Method and system for controlling low-carbon incineration of organic sludge

Abstract

The invention discloses a control method and system for low-carbon incineration of organic sludge. The control method comprises the following steps that firstly, wet sludge is pumped; step 2, conveying of dry sludge: transversely conveying the dry sludge separated by the plate-and-frame filter press to an elevator through a transverse screw conveyor, upwards lifting the dried sludge to a sludge incinerator through the elevator, and temporarily storing the separated sewage through a storage tank; thirdly, sludge incineration is conducted, specifically, according to the input amount of the sludge, the fuel pumping amount and the combustion-supporting gas pumping amount of the sludge incinerator are adjusted, excessive fuel and combustion-supporting gas are prevented from being input, and waste gas is reduced; step 4, cooling and dust removal of the waste smoke: after the waste gas enters a spray tower, pumping the sewage separated in the step 1 by a water pump of the spray tower, reducing the exhaust temperature after the waste gas is in contact with the sewage, and capturing particulate matters in the waste gas by the sewage; waste smoke utilization circulation can be constructed, the sludge drying efficiency is improved, and more energy is saved in incineration.

Description

Technical Field

[0001] The invention relates to a control method and system for low-carbon incineration of organic sludge. Background Art

[0002] In recent years, domestic urban sewage treatment facilities have been continuously built and upgraded, and the output of sludge as a by-product of sewage treatment has also been increasing. Incineration is a thermal treatment method that uses an incinerator to completely decompose sludge into a small amount of ash under high temperature conditions. It is an efficient and fast treatment method that is completely harmless, minimizes the amount of sludge, and generates waste heat that can be used as a resource.

[0003] In the prior art, sludge is directly incinerated in an incinerator after being dehydrated. During the incineration process, a large amount of waste smoke is generated and a large amount of fuel is consumed. The heat of this part of the waste smoke is wasted, the fuel input control is poor, and the utilization rate is not high.

[0004] Based on the above problems, we have designed a control method and system for low-carbon incineration of organic sludge that can build a waste smoke utilization cycle, improve sludge drying efficiency, and make incineration more energy-saving. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a control method and system for low-carbon incineration of organic sludge which can construct a waste smoke utilization cycle, improve sludge drying efficiency, and make incineration more energy-saving.

[0006] To solve the above problems, the present invention adopts the following technical solutions:

[0007] A control method for low-carbon incineration of organic sludge comprises the following steps:

[0008] Step 1: Pumping of wet sludge: Pumping the sludge in the sludge pool with a sludge pump and pumping the sludge into a plate and frame filter press for separation of sludge and sewage;

[0009] Step 2: Transportation of dry sludge: The dry sludge separated by the plate and frame filter press is transported to the elevator horizontally through a horizontal screw conveyor. The elevator lifts the dried sludge upward to the sludge incinerator, and the separated sewage is temporarily stored in a storage tank;

[0010] Step 3, sludge incineration: According to the input amount of sludge, adjust the fuel pumping amount and combustion-supporting gas pumping amount of the sludge incinerator to avoid inputting too much fuel and combustion-supporting gas to reduce the generation of waste gas. The waste smoke generated by incineration is transported to the heat exchanger, and the heat exchanger heats the pipeline of the horizontal conveyor to further evaporate the water in the sludge passing through the horizontal conveyor. The waste gas enters the spray tower after heating the heat exchanger. In this process, the waste gas temperature is reduced, reducing the harm to the atmosphere and reducing the pressure of the later spray treatment;

[0011] Step 4: Cooling and dust removal of waste smoke: After the waste gas enters the spray tower, the water pump of the spray tower extracts the sewage separated in step 1. The exhaust temperature is reduced after the waste gas contacts the sewage, and the sewage captures the particulate matter in the waste gas. When the sewage is insufficient, the water pump extracts clean water to supplement it to ensure that the exhaust temperature is within 55 degrees Celsius.

