WO2022166997A1 - Automatic backwash filter and working method - Google Patents

Abstract

An automatic backwash filter and a working method, applicable for filtering impurities in sewage. The filter comprises a flow channel switching main valve, a valve plate (8), and a cylinder body (12); the valve plate (8) is disposed on an upper opening of the cylinder body (12); the main valve is disposed on the valve plate (8) and communicated with the inside of the cylinder body (12) by means of flow channels; two flow channels are provided on the valve plate (8), one of the flow channels is a filter flow channel (19) in communication with a space in a filter screen (16), and the other one is a backwash flow channel (18) in communication with a space between the filter screen (16) and the cylinder body (12); the flow channel switching main valve comprises a valve body (1); a sewage outlet (30), a water inlet (31), and a water outlet (32) are sequentially provided on the valve body (1) from left to right; a filter outlet connected to the filter flow channel (19) and a backwash outlet connected to the backwash flow channel (18) are sequentially provided below the valve body (1) from left to right; a two-position five-way reversing valve group that automatically switches to a normal working mode or a backwash mode according to a blockage situation of the filter screen (16) is provided between the sewage outlet (30), the water inlet (31), and the water outlet (32), and the filter outlet and the backwash outlet.

Description

A kind of automatic backwashing filter and working method technical field

The invention relates to an automatic backwashing filter and a working method, and is especially suitable for an automatic backwashing filter used for filtering impurities in sewage in the production of industrial and mining enterprises.

Background technique

Backwash filter is a kind of filter that directly intercepts impurities in water, removes suspended solids and particulate matter in water body, reduces turbidity, purifies water quality, reduces system fouling, algae, rust, etc., to purify water quality and protect other equipment in the system Precision equipment that works properly. The backwash filter can be installed vertically, horizontally or upside down in any direction and in any position. It can be used for water filtration in various industries such as industry, agriculture, municipal power, electronics, medicine, food, printing and dyeing, construction, steel, metallurgy, and paper making.

Due to the development of intelligence (PLC, PAC), the backwash filter is also automated.

The cleaning of the automatic backwash filter can be divided into manual flushing and automatic flushing from the control mode. Most of the previous filters were cleaned manually. When cleaning, the filter net needs to be removed for cleaning, which is a complicated process. In addition, manual cleaning depends on the experience of the cleaner, so the effect is not ideal. In order to meet the accuracy of the automatic backwashing filter and save human resources, the backwashing control filter was born in response to the situation. The specific operation process is: Treatment, control the output device according to certain conditions, and automatically backwash the filter. The automatic backwash filter can be used for the filtration of industrial water, sea water, light chemical industrial waste water and circulating water such as food and pharmaceuticals, as well as the filtration of emulsion regeneration, waste oil, liquid raw materials, etc. In the metallurgical industry, petrochemical industry and power plant water supply and drainage and circulating water systems and media filtration involving liquid, the application of automatic backwash filters is also increasingly widespread. The continuous casting water system, blast furnace water system, The high-pressure water descaling system, emulsion system, closed water circulation system, and liquid media filtration system for hot rolling use a large number of automatic backwash filters. Therefore, designing a device that can automatically clean the filter screen - automatic backwashing filter is of great significance to improve water quality, reduce pollution and save costs.

The current backwashing is set in the filtration stage. The liquid flows in from the lower inlet of the automatic backwashing filter. Some of the liquid will flow directly from the lower end of the filter element, and the other part will enter the top of the filter from the intermediate shunt pipe, and then flow from the upper end of the filter element. inflow. After the liquid penetrates the inner surface of the filter element, it flows out from the upper outlet of the filter, and the particulate impurities are trapped on the inner surface of the filter element.

In the backwash stage, when the filter pressure difference or time reaches the set value, the self-cleaning process starts. The motor reducer drives the cleaning turntable to align a filter element, the backwash valve opens automatically, and the filter element is connected to the sewage pipe. The filter cake on the surface is discharged into the sewage pipeline (in this process, other filter elements are still in the filtering state, so that the entire production line can achieve continuous flow cleaning.

When the backwash of this filter element is completed, the backwash valve is closed, the motor reducer runs, and the cleaning turntable is driven to align the next filter element for backwash operation. When all the filter elements are cleaned one by one, the whole backwashing process ends and the normal filtration stage is entered.

A backwash filter that is widely used in the market now installs a shaft with a sewage suction pipe in the middle of the filter screen, monitors the pressure difference between the inlet and outlet, and starts the drive motor through the controller to drive the suction pipe to rotate through the transmission assembly. At the same time, the sewage outlet is opened, and impurities are discharged from the sewage outlet.

