A positive deflection T-shaped two-stage filter

Abstract

The application discloses a positive baffle T-shaped two-stage filter and belongs to the technical field of fluid purification equipment. The device comprises a T-shaped cylinder body, a fluid inlet is arranged at one end of the head of the cylinder body, a flange cover is arranged at the other end of the head of the cylinder body, a fluid outlet is arranged at the lower part of the cylinder body, and a first-stage filter assembly is arranged axially at the head of the cylinder body. The internal passage of the fluid outlet is provided with a second-stage filter assembly, the second-stage filter assembly comprises a metal support framework and a second-stage filter screen arranged at the outer periphery of the metal support framework, and the second-stage filter screen is fixed to the outer wall surface of the metal support framework. The application adds an independent second-stage filter core with a metal framework at the fluid outlet, cooperates with the first-stage filter assembly to form coarse filtration and fine filtration, significantly improves the filtration precision, prolongs the overall service life of the filter screen, and the second-stage filter assembly is convenient to assemble and disassemble and low in maintenance cost.

Description

Technical Field

[0001] This invention relates to the field of fluid purification equipment technology, specifically to a positive baffle T-type two-stage filter. It is particularly suitable for high-precision fluid filtration scenarios in industrial pipeline systems such as petroleum, chemical, and power industries. Background Technology

[0002] Positive baffle T-type filters are common fluid purification devices in industrial piping systems. Their function is to trap solid particles entrained in the fluid, protecting downstream critical equipment such as pumps, valves, and compressors from wear and clogging. A typical structure of this type of filter is T-shaped, with a fluid inlet at one end of the cylindrical body, an openable flange cover at the other end, and a fluid outlet at the lower end. A cylindrical filter screen is axially installed at the head of the cylindrical body.

[0003] Existing positive baffle T-type filters have revealed numerous shortcomings in practical use. Traditional products only have a single-layer filter screen on the inlet side, and the filtration accuracy depends entirely on the mesh size of this layer. To improve filtration accuracy, only a finer filter screen can be selected, but this significantly increases fluid resistance, and the fine filter screen is easily clogged by particles, leading to frequent shutdowns for cleaning. At the same time, a single-stage filter screen bears the entire filtration load, and solid particles directly impact the filter screen surface, which can easily cause localized damage under high pressure and high flow rate conditions. Once damaged, the entire filter screen becomes ineffective and must be replaced, resulting in a short service life and high maintenance costs.

[0004] While improved two-stage filtration solutions have emerged in the market, each has its inherent drawbacks. One solution involves inserting a primary filter element into a horizontally positioned main pipe within a T-shaped duct body, and a secondary filter element into a vertically running branch pipe fixed to the center of the main pipe's perimeter. In this solution, the fluid, after being filtered by the primary filter, must be redirected into the branch pipe for secondary filtration, increasing local resistance loss due to the flow path bend; the branch pipe needs to be extended to accommodate the secondary filter element, significantly increasing the overall axial dimension of the unit; the secondary filter element is located deep within the branch pipe, making replacement difficult due to the limited operating space caused by the branch pipe's diameter and depth; furthermore, sealing structures are required at the connection between the branch pipe and the main pipe, as well as at the branch pipe end caps, increasing the risk of leakage.

[0005] Another option uses a concentric double-layer filter structure, where an inner circular filter screen is placed inside the outer circular frame, and the inner filter screen is completely surrounded by the outer filter screen. This design requires high processing precision, and the inner and outer layers need to be precisely matched, making assembly difficult; after the inner filter screen is wrapped by the outer layer, it is difficult to clean or replace it separately when clogged; the concentric arrangement of the inner and outer layers reduces the effective cross-sectional area for fluid flow, resulting in a significant increase in pressure drop; the inner filter screen lacks independent support and is prone to deformation after long-term use.

