CN112337150A - Pulse continuous sand filtering device - Google Patents

Abstract

The invention relates to a sewage advanced treatment device, in particular to a pulse continuous sand filtering device, which solves the technical problems in the background technology and comprises a filtering tower and a pulse gas-water separator, wherein the filtering tower comprises a cylinder and a lower end socket, a water distributor and a angle cone disc for removing repose are arranged in the cylinder, a sand outlet is formed in the cylinder, the sand outlet is connected with a sand outlet pipe, and a sand washer is supported in the cylinder; the top of the barrel body is provided with a clean water tank, a sand washing tank is arranged above the sand washer, a backwashing water outlet is arranged on the sand washing tank, the filter tower comprises a sand lifting pipe, one end of the sand lifting pipe is arranged in the sand washing tank, a sand blasting ejector is arranged on the body of the sand lifting pipe, and the sand outlet pipe is communicated with the sand lifting pipe through the sand blasting ejector; the pulse gas-water separator is provided with a gas phase outlet and a liquid phase outlet, the gas phase outlet is connected with the other end of the sand extracting pipe, the liquid phase outlet is connected with a water distributor of the filter tower, and the gas phase pipe and the liquid phase pipe are both provided with one-way valves. The device realizes the continuous water filtering function and the sand filtering and backwashing function without external air power.

Description

Pulse continuous sand filtering device

Technical Field

The invention relates to a sewage advanced treatment device, in particular to a pulse continuous sand filtering device.

Background

In advanced sewage treatment, various types of rapid filters have been widely used which retain suspended solids in water by utilizing the surface area provided by the granular material in the filter bed. The operation of most rapid filters is that two processes of filtering and backwashing are circularly and alternately carried out. The filtration is a process for producing clear water, the sewage to be treated passes through a filter layer from top to bottom or from bottom to top in the filter tank, and after the sewage is adsorbed and trapped by the filter layer, the clear water is collected and flows out of the filter tank. During the working period, the filter tank is in a full immersion state. After a period of filtration, the filter material layer is blocked by suspended matters, the water flow resistance is continuously increased, when the head loss of the filter layer is increased to the maximum allowable value or the filtered water quality is close to the standard exceeding, the filter tank stops running and performs backwashing. The back washing water is generally supplied by a washing water tank or a washing water pump, a water inlet pipe and a clear water branch pipe are closed, a drain valve and a back washing water pipe are opened, the back washing water reversely passes through a filter material layer from bottom to top or from top to bottom with a normal filtering flow, and is collected and discharged by a back washing water discharge tank. After the filter is back washed, the filtering and dirt-intercepting capacity is recovered, and the filter can be put into operation again. The filtration period between two backwashes is generally 8-12 hours, and the backwashing duration is generally about 12 minutes.

However, in the actual operation process, two main limiting factors are provided, namely the maintenance of the operation and backwashing switching valve group and the human factor of the process operation. These two factors can affect the operation cycle or the effluent quality, and the contradiction is increasingly prominent under the condition that the environmental protection situation is increasingly severe.

Although the technology of the environmental protection industry is rapidly developed, some standards about filter materials are established, a multi-layer filter tank is selected, and the like, and even foreign continuous sand filters are introduced in the 80 s of the 20 th century, the defects of high cost, high energy consumption, large maintenance amount, large artificial factors of process operation and the like exist. Therefore, the continuous sand filtration technique introduced from abroad is not widespread. The main reasons are that the structure is complex, the cost is high, a large-scale air compressor is required to be arranged, and the energy consumption is high.

Therefore, it is necessary to design a sand filter device with high efficiency, low energy consumption, reduced maintenance workload and avoiding human operation factors, aiming at the defects of the prior sand filter device.

Disclosure of Invention

The invention aims to solve the technical problems of overhigh cost, high energy consumption, high maintenance cost or large factors considered by process operation of the conventional sewage advanced treatment device, and provides a pulse continuous sand filtering device.

