JP3611173B2 - Sludge introduction pipe piping structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sludge inlet pipe structure, in particular, sewage that has not been subjected to pretreatment such as drying or addition of additives between the lower part of the preheater and the kiln bottom of a dry cement kiln for cement raw material firing. The present invention relates to a piping structure of a sludge introduction pipe for introducing and incinerating hydrous sludge such as sludge.
[0002]
[Prior art]
Sewage sludge discharged from sewage treatment plants has been used as fertilizer since ancient times, but the reason is that heavy metals are contained in sludge and that the amount of treatment is small when used as fertilizer. In recent years, land reclamation and ocean dumping have become mainstream.
However, sludge discharge from sewage treatment plants has been increasing in recent years, mainly in the Tokyo metropolitan area, and due to the lack of treatment plants for land reclamation and disposal at sea, as well as restrictions on preventing environmental pollution, At present, sludge treatment has shifted to incineration. Several types of sludge incineration facilities have already been proposed.
[0003]
However, in a conventional sludge incinerator using an incinerator, it is necessary to dry the sludge prior to incineration. In addition, the deodorized dry exhaust gas must be deodorized. Thereby, there existed a problem that drying cost, deodorizing cost, and incineration cost increased, and the processing cost as a whole became high.
A method using quick lime for drying sludge has also been proposed. In this method, quick lime is reacted with moisture contained in sludge to produce slaked lime, the residual moisture is evaporated by the reaction heat at that time, and the sludge is utilized as a dry material that can be pneumatically fed as a cement raw material. However, even this method has a problem that quick lime must be added during sludge drying.
[0004]
Therefore, as a prior art for solving such a problem, there is known a “sludge treatment method” disclosed in Japanese Patent Application Laid-Open No. 8-276199, which was previously filed by the applicant of the present patent application.
This is a sludge treatment technique in which water-containing sludge in a sludge tank is directly introduced into a kiln bottom or a preheater of a dry cement kiln (hereinafter sometimes referred to as dry kiln or simply kiln) and incinerated. According to this technology, normal production of cement clinker is carried out by pouring water-containing sludge directly into an existing dry cement kiln from a sludge introduction pipe without using a pretreatment such as drying or adding additives. At the same time, the water-containing sludge can be efficiently incinerated.
[0005]
[Problems to be solved by the invention]
By the way, in the dry-type cement kiln, since the refractory stretched on the inner peripheral surface of the kiln shell is damaged by heat or impact during the firing of the cement clinker, the refractory is periodically replaced.
During this operation, the operation of the dry cement kiln is temporarily stopped, and the temperature inside the kiln is lowered to a predetermined temperature, and then the operator enters the dry kiln and replaces the refractory.
[0006]
At this time, since the sludge introduction pipe is connected to the kiln bottom of the dry cement kiln and the preheater as described above, toxic gases such as hydrogen sulfide and methane gas volatilized from the surface of the hydrous sludge exposed from the pipe end. May flow into the kiln and harm the health of workers during work. Moreover, if a large amount of methane gas or the like is accumulated in the kiln, a gas explosion may occur in the kiln due to, for example, sparks generated by static electricity during work.
Therefore, usually, before the refractory is replaced, the sludge introduction pipe is washed with water while operating the dry cement kiln.
[0007]
That is, during the firing of the cement clinker, the supply of the water-containing sludge from the sludge tank to the sludge introduction pipe is first stopped, and then the cleaning water is pumped into the pipe from the cleaning water supply system. As a result, the back pressure by the washing water acts, and the water-containing sludge remaining in the sludge introduction pipe is sequentially washed from the upstream side in the sludge introduction pipe while pushing out the sludge introduction pipe into the pre-heater or kiln. . The water-containing sludge accumulated in the pipe is thrown into the dry kiln and then incinerated with the calcining heat of the cement raw material.
However, if the water-containing sludge in the sludge introduction pipe is entirely pushed out from the pipe end, a large amount of water for washing flows into the dry cement kiln. This is because the pipe of the sludge introduction pipe substantially matches the height of the pipe end on the kiln side with the height of a relatively long horizontal portion on the upstream side of the pipe end. Therefore, when this large amount of washing water flows, the firing temperature of the cement raw material in the dry kiln is lowered at once, and the refractory stretched in the kiln is damaged by a large temperature difference, or the cement manufactured intermediately There was a problem that the quality of the clinker deteriorated.