[0006] More importantly, there has long been a technical bias in this field, namely that the fluid outlet channel of a T-type filter is merely the final channel for the discharge of clean fluid, its function limited to flow guidance, and that no further filtration components are needed. Guided by this view, technicians generally lack the motivation to add a filtration structure within the outlet channel, believing that filtration is unnecessary there. Furthermore, the inner diameter of the fluid outlet channel is usually the same as the pipe diameter, resulting in very limited internal space. Embedding a complete filtration assembly with a support frame and filter screen within such a confined space, while ensuring that fluid resistance is not significantly increased, is not a simple matter of addition, but requires a delicate balance between structural compactness and filtration performance. To date, no technical solution for integrating a filtration assembly within the outlet channel of a T-type filter has been disclosed or used. Summary of the Invention

[0007] This invention addresses the technical problems of existing positive baffle T-type filters, such as insufficient filtration accuracy, short filter lifespan, and complex two-stage filtration structures, by providing a positive baffle T-type two-stage filter. This device improves overall filtration accuracy and dirt-holding capacity through the coordinated operation of the two filtration stages, extends the filter lifespan by providing structural support for the secondary filter screens through a metal frame, and achieves quick assembly, disassembly, and maintenance of the filter elements through a simplified assembly structure.

[0008] A positive baffle T-type two-stage filter includes a T-shaped cylindrical body. One end of the head of the T-shaped cylindrical body is provided with a fluid inlet, and the other end is provided with a removable flange cover. The lower port of the T-shaped cylindrical body is provided with a fluid outlet. A primary filter assembly is axially arranged at the head of the T-shaped cylindrical body. The primary filter assembly includes a support frame and a primary filter screen disposed on the outer periphery of the support frame. The primary filter screen covers the surface of the support frame and is used for initial filtration of the fluid flowing in from the fluid inlet.

[0009] Its innovation lies in the fact that a secondary filtration assembly is provided in the internal channel of the fluid outlet. The secondary filtration assembly includes a metal support frame and a secondary filter screen disposed on the outer periphery of the metal support frame. The metal support frame extends axially along the fluid outlet, forming a fluid channel within it. The secondary filter screen is fixed to the outer wall surface of the metal support frame. Fluid that has passed through the primary filter screen enters the fluid outlet and is filtered again by the secondary filter screen before being discharged.

[0010] Furthermore, the metal support frame is a cylindrical hollow structure made of stainless steel, and the area of ​​its hollow holes accounts for more than 60% of the frame's surface area to ensure that the pressure drop is controllable when fluid passes through.

[0011] Furthermore, a positioning square slot is provided at one end of the metal support frame near the inner wall of the fluid outlet, and the secondary filter assembly is pluggably installed inside the fluid outlet through the positioning square slot.

[0012] Furthermore, the secondary filter is fixed to the outer wall of the metal support frame by snap-fit.

[0013] Furthermore, the mesh size of the primary filter is smaller than that of the secondary filter, meaning that the primary filter assembly performs the coarse filtration function, while the secondary filter assembly performs the fine filtration function.

[0014] Furthermore, the inner wall of the fluid outlet is provided with a square slot, and both ends of the metal support frame are provided with matching square buckles to achieve detachable fixing of the secondary filter assembly.

[0015] Furthermore, the head of the T-shaped cylinder is also provided with a flushing port for connecting external cleaning media to perform reverse flushing of the primary and secondary filter components.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1) Structural simplification and space optimization

[0018] This invention places the secondary filtration assembly directly within the internal channel of the fluid outlet, eliminating the need for additional branch pipes or external filter chambers to accommodate the secondary filter element, as required by existing branch pipe connection schemes. This significantly reduces the overall axial dimension of the unit, by 20% to 30% compared to existing designs, allowing for greater flexibility in piping system layout. Simultaneously, the elimination of sealing structures at branch pipe connections and end caps reduces leakage risks and improves overall sealing reliability. This structural simplification facilitates assembly and disassembly, and also lowers manufacturing costs.