The technical means for solving the technical problems of the invention is as follows:

a pulse continuous sand filtering device comprises a filtering tower and a pulse gas-water separator, wherein the filtering tower comprises a barrel and a lower end socket connected to the lower end of the barrel, a water distributor is horizontally arranged in the lower part of the barrel, a repose angle cone disc is supported between barrel walls of the barrel below the water distributor, a sand outlet is formed in the barrel wall of the barrel below the repose angle cone disc, a sand outlet is connected to the sand outlet in a sealing manner, a sand suction port of the sand outlet extends to the position near the bottom of the lower end socket, a sand washer is supported in the upper part of the barrel through a support, the barrel and the lower end socket which are positioned below the sand washer are filled with filter sand, the sand washer is formed by concentrically sleeving a plurality of layers of lantern-shaped barrels with equal height, a sand falling gap is formed between the barrel walls of adjacent lantern-shaped barrels, and the top and the bottom of the lantern-shaped barrel are fixedly connected with blocking rods for connecting all the lantern-shaped barrels; the outer side of the top of the barrel is circumferentially provided with a clean water tank, a sand washing tank communicated with the sand washer is arranged above the sand washer, the top of the sand washing tank is higher than the tops of the barrel and the clean water tank, a backwashing water outlet is arranged on the sand washing tank, the filter tower further comprises a sand lifting pipe, one end of the sand lifting pipe is arranged in the sand washing tank, a sand blasting ejector is arranged on the pipe body of the sand lifting pipe, and the end outside the sand outlet pipe is communicated with the sand lifting pipe through the sand blasting ejector; the pulse gas-water separator is connected with a sewage inlet pipeline, the sewage inlet pipeline is provided with an air ejector for sucking air, the top and the bottom of the pulse gas-water separator are respectively provided with a gas phase outlet and a liquid phase outlet, the gas phase outlet is communicated with the other end of the sand extracting pipe through a gas phase pipe, the liquid phase outlet is connected with a water distributor of the filter tower through a liquid phase pipe, and the gas phase pipe and the liquid phase pipe are respectively provided with a one-way valve with certain starting pressure.

The water distributor can ensure that water inlet is uniformly distributed, the anti-settling cone disc is arranged to remove sand filter to naturally stack the settling angle, the anti-settling cone disc can ensure that water filter can uniformly pass through, the sand outlet pipe at the bottom of the tower cannot be pressed by sand filter, and the normal operation of a sand shooting process is ensured, the sand washer is a plurality of layers of lantern-shaped cylinders with the same height, adjacent lantern-shaped cylinders keep a certain interval to form a sand falling gap, water can penetrate through the sand washer from bottom to top, the sand filter can also penetrate through the sand washer from top to bottom, the water and the sand filter are in turnover contact between the adjacent lantern-shaped cylinders, the sand filter is further cleaned, the flushing effect of the sand filter is ensured, the air ejector sucks air through sewage jet with pressure, the technology is mature technology, the technology of sucking air by the air ejector is applied, the configuration of a large air compressor in the sand lifting process can be omitted, the cost is saved, and the energy consumption is saved, the maintenance step of the large air compressor is omitted, and labor and cost are saved; the power source of the sand blasting ejector is gas from a pulse gas-water separator. The pulse frequency of the pulse gas-water separator is determined by the starting pressure of the one-way valves on the gas phase pipe and the liquid phase pipe. The sewage flowing out of the pulse gas-water separator is connected to the filter tower through the liquid phase pipeline to be filtered through the sand filter, the gas discharged from the pulse gas-water separator drives the sand filter to be conveyed into the sand washing tank and the sand washer from the sand lifting pipe to be washed, the circulation of water filtering and sand washing enables the whole equipment to run all the time, the maintenance cost is saved, full-automatic continuous pulse operation is realized, and the sand filtering efficiency of sewage deep treatment is greatly improved.