[0008]
OBJECT OF THE INVENTION
This invention can prevent the dry cement kiln from being damaged and the quality of the cement clinker from being deteriorated due to a rapid decrease in the temperature inside the kiln caused by the washing water flowing in a large amount from the pipe end when the sludge introduction pipe is washed. The purpose is to provide a piping structure of the sludge introduction pipe.
[0009]
[Means for Solving the Problems]
According to the first aspect of the present invention, one end of the preheater for calcining cement raw material is connected to the kiln bottom of the dry cement kiln for calcining cement raw material, and water-containing sludge is introduced into these. The sludge introduction pipe has a piping structure, and by providing an upward curved portion bent upward near one end of the sludge introduction pipe, cleaning water is pumped into the sludge introduction pipe for cleaning in the pipe. When water-containing sludge remaining in the pipe is pushed out from the pipe end on one end side of the sludge introduction pipe due to the action of back pressure by water, the wash water in the pipe flows out from the pipe end of the sludge introduction pipe all at once. It is a piping structure of the sludge introduction pipe which prevents it.
[0010]
Examples of the water-containing sludge here include sewage sludge, activated sludge, and sludge.
Hydrous sludge may be supplied directly from a sludge treatment facility via a pipeline, etc., or transported by a truck equipped with a sealed tank, once put into the sludge tank, and then supplied from this sludge tank. .
Although there is no restriction | limiting in particular in the addition amount of the water-containing sludge to a dry kiln, Usually, it determines suitably by various process conditions, such as the quality of a cement raw material, the usage-amount, and a calcination temperature. However, an amount that allows the water-containing sludge to be introduced into an existing dry kiln without particularly changing the operating conditions is preferable.
For example, when a dry kiln having a cement clinker production amount of 90 to 100 t / h is used, the amount of water-containing sludge added is 9 to 10.0 t / h, and 0 to 1/10 based on the weight of the cement clinker to be produced. It is preferable to add water-containing sludge to a certain extent. This is because if the amount of hydrous sludge added to the cement raw material exceeds 10.0 t / h, firing in the kiln becomes unstable due to moisture from the sludge, and the risk of adversely affecting the quality of the cement clinker increases.
[0011]
In addition, the space from the lower part of the preheater for cement raw material calcining to the bottom of the dry cement kiln for firing cement raw material (hereinafter sometimes referred to as the kiln bottom) is the lower part of the preheater. Not only the area and the kiln bottom area of the dry kiln, but a connecting part of both may be used. In addition, you may introduce | transduce a hydrous sludge into both the lower area | region of a pre-heater, and the kiln bottom area of a dry kiln.
The temperature of the introduction part of the hydrous sludge on the kiln kiln bottom side is 800 to 1000 ° C, preferably around 900 ° C. If it is less than 800 degreeC, combustion of a water-containing sludge tends to become inadequate, and when it exceeds 1000 degreeC, the malfunction that the operation of a furnace will be produced arises.
[0012]
Various slurry pumps can be used for pumping the hydrous sludge to the kiln kiln bottom side. Moreover, various normal pumps can be employed for pumping the washing water to the kiln kiln bottom side. The cleaning water pumped by these various pumps remains in the sludge introduction pipe by the length of the upstream side of the upper curved portion of the sludge introduction pipe after the in-pipe cleaning member of the sludge introduction pipe described later is discharged to the dry kiln. However, this remaining wash water is recovered by reversing the pumping direction of the wash water by the pump. Thereby, the operation of the dry kiln is stabilized.
[0013]
The upper curved portion of the sludge introduction pipe here is provided in the vicinity of one end of the pipe and is bent upward in one or two steps, or is U-shaped, V-shaped or It may be bent in a W shape or the like, or may be further bent in an inclined shape. Note that the upper curved portion includes a rising portion and a falling portion other than the horizontal or bent apex portion. If necessary, a lower curved portion that bends downward may be provided upstream and / or downstream from the formation position of the upper curved portion of the sludge introduction pipe. In this case, it may be an inverted U shape, an inverted V shape, a W shape, or the like.