[0019] 2) Tiered interception improves filtration effect

[0020] The mesh sizes of the primary and secondary filters are not arbitrarily selected, but determined based on the principle of particle size classification and interception. The primary filter uses a lower mesh size, such as 40 mesh, to intercept large particulate impurities in the fluid; most particles with a diameter of 0.4 mm or larger are retained here. The secondary filter uses a higher mesh size, such as 80 mesh, to finely filter the small and medium-sized particles remaining after primary filtration; particles with a diameter of 0.18 mm or larger are removed. Because a large number of large particles have been removed in the primary filtration stage, the impact and dirt-holding burden on the secondary filter is significantly reduced, and the problem of easy clogging of fine filters is effectively alleviated. The load borne by the two filters is more balanced, and the service life of both is extended; it is not simply a matter of coarse filtration plus fine filtration superimposed.

[0021] 3) Improved filtration efficiency through optimized flow channels

[0022] After the fluid enters the head of the T-shaped cylinder through the inlet, it first undergoes axial filtration through a primary filter screen for coarse filtration. Then, it flows into the outlet channel at the lower port and undergoes radial filtration through a secondary filter screen for fine filtration before being discharged. This flow channel arrangement of axial coarse filtration, detour, and radial fine filtration utilizes the high inertia of large particles during the detour process, which helps them to be captured by the primary filter screen, producing a certain degree of inertial separation assistance. The combination of axial and radial filtration makes fuller use of the effective filtration area of ​​the filter screen. The primary coarse filtration has low resistance, while the secondary fine filtration has higher resistance but a smaller workload; the total pressure drop increase after the two are combined is less than the pressure drop increase when using a single fine-mesh filter screen alone.

[0023] 4) The supporting frame has multiple functions.

[0024] The secondary filter screen is fixed to the outer wall of a metal support frame. This frame has a cylindrical, hollow structure and serves three functions in actual use: first, it provides support, preventing the secondary filter screen from deforming or breaking under the impact of high-pressure fluid, thus extending the filter screen's service life; second, it guides the flow, with the hollow channels inside the frame ensuring smooth discharge of the filtered fluid; and third, it provides positioning, with square positioning slots at the ends of the frame facilitating quick insertion and removal and accurate positioning of the secondary filter assembly. This multi-functional integrated design makes the overall structure of the secondary filter assembly compact and functionally complete. Compared with the existing technology that uses independent filter cartridges or external supports, the number of parts is reduced, and assembly accuracy is easier to ensure. 5) Quantitative verification of comparative experimental data: To verify the technical effect of this invention, under the same experimental conditions (medium temperature water, flow rate 10m³ / h), 3 / h, sand content 200mg / L, initial pressure drop ΔP0=0.01MPa), the present invention was compared with existing typical solutions, and the results are as follows:

[0025]

[0026] Based on the experimental test results, the performance of this invention is as follows:

[0027] Regarding the initial pressure drop, this invention achieves 0.038 MPa, lower than the 0.040 MPa of the branch-pipe two-stage scheme. This advantage is primarily due to the reduction in local resistance losses resulting from the simplification of the flow path.

[0028] In terms of continuous filtration capability, the time for this invention to reach the pressure drop threshold is 240 hours, which is 5 times that of the single-stage solution and 1.67 times that of the branch pipe two-stage solution, indicating that this invention significantly extends the effective working time while maintaining filtration efficiency.

[0029] In terms of filtration accuracy, the present invention achieves an interception rate of 97.8% for particles with a diameter of 0.2 mm or greater, which is superior to the 82.4% of the single-stage solution and the 92.5% of the branch pipe two-stage solution.

[0030] In terms of ease of maintenance, the maintenance time required for a single operation of this invention is approximately 20 minutes, which is about four-sevenths to two-thirds of the time required by existing technologies, resulting in a significant improvement in maintenance efficiency.

[0031] Based on the above data, this invention outperforms existing solutions in terms of initial pressure drop, continuous working life, filtration accuracy, and maintenance efficiency. (See attached figures.)

[0032] Figure 1 This is a structural diagram of the present invention;

[0033] Figure 2 For the present invention Figure 1 Three-view diagram of the first-level filter component.