The working principle of the pulse continuous sand filtering device is as follows: the sewage with pressure enters the pulse gas-water separator from a sewage inlet pipeline, the gas enters the pulse gas-water separator along with an air jet device, then the gas and the liquid are separated in the pulse gas-water separator, the gas is discharged from a gas phase outlet through a gas phase pipe, the sewage is uniformly discharged from a liquid phase outlet through a liquid phase pipe from a water distributor in a filter tower, the sewage flows downwards firstly, after a cylinder body and a lower end enclosure below the water distributor are full, the sewage flows upwards gradually, the sewage passes through sand filtering, the sand filtering passes through the space outside a sand washer and inside the cylinder body, overflows from the top of the cylinder body to a clear water tank and is discharged from the clear water tank, for example, the clear water tank is extracted and discharged through a pipeline, the gas of the pulse gas-water separator is connected with a sand lifting pipe through the gas phase pipe, under the action of the sand jet device, the sand filtering sand in the lower end enclosure near a sand suction port is sucked out and lifted from the sand lifting pipe to the sand, clear water passing through the sand filter rises from the bottom of the sand washer, the sand filter is in tumbling contact with cleaning water filter rising in a reverse pulse mode by virtue of a dead weight falling process, the sand filter is further cleaned, the sand filter flushing effect is ensured, the sand filter falls in the barrel by virtue of dead weight after being cleaned, water filtering is continued, sewage for cleaning the sand filter continues to rise and is discharged from a backwashing water outlet of the sand washing tank, the whole cleaning process is circularly repeated, the filter tank does not need to stop running, backwashing and water filtering are simultaneously carried out, the complex pipeline structure and the operation of a switching valve are avoided, the maintenance of the switching valve is avoided, the process is simple, the influence of artificial operation factors on a water filtering system is avoided, the operation period and the effluent water quality are ensured, high-cost equipment caused by the introduction is not needed, and unnecessary energy consumption is reduced.

Preferably, the liquid phase pipe positioned outside the liquid phase outlet is arranged into a U-shaped pipe section which enables the bottom of the pulse gas-water separator to form a water seal. The water seal with proper height is reserved to ensure that the gas phase in the pulse gas-water separator does not flow into the liquid phase pipe and ensure the stability of sand blasting.

Preferably, the lowest point of the liquid phase pipe is also provided with a sewage discharge pipe opening, and the sewage discharge pipe opening is provided with a stop valve. The liquid phase pipe is subjected to pollution discharge treatment after a certain time, the smoothness of the liquid phase pipe is guaranteed, and the filter tower is further guaranteed to filter smoothly.

Preferably, the sand extracting pipe stretches out the bottom of the back vertical downwardly extending to the filter tower from the sand washing groove, the sand blasting ejector is horizontally arranged opposite to the sand outlet, the sand extracting pipe is connected with the gas phase pipe and then downwardly extends to form a tail end pipe, and a stop valve is arranged on the tail end pipe. This is in order to regularly clear up and switch on the sand lifting pipe, convenient maintenance and overhaul.

Preferably, the angle-removing cone disc is a cone disc with the tip upwards, and the angle of the cone disc is equal to the natural stacking angle of the filter sand. This is to ensure the filter section of the filter sand to be of equal thickness dynamically.

Preferably, the stop rods at the top and the bottom of the lantern-shaped cylinder are in a cross shape, so that the lantern-shaped cylinder is connected more firmly, and the sand washer is stable in structure.

Preferably, a reinforced supporting structure is arranged between the bottom of the clean water tank and the outer wall of the cylinder body. This is for the structure to be more stable and reasonable.

Preferably, the outside of the lower head is provided with a supporting leg for supporting the filtration tower. This is for the structure to be more stable and reasonable.

The invention has the beneficial effects that: the device has the advantages of reasonable structure, convenient operation, no external air power supply is realized in a real sense, the water filtering function and the sand filtering reverse washing function are realized, no additional energy consumption exists in the period, the pulse air-water separator is arranged, the pulse sand filtering has a more ideal filtering effect, the operation or reverse washing switching valve component is reduced to the greatest extent, a special reverse washing pump is not needed, the maintenance amount is small, the considered operation factor is avoided, the reverse washing and the filtering are carried out simultaneously, the period of stopping the filtering for realizing the reverse washing is avoided, the continuous circulating operation of the whole system is realized, the deep sewage treatment efficiency is greatly improved, the cost is saved, the energy consumption is saved, the labor cost is saved, the device has higher economic benefit, the practicability is stronger, and the device is worthy of popularization and application.

