Sludge transportation drying device, control device and sludge belt dryer

Abstract

The present application relates to a kind of sludge transport drying device, control device and sludge belt dryer.Therein, the sludge transport drying device includes transfer device and dryer;The transfer device includes transfer bin, transfer conveyor and bridge breaking device;Sludge falls through the transfer bin to the transfer conveyor;The transfer conveyor transports sludge to the dryer;The bridge breaking device is arranged above the bottom outlet of the transfer bin, for breaking bridge when sludge forms bridge phenomenon;Including first material level sensor and controller;The first material level sensor detects the sludge material level in the transfer bin, and transmits the detected first material level data to the controller;The controller determines whether the transfer bin occurs bridge phenomenon according to the first material level data;If bridge phenomenon occurs, the controller starts bridge breaking device.The present application automatically detects bridge and automatically breaks bridge by setting material level sensor, more intelligent.

Description

Technical Field

[0001] This invention relates to sludge belt dryers, and more particularly to a sludge transport and drying device, a control device, and a sludge belt dryer. Background Technology

[0002] Existing technology includes a sludge belt dryer, which at least comprises a dewatering machine, a transfer device, and a dryer. After entering the dewatering machine, the sludge undergoes preliminary dewatering treatment, becoming sludge with a moisture content of 70%. Then, it enters the dryer through the transfer device, undergoes drying treatment, and becomes sludge with a moisture content of 35%, before proceeding to the next processing stage.

[0003] The transfer device includes a transfer hopper, a bridging device, and a transfer conveyor belt. The transfer hopper is funnel-shaped with a larger top inlet and a smaller bottom outlet. The bridging device is located above the bottom outlet of the transfer hopper and is used to break up bridging phenomena that occur when sludge forms bridges in the transfer hopper. The dryer includes a hopper, a granulator, and a drying conveyor belt. The hopper is also funnel-shaped with a larger top inlet and a smaller bottom outlet. The granulator transforms the sludge from a muddy state into granules to facilitate drying.

[0004] Sludge with a moisture content of 70% enters the transfer silo through the top inlet and then enters the transfer conveyor belt through the bottom outlet. The transfer conveyor belt then transports the sludge to the hopper of the dryer. The sludge enters the hopper through the top inlet and then enters the granulator through the bottom outlet. The granulator transforms the sludge from a muddy state into granules, which are then fed into the drying conveyor belt for drying, yielding sludge with a moisture content of 35%.

[0005] However, existing sludge belt dryers have the following drawbacks: they require manual judgment to determine whether bridging has occurred in the transfer silo; when bridging is detected, the bridging breaking device must be manually activated. This existing bridging control method is not intelligent enough and requires significant manpower. Summary of the Invention

[0006] Based on this, the purpose of the present invention is to provide a sludge transport and drying device, a control device, and a sludge belt dryer that can automatically control the start and stop of the bridge breaking device.

[0007] A sludge transport and drying device includes a transfer unit and a dryer; the transfer unit includes a transfer hopper, a transfer conveyor belt, and a bridging device; sludge falls from the transfer hopper onto the transfer conveyor belt; the transfer conveyor belt transports the sludge to the dryer; the bridging device is located above the bottom outlet of the transfer hopper and is used to break up bridging when sludge bridging occurs; it includes a first level sensor and a controller; the first level sensor detects the sludge level in the transfer hopper and transmits the detected first level data to the controller; the controller determines whether bridging has occurred in the transfer hopper based on the first level data; if bridging occurs, the controller activates the bridging device.

[0008] Furthermore, the controller determines whether bridging has occurred in the transfer silo based on the first material level data. Specifically, the controller determines that bridging has occurred when the first material level data is higher than 50% of the capacity of the transfer silo or when no sludge is detected falling at the bottom outlet of the transfer silo; and determines that the bridging has disappeared when the first material level data is lower than 50% of the capacity of the transfer silo and sludge is detected falling at the bottom outlet of the transfer silo.