The current backwash filter is basically driven by an external force and driven by a motor during backwashing and filtration work, and cannot be self-cleaning, resulting in a short working time of the filter. The invention provides an automatic backwashing filter, which utilizes the high-speed impact of the waste water to be treated during filtration to drive the spiral blades in the filter cylinder to rotate to achieve the function of self-cleaning, increase the filtration time of the filter, and improve the working efficiency of the filter. Efficiency; at the same time, it does not need to rely on external power, and can achieve the purpose of backwashing by using its own structure to control the flow channel conversion of water flow.

When the filter is working, the water to be filtered enters the cylinder from the water inlet, flows through the filter screen, the filtered water flows out through the water outlet, and the particulate impurities in the water are trapped inside the filter screen. As the filter works for a longer time, more and more impurities are trapped, and the filtration speed becomes slower and slower, while the sewage flows continuously, so the pressure difference between the inlet and the outlet is generated. When the difference reaches the preset value When the filter starts to backwash, the pressure difference drops to the minimum value after the impurities are cleaned, and the device returns to the initial filtering state. The existing automatic backwash filter basically has a slow liquid flow in the cylinder during filtration, and impurities are easily trapped on the inner wall of the filter screen to block the filter holes, resulting in a small filtering area and insufficient sewage treatment capacity.

SUMMARY OF THE INVENTION

Aiming at the shortcomings of the above technologies, an automatic backwashing filter and a working method are provided, which are simple in structure and easy to use. The water pressure is affected by the amount of impurities accumulated on the filter net, and the normal working mode and Backwash mode, no manual operation and no other energy consumption, less dependence on the environment, good backwash effect.

In order to achieve the above technical purpose, the automatic backwash filter of the present invention includes a flow channel switching main valve, a flow distribution plate and a cylinder body, wherein the flow distribution plate is arranged on the upper opening of the cylinder body, and the main valve is arranged on the flow distribution plate and passes through the flow distribution plate. The channel is connected with the inside of the cylinder;

A filter screen with a columnar structure is arranged in the cylinder through the filter screen steel frame, the filter screen is arranged in the filter screen steel frame, and the space in the cylinder is divided into two spaces by the filter screen. To scrape the spiral blade on the inner wall of the filter, the inner space of the filter is located at the bottom of the cylinder with a solenoid valve;

The distribution plate is provided with two flow channels, one is a filter flow channel that communicates with the inner space of the filter screen, and the other is a backwash flow channel that communicates with the space between the filter screen and the cylinder;

The flow channel switching main valve includes a valve body and an end cover arranged on the left side of the valve body. The valve body is provided with a sewage outlet, a water inlet and a water outlet in sequence from left to right, and the bottom of the valve body is sequentially provided from left to right. There is a filter outlet connected with the filter flow channel and a backwash outlet connected with the backwash flow channel; among them, the sewage outlet, the water inlet, the water outlet and the filter outlet and the backwash outlet are automatically switched to work normally according to the blockage of the filter screen. 5/2-way reversing valve group in mode or backwash mode;

The normal working mode is as follows: when the amount of impurities on the filter screen is within the preset normal working range, the sewage outlet is blocked, the solenoid valve is closed, the water inlet is connected to the filter flow channel, and the water inlet impurities are filtered through the filter screen. Then, the filtered water is discharged from the water outlet through the backwash flow channel, and the impurities are left in the filter screen;

The backwashing working mode is: when the impurities on the filter screen exceed the preset normal working range and cause serious blockage, the reversing valve realizes the reversing under the action of the pressure difference, and the water outlet is blocked at this time, and the water inlet and the The backwashing flow channel is connected, and the incoming water washes away the impurities that are blocked and adhered to the inner wall of the filter screen under the action of water pressure, and is discharged from the sewage outlet.

The water inlet of the two-position, five-way reversing valve group is arranged in the middle of the sewage outlet and the water outlet, and the interval distance is equal, and the filter outlet and the backwash outlet are located just below the interval between the sewage outlet, the water inlet and the water outlet, Displace the sewage outlet, water inlet and water outlet from the filter outlet and backwash outlet.

The two-position five-way reversing valve group includes a reversing valve cavity laterally arranged in the middle of the valve body, and a valve stem for switching the sewage outlet, the water inlet and the water outlet is arranged in the reversing valve cavity, and the valve stem is connected to the end. There is a spring b for switching the working mode in the reversing valve cavity between the covers, a cone valve is arranged longitudinally on the left side of the valve body, and a vertical flow channel is connected between the upper part of the cone valve and the backwash outlet, and the cone valve passes through The vertical flow channel is communicated with the right backwash flow channel in the reversing valve cavity, and the lower part of the cone valve is communicated with the filter outlet through the flow channel.