When cleaning the sludge introduction pipe, it is preferable to use a pipe cleaning member that is inserted into the pipe and scrapes off the water-containing sludge that has adhered to the inner peripheral surface of the sludge introduction pipe.
The in-pipe cleaning member referred to here is, for example, a block made of a cloth made of a woven fabric, a non-woven fabric, and a knitted fabric, in addition to a sponge or flexible non-foamed plastic. In addition, if rubber is coated on at least one end surface of the sponge, it is possible to receive the action of the back pressure by the washing water without leaking, so that the in-pipe cleaning member can move in the pipe at a smooth speed.
[0014]
In addition, the direction where the sludge introduction pipe end arrival detection device which detects that the in-pipe cleaning member reached the one end part of the sludge introduction pipe is attached to one end of the sludge introduction pipe. The sludge introduction tube end arrival detection device here is a mechanical or electrical detection device designed so that the sensor function does not work when the hydrous sludge contacts, but only when the in-pipe cleaning member contacts. It is.
[0015]
The temperature in the dry cement kiln at the time of temperature rise after stopping the action of the back pressure by the washing water is preferably 800 to 1000 ° C. These matters can also be said in claims 2 to 4.
[0016]
The invention according to claim 2 is the piping structure of the sludge introduction pipe according to claim 1, wherein the upper curved portion is bent upward in a stepped manner by one step from the normal height of the sludge introduction pipe. The bending height of the upper curved portion is arbitrary. The normal height of the above sludge introduction pipe is the height of the horizontal part that occupies most of the kiln kiln bottom side of this pipe among the sludge introduction pipes that are laid from the sludge supply source to the kiln kiln bottom side and pump the sludge. Say.
[0017]
In the invention according to claim 3, in the case where the normal height of the sludge introduction pipe is higher than the pipe end height on one end side of the sludge introduction pipe, the upper curved portion once becomes the normal height of the sludge introduction pipe. 2. The sludge introduction pipe piping structure according to claim 1, wherein the sludge introduction pipe is lowered to the height of one end of the sludge introduction pipe after being bent upward by one step.
[0018]
Invention of Claim 4 is the sludge introduction | transduction of any one of Claims 1-3 in which the said upper curved part was provided within 50 cm from the pipe end of the one end side of the said sludge introduction pipe | tube. It is the piping structure of a pipe.
By forming the upper curved portion of the sludge introduction pipe within 50 cm from the pipe end on one end side of the sludge introduction pipe, when cleaning the pipe using the pipe cleaning member, It can be stopped once at the pipe end on one end side of the sludge introduction pipe. In addition, when the in-pipe cleaning member is discharged into the dry kiln, the amount of water flowing into the dry kiln together with the in-pipe cleaning member can be relatively reduced.
[0019]
[Action]
According to the invention described in claims 1 to 4, when cleaning water is pumped into the pipe during cleaning of the sludge introduction pipe, the hydrous sludge remaining in the pipe is caused by the action of back pressure by the cleaning water. Extruded from one end of the tube. The water-containing sludge pushed out from the end of the sludge introduction pipe is incinerated by the burning heat of the cement raw material generated in the dry cement kiln during normal operation.
When the sewage sludge is pushed out from the sludge introduction pipe, the washing water having a higher fluidity than the sewage sludge, which has applied back pressure to the sewage sludge, tries to flow into the kiln kiln bottom side at once. However, since an upper curved portion higher than the normal height is provided near one end of the sludge introduction pipe, the wash water is prevented from flowing out at a stroke due to the height difference. This washing water is collected from the lowest part of the pumping pipe to prevent inflow into the preheater and to stabilize the cement kiln.
[0020]
In particular, in the invention described in claim 2, since the upper curved portion has a shape that is relatively easy to shape, bent upward in a stepped manner by one step from the normal height of the sludge introduction pipe. When manufacturing the sludge introduction pipe, it is possible to relatively easily provide the upper curved portion near one end of the sludge introduction pipe.
[0021]
Further, in the invention according to claim 3, the shape of the upper curved portion is once bent upward in a step shape from the normal height of the sludge introduction pipe, and connected to the kiln kiln bottom side from there. Since it descends to the height, even if the end of the sludge introduction pipe connected to the kiln kiln bottom side is a pipe path located at a position lower than the normal height of this pipe, the effect of claim 1 is not hindered. Is obtained.
