CN111217511B

CN111217511B - Sludge drying device

Info

Publication number: CN111217511B
Application number: CN201911268430.0A
Authority: CN
Inventors: 刘晓辉; 刘依晨; 张越; 李叶橙
Original assignee: Huatian Engineering and Technology Corp MCC
Current assignee: Huatian Engineering and Technology Corp MCC
Priority date: 2019-12-11
Filing date: 2019-12-11
Publication date: 2022-02-01
Anticipated expiration: 2039-12-11
Also published as: CN111217511A

Abstract

The invention discloses a sludge drying device, and belongs to the field of sludge treatment equipment. The device comprises: a quicklime and water mixing tank for generating lime milk with fluidity and without heat release; the lime milk collecting tank is used for collecting lime milk after heat release; one end of the lime milk heat release pipe is connected with the quicklime and water mixing tank, the other end of the lime milk heat release pipe is connected with the lime milk collecting tank, and a lime milk delivery pump is arranged on the lime milk heat release pipe; and a sludge conveying pipe is sleeved outside the lime milk heat release pipe and used for heating and drying the sludge by using the lime milk heat release pipe. The invention takes the exothermic reaction of quicklime when meeting water and the exothermic reaction of iron-carbon micro-electrolysis as a drying heat source, and aims to solve the energy problem required by sludge drying. The invention realizes the purposes of saving energy consumption and reducing the emission of toxic gas to the maximum extent and realizes the effective and reasonable utilization of resources.

Description

Sludge drying device

Technical Field

The invention belongs to the field of sludge treatment equipment, and particularly relates to a sludge drying device.

Background

In order to reduce the sludge, the sludge is dried most commonly at present by adopting a drying method which has a good sludge drying effect, but consumes a large amount of energy and generates a large amount of harmful gases, so that the development of a sludge drying device which can save energy consumption and reduce the emission of the harmful gases is necessary.

Disclosure of Invention

In order to overcome the defects, the invention aims to provide a sludge drying device for drying industrial and municipal sludge.

In order to achieve the above object, the sludge drying device of the present invention comprises:

a quicklime and water mixing tank for generating lime milk with fluidity and without heat release;

the lime milk collecting tank is used for collecting lime milk after heat release;

one end of the lime milk heat release pipe is connected with the quicklime and water mixing tank, the other end of the lime milk heat release pipe is connected with the lime milk collecting tank, and a lime milk delivery pump is arranged on the lime milk heat release pipe;

and a sludge conveying pipe is sleeved outside the lime cream heat inlet pipe and is used for heating and drying the sludge by using a lime cream heat discharging pipe.

Furthermore, the sludge conveying pipe is formed by rolling a filter screen made of an air-permeable sludge blocking material; and an iron-carbon adsorption heat-insulation layer is arranged on the outer surface of the sludge conveying pipe.

Furthermore, two ends of the lime milk heat release pipe can be rotatably connected to a quicklime and water mixing tank and a lime milk collecting tank;

the rotation driving device is in transmission connection with the lime milk heat release pipe to drive the lime milk heat release pipe to rotate;

and a spiral steel belt is arranged on the outer surface of the lime milk heat release pipe corresponding to the sludge conveying pipe.

Furthermore, a dry sludge storage pool is arranged at the outlet of the sludge conveying pipe.

Furthermore, a sludge inlet of the sludge storage pool is positioned in the center of the dry sludge storage pool; the upper end of the dry sludge storage pool is provided with a gas collecting hood, and the gas collecting hood is connected with a vacuum pump through a gas collecting pipe.

Furthermore, a plurality of steam suction pipes are arranged on the sludge conveying pipe along the length direction; a mud blocking and steam passing net is arranged at the inlet of the steam suction pipe. Wherein the density of the steam suction pipe at the inlet of the sludge conveying pipe is greater than that at the outlet of the sludge conveying pipe or the density of the steam suction pipe at the sludge conveying pipe is arranged in a gradient manner from the inlet to the outlet.

Furthermore, the steam suction pipe is connected with a steam cooling system.

Further, a quicklime and water mixing tank is cylindrical and is made of heat-insulating materials, and a quicklime feeding port is formed above the quicklime and water mixing tank; a stirring device is arranged in the tank body; a water replenishing pipe is arranged at the bottom of the tank body; wherein the mass ratio of the quicklime to the water is 2: 1.

Further, a temperature sensor is arranged in the center of the quicklime and water mixing tank body; a return pipe is also arranged between the quicklime and water mixing tank and the lime milk collecting tank, and a return pump is arranged on the return pipe;

and the control device monitors the temperature in the quicklime and water mixing tank body in real time, and starts the reflux pump to reflux the lime milk in the lime milk collecting tank to the quicklime and water mixing tank when the monitored temperature of the lime milk in the quicklime and water mixing tank body exceeds a set temperature.

Further, a steel wire brush is arranged at the position, adjacent to the filter screen, of the edge of the spiral steel belt.

