, so that recycling is realized.

The No. 1 conveying device 1 can be a single-shaft, double-shaft or shaftless screw conveyor or an embedded scraper conveyor.

The # 2 conveying device 3 can be a single-shaft, double-shaft or shaftless screw conveyor.

The surge bin 2 and the dry sludge storage device 6 can be common steel material bins.

The heat-resistant temperature of the rotary drum indirect drying device 4 is not lower than 400 ℃, and the heating mode is indirect heating.

The screening device 5 may be a vibrating screen or a drum screen.

The 3# conveying device 7 can be a large-inclination belt conveyor, a bucket elevator or an embedded scraper conveyor.

The waste heat recovery device 8 can be a shaft furnace for directly contacting and exchanging heat between the heat storage ball body and the flue gas.

The flue gas duct 9 may be a common flue gas duct.

The flue gas tail gas purification device 10 can be a conventional dry method or semi-dry method flue gas purification device.

The flue gas fan 11 may be a common high temperature fan.

The chimney 12 may be a steel or concrete chimney.

The steam pipe 13 may be a general steel pipe.

The steam condensing device 14 may be a common water condensing device, and the cooling manner may be direct condensation or indirect condensation. The steam condensing means 14 is preferably cooled by direct water spraying.

The reservoir 15 may be a common steel or concrete reservoir.

The air duct 16 may be a conventional steel duct.

The air blower 17 may be a common air induced draft fan.

The gas pipeline 18 may be a conventional steel gas pipeline.

The gas fan 19 may be a general gas fan.

The combustor 20 may be a combustor for combustible gas such as natural gas, petroleum gas, biomass pyrolysis gas or coal gas.

The furnace 21 can be a common gas combustion heating furnace.

The utility model provides a sludge drying dehydration method that equipment corresponds includes and handles in sending into above-mentioned sludge drying dehydration equipment wet mud and heat accumulation ball respectively in order to carry out drying dehydration to wet mud. Specifically, wet sludge and heat storage balls are conveyed into a buffer bin 2 through a No. 1 conveying device 1 and a No. 2 conveying device 3 respectively, then the wet sludge and the heat storage balls jointly enter a rotary drum indirect drying device 4 to be subjected to inside and outside synergistic drying and dehydration, dried materials are screened through a screening device 5, undersize materials are dried sludge and are directly conveyed into a dry sludge storage device 6, oversize materials are heat storage balls, the heat storage balls are conveyed into a waste heat recovery device 8 through a No. 3 conveying device 7 and are heated by smoke waste heat; flue gas that produces among the indirect drying device 4 of gyration cylinder is carried to waste heat recovery device 8 in via flue gas pipeline 9 to heat accumulation ball, heat accumulation ball after the heating is carried back to surge bin 2 again in via 2# conveyor 3, realizes recycling.

The wet sludge may be municipal sewage treatment plant sludge or industrial sewage treatment plant sludge. The moisture content of the wet sludge is preferably 90% or less, and may be, for example, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or the like.

The heat storage ball can be a conventional steel heat storage ball or a ceramic heat storage ball, and the compressive strength is greater than 1 MPa. The heat storage ball is preferably a high-aluminum heat storage ball or a mullite heat storage ball.

The shape of the heat storage balls may be a smooth-surfaced spherical shape. The diameter of the heat storage ball is preferably 0.5-2 cm, and more preferably 0.5-1 cm. When the particle size of the heat storage ball is overlarge (the diameter exceeds 2cm)When the heat storage ball is used, the volume is too large, the heat storage ball is not easy to convey, the number of the heat storage balls is small under the condition of the same mass, and the heat storage and heat exchange effects are poor; when the particle size of the heat storage ball is too small (the diameter is less than 0.5cm), the heat storage ball is easily adhered by high-viscosity sludge, the disturbance to the sludge drying process is small, and the heating efficiency is low. The surface of the heat storage ball is subjected to smoothing treatment, so that the heat storage ball can be quickly separated from dry sludge during screening, and the surface layer is free from sticking materials. The density of the heat storage ball is preferably 2t/m³More preferably 2 to 8t/m³. When the density of the heat storage ball is lower than 2t/m³In time, the disturbance to the sludge drying process is small, and the heating efficiency is low; when the density of the heat storage ball is higher than 8t/m³When the specific gravity is too large, not only can the power consumption be increased, but also the impact force is large, and the equipment abrasion is easily caused.

