JP3879194B2 - Water-containing sludge pressure feed control device for sludge treatment equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention is a device for controlling the amount of hydrous sludge fed to a sludge treatment facility, and more specifically, sewage sludge such as sewage sludge that has not been subjected to pretreatment such as drying and additive addition. The present invention relates to a hydrous sludge pressure feed amount control device for sludge treatment equipment, in which a fixed amount is pumped to a kiln bottom of a cement kiln and burned.
[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 underwater 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 technology in which water-containing sludge in a batch-type sludge hopper is directly introduced into the kiln bottom of a dry cement kiln (hereinafter sometimes simply referred to as dry kiln) or a preheater for incineration. . According to this technology, water-containing sludge is poured directly into an existing dry cement kiln or pre-heater with a pressure pump such as a double piston pump, without any pretreatment of drying or adding additives. Simultaneously with normal production of cement clinker, the water-containing sludge can be incinerated efficiently.
[0005]
[Problems to be solved by the invention]
  By the way, the moisture content of the hydrous sludge fed into the batch-type sludge hopper varies from day to day or even within a range of about 80 to 85%. This is because the sludge supply source is not constant and the weather changes over time. A batch-type sludge hopper is a hopper of a type in which sludge is supplied discontinuously and the storage amount constantly changes.
  In addition, such a change in moisture content is caused by a change in volumetric efficiency of a cylinder such as a pressure pump. In particular, in the case of a quantitative pump such as a double piston pump, this change has a great influence on the pumping amount of hydrous sludge to the dry kiln.
  That is, when the moisture content of the water-containing sludge changes, the operating conditions of the dry kiln for firing cement clinker change, resulting in intermediate production of defective cement clinker or laying on the inner peripheral surface of the dry kiln. There was a risk that the refractory was damaged by the heat of firing.
[0006]
  Further, when the amount of sludge in the batch-type sludge hopper increases or decreases, the back pressure applied from the sludge hopper side that is a pressure supply source increases or decreases with respect to the water-containing sludge that is being pumped. As a result, the density of the water-containing sludge pushed into the cylinder of the pressure-feed pump changes, the pressure-feed amount of the water-containing sludge also changes, and the operating conditions of the dry kiln are similarly disturbed, resulting in defective cement clinker products and fire resistance of the dry kiln. There was a risk of damage. Therefore, in order not to cause such inconvenience, quantitative control of hydrous sludge is important.
  As a specific example of the quantitative control, for example, it is conceivable to directly measure the flow rate of hydrous sludge fed from a sludge hopper using a flow sensor. However, a sensor that can directly measure the flow rate of water-containing sludge being pumped by a pump has not been developed yet. As a result, there is a problem that this quantitative control cannot actually be performed.
[0007]
OBJECT OF THE INVENTION
  An object of the present invention is to provide a hydrous sludge pressure feed amount control device of a sludge treatment facility capable of performing quantitative control of hydrous sludge being pumped. Another object of the present invention is to provide a hydrous sludge pumping amount control device for a sludge treatment facility that can more accurately pump hydrous sludge more accurately and has good hydrous sludge pumping efficiency. Furthermore, an object of the present invention is to provide a hydrous sludge pressure feed amount control device for a sludge treatment facility that can detect the amount of residual sludge in a sludge reservoir at a relatively low cost.