[0012] Preferably, in step one, the pumping of the wet sludge maintains a uniform pumping flow rate, and the pumping volume needs to be less than 80% of the maximum filtration capacity of the plate and frame filter press. When the plate and frame filter press is extruding and separating, the sludge pump is kept closed. After the separation of the plate and frame filter press is completed and the sewage is discharged, the sludge pump is turned on to start pumping the sludge for the next treatment. After the sewage is separated from the plate and frame filter press, it is sent to a storage tank for temporary storage, which is convenient for the water pump of the spray tower in step four to extract it, and the sludge is transported to the elevator.

[0013] Preferably, the transverse conveyor passes through the material trough of the plate and frame filter press, so that the separated and fallen dry sludge can be directly obtained by the transverse conveyor. The step where the transverse conveyor extends to the outside of the plate and frame filter press is assembled with a heat exchanger, so that the waste smoke generated by the sludge incinerator burning the sludge acts on the transverse conveyor, and the sludge after extrusion and drying is further dried at high temperature. In this process, the temperature of the waste gas entering the spray tower is reduced, which makes the sludge incineration easier and reduces the consumption of fuel and combustion-supporting gas.

[0014] Preferably, a first temperature sensor is installed at the waste smoke emission position of the sludge incinerator to monitor the exhaust temperature of the sludge incinerator. When the exhaust temperature is higher than 250 degrees Celsius, the fuel pumping rate and the combustion-supporting gas pumping rate of the sludge incinerator are reduced, and the input amount of dry sludge is reduced until the waste smoke temperature of the sludge incinerator is reduced to below 250 degrees Celsius. When the exhaust temperature monitored by the first temperature sensor is lower than 150 degrees Celsius, it is necessary to increase the fuel pumping rate and the combustion-supporting gas pumping rate so that the exhaust temperature is maintained at 150-250 degrees Celsius.

[0015] Preferably, a second temperature sensor is installed at the smoke outlet position of the heat exchanger. The second temperature sensor is used to monitor the temperature of the waste smoke after passing through the heat exchanger. The temperature of the waste smoke after passing through the heat exchanger needs to be 50 to 80 degrees Celsius lower than the smoke outlet temperature of the sludge incinerator. When the waste smoke temperature detected by the second temperature sensor and the smoke outlet temperature of the sludge incinerator monitored by the first temperature sensor are less than 30 degrees Celsius, that is, the surface of the transverse conveyor is covered with excessive dirt thickness caused by the waste smoke particles, affecting the heat exchange. At this time, the heat exchanger and the transverse conveyor need to be cleaned.

[0016] Preferably, a third temperature sensor is installed at the outlet position of the spray tower, and the outlet temperature of the spray tower is monitored by the third temperature sensor. When the outlet temperature is higher than 55 degrees Celsius, it is necessary to increase the amount of water pumped in so that the water is fully in contact with the exhaust smoke, capture particulate matter, and reduce the exhaust temperature to reduce thermal pollution to the air. When the outlet temperature cannot be reduced to less than 55 degrees Celsius after increasing the amount of water pumped in, check whether the first temperature sensor is working properly. If the first temperature sensor is working properly and the exhaust temperature of the sludge incinerator is between 150 degrees Celsius and 250 degrees Celsius, reduce the fuel pumping amount by 10% to 15%, reduce the combustion-supporting gas input by 20% to 25%, and then reduce the heat of mixed combustion, so that the outlet temperature at the spray tower is reduced to less than 55 degrees Celsius. When the first temperature sensor fails, the monitored exhaust temperature is inaccurate. At this time, check whether the temperature index of the second temperature sensor is normal. If the exhaust temperature is normal, it is determined that the second temperature sensor is also faulty, and the first temperature sensor and the second temperature sensor need to be replaced together.

[0017] Preferably, a high temperature resistant fan is installed between the sludge incinerator and the heat exchanger to increase the ventilation volume.

[0018] A system for low-carbon incineration of organic sludge comprises the control method.