The cone valve includes a vertically arranged cone valve cavity, the bottom of the cone valve cavity is provided with a nut a through a sealing ring, the cone valve cavity is provided with a matching cone valve core and a cone valve seat, the cone valve core and There is a flow channel connected to the reversing valve cavity at the connection of the poppet valve seat, wherein the top of the poppet valve core and the top of the poppet valve cavity are provided with a spring d, and the poppet valve cavity at the position of the spring d is provided with a vertical flow channel Outlet b, the backwash outlet is provided with a vertical flow channel outlet a, the vertical flow channel is respectively connected with the vertical flow channel outlet b and the vertical flow channel outlet a, the poppet valve seat is a through structure and communicates with the flow channel of the filter outlet.

The poppet valve core is provided with a one-way valve structure, and the one-way valve structure includes a damping hole arranged in the poppet valve core with a 90° right turn, and the right turn of the damping hole is set by a nut b and a spring c There is a one-way valve spool, only when the liquid enters from the right side of the damping hole, the one-way valve spool will open, and will not open when the liquid enters from below the damping hole;

When the water pressure of the poppet valve seat from the filter outlet is less than the sum of the pressure of the spring d at the top of the poppet valve core and the water pressure from the vertical flow channel, the flow channel connected to the right side of the reversing valve cavity is blocked. Blocking, when the water pressure from the filter outlet is greater than the sum of the pressure of the spring d at the top of the poppet valve core and the water pressure from the vertical flow channel, the water pressure will lift the poppet valve core to connect the filter outlet to the valve core. The flow passage on the left side of the reversing valve cavity conducts to apply pressure to the valve stem of the reversing valve cavity.

The valve stem is provided with three pistons respectively, and a positioning device to prevent unnecessary shaking of the valve stem is provided between the right side of the valve stem and the spring b, and the positioning device includes a clamp arranged in the reversing valve cavity. The groove also includes the spring a vertically provided inside the valve stem, and the spring a is provided with marbles matching the card slot up and down. In the normal working mode, when the valve stem is located on the right side of the reversing valve cavity, the positioning device is positioned, and the two-position five-way reversing valve group is in the backwashing working mode.

The outer side of the spiral blade is provided with an outer edge of silica gel material, and when the spiral blade rotates under the action of water flow, it is used to wash the impurity particles attached to the inside of the filter screen.

The top end of the filter screen steel frame is matched and connected with the flow distribution plate through the card slot, which is convenient for installation and disassembly at the same time.

A working method for an automatic backwashing filter, which specifically includes: a two-position five-way reversing valve group automatically switches to a normal working mode or a backwashing mode after the water pressure of the cone valve changes according to the blockage of the filter screen;

When there are few impurities on the inner wall of the filter screen, it is the normal working mode: the valve stem in the two-position five-way reversing valve group is located on the left side of the switching valve cavity under the action of the spring b, and the sewage enters the main valve from the middle water inlet In the body cavity, the filter flow channel enters the cylinder through the flow distribution cover, and after being filtered by the filter screen, the impurities are left in the filter screen, and the filtered water flows out from the water outlet; the spiral blade rotates under the pressure of the water outlet in the filter flow channel, driving the spiral The blades scrape the impurities attached to the inner wall of the filter screen, and the rotation of the spiral blades accelerates the flow of water in the steel frame of the filter screen, which helps to improve the filtration efficiency; More and more, the pressure of the water flow channel in the filter screen steel frame increases, the pressure of the flow channel between the filter screen steel frame and the cylinder is low, and after the pressure difference on both sides of the filter screen reaches the preset value determined by the spring d, The water flow enters the poppet valve from the filter outlet side, and the poppet valve spool is pushed up under the action of pressure. At this time, the one-way valve on the poppet valve is closed, the water flow flows into the left side of the switching valve cavity, and the valve stem is in the water pressure. Push down to overcome the spring b and move to the right, and the marbles of the positioning device at the tail of the main valve spool are stuck in the groove to prevent the main valve stem from moving under the irregular action of pressure, thereby ensuring the stability of the filtration process; complete the backwash working mode automatic switching;

In the backwash working mode, the water flow enters the flow channel between the cylinder and the filter screen steel frame from the water inlet through the backwash flow channel; the flow channel pressure in the filter screen frame drops significantly, and the flow between the filter screen frame and the cylinder body The channel pressure increases, and the water flows from the vertical channel outlet a to the vertical channel outlet b into the upper chamber of the poppet valve, the poppet valve is closed under the action of the upper chamber pressure, and the channel pressure between the screen frame and the cylinder continues to increase , increased to discharge the impurities on the filter screen, and the water flow enters the inside of the filter screen steel frame in the reverse direction. During this process, it impacts the impurities attached to the filter screen, and carries the impurities out of the sewage outlet to complete the backwashing work;

When the impurities on the filter screen are cleaned by backwashing, the pressure on the left side of the valve stem decreases, the positioning device of the valve stem is disengaged, and moves to the left under the action of the spring force on the right side. At this time, the left cone valve is closed, and the valve stem is closed. The liquid in the left cavity flows out through the damping hole in the one-way valve on the poppet valve core, the valve stem moves slowly to the left, and finally resets to the far left, and the backwash filter returns to the normal working mode; Working period.

