A plate-and-frame filter press for formaldehyde and methanol wastewater treatment

Abstract

The utility model discloses a kind of plate-and-frame filter press for formaldehyde, methanol wastewater treatment, it relates to filter press field.It includes rack, filter plate group, hydraulic pressure compaction device, filter cloth and liquid inlet pipeline assembly, liquid outlet pipeline assembly;Liquid inlet pipeline assembly is constituted by main liquid inlet pipe, ozone injection unit, heating stirring module, main liquid inlet pipe adopts coaxial nesting design, with liquid conveying inner layer and heat preservation outer layer, spiral stirring shaft is coaxially arranged in inner layer, nickel-chromium alloy heating wire is embedded in inner layer, heating temperature is regulated by pipe wall outer temperature control module;Liquid inlet pipe inlet end is connected ozone generator output pipeline by three-way flange, and venturi jet device is set downstream in three-way, liquid outlet pipeline assembly includes cyclone separator and activated carbon adsorption tank, cyclone separator cylinder is directly connected filter press liquid outlet by flange, top exhaust port is connected ozone reuse device.The filter press can effectively treat residual formaldehyde, methanol in wastewater during filter pressing process, and reduce the burden of wastewater post-treatment.

Description

Technical Field

[0001] This application relates to the field of filter presses, and in particular to a plate and frame filter press for treating formaldehyde and methanol wastewater. Background Technology

[0002] In the field of industrial wastewater treatment, plate and frame filter presses, as key equipment for solid-liquid separation, are widely used in the pretreatment stage of wastewater containing formaldehyde and methanol. In existing technologies, traditional plate and frame filter presses mainly use mechanical pressure to drive the filter cloth and filter plates to form a filtration chamber, separating the solid cake from the liquid filtrate. However, the core function of such equipment is limited to physical separation and fails to address the specific chemical characteristics of soluble organic pollutants such as formaldehyde and methanol. Due to their small molecular weight and high polarity, formaldehyde and methanol easily permeate with the filtrate or adsorb onto the surface of solid particles during filtration, resulting in a large amount of undecomposed organic pollutants remaining inside the filter cake after filtration. Especially when wastewater concentration fluctuates or the filtration cycle is long, residual pollutants are prone to secondary enrichment during filter cake accumulation, which not only increases the difficulty of subsequent harmless treatment but also may pose environmental risks due to the slow release of pollutants during filter cake storage or transportation.

[0003] The shortcomings of existing technologies mainly stem from the contradiction between the limited functionality of the equipment and the demands of pollutant treatment. On the one hand, the structural design of traditional filter presses is optimized to improve filtration efficiency and reduce moisture content. While parameters such as filter chamber sealing and pressure distribution uniformity can ensure solid-liquid separation, they cannot provide the temperature, catalyst contact, or oxidative decomposition conditions required for chemical reactions. On the other hand, filter cloth materials are mostly made of corrosion-resistant materials such as polypropylene. Although they possess good mechanical strength and filtration accuracy, their surfaces lack catalytically active sites or adsorption functional layers, making it difficult to achieve a synergistic effect of pollutant retention and degradation. Furthermore, the lack of a real-time control mechanism for filtrate reflux in the filter press process leads to the accumulation of some incompletely separated organic pollutants within the filter press system. These technological limitations make it difficult for traditional equipment to meet the increasingly stringent environmental standards for organic residue limits in the solid products after filter press treatment, while also increasing the overall cost of wastewater treatment for enterprises.

[0004] To address the aforementioned technical bottlenecks, developing a novel pressure filter that can simultaneously achieve efficient solid-liquid separation and formaldehyde and methanol degradation has significant application value. Utility Model Content

[0005] The purpose of this application is to overcome at least one deficiency of the prior art and provide a plate and frame filter press for the treatment of formaldehyde and methanol wastewater. This filter press can effectively treat residual methanol / formaldehyde in wastewater during the filtration process, thereby reducing the burden of wastewater post-treatment.

[0006] To achieve the above objectives, this application discloses a plate and frame filter press for treating formaldehyde and methanol wastewater. The plate and frame filter press includes a main structure comprising a frame, filter plate assembly, hydraulic pressing device, filter cloth and inlet pipe assembly, and outlet pipe assembly. The inlet and outlet pipe assembly, filter plate assembly and filter cloth structure are all functionally upgraded to meet the needs of formaldehyde and methanol wastewater treatment.