[0008]
[Means for Solving the Problems]
  According to the first aspect of the present invention, the water-containing sludge stored in the batch-type sludge reservoir is disposed between the lower part of the preheater for cement raw material calcining and the kiln bottom of the dry cement kiln for cement raw material firing. A device for controlling the amount of water-containing sludge in a sludge treatment facility that is pumped through a sludge introduction pipe, wherein the water-containing sludge in the sludge storage section is pumped to the outlet side of the sludge introduction pipe, and the sludge storage section Based on the sludge weight measurement signal from the sludge weight measurement means and the sludge weight measurement signal from the sludge weight measurement means, the pumping amount of the water-containing sludge by the pumping means is controlled, and the sludge introduction pipe is led to the outlet side. A control means for making the pumping amount of the hydrous sludge pumped constant,In the above-mentioned pumping means, a double piston pump having two pistons that switch between the suction side and the discharge side of the water-containing sludge for each stroke, or in a spiral channel having an oval cross section formed inside a cylindrical stator Is a single-shaft eccentric screw pump that delivers a fixed amount of water-containing sludge by reciprocating the rotor with a round rod and rotating around its eccentric axis.This is a device for controlling the amount of hydrous sludge pumped by a sludge treatment facility.
[0009]
  Examples of the water-containing sludge here include sewage sludge, activated sludge, and sludge.
  The water-containing sludge may be supplied directly from the sludge treatment facility to the sludge storage section through a pipeline or the like, or may be transported by a truck equipped with a sealed tank and put into the sludge storage section.
  Moreover, as a batch type sludge storage part to which sludge is intermittently supplied, the sludge hopper etc. in which the lower part provided with the mere sludge tank and the discharge port taper gradually are mentioned, for example. Of these, the latter, a sludge hopper, in which the hydrated sludge is stored and the stored hydrated sludge is pushed out from the lower discharge port by its own weight is preferable.
[0010]
  Although there is no restriction | limiting in particular in the input amount of the water-containing sludge to the dry kiln by a sludge introduction pipe | tube, 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 input amount of the hydrous sludge is 9 to 10.0 t / h, which is 1/10 or less of the weight of the cement clinker to be manufactured. It is preferable to introduce hydrous sludge. This is because if the input amount of the water-containing sludge with respect 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. Moreover, when it exceeds 1000 degreeC, the malfunction which will interfere with furnace operation will arise.
[0012]
  Examples of the water-containing sludge pumping means herein include a double piston pump and a rotary volume type uniaxial eccentric screw pump.
  The double piston pump here is, for example, two parallel hydraulic cylinders connected to one side wall of a sealed box-shaped sludge tank for storing hydrous sludge, and a rotation extending in the pipe axis direction in the sludge tank. An S-type oscillating tube that oscillates about 120 ° around the axis is pivotally supported (see FIG. 2). The piston of each hydraulic cylinder is designed so that the pushing and pulling directions are opposite to each other. When one piston moves in the protruding direction, the other moves in the retracting direction. In each cylinder, the S-shaped swing pipe is swung for each stroke of the piston, so that the inlet of the swing pipe is switched to one of the discharge ports of both hydraulic cylinders. .
[0013]
  The two hydraulic cylinders arranged side by side may be arranged horizontally or vertically. In addition, for supplying the water-containing sludge into the storage unit, for example, a screw conveyor that pushes out the water-containing sludge from the discharge port by the action of a screw may be used (see also FIG. 2).
  Further, the uniaxial eccentric screw pump (commonly referred to as a snake pump) referred to here may be one in which the axial direction of the stator is horizontal or vertical. Usually, the stator has a cylindrical shape, and an elastic material such as rubber or synthetic resin is generally used for a portion where the spiral flow path is formed. However, the spiral channel forming portion is not limited to this, and may be a rigid body such as a metal.
[0014]
  In addition, as a means for measuring the sludge weight of the water-containing sludge, for example, a load cell that detects the weight of the water-containing sludge according to claim 2, as long as it can measure the weight of the water-containing sludge remaining in the sludge reservoir. It is not limited.
  As the control means, for example, well-known electrical and electronic control means such as a computer including a CPU can be employed.
[0015]
  The invention described in claim 2 is the apparatus for controlling the amount of hydrous sludge pumped in the sludge treatment facility according to claim 1, wherein the sludge weight measuring means includes a load cell.