Open the solenoid valve at the bottom of the cylinder regularly to discharge the impurities that are not discharged through backwashing and sink to the bottom.

Beneficial effects:

Through the pressure difference inside and outside the filter screen and its own structural design, the device can switch the flow channel without external power, so as to realize automatic switching between flushing and backflushing; the high-speed water flow of the sewage to be treated is used to impact the screw. The blade can clean the impurities on the inner wall of the filter screen, so as to achieve the effect of energy saving. At the same time, due to the switching between normal work and backwashing, there is no need to consider the operation. It is only determined by the water pressure change caused by the amount of impurities accumulated on the filter screen. The degree of automation is high and can be set work in places that are not easily accessible to workers;

The damping hole and one-way valve are used to realize a certain delay function, and the length of the switching time is controlled by controlling the size of the spring force; the inlet and outlet are concentrated at one end of the filter device, which is convenient for connecting external pipes. A positioning device is installed at the tail of the main valve spool. Through the structure of springs and marbles, the main valve spool is prevented from moving under the irregular action of pressure, thereby ensuring the stability of the filtration process. Realize uninterrupted filtration process, high filtration efficiency, and easy replacement of filter screen.

By installing a spiral blade inside the filter cylinder and the outer side of the blade is made of silica gel material, the blade rotates under the impact of high-speed jet, and the rotation of the blade can wash the impurities attached to the filter screen, which greatly increases the filter filtration time. Improve work efficiency; use the pressure difference on both sides of the filter to switch the flow channel and perform backwashing without using an external power source, saving energy and environmental protection.

Description of drawings

Fig. 1 is the sectional structure schematic diagram of automatic backwashing filter of the present invention in the filtering state;

Fig. 2 is the sectional structure schematic diagram of the automatic backwashing filter of the present invention in the backwashing state;

Fig. 3 is the reversing valve component diagram of the automatic backwashing filter of the present invention;

Figure 4 is a structural diagram of the main valve core of the automatic backwash filter of the present invention;

5 is a structural diagram of the poppet valve core of the automatic backwash filter of the present invention;

6 is a structural diagram of the upper cavity of the poppet valve of the automatic backwash filter of the present invention;

Fig. 7 is the flow channel sectional view of the automatic backwashing filter of the present invention;

FIG. 8 is a structural diagram of the spiral blade of the automatic backwash filter of the present invention.

In the figure: 1- valve body, 2- valve stem, 3- marble, 4- spring a, 5- spring b, 6- end cover, 7- vertical flow channel outlet a, 8- valve plate, 9- gasket, 10-nut, 11-bolt, 12-cylinder, 13-solenoid valve, 14-shaft, 15-spiral blade, 16-filter, 17-filter steel frame, 18-backwash channel, 19-filter flow Road, 20-nut a, 21 sealing ring, 22-cone valve seat, 23-damping hole, 24-cone valve core, 25-nut b, 26-spring c, 27-check valve core, 28- Vertical flow channel outlet b, 29-spring d, 30-sewage outlet, 31-water inlet, 32-water outlet, 33-card slot.

Detailed ways

Embodiments of the present application are further described below in conjunction with the accompanying drawings:

As shown in Figures 1 and 3, the automatic backwashing filter of the present invention includes a flow channel switching main valve, a distribution plate 8 and a cylinder body 12, wherein the distribution plate 8 is arranged on the upper opening of the cylinder body 12, and the main valve is arranged at the upper opening of the cylinder body 12. The valve plate 8 is connected to the inside of the cylinder body 12 through the flow channel; the valve plate 8 and the cylinder body 12 are connected by bolts (11), gaskets (9) and nuts (10);

Wherein the cylindrical body 12 is provided with a filter screen 16 with a columnar structure through the filter screen steel frame 17, the filter screen 16 is arranged in the filter screen steel frame 17, and the inner space of the cylindrical body 12 is divided into two spaces by the filter screen 16, wherein the filter screen The space in the net 16 is provided with a helical blade 15 for scraping the inner wall of the filter screen 16 through the shaft 14. The inner space of the filter screen 16 is located at the bottom of the cylinder 12 with a solenoid valve 13; the top of the filter screen steel frame 17 passes through the card slot. It is matched and connected with the distribution plate 8, and it is easy to install and disassemble;

The distribution plate 8 is provided with two flow channels, one is a filter flow channel 19 that communicates with the inner space of the filter screen 16, and the other is a backwash flow channel 18 that communicates with the space between the filter screen 16 and the cylinder 12;

