Sludge drying weight reduction method and low-temperature drying box

Abstract

The invention provides a sludge drying weight reduction method and a low-temperature drying box, and the method comprises the following steps: S1, carrying out filter pressing on sludge, and enabling the sludge after filter pressing to enter a sludge hopper; s2, the sludge hopper is conveyed to a low-temperature drying box to be dried; and S3, bagging the sludge dried in the step S2 in a sludge bucket, and transporting the sludge outwards. The system has the beneficial effects that the newly added dehumidification low-temperature drying system does not influence the safe operation of the original sludge treatment system. The dehumidifying and drying system meets the demand for sludge drying, and a design safety margin is reserved. And the particles are dried at low temperature of 70 DEG C or below, the temperature of the particles is lower than 70 DEG C, and dust and explosion danger are avoided. And the discharging temperature is low (less than 50 DEG C), cooling is not needed, and direct storage can be realized.

Description

Technical Field

[0001] The invention belongs to the field of sludge treatment, and in particular relates to a sludge drying and weight reduction method and a low-temperature drying box. Background Art

[0002] A large amount of wastewater is generated during the production process. When treating the wastewater produced, the wastewater treatment station will produce two types of sludge, namely chromium-containing sludge (hereinafter referred to as hazardous waste) and acid-containing sludge (hereinafter referred to as solid waste). About 30 tons of hazardous waste sludge and 600 tons of solid waste sludge are generated every month. The total amount of solid and hazardous waste discharged is large, and the disposal cost is high. In the context of increasingly stringent national environmental protection, it is imperative to reduce the amount of solid and hazardous waste sludge.

[0003] Our wastewater treatment station currently has five plate-frame filter presses that can process sludge (numbered: A, B, C, D, E). The sludge discharge ports of the A, B, and C plate-frame filter presses are located in the 1# mud cake room, and the sludge discharge ports of the D and E plate-frame filter presses are located in the 2# mud cake room. Solid waste is directly discharged from the A, B, D, and E plate-frame filter presses into the open truck compartment below for transportation; hazardous waste is discharged from the C plate-frame filter press into a square transport trough and then transported to a closed van by a forklift for transportation. The sludge to be treated at the wastewater station has been described in detail, such as Figure 5 shown. Invention content

[0004] In view of this, the present invention aims to propose a sludge drying and weight reduction method and a low-temperature drying box to solve at least one technical problem in the background technology.

[0005] To achieve the above object, the technical solution created by the present invention is implemented as follows:

[0006] The sludge drying and weight reduction method and the low-temperature drying box include the following steps:

[0007] S1: The sludge is filtered and the sludge after filtering enters the sludge hopper;

[0008] S2: The sludge hopper is transported to the low-temperature drying box for drying;

[0009] S3: The sludge dried in step S2 is packed into bags for external transportation.

[0010] Furthermore, in step S1, the sludge is filtered by a plate and frame filter press.

[0011] Furthermore, the low-temperature drying box includes a box body and a middle partition, wherein the middle partition is arranged in the box body, and the middle partition divides the box body into a drying area and a condensation heating area;

[0012] There is a gap between the middle partition and the box body, which allows the gas in the drying area of ​​the box to enter the condensation and heating area.

[0013] A drying assembly is provided in the drying area of ​​the box body, and a drying plate for placing a sludge hopper is provided in the drying assembly;

[0014] A heat regenerator component and a condensing heat regenerating component are provided in the condensing heating area of ​​the box;

[0015] A blower is provided in the condensation heating area of ​​the box body, and the gas treated in the condensation heating area is sent to the bottom of the drying plate of the drying assembly through the middle partition by the blower;

[0016] One side of the box is open and is provided with a box door.

[0017] Furthermore, the drying assembly includes a base and a drying shell, the drying shell is arranged above the base, the top of the drying shell is open, and a drying door is installed on one side of the drying shell close to the cabinet door, and the drying door corresponds to the cabinet door;

[0018] The drying plate is fixedly arranged in the drying shell.