  A well-known load cell can be used. Moreover, the installation position in the sludge storage part of this load cell will not be limited if it is a position (usually the lower part of a sludge storage part) which can detect the sludge weight which remained in the sludge storage part.
[0016]
[Action]
  According to this invention,Between the lower part of the pre-heater and the kiln bottom of the dry cement kiln, the water-containing sludge in the batch-type sludge reservoir is pumped through the sludge inlet pipe by the pumping means, and this pumped water-containing sludge is calcined by the cement material. To burn. The incinerated ash containing heavy metals useful for cement is dispersed by the rotation of the dry cement kiln during firing and adheres to the surface of the cement clinker.
  During sludge pumping, the sludge weight in the sludge storage part at a certain time before the predetermined time elapses and the sludge weight after the predetermined time has elapsed are measured by the sludge weight measuring means. Calculate the amount of hydrous sludge pumped to the kiln kiln bottom. And the sludge pumping amount per unit time is calculated from the pumped amount of the obtained water-containing sludge, and the difference value between this calculated value and a preset target sludge pumping amount is obtained, and then this difference disappears. As described above, the pumping amount of the water-containing sludge is controlled by the control means. Thereby, the water-containing sludge can be quantitatively controlled during the pressure feeding.
[0017]
  When the pressure-feeding means is a double piston pump, the water-containing sludge is quantitatively pumped to the outlet side of the sludge introduction pipe by the double piston pump while switching between the suction side and the pressure-feed (discharge) side of the water-containing sludge. As a result, the water-containing sludge can be quantitatively pumped more accurately, and the pumping efficiency of the water-containing sludge can be improved.
Further, when the pumping means is a uniaxial eccentric screw pump, a spiral rod-shaped rotor having a perfectly circular cross section reciprocates while rotating around the eccentric axis in a spiral flow path having an elliptical cross section of a cylindrical stator. . Thereby, the water-containing sludge is quantitatively transferred continuously without pulsation.
[0018]
  In particular,According to invention of Claim 2,At the time of measuring the weight of the hydrous sludge remaining in the sludge reservoir, the remaining sludge weight is measured based on the sludge weight measurement signal of the load cell, so that the equipment cost for the measurement is relatively low.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, the present invention will be described in detail with reference to the drawings. First, a first embodiment of the present invention will be described.
  FIG. 1 is a schematic cross-sectional view of a cement firing facility equipped with a water-containing sludge pressure feed control device for a sludge treatment facility according to a first embodiment of the present invention. FIG. 2 is an enlarged perspective view of the double piston pump for pumping.
  In FIG. 1, A is the sludge treatment facility according to the first embodiment, and this sludge treatment facility A is connected to the cement firing facility 1 of the cement manufacturing plant in line, thereby utilizing the heat at the time of firing the cement raw material a. And incinerate the water-containing sludge b. First, the cement firing facility 1 will be described.
  The cement firing facility 1 is an facility for intermediately producing a cement clinker a0 by firing the cement raw material a calcined in the preheater 2 in a dry cement kiln 4. In addition, the dry-type cement kiln 4 used here shall produce the cement clinker a0 at 90-100 t / h.
[0020]
  The preheater 2 preheats the cement raw material a 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 4. The pre-heater 2 is provided with a large number of cyclones 2a mounted on a several-storey steel frame 2b. Further, the uppermost cyclone 2a is connected to a gas exhaust system that has a fan (not shown) and guides the gas generated during calcination to the gas processing facility.
[0021]
  The dry cement kiln 4 has a horizontal cylindrical kiln shell 4a inclined slightly downward toward the downstream side. A refractory is stretched on the inner peripheral surface of the kiln shell 4a.
  While the kiln shell 4a is rotated in the circumferential direction, the calcined cement raw material a from the preheater 2 is fired by heating with the burner 4b using heavy oil or fine coal as fuel, and the cement clinker a0 is intermediately produced. Thereafter, the cement clinker a0 is cooled by the clinker cooler 4c connected to the downstream portion of the dry cement kiln 4 and sent to the finishing process.
