CN212327627U - Prefilter with dual filtering functions - Google Patents

Abstract

The utility model relates to a leading filter with dual filtering capability. It has solved the not good and filter material low-usage problem of water filter effect among the prior art, it is including having inner chamber filter casing, filter casing one side has the water inlet, and it has delivery port and lower extreme closure to filter the casing upper end, it is equipped with the filter container in the filter casing, filter container upper end and the inboard circumference of filter casing upper end are sealed, lower extreme and the inboard circumference of filter casing lower extreme are sealed, it is equipped with the filter support body to overlap in the outside of filter container circumference, filter support body circumference has the filter screen, form the primary filter chamber that is linked together with the raw water cavity between the inboard and the filter container circumference outside of filter screen circumference, secondary filter chamber has in the filter container, secondary filter chamber upper end is linked together with the delivery port, secondary filter chamber lower extreme is linked together. The utility model has the advantages that: the filter effect is good and the utilization rate of the filter material is improved.

Description

Prefilter with dual filtering functions

Technical Field

The utility model relates to a water quality filtering equipment field, concretely relates to leading filter with dual filtering capability.

Background

Through the propaganda and the popularization of many years drinking water health knowledge, people know the influence of drinking water quality to health gradually, attach more importance to drinking water safety, wherein leading water purifier is the first coarse filtration equipment to the whole room water, generally install the front end at the pipeline, the main objective is that the produced sediment impurity of getting rid of pipeline and bacterium, the microorganism remains, the iron rust, granule impurity more than 5 microns such as sand mud are greater than, in order to ensure that a large amount of sediment impurity that produces can not cause the injury to the human body in the pipe network, and play positive guard action to applying the pipeline secretly, tap, electrical apparatus etc.. The existing preposed water purifier can only filter particle impurities, can not remove impurities such as ammonia, nitrogen and heavy metals in a water body, has poor water purification effect, has the defects of insecure installation of a filter element, inconvenient replacement and the like, and simultaneously, when the existing preposed water purifier is used, part of water entering the filter does not completely flow out of a water outlet through the filtering material, so that the water purifying material is not fully utilized, the water quality purification effect is influenced, and the filtering efficiency is reduced.

In order to solve the defects of the prior art, people have long searched for and put forward various solutions. For example, the chinese patent literature discloses a multifunctional front water purifier [ CN201821220186.1], which includes a definite type that discloses a multifunctional front water purifier, including a filter element assembly, a connector and a cup cover; the filter element assembly comprises a PP cotton filter element pipe, zeolite, a plug and a tail cover, wherein the zeolite is filled in the PP cotton filter element pipe, the plug and the tail cover are respectively connected to two ends of the PP cotton filter element pipe and used for plugging the zeolite in the PP cotton filter element pipe, and a water outlet hole communicated with the interior of the PP cotton filter element pipe is formed in the plug; the left end and the right end of the connector are respectively provided with a water inlet connector and a water outlet connector, the lower part of the connector is provided with a water inlet and a slot, the water inlet connector is communicated with the water inlet, the water outlet connector is communicated with the slot, and the plug is inserted into the slot; the cup cover is arranged outside the filter element assembly, the water inlet is communicated with the cavity between the cup cover and the filter element assembly, the cup opening of the cup cover is in threaded connection with the lower portion of the connector, the elastic compression piece is arranged at the bottom of the cup cover, and the elastic compression piece is supported between the tail cover and the cup cover.

Above-mentioned scheme has solved to a certain extent among the prior art not good and the filter core installation insecure of water filter effect, changes inconvenient problem, but this scheme still has a great deal of not enough, for example: part of water entering the filter flows out without passing through the filtering material completely, so that the utilization rate of the filtering material is reduced, and the filtering effect of water quality is influenced.

Disclosure of Invention

The utility model aims at the above-mentioned problem, provide a reasonable in design, the leading filter that has dual filtering capability that filter material high-usage and filter effect are good.