[0019] Furthermore, the drying plate is provided with a first air hole capable of allowing air to circulate.

[0020] The sludge is arranged in a sludge hopper, the top of the sludge hopper is open, a bottom plate is arranged at the bottom of the sludge hopper, the bottom plate is detachably connected to the sludge hopper, and a second air hole corresponding to the first air hole is arranged on the bottom plate.

[0021] Furthermore, a pipe hole is provided on the middle partition, the blower is connected to the drying shell through a ventilation pipe, and the ventilation pipe is arranged below the drying plate.

[0022] Further, the regenerator assembly includes a first regenerator and a second regenerator;

[0023] One side of the first heat regenerator is connected to the other side of the second heat regenerator through a heat exchange pipe.

[0024] Further, the condensation heat recovery component includes an evaporator, a dehumidification heating pump device, and a condenser;

[0025] The evaporator is arranged between the first regenerator and the second regenerator;

[0026] The condenser is arranged below the second regenerator, and the upper part of the evaporator is connected to the lower part of the condenser through the first pipe;

[0027] The upper part of the condenser is connected to the evaporator through a second pipe;

[0028] The dehumidification heating pump device is arranged on the first pipeline.

[0029] The gas containing water vapor passes through the first regenerator and exchanges heat with the medium inside the first regenerator. After the heat exchange, the medium of the first regenerator enters the second regenerator and is heated by the gas passing through the evaporator.

[0030] Furthermore, an expansion valve is provided on the second pipeline.

[0031] Furthermore, a condensate tray is provided at the bottom of the evaporator, the condensate tray is arranged on the side wall of the box body, a condensate drain pipe is provided at the bottom of the condensate tray, the condensate drain pipe extends out of the box body, and a water outlet valve is provided on the condensate drain pipe.

[0032] The medium in the evaporator exchanges heat with the wet air. The heated medium in the evaporator enters the dehumidification heating pump equipment and then enters the condenser. The medium in the condenser exchanges heat with the gas passing through the second heat regenerator to heat the gas. The medium in the condenser enters the evaporator through the second pipeline after being cooled to achieve energy recovery.

[0033] The heat pump motor drives the blower to release dry hot air. The dry hot air contacts the sludge and takes away the moisture in the sludge to release humid air. Since the equipment is a closed space, the humid air moves downward and contacts the regenerator for heat exchange. The exchanged humid air contacts the evaporator, and the evaporator absorbs heat to form part of the condensed water, which is discharged to the sewage ditch. Another part of the cold air contacts the regenerator for heat exchange. The exchanged air contacts the condenser, and the condenser releases heat to form hot air, which is then transported to the blower. The heat pump motor then drives the blower to release dry hot air. In this way, a closed hot air cycle is performed to dry the moisture in the sludge.

[0034] Compared with the prior art, the sludge drying and weight reduction method and low-temperature drying box created by the present invention have the following advantages:

[0035] 1. This application is safe: the newly added dehumidification and low-temperature drying system does not affect the safe operation of the original sludge treatment system. The dehumidification and drying system meets the demand for sludge drying and leaves a design safety margin. Low-temperature drying below 70°C, the particle temperature is below 70°C, there is no dust, and there is no explosion hazard. The discharge temperature is low (<50°C), no cooling is required, and it can be stored directly.

[0036] 2. This application is technologically advanced: it adopts advanced dehumidification condensation dehumidification technology with high efficiency and reliable operation. It can directly dry sludge with a moisture content of up to 75% to 20% without the need for segmented disposal. It adopts advanced low-temperature drying and dehumidification technology, without exhaust gas and waste dust discharge. It adopts advanced automatic control technology and centralized equipment monitoring, and can set and adjust the moisture content of the sludge after drying. Online monitoring of the operating status of the dryer and the sludge input status. The drying system is equipped with a reliable monitoring alarm and protection system; and the operating status and alarm information of the sludge conveying equipment are monitored through the touch screen. There is no loss of organic matter in the drying process, and no other ingredients need to be added. The dry material has a high calorific value and is suitable for later resource utilization.