[0034] Figure 3 For the present invention Figure 1 Three-view diagram of the secondary filter component.

[0035] Figure 4 For the present invention Figure 1 3D diagram of the intermediate and secondary filter components;

[0036] Figure 5 For the present invention Figure 1 Enlarged view of point A in the image;

[0037] Figure 6 For the present invention Figure 1 Enlarged view of point B in the image.

[0038] The meanings of the labels in the attached figures are as follows: 1. Fluid inlet; 2. Fluid outlet; 3. Flange cover; 5. T-shaped cylinder; 6. Support frame; 7. Primary filter screen; 8. Metal support frame; 9. Secondary filter screen; 11. Positioning square slot; 10. Flushing interface. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example 1:

[0041] like Figure 1As shown, the present invention provides a positive baffle T-type two-stage filter comprising a T-shaped cylinder 5. A fluid inlet 1 is provided at one end of the head of the T-shaped cylinder 5, and a removable flange cover 3 is provided at the other end. A fluid outlet 2 is provided at the lower port of the T-shaped cylinder 5. A primary filter assembly is axially arranged at the head of the T-shaped cylinder 5, which consists of a support frame 6 and a primary filter screen 7 covering the surface of the support frame 6. After the fluid flows in through the fluid inlet 1, it first undergoes initial filtration through the primary filter screen 7.

[0042] A secondary filtration assembly is installed in the internal channel of fluid outlet 2. This secondary filtration assembly consists of a metal support frame 8 and a secondary filter screen 9 fixed to the outer wall of the metal support frame 8. The metal support frame 8 is a cylindrical perforated structure made of stainless steel, and the perforated area accounts for more than 60% of the frame's surface area. The metal support frame 8 extends axially along fluid outlet 2, forming a fluid channel inside. When the fluid that has passed through the primary filter screen 7 enters fluid outlet 2, it is filtered again by the secondary filter screen 9 before being discharged.

[0043] like Figure 2 As shown, a positioning square slot 11 is provided at one end of the metal support frame 8 near the inner wall of the fluid outlet 2. The secondary filter assembly is pluggably installed inside the fluid outlet 2 through this positioning square slot 11. The secondary filter screen 9 is fixed to the outer wall of the metal support frame 8 by clips. The mesh size of the primary filter screen 7 is smaller than that of the secondary filter screen 9, so that the primary filter assembly performs the coarse filtration function and the secondary filter assembly performs the fine filtration function.

[0044] like Figure 4 As shown, the inner wall of the fluid outlet 2 is provided with a square groove, and both ends of the metal support frame 8 are provided with matching square buckles. The secondary filter assembly is detachably fixed inside the fluid outlet 2 by the cooperation of the square buckles and the square groove. During maintenance, the secondary filter assembly can be individually cleaned or replaced simply by pulling it out from the fluid outlet 2 end, without having to disassemble the entire T-shaped cylinder 5.

[0045] like Figure 5 As shown, the head of the T-shaped cylinder 5 is also provided with a flushing port 10, which is used to connect external cleaning media to perform reverse flushing of the primary and secondary filter components, thereby further extending the service life of the filter components.

[0046] Example 2:

[0047] As another optional implementation, the mesh size of the primary filter 7 ranges from 20 to 40 mesh, and the mesh size of the secondary filter 9 ranges from 40 to 100 mesh. When the fluid medium is wastewater containing fibrous impurities, a 30-mesh primary filter 7 and a 60-mesh secondary filter 9 are used. This effectively intercepts fibrous impurities while preventing the rapid formation of a filter cake layer on the filter surface, further extending the cleaning cycle. When the fluid medium is under high pressure conditions containing high-hardness particles, a 60-mesh primary filter 7 and a 100-mesh secondary filter 9 are used. This achieves finer, graded interception, maximizing the protection of downstream precision equipment. Example 3:

