JP2002224697A - Facility and method for treating sludge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To subject hydrous sludge to be thrown in to more efficient heating treatment such as evaporation and combustion in a sludge treating facility and a sludge treating method. SOLUTION: This sludge treating facility is provided with a kiln 1 for burning hydrous sludge G to be thrown in from the kiln bottom part side on the inside and a sludge throwing mechanism for throwing the hydrous sludge in the kiln 1 from the kiln bottom part side. The kiln bottom part is connected to a housing 2 the bottom face 2a of which is formed into a slope inclined downward toward the kiln side. The sludge throwing mechanism is provided with a sludge introducing pipe 10 for sending hydrous sludge forcibly and a sludge throwing port 11 connected to the tip of the pipe 10 at the position parted upward from the face 2a for dropping the hydrous sludge toward the face 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sludge treatment facility and a sludge treatment method in which hydrated sludge is put into a kiln and incinerated.

[0002]

2. Description of the Related Art In recent years, as a method for treating sludge such as sewage sludge discharged from a sewage treatment plant, a technology for converting cement raw material by directly blowing a sewage sludge dewatered cake into a cement firing furnace (direct combustion method) has been proposed and put into practical use. Have been. This technology uses sewage dewatered sludge treated to about 80% moisture (hereinafter, referred to as
Hydrated sludge) by truck, etc., and directly into the rotary kiln, a cement sintering furnace, by a pressure pump.
Heating at an ultra-high temperature causes water and combustibles to evaporate and burn, and sinter the inorganic ash as clinker, an intermediate cement product.

[0003] As described above, according to the above-mentioned treatment technique, the ash in the hydrous sludge is converted into a cement raw material by being replaced as a part of the clay raw material, and no secondary waste is produced.
This is an excellent treatment method for protecting the environment.

Conventionally, in order to put wet sludge into a rotary kiln, for example, as described in Japanese Patent Application Laid-Open No. 8-276199, a sludge inlet is provided at the bottom of the kiln bottom of the kiln and the sludge inlet is provided. From the sewage sludge was introduced.

[0005]

However, the above-mentioned conventional sludge treatment techniques have the following problems. That is, when pouring the hydrous sludge into the rotary kiln,
Since the hydrous sludge is pumped to the sludge inlet by the pump, the sludge is extruded from the sludge inlet into a certain mass and introduced into the kiln. For this reason, the hydrated sludge is heated for a while in a lump state immediately after being put into the kiln bottom part, and it takes time until the inside is sufficiently heated and evaporated.

[0006] The present invention has been made in view of the above-mentioned problems, and provides a sludge treatment facility and a sludge treatment method capable of more efficiently performing a heating treatment such as evaporation and combustion of a hydrated sludge to be charged. With the goal.

[0007]

The present invention has the following features to attain the object mentioned above. That is, the sludge treatment equipment of the present invention is a sludge treatment equipment having a kiln that injects and incinerates hydrous sludge from the kiln tail side and sludge that throws in the hydrous sludge from the kiln tail side of the kiln. The kiln is provided with a housing, the housing is connected to the kiln butt portion, and the housing has a slope whose bottom surface is inclined downward toward the kiln side.
A sludge introduction pipe for pressure-feeding the hydrous sludge, and a sludge input port for connecting the sludge introduction pipe at a tip thereof separated from the bottom surface of the housing upward and dropping the hydrous sludge toward the bottom surface. It is characterized by having.

The sludge treatment method of the present invention is a sludge treatment method in which hydrated sludge is introduced from the kiln tail side of the kiln and incinerated in the kiln, wherein the kiln has a housing connected to the kiln tail part. The housing has a bottom surface sloped downward toward the kiln side, and the wet sludge is pumped to a sludge inlet provided at a position separated upward from the bottom surface of the housing, and the sludge input is performed. The hydrated sludge is dropped from a mouth toward a bottom surface of the housing.

In these sludge treatment facilities and sludge treatment methods, wet sludge is pumped to a sludge inlet provided at a position spaced upward from the bottom surface of the housing, and the wet sludge is fed from the sludge inlet to the bottom surface of the housing. By dropping, the lump of hydrated sludge collides with the bottom and disperses, and the moisture etc. evaporates, and the remaining solids etc. slide down in a state of being shattered on the bottom which is the slope, and fall into the kiln body. be introduced.

Further, in the sludge treatment equipment of the present invention, it is preferable that the sludge inlet is disposed at least 3 m above a falling point of the hydrous sludge on the bottom surface of the housing. That is, in this sludge treatment facility, the sludge inlet is 3 m from the falling point of the hydrated sludge on the bottom surface of the housing.
By being disposed above, it is possible to obtain a falling speed at which the hydrated sludge in a lump state can be sufficiently dispersed at the time of bottom collision.