[0022]
  Next, the sludge treatment facility A will be described.
  As shown in FIG. 1, the sludge treatment facility A has a volume of 100 m, which is an example of a sludge storage unit.³ And a sludge introduction device 6 for introducing the water-containing sludge b in the hopper 5 into the kiln bottom portion 4 d of the dry cement kiln 4. For example, the lower portion of the storage hopper 5 is buried in the soil. Moreover, this storage hopper 5 is a batch type, and it is the structure by which sludge is supplied into the inside intermittently or intermittently.
[0023]
  Next, the sludge introduction device 6 will be described in detail with reference to FIGS.
  As shown in FIGS. 1 and 2, the sludge introduction device 6 includes a screw-type cutting conveyor 10 that is provided at the lower portion of the storage hopper 5 and continuously cuts out the water-containing sludge b in the tank by a predetermined amount. Yes. A screw conveyor 11 that houses two screws 11 a aligned in the axial direction is disposed downstream of the cutout conveyor 10. The hydrous sludge b discharged from the screw conveyor 11 is introduced into the sludge introduction pipe 12 by a double piston pump 13 which is an example of a pressure feeding means. The sludge introduction pipe 12 has a pipe end on the outlet side of the water-containing sludge b connected to and connected to the kiln bottom part 4b.
  In addition, a load cell 14 that is an example of a sludge weight measuring unit that measures the weight of the water-containing sludge b introduced from the truck 8 on which a sealed tank is mounted is provided below the storage hopper 5. The load cell 14 is electrically connected to the control means 15 which is a computer. Based on the sludge weight measurement signal from the load cell 14, the control means 15 controls the pumping amount of the water-containing sludge b to the kiln kiln bottom side 4 b by the double piston pump 13. Specifically, for example, the number of strokes per unit time of the pistons 17a and 18a is increased or decreased to control the stroke speed of the pistons 17a and 18a. At this time, the cutout conveyor 10 and the screw conveyor 11 also control the drive of the drive unit as necessary.
[0024]
  Next, the double piston pump 13 will be described in detail with reference to FIG.
  As shown in FIG. 2, the double piston pump 13 is a biaxial pump that pumps the hydrous sludge b at 4 t / h. In the double piston pump 13, two parallel hydraulic cylinders 17 and 18 are connected and connected to one side wall of a sealed box-like sludge tank 16 for storing the hydrated sludge b. Further, in the sludge tank 16, an S-shaped swing pipe 20 that swings by approximately 120 ° about a rotary shaft 19 extending in the pipe axis direction is pivotally supported. The tube end portion on the outlet side of the water-containing sludge b of the S-shaped rocking tube 20 is pivotally supported by the discharge portion 16a of the sludge tank 16 so as to be rotatable in the circumferential direction.
  The pistons 17a and 18a of the hydraulic cylinders 17 and 18 are designed so that the directions of pushing and pulling are opposite to each other during operation. On the outer surface of one side wall of the sludge tank 16, a pair of hydraulic cylinders 21 each having a piston rod tip extending to one end of the rotating shaft 19 are disposed.
[0025]
  The piston 17a, 18a side of the double piston pump 13 is switched to the suction side and the pressure feed side of the water-containing sludge b for each stroke, and at the same time, the piston rods of the respective hydraulic cylinders 21 are taken in and out, and the rotary shaft 19 is centered. The S-shaped swing tube 20 is swung in a vertical plane. As a result, the inlet 20a of the S-shaped rocking pipe 20 is switched to one of the outlets 17b and 18b of the hydraulic cylinders 17 and 18, and the hydrous sludge b passes through the sludge inlet pipe 12 to the kiln bottom. It is pumped in a fixed state into the part 4d.