The addition amount of the heat storage balls is preferably 10-30% of the volume of wet sludge. When the adding proportion of the heat storage balls is less than 10% of the volume of the sludge, the drying efficiency is not obviously improved, and the disturbance of the heat storage balls in a viscous zone of a feeding section is poor, so that the phenomena of local sludge drying, caking, wall sticking and the like are still inevitable; when the addition ratio of the heat storage balls is higher than 30% by volume of the sludge, the drying productivity is lowered, and the economical efficiency is poor. In addition, the temperature of the heat storage balls in contact with the wet sludge is preferably 120 to 180 ℃.

The filling rate of the wet sludge and the heat storage balls in the rotary drum indirect drying device 4 is less than or equal to 30%, when the filling rate is greater than 30%, the filling rate in the drum is too high, so that the disturbance of the lifting plate and the heat storage balls on the sludge is poor, and the sludge layer is too thick, so that the heat exchange efficiency is reduced, the effect of internal and external cooperative heating dehydration is influenced, and the stable operation of the equipment is not facilitated.

The present invention will be described in detail below by way of examples.

Example 1

As shown in FIG. 1, wet sludge and heat storage balls (the addition amount of the heat storage balls is 10% of the volume of the wet sludge; the water content of the wet sludge is 85%; the heat storage balls are smooth-surfaced balls, have a diameter of 0.5cm and a density of 5t/m³) Respectively conveyed into a buffer bin 2 by a No. 1 conveying device 1 and a No. 2 conveying device 3, and then jointly fed into a rotary roller with the heating hearth temperature of 300 DEG CThe indirect drying device 4 (the filling rate of wet sludge and heat storage balls in the indirect drying device of the rotary drum is 20%) is used for carrying out internal and external cooperative drying dehydration, the dried material is screened by a screening device 5, the undersize is dried sludge and is directly sent into a dry sludge storage device 6, the oversize is heat storage balls and is conveyed into a waste heat recovery device 8 by a 3# conveying device 7 to be heated by the waste heat of flue gas; flue gas generated in the rotary drum indirect drying device 4 is conveyed to the waste heat recovery device 8 through the flue gas pipeline 9 to heat the heat storage balls, the temperature of the heated heat storage balls is raised to 160 ℃, and the heated heat storage balls are conveyed into the rotary drum indirect drying device 4 through the 2# conveying device 3 again to realize recycling. It was shown that the water content of the dried sludge fed into the dried sludge storage 6 was<3 percent. Drying efficiency is improved compared with indirect drying>15% and the energy consumption is reduced>25 percent, the sludge is basically not hardened and stuck to the wall in the whole drying process.

Example 2

As shown in FIG. 1, wet sludge and heat storage balls (the addition amount of the heat storage balls is 20% of the volume of the wet sludge; the water content of the wet sludge is 60%; the heat storage balls are smooth-surfaced balls having a diameter of 2cm and a density of 7.8t/m³) The sludge is conveyed into a buffer bin 2 through a No. 1 conveying device 1 and a No. 2 conveying device 3 respectively, and then the sludge and the sludge are jointly conveyed into a rotary drum indirect drying device 4 (the filling rate of wet sludge and heat storage balls in the rotary drum indirect drying device is 20%) for internal and external cooperative drying and dehydration, the dried material is screened through a screening device 5, the undersize is dry sludge and is directly conveyed into a dry sludge storage device 6, the oversize is heat storage balls and is conveyed into a waste heat recovery device 8 through a No. 3 conveying device 7 to be heated by the waste heat of the flue gas; flue gas generated in the rotary drum indirect drying device 4 is conveyed to a waste heat recovery device 8 through a flue gas pipeline 9 to heat the heat storage balls, the temperature of the heated heat storage balls is raised to 150 ℃, and the heated heat storage balls are conveyed into the rotary drum indirect drying device 4 through the 2# conveying device 3 again to realize recycling. It was shown that the water content of the dried sludge fed into the dried sludge storage 6 was<3 percent. Improved drying efficiency compared to indirect drying>15% of energy consumptionReduce>23 percent, the sludge is basically not hardened and stuck to the wall in the whole drying process.