[0007] The specific improvement is as follows: the liquid inlet pipe assembly consists of a main liquid inlet pipe, an ozone injection unit, and a heating and stirring module. The main liquid inlet pipe adopts a coaxial nested design, with an inner layer for liquid transportation and an outer layer for heat preservation. A spiral stirring shaft is coaxially arranged in the inner layer. Preferably, the surface of the stirring shaft blades is provided with a flow guiding groove to enhance fluid turbulence. The inner layer is embedded with a nickel-chromium alloy heating wire, and the heating temperature is regulated by a temperature control module on the outside of the tube wall. The inlet end of the liquid inlet pipe is connected to the output pipe of the ozone generator through a tee flange, and a Venturi jet is installed downstream of the tee to use fluid kinetic energy to mix ozone with wastewater to form a uniform gas-liquid dispersion system.

[0008] Furthermore, while retaining the original pressure filtration function, the filter plate assembly has undergone coordinated optimization of the filter plate flow channel and filter cloth, including adding guide ribs to the inner wall of the liquid inlet channel of the filter plate in the filter plate assembly with multiple filter plates to extend the residence time of the mixed liquid.

[0009] Preferably, the filter cloth is made of polytetrafluoroethylene-coated glass fiber substrate, and its surface is loaded with a manganese dioxide catalyst layer to form a composite filter medium with catalytic oxidation function.

[0010] Furthermore, in the filter plate assembly, a high-temperature resistant rubber gasket layer is added to the sealing surface between adjacent filter plates to ensure the chamber sealing performance under high-temperature pressure filtration conditions.

[0011] Furthermore, the liquid outlet pipeline assembly integrates gas-liquid separation and adsorption purification functions, including a hydrocyclone separator and an activated carbon adsorption tank. The cylindrical body of the hydrocyclone separator is directly connected to the liquid outlet of the plate and frame filter press via a flange. Its conical section has built-in guide vanes to enhance the centrifugal separation effect, and the top exhaust port is connected to the ozone recovery device via a pipeline. The activated carbon adsorption tank has a built-in multi-layer gradient filling structure. The lower layer is granular activated carbon doped with iron and copper bimetals, and the upper layer is coconut shell activated carbon with a pore size of 2-5nm. The side wall of the activated carbon adsorption tank is equipped with a pressure sensor and a detachable observation window for monitoring the pressure difference of the adsorption layer and the filling status.

[0012] During the operation of this application, ozone-containing wastewater is pretreated by stirring and heating in the inlet pipe section and then enters the filter press chamber. Under the action of the catalytic filter cloth, the pollutants are degraded in a secondary manner, and finally purified by gas-liquid separation and activated carbon adsorption.

[0013] Compared with existing technologies, this design embeds the pollutant decomposition function into the main structure of the plate and frame filter press without adding any additional independent external equipment, thus achieving seamless coupling between the filter press process and the chemical reaction process.

[0014] The beneficial effects listed above are not exhaustive of all advantages. Other potential beneficial effects and detailed technical implementation methods will be further disclosed in the embodiments or other descriptive sections of this application. Attached Figure Description

[0015] A better understanding of various aspects of this disclosure will be achieved by reading the following detailed description in conjunction with the accompanying drawings. The positions, dimensions, and extents of the structures shown in the drawings, etc., do not always represent actual positions, dimensions, and extents. In the drawings: Figure 1 This is a schematic diagram of the structure of one embodiment disclosed in this application.

[0016] Figure 2 This is a schematic diagram of the internal structure of the main inlet pipe in one embodiment of the present application. Detailed Implementation

[0017] The present disclosure will now be described with reference to the accompanying drawings, which illustrate several embodiments of the present disclosure. However, it should be understood that the present disclosure can be presented in many different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the disclosure more complete and to fully illustrate the scope of protection of the present disclosure to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide further additional embodiments.

[0018] It should be understood that the same reference numerals denote the same elements in all the accompanying drawings. For clarity, the dimensions of certain features may be modified in the drawings.

[0019] It should be understood that the terminology used in this specification is for describing specific embodiments only and is not intended to limit this disclosure. All terms used in this specification (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. For the sake of brevity and / or clarity, techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail; however, where appropriate, such techniques, methods, and apparatus should be considered part of this specification.

[0020] Unless otherwise specified, the singular forms “a,” “the,” and “the” used in this specification include the plural forms. The terms “comprising,” “including,” and “containing” used in this specification indicate the presence of the claimed feature but do not exclude the presence of one or more other features. The term “and / or” used in this specification includes any and all combinations of one or more of the relevant listed items.

[0021] See attached document Figure 1 and 2 This embodiment discloses an exemplary structure of a plate and frame filter press for treating formaldehyde and methanol wastewater. Its overall structure is compact and fully functional, mainly consisting of a frame 1, filter plate assembly 2, hydraulic pressing device 3, filter cloth, inlet pipe assembly 4, and outlet pipe assembly 5. The components work closely together to achieve efficient treatment of formaldehyde and methanol wastewater. Specifically, the inlet pipe assembly 4, filter plate assembly 2, and filter cloth structure have all been specifically optimized to meet the particular needs of formaldehyde and methanol wastewater treatment.