[0019] The beneficial effects of the present invention are:

[0020] Through the control method and system, the high-temperature waste smoke generated during the incineration process of the sludge incinerator can be used to dry the sludge that has been squeezed by the plate and frame filter press, further improving the dehydration rate, so that the sludge can be quickly incinerated after entering the sludge incinerator, reducing the heat consumption of evaporating water, saving the fuel consumption of the sludge incinerator, and reducing the incineration cost. After the waste smoke is heat exchanged through the heat exchanger, its temperature is reduced. After entering the spray tower, the steam volume can be reduced, and the evaporation of water for spraying dust reduction can be reduced. Secondly, the waste water after the sludge is dehydrated can be used for spraying dust reduction. In summary, the final exhaust temperature is reduced, reducing the damage to the atmosphere, which is suitable for promotion and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a system diagram of the present invention. DETAILED DESCRIPTION

[0023] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0024] Any feature disclosed in this specification (including any additional claims, abstract and drawings), unless otherwise stated, may be replaced by other equivalent or alternative features with similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0025] In the description of the present invention, it is necessary to understand that the terms "one end", "the other end", "outside", "upper", "inside", "horizontal", "coaxial", "center", "end", "length", "outer end" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0026] In addition, in the description of the present invention, “plurality” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0027] In the present invention, unless otherwise clearly specified and limited, the terms "disposed", "socketed", "connected", "through", "plugged" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] See also Figure 1 A control method for low-carbon incineration of organic sludge is shown, comprising the following steps:

[0029] Step 1: Pumping wet sludge: Pumping sludge from the sludge pool 2 through the sludge pump 1, and pumping the sludge into the plate and frame filter press 3 to separate the sludge and sewage;

[0030] Step 2: Transportation of dry sludge: The dry sludge separated by the plate and frame filter press 3 is transported to the elevator 5 through the horizontal conveyor 4, and the dried sludge is lifted upward to the sludge incinerator 6 by the elevator 5, and the separated sewage is temporarily stored in the storage tank 7;

[0031] Step 3, sludge incineration: according to the input amount of sludge, adjust the fuel pumping amount and combustion-supporting gas pumping amount of the sludge incinerator 6 to avoid inputting too much fuel and combustion-supporting gas to reduce the generation of waste gas. The waste smoke generated by the incineration is transported to the heat exchanger 8. The heat exchanger 8 heats the pipeline of the horizontal conveyor 4, so that the water in the sludge passing through the horizontal conveyor 4 is further evaporated. After heating the heat exchanger 8, the waste gas enters the spray tower 9. In this process, the waste gas temperature is reduced, reducing the harm to the atmosphere and reducing the pressure of the later spray treatment;

[0032] Step 4: Cooling and dust removal of waste smoke: After the waste gas enters the spray tower 9, the water pump 10 of the spray tower 9 extracts the sewage separated in step 1. The exhaust temperature is reduced after the waste gas contacts the sewage, and the sewage captures the particulate matter in the waste gas. When the sewage is insufficient, the water pump 10 extracts clean water for supplementation to ensure that the exhaust temperature is within 55 degrees Celsius.

[0033] In the above technical solution, the water separated from the sludge is used for later spraying, which can achieve the purpose of water saving, and the particulate matter in the exhaust smoke can be captured after spraying to achieve the purpose of dust reduction.

[0034] The waste smoke generated by the sludge incinerator during the incineration process can heat the heat exchanger, thereby further drying the dried sludge transported by the transverse conveyor 4, so that the water content of the dry sludge is less than 1% when it enters the sludge incinerator, making it easier to burn into powder, consuming less energy for combustion, and generating less waste smoke.

[0035] After heat exchange through the heat exchanger, the temperature of the waste smoke is reduced. After entering the spray tower, the amount of water evaporated from the cooled waste smoke is reduced, reducing the water required for cooling the waste smoke. At the same time, sewage and clean water are used for dust reduction. The first is to consume the water removed from the sludge, and the second is to use sewage to capture particulate matter.

