JP3626717B2 - Granulation drying system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a granulation drying system that generates dry granular soil from sludge generated in a water treatment facility such as a water purification plant.
[0002]
[Prior art]
In water treatment facilities such as water purification plants, a large amount of sludge is generated during water treatment. As a method for effectively using such sludge, various methods for producing dry granular soil from the sludge have been proposed. The dry granular soil is useful as agricultural or horticultural soil, and the sludge recycling method is preferable from the viewpoint of resource recycling.
[0003]
However, the conventional sludge recycling method has not been sufficiently considered in terms of cost and the like.
That is, the dry granular soil is useful as agricultural or horticultural soil, but is not so expensive. Therefore, when producing dry granular soil from sludge, it is necessary to reduce the cost as much as possible, but conventional methods are not sufficiently considered in this regard.
[0004]
[Problems to be solved by the invention]
This invention is made | formed in view of the said problem, and it aims at providing the granulation drying system which can produce | generate dry granular soil from sludge at as low a cost as possible.
[0005]
[Means for Solving the Problems]
In order to achieve the object, the present invention is a granulation drying system for generating dry granular soil from raw material sludge, wherein the raw material sludge is dehydrated and the raw material sludge is made into a dehydrated cake, A kneader for kneading dewatered cake-like raw material sludge, a granulating part for granulating the raw material sludge supplied from the kneader, and heating the granular sludge that is communicated with the granulating part and supplied from the granulating part A drying unit having a drying unit, wherein the drying unit uses thermal energy generated in a generator as a heat source, and the generator has a gas engine using natural gas as fuel, and the drying unit A heating pipe that uses steam discharged from the gas engine as a heat source is inserted into the part, and a heating member that uses steam discharged from the gas engine as a heat source is provided outside the granulation part. Providing a characteristic granulation drying system To.
[0006]
Ri preferably yo, a purge device for supplying heated gas to said granulation section, further comprising, the purge device may be referred to with the steam discharged from the gas engine as a heat source of the heating gas.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of a granulation drying system according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic diagram of a granulation drying system 1 according to the present embodiment.
[0008]
The granulation drying system 1 can be effectively used in a water treatment facility where a large amount of sludge is generated, such as a water purification plant. In this Embodiment, the case where this granulation drying system is applied to a water purification plant is demonstrated.
[0009]
The granulation drying system 1 includes a dehydrator 10 for dewatering sludge generated in a water purification process, a kneader 20 for kneading sludge that has been made into a dehydrated cake by the dehydrator 10, and a kneader 20 for kneading. And a granulating dryer 30 for granulating and drying the dewatered sludge.
[0010]
Preferably, the granulation drying system 1 can further include a sludge heating tank 40 disposed on the upstream side of the dehydrator 10. By providing the sludge heating tank 40, the dewatering efficiency in the dehydrator 10 can be improved.
[0011]
More preferably, the granulation drying system 1 includes a coagulation sedimentation basin 51 for coagulating and precipitating sludge as a raw material from wastewater generated during water treatment in a water treatment plant, and a sedimentation sludge in the coagulation sedimentation basin 51 (for example, A sludge collecting pump 52 for transferring a sludge concentration 2-3%) and a concentration tank 53 for temporarily storing the sludge transferred by the mud collecting pump 52. The concentrated sludge (for example, sludge concentration 4.1 to 9.4%) can be transferred to the sludge warming tank 40 or the dehydrator 10 by the drawing pump 54 or the like.
[0012]
The dehydrator 10 removes excess moisture from the sludge and prevents the sludge from becoming too hard so that the sludge can be properly subjected to subsequent kneading and granulation (dehydrated cake). Be prepared for.
The dehydrator 10 may employ various methods, but preferably uses an electroosmotic filter press type dehydrator from the viewpoints of low pressing pressure and easy adjustment of the moisture content of sludge. Can do.
The dewatered cake sludge generated by the dehydrator 10 is preferably temporarily stored in the dewatered cake hopper 12 via the conveyor 11.
[0013]
The dehydrated cake sludge supplied to the kneader 20 directly from the dehydrator 10 or via the dehydrated cake hopper 12 has a moisture content of 45 to 70%, preferably 55 to 70%. Preferably, the water content is adjusted to 65 ± 5%.
Specifically, the water content of the dewatered cake sludge is adjusted by appropriately adjusting the water content by the dehydrator 10 or by naturally drying or adding water when the dewatered cake hopper 12 is provided. Adjust the rate.
Thus, the kneading process by the kneader 20 can be performed efficiently by adjusting the water content of the dewatered cake sludge supplied to the kneader 20.
[0014]
The kneader 20 is provided to make the water contained in the dewatered cake sludge uniform throughout the sludge and to soften the cake sludge to facilitate the subsequent granulation process.