[0037] 3. This application is economical: on the premise of meeting the technical requirements for equipment use, domestic high-quality products are preferred. The initial investment and later operating costs of the equipment are comprehensively considered to minimize the overall cost.

[0038] 4. This application can save energy and protect the environment: it adopts a low-temperature fully enclosed drying mode, no odor overflows, and no complex deodorization equipment needs to be installed. The low-temperature drying process greatly reduces the amount of H2S and NH3 precipitation. The condensed water (sludge moisture) is discharged to the original sewage treatment system, which is simple to handle and saves the cost of condensed water treatment during the drying process. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0040] Figure 1 A schematic diagram of the process of the sludge drying and weight reduction method and the low-temperature drying box according to the embodiment of the present invention;

[0041] Figure 2 A schematic diagram of a low temperature drying box according to an embodiment of the present invention;

[0042] Figure 3 A schematic diagram of a forklift according to an embodiment of the present invention;

[0043] Figure 4 A schematic diagram of the transportation of a forklift according to an embodiment of the present invention;

[0044] Figure 5 This is a table of sludge treatment conditions in wastewater stations using prior art.

[0045] Description of reference numerals:

[0046] 1. Plate and frame filter press; 2. Low-temperature drying box; 3. Transport forklift; 4. Ton bag container; 5. Box body; 6. Middle partition; 7. Blower; 8. Base; 9. Drying shell; 10. Drying plate; 11. First air vent; 12. Ventilation duct; 13. First regenerator; 14. Second regenerator; 15. Evaporator; 16. Dehumidification heating pump equipment; 17. Condenser; 18. Expansion valve; 19. Condensate tray; 20. Condensate drain pipe. DETAILED DESCRIPTION

[0047] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0048] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0049] Example 1

[0050] The sludge drying and weight reduction method and the low-temperature drying box include the following steps: S1: the sludge is filtered, and the sludge after filtering enters the sludge bucket; S2: the sludge bucket is transported to the low-temperature drying box for drying; S3: the sludge bucket after drying in step S2 is bagged and transported out.

[0051] In the step S1, the sludge is filtered by a plate and frame filter press.

[0052] The low-temperature drying box includes a box body and a middle partition. The middle partition is arranged in the box body, and the middle partition divides the box body into a drying area and a condensation heating area. There is a gap between the middle partition and the box body, which allows the gas in the drying area of ​​the box body to enter the condensation heating area. The drying area of ​​the box body has a drying component, and the drying component is provided with a drying plate for placing a sludge hopper; the condensation heating area of ​​the box body has a regenerator component and a condensation heat recovery component; the condensation heating area of ​​the box body has a blower, and the gas treated in the condensation heating area is sent to the bottom of the drying plate of the drying component through the blower through the middle partition; one side of the box body is open, and a box door is installed.

[0053] The drying assembly includes a base and a drying shell. The drying shell is arranged above the base. The top of the drying shell is open. A drying door is installed on the side of the drying shell close to the cabinet door, and the drying door corresponds to the cabinet door. The drying plate is fixedly arranged in the drying shell. A first air hole that can circulate air is arranged on the drying plate. The sludge is arranged in the sludge hopper. The top of the sludge hopper is open. A bottom plate is arranged at the bottom of the sludge hopper. The bottom plate is detachably connected to the sludge hopper. A second air hole corresponding to the first air hole is arranged on the bottom plate. A pipe hole is arranged on the middle partition. The blower is connected to the drying shell through a ventilation duct, and the ventilation duct is arranged below the drying plate.

[0054] The regenerator assembly includes a first regenerator and a second regenerator; one side of the first regenerator and the second regenerator is connected by a heat exchange pipe. The condensation regenerator assembly includes an evaporator, a dehumidification heating pump device, and a condenser; the evaporator is arranged between the first regenerator and the second regenerator; the condenser is arranged below the second regenerator, and the upper part of the evaporator is connected to the lower part of the condenser through the first pipe; the upper part of the condenser is connected to the evaporator through the second pipe; the dehumidification heating pump device is arranged on the first pipe. The gas containing water vapor passes through the first regenerator and exchanges heat with the medium inside the first regenerator. After the heat exchange, the medium of the first regenerator enters the second regenerator, and the gas passing through the evaporator is heated.