[0036] The sewage captures the particulate matter in the exhaust smoke and then settles. The settled water enters the sedimentation process to form new sludge. This part of the sludge can re-enter the plate and frame filter press and then repeat the operation to reduce the generation of secondary waste.

[0037] In a preferred embodiment of the present invention, in step one, the pumping of the wet sludge maintains a uniform pumping flow rate, and the pumping volume needs to be less than 80% of the maximum filtration capacity of the plate and frame filter press. When the plate and frame filter press is extruding and separating, the sludge pump is kept closed. After the plate and frame filter press is separated and the sewage is discharged, the sludge pump is turned on to start pumping the sludge for the next treatment. After the sewage is separated from the plate and frame filter press, it is sent to a storage tank for temporary storage, which is convenient for the water pump of the spray tower in step four to extract it, and the sludge is transported to the elevator.

[0038] The amount of wet sludge entering needs to be significantly smaller than the processing capacity of the plate and frame filter press to avoid damage to the plate and frame filter press due to overload.

[0039] Adjust the amount of fuel and combustion-supporting gas used in the sludge incinerator according to the pumping volume of the sludge pump per unit time. Reduce the amount of fuel and combustion-supporting gas used as much as possible while meeting the incineration requirements.

[0040] This will reduce the cost of sludge incineration.

[0041] See also Figure 1 As shown, the transverse conveyor 4 passes through the material trough 31 of the plate and frame filter press 3, so that the separated and fallen dry sludge is directly obtained by the transverse conveyor 4, and the step where the transverse conveyor 4 extends to the outside of the plate and frame filter press 3 is assembled with the heat exchanger 8, so that the waste smoke generated by the sludge incineration furnace burning the sludge acts on the transverse conveyor 4, and the sludge after extrusion and drying is further dried at high temperature. In this process, the temperature of the waste gas entering the spray tower 9 is reduced, which makes the sludge incineration easier and reduces the consumption of fuel and combustion-supporting gas.

[0042] This technical means is to combine the transverse conveyor 4 with the plate and frame filter press 3, so that after the sewage is separated, the bottom of the material trough 31 is opened. After opening, the sludge received by the material trough 31 falls directly into the transverse conveyor 4, eliminating the step of manual transfer.

[0043] The bottom of the trough 31 adopts a flap structure and is in a closed state under normal circumstances. When the plate and frame filter press is used for extrusion and dehydration, it first receives the sewage, which is then directed to a storage tank for storage. After the sewage is discharged, the plate and frame filter press is opened to allow the dehydrated sludge to fall into the trough 31, and then the bottom flap structure of the trough 31 is opened to allow the sludge to fall into the transverse conveyor 4.

[0044] The above technology can realize automatic operation and eliminate the manual operation steps.

[0045] See also Figure 1 As shown, a first temperature sensor 61 is installed at the waste smoke emission position of the sludge incinerator 6 to monitor the exhaust temperature of the sludge incinerator. When the exhaust temperature is higher than 250 degrees Celsius, the fuel pumping rate and the combustion-supporting gas pumping rate of the sludge incinerator are reduced, and the input amount of dry sludge is reduced until the waste smoke temperature of the sludge incinerator is reduced to below 250 degrees Celsius. When the exhaust temperature monitored by the first temperature sensor is lower than 150 degrees Celsius, it is necessary to increase the fuel pumping rate and the combustion-supporting gas pumping rate so that the exhaust temperature is maintained at 150-250 degrees Celsius.

[0046] See also Figure 1As shown, a second temperature sensor 81 is installed at the smoke outlet position of the heat exchanger 8. The second temperature sensor 81 is used to monitor the temperature of the waste smoke after passing through the heat exchanger. The temperature of the waste smoke after passing through the heat exchanger needs to be 50 to 80 degrees Celsius lower than the smoke outlet temperature of the sludge incinerator. When the difference between the waste smoke temperature detected by the second temperature sensor and the smoke outlet temperature of the sludge incinerator monitored by the first temperature sensor is less than 30 degrees Celsius, that is, the thickness of the dirt generated by the waste smoke particles fixed on the surface of the transverse conveyor is too large, affecting the heat exchange. At this time, the heat exchanger and the transverse conveyor need to be cleaned.