[0015]
FIG. 2 shows a vertical side view of the kneader. FIG. 3 is a sectional view taken along line III-III in FIG.
As shown in FIGS. 2 and 3, the kneader in the present embodiment is of a biaxial type. Specifically, the kneader 20 includes first and second rotary shafts 21 and 22 that are rotationally driven around an axis, and the first and second rotary shafts 21 and 22 disposed substantially parallel to each other, The first and second rotary shafts 21 and 22 are accommodated, and a housing 23 provided with a sludge supply port 23a and a sludge discharge port 23b on the proximal end side and the distal end side, respectively.
[0016]
The first and second rotating shafts 21 and 22, respectively, are a main shaft 24, a feed screw 25 provided on the base end side of the main shaft 24 so as not to be relatively rotatable so as to face the sludge supply port 23a, A helical paddle group 26 provided on the main shaft 24 in a relatively non-rotatable manner at a position on the tip side of the feed screw 25, and under the mutual action, sludge is fed from the supply port 23a to the discharge port 23b. The sludge can be kneaded while being transferred.
[0017]
More preferably, the first and second rotary shafts 21 and 22 include a discharge screw 27 disposed on the main shaft 24 so as to face the discharge port 23b at a position on the tip side of the helical paddle group 26. Thus, the sludge can be efficiently discharged from the discharge port 23b.
In addition, the code | symbol 28 in FIG. 3 is the pushing roller arrange | positioned so that the said supply port 23a may face, and the sludge supplied from the dehydrator 10 or the dewatering cake hopper 12 is the said 1st and 2nd rotating shaft 21, It is provided for forcibly transporting towards 22.
[0018]
The granulator / dryer 30 is used to make the sludge having a uniform water content by the kneader 20 into a clay shape and to dry the sludge. When using the dry granular soil produced | generated with the system 1 which concerns on this Embodiment as soil for agriculture and horticulture, a particle size shall be 0.5 mm-5 mm, for example, and a moisture content is 30%-35%. Then, it is processed by the granulator / dryer 30.
[0019]
In FIG. 4, the partial vertical side view of the granulation dryer 30 in this Embodiment is shown.
As shown in FIG. 4, the granulator / dryer 30 is supplied with the sludge from the kneader, and is integrated with the granulator 31 for granulating the sludge, and the granulator 31. And a drying unit 32 for drying the granular sludge sent from the unit 31.
[0020]
The granulating part 31 is a hollow cylindrical granulating part housing 31a whose base end is closed and whose distal end is open, and the granulating part housing 31a is driven to rotate around an axis, A rotary shaft 31b disposed in the granule housing along the longitudinal direction of the grain housing 31a, a rotary blade 31c provided so as not to rotate relative to the rotary shaft 31b, and an axis about the rotary shaft 31b And a heating member 31e disposed on the outer peripheral surface of the granulation part housing 31a. Thus, by providing the heating member 31e on the outer peripheral surface of the granulated portion housing 31a, it is possible to effectively prevent sludge from adhering to the inner peripheral surface of the granulated portion housing 31a, and to make granulation easier. be able to.
[0021]
The drying part 32 has a hollow cylindrical drying part housing 32a whose base end part is connected to the distal end part of the granulation part housing 31a so as not to rotate relative to the axis, and extends along the longitudinal direction of the drying part housing 32a. And one or a plurality of heating pipes 32b disposed in the drying unit housing 32a.
Thus, the drying unit 32 is an indirect heating system via the heating pipe 32b, and the granular sludge is efficiently removed without destroying the granular sludge granulated by the granulation unit 31. Can be dried.
[0022]
A partition plate 33 for reducing the effective diameter of the communication path from the granulation unit housing 31a to the drying unit housing 32a is provided at a boundary portion between the granulation unit housing 31a and the drying unit housing 32a. Preferably, the position of the partition plate 33 is adjustable along the radial direction so that the sludge residence time in the granulation unit housing 31a can be adjusted.
4 denotes a motor that rotationally drives the granulating part housing 31a and the drying part housing 32a around the axis, and 35 denotes the relative movement around the axis of the granulating part housing 31a and the drying part housing 32a. It is a support member that is rotatably supported.
[0023]
In the granulation dryer having such a configuration, the sludge supplied through the hopper 36 provided as appropriate is converted into granular sludge having a desired particle diameter by the granulation unit 31, and the granular sludge is obtained by the drying unit 32. It can be dried without being damaged, and discharged from the outlet 37 as dry granular soil.
The particle size of the granular sludge includes the rotational drive direction and rotational speed of the granulation unit housing and the drying unit housing, the rotational drive direction and rotational speed of the rotary shaft of the granulation unit, and sludge retention in the granulation unit. It is adjusted by appropriately setting the radial position of the partition plate for adjusting the time.