[0055] The second pipeline is provided with an expansion valve. A condensate tray is provided at the bottom of the evaporator, the condensate tray is arranged on the side wall of the box body, a condensate drain pipe is provided at the bottom of the condensate tray, the condensate drain pipe extends out of the box body, and a water outlet valve is provided on the condensate drain pipe.

[0056] The medium in the evaporator exchanges heat with the wet air. The heated medium in the evaporator enters the dehumidification heating pump equipment and then enters the condenser. The medium in the condenser exchanges heat with the gas passing through the second heat regenerator to heat the gas. The medium in the condenser enters the evaporator through the second pipeline after being cooled to achieve energy recovery.

[0057] The heat pump motor drives the blower to release dry hot air. The dry hot air contacts the sludge and takes away the moisture in the sludge to release humid air. Since the equipment is a closed space, the humid air moves downward and contacts the regenerator for heat exchange. The exchanged humid air contacts the evaporator, and the evaporator absorbs heat to form part of the condensed water, which is discharged to the sewage ditch. Another part of the cold air contacts the regenerator for heat exchange. The exchanged air contacts the condenser, and the condenser releases heat to form hot air, which is then transported to the blower. The heat pump motor then drives the blower to release dry hot air. In this way, a closed hot air cycle is performed to dry the moisture in the sludge.

[0058] The model of the evaporator is: ZL95BW-20H;

[0059] The model of the condenser is: WL20220411;

[0060] The model of the first heat exchanger and the second heat exchanger is plate type heat exchanger KXM15;

[0061] The model of the dehumidification heating pump equipment (compressor) is: SM147A4ALB;

[0062] The sludge treated in this application is strictly prohibited from containing flammable and explosive components; and it is strictly prohibited for sludge with too different properties to enter the dryer, especially highly viscous substances; the equipment of this application should be placed in a place that is windproof, rainproof, and lightning-proof; the condensate drain pipe and the wastewater station should have a drop of no less than 0.5 meters to facilitate drainage; the equipment should be maintained in strict accordance with maintenance specifications to prevent equipment damage, low work efficiency, and insufficient water removal efficiency. The power supply of the equipment should be stable, and unstable power may cause equipment failure or damage; the equipment of this application is used in an ambient temperature of 5-35 degrees and an ambient humidity of less than 85%. The moisture content of this application is lower than 55% or higher than 75%. Testing is required, and the sludge treated in the later operation should be consistent with the test sample. Only qualified personnel who have been trained can go to work.

[0063] Example 2

[0064] A. Feeding: The plate and frame sludge enters the wet hopper of the box-type machine, and the plate and frame filter press (existing equipment) unloads into the special sludge hopper; B. Forklift transportation to the equipment: Use a forklift to put the sludge hopper into the low-temperature drying box for drying, and use a forklift to transport the sludge hopper filled with wet sludge into the drying main machine; C. Box-type machine drying: After drying, the forklift transfers through the sludge hopper to unload. After the sludge hopper enters the dryer, it starts and runs automatically; D. Forklift transportation to the unloading rack: Use a forklift to lift the sludge hopper, open the bottom plate to unload into ton bags, and the dried sludge is transported to the unloading rack and unloaded into ton bags. The forklift transfers the ton bags to hazardous waste,

[0065] The condenser of the present application is an external wind condenser: the dryer wind condenser is installed on the top side of the dryer to ensure indoor ventilation.

[0066] The chemical machine condensate discharge pipe (DN32) of the present application has no pressure discharge and is designed with a flow rate of <0.1m3 / h.

[0067] The sludge from the filter press enters the wet hopper, and then the hopper filled with wet sludge is forked into the drying oven. The sludge is dried in the dryer and then packed and transported out. Adding a dehumidification and low-temperature drying system can greatly reduce the moisture content of the sludge, while reducing the bulk density of the sludge, reducing the cost of sludge treatment, and providing environmental protection and economic benefits for sludge disposal.

