CN113262548B

CN113262548B - Efficient flocculate separating device for chemical sewage treatment

Info

Publication number: CN113262548B
Application number: CN202110613792.XA
Authority: CN
Inventors: 王翠琼
Original assignee: Changsha Medical University
Current assignee: Changsha Medical University
Priority date: 2021-06-02
Filing date: 2021-06-02
Publication date: 2023-04-07
Anticipated expiration: 2041-06-02
Also published as: CN113262548A

Abstract

The invention relates to the field of chemical sewage treatment equipment, in particular to a floc high-efficiency separation device for chemical sewage treatment, which comprises a base and a vertical plate fixed on the base, wherein a filtering mechanism for filtering flocs from waste water after reaction is arranged on the base, a cleaning mechanism for automatically cleaning the filtering mechanism is arranged in the filtering mechanism, the filtering mechanism is in transmission connection with the cleaning mechanism, a back flushing mechanism for back flushing the filtering mechanism is arranged on the base, and the filtering mechanism is in transmission connection with the back flushing mechanism. This kind of flocculate high-efficient separator that chemical sewage treatment used filters the separation through the flocculation thing of filter mechanism in the styrene-butadiene rubber waste water after adding the medicament and reacting, and it is long when reducing the process, improves sewage treatment work efficiency, and the clean mechanism of filter mechanism drive cleans the inside wall of cartridge filter when filterable, improves cartridge filter efficient filtration efficiency, improves the collection efficiency to the flocculation thing moreover, reduces intensity of labour.

Description

Efficient flocculate separating device for chemical sewage treatment

Technical Field

The invention relates to the field of chemical sewage treatment equipment, in particular to a floc high-efficiency separation device for chemical sewage treatment.

Background

The treatment process of the waste water of the styrene butadiene rubber usually adopts a Fenton reagent method to purify the waste water, so after reagents such as coagulant, coagulant aid and the like are added for reaction, a large amount of flocculate appears in the waste water, the existing separation of the flocculate adopts a precipitation mode to separate from the water, the time consumption is long, the working efficiency is low, the waste water treatment time cost is high, the flocculate needs to be cleaned from the bottom of a precipitation tank after clear water is discharged, the labor intensity is high, the process is complicated, and therefore, the high-efficiency flocculate separation device for the chemical sewage treatment is provided.

Disclosure of Invention

The invention aims to provide a high-efficiency flocculate separating device for chemical sewage treatment, which solves the problems in the background technology. In order to achieve the purpose, the invention provides the following technical scheme: the utility model provides a flocculate high-efficient separator that chemistry sewage treatment used, includes the base and fixes the riser on the base, be provided with the filtering mechanism who is used for filtering flocculate to the waste water after the reaction on the base, the inside clean mechanism that is used for carrying out self-cleaning to filtering mechanism that is provided with of filtering mechanism, and filtering mechanism and clean mechanism transmission are connected, be provided with the recoil mechanism that is used for carrying out the backflushing to filtering mechanism on the base, and filtering mechanism and recoil mechanism transmission are connected.

Preferably, the filtering mechanism comprises a fluted disc, a first rotating shaft is vertically and fixedly connected to the center of the fluted disc, a fixed shaft of the rotating shaft is rotatably connected to the vertical plate and is in transmission connection with the motor, a second connecting rod is vertically and fixedly connected to the first rotating shaft, one end, far away from the first rotating shaft, of the second connecting rod is hinged to one end of the first connecting rod, and the first connecting rod is in transmission connection with the cleaning mechanism and the backflushing mechanism respectively.

Preferably, the filtering mechanism still includes the cartridge filter, clean mechanism sets up the inboard at the cartridge filter, the equal opening in both ends of cartridge filter sets up, and the central axis of cartridge filter and the central axis mutually perpendicular of pivot one, the both ends opening inboard of cartridge filter dead axle rotation respectively is connected with end plate one and end plate two, the lower extreme of end plate one and end plate two is fixed respectively on the support, and the support is fixed on the base, the one end that the cartridge filter lateral wall is close to end plate two cup joints and fixed connection ring gear, the ring gear is connected with the fluted disc meshing.