In order to achieve the above purpose, the utility model adopts the following technical proposal: the pre-filter with double filtering functions comprises a filtering shell with an inner cavity, a water inlet is arranged at one side of the filtering shell, the upper end of the filtering shell is provided with a water outlet, the lower end of the filtering shell is closed, the filtering shell is provided with a hollow filtering container which is positioned in the inner cavity, the upper end of the filtering container and the inner side of the upper end of the filtering shell are sealed circumferentially, the lower end of the filtering container and the inner side of the lower end of the filtering shell are sealed circumferentially, and a filter frame body is sleeved on the outer side of the circumferential direction of the filter container, and a filter screen is arranged on the circumferential direction of the filter frame body, a raw water cavity communicated with the water inlet is formed between the circumferential inner side of the filtering shell and the circumferential outer side of the filter screen, and a primary filter cavity communicated with the raw water cavity is formed between the circumferential inner side of the filter screen and the circumferential outer side of the filter container, and a secondary filter cavity for placing filter materials is arranged in the filter container, the upper end of the secondary filter cavity is communicated with the water outlet, and the lower end of the secondary filter cavity is communicated with the primary filter cavity through an annular flow guide structure. Through set up the filter screen in the filter frame body week outside, the water that will get into in the filter housing carries out the first time and filters, and simultaneously, set up annular water conservancy diversion structure bottom the filter frame body, will be through first time filterable water direction filter vessel bottom, get into the second grade filter chamber from filter vessel bottom and filter, because the water that filters in the casing to the entering has carried out twice and has filtered, the filter effect is good, and because first time filterable water gets into the second grade filter chamber from filter vessel bottom, the filtration that filtering material is complete has passed through, the utilization ratio of filtering material has been improved.

In foretell leading filter with dual filtering capability, filter the casing and be split type structure and form by last casing and casing detachable connections down, water inlet and delivery port all set up on last casing, and the casing lower extreme seals down, and filters the inboard circumference seal in container upper end and last casing upper end, and lower extreme and the inboard circumference seal of casing lower extreme down. Therefore, the water entering the raw water cavity can be prevented from directly flowing out, and the sealing effect is good.

In foretell leading filter with dual filtering capability, it is uncovered that filtering container is the tube-shape and filters the container upper end, and the lower extreme is equipped with the lower shrouding that has a plurality of lower through-holes, and filters the support body and be the tubular structure that circumference has a plurality of thru holes, filters the coaxial cover of support body and establish in the filtering container circumference outside, filters the support body upper end and is equipped with and can open the last shrouding that seals and have a plurality of through-holes in filtering container upper end, and filters the support body lower extreme and pass through joint location structure and filter the container lower extreme and link to. The setting of joint location structure can avoid filtering the support body and rock because of the too big production of rivers, and stability is good.

In the above-mentioned prefilter with dual filtering functions, the lower end of the filter frame body extends to the lower end of the filter container, the filter net is sleeved outside the circumferential direction of the filter frame body, the filter net covers the outer side surface or partial outer side surface of the whole filter frame body, and the annular flow guide structure is arranged between the lower end of the filter container and the lower end of the filter frame body. The setting of annular water conservancy diversion structure can make the rivers reposition of redundant personnel through the filter screen get into the filter container bottom, avoids the water velocity too fast to lead to filtering material to filter the not thorough condition inadequately.

In the above pre-filter with dual-filtration function, the lower end of the filtration container is provided with a connecting cylinder body coaxially connected with the filtration container, the diameter of the connecting cylinder body is smaller than that of the filtration container, an annular step is formed between the circumferential outer side of the upper end of the connecting cylinder body and the circumferential outer side of the filtration container, and the lower sealing plate is arranged at the lower end of the connecting cylinder body.

In foretell leading filter with dual filtering capability, annular water conservancy diversion structure includes that a plurality of settings are in the connecting cylinder circumference outside and along the connecting cylinder axially extended connecting strip, and the connecting strip outside does not surpass the filtering container outside, and connecting strip one end extends to annular step department, the other end extends to the lower shrouding circumference outside of connecting cylinder lower extreme, connecting cylinder lower extreme circumference outside is equipped with the coaxial setting of connecting cylinder and the water conservancy diversion seat that links to each other with each connecting strip lower extreme circumference outside, and water conservancy diversion seat lower extreme and lower shrouding lower extreme constitute the water conservancy diversion chamber jointly with filter housing bottom, and the water conservancy diversion chamber is linked together through lower through-hole and secondary filter chamber, and the water conservancy diversion chamber is linked together through annular water conservancy diversion subassembly and primary filter chamber. The setting of water conservancy diversion chamber can make and pile up the effect to rivers formation, alleviates filtering pressure of interior filter material of filter container.