[0009] Furthermore, the bridge-breaking device includes a bridge-breaking motor and several rakes connected to the controller; when the bridge-breaking device is started, the bridge-breaking motor rotates, driving the rakes to rotate, and the rotating rakes agitate the sludge in the transfer silo, thereby breaking the bridge; when the controller determines that a bridging phenomenon has occurred, it controls the speed of the bridge-breaking motor according to the first material level data.

[0010] Furthermore, when the controller determines that bridging has occurred, it controls the speed of the bridging motor according to the first material level data. Specifically, the speed of the bridging motor is linearly positively correlated with the magnitude of the first material level data; when the first material level data is 50%, the speed of the bridging motor is the initial speed of the motor; when the first material level data is 90% of the capacity of the transfer hopper, the speed of the bridging motor is the set first maximum speed value.

[0011] Furthermore, the transfer device also includes a feeding motor connected to the controller; the feeding motor controls the start, stop, and speed of the transfer conveyor belt; the dryer also includes a hopper and a granulator; the transfer conveyor belt transports sludge to the top inlet of the hopper; the sludge enters the hopper from the top inlet and then exits from the bottom outlet of the hopper into the granulator; the sludge transport and drying device also includes a second level sensor; the second level sensor detects the sludge level in the hopper and transmits the detected second level data to the controller; the controller adjusts the rotation speed of the feeding motor according to the second level data; specifically, the rotation speed of the feeding motor is negatively correlated with the second level data.

[0012] Furthermore, the rotational speed of the feeding motor is negatively correlated with the second material level data, specifically: the rotational speed of the feeding motor is linearly negatively correlated with the second material level data; when the second material level data is 0, the rotational speed of the feeding motor is the set second maximum rotational speed; when the second material level data is 90% of the hopper capacity, the rotational speed of the feeding motor is 0.

[0013] Furthermore, when the controller determines that bridging has occurred and the second material level data is not higher than 70% of the hopper capacity, it reduces the speed of the feeding motor. Specifically, this includes: recording the original speed of the feeding motor, subtracting a fixed value from the original speed to obtain a new speed, and using the new speed as the new speed of the feeding motor.

[0014] Furthermore, when the controller determines that bridging has occurred, it starts the bridging motor and controls its speed according to the first material level data, while simultaneously adjusting the speed of the feeding motor according to the second material level data. Then, it checks every 2 minutes whether the bridging has disappeared. If the bridging has disappeared for 5 to 7 consecutive cycles, it stops the bridging motor and restores the speed of the feeding motor. Otherwise, it continuously increases the speed of the bridging motor until it reaches the set first maximum speed value.

[0015] Based on the same inventive concept, the present invention also provides a control device applied to a sludge transport and drying device including a transfer unit, wherein the transfer unit includes a transfer silo and a bridging device; it includes a first level sensor and a controller; the first level sensor detects the sludge level in the transfer silo and transmits the detected first level data to the controller; the controller determines whether bridging occurs in the transfer silo based on the first level data; if bridging occurs, the controller activates the bridging device.

[0016] Based on the same inventive concept, the present invention also provides a sludge belt dryer, including any of the above-mentioned sludge transport and drying devices.

[0017] The sludge transport and drying device of the present invention can not only automatically break bridges by collecting the first material level data from the first material level sensor, but also flexibly adjust the speed of the bridge breaking motor and the feeding motor according to the first material level data and the second material level data, thereby maintaining the relative stability of the material level in the hopper and effectively preventing the sludge in the hopper from being too low or overflowing. Compared with the existing bridge breaking control method, it is more flexible and intelligent.