  The sludge introduction pipe 12 is configured by a pipe body that connects and connects the storage hopper 5 and the kiln bottom part 4 d of the dry cement kiln 4. The double piston pump 13 pumps the hydrous sludge b through the sludge introduction pipe 12.
[0026]
  Next, the control means 15 will be described in detail with reference to FIGS.
  FIG. 3 is a schematic diagram of a water-containing sludge pressure feed amount control device of the sludge treatment facility according to the first embodiment of the present invention. FIG. 4 is a schematic diagram showing the hardware configuration of the control means of the first embodiment of the present invention. FIG. 5 is a flowchart showing the control of the amount of hydrous sludge pumped by the sludge treatment facility by the control means of the first embodiment of the present invention.
  As shown in FIG. 3, a load cell 14 and a timer 30 are connected to the control means 15 on the input side. On the other hand, a cutting conveyor 10, a screw conveyor 11, a double piston pump 13, and the like are connected to the output side. The control means 15 has a general configuration. That is, as shown in FIG. 4, a CPU 31 as a central processing unit, a ROM 32 and a RAM 33 as memories, and an I / O port 34 as an input / output port are connected by a bus.
[0027]
  This control means 15 is configured to determine the difference between the sludge weight before and after a predetermined time by the timer 30 during the pumping of the water-containing sludge b from the batch-type sludge tank 16 to the kiln bottom 4d. Obtained based on the measurement signal, and based on this, calculate the amount of sludge pumped to the kiln butt 4b and water content so that the obtained value matches the set sludge pumped amount Controls sludge a feeding. During this control, the cutout conveyor 10 and the screw conveyor 11 are also controlled as necessary.
  As described above, the hydrous sludge pressure feed amount control device B of the sludge treatment facility is constituted by these components 10, 11, 13 to 15. In FIG. 2, 11 b is the inlet of the water-containing sludge b of the screw conveyor 11, 11 c is the rotating shaft of the screw 11 a, 22 is the tip of the rod of both hydraulic cylinders 21 and one end of the rotating shaft 19. It is a ball seat-like connecting part.
[0028]
  Next, the operation of the sludge treatment facility A and the cement firing facility 1 of the first embodiment will be described.
  As shown in FIG. 1, the hydrated sludge b is put into the storage hopper 5 in advance by a truck 8. Moreover, the cement raw material a is calcined while flowing down each cyclone 2a of the preheater 2. Thereafter, the cement raw material a flows into the kiln bottom 4d of the dry cement kiln 4 and is baked by the heat of the burner 4b to become a cement clinker a0.
  At this time, in the kiln bottom 4d of the dry cement kiln 4, the water-containing sludge b in the sludge hopper 5 is fixed at, for example, 4 t / h through the sludge introduction pipe 12 by the double piston pump 13 of the sludge introduction device 6. Poured in quantity. That is, the hydrous sludge b is thrown into the one end part side of the screw conveyor 11 from the cutout conveyor 10 side through the inlet 11b. Next, the water-containing sludge b is continuously fed into the sludge tank 16 of the double piston pump 13 by a pair of screws 11a. Further, the water-containing sludge b is pumped into the sludge introduction pipe 12.
[0029]
  Specifically, the water-containing sludge b in the sludge hopper 5 is thrown into the one end part side of the screw conveyor 11 from the cutout conveyor 10 side through the loading port 11b. Next, the water-containing sludge b is continuously fed into the sludge tank 16 of the double piston pump 13 by a pair of screws 11a.
  In the double piston pump 13, the pistons 17 a and 18 a are switched between the suction side and the pressure feeding side of the hydrated sludge b for each stroke by a pair of hydraulic cylinders 17 and 18. At the same time, the rods of the respective hydraulic cylinders 21 are taken in and out, and the S-shaped swing pipe 20 swings in the vertical plane around the rotary shaft 19, so that the water-containing sludge b of the S-shaped swing pipe 20 is obtained. The inlet 20a is switched to one of the discharge ports 17b and 18b on the pressure feeding side of both the hydraulic cylinders 17 and 18.
