CN110613972A - Back-washing pre-filter - Google Patents

Abstract

The invention relates to a backwash pre-filter, which comprises a housing, a water inlet, a water outlet, a reversing valve and a filter screen. The inside of the housing is a filter cavity, and the filter screen is arranged in the housing and the filter cavity Divided into an inner filter cavity and an outer filter cavity, the reversing valve has an inner water channel that can connect the water inlet with the inner filter cavity through rotation, and a flushing pipe is arranged in the filter screen along the axial direction, and the pipe wall of the flushing pipe is distributed with A number of spray holes, the bottom of the flushing pipe is provided with a one-way valve that only allows water to enter the pipe from the outside, and the upper end of the flushing pipe is connected with the inner water channel of the pre-filter reversing valve. In the backwashing condition, the water sprayed from the water spray hole of the flushing pipe has a high flow rate, which greatly improves the backwashing effect on the filter screen, and can flush out the dirt particles stuck in the gap of the filter screen. The passability and life of the filter screen after washing are improved.

Description

A backwash pre-filter

technical field

The invention relates to a pre-filter, in particular to a filter screen cleaning mechanism of the pre-filter.

Background technique

The pre-filter is the first coarse filtration device for household water, which can filter sediment, rust and large particles in tap water. The existing pre-filter includes a filter cartridge and a filter element installed inside the filter cartridge. The upper part of the filter cartridge is provided with a water inlet and a water outlet, and the water inlet communicates with the water outlet through the filter element. When working, the water to be filtered enters the filter cartridge from the water inlet, flows through the filter element to obtain clean water, and the clean water is discharged from the water outlet. After a long period of use, in order to ensure the water quality, the filter cartridge must be disassembled , and then remove the filter to clean, very troublesome.

In order to solve the problems existing in the prior art, people have carried out long-term exploration and proposed various solutions. For example, Chinese invention patent application CN 103372341A discloses a backwash type pre-water filter, including a water inlet and an outlet, a housing, a filter screen and a water flow direction conversion device; The water flowing in from the water port flows through the filter cavity and then flows out from the water outlet; the filter screen is arranged in the housing and separates the filter cavity into an inner filter cavity and an outer filter cavity.

Another example is the Chinese utility model patent CN 206746104 U, which discloses a backwash pre-filter, which switches the water channel through a control valve arranged in the device to realize the backwash function. It is a common practice in this industry to realize the backwashing of the filter screen through water flow reversal. The disadvantage is that the water flow rate of the backwashing is small, and the cleaning effect on the filter screen is limited. It is often necessary to combine the scraper device with scraping and washing to clean the filter screen. . Due to the limitation of the pre-filter structure, the existing scrapers are all arranged on the outside of the filter screen, so only the outer surface of the filter screen can be scraped and cleaned, but the gaps of the filter screen cannot be cleaned.

Contents of the invention

The technical problem to be solved by the present invention is to provide a backwash pre-filter to overcome the above-mentioned shortcomings of the prior art.

In order to solve the above technical problems, the present invention provides a backwash pre-filter, which includes a housing, a water inlet, a water outlet, a reversing valve and a filter screen. The inside of the housing is a filter cavity, and the filter screen is arranged in the housing. And the filter cavity is divided into an inner filter cavity and an outer filter cavity, and the reversing valve has an inner water channel that can connect the water inlet with the inner filter cavity through rotation, and is characterized in that: A flushing pipe is arranged in the direction, and the pipe wall of the flushing pipe is distributed with several water spray holes. The bottom of the flushing pipe is provided with a one-way valve that only allows water to enter the pipe from the outside. The upper end of the flushing pipe is connected to the pre-filter The internal waterway connection of the diverter valve.

The present invention also protects a filter backwashing structure of a pre-filter, which is characterized in that it has a flushing pipe arranged in the filter screen along the axial direction, and several water spray holes are distributed on the pipe wall of the flushing pipe. The bottom of the flushing pipe is provided with a one-way valve that only allows water to enter the pipe from the outside, and the upper end of the flushing pipe is suitable for being connected with the inner water channel of the reversing valve of the pre-filter.