[0018] To better understand and implement this invention, the following detailed description is provided in conjunction with the accompanying drawings. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the sludge transport and drying device of the present invention;

[0020] Figure 2 This is a schematic diagram of the sludge transport and drying device of the present invention;

[0021] Figure 3 A schematic diagram illustrating the process by which the controller determines whether a bridging phenomenon has occurred. Detailed Implementation

[0022] This invention automatically detects whether sludge bridging occurs by installing a first level sensor at the transfer silo and a second level sensor at the hopper, thereby automatically triggering a bridging-breaking device. Furthermore, during the process of "bridging formation → bridging-breaking device activation → bridging disappearance," the sludge output speed at the transfer silo outlet experiences significant fluctuations, causing large fluctuations in the sludge input speed at the hopper, which can easily lead to hopper overloading and overflow. To prevent hopper overflow, this invention also includes a method for automatically adjusting the speed of the transfer conveyor belt, further improving the intelligence of the control.

[0023] Please see Figure 1 , Figure 1 This is a schematic diagram of the sludge transport and drying device of the present invention. The sludge transport and drying device of the present invention includes a transfer device 1, a dryer 2, and a controller 3. Sludge with high moisture content enters the dryer 2 through the transfer device 1 and is transformed into sludge with lower moisture content. The controller 3 controls the transfer device 1.

[0024] Please see Figure 2 , Figure 2This is a schematic diagram of the sludge transport and drying device of the present invention. The transfer device 1 includes a transfer hopper 11, a transfer conveyor belt 12, and a bridging device 13. The transfer hopper 11 is funnel-shaped with a larger top inlet and a smaller bottom outlet. The sludge enters the transfer hopper 11 from the top inlet and falls onto the transfer conveyor belt 12 from the bottom outlet. The transfer conveyor belt 12 transports the sludge to the dryer 2. The bridging device 13 is located at the bottom outlet of the transfer hopper 11 and is used to break up bridging phenomena caused by sludge formation.

[0025] Specifically, the transfer silo 11 is also equipped with a first level sensor (not shown) for detecting the sludge level in the transfer silo 11 and transmitting the detected first level data to the controller 3.

[0026] Specifically, it also includes a feeding motor 121 that provides power to the transfer conveyor belt 12; the feeding motor 121 is connected to the controller 3; the controller 3 controls the start, stop and speed of the transfer conveyor belt 12 by controlling the rotation of the feeding motor 121.

[0027] Specifically, the bridge-breaking device 13 includes a bridge-breaking motor 131 connected to the controller 3 and several rakes 132. The rakes 132 are fixed to the rotating shaft of the bridge-breaking motor 131. When the bridge-breaking device 13 is started, the bridge-breaking motor 131 rotates, driving the rakes 132 to rotate. The rotating rakes 132 agitate the sludge in the transfer silo 11 through their teeth, thereby achieving the bridge-breaking effect. The controller 3 controls the start / stop and agitation speed of the rakes 132 by controlling the rotation of the bridge-breaking motor 131, that is, controls the start / stop and speed of the bridge-breaking device 13.

[0028] The dryer 2 includes a hopper 21, a granulator 22, and a drying conveyor belt 23. The hopper 21 is also funnel-shaped with a larger top inlet and a smaller bottom outlet; its bottom outlet is fixedly connected to the inlet of the granulator 22; the sludge enters the hopper 21 from the top inlet and then enters the granulator 22 from the bottom outlet. The granulator 22 transforms the sludge from lumpy mud into granules, and then conveys the granular sludge to the drying conveyor belt 23 for drying treatment, transforming it into sludge with lower moisture content.

[0029] Specifically, the hopper 21 is also equipped with a second level sensor (not shown) for detecting the sludge level in the hopper 21 and transmitting the detected second level data to the controller 3. Under normal circumstances (when no bridging occurs), the controller controls the rotational speed of the feeding motor based on the second level data. Specifically, the rotational speed of the feeding motor is negatively correlated with the second level data; that is, the higher the second level data, the lower the rotational speed of the feeding motor. In this embodiment, the level sensor is a rotary rheostat level gauge. In other embodiments, the level sensor can be an ultrasonic level gauge, a radar level gauge, an infrared level gauge, or a weighing level gauge, etc. In this embodiment, the rotary rheostat level gauge is installed at the bottom outlet of the transfer silo. If sludge falls, the falling sludge will push the rake of the rotary rheostat level gauge, generating resistance. Therefore, the rotary rheostat level gauge can detect whether sludge is falling at the bottom outlet of the transfer silo based on the resistance. In other embodiments, other types of level gauges can also be used to detect whether sludge is falling at the bottom outlet of the transfer silo by measuring the rate of descent of the first level data.