Preferably, the first end plate penetrates through and is fixedly connected with a liquid inlet pipe, the outlet end of the liquid inlet pipe is located on the inner side of the filter cylinder, a water receiving hopper is arranged on the lower side of the filter cylinder and is fixed on the support, the lower end of the water receiving hopper is fixed and communicated with the water drainage pipe, and the backflushing mechanism is communicated with the water drainage pipe.

Preferably, clean mechanism includes two parallel arrangement's fried dough twist pole, and the fried dough twist pole be in same level and be parallel to each other with the central axis of cartridge filter, the both ends of fried dough twist pole are perpendicular respectively and fixed connection is on end plate one and end plate two, overlap on the fried dough twist pole and establish and sliding connection have the lantern ring, two the lantern ring is the both ends of fixed connection axostylus axostyle respectively.

Preferably, the second end plate is provided with a strip-shaped through groove, the strip-shaped through groove is vertical, one end of the first connecting rod, far away from the second connecting rod, penetrates through the strip-shaped through groove and is rotatably connected with the fixed shaft of the shaft lever, and the first connecting rod can slide in the strip-shaped through groove.

Preferably, the vertical stand that upwards sets up is fixed with to the lateral wall upper end of the lantern ring, the upper end dead axle of stand rotates and is connected with pivot two, and pivot two is parallel to each other with the central axis of cartridge filter, be fixed with the brush roll on the pivot two, the brush roll is used for cleaning the inside wall of cartridge filter, the through-hole has been seted up on the end plate one, belt conveyor has passed in the through-hole, and belt conveyor's one end is located the inboard of crossing the cartridge filter and is located the downside of brush roll.

Preferably, the fixed shaft is rotatably connected with a disc on the lantern ring, the disc and the lantern ring are coaxially arranged, the twist rod penetrates through and is connected to the center of the disc in a sliding mode, and the disc is in transmission connection with the rotating shaft through the belt wheel assembly.

Preferably, the recoil mechanism comprises a cylinder fixed on the base, a piston plate is slidably connected in the cylinder, the upper surface of the piston plate is vertical and fixedly connected with a pressing rod, an upper end fixed shaft of the pressing rod is rotatably connected to the outer side wall of the sliding sleeve, and the sliding sleeve is sleeved and slidably connected to the first connecting rod.

Preferably, the support is fixed with the shunt tubes, a plurality of water nozzles are fixed and communicated on the shunt tubes, the spraying directions of the water nozzles point to the outer side wall of the filter cylinder, the cylinder barrel is respectively communicated with the shunt tubes and the drain pipe through a first water pipe and a second water pipe, the first water pipe and the second water pipe are respectively connected with a first check valve and a second check valve, the conduction direction of the first check valve points to the shunt tubes, and the conduction direction of the second check valve points to the cylinder barrel.

Compared with the prior art, the invention has the beneficial effects that:

in the invention, flocs in the styrene butadiene rubber wastewater after the reagents are added and reacted are filtered and separated by the filtering mechanism, the separation efficiency is improved, the working procedure duration is reduced, the sewage treatment working efficiency is improved, the filtering mechanism drives the cleaning mechanism to clean the inner side wall of the filter cylinder during filtering, the filter cylinder is prevented from being blocked after the flocs are accumulated, the filtering effect of the filter cylinder is ensured to be kept all the time, the efficient filtering efficiency of the filter cylinder is further improved, the collecting efficiency of the flocs is improved, the labor intensity is reduced, and the filtering mechanism drives the backflushing mechanism to perform backflushing on the filtering holes on the filter cylinder from the outer side wall of the filter cylinder at the same time, so that the efficient filtering efficiency of the filter cylinder is favorably kept.

Drawings

FIG. 1 is a schematic cross-sectional view of the final assembly of the present invention;

FIG. 2 is an enlarged schematic view of the structure at A in FIG. 1;

FIG. 3 is a left side view of the connection structure of the thimble and the twist bar in the present invention;

fig. 4 is a left side view of the second end plate structure of the present invention.