Further, in the sludge treatment equipment of the present invention, it is preferable that the sludge inlet is disposed at a position where the temperature is 800 ° C. or higher. That is, in this sludge treatment facility, since the sludge inlet is disposed at a temperature of 800 ° C. or higher, the water contained at the moment when the hydrous sludge is injected from the sludge inlet is subjected to steam explosion due to rapid heating. Cause, the hydrated sludge in the lump state is dispersed to some extent during the fall,
Dispersion can be ensured at the time of bottom collision.

Further, the sludge treatment equipment of the present invention employs a technology in which the kiln is a dry kiln for producing a cement clinker by firing a cement raw material. That is,
In this sludge treatment facility, since the kiln is a dry kiln that produces cement clinker by firing cement raw materials, hydrated sludge is converted into cement raw material by sintering it into clinker, an intermediate cement product, and hydrous sludge is effectively used. It is possible to decompose and reduce NOx contained in the exhaust gas at the time of calcination of the cement raw material by the ammonia component in the hydrous sludge.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a sludge treatment facility and a sludge treatment method according to the present invention will be described below with reference to FIGS.

As shown in FIG. 1 and FIG. 2, the sludge treatment equipment of this embodiment sinters cement raw material C0 in a dry rotary kiln 1 to sinter cement clinker C1,
It is a cement sintering facility to be manufactured and has a water content of 80%
The sewage sludge G, which is a sewage dewatered sludge, is introduced into the dry rotary kiln 1 from the kiln bottom 4a side and incinerated. In addition, although the hydrous sludge G supplied in this embodiment has not been subjected to pretreatment such as addition of additives, it may be subjected to such treatment.

A preheater 3 for preheating a cement raw material C0 that is pulverized by a raw material mill (not shown) and fed from a chute S is connected to the kiln bottom 4a of the dry rotary kiln 1 through the housing 2 to the sludge treatment equipment. It is configured such that the cement raw material C0 is charged into the kiln butt 4a via the preheater 3 and the housing 2. The preheater 3 is mainly composed of a plurality of cyclones 3a vertically arranged in a row and a duct 3b connecting the cyclones 3a so as to raise exhaust gas from the dry rotary kiln 1. Reference numeral F denotes an induction fan, which raises exhaust gas from the dry rotary kiln 1 through each cyclone 3a and each duct 3b and discharges the exhaust gas to the outside.

The dry rotary kiln 1 has a cylindrical kiln shell 4 which is connected to a housing 2 and has a kiln bottom 4a, which is inclined slightly downward and is driven to rotate in the circumferential direction, and a heavy oil provided on the downstream side of the kiln shell 4. A burner 5 that uses coal or pulverized coal as a fuel, and a clinker cooler 6 that is provided below the downstream portion of the kiln shell 4 and cools the manufactured cement clinker C1.

The sludge treatment facility is provided with a sludge feeding mechanism 7 for feeding wet sludge G from the kiln bottom 4a of the dry rotary kiln 1. The housing 2 has a bottom surface 2a that is inclined downward toward the dry rotary kiln 1 side. The sludge introduction mechanism 7 includes a sludge hopper 8 that stores the hydrated sludge G transported by a truck or the like, a sludge introduction pipe 10 that is connected to the sludge hopper 8 and that pumps the hydrated sludge G via a pressure pump 9. The sludge introduction pipe 10 has a sludge inlet 11 that is connected to a position spaced upward from the bottom surface 2a of the housing 2 and that allows the hydrated sludge G to drop toward the bottom surface 2a. That is, the sludge inlet 11 is connected to the preheater 3 and the kiln bottom 4.
It is provided on the inner wall of the housing 2 which is a connection portion with the a.

The sludge inlet 11 is arranged at a height h of at least 3 m above the falling point of the hydrated sludge G on the bottom surface 2a of the housing 2 and at a temperature of 800 ° C. or more. . The inner wall of the housing 2 is provided with a raw material inlet 12 through which the cement raw material C0 from the cyclone 3a of the preheater 3 is injected into the kiln bottom 4a via the housing 2.

Next, a method for treating sludge in the present embodiment will be described. Note that solid arrows in FIG. 1 indicate the directions in which the cement raw material C0 and the hydrated sludge G are transferred,
Dashed arrows indicate the gas flow direction.

First, the cement raw material C0 preheated from the preheater 3 is dropped into the dry rotary kiln 1 from the kiln butt 4a side through the housing 2 and fired by heating the burner 5 in the rotating dry rotary kiln 1. .
On the other hand, hydrated sludge G transported from a sewage treatment plant by a truck or the like and stored in a sludge hopper 8 is pumped from a sludge introduction pipe 10 to a sludge inlet 11 by a pressure pump 9.