[0022] The main inlet pipe 401 in the inlet pipe assembly 4 of this plate and frame filter press adopts a coaxial nested design. It has an inner layer and an outer layer. The inner layer is a corrosion-resistant alloy pipe with excellent corrosion resistance, capable of resisting the erosion of formaldehyde and methanol wastewater. Simultaneously, the insulation layer effectively reduces heat loss and ensures the stability of the liquid temperature inside the pipe. A spiral stirring shaft 402 is coaxially installed within the inner layer of the main inlet pipe 401. The blades of the stirring shaft are machined with guide grooves. When liquid flows through, these grooves guide the liquid flow in a specific direction, thereby enhancing the turbulence effect and ensuring thorough mixing of the liquid and gas, improving the efficiency of subsequent processing steps.

[0023] Furthermore, the inner layer of the main inlet pipe 401 has a nickel-chromium alloy heating wire 403, which is controlled by a temperature control module. This allows for precise regulation of the heating temperature, ensuring that the wastewater entering the filter press is within a suitable treatment range, thus creating favorable conditions for subsequent chemical reactions and other treatment steps.

[0024] The inlet end of the main liquid inlet pipe 401 is connected to the output pipe of the ozone generator through a tee flange. A Venturi jet is also installed downstream of the tee. When the wastewater flows through this point, the Venturi jet can fully mix the ozone with the wastewater by utilizing the kinetic energy of the fluid itself, forming a uniform gas-liquid dispersion system. This allows the ozone to be evenly dispersed in the wastewater, laying the foundation for the subsequent oxidation reaction.

[0025] Filter plate assembly 2 inherits the traditional pressure filtration function. The inner wall of the liquid inlet channel of filter plate 201 has guide ribs (not shown in the figure). These guide ribs can change the flow trajectory of the mixed liquid in the channel and prolong the residence time of the mixed liquid in the filter plate, thereby providing sufficient time for pollutants to fully contact and react with the catalyst on the filter cloth, and improving the treatment effect.

[0026] For filter cloths, for example, filter cloths with polytetrafluoroethylene (PTFE) membrane and glass fiber substrate can be used. The PTFE membrane gives the filter cloth good chemical resistance and surface smoothness, which is beneficial for liquid filtration and subsequent cleaning and maintenance, while the glass fiber substrate ensures the strength and filtration accuracy of the filter cloth.

[0027] In some embodiments, the filter cloth surface is loaded with a layer of manganese dioxide catalyst. This catalyst plays a crucial catalytic oxidation role in wastewater treatment, accelerating the decomposition and transformation of pollutants such as formaldehyde and methanol. This upgrades the filter cloth from a single filtration medium to a composite filtration medium with catalytic oxidation function, achieving simultaneous filtration and catalytic reactions. Furthermore, a high-temperature resistant rubber gasket layer is provided on the sealing surface between adjacent filter plates 201. Under high-temperature pressure filtration conditions, the rubber gasket layer can fit tightly, ensuring the airtightness of the pressure filtration chamber, preventing liquid leakage, and ensuring the smooth operation of the treatment process.

[0028] In this embodiment, the liquid outlet pipeline assembly 5 integrates gas-liquid separation and adsorption purification functions. The cylindrical body of the cyclone separator 501 is directly connected to the liquid outlet of the plate and frame filter press via a flange. Guide vanes are installed inside its conical section. When the liquid containing the gas-liquid mixture flows out of the filter press and into the cyclone separator, the guide vanes guide the liquid to form a high-speed rotating vortex. With the help of centrifugal force, efficient separation of gas and liquid is achieved, enhancing the centrifugal separation effect. The separated gas is discharged from the top exhaust port and connected to the ozone recovery device via pipeline 502, realizing the recycling of ozone and reducing treatment costs.

[0029] The liquid continues to flow to subsequent treatment stages. Activated carbon adsorption tank 503 is another core component of the effluent pipeline assembly 5. Its interior employs a multi-layered gradient filling structure. The lower layer is filled with granular activated carbon doped with iron and copper bimetallic materials. This specially doped activated carbon exhibits significantly enhanced adsorption performance, effectively adsorbing various harmful substances remaining in the wastewater. The upper layer is filled with coconut shell activated carbon with a pore size of 2-5 nm. Its fine pore structure allows for deep adsorption of small-molecule organic matter in the wastewater, further improving the effluent quality.