In the figure: 1. a base; 2. a vertical plate; 3. a support; 4. a water receiving hopper; 5. a liquid inlet pipe; 6. a twisted rod; 7. a belt conveyor; 8. a through hole; 9. a first end plate; 10. a filter cartridge; 11. a brush roll; 12. erecting a frame; 13. a ring gear; 14. a second end plate; 15. a sliding sleeve; 16. a first connecting rod; 17. a fluted disc; 18. a second connecting rod; 19. a first rotating shaft; 20. a strip-shaped through groove; 21. a pressure lever; 22. a piston plate; 23. a first water pipe; 24. a one-way valve I; 25. a cylinder barrel; 26. a water pipe II; 27. a second one-way valve; 28. a drain pipe; 29. a water spray nozzle; 30. a shunt tube; 31. a collar; 32. a shaft lever; 33. a disc; 34. a pulley assembly; 35. and a second rotating shaft.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by workers skilled in the art without any inventive work based on the embodiments of the present invention, are within the scope of the present invention.

Referring to fig. 1 to 4, the present invention provides a technical solution: the utility model provides a flocculate high-efficient separator that chemistry sewage treatment used, includes base 1 and fixes riser 2 on base 1, be provided with the filtering mechanism who is used for filtering flocculate to the waste water after the reaction on the base 1, the inside clean mechanism that is used for carrying out self-cleaning to filtering mechanism that is provided with of filtering mechanism, and filtering mechanism and clean mechanism transmission are connected, be provided with the recoil mechanism that is used for carrying out the backflushing to filtering mechanism on the base 1, and filtering mechanism and recoil mechanism transmission are connected.

In this embodiment, the filter mechanism includes fluted disc 17, perpendicular and fixedly connected with pivot one 19 of central department of fluted disc 17, pivot one 19 dead axle rotates to be connected on riser 2, and pivot one 19 is connected with motor drive, and the motor is not drawn in this application, perpendicular and fixedly connected with connecting rod two 18 on the pivot one 19, the one end that pivot one 19 was kept away from to connecting rod two 18 is articulated with the one end of connecting rod one 16, connecting rod one 16 is connected with clean mechanism and recoil mechanism transmission respectively.

In this embodiment, the filter mechanism still includes filter cartridge 10, clean mechanism sets up the inboard at filter cartridge 10, the equal opening in both ends of filter cartridge 10 sets up, and the central axis of filter cartridge 10 and the central axis mutually perpendicular of a 19 of pivot, the both ends opening inboard of filter cartridge 10 is dead axle rotation respectively and is connected with end plate one 9 and end plate two 14 to filter cartridge 10 is sealed with the junction of end plate one 9 and end plate two 14 and is handled, avoids the seepage, the lower extreme of end plate one 9 and end plate two 14 is fixed respectively on support 3, and support 3 fixes on base 1, the one end that the filter cartridge 10 lateral wall is close to end plate two 14 cup joints and fixed connection ring gear 13, ring gear 13 is connected with fluted disc 17 meshing.

In this embodiment, the first end plate 9 is penetrated through and fixedly connected with the liquid inlet pipe 5, an outlet end of the liquid inlet pipe 5 is located on an inner side of the filter cartridge 10, a water receiving bucket 4 is arranged on a lower side of the filter cartridge 10, the water receiving bucket 4 is fixed on the support 3, a lower end of the water receiving bucket 4 is fixed and communicated with the drain pipe 28, and the backflushing mechanism is communicated with the drain pipe 28.

In this embodiment, the cleaning mechanism includes two twist bars 6 arranged in parallel, and the twist bars 6 are at the same level and parallel to each other with the central axis of the filter cartridge 10, two ends of the twist bars 6 are respectively perpendicular and fixedly connected to the first end plate 9 and the second end plate 14, the twist bars 6 are sleeved and slidably connected with lantern rings 31, and the lantern rings 31 are respectively fixedly connected to two ends of the shaft lever 32.

In this embodiment, the second end plate 14 is provided with a strip-shaped through groove 20, the strip-shaped through groove 20 extends vertically, one end of the first connecting rod 16, which is far away from the second connecting rod 18, passes through the strip-shaped through groove 20 and is connected with the shaft rod 32 in a fixed-axis rotation manner, and the first connecting rod 16 can slide in the strip-shaped through groove 20.