The flow channel switching main valve includes a valve body 1 and an end cover 6 arranged on the left side of the valve body 1. The valve body 1 is provided with a sewage outlet 30, a water inlet 31 and a water outlet 32 in sequence from left to right. The valve body 1 The bottom is provided with a filter outlet connected with the filter channel 19 and a backwash outlet connected with the backwash channel 18 in turn from left to right; the sewage outlet 30, the water inlet 31, the water outlet 32 and the filter outlet, the backwash outlet There is a two-position five-way reversing valve group that automatically switches between the normal working mode or the backwash mode according to the blockage of the filter screen 16; the water inlet 31 of the two-position five-way reversing valve group is arranged at the sewage outlet 30 and the water outlet 32 In the middle, and the interval distance is equal, the filter outlet and the backwash outlet are located just below the interval between the sewage outlet 30, the water inlet 31 and the water outlet 32, so that the sewage outlet 30, the water inlet 31 and the water outlet 32 are connected to the filter outlet and the reverse. The flushing outlet is dislocated; the two-position five-way reversing valve group includes a reversing valve cavity laterally arranged in the middle position of the valve body 1, and the reversing valve cavity is provided with a sewage outlet 30, a water inlet 31 and a water outlet 32 for switching There is a spring b5 for working mode switching in the reversing valve cavity between the valve stem 2 and the end cover 6, and a poppet valve is provided longitudinally on the left side of the valve body 1. The upper part of the poppet valve is connected to the outlet b There is a vertical flow channel connection between them, the cone valve communicates with the right backwash flow channel 18 in the reversing valve cavity through the vertical flow channel, and the lower part of the cone valve communicates with the filter outlet through the flow channel.

The normal working mode is as follows: when the amount of impurities on the filter screen 16 is within the preset normal working range, the sewage outlet 30 is blocked, the solenoid valve 13 is closed, and the water inlet 31 communicates with the filter channel 19 and passes through the filter. The net 16 filters the impurities in the incoming water, and then the filtered water is discharged from the water outlet 32 through the backwash flow channel 18, and the impurities are left in the filter net 16;

The backwashing working mode is: when the impurities on the filter screen 16 exceed the preset normal working range and cause serious blockage, the reversing valve realizes reversing under the action of the pressure difference, and the water outlet 32 is blocked at this time, The water inlet 31 is communicated with the backwashing channel 18 , and the inlet water washes away the impurities clogging and adhering to the inner wall of the filter screen 16 under the action of water pressure, and is discharged from the sewage outlet 30 .

The poppet valve includes a vertically arranged poppet valve cavity, the bottom of the poppet valve cavity is provided with a nut a20 through a sealing ring 21, and the poppet valve cavity is provided with a poppet valve core 24 and a poppet valve seat 22 that match each other. The connection between the valve core 24 and the poppet valve seat 22 is provided with a flow channel connected to the reversing valve cavity, as shown in Figures 6 and 7, wherein the top of the poppet valve core 24 and the top of the poppet valve cavity are provided with a spring d29 , There is a vertical flow channel outlet b28 at the poppet valve cavity at the position of spring d29, a vertical flow channel outlet a7 is provided on the backwash outlet, and the vertical flow channels are respectively connected to the vertical flow channel outlet b28 and the vertical flow channel outlet a7. The seat 22 is a through structure and communicates with the flow passage of the filter outlet; as shown in FIG. 5 , the poppet valve core 24 is provided with a one-way valve structure. °Right steering damping hole 23, the right steering position of the damping hole 23 is provided with a one-way valve spool 27 through a nut b25 and a spring c26. Only when the liquid enters from the right side of the damping hole 23, the one-way valve spool 27 will Open, when the liquid enters from below the damping hole, it will not open; when the water pressure of the poppet valve seat 22 from the filter outlet is less than the pressure of the spring d29 at the top of the poppet valve core 24 and the water pressure from the vertical flow channel When and, the flow channel communicating with the right side of the reversing valve cavity is blocked. When the water pressure from the filter outlet is greater than the pressure of the spring d29 at the top of the poppet valve core 24 and the water pressure from the vertical flow channel When and, the water pressure will push up the poppet valve core 24 to connect the filter outlet with the flow channel on the left side of the reversing valve cavity to apply pressure to the valve stem 2 of the reversing valve cavity.

The valve stem 2 is provided with three pistons respectively, and a positioning device to prevent unnecessary shaking of the valve stem 2 is provided between the right side of the valve stem 2 and the spring b5, as shown in Figure 4 and Figure 7, the The positioning device includes a slot 33 arranged in the reversing valve cavity, and also includes a spring a4 vertically provided inside the valve stem 2, and the spring a4 is provided with marbles 3 that match the slot 33. When the reversing valve cavity is on the left side, the 5/2-way reversing valve group is in the normal working mode. When the valve stem 2 is located on the right side of the reversing valve cavity, the positioning device is positioned, and the 5/2-way reversing valve group is in reverse. Flush working mode.