Drawings

Fig. 1 is a schematic structural diagram of a pulse continuous sand filtering device according to the present invention.

Fig. 2 is a schematic top view of the clean water tank of fig. 1 according to the present invention.

FIG. 3 is a cross-sectional view of a sand washer according to the present invention.

Fig. 4 is a top view of fig. 3.

In the figure: 1-a filtration tower; 2-pulse gas-water separator; 3-a cylinder body; 4-lower end enclosure; 5-a water distributor; 6-removing a repose angle cone disc; 7-a sand outlet; 8-a sand outlet pipe; 9-a sand sucking port; 10-a scaffold; 11-a sand washer; 12-a lantern-shaped cylinder; 13-a gear lever; 14-a sand washing tank; 16-a sand extracting pipe; 17-a clear water tank; 18-clear water outlet; 19-backwash water outlet; 20-a sewage inlet pipeline; 21-an air jet device; 22-a gas phase outlet; 23-a liquid phase outlet; 24-gas phase tube; 25-sand jet ejector; 26-a liquid phase tube; 27-a one-way valve; 28-a stop valve; 29-manhole; 30-a discharge hole; 31-support leg.

Detailed Description

A pulse continuous type sand filtering apparatus according to the present invention will be described in detail with reference to fig. 1 to 4.

A pulse continuous sand filter device is disclosed, as shown in figure 1, comprising a filter tower 1 and a pulse gas-water separator 2, wherein the filter tower 1 comprises a cylinder 3 and a lower end enclosure 4 connected with the lower end of the cylinder 3, a water distributor 5 is horizontally arranged in the lower part of the cylinder 3, a dean cone disc 6 is supported between the cylinder walls of the cylinder 3 below the water distributor 5, a sand outlet 7 is opened on the cylinder wall of the cylinder 3 below the dean cone disc 6, a sand outlet 8 is connected on the sand outlet 7 in a sealing way, a sand suction port 9 of the sand outlet 8 extends to the vicinity of the bottom of the lower end enclosure 4, a sand washer 11 is supported in the upper part of the cylinder 3 through a bracket 10, the cylinder 3 and the lower end enclosure 4 below the sand washer 11 are filled with filter sand, the sand washer 11 is formed by concentrically sleeving a plurality of layers of lantern-shaped cylinders 12 with equal height, as shown in figures 3 and 4, a sand falling gap is arranged between the cylinder walls of the adjacent lantern-shaped cylinders 12, the top and the bottom of the lantern-shaped cylinder 12 are respectively fixedly connected with a stop lever 13 used for connecting all the lantern-shaped cylinders 12; a clear water tank 17 is expanded on the outer side of the top of the barrel 3 along the circumferential direction, a clear water outlet 18 is arranged on the clear water tank 17, specifically shown in fig. 2, a sand washing tank 14 communicated with the sand washer 11 is arranged above the sand washer 11, the top of the sand washing tank 14 is higher than the tops of the barrel 3 and the clear water tank 17, a backwashing water outlet 19 is arranged on the sand washing tank 14, the filter tower 1 further comprises a sand lifting pipe 16, one end of the sand lifting pipe 16 is arranged in the sand washing tank 14, a sand blasting jet device 25 is arranged on the body of the sand lifting pipe 16, and the end head outside the sand outlet pipe 8 is communicated with the sand lifting pipe 16 through the sand blasting jet device 25; the pulse gas-water separator 2 is connected with a sewage water inlet pipeline 20, the sewage water inlet pipeline 20 is provided with an air ejector 21 for sucking air, the top and the bottom of the pulse gas-water separator 2 are respectively provided with a gas phase outlet 22 and a liquid phase outlet 23, the gas phase outlet 22 is communicated with the other end of the sand lifting pipe 16 through a gas phase pipe 24, the liquid phase outlet 23 is connected with the water distributor 5 of the filter tower 1 through a liquid phase pipe 26, and the gas phase pipe 24 and the liquid phase pipe 26 are both provided with check valves 27 with certain starting pressure. In a specific implementation, the number of layers of the lantern-shaped cylinder 12 with equal height in the sand washer 11 is determined by the inner diameter of the cylinder, and as shown in fig. 4, 5 layers can be set.