[0068] Single unit design scale: single mud input is about 1.5-1.8T;

[0069] Rated dehumidification capacity of a single unit: 1000KG / D water;

[0070] Moisture content after dehydration: recommended to be around 40% (can be adjusted between 35%-45%);

[0071] Drying mode: closed dehumidification and drying;

[0072] Drying heat source: heat pump condensation heat.

[0073] Comparative Example 1 adopts the low-temperature drying box of the prior art, and the rest of the structure is the same as that of the present application. The model of Comparative Example 1 is: JK-CSJ15WN-XT.

[0074] Table 1

[0075]

[0076]

[0077] Table 2

[0078]

[0079]

[0080] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A sludge drying and weight reduction method, characterized in that: The steps include: S1: The sludge is filtered and the sludge after filtering enters the sludge hopper; S2: The sludge hopper is transported to the low-temperature drying box for drying; S3: The sludge dried in step S2 is packed into bags for external transportation.

2. The sludge drying and weight reduction method according to claim 1, characterized in that: In the step S1, the sludge is filtered by a plate and frame filter press.

3. A low temperature drying box, applied to the sludge drying and weight reduction method according to any one of claims 1 to 2, characterized in that: The low-temperature drying box includes a box body and a middle partition, wherein the middle partition is arranged in the box body and the middle partition divides the box body into a drying area and a condensation heating area; There is a gap between the middle partition and the box, which allows the gas in the drying area of ​​the box to enter the condensation heating area; A drying assembly is provided in the drying area of ​​the box body, and a drying plate for placing a sludge hopper is provided in the drying assembly; A heat regenerator component and a condensing heat regenerating component are provided in the condensing heating area of ​​the box; A blower is provided in the condensation heating area of ​​the box body, and the gas treated in the condensation heating area is sent to the bottom of the drying plate of the drying assembly through the middle partition by the blower; One side of the box is open and is provided with a box door.

4. The low temperature drying box method according to claim 3, characterized in that: The drying assembly includes a base and a drying shell. The drying shell is arranged above the base. The top of the drying shell is open. A drying door is installed on one side of the drying shell close to the cabinet door. The drying door corresponds to the cabinet door. The drying plate is fixedly arranged in the drying shell.

5. The low temperature drying box method according to claim 3, characterized in that: The drying assembly includes a base and a drying shell. The drying shell is arranged above the base. The top of the drying shell is open. A drying door is installed on one side of the drying shell close to the cabinet door. The drying door corresponds to the cabinet door. The drying plate is fixedly arranged in the drying shell.

6. The low temperature drying box according to claim 3, characterized in that: The drying plate is provided with a first air vent that can allow air to circulate.

7. The low temperature drying box according to claim 3, characterized in that: A pipe hole is arranged on the middle partition plate, the blower is connected with the drying shell through a ventilation pipe, and the ventilation pipe is arranged below the drying plate.

8. The low temperature drying box according to claim 3, characterized in that: The regenerator assembly includes a first regenerator and a second regenerator; One side of the first heat regenerator and the second heat regenerator are connected via a heat exchange pipe; Further, the condensation heat recovery component includes an evaporator, a dehumidification heating pump device, and a condenser; The evaporator is arranged between the first regenerator and the second regenerator; The condenser is arranged below the second regenerator, and the upper part of the evaporator is connected to the lower part of the condenser through the first pipe; The upper part of the condenser is connected to the evaporator through a second pipe; The dehumidification heating pump device is arranged on the first pipeline.

9. The low temperature drying box according to claim 3, characterized in that: An expansion valve is arranged on the second pipeline.

10. The low temperature drying box according to claim 3, characterized in that: A condensate tray is provided at the bottom of the evaporator, which is arranged on the side wall of the box body. A condensate drain pipe is provided at the bottom of the condensate tray, which extends out of the box body and has a water outlet valve.

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