Then, the fed hydrous sludge G is dropped from the sludge inlet 11 toward the bottom surface 2a of the housing 2. At this time, the water-containing sludge G in a lump collides with the bottom surface 2a to be dispersed and, at the same time, water and the like evaporate, as shown in FIG.
The remaining solids and the like slide down on the bottom surface 2a, which is a slope, in a state of being shattered, and are introduced into the kiln shell 4. In the housing 2, the fastest airflow is generated in the dry rotary kiln 1 from the kiln shell 4 to the preheater 3, so that the gas volatilized from the hydrous sludge G can flow efficiently to the preheater 3 side.

Further, since the sludge inlet 11 is disposed at a position 3 m or more above the falling point of the hydrated sludge G on the bottom surface 2a of the housing 2, a falling speed capable of sufficiently dispersing the lumpy hydrated sludge G is obtained. be able to. Furthermore, since the sludge inlet 11 is disposed at a position where the temperature is 800 ° C. or higher, the water contained at the moment when the hydrous sludge G is injected from the sludge inlet 11 causes a steam explosion due to rapid heating. The hydrated sludge G in a lump state is dispersed to some extent during the fall, and can be reliably dispersed at the time of collision with the bottom surface 2a.

The water-containing sludge G thus introduced into the kiln shell 4 is fired together with the cement raw material C0 by heating the burner 5, and becomes a cement clinker C1.
It is discharged after being cooled by the clinker cooler 6 downstream of the kiln shell 4. Thus, in this embodiment,
The hydrated sludge G is dispersed into pieces by the impact of the drop, and is charged into the kiln shell 4 and heated, so that the inside is sufficiently and efficiently heated and evaporated. In addition, since the hydrous sludge G is dispersed and charged and the ammonia component is also efficiently evaporated, NOx generated at the time of sintering the cement raw material is reduced by the denitration action by ammonia, and is more effectively reduced.

The technical scope of the present invention is not limited to the above embodiment, and various changes can be made without departing from the spirit of the present invention. For example, the sludge input port is not limited to one location, but may be provided at a plurality of locations with different heights, and the input port may be selectable according to the amount to be pressure-fed and dropped.

[0025]

According to the sludge treatment equipment and sludge treatment method of the present invention, hydrated sludge is pumped to a sludge inlet provided at a position spaced upward from the bottom of the housing, and the sludge is fed from the sludge inlet to the bottom of the housing. By dropping the hydrated sludge toward it, the lumped hydrated sludge collides with the bottom surface to disperse and evaporate the moisture, etc., and the solids etc. slide down on the bottom surface in a state of being broken into the kiln body. It is possible to introduce the water-containing sludge and to perform a heat treatment such as evaporation and combustion more efficiently.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing a sludge treatment facility in one embodiment of a sludge treatment facility and a sludge treatment method according to the present invention.

FIG. 2 is an enlarged cross-sectional view showing a kiln bottom in one embodiment of the sludge treatment facility and the sludge treatment method according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dry rotary kiln 2 Housing 2a Bottom of housing 3 Preheater 4 Kiln shell 4a Furnace bottom 7 Sludge feeding mechanism 10 Sludge introduction pipe 11 Sludge inlet 12 Raw material inlet C0 Cement raw material C1 Cement clinker G Wet sludge

Claims (5)

[Claims] Claims: 1. A sludge treatment facility having a kiln for injecting hydrous sludge from the kiln tail side and incinerating the sludge therein, comprising a sludge input mechanism for charging the hydrous sludge from the kiln tail side of the kiln, In the kiln, a housing is connected to the kiln bottom, and the housing has a bottom surface that is inclined downward toward the kiln side.The sludge input mechanism includes a sludge introduction pipe that pumps the hydrous sludge. A sludge inlet, which is provided so that a tip of the sludge introduction pipe is connected upward from the bottom surface of the housing and is provided to drop the hydrous sludge toward the bottom surface. Processing equipment. 2. The sludge treatment facility according to claim 1, wherein the sludge inlet is disposed at least 3 m above a falling point of the hydrous sludge on the bottom surface of the housing. . 3. The sludge treatment facility according to claim 1, wherein the sludge inlet is located at a temperature of 800 ° C. or higher. 4. The sludge treatment facility according to claim 1, wherein the kiln is a dry kiln that produces a cement clinker by firing a cement raw material. 5. A method for treating sludge, wherein hydrated sludge is introduced from the kiln tail side of a kiln and incinerated in the kiln, wherein the kiln has a housing connected to the kiln tail, and the housing has a bottom surface. The sludge is inclined downward toward the kiln side, and the hydrous sludge is pumped to a sludge inlet provided at a position spaced upward from the bottom surface of the housing, and is directed from the sludge inlet to the bottom surface of the housing. Sludge treatment method wherein the hydrated sludge is dropped.