The invention takes the exothermic reaction of quicklime when meeting water and the exothermic reaction of iron-carbon micro-electrolysis as a drying heat source, and aims to solve the energy problem required by sludge drying. The sludge drying device has the advantages that the innermost layer is a lime cream flowing heat supply layer, the middle layer is wet sludge with the water content of 80-90%, the outermost layer is an iron-carbon adsorption heat insulation layer, the outer wall of the lime cream flowing pipe is spiral and can be driven to rotate by motors at two sides, and the functions of conveying sludge and preventing the sludge from being stuck and retained in the middle layer are achieved; the middle layer and the outermost layer are separated by a filter screen, and gas is allowed to pass through. The device furthest realizes saving energy consumption and reducing the emission of toxic gas, and realizes the effective and reasonable utilization of resources. The lime milk after heat release can still be used for industrial production after being processed, the used iron-carbon mixture can be used as a steelmaking raw material, and the dried sludge can be recycled as a fuel. The sludge drying equipment can be built in steel plants and plants consuming slaked lime and iron carbon, and can realize sustainable development while realizing sludge drying reduction.

Drawings

FIG. 1 is a flow chart of a sludge drying device

FIG. 2 is a sectional view taken along line a-a

The system comprises a quicklime and water mixing tank 1, a lime cream delivery pump 2, a sludge drying reactor 3, a lime cream heat-release pipe 4, an intermediate wet sludge layer 5, an external adsorption heat-preservation layer 6, a spiral steel belt 7, a sludge outlet 8, a dry sludge storage tank 9, a gas collecting hood 10, a lime cream collecting tank 11, a reflux pump 12, a motor 13, a sludge inlet pipe 14, a quicklime adding port 15, a stirring device 16, a water replenishing pipe 17, a steam suction pipe 18, a steam suction dry pipe 19, a filter screen 20, a steam-suction pipe 18, a steam-suction dry pipe 19, a steam-suction dry pipe and a steam-suction pipe

Detailed Description

The invention will be further explained with reference to the drawings

As shown in fig. 1 and 2, the sludge drying apparatus of the present invention includes: quick lime and water blending tank 1, sludge drying reactor 3, lime cream collecting tank 11, steam collection cooling system and exhaust-gas treatment system device constitute, quick lime and water blending tank 1 is the cylinder form and is made by the heat-insulating material, is equipped with agitating unit 16 in the jar, can make quick lime and water flash mixed generate the lime cream of mobile form, quick lime and water mass ratio are 1.5:1-3: 1; typically 2: 1; the method can ensure that the quicklime and the water completely react, and ensures that the lime milk has certain fluidity and the temperature of the lime milk is not reduced because of excessive addition of the water in consideration of water loss caused by water vapor evaporation. When adding, water is added from the bottom of the tank through a water supplementing pipe 17, and the quicklime is ground into powder and then spills from a quicklime adding port 15 on the top of the tank. The lime is sprinkled into the water to prevent sudden pressure increase in the pipe caused by water bumping evaporation, and also can reduce heat loss, the lime milk should not exceed 2/3 of the volume of the tank body, so that the tank top is left with enough space, and the ventilation pipe is arranged on the tank top to prevent the tank body from danger caused by thermal expansion.

The formed lime milk is conveyed into a lime milk heat release pipe 4 at the innermost layer of a sludge drying reactor 3 through a conveying pump to release heat, a lime milk conveying pump 2 is a variable frequency pump and can adjust the residence time of wet sludge in the drying reactor according to the moisture content of the wet sludge, the lime milk heat release pipe 4 has high heat conductivity, the heat release pipe can be driven by a motor 13 to rotate, the part of the heat release pipe connected with a tank body needs to be treated to prevent the lime milk from seeping out, the rotating speed can be adjusted according to the amount of the treated wet sludge, the wet sludge with the moisture content of 80% -90% enters an intermediate wet sludge layer 5 through a sludge inlet pipe 14, the outer wall of the lime milk heat release pipe 4 is connected with a spiral steel belt 7 for conveying the wet sludge, the diameter of the spiral steel belt 7 is as large as possible, the interval between the edge of the steel belt and a filter screen is as close as possible, and the optimal thread pitch can be determined through a sludge drying test. The pitch of the spiral steel belt is also a key parameter influencing the conveying of the dry sludge, and the optimal pitch can be determined through a sludge drying test.

And a sludge conveying pipe 20 is sleeved outside the lime cream heat inlet pipe and used for heating and drying the sludge by using the lime cream heat discharging pipe. The sludge conveying pipe is formed by rolling a filter screen made of air-permeable sludge blocking materials; an iron-carbon adsorption heat-insulation layer is arranged on the outer surface of the sludge conveying pipe; the iron-carbon adsorption heat-insulation layer can be sprayed on the outer surface of the filter screen 20, and an iron-carbon adsorption heat-insulation material can also be coated outside the sludge conveying pipe.