In the above-mentioned prefilter with dual filtering functions, the annular diversion component includes a diversion channel which is arranged between the circumferential inner side of the diversion seat and the circumferential outer side of the lower end of the connecting cylinder and is positioned between any two adjacent connecting strips, and one end of the diversion channel is communicated with the primary filtering cavity, and the other end is communicated with the diversion cavity.

In foretell leading filter with dual filtering capability, joint location structure is including setting up the annular position circle in the water conservancy diversion seat upper end circumference outside, and the annular position circle circumference outside is located to the lower pot head of filter support body, and filters the support body lower extreme and lean on the location step that sets up between annular position circle and water conservancy diversion seat, and annular position circle upper end has the location strip that a plurality of circumference distribute the setting, and location strip upper end has the buckle body that links to each other with the constant head tank joint of filter support body lower extreme. Fix the filter support body lower extreme through the buckle body, form detachable construction, be convenient for filter support body overhaul, wash.

In foretell leading filter with dual filtering capability, it has last annular seal inclined plane to filter between support body upper end circumference outside and the last shrouding circumference outside, and go up annular seal inclined plane and filter casing upper end circumference inboard seal, and filter support body upper end circumference outside has the last seal ring groove that is located the sealed inclined plane below of last annular, water conservancy diversion seat lower extreme flushes with shrouding lower extreme down, water conservancy diversion seat lower extreme circumference outside has lower annular seal inclined plane, and lower annular seal inclined plane and filter casing lower extreme circumference inboard seal, and water conservancy diversion seat circumference outside has lower seal ring groove. The arrangement effectively prevents the condition that water entering the raw water cavity is directly discharged from the water outlet without being filtered.

In foretell leading filter with dual filtering capability, go up the casing and link to each other through the screw thread with lower casing, and filter the casing and be thick and the thin fusiform structure in both ends in the middle of being, and go up casing circumference and have a plurality of upper sunken faces that set up along vertical direction, and casing circumference has a plurality of lower sunken faces that are the setting of heliciform distribution down. Go up the casing and link to each other through the screw thread with lower casing, it is convenient to dismantle, and goes up sunken face and lower sunken face's setting beautifully beautiful.

Compared with the prior art, the utility model has the advantages of: simple structure, it is convenient to dismantle, carries out a lot of through filter screen and filter vessel to the water that gets into former water cavity and filters, and the filter effect is good, simultaneously, because the setting of annular water conservancy diversion structure, makes the water through the primary filter chamber get into the secondary filter chamber from the filter vessel bottom, makes the filtering material utilization of secondary filter intracavity obtain the maximize, has improved filtering material's utilization ratio.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention;

fig. 2 is a sectional view of the utility model;

fig. 3 is a schematic structural view of the filter container, the clamping positioning structure and the annular flow guide structure of the utility model when they are connected with each other.

FIG. 4 is a schematic view of the structure of the filtering frame body of the utility model;

fig. 5 is a schematic structural view of the bottom of the guide seat and the filtering container of the utility model.

In the figure, the filter housing 1, the water inlet 11, the water outlet 12, the upper housing 13, the lower housing 14, the upper concave surface 131, the lower concave surface 141, the filter container 2, the secondary filter chamber 21, the lower sealing plate 22, the lower through hole 221, the connecting cylinder 23, the annular step 24, the filter frame body 3, the filter screen 31, the through hole 32, the upper sealing plate 33, the through hole 331, the positioning groove 34, the upper annular sealing inclined surface 35, the upper sealing ring groove 36, the raw water chamber 4, the primary filter chamber 5, the annular flow guide structure 6, the connecting strip 61, the flow guide seat 62, the flow guide chamber 63, the lower annular sealing inclined surface 64, the lower sealing ring groove 65, the clamping positioning structure 7, the annular positioning ring 71, the positioning step 72, the positioning strip 73, the clamping body 74, the annular flow guide assembly 8, and the flow.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