[0022]
Furthermore, in the invention according to claim 4, since the upper curved part is provided within 50 cm from the pipe end on one end side of the sludge introduction pipe, the upper curved part is formed at the time of manufacturing the sludge introduction pipe. Is relatively easy, and when water-containing sludge is pushed out from the sludge introduction pipe, the amount of cleaning water that slightly flows to the kiln kiln bottom side can be reduced.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the drawings. First, the first embodiment of the piping structure of the sludge introduction pipe of the present invention will be described.
FIG. 1 is a cross-sectional view schematically showing a cement firing facility to which a sludge introduction pipe piping structure according to a first embodiment of the present invention is applied. FIG. 2 is an enlarged cross-sectional view showing the main part of the sludge introduction pipe.
1 and 2, reference numeral 10 denotes a sludge introduction tube end arrival detection device (hereinafter sometimes simply referred to as a tube end arrival detection device) of a pipe cleaning member. An in-pipe cleaning member 20 for cleaning the inside of the sludge introduction pipe 16 whose one end is connected from the lower part of the preheater 11 to the kiln bottom part 12a of the dry cement kiln 12 for firing the cement raw material (kiln kiln bottom side), It is an apparatus that detects that the end of the sludge introduction pipe 16 has been reached.
[0024]
The sludge introduction pipe 16 is a pipe that introduces hydrated sludge a such as sewage sludge that has not been subjected to pretreatment such as drying and additive addition to the bottom of the kiln kiln. Further, in the vicinity of one end of the sludge introduction pipe 16, the sludge introduction pipe 16 is bent upward by one step (height difference of 200 mm or more (pipe diameter or more)) from the normal height, and the length L is 50 cm. An upper curved portion 16x is provided. Further, in the middle of the sludge introduction pipe 16, a three-way valve for switching this pipe line to the supply side of the hydrated sludge a from the sludge introduction apparatus 21 or the supply side of the wash water b from the wash water supply apparatus 22. 23 and the insertion opening 24 of the in-pipe cleaning member 20 are connected.
[0025]
The cement firing facility is an facility for intermediately producing a cement clinker by firing a cement raw material calcined in the preheater 11 in a dry cement kiln 12. In addition, the dry-type cement kiln 12 used here shall produce a cement clinker at 90-100 t / h.
The preheater 11 preheats the cement raw material pulverized by a raw material mill (not shown) to a predetermined temperature so that it can be easily fired by the downstream dry cement kiln 12. The pre-heater 11 is provided with a large number of cyclones mounted on a several-storey steel frame. Further, normally, a gas exhaust system that has a fan and guides the gas generated at the time of calcination to a gas processing facility (not shown) is connected to the uppermost cyclone.
[0026]
The dry cement kiln 11 has a horizontal cylindrical kiln shell slightly inclined downward toward the downstream side. A refractory material is stretched on the inner peripheral surface of the kiln shell.
While rotating the kiln shell in the circumferential direction, the cement raw material from the preheater 11 is fired by heating with a burner using heavy oil or fine coal as a fuel, and a cement clinker is intermediately manufactured. Thereafter, the cement clinker is cooled by a clinker cooler connected to the downstream portion of the dry cement kiln 12 and sent to the finishing process.
[0027]
The sludge introduction device 21 passes the sludge introduction pipe 16 between the lower part of the preheater 11 and the kiln bottom part 12a of the dry cement kiln 12 in a slurry state while the sewage sludge a and the like in the sewage treatment plant remains in a slurry state. It is a device to be introduced directly. That is, the water-containing sludge a from the externally installed sludge receiving facility is once stored in the sludge tank 14 by the pressure feed pump 13, and from there, as needed, through the sludge introduction pipe 16 by the pressure feed pump 15 and the kiln bottom of the dry cement kiln 12. 12a. In addition, the temperature of the introduction location of the water-containing sludge a in the kiln bottom part 12a is 1000 degreeC. The end surface on the upper curved portion 16x side of the sludge introduction pipe 16 is aligned with the inner surface of the kiln bottom portion 12a (see FIG. 2).