In this embodiment, the vertical upright 12 that upwards sets up is fixed with to the lateral wall upper end of lantern ring 31, the upper end dead axle of upright 12 rotates and is connected with two 35 of pivot, and two 35 of pivot are parallel to each other with the central axis of cartridge filter 10, be fixed with brush roll 11 on two 35 of pivot, brush roll 11 is used for cleaning the inside wall of cartridge filter 10, through-hole 8 has been seted up on the end plate 9, belt conveyor 7 has passed in the through-hole 8, and belt conveyor 7's one end is located and passes the inboard of cartridge filter 10 and is located the downside of brush roll 11.

In this embodiment, a disk 33 is rotatably connected to the collar 31 in a fixed-axis manner, the disk 33 and the collar 31 are coaxially arranged, the twist rod 6 penetrates through and is slidably connected to the center of the disk 33, and the disk 33 is in transmission connection with the second rotating shaft 35 through a belt pulley assembly 34.

In this embodiment, the recoil mechanism includes a cylinder 25 fixed on the base 1, the piston plate 22 is slidably connected in the cylinder 25, the upper surface of the piston plate 22 is perpendicular and fixedly connected with the pressing rod 21, the upper end fixed shaft of the pressing rod 21 is rotatably connected to the outer side wall of the sliding sleeve 15, and the sliding sleeve 15 is sleeved and slidably connected to the first connecting rod 16.

In this embodiment, a diversion pipe 30 is fixed on the support 3, a plurality of water nozzles 29 are fixed on the diversion pipe 30 and communicated with the diversion pipe 30, the spraying directions of the water nozzles 29 point to the outer side wall of the filter cartridge 10, the cylinder barrel 25 is respectively communicated with the diversion pipe 30 and the water discharge pipe 28 through a first water pipe 23 and a second water pipe 26, the first water pipe 23 and the second water pipe 26 are respectively connected with a first check valve 24 and a second check valve 27, the conduction direction of the first check valve 24 points to the diversion pipe 30, and the conduction direction of the second check valve 27 points to the cylinder barrel 25.

The use method and the advantages of the invention are as follows: when the floc high-efficiency separation device for treating chemical sewage is used, the working process is as follows:

as shown in fig. 1, the starting motor and the belt conveyor 7 work, the waste water of the styrene butadiene rubber added with the chemicals and reacted through the liquid inlet pipe 5 is conveyed to the inside of the filter cylinder 10 through the liquid inlet pipe 5, the flocculate is left on the inner side wall of the filter cylinder 10 through the filtration of the filter cylinder 10, and the clear water is discharged through the filtering hole of the filter cylinder 10 and falls into the water receiving hopper 4, and then is discharged through the drain pipe 28, thereby realizing the separation of the flocculate, improving the separation efficiency, reducing the working procedure duration, and improving the working efficiency of sewage treatment.

Drive a pivot 19 after the motor work and rotate, make a 19 synchronous driving fluted disc 17 of pivot rotate, fluted disc 17's rotation drives ring gear 13 through the tooth transmission effect between the remaining ring gear 13 of fluted disc 17 and rotates, thereby make ring gear 13 drive cartridge filter 10 in step rotate, cartridge filter 10's rotation makes cartridge filter 10's inside wall circulation be in the exit end downside of feed liquor pipe 5, and then avoid the flocculate to be in the same position of cartridge filter 10's inside wall, lead to the flocculate to pile up the inside wall that blocks up cartridge filter 10 after, thereby ensure to remain cartridge filter 10's filter effect all the time, and then improve cartridge filter 10 efficient filtration efficiency.

The first rotating shaft 19 rotates and simultaneously drives the second connecting rod 18 to rotate, so that the second connecting rod 18 applies a pulling force or a pushing force to the shaft rod 32 through the first connecting rod 16, as shown in fig. 1, fig. 2 and fig. 3, so that the shaft rod 32 synchronously drives the two lantern rings 31 to perform reciprocating sliding on the corresponding twist rod 6 along the length direction of the twist rod 6, and further the lantern rings 31 synchronously drive the vertical frame 12 to perform reciprocating sliding along the length direction of the twist rod 6, the vertical frame 12 synchronously drives the brush roll 11 through the second rotating shaft 35 to clean flocs on the inner side wall of the filter cartridge 10 while performing sliding, so that the inner side wall of the filter cartridge 10 is kept from being blocked by the flocs, efficient filtering efficiency is always kept, and the flocs cleaned by the brush roll 11 fall on the belt conveyor 7, and is carried to the outside of cartridge filter 10 by belt conveyor 7, thereby realize collection and the output to the flocculation thing, need not manual operation, reduce intensity of labour, improve work efficiency, and can go on simultaneously with the separation of flocculation thing, the simplified procedure, reduce the process length, the rotation of cartridge filter 10 makes the inner wall region after the brush roll 11 is clean remove to the exit end department of feed liquor pipe 5, so that make cartridge filter 10 efficient filter region filter the flocculation thing in the waste water, keep efficient filtration efficiency and effect, and rotate the position that has the flocculation thing with feed liquor pipe 5 exit end department simultaneously to brush roll 11 department, so that clean and collect the flocculation thing on the cartridge filter 10 inside wall, reduce intensity of labour and process length.