As shown in fig. 1-5, the prefilter with dual filtering functions comprises a filtering shell 1 having an inner cavity, a water inlet 11 is arranged on one side of the filtering shell 1, a water outlet 12 is arranged on the upper end of the filtering shell 1, the lower end of the filtering shell is sealed, the filtering shell 1 is provided with a hollow filtering container 2 which is arranged in the inner cavity, the upper end of the filtering container 2 and the upper end of the filtering shell 1 are circumferentially sealed, the lower end of the filtering shell 1 and the lower end of the filtering shell are circumferentially sealed, a filtering frame body 3 is sleeved on the circumferential outer side of the filtering container 2, a filtering net 31 is circumferentially arranged on the filtering frame body 3, a raw water cavity 4 communicated with the water inlet 11 is formed between the circumferential inner side of the filtering shell 1 and the circumferential outer side of the filtering net 31, a primary filtering cavity 5 communicated with the raw water cavity 4 is formed between the circumferential inner side of the filtering net 31 and the, the upper end of the secondary filter cavity 21 is communicated with the water outlet 12, and the lower end of the secondary filter cavity 21 is communicated with the primary filter cavity 5 through the annular flow guide structure 6. Water entering the raw water cavity 4 is filtered for a plurality of times through the filter screen 31 and the filter container 2, the filtering effect is good, water passing through the primary filter cavity 5 enters the secondary filter cavity 21 from the bottom of the filter container 2 through the annular flow guide structure 6, and filtering materials in the secondary filter cavity 21 are fully utilized.

Wherein, filter casing 1 and be split type structure and form by last casing 13 and 14 removable concatenations of casing down, water inlet 11 and delivery port 12 all set up on last casing 13, and casing 14 lower extreme seals down, and filters 2 upper ends of container and the inboard circumference seal in 13 upper ends of last casing, and lower extreme and the inboard circumference seal in 14 lower extremes of casing down. The upper shell 13 and the lower shell 14 are detachably connected through a thread structure, so that the water outlet is convenient to disassemble and assemble, a water flow guide part is in threaded connection with the inner side of the circumferential direction of the water outlet 12, and the upper end of the water flow guide part is connected with the lower end of the water outlet 12 in a clamping mode.

Visibly, the filtering container 2 is cylindrical and the upper end of the filtering container 2 is open, the lower end of the filtering container is provided with a lower sealing plate 22 with a plurality of lower through holes 221, the filtering frame body 3 is a cylindrical structure with a plurality of through holes 32 in the circumferential direction, the filtering frame body 3 is coaxially sleeved on the outer side of the filtering container 2 in the circumferential direction, the upper end of the filtering frame body 3 is provided with an upper sealing plate 33 which can seal the upper end of the filtering container 2 open and is provided with a plurality of upper through holes 331, and the lower end of the filtering frame body 3 is connected with the lower end of the filtering container. The upper through hole 331 is used for discharging filtered water through the water flow guide member, the bottom of the water flow guide member is abutted against the upper through hole 331, and the middle part of the water flow guide member is provided with a flow guide channel communicated with the water outlet 12.

Further, 3 lower extremes of filter frame body extend to the 2 lower extremes of filter vessel, and 3 circumference outsides of filter frame body are overlapped to filter 31 cover and 3 lateral surfaces of whole filter frame body or partial lateral surfaces are covered to filter 31 cover, and annular water conservancy diversion structure 6 sets up between 2 lower extremes of filter vessel and the 3 lower extremes of filter frame body.

Obviously, the lower end of the filtering container 2 is provided with a connection cylinder 23 coaxially connected with the filtering container 2, and the diameter of the connection cylinder 23 is smaller than that of the filtering container 2, an annular step 24 is formed between the circumferential outer side of the upper end of the connection cylinder 23 and the circumferential outer side of the filtering container 2, and a lower closing plate 22 is provided at the lower end of the connection cylinder 23.