[0030] Please see Figure 3 , Figure 3 This is a flowchart illustrating the process by which the controller determines whether bridging has occurred. The controller 3 determines whether bridging has occurred in the transfer hopper 11 based on the first material level data. If the controller 3 determines that bridging has occurred in the transfer hopper 11, the controller 3 starts the bridging-breaking motor 131 and controls its speed according to the first material level data, while simultaneously adjusting the speed of the feeding motor 121 according to the second material level data. When the controller 3 determines that the bridging has disappeared, it stops the bridging motor 131 and restores the speed of the feeding motor 121.

[0031] Furthermore, when the controller 3 determines that the bridging phenomenon has disappeared, it delays for a period of time before stopping the bridging device 13. In this embodiment, when the controller 3 determines that the bridging phenomenon has disappeared, it delays for 2 minutes before stopping the bridging device 13.

[0032] Furthermore, to prevent repeated bridging and the resulting risk of damage from frequent start-stop of the bridging device, the controller 3, upon detecting a bridging event, starts the bridging motor 131 and controls its speed according to the first material level data, while simultaneously adjusting the speed of the feeding motor 121 according to the second material level data. Then, it checks every 2 minutes whether the bridging event has disappeared. If the bridging event has disappeared for 5-7 consecutive cycles, the controller stops the bridging motor 131 and restores the speed of the feeding motor 121; otherwise, it continuously increases the speed of the bridging motor 131 until it reaches the set first maximum speed value.

[0033] Furthermore, the controller 3 determines whether bridging has occurred in the transfer silo 11 based on the first material level data. Specifically, the controller 3 determines that bridging has occurred when the first material level data is higher than 50% of the capacity of the transfer silo 11 or when no sludge is detected falling at the bottom outlet of the transfer silo 11; and determines that bridging has disappeared when the first material level data is lower than 50% of the capacity of the transfer silo 11 and sludge is detected falling at the bottom outlet of the transfer silo 11.

[0034] Further, the controller 3 controls the rotational speed of the bridge-breaking motor 131 based on the first material level data, specifically including: the rotational speed of the bridge-breaking motor 131 is positively correlated with the first material level data. In one embodiment, the rotational speed of the bridge-breaking motor 131 is linearly correlated with the magnitude of the first material level data; when the first material level data is 50%, the rotational speed of the bridge-breaking motor 131 is the initial rotational speed of the motor; when the first material level data is 90% of the capacity of the transfer hopper 11, the rotational speed of the bridge-breaking motor 131 is the set first maximum rotational speed.

[0035] Furthermore, when the controller 3 determines that bridging has occurred, it adjusts the speed of the feeding motor 121 according to the second material level data. Specifically, this includes: determining whether the second material level data is higher than 70% of the hopper capacity; if so, making the speed of the feeding motor 121 negatively correlated with the second material level data; if not, recording the original speed of the feeding motor 121, subtracting a fixed value from the original speed to obtain a new speed; and using the new speed as the new speed of the feeding motor 121.

[0036] In one embodiment, the rotational speed of the feeding motor 121 is negatively correlated with the second material level data, specifically: the rotational speed of the feeding motor 121 is linearly negatively correlated with the second material level data; when the second material level data is 0, the rotational speed of the feeding motor 121 is the set second maximum rotational speed; when the second material level data is 90% of the capacity of the hopper 21, the rotational speed of the feeding motor 121 is 0.