The water distributor 5 can ensure that water inlet is uniformly distributed, the sediment outlet pipe 8 at the bottom of the tower cannot be pressed by filtered sand while the sediment outlet conical disc 6 can ensure that filtered water passes through the sediment outlet conical disc 6, and the normal operation of the sand shooting process is ensured, the sand washer 11 is a plurality of layers of lantern-shaped cylinders 12 with the same height, the adjacent lantern-shaped cylinders 12 keep a certain interval, water can pass through the sand washer 11 from bottom to top, the filtered sand can also pass through the sand washer 11 from top to bottom, the water and the filtered sand are in tumbling contact between the adjacent lantern-shaped cylinders 12, the filtered sand is further cleaned, and the flushing effect of the filtered sand is ensured, wherein the air ejector 21 sucks air through sewage jet flow with pressure, which is a mature technology, the technology of sucking air by the air ejector 21 can save the configuration of a large air compressor in the sand lifting process, and save cost, the energy consumption is saved, the maintenance step of a large air compressor is omitted, and the labor and the cost are saved; the power source of the sand blasting ejector 25 is the gas from the pulse gas-water separator 2. The pulsing frequency of the pulse gas-water separator 2 is determined by the activation pressure of the check valve 27 on the gas phase pipe 24 and the liquid phase pipe 26. The sewage flowing out of the pulse gas-water separator 2 is connected to the filter tower 1 through a liquid phase pipe 26 and is filtered through the sand filter, the gas discharged from the pulse gas-water separator 2 drives the sand filter to be conveyed into the sand washing tank 14 and the sand washer 11 from the sand extracting pipe 16 for sand washing, and the whole equipment is always operated through the circulation reciprocating of water filtering and sand washing, so that the maintenance cost is saved, the full-automatic continuous pulse operation is realized, and the sand filtering efficiency of the sewage deep treatment is greatly improved. During specific operation, the position of the anti-settling angle cone disk 6 must be adjusted to a proper position, so that the sand filter leaked from the anti-settling angle cone disk 6 is ensured not to block and press a sand suction port 9 for sucking dirty sand on the bottom sand outlet pipe 8; the sewage jet pipe section of the air jet device 21 is designed to be a vertical section with a certain height, so that the strength of jet air suction is ensured. The lantern-shaped cylinder 12 may be provided as a bent cylinder as shown in fig. 3, so that a plurality of layers of baffle ring-shaped gaps are formed between the lantern-shaped cylinders 12.