The middle sludge layer 5 and the external adsorption heat preservation layer 6 are separated by a layer of filter screen 20, the filter screen has good wear resistance, solid particles are not allowed to permeate, water vapor evaporated from wet sludge can only permeate, a steel wire brush is arranged at the edge of the spiral steel belt 7 and adjacent to the filter screen, wet sludge adhered to the inner wall of the filter screen can be cleaned in the rotating process, and the wet sludge is prevented from blocking filter screen holes to influence the air permeability.

The heat permeates the lime cream and releases the heat pipe transmission to wet mud, the steam evaporation in the wet mud is sucked through the absorption heat preservation 6 by the vacuum pump, in order to have better suction effect to the steam in the wet mud layer, set up intensive steam absorption branch pipe 18 near wet mud import department, set up sparser steam absorption branch pipe 18 keeping away from wet mud import department, steam absorption pipe carries waste gas and breathes in dry pipe 19, it is adsorbed by activated carbon to be sucked the part foul smell in the waste gas that adsorbs the heat preservation, reduce the foul smell and reveal the influence to staff's health, suction effect enables wet mud layer and remains the negative pressure state all the time, the saturated vapor pressure of steam has been reduced, promote the evaporation of wet mud normal water, be favorable to the transport of the steam that evaporates simultaneously. And then, the waste gas enters a cooling device, water vapor in the waste gas flows back to a waste water treatment system through cooling, and the residual waste gas enters a waste gas treatment system for further treatment and standard emission.

The iron-carbon combination generates micro-electrolysis reaction when meeting water vapor to release heat, so that the temperature change gradient between the inner lime cream heat release pipe and the external environment can be reduced, the excessive loss of heat of the inner lime cream heat release pipe can be reduced, the temperature of the middle wet sludge layer 5 is kept, and the sludge drying efficiency is improved.

The lime milk and the sludge are conveyed into a lime milk collecting tank 11 after heat exchange to be used as industrial production raw materials, if the lime milk still has residual heat which is not fully utilized, the lime milk can flow back to a quicklime and water mixing tank 1 through a return pump 12 to enter a sludge drying system again, and the return ratio of the lime milk return pump 12 can be determined through tests according to the actual operation condition of the device. The dried organic sludge is conveyed by a spiral conveyer belt 7 and passes through a sludge outlet 8 to a dry sludge storage tank 9 to be reused as fuel, a gas collecting hood 10 is arranged at the top of the dry sludge storage tank 9, the gas collecting hood 10 is connected with a gas collecting pipe, waste gas in the dry sludge storage tank 9 is sucked into a waste gas treatment device by a vacuum pump, the sludge outlet 8 is generally arranged in the middle of the dry sludge storage tank 9, and the gas collecting hood 10 is generally arranged around the dry sludge storage tank 9 and keeps a certain distance to ensure that the dry sludge falling is not influenced when the waste gas is sucked.

Claims

1. A sludge drying device is characterized in that: the device comprises:

a sludge conveying pipe is sleeved outside the lime milk heat release pipe and used for heating and drying sludge by using the lime milk heat release pipe; the sludge conveying pipe is formed by rolling a filter screen made of an air-permeable sludge blocking material; an iron-carbon adsorption heat-insulation layer is arranged on the outer surface of the sludge conveying pipe;

two ends of the lime cream heat release pipe can be rotatably connected to a quicklime and water mixing tank and a lime cream collecting tank;

2. The sludge drying apparatus of claim 1, wherein: and a dry sludge storage pool is arranged at the outlet of the sludge conveying pipe.

3. The sludge drying apparatus of claim 2, wherein: the sludge inlet of the sludge storage pool is positioned in the center of the dry sludge storage pool; the upper end of the dry sludge storage pool is provided with a gas collecting hood, and the gas collecting hood is connected with a vacuum pump through a gas collecting pipe.

4. The sludge drying apparatus of claim 1, wherein: a plurality of steam suction pipes are arranged on the sludge conveying pipe along the length direction; a mud blocking and steam passing net is arranged at the inlet of the steam suction pipe; wherein the density of the steam suction pipe at the inlet of the sludge conveying pipe is greater than that at the outlet of the sludge conveying pipe or the density of the steam suction pipe at the sludge conveying pipe is arranged in a gradient manner from the inlet to the outlet.

5. The sludge drying apparatus of claim 4, wherein: the steam suction pipe is connected with a steam cooling system.

6. The sludge drying apparatus of claim 1, wherein: the quicklime and water mixing tank is cylindrical and is made of heat-insulating materials, and a quicklime feeding port is formed above the quicklime and water mixing tank; a stirring device is arranged in the tank body; a water replenishing pipe is arranged at the bottom of the tank body; wherein the mass ratio of the quicklime to the water is 1.5:1-3: 1.

7. The sludge drying apparatus of claim 1, wherein: a temperature sensor is arranged in the center of the quicklime and water mixing tank body; a return pipe is also arranged between the quicklime and water mixing tank and the lime milk collecting tank, and a return pump is arranged on the return pipe;

8. The sludge drying apparatus of claim 1, wherein: and a steel wire brush is arranged at the position of the edge of the spiral steel belt adjacent to the filter screen.