[0037] In another embodiment, the rotational speed of the feeding motor 121 is negatively correlated with the second material level data. Specifically, when the second material level data is lower than 50% of the hopper capacity, the controller 3 gradually increases the rotational speed of the feeding motor 121 within a preset time to increase the feeding speed of the transfer conveyor belt 12; after the preset time ends, the rotational speed of the feeding motor 121 remains unchanged; when the second material level data is higher than 50% but lower than 90% of the hopper capacity, the rotational speed of the feeding motor 121 remains unchanged; when the second material level data is higher than 90% of the hopper capacity, the feeding motor 121 stops; simultaneously, an emergency stop and alarm mechanism are triggered. Further, in this embodiment, when the second material level data is lower than 50% of the hopper capacity, the controller 3 gradually increases the rotational speed of the feeding motor 121 within a preset time; the smaller the second material level data, the greater the increase in the rotational speed of the feeding motor per unit time. When the controller detects that the second material level data is between 50% and 60% of the hopper capacity, it keeps the speed of the feeding motor constant. When the controller detects that the second material level data is between 60% and 90% of the hopper capacity, it gradually reduces the speed of the feeding motor. The larger the second material level data, the greater the reduction in the speed of the feeding motor per unit time.

[0038] The controller controls the speed of the feeding motor based on the second material level data under normal circumstances (when no bridging occurs); specifically, the speed of the feeding motor is negatively correlated with the second material level data. This is because a higher second material level data indicates a higher material level in the hopper 21, increasing the risk of sludge overflow. Lowering the speed of the feeding motor 121 when the material level in the hopper 21 is high reduces the amount of sludge entering the hopper 21 per unit time. Since the granulator 22 processes sludge at a stable speed, the material level in the hopper 21 tends to decrease. A higher second material level data results in a lower speed of the feeding motor 121, creating negative feedback regulation that stabilizes the material level in the hopper 21, significantly reducing the probability of sludge overflow.

[0039] The reason for simultaneously reducing the speed of the feeding motor 121 by a fixed value while starting the bridge-breaking motor 131, provided the second material level is not higher than 70% of the hopper capacity, is twofold. Firstly, when the bridge-breaking motor 131 is started, the sludge falling speed suddenly increases. When this sludge reaches the hopper 21 during the bridge-breaking process, the material level in the hopper 21 suddenly rises, potentially causing overflow. Reducing the speed of the feeding motor 121 slows the speed of the transfer conveyor belt 12, decreasing the amount of sludge input to the hopper 21 per unit time. Since the granulator 22 consumes sludge at a stable rate, the material level in the hopper 21 decreases during this period of reduced feeding motor speed. By the time the sludge from the bridge-breaking process reaches the hopper 21, the material level has already dropped to a relatively low level, significantly reducing the probability of overflow. On the other hand, reducing the speed of the feeding motor 121 can also reduce the burden on the transfer hopper and reduce energy consumption. When the second material level is higher than 70% of the hopper capacity, the speed of the feeding motor is already relatively low, possibly lower than the set fixed value. Therefore, even if the bridge breaking device is started, the controller will still maintain the normal control mode for the feeding motor.

[0040] When the material level in the transfer silo 11 is too high, activating the bridging device 13 may cause overload of the bridging device. Activating the bridging device as early as possible can effectively prevent the material level in the transfer silo from becoming too high. Therefore, when the first material level is detected to be higher than 50% of the capacity of the transfer silo 11, the bridging device 13 is activated regardless of whether there is sludge falling at the bottom outlet of the transfer silo 11. When the first material level is lower than 50% of the capacity of the transfer silo 11 and sludge is detected falling at the bottom outlet of the transfer silo 11, it is determined that the bridging phenomenon has disappeared, and the bridging device 13 is stopped.

[0041] This invention automatically detects whether sludge bridging has occurred by installing a first level sensor at the transfer silo and a second level sensor at the hopper, thereby automatically triggering a bridging-breaking device. Compared to existing bridging control methods, this is more convenient and intelligent, saving labor costs. Furthermore, this invention considers the changes in hopper level caused by activating the bridging-breaking device and designs a method for automatically adjusting the speed of the transfer conveyor belt, further improving the intelligence of the control.

