A filter liquor decalcification and decontamination system bypassing fly ash

Abstract

The utility model discloses a kind of filtrate calcium-removing, heavy-duty treatment systems of bypass ash, including the solid-liquid separation of containing bypass ash mortar of ash ash, the filtrate of primary water-washing filter press enters reaction tank;Reaction tank carries out decalcification and heavy-duty treatment to filtrate;Reaction tank exports reactant to secondary water-washing filter press, and the filtrate after solid-liquid separation exports to neutralization tank, for neutralizing filtrate alkalinity;After liquid in neutralization tank meets PH value requirement, neutralization tank exports neutralization liquid to water supply ground tank, and the condensed water of evaporation is into water supply tank.The utility model realizes closed operation process in whole process, first neutralization in filtrate precipitate calcium and heavy metal, then solid-liquid separation, then PH value neutralization, finally produced water circulation production, realize no wastewater discharge, completely realize automation, harmlessness, resource, zero emission requirement.

Description

Technical Field

[0001] This utility model relates to the field of packaging cleaning technology, specifically to a system for decalcifying and degravimetric treatment of filtrate from bypass ventilation ash. Background Technology

[0002] Bypass ventilation systems have gradually become standard equipment in cement kilns for co-processing solid waste. The disposal of bypass ventilation ash containing elements such as calcium, heavy metals, alkali, chlorine, and sulfur released by the bypass ventilation system has also become increasingly prominent. Currently, the main method for treating and disposing of cement kiln bypass ventilation ash is to grind it with cement clinker to prepare cement. However, the treatment of calcium, heavy metals, and filtrate in the bypass ventilation ash is particularly important, as existing technologies cannot effectively handle these issues. Therefore, a technology is needed to remove calcium and heavy metals from the filtrate of bypass ventilation ash. Utility Model Content

[0003] Therefore, this utility model provides a system for decalcifying and deweighting the filtrate of bypass venting ash, in order to solve the problem that the prior art cannot effectively remove calcium and weight.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A system for decalcifying and deweighting the filtrate from bypass venting ash includes a primary water-washing filter press for solid-liquid separation of slurry containing bypass venting ash. The filtrate output from the primary water-washing filter press enters a reaction tank. The input end of the reaction tank is also connected to an alkali tank for outputting soda ash and a reagent tank for outputting heavy metal scavenging agent, which performs decalcification and deweighting treatment on the filtrate output from the filtrate tank. The fully reacted reactants from the reaction tank are fed to a secondary water-washing filter press for solid-liquid separation. The secondary water-washing filter press outputs the filtrate after solid-liquid separation to a neutralization tank. The neutralization tank is connected to an acid tank, which supplies acid to the neutralization tank to neutralize the alkalinity of the filtrate. Once the liquid in the neutralization tank meets the pH requirement, the neutralization tank outputs the neutralized liquid to a water supply tank for buffering. The water supply tank then supplies the neutralized liquid to be evaporated into the water supply tank.

[0006] Furthermore, the filtrate output from the primary water washing filter press is temporarily stored in the first filtrate tank, and the first filtrate tank outputs the filtrate to the reaction tank.

[0007] The filtrate output from the secondary water washing filter press enters the second filtrate tank for temporary storage, and the second filtrate tank outputs the filtrate to the neutralization tank.

[0008] Furthermore, the slurry containing bypass vent ash is conveyed to the metering tank via a feeding device. The metering tank measures the bypass vent ash and then sends it to the mixing tank. The input end of the mixing tank is also connected to a water measuring tank. The mixing tank conveys the premixed material to the pulping tank. The pulping tank conveys the slurry containing bypass vent ash to the primary water washing filter press.

[0009] Furthermore, the filtrate output from the primary water washing filter press enters the measuring water tank.

[0010] Furthermore, the output end of the water supply tank is connected to a primary water washing filter press to provide washing water to the primary water washing filter press.

[0011] Furthermore, a pH sensor is installed inside the neutralization tank.