In detail, annular water conservancy diversion structure 6 includes a plurality of settings in the connecting cylinder 23 circumference outside and along connecting cylinder 23 axial extension's connecting strip 61, and the connecting strip 61 outside does not surpass the 2 outsides of filter container, and connecting strip 61 one end extends to annular step 24 department, the other end extends to the lower shrouding 22 circumference outside of connecting cylinder 23 lower extreme, connecting cylinder 23 lower extreme circumference outside is equipped with the coaxial setting of connecting cylinder 23 and the water conservancy diversion seat 62 that links to each other with each connecting strip 61 lower extreme circumference outside, and water conservancy diversion seat 62 lower extreme and lower shrouding 22 lower extreme constitute water conservancy diversion chamber 63 with filtering shell 1 bottom jointly, and water conservancy diversion chamber 63 is linked together through lower through-hole 221 and second grade filter chamber 21, and water conservancy diversion chamber 63 is linked together through annular water conservancy diversion subassembly 8 and first grade filter.

Furthermore, the annular flow guiding assembly 8 includes a flow guiding channel 81 disposed between the circumferential inner side of the flow guiding seat 62 and the circumferential outer side of the lower end of the connecting cylinder 23 and located between any two adjacent connecting strips 61, and one end of the flow guiding channel 81 is communicated with the primary filtering cavity 5, and the other end is communicated with the flow guiding cavity 63. The diversion channel 81 is used for relieving the water flow speed.

Specifically, joint location structure 7 is including setting up annular position circle 71 in the water conservancy diversion seat 62 upper end circumference outside, and the annular position circle 71 circumference outside is located to the end cover under the filter support body 3, and filter support body 3 lower extreme support to lean on setting up on the location step 72 between annular position circle 71 and water conservancy diversion seat 62, and annular position circle 71 upper end has the location strip 73 that a plurality of circumference distribute the setting, and location strip 73 upper end has the buckle body 74 that links to each other with the constant head tank 34 joint of filter support body 3 lower extreme. The latch 74 is made of plastic material and has elasticity to facilitate the assembly and disassembly.

Preferably, an upper annular sealing inclined plane 35 is arranged between the circumferential outer side of the upper end of the filter frame body 3 and the circumferential outer side of the upper sealing plate 33, the upper annular sealing inclined plane 35 and the circumferential inner side of the upper end of the filter housing 1 are sealed, an upper sealing ring groove 36 positioned below the upper annular sealing inclined plane 35 is arranged on the circumferential outer side of the upper end of the filter frame body 3, the lower end of the guide seat 62 is flush with the lower end of the lower sealing plate 22, a lower annular sealing inclined plane 64 is arranged on the circumferential outer side of the lower end of the guide seat 62, the circumferential inner side of the lower annular sealing inclined plane 64 and the circumferential inner side of the lower end of the filter housing 1 are. The upper annular sealing inclined plane 35 and the upper sealing ring groove 36 are arranged to prevent water in the raw water cavity 4 from being directly discharged from the water outlet 12 without being filtered, and the lower annular sealing inclined plane 64 and the lower sealing ring groove 65 are arranged to prevent water in the raw water cavity 4 from directly entering the diversion cavity 63 without being filtered by the filter screen 31.

In more detail, the upper housing 13 and the lower housing 14 are connected by a screw thread, and the filter housing 1 is in a spindle-shaped structure with a thick middle and thin two ends, and the upper housing 13 has a plurality of upper concave surfaces 131 arranged along the vertical direction in the circumferential direction, and the lower housing 14 has a plurality of lower concave surfaces 141 arranged in a spiral distribution in the circumferential direction. The spindle-shaped structure can increase the water capacity of the filter housing 1.