As mentioned above, the synchronous drive disc 33 is made reciprocating sliding along the length direction of the twist rod 6 in the sliding process of the lantern ring 31, and under the torsion action of the helicoid of the twist rod 6, the disc 33 is made to slide along the length direction of the twist rod 6 and rotate, so that the disc 33 drives the two rotating shafts 35 to rotate through the belt wheel assembly 34, and further the two rotating shafts 35 drive the brush roller 11 to rotate, thereby improving the cleaning effect and efficiency of the brush roller 11 on the inner side wall of the filter cartridge 10, ensuring that the filter cartridge 10 is not blocked by flocculates, always keeping high-efficiency filtering efficiency, and improving the collecting efficiency of the flocculates.

As shown in FIG. 1, in the process that the first connecting rod 16 applies a pulling force or a pushing force to the shaft rod 32, the sliding sleeve 15 is synchronously driven to move up and down in a reciprocating manner in the vertical direction, so that the sliding sleeve 15 applies a pulling force or a pressure to the pressing rod 21, so that the pressing rod 21 synchronously drives the piston plate 22 to move up or down, when the piston plate 22 moves down, the piston plate 22 applies a downward force to the water in the cylinder 25, so that the water pressure is increased, because the conduction direction of the first check valve 24 is directed to the diversion pipe 30, and the conduction direction of the second check valve 27 is directed to the cylinder 25, so that the high-pressure water in the cylinder 25 is conveyed into the diversion pipe 30 through the first water pipe 23 and is diverted into each water nozzle 29 by the diversion pipe 30, and then is sprayed onto the outer side wall of the filter cylinder 10 by each water nozzle 29, so that the water reversely washes the filter holes from the outer side wall of the filter cylinder 10, thereby preventing the flocculate from being blocked into the filter holes from being completely cleaned by the filter roll 11, improving the cleaning effect and efficiency of the filter cylinder 10, ensuring that the filter cylinder 10 is not blocked by the flocculate being completely cleaned by the filter holes 11, and the filter tubes 26, when the piston plate 22 moves up, thereby increasing the efficiency of the water pipe 25, and the water is maintained, and the water is conveyed to the water discharge pipe 25, and the water discharge pipe 25 is discharged from the filter tubes 28, and the filter tubes 28.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It should be understood by those skilled in the art that the present invention is not limited to the above-described embodiments, and the above-described embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. The utility model provides a high-efficient separator of flocculation thing that chemistry sewage treatment used, includes base (1) and riser (2) of fixing on base (1), its characterized in that: the base (1) is provided with a filtering mechanism for filtering flocculated waste water after reaction, the filtering mechanism is internally provided with a cleaning mechanism for automatically cleaning the filtering mechanism, the filtering mechanism is in transmission connection with the cleaning mechanism, the base (1) is provided with a backflushing mechanism for backflushing the filtering mechanism, the filtering mechanism is in transmission connection with the backflushing mechanism, the filtering mechanism comprises a fluted disc (17), the center of the fluted disc (17) is vertically and fixedly connected with a first rotating shaft (19), the first rotating shaft (19) is in fixed shaft connection with a vertical plate (2), the first rotating shaft (19) is in transmission connection with a motor, the first rotating shaft (19) is vertically and fixedly connected with a second connecting rod (18), one end of the second connecting rod (18) far away from the first rotating shaft (19) is hinged with one end of the first connecting rod (16), the first connecting rod (16) is in transmission connection with the cleaning mechanism and the backflushing mechanism respectively, the filtering mechanism further comprises a filtering cylinder (10), the cleaning mechanism is arranged on the inner side of the filtering cylinder (10), openings are formed at the two ends of the filtering cylinder (10), the central axis of the first rotating shaft (10) is fixed with a first rotating shaft support (19), the first rotating shaft (14) and the lower end plate (14) and the second end plate (9) is fixed on the inner side of the filtering cylinder support (9), and support (3) are fixed on base (1), cartridge filter (10) lateral wall is close to the one end of end plate two (14) and cup joints and fixed connection ring gear (13), ring gear (13) are connected with fluted disc (17) meshing, run through and fixed connection feed liquor pipe (5) on end plate (9), and the exit end of feed liquor pipe (5) is located the inboard of cartridge filter (10), the downside of cartridge filter (10) is provided with and connects water bucket (4), connect water bucket (4) to fix on support (3), the fixed and water piping (28) that feed through of lower extreme that connects water bucket (4), recoil mechanism is linked together with drain pipe (28).