Example 3

As shown in FIG. 1, wet sludge and heat storage balls (the addition amount of the heat storage balls is 30% of the volume of the wet sludge; the water content of the wet sludge is 40%; the heat storage balls are smooth-surfaced balls having a diameter of 1cm and a density of 3t/m³) The sludge is conveyed into a buffer bin 2 through a No. 1 conveying device 1 and a No. 2 conveying device 3 respectively, and then the sludge and the sludge are jointly conveyed into a rotary drum indirect drying device 4 (the filling rate of wet sludge and heat storage balls in the rotary drum indirect drying device is 10%) for internal and external cooperative drying and dehydration, the dried material is screened through a screening device 5, the undersize is dry sludge and is directly conveyed into a dry sludge storage device 6, the oversize is heat storage balls and is conveyed into a waste heat recovery device 8 through a No. 3 conveying device 7 to be heated by the waste heat of the flue gas; flue gas generated in the rotary drum indirect drying device 4 is conveyed to the waste heat recovery device 8 through the flue gas pipeline 9 to heat the heat storage balls, the temperature of the heated heat storage balls is raised to 130 ℃, and the heated heat storage balls are conveyed into the rotary drum indirect drying device 4 through the 2# conveying device 3 again to realize recycling.

The results show that the moisture content of the dried sludge fed into the dry sludge storage 6 is < 8%. Compared with the common indirect drying, the drying efficiency is improved by more than 15 percent, the energy consumption is reduced by more than 20 percent, and the sludge is basically not hardened and stuck to the wall in the whole drying process.

The above results show that the utility model, by mixing the water-containing sludge and the heat storage ball, jointly sends the water-containing sludge into the rotary indirect drying heating roller to crush and disturb the wet sludge, realizes high-efficiency drying of the sludge by means of internal and external cooperative heating, solves the problems of dust accumulation and sludge adhesion in the drying process, avoids the problems of easy hardening, easy wall adhesion, low drying efficiency and the like of direct drying of the sludge, and can improve the drying efficiency by more than 15 percent compared with the common indirect drying; flue gas generated by the rotary drum indirect drying device 4 is used for heating the heat storage ball body, waste heat is recycled, efficient utilization of energy is achieved, and compared with ordinary indirect drying, energy efficiency can be improved by more than 20%. To sum up, the utility model discloses the technology that corresponds is simple relatively, nimble, and device working costs is low, the practicality is strong, the processing scale is big, and drying efficiency is high, and energy resource consumption is low, has apparent social, economic benefits and environmental benefit.

Although embodiments of the present invention have been shown and described, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that changes, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art without departing from the principles and spirit of the present invention.

Claims (10)

1. The sludge drying and dewatering equipment is characterized by comprising a 1# conveying device (1), a buffer bin (2), a 2# conveying device (3), a rotary drum indirect drying device (4), a screening device (5), a dry sludge storage device (6), a 3# conveying device (7) and a waste heat recovery device (8); the No. 1 conveying device (1) and the No. 2 conveying device (3) are arranged at the top of the buffer bin (2) and are respectively used for conveying wet sludge and heat storage balls into the buffer bin (2); a mixture outlet at the bottom of the buffer bin (2) is communicated with a feeding port of the rotary drum indirect drying device (4), and a discharging port of the rotary drum indirect drying device (4) is communicated with a feeding port of the screening device (5); undersize products of the screening device (5) are introduced into a dry sludge storage device (6), and oversize products are conveyed into a waste heat recovery device (8) through a 3# conveying device (7); and materials in the waste heat recovery device (8) are conveyed back to the buffer bin (2) through the 2# conveying device (3).

2. The sludge drying and dewatering equipment according to claim 1, wherein the bottom of the surge bin (2) is provided with an inclined chute, and the mixture outlet of the surge bin (2) is positioned at the bottom end of the inclined chute.

3. The sludge drying and dewatering equipment according to claim 1, further comprising a flue gas and tail gas purification device (10), a flue gas fan (11) and a chimney (12), wherein a flue gas outlet of the waste heat recovery device (8) is communicated with a flue gas inlet of the flue gas and tail gas purification device (10), and the purified flue gas is pumped to the chimney (12) through the flue gas fan (11) and is discharged after reaching standards.

4. The sludge drying and dewatering equipment according to claim 1, wherein the rotary drum indirect drying device (4) comprises a rotary drum, a flue gas pipeline (9), a gas pipeline (18), a gas fan (19), a burner (20) and a hearth (21), the rotary drum is arranged inside the hearth (21), a top flue gas outlet of the hearth (21) is communicated with a flue gas inlet of the waste heat recovery device (8) through the flue gas pipeline (9), the burner (20) is arranged at the bottom of the hearth (21) and at the end of the gas pipeline (18), and the gas fan (19) is arranged on the gas pipeline (18); the gas is pumped to the end part of the gas pipeline (18) through the gas fan (19), is sprayed out through the burner (20) arranged at the end part of the gas pipeline (18), is burnt in the hearth (21) to be used as an indirect drying heat source, and the flue gas generated in the hearth (21) is sent into the waste heat recovery device (8) through the flue gas pipeline (9) to heat the heat storage ball.