The principle of the embodiment is as follows: through set up filter screen 31 and filter container 2 at filter housing 1 and make the water that gets into in former water cavity 4 loop through one-level filtering chamber 5 and second grade filter chamber 21, filter many times quality of water, the filter effect is good, and utilize annular water conservancy diversion structure 6 to make the rivers that pass through one-level filtering chamber 5 get into water conservancy diversion chamber 63, then get into second grade filter chamber 21 from the filter container bottom, make the filtering material in the second grade filter chamber 21 obtain utilizing to the maximize, the utilization ratio of drainage material has effectively been improved.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications, additions and substitutions for the specific embodiments described herein may be made by those skilled in the art without departing from the spirit of the invention or exceeding the scope of the invention as defined in the accompanying claims.

Although the terms of the filter housing 1, the water inlet 11, the water outlet 12, the upper housing 13, the lower housing 14, the upper concave surface 131, the lower concave surface 141, the filter container 2, the secondary filter chamber 21, the lower sealing plate 22, the lower through hole 221, the connecting cylinder 23, the annular step 24, the filter frame body 3, the filter screen 31, the through hole 32, the upper sealing plate 33, the through hole 331, the positioning groove 34, the upper annular sealing inclined surface 35, the upper sealing ring groove 36, the raw water chamber 4, the primary filter chamber 5, the annular flow guide structure 6, the connecting strip 61, the flow guide seat 62, the flow guide chamber 63, the lower annular sealing inclined surface 64, the lower sealing ring groove 65, the snap-fit positioning structure 7, the annular positioning ring 71, the positioning step 72, the positioning strip 73, the snap-fit body 74, the annular flow guide assembly 8, the flow guide channel 81, and the like are used more frequently. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed in a manner that is inconsistent with the spirit of the invention.

Claims (10)

1. The utility model provides a leading filter with dual filtering capability, is including filtering casing (1) that has the inner chamber, filtering casing (1) one side water inlet (11) have, just filtering casing (1) upper end have delivery port (12) and the lower extreme is sealed, its characterized in that, filtering casing (1) be equipped with be located the inner chamber and be hollow filtration container (2), just filtration container (2) upper end and filtration casing (1) upper end inboard circumference sealed, lower extreme and filtration casing (1) lower extreme inboard circumference sealed, and filter frame body (3) cover is equipped with in filtration container (2) circumference outside, just filtration frame body (3) circumference have filter screen (31), just filtering casing (1) circumference inboard and filter screen (31) circumference outside between form former water cavity (4) that are linked together with water inlet (11), and filter screen (31) circumference inboard and filter container (2) circumference outside between form primary filter chamber (5) that are linked together with former water cavity (4), and have secondary filter chamber (21) that are used for placing filtering material in filter container (2), secondary filter chamber (21) upper end be linked together with delivery port (12), just secondary filter chamber (21) lower extreme be linked together through annular water conservancy diversion structure (6) and primary filter chamber (5).

2. The prefilter with a double filtration function according to claim 1 wherein said filter housing (1) is of a split structure and is formed by an upper housing (13) and a lower housing (14) which are detachably connected, said water inlet (11) and said water outlet (12) are both disposed on the upper housing (13), said lower housing (14) is closed at its lower end, and said upper end of said filter container (2) and said upper end of said upper housing (13) are circumferentially sealed at their inner sides, and said lower end of said lower housing (14) are circumferentially sealed at their inner sides.

3. The prefilter with a dual filter function according to claim 2 wherein said filter container (2) is cylindrical and said filter container (2) has an open upper end, and has a lower closing plate (22) with a plurality of lower through holes (221) at its lower end, and said filter frame body (3) is cylindrical with a plurality of through holes (32) in its circumferential direction, said filter frame body (3) is coaxially sleeved on the circumferential outer side of said filter container (2), said upper end of said filter frame body (3) is provided with an upper closing plate (33) capable of closing the open upper end of said filter container (2) and having a plurality of upper through holes (331), and said lower end of said filter frame body (3) is connected to the lower end of said filter container (2) by means of a snap-fit positioning structure (7).

4. The prefilter with a dual filtration function according to claim 3 wherein the lower end of the filter frame body (3) extends to the lower end of the filter container (2), the filter screen (31) is sleeved on the circumferential outer side of the filter frame body (3) and the filter screen (31) covers the outer side face or partial outer side face of the whole filter frame body (3), and the annular flow guide structure (6) is arranged between the lower end of the filter container (2) and the lower end of the filter frame body (3).