2. The apparatus of claim 1, wherein the apparatus further comprises: clean mechanism includes two parallel arrangement's fried dough twist pole (6), and fried dough twist pole (6) be in same level and be parallel to each other with the central axis of cartridge filter (10), the both ends of fried dough twist pole (6) are perpendicular respectively and fixed connection on end plate one (9) and end plate two (14), overlap on fried dough twist pole (6) and establish and sliding connection have lantern ring (31), two lantern ring (31) are the both ends of fixed connection axostylus axostyle (32) respectively.

3. The apparatus of claim 2, wherein the apparatus comprises: the connecting rod I (16) is far away from one end of the connecting rod II (18) and penetrates through the strip-shaped through groove (20) to be connected with the shaft rod (32) in a fixed-axis rotating mode, and the connecting rod I (16) can slide in the strip-shaped through groove (20).

4. The apparatus of claim 3, wherein the apparatus further comprises: the utility model discloses a filter cartridge, including lantern ring (31), the lateral wall upper end of lantern ring (31) is fixed with vertical grudging post (12) that upwards sets up, the upper end dead axle of grudging post (12) rotates and is connected with pivot two (35), and the central axis of pivot two (35) and cartridge filter (10) is parallel to each other, be fixed with brush roll (11) on pivot two (35), brush roll (11) are used for cleaning the inside wall of cartridge filter (10), through-hole (8) have been seted up on end plate (9), belt conveyor (7) have been passed in through-hole (8), and the one end of belt conveyor (7) is located the inboard of crossing cartridge filter (10) and is located the downside of brush roll (11).

5. The apparatus of claim 4, wherein the apparatus further comprises: the fixed shaft is connected with disc (33) on lantern ring (31) in a rotating mode, disc (33) and lantern ring (31) are arranged coaxially, twist rod (6) penetrates through and is connected to the center of disc (33) in a sliding mode, and disc (33) is connected with second rotating shaft (35) through belt wheel assembly (34) in a transmission mode.

6. The apparatus of claim 5, wherein the apparatus further comprises: the recoil mechanism comprises a cylinder barrel (25) fixed on the base (1), a piston plate (22) is connected in the cylinder barrel (25) in a sliding mode, the upper surface of the piston plate (22) is vertical and is fixedly connected with a pressing rod (21), the upper end fixed shaft of the pressing rod (21) is rotatably connected to the outer side wall of the sliding sleeve (15), and the sliding sleeve (15) is sleeved and is connected to the first connecting rod (16) in a sliding mode.

7. The apparatus of claim 6, wherein the apparatus comprises: be fixed with shunt tubes (30) on support (3), fixed and the intercommunication has a plurality of water jet (29) on shunt tubes (30), the lateral wall of the directional cartridge filter (10) of jet direction of water jet (29), cylinder (25) are respectively through water pipe (23) and water pipe two (26) intercommunication shunt tubes (30) and drain pipe (28), connect check valve (24) and check valve two (27) on water pipe (23) and water pipe two (26) respectively, the directional shunt tubes (30) of direction of switching on of check valve (24), the directional cylinder (25) of direction of switching on of check valve two (27).