[0042] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and the present invention also intends to include these modifications and variations.

Claims

1. A sludge transport and drying device, comprising a transfer unit and a dryer; the transfer unit includes a transfer hopper, a transfer conveyor belt, and a bridging device; sludge falls from the transfer hopper onto the transfer conveyor belt; the transfer conveyor belt transports the sludge to the dryer; the bridging device is disposed above the bottom outlet of the transfer hopper and is used to break up bridging when sludge forms bridging phenomena; characterized in that: It includes a first level sensor and a controller; the first level sensor detects the sludge level in the transfer silo and transmits the detected first level data to the controller. The controller determines whether bridging has occurred in the transfer silo based on the first material level data. Specifically, the controller determines that bridging has occurred when the first material level data is higher than 50% of the transfer silo's capacity or when no sludge is detected falling from the bottom outlet of the transfer silo; the controller determines that bridging has disappeared when the first material level data is lower than 50% of the transfer silo's capacity and sludge is detected falling from the bottom outlet of the transfer silo; if bridging occurs, the controller activates a bridging breaking device. The bridge breaking device includes a bridge breaking motor and several rakes connected to the controller. When the bridge breaking device is started, the bridge breaking motor rotates, which drives the rakes to rotate. The rotating rakes agitate the sludge in the transfer silo, thereby breaking the bridge. When the controller determines that a bridging phenomenon has occurred, it controls the speed of the bridge breaking motor according to the first material level data. The transfer device also includes a feeding motor connected to the controller; the feeding motor controls the start, stop and speed of the transfer conveyor belt; the dryer also includes a hopper and a granulator; the transfer conveyor belt transports sludge to the top inlet of the hopper; the sludge enters the hopper from the top inlet and then enters the granulator from the bottom outlet of the hopper; The sludge transport and drying device further includes a second level sensor; the second level sensor detects the sludge level in the hopper and transmits the detected second level data to the controller; the controller adjusts the speed of the feeding motor according to the second level data, specifically including: the speed of the feeding motor is negatively correlated with the second level data; When the controller determines that bridging has occurred and the second material level data is not higher than 70% of the hopper capacity, it reduces the speed of the feeding motor. Specifically, this includes: recording the original speed of the feeding motor, subtracting a fixed value from the original speed to obtain a new speed, and using the new speed as the new speed of the feeding motor.

2. The sludge transport and drying device according to claim 1, characterized in that: When the controller determines that bridging has occurred, it controls the speed of the bridging motor according to the first material level data. Specifically, the speed of the bridging motor is linearly positively correlated with the magnitude of the first material level data; when the first material level data is 50%, the speed of the bridging motor is the initial speed of the motor; when the first material level data is 90% of the capacity of the transfer hopper, the speed of the bridging motor is the set first maximum speed value.

3. The sludge transport and drying device according to claim 2, characterized in that: The rotational speed of the feeding motor is negatively correlated with the second material level data, specifically: the rotational speed of the feeding motor is linearly negatively correlated with the second material level data; when the second material level data is 0, the rotational speed of the feeding motor is the set second maximum rotational speed; when the second material level data is 90% of the hopper capacity, the rotational speed of the feeding motor is 0.

4. The sludge transport and drying device according to claim 3, characterized in that: When the controller determines that bridging has occurred, it starts the bridging motor and controls the speed of the bridging motor according to the first material level data, while adjusting the speed of the feeding motor according to the second material level data; then it checks whether the bridging has disappeared every 2 minutes; if the bridging has disappeared for 5 to 7 consecutive cycles, it stops the bridging motor and restores the speed of the feeding motor. Otherwise, the speed of the bridge-breaking motor will be continuously increased until the speed of the bridge-breaking motor reaches the set first maximum speed value.

5. A sludge belt dryer, characterized in that: Includes the sludge transport and drying apparatus according to any one of claims 1-4.

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