[0028]
The in-pipe cleaning member 20 for cleaning the inside of the sludge introduction pipe 16 is a member whose main body is a cylindrical sponge having a diameter slightly larger than the inner diameter of the sludge introduction pipe 16, and whose one end face is coated with rubber 20a. When the in-pipe cleaning member 20 is inserted into the sludge introduction pipe 16, the rubber 20a side is inserted from the insertion port portion 24 in the traveling direction.
The cleaning water supply device 22 that supplies the cleaning water b into the sludge introduction pipe 16 includes a water storage tank 25 for the cleaning water b and a pumping pump 26 for the cleaning water b. Wash water b pumped to the sludge introduction pipe 16 side by the pressure feed pump 26 flows into the sludge introduction pipe 16 from the three-way valve 23 switched to the water wash side. Next, the tube end arrival detection device 10 will be described in detail with reference to FIG.
[0029]
As shown in FIG. 2, the tube end arrival detection device 10 is a rod-shaped detection member in which a tip portion is inserted into a pipe from an opening 16 a cut out in an upper curved portion 16 x at one end of a sludge introduction pipe 16. 27, an origin return spring 28 that extends due to the contact of the in-pipe cleaning member 20 with the detection member 27, and a limit switch 29 that is operated by the detection member 27. An intermediate portion of the detection member 27 is pivotally supported on a shaft support plate 30 that seals the opening 16 a of the sludge introduction pipe 16 via a rotation shaft 31.
The shaft support portion of the detection member 27 is covered with a bellows type cover 32 so that dust, dust, and the like are not attached thereto. One of the spring end portions of the origin return spring 28 is fixed to the projecting outer portion of the detection member 27, and the other end of the spring end is fixed to the outer peripheral surface of the kiln bottom portion 12 a of the dry cement kiln 12. Yes. The limit switch 29 is attached to the kiln bottom part 12a via a bracket (not shown).
[0030]
Next, a method for cleaning the sludge introduction pipe to which this piping structure is applied will be described.
As shown in FIG. 1, in the cement firing facility, the cement raw material is calcined while flowing down each cyclone of the preheater 11. Thereafter, the cement raw material flows into the kiln bottom 12a of the dry cement kiln 12 and is fired by the heat of the burner to become a cement clinker. At this time, the water-containing sludge a in the sludge tank 14 is introduced into the kiln bottom 12a of the dry cement kiln 12 by the sludge introduction device 21 through the sludge introduction pipe 16 at a rate of 4 t / h. It is poured into.
[0031]
The specific introduction of the hydrous sludge a into the kiln bottom 12a is temporarily stored in the sludge tank 14 from the sludge receiving facility (not shown) by the pressure pump 13, and then connected to the lower portion of the sludge tank 14 as needed. Then, the three-way valve 23 is introduced into the kiln bottom portion 12a of the dry cement kiln 12 through the sludge introduction pipe 16 that is switched to the sludge introduction side by the pressure feed pump 15. The hydrated sludge a after being charged can be incinerated economically by the burner heat at the time of firing the cement raw material without performing pretreatment such as deodorization, drying, and additive addition, which are expensive in advance.
[0032]
When cleaning the sludge introduction pipe 16, first, the water-containing sludge a remaining in the sludge introduction pipe 16 is removed while maintaining the operation of the dry cement kiln 12. That is, in the kiln operation state, the three-way valve 23 is switched from the sludge introduction side to the water washing side. Next, the in-pipe cleaning member 20 is inserted from the insertion port portion 24 with the rubber 20a side in the traveling direction. Then, the in-pipe cleaning member 20 is moved to one end side of the sludge introduction pipe 16 by the action of the washing water b fed by the pressure feed pump 26. Thereby, the hydrated sludge a remaining in the pipe is pushed out from the pipe end on the one end side of the sludge introduction pipe 16 where the upper curved portion 16x is provided.
Specifically, due to the action of the cleaning water, the in-pipe cleaning member 20 pushes behind the hydrated sludge a while scraping off some hydrated sludge a adhering to the inner peripheral surface of the sludge introduction pipe 16. Thereafter, the scraped and cleaned pipe inner peripheral surface is washed with washing water b. In addition, the water-containing sludge a pushed out from the pipe end is incinerated by the burning heat (about 1450 ° C.) of the cement raw material in the dry cement kiln 12 during normal operation.