[0047] See also Figure 1 As shown, a third temperature sensor 91 is installed at the outlet position of the spray tower 9, and the outlet temperature of the spray tower is monitored by the third temperature sensor. When the outlet temperature is higher than 55 degrees Celsius, it is necessary to increase the amount of water pumped in so that the water is fully in contact with the exhaust smoke, capture particulate matter, and reduce the exhaust temperature to reduce thermal pollution to the air. When the outlet temperature cannot be reduced to less than 55 degrees Celsius after increasing the amount of water pumped in, check whether the first temperature sensor is working properly. If the first temperature sensor is working properly and the exhaust temperature of the sludge incinerator is between 150 degrees Celsius and 250 degrees Celsius, reduce the fuel pumping amount by 10-15%, reduce the combustion-supporting gas input by 20%, and then reduce the heat of mixed combustion, so that the outlet temperature at the spray tower is reduced to less than 55 degrees Celsius; when the first temperature sensor fails, the monitored exhaust temperature is inaccurate. At this time, check whether the temperature index of the second temperature sensor is normal. If it is prompted that the exhaust temperature is normal, it is determined that the second temperature sensor is also faulty, and the first temperature sensor and the second temperature sensor need to be replaced together.

[0048] See also Figure 1 As shown, a high temperature resistant fan 11 is installed between the sludge incinerator and the heat exchanger, and the ventilation volume is increased by the fan 11.

[0049] The fan 11 is a centrifugal fan, and the motor is an external motor to avoid overheating of the motor caused by high temperature. The fan 11 can increase the ventilation volume and avoid smoke leakage.

[0050] A system for low-carbon incineration of organic sludge comprises the control method.

[0051] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A control method for low-carbon incineration of organic sludge, characterized in that: The following steps are involved: Step 1: Pumping of wet sludge: Pumping the sludge in the sludge pool with a sludge pump and pumping the sludge into a plate and frame filter press for separation of sludge and sewage; Step 2: Transportation of dry sludge: The dry sludge separated by the plate and frame filter press is transported to the elevator horizontally through a horizontal screw conveyor. The elevator lifts the dried sludge upward to the sludge incinerator, and the separated sewage is temporarily stored in a storage tank; Step 3, sludge incineration: According to the input amount of sludge, adjust the fuel pumping amount and combustion-supporting gas pumping amount of the sludge incinerator to avoid inputting too much fuel and combustion-supporting gas to reduce the generation of waste gas. The waste smoke generated by incineration is transported to the heat exchanger, and the heat exchanger heats the pipeline of the horizontal conveyor to further evaporate the water in the sludge passing through the horizontal conveyor. The waste gas enters the spray tower after heating the heat exchanger. In this process, the waste gas temperature is reduced, reducing the harm to the atmosphere and reducing the pressure of the later spray treatment; Step 4: Cooling and dust removal of waste smoke: After the waste gas enters the spray tower, the water pump of the spray tower extracts the sewage separated in step 1. The exhaust temperature is reduced after the waste gas contacts the sewage, and the sewage captures the particulate matter in the waste gas. When the sewage is insufficient, the water pump extracts clean water to supplement it to ensure that the exhaust temperature is within 55 degrees Celsius.

2. The control method for low-carbon incineration of organic sludge according to claim 1 is characterized in that: In step one, the pumping of the wet sludge maintains a uniform pumping flow rate, and the pumping volume needs to be less than 80% of the maximum filtration capacity of the plate and frame filter press. When the plate and frame filter press is extruding and separating, the sludge pump is kept closed. After the plate and frame filter press is separated and the sewage is discharged, the sludge pump is turned on to start pumping the next sludge for treatment. After the sewage is separated from the plate and frame filter press, it is sent to a storage tank for temporary storage to facilitate the extraction by the water pump of the spray tower in step four, and the sludge is transported to the elevator.