[0012] The present invention has the following advantages:

[0013] This utility model discloses a closed-loop operation process for the calcium and heavy metal removal treatment of filtrate from bypass venting ash. Calcium and heavy metals are precipitated through neutralization of the filtrate, followed by solid-liquid separation and pH neutralization of the filtrate to obtain water that meets discharge requirements. This effectively removes calcium and heavy metals from the filtrate of bypass venting ash. Moreover, the system has a clear route, no wastewater discharge, and fully achieves automation, harmlessness, resource utilization, and zero discharge requirements. Attached Figure Description

[0014] To more clearly illustrate the embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0015] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0016] Figure 1 A system structure diagram of a bypass venting ash filtrate calcium and gravity removal treatment system provided for an embodiment of this utility model;

[0017] In the picture:

[0018] 1. Feeding device; 2. Metering tank; 3. Water measuring tank; 4. Mixing tank; 5. Pulping tank; 6. Primary water washing filter press; 7. First filtrate tank; 8. Reaction tank; 9. Alkali tank; 10. Reagent tank; 11. Secondary water washing filter press; 12. Second filtrate tank; 13. Neutralization tank; 14. Water supply tank; 15. Water supply tank. Detailed Implementation

[0019] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0020] like Figure 1 As shown, a system for decalcifying and degravimetric treatment of filtrate from bypass venting ash includes a primary water-washing filter press 6 for solid-liquid separation of slurry containing bypass venting ash. The slurry containing bypass venting ash is fed to a metering tank 2 via a feeding device 1. The metering tank 2 meters the bypass venting ash and then sends it to a mixing tank 4. The input end of the mixing tank 4 is also connected to a water measuring tank 3. The mixing tank 4 conveys the premixed material to a pulping tank 5. The pulping tank 5 conveys the slurry containing bypass venting ash to the primary water-washing filter press 6.

[0021] Specifically, the feeding device 1 is used to contain bypass venting ash and transport the bypass venting ash to a high place, where it enters the metering tank 2 from the top.

[0022] The metering tank 2 is used to measure the volume of bypass vent ash, and the water measuring tank 3 is used to measure the volume of the mixed liquid. Metering tanks 2 and 3 respectively measure the corresponding volumes of substances and send them to the mixing tank 4. The dry powdered bypass vent ash is pre-mixed with part or all of the mixed liquid to obtain a uniformly mixed slurry. This step ensures thorough mixing of the bypass vent ash and water, preventing the bypass vent ash from floating on the water surface and failing to dissolve. In this step, the mixing tank 4 uses a high-speed mixer with high stirring speed and large shear force. The mixing time in the mixing tank 4 is relatively short, only requiring the removal of most dry powder and large lumps. This treatment prevents premature over-hydration due to excessive stirring, which can trap air and form difficult-to-eliminate bubbles.

[0023] The pulping tank 5 applies high-intensity shear force to the premixed material for stirring and pulping, resulting in a smooth, uniform, fine, and non-granular liquid homogenized slurry with appropriate viscosity and thixotropy, which is the mortar. The discharge end of the pulping tank 5 is connected to the inlet end of a water-washed filter press, sending the mortar into the primary plate and frame filter press. The pulping tank 5 uses a high-speed, high-shear mixer, such as a high-speed dispersing disc mixer, a high-speed paddle mixer, or a stator-rotor homogenizer, which can provide strong shear force and turbulence. The pulping time is relatively long and more critical, usually 2 to 5 minutes or longer. Insufficient time will lead to uneven dispersion and poor performance; excessive time may introduce too many air bubbles or damage the established structure.

[0024] The primary plate and frame filter press performs solid-liquid separation on the slurry. The separated solid filter cake is sent to other processing systems via a conveying device, while the separated primary filtrate is sent to the reaction tank 8 for decalcification and degravation treatment to obtain the reactants. To ensure the stability and continuity of system operation, a first filtrate tank 7 is provided between the primary plate and frame filter press and the reaction tank 8 for temporary storage of the filtrate. This eliminates the need to adjust the working efficiency of the primary plate and frame filter press and the reaction tank 8, as the first filtrate tank 7 can match their working efficiency. Moreover, if the primary plate and frame filter press or the reaction tank 8 malfunctions, the first filtrate tank 7 can act as an isolation device, preventing liquid discharge.

[0025] The reaction vessel 8 is connected to the alkali tank 9 and the reagent tank 10. The alkali tank 9 metered and transported the soda ash to the reaction vessel 8 for decalcification by reacting with calcium and magnesium. The reagent tank 10 contains heavy metal scavenging agents, flocculants, and other reagents, which are pumped into the reaction vessel 8 for weight removal, flocculation, and sedimentation. After thorough mixing in the reaction vessel 8, the reactants are obtained. The stirring speed in the reaction vessel 8 is 50-80 rpm. The reaction endpoint is determined through empirical analysis, typically by titration analysis to determine the color change of the reaction solution to indicate whether the reaction is complete.