[0048] As another optional implementation, the fixing method between the secondary filter 9 and the metal support frame 8 is not limited to snap-fit ​​connection; welding or stainless steel cable ties can also be used. For high-temperature and high-pressure conditions, with a medium temperature ≥200℃ and a pressure ≥4.0MPa, welding can prevent the snap-fit ​​from loosening due to thermal expansion, ensuring the long-term reliability of the secondary filter under extreme conditions. The working principle of this invention is as follows: Fluid enters the head of the T-shaped cylinder 5 from the fluid inlet 1, and large solid impurities in the fluid are intercepted by the primary filter 7, completing the initial filtration. Subsequently, the fluid flows towards the fluid outlet 2 at the lower port, where the remaining small and medium-sized particles are intercepted by the secondary filter 9 in the internal channel of the fluid outlet 2, completing the secondary filtration. The clean fluid after two stages of filtration is discharged from the fluid outlet 2 and enters downstream equipment. The secondary filter 9 maintains a stable structure under the support of the metal support frame 8, is not easily deformed or damaged, and effectively extends the service life of the filter. Throughout the filtration process, the primary coarse filter undertakes the task of intercepting large impurities, effectively reducing the filtration load of the secondary filter and forming a coordinated filtration effect of particle size classification and interception.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A positive baffle T-type two-stage filter, comprising a T-shaped cylinder (5), wherein a fluid inlet (1) is provided at one end of the head of the T-shaped cylinder (5) and a detachable flange cover (3) is provided at the other end, a fluid outlet (2) is provided at the lower port of the T-shaped cylinder (5), and a primary filter assembly is axially arranged at the head of the T-shaped cylinder (5), the primary filter assembly comprising a support frame (6) and a primary filter screen (7) disposed on the outer periphery of the support frame (6), characterized in that: A secondary filtration assembly is provided in the internal channel of the fluid outlet (2). The secondary filtration assembly includes a metal support frame (8) and a secondary filter screen (9) disposed on the outer periphery of the metal support frame (8). The secondary filter screen (9) is fixed to the outer wall surface of the metal support frame (8).

2. The positive baffle T-type dual-stage filter according to claim 1, characterized in that: The metal support frame (8) is a cylindrical hollow structure.

3. A positive baffle T-type dual-stage filter according to claim 2, characterized in that: The metal support frame (8) is made of stainless steel.

4. A positive baffle T-type dual-stage filter according to claim 1, characterized in that: The metal support frame (8) is provided with a positioning square slot (11) at one end near the inner wall of the fluid outlet (2), and the secondary filter assembly is pluggably installed inside the fluid outlet (2) through the positioning square slot (11).

5. A positive baffle T-type dual-stage filter according to claim 1, characterized in that: The secondary filter (9) is fixed to the outer wall of the metal support frame (8) by a snap fastener.

6. A positive baffle T-type dual-stage filter according to claim 1, characterized in that: The mesh count of the primary filter (7) is smaller than that of the secondary filter (9).

7. A positive baffle T-type dual-stage filter according to claim 1, characterized in that: The inner wall of the fluid outlet (2) is provided with a square slot, and the two ends of the metal support frame (8) are provided with matching square buckles.

8. A positive baffle T-type dual-stage filter according to claim 1, characterized in that: The head of the T-shaped cylinder (5) is also provided with a rinsing port (10).

9. The application of the positive baffle T-type two-stage filter according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1: The fluid to be filtered enters the head of the T-shaped cylinder (5) from the fluid inlet (1), flows axially through the primary filter assembly, and is intercepted by the primary filter screen (7) to complete the initial coarse filtration. S2: After the initial coarse filtration, the fluid turns at the head of the T-shaped cylinder (5) and flows into the fluid outlet (2) at the lower port. S3: The deflected fluid flows through the secondary filtration assembly in the internal channel of the fluid outlet (2), and the remaining small and medium-sized particles are intercepted by the secondary filter screen (9) fixed to the outer wall of the metal support frame (8), thus completing the secondary fine filtration; S4: The clean fluid after two-stage filtration is discharged from the fluid outlet (2).

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