[0030]
  That is, the water-containing sludge b in the sludge tank 16 is sucked into the suction-side hydraulic cylinder 17 or 18, while the water-containing sludge b is connected to the pressure-feed hydraulic cylinder 18 or 17. 20 is discharged from the discharge part 16a of the sludge tank 16 into the sludge introduction pipe 12. Thereafter, the water-containing sludge is obtained by switching between the suction side and the pressure-feed side of the hydraulic cylinders 17 and 18 and by connecting the inlet 20a of the S-shaped swing pipe 20 by swinging using both relatively small hydraulic cylinders 21. b is intermittently introduced into the kiln bottom 4d of the dry cement kiln 4 through the sludge introduction pipe 12 for each stroke of the double piston pump 13.
[0031]
  In this way, while the hydrous sludge b is being pumped from the batch-type sludge hopper 5 to the kiln bottom part 4d, the difference X between the sludge weights before and after a predetermined time is obtained, and based on this, the pump is pumped to the kiln bottom part 4d. The amount of sludge Y per unit time was calculated, and the pumping of the hydrous sludge b was controlled so that the obtained value Y matched the preset sludge pumping amount Z. The quantitative control of the sludge b can be performed relatively easily.
  That is, in the case of a metering pump such as the double piston pump 13, the change in the moisture content of the water-containing sludge b and the back pressure of the water-containing sludge b during pumping due to the weight of the water-containing sludge b remaining in the sludge hopper 5 There is a possibility that the volumetric efficiency of the cylinder of the double piston pump 13 may change due to a change or the like.
  If the water content of the water-containing sludge b changes, for example, the operating conditions of the dry kiln for firing the cement clinker will change, and there is a risk that a defective cement clinker will be intermediately produced. Moreover, when the water content is high, the refractory laid on the inner peripheral surface of the dry kiln may be damaged by the heat of firing.
[0032]
  Therefore, in this embodiment, the preset amount Z of the water-containing sludge b per unit time was considered as a guideline (target value) of the pressure control. As a result, the actual sludge pumping amount Y per unit time is calculated from the pumped amount X of the water-containing sludge b pumped during a predetermined time (15 minutes), and this value Y and the set sludge pumping amount Z are calculated. The fundamental idea of the present invention is to obtain the difference R, and increase / decrease the sludge pumping amount per unit time by this difference R to correct the water-containing sludge pumping amount to the target value. is there.
[0033]
  Further, since the load cell 14 is used to measure the weight of the hydrated sludge b remaining in the sludge hopper 5, the equipment cost is relatively low.
  Further, since the water-containing sludge b accumulated in the sludge hopper 5 is pumped to the kiln bottom 4d by the double piston pump 13, the water-containing sludge b can be quantitatively pumped more accurately, and the water-containing sludge b can be pumped. Efficiency is also good.
[0034]
  Here, with reference to the flowchart of FIG. 5, a specific method for controlling the amount of water-containing sludge b fed into the kiln bottom 4d will be described. This program is repeatedly executed every predetermined time.
  As shown in FIG. 5, when the program is executed, in step 101, it is determined whether or not the water-containing sludge b is introduced into the storage hopper 5 by an input signal from the load cell 14 or the like. Proceed to In this step, the load cell 14 measures the sludge weight n of the water-containing sludge b at a predetermined time after the sludge is charged. Then, it progresses to step 103 and the timer 30 measures that 15 minutes have passed since then. In step 104, the sludge weight p after the lapse of 15 minutes is measured. Then, the process proceeds to step 105, the sludge weight n-sludge weight p is calculated, and the pumping amount X of the hydrous sludge b pumped into the kiln bottom 4b is calculated for 15 minutes (for example, X = n−p ).