The working principle of the pulse continuous sand filtering device is as follows: the sewage with pressure enters the pulse gas-water separator 2 from the sewage inlet pipeline 20, the gas enters the pulse gas-water separator 2 along with the air ejector 21, then the gas and the liquid are separated in the pulse gas-water separator 2, the gas is discharged from the gas phase outlet 22 through the gas phase pipe 24, the sewage is uniformly discharged from the liquid phase outlet 23 through the liquid phase pipe 26 from the water distributor 5 in the filter tower 1, the sewage flows downwards firstly, after the cylinder 3 and the lower end enclosure 4 below the water distributor 5 are full, the sewage flows upwards gradually, after passing through the sand filter, the sand filter passes through the space outside the sand washer 11 and inside the cylinder 3 and flows upwards from the top of the cylinder 3 to the clear water tank 17, and is discharged from the clear water tank 17, the gas of the pulse gas-water separator 2 is connected with the sand extraction pipe 16 through the gas phase pipe 24, under the action of the sand jet ejector 25, the sand filter close to the sand suction port 9 in the lower end enclosure 4 is sucked out, and lifted from the sand lifting pipe 16 to the sand washing tank 14, clear water passing through the sand filter rises from the bottom of the sand washer 11, the sand filter falls under the dead weight to be in tumble-shaped contact with clean water filter rising in a reverse pulse manner, the sand filter is further cleaned, the sand filter flushing effect is ensured, the sand filter falls in the cylinder 3 under the dead weight after being cleaned, the water filter is continuously performed, sewage for cleaning the sand filter continuously rises to be discharged from a backwashing water outlet 19 of the sand washing tank 14, the whole cleaning process is circularly repeated, the filter tank does not need to stop running, backwashing and water filtering are performed simultaneously, the complex pipeline structure and the operation of switching valves are avoided, therefore, the maintenance of the switching valve is avoided, the process is simple, the influence of artificial operation factors on a water filtering system is avoided, the operation period and the effluent quality are ensured, high-cost equipment is not required to be introduced, and unnecessary energy consumption is reduced.

Further, as a specific embodiment of the pulse continuous sand filtering apparatus according to the present invention, as shown in fig. 1, a liquid phase pipe 26 located outside the liquid phase outlet 23 is provided as a U-shaped pipe section which forms a water seal at the bottom of the pulse gas-water separator 2. The water seal with proper height is reserved to ensure that the gas phase in the pulse gas-water separator does not flow into the liquid phase pipe 26 and ensure the stability of sand blasting.

Further, as a specific embodiment of the pulse continuous sand filtering device according to the present invention, as shown in fig. 1, a drain pipe opening is further provided at the lowest point of the liquid phase pipe 26, and a stop valve 28 is provided at the drain pipe opening. The arrangement is that the liquid phase pipe 26 is subjected to pollution discharge treatment after a certain time, the smoothness of the liquid phase pipe 26 is ensured, and the filtering tower 1 is further ensured to be smoothly filtered, so that the structure is more reasonable, and the maintenance is convenient and simple.

Further, as a specific embodiment of the pulse continuous sand filtering device according to the present invention, as shown in fig. 1, the sand extracting pipe 16 extends out from the sand washing tank and then vertically extends downward to the bottom of the filtering tower 1, the sand blasting jet 25 is horizontally disposed opposite to the sand outlet 7, the sand extracting pipe 16 is connected to the gas phase pipe 24 and then further extends downward to form a terminal pipe, and the terminal pipe is provided with a stop valve 28. This is for regularly clearing up and conducting the sand extracting pipe 16, convenient maintenance is overhauld.

Further, as a specific embodiment of the pulse continuous sand filtering apparatus according to the present invention, as shown in fig. 1, the anti-repose cone 6 is a cone with its tip facing upward, and the angle of the cone is equal to the natural repose angle of the sand filter. This is to ensure the filter section of the filter sand to be of equal thickness dynamically.

Further, as an embodiment of the present invention, as shown in fig. 4, the blocking rods 13 at the top and bottom of the lantern-shaped cylinder 12 are arranged in a cross shape, so that the lantern-shaped cylinder 12 is connected more firmly, and the sand washer 11 is structurally stable.

Further, as a specific embodiment of the pulse continuous sand filtering device of the present invention, as shown in fig. 1, a reinforced supporting structure is provided between the bottom of the clean water tank 17 and the outer wall of the barrel 3. This is for a more robust, stable and rational construction.

Further, as a specific embodiment of the pulse continuous sand filtering device according to the present invention, as shown in fig. 1, a support leg 31 for supporting the filtering tower 1 is provided outside the lower head 4. This is for the structure to be more stable and reasonable.