As shown in FIG. 8 , the outer side of the spiral blade 15 is provided with an outer edge of a silica gel material. When the spiral blade 15 rotates under the action of the water flow, it is used to wash the impurity particles attached to the inside of the filter screen 16 .

A working method of using the automatic backwashing filter, which specifically includes: the two-position five-way reversing valve group automatically switches the normal working mode or the backwashing mode after the water pressure of the poppet valve changes according to the blockage of the filter screen 16;

When there are few impurities on the inner wall of the filter screen 16, it is the normal working mode: the valve stem 2 in the two-position, five-way reversing valve group is located on the left side of the switching valve cavity under the action of the spring b5, and the sewage flows from the middle water inlet 31 Enter the main valve body cavity, enter the cylinder body 12 through the filter flow channel 19 on the distribution cover 8, and leave the impurities in the filter screen 16 after being filtered by the filter screen 16, and the filtered water flows out from the water outlet 32; The outlet water in the flow channel 19 rotates under pressure, and drives the spiral blades 15 to scrape the impurities attached to the inner wall of the filter screen 16. At the same time, the rotation of the spiral blades 15 accelerates the flow of the water flow in the filter screen steel frame 17 and assists in improving the filtration efficiency. When more and more impurities cannot be scraped off by the spiral blades 15 on the inner wall of the filter screen 16, the pressure of the water flow channel in the filter screen steel frame 17 increases, and the flow between the filter screen steel frame 17 and the cylinder 12 increases. The pressure of the channel is low, and after the pressure difference between the two sides of the filter screen 16 reaches the preset value determined by the spring d29, the water flow enters the poppet valve from the filter outlet side, and the poppet valve spool 24 is pushed up under the action of the pressure. At this time, the poppet valve The one-way valve above is in the closed state, the water flows into the left side of the switching valve cavity, the valve stem 2 overcomes the spring b5 to move to the right under the push of water pressure, and the marble 3 of the positioning device at the tail of the main valve spool is stuck in the slot 33 to prevent The main valve stem 2 moves under the irregular action of pressure, so as to ensure the stability of the filtration process; complete the automatic switching of the backwash working mode;

As shown in FIG. 2 , in the backwash working mode, the water flows from the water inlet 31 through the backwash flow channel 18 into the flow channel between the cylinder 12 and the filter screen steel frame 17 ; the flow channel pressure in the filter screen frame 17 drops significantly , the flow channel pressure between the screen frame 17 and the cylinder 12 increases, and the water flows from the vertical flow channel outlet a7 to the vertical flow channel outlet b28 into the upper cavity of the poppet valve, the poppet valve is closed under the action of the upper cavity pressure, and the filter screen The pressure of the flow channel between the frame 17 and the cylinder 12 continues to increase until the impurities on the filter screen 16 are discharged, and the water flow enters the inside of the filter screen steel frame 17 in the reverse direction. During this process, the impact is attached to the filter screen 16. and carry the impurities out of the sewage outlet 30 to complete the backwashing work;

When the impurities on the filter screen 16 are cleaned by backwashing, the pressure on the left side of the valve stem 2 is reduced, the positioning device of the valve stem 2 is disengaged, and moves to the left under the force of the right spring 5. At this time, the left cone The valve is closed, the liquid in the cavity on the left side of the valve stem 2 flows out through the damping hole 23 in the one-way valve on the poppet valve spool 24, the valve stem 2 slowly moves to the left, and finally resets to the far left, and the backwash filter returns to normal working mode ; Complete a working cycle of automatic filtration and backwashing.

The solenoid valve 13 provided at the bottom of the cylinder body 12 is periodically opened to discharge the impurities that are not discharged through backwashing and sink to the bottom.

Claims (10)