[0026] The reaction tank 8 outputs the fully reacted reactants to the secondary water washing filter press 11 for solid-liquid separation. The secondary water washing filter press 11 then conveys the separated filter cake to other systems via a conveying device. The filtrate from the solid-liquid separation is output to the neutralization tank 13 to adjust the pH value of the filtrate. To ensure the stability and continuity of system operation, the filtrate output from the secondary water washing filter press 11 is temporarily stored in the second filtrate tank 12. The second filtrate tank 12 then outputs the filtrate to the neutralization tank 13. This eliminates the need to adjust the working efficiency of the secondary plate and frame filter press and the neutralization tank 13, as the second filtrate tank 12 can match their working efficiency. Furthermore, if the secondary plate and frame filter press or the neutralization tank 13 malfunctions, the second filtrate tank 12 can act as an isolation device, preventing liquid discharge issues.

[0027] The neutralization tank 13 is connected to the acid tank, which supplies acid solution to the neutralization tank 13. In this embodiment, the acid solution is hydrochloric acid with a concentration of ≥25%, used to neutralize the alkalinity of the filtrate. The neutralization tank 13 is equipped with a stirring structure to accelerate the neutralization process between the second filtrate and the hydrochloric acid, ultimately obtaining a neutralized solution that meets the pH requirements. The neutralization tank 13 is also equipped with a pH sensor for online pH monitoring; any unqualified solutions are returned to the second filtrate tank 12.

[0028] Once the liquid in neutralization tank 13 meets the pH requirement, it outputs the neutralized liquid to the water supply tank 14 for buffering. The water supply tank 14 then transfers the neutralized liquid to the water supply tank 15 for evaporation. The water supply tank 15 is equipped with an online density meter, and the final chloride concentration (a mixed salt solution of potassium chloride and sodium chloride) in the water supply tank 15 is approximately 8.6%, free of acid and alkali, meeting safety emission standards. The water in the water supply tank 15 is sent to the measuring tank 3 for mixing the bypass vent ash; alternatively, the water in the supply pipe is sent to the primary water washing filter press 6 to wash the solid filter cake from solid-liquid separation. The washing liquid is then sent back to the measuring tank 3. This design, which uses filtered water for recycling, significantly saves water resources and prevents leakage, achieving a fully enclosed system that is safe and environmentally friendly.

[0029] Although the present invention has been described in detail above with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A system for treating calcium and heavy metal removal from the filtrate of bypass venting ash, characterized in that: Includes a primary water-washing filter press for solid-liquid separation of mortar containing bypass venting ash, wherein the filtrate output from the primary water-washing filter press enters a reaction tank; The input end of the reaction vessel is also connected to an alkali tank for outputting soda ash and a reagent tank for outputting heavy metal scavenging agent, and the filtrate output from the filtrate tank is subjected to decalcification and deweighting treatment. The reaction tank outputs the fully reacted reactants to a secondary water washing filter press for solid-liquid separation. The secondary water washing filter press outputs the filtrate after solid-liquid separation to a neutralization tank. The neutralization tank is connected to an acid tank, which supplies acid to the neutralization tank to neutralize the alkalinity of the filtrate. Once the liquid in the neutralization tank meets the pH requirement, the neutralization tank outputs the neutralized liquid to the water supply tank for buffering. The water supply tank then transports the neutralized liquid to be evaporated into the water supply tank.

2. The system for decalcification and degravity removal of filtrate from bypass venting ash according to claim 1, characterized in that: The filtrate output from the primary water washing filter press enters the first filtrate tank for temporary storage, and the first filtrate tank outputs the filtrate to the reaction tank. The filtrate output from the secondary water washing filter press enters the second filtrate tank for temporary storage, and the second filtrate tank outputs the filtrate to the neutralization tank.

3. The system for decalcification and degravimetric treatment of filtrate from bypass venting ash according to claim 1, characterized in that: The slurry containing bypass vent ash is fed to a metering tank via a feeding device. The metering tank measures the bypass vent ash and then sends it to a mixing tank. The input end of the mixing tank is also connected to a water measuring tank. The mixing tank delivers the premixed material to a pulping tank. The pulping tank delivers the slurry containing bypass vent ash to a primary water washing filter press.

4. The system for decalcification and degravimetric treatment of filtrate from bypass venting ash according to claim 3, characterized in that: The filtrate output from the primary water washing filter press enters the measuring water tank.

5. The system for decalcification and degravity removal of filtrate from bypass venting ash according to claim 1, characterized in that: The output end of the water supply tank is connected to the primary water washing filter press, providing washing water to the primary water washing filter press.

6. The system for decalcification and degravimetric treatment of filtrate from bypass venting ash according to claim 1, characterized in that: The neutralization tank is equipped with a pH sensor.

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