5. The sludge drying and dewatering equipment according to claim 4, further comprising a steam pipe (13), a steam condensing device (14), an air pipeline (16) and an air fan (17), wherein a water sprayer is arranged at the top of the steam condensing device (14) and a water storage tank (15) is arranged at the bottom of the steam condensing device (14), a steam outlet of the rotary drum indirect drying device (4) is communicated with the steam condensing device (14) through the steam pipe (13), the steam condensing device (14) is used for condensing steam, the obtained condensed water is stored in the water storage tank (15) for recycling, and the obtained non-condensed gas is pumped to a hearth (21) through the air pipeline (16) under the action of the air fan (17) to be used for combustion supporting air.

6. The sludge drying and dewatering apparatus according to claim 1, wherein the sludge drying and dewatering device includes: the system comprises a 1# conveying device (1), a buffer bin (2), a 2# conveying device (3), a rotary drum indirect drying device (4), a screening device (5), a dry sludge storage device (6), a 3# conveying device (7), a waste heat recovery device (8), a flue gas and tail gas purification device (10), a flue gas fan (11), a chimney (12), a steam pipe (13), a steam condensing device (14), an air pipeline (16) and an air fan (17); the rotary drum indirect drying device (4) comprises a rotary drum, a flue gas pipeline (9), a gas pipeline (18), a gas fan (19), a burner (20) and a hearth (21); a water sprayer is arranged at the top of the steam condensing device (14), and a water storage tank (15) is arranged at the bottom of the steam condensing device;

the bottom of the buffer bin (2) is provided with an inclined chute which is communicated with a feeding port of the rotary drum indirect drying device (4); a steam outlet of the rotary drum indirect drying device (4) is communicated with a steam condensing device (14) through a steam pipe (13), the steam condensing device (14) is used for condensing steam, the obtained condensed water is stored in a water storage tank (15) for recycling, and the obtained non-condensed gas is pumped to a hearth (21) through an air pipeline (16) under the action of an air fan (17) for combustion-supporting air; the rotary drum is arranged in the hearth (21), the burner (20) is arranged at the bottom of the hearth (21) and at the end part of the gas pipeline (18), and the gas fan (19) is arranged on the gas pipeline (18); the tip of gas pipeline (18) is pumped to through gas fan (19) to the gas, through setting up combustor (20) blowout at gas pipeline (18) tip, burns as indirect dry heat source in furnace (21), the top exhanst gas outlet of furnace (21) passes through flue gas pipeline (9) and waste heat recovery device (8) flue gas entry intercommunication, the exhanst gas outlet of waste heat recovery device (8) and the flue gas entry intercommunication of flue gas tail gas purification device (10), and the flue gas after the purification is pumped to chimney (12) emission up to standard through flue gas fan (11).

7. The sludge drying and dewatering apparatus according to claim 6,

the No. 1 conveying device (1) is a single-shaft, double-shaft or shaftless screw conveyor or an embedded scraper conveyor;

the No. 2 conveying device (3) is a single-shaft, double-shaft or shaftless screw conveyor;

the heat-resistant temperature of the rotary drum indirect drying device (4) is not lower than 400 ℃, and the heating mode is indirect heating;

the screening device (5) is a vibrating screen or a rotary screen;

the 3# conveying device (7) is a large-inclination-angle belt conveyor, a bucket elevator or an embedded scraper conveyor;

the waste heat recovery device (8) is a shaft furnace for directly contacting and exchanging heat between the heat storage ball body and the flue gas;

the chimney (12) is a steel or concrete chimney;

the combustor (20) is a natural gas combustor, an oil gas combustor, a biomass pyrolysis gas combustor or a gas combustor.

8. The sludge drying and dewatering equipment as claimed in any one of claims 1 to 7, wherein the length-diameter ratio of the rotary drum indirect drying device (4) is (10-20): 1.

9. The sludge drying and dewatering equipment as claimed in claim 8, wherein the inner wall of the rotary drum is provided with the lifting blades, the lifting blades face the shaft center and are uniformly distributed along the circumference of the drum diameter at intervals of 30-60 degrees, and two adjacent lifting blades are distributed in a staggered manner; the three sections are arranged along the moving direction of the materials, the front part 1/3 of the roller is a first section, the middle part 1/3 of the roller is a second section, and the rear part 1/3 of the roller is a third section; the number ratio of the three material raising plates is 1:2: 1.

10. The sludge drying and dewatering equipment as claimed in claim 9, wherein the material raising plate is a cuboid, the length is 5-15 cm, and the length is: width: the height is (3-5) 1: 0.1.

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