[0024]
By the way, in the granulation process in the granulation part 31, the moisture content of sludge has a big influence on a particle size. That is, even if the moisture content of the sludge is adjusted at the time when it is supplied to the kneading machine 20, if unnecessary moisture adheres to the sludge in the granulation unit 31, the final dry granular soil particle size is within the desired range. It will deviate.
As described above, since the heating pipe 32b is inserted into the drying unit housing 32a and the heating member 31e is provided outside the granulation unit housing 31a, the drying unit housing 32a and the granulation unit housing 31a. The inside temperature is higher than the outside temperature. Such a temperature difference causes condensation on the inner peripheral surface of the drying unit housing 32a and / or the granulation unit housing 31a. When the condensed moisture adheres to the sludge in the granulating unit housing 31a and / or the drying unit housing 32a, the moisture content of the sludge varies and the particle size also varies.
[0025]
From this point of view, the present embodiment includes a purge device 60 that supplies a heated gas from the base end of the granulation unit housing 31a toward the tip of the drying unit housing 32a. It effectively prevents excess moisture from adhering to the sludge by blowing away moisture.
Specifically, the purge device 60 includes a blower 61, a pipe 62 having a base end portion communicated with the blower and a tip end portion communicated with a base end portion of the granulation unit housing 31a, And a heating unit 63 for heating the gas.
[0026]
The granulation drying system 1 according to the present embodiment is configured to use thermal energy generated in the generator 100 that generates part or all of the power of each facility in the water purification plant as a heat source in the drying unit 32. ing.
That is, the generator 100 is provided in a facility such as a water purification plant to which the granulation drying system 1 is applied, and the thermal energy generated in the generator 100 is effectively used.
[0027]
The generator 100, from the viewpoint of economy and environmental, adopt gas engine type for a natural gas as fuel. For example, the generator 100 can include two 500 KW gas engine generators. Specifically, in the granulation drying system 1 according to the present embodiment, as shown in FIGS. 1 and 4, steam generated in the generator 100 is used for heating the drying unit 32 via a pipe 110. It is introduced into the pipe 32b. In addition, the code | symbol 110a in FIG. 4 is the rotary joint which connects the said piping 110 and the said piping 32b for a heating, and the code | symbol 110b is a drain piping.
[0028]
In addition, the heating member 31e in the granulation section 31 also, configured to utilize the steam as a heat source. For example, the steam in the heating pipe 32b may be introduced into the heating member 31e (see FIG. 4). Further, the heating unit 63 in the purge device 60 is an indirect heating device such as a heat exchanger, and steam generated in the generator 100 is used as a heat source for the heating unit 63 and / or the steam is used as the heat source. It can also be used as a heat source for the heating tank 40.
[0029]
Thus, in the present embodiment, the steam generated in the generator 100 is used as a heat source for the drying unit 32, the granulating unit 31, the purge device 60, and / or the heating tank 40. Therefore, dry granular soil can be produced at as low a cost as possible.
[0030]
【The invention's effect】
As described above, according to the granulation drying system according to the present invention, the heat energy generated in the generator is used as the heat source of the drying unit, granulation unit, purge device and / or heating tank in the granulation dryer. Therefore, dry granular soil can be produced at as low a cost as possible.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of a granulation drying system according to an embodiment of the present invention.
2 is a longitudinal side view of a kneader in the granulation drying system shown in FIG. 1. FIG.
FIG. 3 is a cross-sectional view taken along line III-III in FIG.
4 is a partial longitudinal side view of a granulation dryer in the granulation drying system shown in FIG. 1. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Granulation drying system 10 Dehydrator 20 Kneading machine 30 Granulation dryer 31 Granulation part 31e Heating member 32 Drying part 32b Pipe for heating 40 Sludge heating tank 60 Purge apparatus 100 Generator

Claims (2)

A granulation drying system for generating dry granular soil from raw sludge, wherein the raw sludge is dehydrated to make the raw sludge into a dehydrated cake, and a kneader for kneading the dehydrated cake of raw sludge A granulating dryer having a granulating part for granulating the raw material sludge supplied from the kneader, and a drying part communicating with the granulating part and heating and drying the granular sludge supplied from the granulating part; The drying unit uses heat energy generated in a generator as a heat source , the generator has a gas engine using natural gas as fuel, and steam discharged from the gas engine is supplied to the drying unit. A granulation drying system , wherein a heating pipe serving as a heat source is inserted, and a heating member using steam discharged from the gas engine as a heat source is provided outside the granulation unit. A purge device for supplying heated gas to said granulation section, further comprising, the purge apparatus, granulation according to claim 1, characterized by using the steam discharged from the gas engine as a heat source for the heated gas Grain drying system.

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