[0030] To facilitate monitoring of the adsorption process, a pressure sensor is installed on the side wall of the activated carbon adsorption tank 503 to monitor the pressure difference changes of the adsorption layer in real time. The magnitude of the pressure difference can be used to determine the adsorption saturation of the activated carbon, providing a basis for timely replacement of the activated carbon. At the same time, the tank is also equipped with a detachable observation window, which allows operators to intuitively observe the filling status of the adsorption layer and whether there are any abnormal phenomena such as flow deviation or channeling, ensuring the stability and reliability of the adsorption purification process.

[0031] It is important to understand that the above-mentioned components do not exist in isolation, but are closely integrated through pipeline topology optimization and modular assembly to form an organic whole.

[0032] In actual operation, ozone-containing wastewater first enters the inlet pipe assembly 4, where it undergoes pretreatment under the stirring action of the spiral stirring shaft and the heating action of the electric heating wire, bringing the wastewater to a suitable temperature and a uniformly mixed state. The wastewater then enters the filter press chamber, where, with the help of the filter cloth and the catalytic oxidation of manganese dioxide catalyst, the pollutants undergo secondary degradation treatment, further reducing the content of harmful substances such as formaldehyde and methanol in the wastewater. The treated liquid is discharged from the outlet and first enters the hydrocyclone separator 501 for gas-liquid separation. The separated gas is reused, while the liquid continues to flow to the activated carbon adsorption tank 503, where it undergoes deep adsorption purification by activated carbon, ultimately discharging compliant purified water. The entire treatment process integrates the pollutant decomposition function into the main structure of the plate and frame filter press, eliminating the need for additional independent external equipment. This achieves seamless coupling between the filter press process and the chemical reaction process, greatly improving the efficiency and effectiveness of wastewater treatment. It provides a new, efficient, and reliable solution for the treatment of formaldehyde and methanol wastewater, with broad application prospects.

[0033] While exemplary embodiments of this disclosure have been described, those skilled in the art will understand that various changes and modifications can be made to the exemplary embodiments of this disclosure without departing from the spirit and scope thereof. Therefore, all changes and modifications are included within the scope of protection of this disclosure as defined by the claims. This disclosure is defined by the appended claims, and equivalents of those claims are also included.

Claims

1. A plate and frame filter press for treating formaldehyde and methanol wastewater, characterized in that, The plate and frame filter press includes a main structure comprising a frame, filter plate assembly, hydraulic pressing device, filter cloth and inlet pipe assembly, and outlet pipe assembly. The inlet pipe assembly consists of a main inlet pipe, an ozone injection unit, and a heating and stirring module. The main inlet pipe adopts a coaxial nested design, having an inner layer for liquid transport and an outer layer for heat preservation. A spiral stirring shaft is coaxially arranged within the inner layer. A nickel-chromium alloy heating wire is embedded within the inner layer, and the heating temperature is controlled by a temperature control module outside the pipe wall. The inlet end of the inlet pipe is connected to the output pipe of the ozone generator via a three-way flange, and a Venturi jet injector is installed downstream of the three-way flange. The outlet pipe assembly includes a hydrocyclone separator and an activated carbon adsorption tank. The cylinder of the hydrocyclone separator is directly connected to the outlet of the plate and frame filter press via a flange, and the top exhaust port is connected to the ozone recycling device via a pipe.

2. The plate and frame filter press for treating formaldehyde and methanol wastewater as described in claim 1, characterized in that, The surface of the stirring shaft blades is provided with flow-guiding grooves to enhance fluid turbulence.

3. A plate and frame filter press for treating formaldehyde and methanol wastewater as described in claim 1, characterized in that... In filter plate assemblies containing multiple filter plates, guide ribs are added to the inner wall of the liquid inlet channel of the filter plates to extend the residence time of the mixture.

4. A plate and frame filter press for treating formaldehyde and methanol wastewater as described in claim 1, characterized in that, The filter cloth is made of polytetrafluoroethylene-coated glass fiber substrate, and its surface is loaded with a manganese dioxide catalyst layer to form a composite filter medium with catalytic oxidation function.

5. A plate and frame filter press for treating formaldehyde and methanol wastewater as described in claim 1, characterized in that, In the filter plate assembly, a high-temperature resistant rubber gasket layer is added to the sealing surface between adjacent filter plates.

6. A plate and frame filter press for treating formaldehyde and methanol wastewater as described in claim 1, characterized in that, The activated carbon adsorption tank has a built-in multi-layer gradient filling structure. The lower layer is granular activated carbon doped with iron and copper bimetals, and the upper layer is coconut shell activated carbon with a pore size of 2-5nm. The side wall of the activated carbon adsorption tank is equipped with a pressure sensor and a detachable observation window.

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