[0035]
  Next, in step 106, the pumping amount X of the water-containing sludge b is divided by the elapsed time to obtain a sludge pumping amount Y per unit time (Y = X / T). Subsequently, in step 107, a difference R between the sludge pumping amount Y and the set sludge pumping amount Z stored in advance in the RAM 33 (see FIG. 4) of the control means 15 is obtained (R = | Y−Z |).
  Then, the output to the drive unit of the double piston pump 13 operating at a constant stroke speed is increased or decreased by the amount R of the obtained sludge pumping amount (step 108). That is, when the value of the difference R is positive, the output of the double piston pump 13 (stroke speed of the pistons 17a and 18a) is reduced by the difference R, and the value is maintained if the difference matches. On the other hand, if the value of the difference R is negative, the output of the double piston pump 13 (stroke speed of the pistons 17a, 18a) is increased by the difference R, and if the difference matches (for example, a deviation of 0.1). Keep that value (within seconds). If the values match from the beginning, the value is maintained without increasing or decreasing the output of the double piston pump 13. Thereafter, this routine is terminated.
[0036]
  In step 101, if the sludge is not input, the process proceeds to step 102, where it is determined whether or not the second and subsequent sludge control is performed. That is, in the second and subsequent times, the process proceeds to step 102, and when waiting for the first water-containing sludge b to be input, the process is returned to step 101 in sequence, and the sludge input standby state is entered. By the way, during the quantitative control of the water-containing sludge b, when the water-containing sludge b is newly input from the truck 8 into the sludge hopper 5, from the step 101, as in the case of the initial water-containing sludge b being input, Proceed directly to step 102.
[0037]
  Next, based on FIG. 6, a method and apparatus for controlling the amount of water-containing sludge in a sludge treatment facility according to the second embodiment of the present invention will be described.
  FIG. 6 is a longitudinal sectional view of a uniaxial eccentric screw pump in the method and apparatus for controlling the amount of hydrous sludge pumped in the sludge treatment facility according to the second embodiment of the present invention.
  As shown in FIG. 6, the sludge introduction device 40 of the sludge treatment facility of the second embodiment employs a uniaxial eccentric screw pump 50 as a pressure feeding means for pressure-feeding the hydrous sludge b to the outlet side of the sludge introduction pipe 12. It is. The uniaxial eccentric screw pump 50 is connected to a sealed box-like sludge tank 51, a water-containing sludge b inlet 52 connected to the upper opening of the sludge tank 51, and an opening on one side of the sludge tank 51. It is connected to the drive motor 53 and the opening on the other side of the sludge tank 51, and is housed in a cylindrical rubber stator 54 having a spiral flow path having an oval cross section and a spiral flow path 54 a of the stator 54. A spiral rod-shaped rotor 55 that is a spiral rod having a perfect cross section is provided, and a coupling rod 56 that connects the base of the rotor 55 and the output shaft of the drive motor 53 is provided.
[0038]
  When the output shaft is rotated by the drive motor 53, the rotor 55 reciprocates in the spiral flow path 54 a of the stator 54 while rotating around the eccentric axis through the coupling rod 56. Thereby, the water-containing sludge b introduced into the sludge tank 51 from the inlet 52 is continuously and quantitatively transferred without pulsation toward the outlet side of the sludge introduction pipe 12.
  In this case, the control of the pumping amount of the water-containing sludge is performed by controlling the rotational speed of the drive motor 53. That is, when the actual pumping amount is less than the target value, the rotational speed is increased, and conversely, when it is large, the motor rotational speed is decreased.
[0039]
【The invention's effect】
  According to this invention, while pumping the water-containing sludge from the batch-type sludge reservoir to the kiln kiln bottom side, the difference in the sludge weight before and after the predetermined time has passed is obtained, and based on this, the kiln kiln bottom side Since the amount of sludge per unit time that was pumped to the unit was calculated, and the hydrous sludge pumping was controlled by the control means so that the obtained value matched the preset sludge pumping amount, Quantitative control of water-containing sludge can be performed relatively easily.