3. The control method for low-carbon incineration of organic sludge according to claim 1 is characterized in that: The transverse conveyor passes through the material trough of the plate and frame filter press, so that the separated dry sludge can be directly obtained by the transverse conveyor. The step where the transverse conveyor extends to the outside of the plate and frame filter press is assembled with a heat exchanger, so that the waste smoke generated by the sludge incinerator burning the sludge acts on the transverse conveyor, and the sludge after extrusion and drying is further dried at high temperature. In this process, the temperature of the waste gas entering the spray tower is reduced, which makes the sludge incineration easier and reduces the consumption of fuel and combustion-supporting gas.

4. The control method for low-carbon incineration of organic sludge according to claim 1 is characterized in that: A first temperature sensor is installed at the waste smoke emission position of the sludge incinerator to monitor the exhaust temperature of the sludge incinerator. When the exhaust temperature is higher than 250 degrees Celsius, the fuel pumping rate and the combustion-supporting gas pumping rate of the sludge incinerator are reduced, and the input amount of dry sludge is reduced until the waste smoke temperature of the sludge incinerator is reduced to below 250 degrees Celsius. When the exhaust temperature monitored by the first temperature sensor is lower than 150 degrees Celsius, it is necessary to increase the fuel pumping rate and the combustion-supporting gas pumping rate so that the exhaust temperature is maintained at 150-250 degrees Celsius.

5. The control method for low-carbon incineration of organic sludge according to claim 4 is characterized in that: A second temperature sensor is installed at the smoke outlet position of the heat exchanger. The second temperature sensor is used to monitor the temperature of the waste smoke after passing through the heat exchanger. The temperature of the waste smoke after passing through the heat exchanger needs to be 50 to 80 degrees Celsius lower than the smoke outlet temperature of the sludge incinerator. When the difference between the waste smoke temperature detected by the second temperature sensor and the smoke outlet temperature of the sludge incinerator monitored by the first temperature sensor is less than 30 degrees Celsius, that is, the surface of the transverse conveyor is covered with excessive dirt thickness caused by the waste smoke particles, affecting the heat exchange. At this time, the heat exchanger and the transverse conveyor need to be cleaned.

6. The method for controlling low-carbon incineration of organic sludge according to claim 5, characterized in that: A third temperature sensor is installed at the outlet position of the spray tower, and the outlet temperature of the spray tower is monitored by the third temperature sensor. When the outlet temperature is higher than 55 degrees Celsius, it is necessary to increase the amount of water pumped in so that the water is fully in contact with the waste smoke, capture particulate matter, and reduce the exhaust temperature to reduce thermal pollution to the air. When the outlet temperature cannot be reduced to less than 55 degrees Celsius after increasing the amount of water pumped in, check whether the first temperature sensor is working properly. If the first temperature sensor is working properly and the exhaust temperature of the sludge incinerator is between 150 degrees Celsius and 250 degrees Celsius, reduce the fuel pumping amount by 10% to 15%, reduce the combustion-supporting gas input by 20% to 25%, and then reduce the heat of mixed combustion, so that the outlet temperature at the spray tower is reduced to less than 55 degrees Celsius; when the first temperature sensor fails, the monitored exhaust temperature is inaccurate. At this time, check whether the temperature index of the second temperature sensor is normal. If it is prompted that the exhaust temperature is normal, it is determined that the second temperature sensor is also faulty, and the first temperature sensor and the second temperature sensor need to be replaced together.

7. The method for controlling low-carbon incineration of organic sludge according to claim 1, characterized in that: A high temperature resistant fan is installed between the sludge incinerator and the heat exchanger to increase the ventilation volume.

8. A system for low-carbon incineration of organic sludge, characterized by: The method comprises the control method as claimed in any one of claims 1 to 7.

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