5. The prefilter having a double filtration function according to claim 3 or 4 wherein said filter vessel (2) has at its lower end a connection cylinder (23) coaxially connected to said filter vessel (2), and said connection cylinder (23) has a diameter smaller than that of said filter vessel (2), and an annular step (24) is formed between the circumferential outer side of the upper end of said connection cylinder (23) and the circumferential outer side of said filter vessel (2), and said lower closure plate (22) is provided at the lower end of said connection cylinder (23).

6. The prefilter with a dual filter function according to claim 5 wherein the annular flow guide structure (6) comprises a plurality of connecting strips (61) which are arranged on the circumferential outer side of the connecting cylinder (23) and extend axially along the connecting cylinder (23), the outer sides of the connecting strips (61) do not exceed the outer side of the filter container (2), one end of each connecting strip (61) extends to the annular step (24), the other end of each connecting strip extends to the circumferential outer side of the lower sealing plate (22) at the lower end of the connecting cylinder (23), the circumferential outer side at the lower end of the connecting cylinder (23) is provided with a flow guide seat (62) which is coaxially arranged with the connecting cylinder (23) and is connected with the circumferential outer side at the lower end of each connecting strip (61), and the lower ends of the flow guide seat (62) and the lower sealing plate (22) and the bottom of the filter casing (1) together form a flow guide cavity (63), the flow guide cavity (63) is communicated with the secondary filter cavity (21) through a lower through hole (221), and the flow guide cavity (63) is communicated with the primary filter cavity (5) through an annular flow guide assembly (8).

7. The prefilter with a double filtration function according to claim 6 wherein the annular flow guide assembly (8) comprises a flow guide channel (81) arranged between the circumferential inner side of the flow guide seat (62) and the circumferential outer side of the lower end of the connecting cylinder (23) and between any two adjacent connecting strips (61), and one end of the flow guide channel (81) is communicated with the primary filter cavity (5), and the other end is communicated with the flow guide cavity (63).

8. The prefilter with a dual-filtration function according to claim 6, wherein the clamping positioning structure (7) comprises an annular positioning ring (71) arranged on the circumferential outer side of the upper end of the flow guide seat (62), the lower end of the filter frame body (3) is sleeved on the circumferential outer side of the annular positioning ring (71), the lower end of the filter frame body (3) abuts against a positioning step (72) arranged between the annular positioning ring (71) and the flow guide seat (62), the upper end of the annular positioning ring (71) is provided with a plurality of positioning strips (73) which are circumferentially distributed, and the upper end of each positioning strip (73) is provided with a clamping body (74) which is connected with a positioning groove (34) at the lower end of the filter frame body (3) in a clamping manner.

9. The prefilter having a dual filtration function according to claim 6, an upper annular sealing inclined plane (35) is arranged between the circumferential outer side of the upper end of the filter frame body (3) and the circumferential outer side of the upper sealing plate (33), the upper annular sealing inclined plane (35) is sealed with the circumferential inner side of the upper end of the filtering shell (1), and the circumferential outer side of the upper end of the filter frame body (3) is provided with an upper sealing ring groove (36) positioned below the upper annular sealing inclined plane (35), the lower end of the flow guide seat (62) is flush with the lower end of the lower sealing plate (22), the circumferential outer side of the lower end of the flow guide seat (62) is provided with a lower annular sealing inclined surface (64), the lower annular sealing inclined plane (64) is sealed with the circumferential inner side of the lower end of the filtering shell (1), and the circumferential outer side of the flow guide seat (62) is provided with a lower sealing ring groove (65).

10. The prefilter with a double filtration function according to claim 2 wherein said upper casing (13) and said lower casing (14) are connected by screw threads, and said filter casing (1) is of a spindle-shaped structure with a thick middle and thin ends, and said upper casing (13) has a plurality of upper concave surfaces (131) arranged along the vertical direction in the circumferential direction, and said lower casing (14) has a plurality of lower concave surfaces (141) arranged in a spiral distribution in the circumferential direction.

Images