[0033]
Next, when the in-pipe cleaning member 20 cleaning the inside of the sludge introduction pipe 16 comes into contact with the front end of the detection member 27 provided on the upper curved portion 16x of the sludge introduction pipe 16 during the in-pipe cleaning, the origin is restored. The spring 28 extends, and the detection member 27 rotates about the rotation shaft 31 to turn off the limit switch 29. Based on this switching, a pump operation stop command is issued from the control unit (not shown) toward the pumping pump 26, whereby the action of the back pressure by the wash water b is temporarily stopped. Thus, since the limit switch 29 type is adopted as the tube end arrival detection device 10, the cost of the device can be reduced.
[0034]
Thereafter, the action of the back pressure by the cleaning water b is resumed, and the cleaning water b in the upper curved portion 16x of the sludge introduction pipe 16 is discharged from the pipe end together with the in-pipe cleaning member 20 into the kiln kiln bottom side.
At this time, immediately after the in-pipe cleaning member 20 is pushed out from the sludge introduction pipe 16, the washing water b having good fluidity, which has applied the back pressure to the water-containing sludge a, is about to flow into the kiln kiln bottom side at once. To do. However, since the upper curved portion 16x higher than the normal height is provided near one end portion of the sludge introduction pipe 16, the flush water b is prevented from flowing out at once due to the height difference. Thereby, the rapid fall of the furnace temperature which generate | occur | produces when a lot of washing water b flows in into the kiln 12 can be prevented. As a result, it is possible to prevent damage to refractories stretched in the dry kiln 12 and deterioration of the quality of cement clinker produced in the middle due to this rapid temperature drop. The in-pipe cleaning member 20 and the washing water b discharged from the end of the sludge introduction pipe 16 are incinerated by the heat of baking in the kiln 12 or become steam.
[0035]
Further, the pipe cleaning member 20 that is moving in the sludge introduction pipe 16 is coated with the rubber 20a on one end surface thereof, so that it can receive the action of the back pressure by the washing water b without leaking. Thereby, the in-pipe cleaning member 20 can move in this pipe at a smooth speed. In addition, when the inside of the sludge introduction pipe 16 is cleaned, the peripheral surface of the sponge, which is an elastic body, is firmly attached to the inner peripheral surface of the sludge introduction pipe 6, so that the inside of the sludge introduction pipe 16 can be cleaned well. .
Further, since the in-pipe cleaning member 20 is manufactured from an inexpensive material such as sponge or rubber 20a, the in-pipe cleaning member 20 that is put into the high temperature kiln kiln bottom side and incinerated after washing is inexpensively manufactured. Can be manufactured.
[0036]
Furthermore, since the upper curved portion 16x of the sludge introduction pipe 16 is bent by one step upward in a step shape from the normal height of the pipe 16, the sludge introduction pipe 16 is easily raised at the time of manufacture. A curved portion 16x can be provided.
Furthermore, since the upper curved portion 16x is provided within 50 cm from the pipe end on one end side of the sludge introduction pipe 16, it is relatively easy to form the upper curved section 16x when the sludge introduction pipe 16 is manufactured, and the sludge introduction pipe When the water-containing sludge a is pushed out from the inside 16, the amount of the water-containing sludge a flowing slightly toward the bottom of the kiln kiln can be further reduced.
[0037]
Next, the piping structure of the sludge introduction pipe according to the second embodiment of the present invention will be described with reference to FIG.
FIG. 3 is a sectional view showing the main part of the sludge introduction pipe to which the sludge introduction pipe piping structure according to the second embodiment of the present invention is applied.
In the second embodiment, when the normal height of the sludge introduction pipe 40 is higher than the pipe end height H0 on the one end side of the sludge introduction pipe 40, the upper curved portion 40x once becomes the normal of the sludge introduction pipe 40. Bend upward (step height H2) by one step (height difference of 200 mm or more (pipe diameter or more)) from the height H1 and then descend by one step to the end height H0 of the sludge introduction pipe 40. This is an example.