An automatic backwashing filter is characterized in that: it comprises a main valve for channel switching, a distribution plate (8) and a cylinder (12), wherein the distribution plate (8) is arranged on the upper opening of the cylinder (12), The main valve is arranged on the distribution plate (8) and communicates with the inside of the cylinder (12) through the flow channel; Wherein the cylinder body (12) is provided with a filter mesh (16) with a columnar structure through the filter mesh steel frame (17), the filter mesh (16) is arranged in the filter mesh steel frame (17), and the cylinder is removed by the filter mesh (16). The space in the body (12) is divided into two spaces, wherein the space in the filter screen (16) is provided with a spiral blade (15) for scraping the inner wall of the filter screen (16) through the shaft (14), and the filter screen (16) The inner space is provided with a solenoid valve (13) at the bottom of the cylinder (12); The distribution plate (8) is provided with two flow channels, one is a filter flow channel (19) that communicates with the inner space of the filter screen (16), and the other is between the filter screen (16) and the cylinder (12). a backwashing flow channel (18) connected in space; The flow channel switching main valve includes a valve body (1) and an end cover (6) arranged on the left side of the valve body (1), and the valve body (1) is sequentially provided with a sewage outlet (30), an inlet port (30) from left to right on the valve body (1). The water port (31) and the water outlet (32), the lower part of the valve body (1) are sequentially provided with a filter outlet connected with the filter channel (19) and a backwash outlet connected with the backwash channel (18) from left to right ; Among them, between the sewage outlet (30), the water inlet (31), the water outlet (32), the filter outlet and the backwash outlet, there are two digits that automatically switch between the normal working mode or the backwash mode according to the blockage of the filter screen (16). Five-way reversing valve group; The normal working mode is as follows: when the amount of impurities on the filter screen (16) is within the preset normal working range, the sewage outlet (30) is blocked, the solenoid valve (13) is closed, and the water inlet (31) is connected with the water inlet (31). The filter flow channel (19) is connected to filter the impurities in the water through the filter screen (16), and then the filtered water is discharged from the water outlet (32) through the backwash flow channel (18), and the impurities are left in the filter screen (16) Inside; The backwashing working mode is as follows: when the impurities on the filter screen (16) exceed the preset normal working range and cause serious blockage, the reversing valve realizes reversing under the action of the pressure difference, and the water outlet (32) is blocked at this time. When blocked, the water inlet (31) is communicated with the backwash flow channel (18), and the inlet water will wash away the impurities that are blocked and adhered to the inner wall of the filter screen (16) under the action of water pressure, and will be discharged from the sewage outlet (30) . The automatic backwashing filter according to claim 1, characterized in that: the water inlet (31) of the two-position, five-way reversing valve group is arranged in the middle of the sewage outlet (30) and the water outlet (32), and is spaced apart from each other. The distance is the same, the filter outlet and the backwash outlet are located just below the interval between the sewage outlet (30), the water inlet (31) and the water outlet (32), so that the sewage outlet (30), the water inlet (31) and the water outlet (32) It is dislocated from the filter outlet and the backwash outlet. The automatic backwashing filter according to claim 1, characterized in that: the two-position five-way reversing valve group comprises a reversing valve cavity laterally arranged in the middle position of the valve body (1), and the reversing valve cavity The valve rod (2) for switching the sewage outlet (30), the water inlet (31) and the water outlet (32) is provided in the body, and a valve rod (2) is provided in the reversing valve cavity between the valve rod (2) and the end cover (6). The spring b (5) for switching the working mode, the left side of the valve body (1) is provided with a cone valve in the longitudinal direction, the upper part of the cone valve and the backwash outlet are connected with a vertical flow channel, and the cone valve is connected with the vertical flow channel through the vertical flow channel. The right backwashing flow channel (18) in the reversing valve cavity is communicated, and the lower part of the cone valve is communicated with the filter outlet through the flow channel. The automatic backwashing filter according to claim 3, characterized in that: the cone valve comprises a vertical cone valve cavity, the bottom of the cone valve cavity is provided with a nut a (20) through a sealing ring (21), and the cone The valve cavity is provided with a matching poppet valve core (24) and a poppet valve seat (22), and a connection between the poppet valve core (24) and the poppet valve seat (22) is provided with a connection with the reversing valve cavity The flow channel, wherein the top of the poppet valve core (24) and the top of the poppet valve cavity are provided with a spring d (29), and the poppet valve cavity at the position of the spring d (29) is provided with a vertical flow channel outlet b (28), The backwash outlet is provided with a vertical flow channel outlet a (7), the vertical flow channel is respectively connected with the vertical flow channel outlet b (28) and the vertical flow channel outlet a (7), the poppet valve seat (22) is a through structure and is connected with the vertical flow channel outlet b (28) respectively. The flow channel of the filter outlet communicates. The automatic backwashing filter according to claim 4, characterized in that: the poppet valve core (24) is provided with a one-way valve structure, and the one-way valve structure comprises a check valve structure arranged in the poppet valve core (24). ) inside the 90° right-turned orifice (23), the right-turn of the damping hole (23) is provided with a one-way valve spool (27) through the nut b (25) and the spring c (26), only when the liquid flows from the damping The check valve spool (27) will only open when the right side of the hole (23) enters, and will not open when the liquid enters from