While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

1. A pulse continuous sand filtering device is characterized by comprising a filtering tower (1) and a pulse gas-water separator (2), wherein the filtering tower (1) comprises a barrel (3) and a lower end enclosure (4) connected to the lower end of the barrel (3), a water distributor (5) is horizontally arranged in the lower part of the barrel (3), a repose angle cone disc (6) is supported between barrel walls of the barrel (3) below the water distributor (5), a sand outlet (7) is formed in the barrel wall of the barrel (3) below the repose angle cone disc (6), a sand outlet pipe (8) is hermetically connected to the sand outlet (7), a sand suction port (9) of the sand outlet pipe (8) extends to the position near the bottom of the lower end enclosure (4), a sand washer (11) is supported in the upper part of the barrel (3) through a support (10), and the barrel (3) and the lower end enclosure (4) which are positioned below the sand washer (11) are filled with filter sand, the sand washer (11) is formed by concentrically sleeving a plurality of layers of lantern-shaped cylinders (12) with equal height, sand falling gaps are arranged between the cylinder walls of the adjacent lantern-shaped cylinders (12), and the top and the bottom of each lantern-shaped cylinder (12) are fixedly connected with a stop lever (13) used for connecting all the lantern-shaped cylinders (12) respectively; a clear water tank (17) is arranged on the outer side of the top of the barrel body (3) in an expanding mode along the circumferential direction, a sand washing tank (14) communicated with the sand washer (11) is arranged above the sand washer (11), the top of the sand washing tank (14) is higher than the tops of the barrel body (3) and the clear water tank (17), a backwashing water outlet (19) is arranged on the sand washing tank (14), the filter tower (1) further comprises a sand lifting pipe (16), one end of the sand lifting pipe (16) is arranged in the sand washing tank (14), a sand blasting jet device (25) is arranged on the body of the sand lifting pipe (16), and the end outside the sand outlet pipe (8) is communicated with the sand lifting pipe (16) through the sand blasting jet device (25); be connected with sewage inlet line (20) on pulse gas-water separator (2), be provided with air jet ware (21) that is used for the inhaled air on sewage inlet line (20), the top and the bottom of pulse gas-water separator (2) are provided with gaseous phase export (22) and liquid phase export (23) respectively, gaseous phase export (22) are linked together through gaseous phase pipe (24) and the other end of carrying sand pipe (16), liquid phase export (23) are connected with water-locator (5) of filtration tower (1) through liquid phase pipe (26), all be provided with check valve (27) that have certain starting pressure on gaseous phase pipe (24) and liquid phase pipe (26).

2. A pulse train sand filter unit according to claim 1, characterised in that the liquid phase pipe (26) outside the liquid phase outlet (23) is arranged as a U-shaped pipe section which forms a water seal at the bottom of the pulse gas-water separator (2).

3. A pulse train sand filter as claimed in claim 1, wherein a waste pipe opening is provided at the lowest point of the liquid phase pipe (26), and a shut-off valve (28) is provided at the waste pipe opening.

4. A pulse continuous sand filter unit according to claim 1, characterized in that the sand extracting pipe (16) extends vertically downwards to the bottom of the filter tower (1) after extending out of the sand washing tank, the sand blasting jet device (25) is horizontally arranged opposite to the sand outlet (7), the sand extracting pipe (16) is connected with the gas phase pipe (24) and then extends downwards to form a tail end pipe, and the tail end pipe is provided with a stop valve (28).

5. A pulse train sand filter unit according to claim 1, characterised in that the top of the bowl (3) is lower than the top of the clean water tank (17).

6. A pulse train sand filter unit according to any one of claims 1 to 5, wherein the angle-removing cone (6) is a cone with its tip directed upwards and the angle of the cone is equal to the natural repose angle of the sand filter.

7. A pulse train sand filter unit according to claim 6, characterised in that the body (3) is provided with a manhole (29) and a discharge opening (30).

8. A pulse train sand filter unit according to claim 7, wherein the top and bottom stops (13) of the lantern (12) are arranged in a criss-cross pattern.

9. A pulse train sand filter unit according to claim 8, characterized in that a reinforcing support structure is arranged between the bottom of the clean water tank (17) and the outer wall of the drum (3).

10. A pulse continuous sand filter unit according to claim 9, characterised in that the lower head (4) is externally provided with support legs (31) for supporting the filter tower (1).

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