[0038]
By doing in this way, the shape of the upper curved part 40x once bent upwards from the normal height H1 of the sludge introduction pipe 40 stepwise (height H2), and connected with the kiln kiln bottom side from there. Since one end is lowered to the height H0, even if the one end of the sludge introduction pipe 40 connected to the kiln kiln bottom side is a pipe path located at a position lower than the normal height H1 of the sludge introduction pipe 40. The cleaning water does not flow at a stroke due to the difference in height between the normal height H1 of the sludge introduction pipe 40 and the height H2 of the upper curved portion 40x. As a result, the above-described effects of preventing damage to the dry cement kiln 12 and deterioration of the quality of the cement clinker can be obtained.
Other configurations and functions and effects are the same as those of the first embodiment, and a description thereof will be omitted.
[0039]
【The invention's effect】
According to this invention, when cleaning the sludge introduction pipe, the water-containing sludge in the pipe is pushed out from the pipe end of the sludge introduction pipe, and at the same time, the washing water in the pipe tries to flow into the kiln kiln bottom side at once. Since an upper curved portion is provided in the vicinity of one end of the sludge introduction pipe, this washing water can be prevented from flowing out from the pipe end at a stretch. This prevents the dry cement kiln from being damaged and the quality of the cement clinker from being deteriorated due to a sudden drop in the temperature inside the kiln due to the wash water discharged in large quantities from the pipe end during cleaning of the sludge introduction pipe. Can do.
[0040]
In particular, according to the invention of claim 2, since the upper curved portion of the sludge introduction pipe is bent upward by one step in a step shape from the normal height of the pipe, at the time of manufacturing the sludge introduction pipe, Instead, it is possible to easily provide the upper curve portion.
[0041]
Furthermore, according to the invention described in claim 3, the shape of the upper curved portion is once bent upward in a step shape from the normal height of the sludge introduction pipe, and from there to one end height connected to the kiln kiln bottom side. Since the lower end of the sludge introduction pipe connected to the bottom of the kiln kiln is a pipe located at a position lower than the normal height of the sludge introduction pipe, there is no problem and the dry cement kiln described above. The effect of preventing damage and deterioration of cement clinker quality can be obtained.
[0042]
Furthermore, according to the invention of claim 4, since the upper curved portion is provided within 50 cm from the pipe end on one end side of the sludge introduction pipe, it is relatively easy to form the upper curved section when manufacturing the sludge introduction pipe. At the same time, when water-containing sludge is pushed out from the sludge introduction pipe, the amount of water-containing sludge that slightly flows to the kiln kiln bottom side can be further reduced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing a cement firing facility to which a sludge introduction pipe piping structure according to a first embodiment of the present invention is applied.
FIG. 2 is an enlarged sectional view showing a main part of the sludge introduction pipe according to the first embodiment of the present invention.
FIG. 3 is a cross-sectional view showing a main part of a sludge introduction pipe to which a sludge introduction pipe piping structure according to a second embodiment of the present invention is applied.
[Explanation of symbols]
10 In-pipe cleaning member sludge introduction pipe end arrival detection device,
11 Preheater,
12 Dry cement kiln,
12a Kiln bottom,
16, 40 sludge introduction pipe,
16x, 40x upper part,
a hydrous sludge,
b Wash water.

Claims (4)

One end is connected between the lower part of the preheater for cement raw material calcining and the kiln bottom of the dry cement kiln for firing cement raw material, and the piping structure of the sludge introduction pipe for introducing hydrous sludge into them. ,
By providing an upper curved portion bent upward in the vicinity of one end of the sludge introduction pipe, when cleaning water is pumped into the sludge introduction pipe to clean the pipe, The structure of the sludge inlet pipe that prevents the cleaning water in the pipe from flowing out from the pipe end of the sludge inlet pipe when the remaining water-containing sludge is pushed out from the pipe end on the one end side of the sludge inlet pipe. . 2. The sludge introduction pipe piping structure according to claim 1, wherein the upper curved portion is bent upward by one step from the normal height of the sludge introduction pipe. In the case where the normal height of the sludge introduction pipe is higher than the pipe end height on one end side of the sludge introduction pipe,
2. The sludge inlet pipe according to claim 1, wherein the upper curved portion is bent upward by one step from the normal height of the sludge inlet pipe and then descends to the height of one end of the sludge inlet pipe. Construction. The piping structure of the sludge introduction pipe according to any one of claims 1 to 3, wherein the upper curved portion is provided within 50 cm from a pipe end on one end side of the sludge introduction pipe.

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