  When the pumping means is a double piston pump, the water-containing sludge accumulated in the sludge storage section is doubled. Since it is pumped to the kiln kiln bottom side by the piston pump, the hydrous sludge can be quantitatively pumped more accurately, and the pumping efficiency of the hydrous sludge can be improved.
In the case where the pumping means is a uniaxial eccentric screw pump, the hydrous sludge can be continuously and quantitatively transferred without pulsation because the rotor having a perfectly circular cross section is reciprocated while rotating around the eccentric axis within the helical flow path of the stator.
[0040]
In particular, according to the invention of claim 2,Since the weight of the hydrated sludge remaining in the sludge reservoir is measured by the load cell, the equipment cost is relatively low.
[0041]
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of a cement firing facility equipped with a water-containing sludge pressure feed rate control device of a sludge treatment facility according to a first embodiment of the present invention.
FIG. 2 is a perspective view showing a double piston pump according to a first embodiment of the present invention.
FIG. 3 is a block diagram showing a hydrous sludge pumping amount control device of the sludge treatment facility according to the first embodiment of the present invention.
FIG. 4 is a schematic diagram showing a hardware configuration of control means according to the first embodiment of the present invention.
FIG. 5 is a flowchart showing the control of the amount of water-containing sludge in the sludge treatment facility by the control means according to the first embodiment of the present invention.
FIG. 6 is a longitudinal sectional view of a uniaxial eccentric screw pump in the method and apparatus for controlling the amount of hydrous sludge pumped in the sludge treatment facility according to the second embodiment of the present invention.
[Explanation of symbols]
  1 sludge treatment equipment,
  2 Preheater,
  4 Dry cement kiln,
  4d kiln bottom,
  12 Sludge introduction pipe,
  13 Double piston pump (pressure feeding means),
  14 Load cell (sludge weight measuring means),
  15 control means,
  40 Sludge introduction equipment for sludge treatment equipment,
  50 uniaxial eccentric screw pump (pressure feeding means),
  53 drive motor,
  54 Stator,
  54a spiral channel,
  55 rotor,
  B. Sludge treatment equipment hydrous sludge pressure feed control device,
  R Difference between sludge pumping amount per unit time and set sludge pumping amount,
  X Sludge pumping amount in a certain time,
  Y sludge pumping amount per unit time,
  a Cement raw material,
  b Water-containing sludge,
  n Sludge weight before a certain period of time
  p Sludge weight after a certain period of time.

Claims (2)

Between the lower part of the preheater for cement raw material calcining and the kiln bottom of the dry cement kiln for cement raw material firing, the hydrous sludge stored in the batch type sludge storage part is pumped through the sludge introduction pipe A device for controlling the amount of hydrous sludge fed to a sludge treatment facility,
A pumping means for pumping the water-containing sludge in the sludge reservoir to the outlet side of the sludge introduction pipe;
Sludge weight measuring means for measuring the weight of the water-containing sludge in the sludge reservoir,
Control means for controlling the amount of water-containing sludge pumped by the pressure-feeding means based on the sludge weight measurement signal from the sludge weight-measuring means so that the amount of water-containing sludge pumped to the outlet side of the sludge introduction pipe is constant. And
The pumping means is
A double piston pump having two pistons that switch between the suction side and the discharge side of the water-containing sludge for each stroke;
Alternatively, the water-containing sludge is quantitatively transferred by reciprocating the rotor of a spiral rod-shaped rotor having a perfect circular shape and rotating around its eccentric axis in a spiral flow passage formed inside the cylindrical stator. Water-containing sludge pressure feed control device for sludge treatment equipment that is a uniaxial eccentric screw pump . The apparatus for controlling the amount of hydrous sludge in a sludge treatment facility according to claim 1, wherein the sludge weight measuring means includes a load cell.

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