below the damping hole; When the water pressure from the filter outlet of the poppet valve seat (22) is less than the sum of the pressure of the spring d (29) at the top of the poppet valve core (24) and the water pressure from the vertical flow channel, it will be related to the reversing valve. The flow channel connected to the right side of the cavity is blocked. When the water pressure from the filter outlet is greater than the sum of the pressure of the spring d (29) at the top of the poppet valve core (24) and the water pressure from the vertical flow channel, Then, the water pressure pushes up the poppet valve core (24) to connect the filter outlet and the flow channel on the left side of the reversing valve cavity to apply pressure to the valve stem (2) of the reversing valve cavity. The automatic backwashing filter according to claim 3, characterized in that: the valve stem (2) is respectively provided with three pistons, and between the right side of the valve stem (2) and the spring b (5) is provided A positioning device for preventing unnecessary shaking of the valve stem (2), the positioning device includes a slot (33) arranged in the reversing valve cavity, and also includes a spring a (4) vertically arranged inside the valve stem (2). ), and the spring a (4) is provided with marbles (3) matching the slot (33). In the normal working mode, when the valve stem (2) is located on the right side of the reversing valve cavity, the positioning device is positioned, and the two-position five-way reversing valve group is in the backwashing working mode. The automatic backwashing filter according to claim 1, characterized in that: the outer side of the spiral blade (15) is provided with an outer edge of a silica gel material, and when the spiral blade (15) rotates under the action of water flow, it is used to wash the filter screen (16) Impurity particles attached inside. The automatic backwashing filter according to claim 1, characterized in that: the top end of the filter screen steel frame (17) is matched and connected with the distribution plate (8) through the clamping groove, which is convenient for installation and disassembly. A working method using the automatic backwashing filter described in any of the preceding claims, characterized in that: the two-position five-way reversing valve group automatically switches to normal after the water pressure of the cone valve changes according to the blockage of the filter screen (16). Working mode or backwash mode; When there are few impurities on the inner wall of the filter screen (16), it is the normal working mode: the valve stem (2) in the 5/2-way reversing valve group is located on the left side of the switching valve cavity under the action of the spring b (5). , the sewage enters the main valve body cavity from the intermediate water inlet (31), enters the cylinder body (12) through the filter flow channel (19) on the distribution cover (8), and filters the impurities through the filter screen (16). In the net (16), the filtered water flows out from the water outlet (32); the spiral blade (15) rotates under the water pressure of the water outlet in the filter channel (19), which drives the spiral blade (15) to adhere to the inner wall of the filter screen (16). At the same time, the rotation of the spiral blade (15) accelerates the flow of the water flow in the steel frame (17) of the filter screen, which helps to improve the filtration efficiency; when the inner wall of the filter screen (16) cannot be scraped by the spiral blade (15) More and more impurities are wiped off, the pressure of the water flow channel in the filter screen steel frame (17) increases, the pressure of the flow channel between the filter screen steel frame (17) and the cylinder (12) is low, and the filter screen (16) After the pressure difference between the two sides reaches the preset value determined by the spring d (29), the water flow enters the poppet valve from the filter outlet side, and the poppet valve spool (24) is pushed up under the action of the pressure. At this time, the poppet valve The one-way valve above is closed, the water flows into the left side of the switching valve cavity, the valve stem (2) overcomes the spring b (5) and moves to the right under the push of water pressure, and the main valve spool tail positioning device marble (3) The slot (33) is stuck to prevent the main valve stem (2) from moving under the irregular action of the pressure, thereby ensuring the stability of the filtering process; the automatic switching of the backwashing working mode is completed; In the backwash working mode, the water flows from the water inlet (31) through the backwash flow channel (18) into the flow channel between the cylinder (12) and the filter screen steel frame (17); the flow in the filter screen frame (17) The channel pressure drops significantly, the channel pressure between the screen frame (17) and the cylinder (12) increases, and the water flows from the vertical channel outlet a (7) to the vertical channel outlet b (28) into the upper cavity of the cone valve , the poppet valve is closed under the action of the upper chamber pressure, and the flow channel pressure between the filter screen frame (17) and the cylinder body (12) continues to increase, increasing to the extent that the impurities on the filter screen (16) are discharged, and the water flow reverses. To enter the inside of the filter screen steel frame (17), in the process, the impurities attached to the filter screen (16) are impacted, and the impurities are discharged from the sewage outlet (30) to complete the backwashing work; When the impurities on the filter screen (16) are cleaned by backwashing, the pressure on the left side of the valve stem (2) is reduced, the positioning device of the valve stem (2) is disengaged, and under the force of the right spring (5) Move to the left, at this time the left poppet valve is closed, the liquid in the left cavity of the valve stem (2) flows out through the damping hole (23) in the one-way valve on the poppet valve spool (24), and the valve stem (2) slowly left Move, and finally reset the leftmost side, the backwash filter returns to normal working mode; complete a working cycle of automatic filtration and backwashing. The working method according to claim 9, characterized in that: the solenoid valve (13) provided at the bottom of the cylinder (12) is periodically opened to discharge impurities that are not discharged through backwashing and sink to the bottom.

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