In the backwashing condition, the water sprayed from the water spray hole of the flushing pipe has a higher flow rate (the principle of variable-diameter carrier pressurization), which greatly improves the backwashing effect on the filter screen, and can prevent the water stuck in the filter screen gap. The dirt particles in the filter are flushed out, and the passability and life of the filter screen are improved after backwashing, which is difficult to achieve with traditional low flow rate backwashing. Therefore, the present invention has the advantages of high backwash flow rate, small water consumption and good cleaning effect. In the filtration working condition, the water primary filtered by the filter screen opens the one-way valve and enters the inside of the flushing pipe, thereby ensuring that the filtered water can smoothly flow out from the water outlet of the filter through the reversing valve.

In order to realize straight-through, the reversing valve of the filter of the present invention has a straight-through water channel that can connect the water inlet and the water outlet through rotation.

The reversing valve of the present invention is provided with two water channels, wherein filtering and backwashing can be realized by means of the inner water channel (backwashing can be realized by rotating 180°), and straight-through can be realized by means of the straight-through water channel, which shields the filter and keeps the water supply uninterrupted. When the filter screen of the backwash pre-filter is seriously blocked, or the filter cartridge of the backwash pre-filter leaks, etc., if the professional maintenance personnel cannot rush to the scene for repair in a short time, it will not affect the normal water use of users. Life, at this time, there needs to be a simple way for the user to operate by himself, by adjusting the settings of the backwash pre-filter to let the tap water flow through, and wait for a professional maintenance master to come to do it without affecting the user's normal water life. Repair and maintenance.

In addition, the reversing valve can also be provided with a plug that can block any one of the water inlet and the water outlet through rotation, so that the reversing valve can realize the function of shutting off the water supply.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings.

Fig. 1 is a schematic diagram of the filtration working conditions of the first embodiment of the pre-filter of the present invention.

Fig. 2 is a schematic diagram of the backwashing working condition of the first embodiment of the pre-filter of the present invention.

Fig. 3 is a schematic diagram of the straight-through working condition of the first embodiment of the pre-filter of the present invention.

Fig. 4 is a schematic diagram of the backwashing structure of the filter screen in Embodiment 1 of the pre-filter of the present invention.

Fig. 5 is a schematic diagram of the backwashing structure of the filter screen in the second embodiment of the pre-filter of the present invention.

The symbols in the figure indicate as follows:

1-housing, 3-water inlet, 2-water outlet, 4-filter, 5-filter cavity, 6-reversing valve, 7-straight waterway 7, 8-adjusting knob, 9-outer nozzle, 10 -Inner water nozzle, 11-straight water nozzle A, 12-straight water nozzle B, 13-flushing pipe; 14-water spray hole, 15-one-way valve, 16-inner water channel, 17-filter screen support.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention.

Embodiment one

As shown in Figures 1 to 4, the backwashing pre-filter of this embodiment includes a housing 1, a water inlet 3, a water outlet 2, a filter screen 4 and a flushing pipe 13 arranged inside the strainer, and the flushing pipe 13 The pipe wall is distributed with a number of water spray holes 14, and the filter screen is washed with high-pressure water sprayed from the water spray holes to improve the backwashing effect. The inside of the housing 1 is a filter chamber 5, the filter screen 4 is arranged in the housing 1 and the filter chamber 5 is divided into an inner filter chamber and an outer filter chamber, and a reversing valve 6 is also arranged in the housing 1. An adjustment knob 8 for rotating the reversing valve is arranged above the body 1. By rotating the adjustment knob 8, the switching between backwashing and pre-filter working conditions is realized. Filters generally include two working conditions of filtering and backwashing, and this embodiment also adds a straight-through working condition. The bottom of the housing 1 may be provided with a blowdown valve (not shown in the figure) for blowdown.

The reversing valve 6 has an inner water channel 16 that can communicate with the water inlet 3 and the inner filter cavity by rotation (see Figure 4, the inner water channel is blocked by the shell of the reversing valve in Figures 1 to 3) and the water inlet can be connected by rotation. 3 and the straight-through water channel 7 directly connected to the water outlet 2. The inner water channel has an outer water nozzle 9 suitable for docking with the water inlet 3 and the water outlet 2, and an inner water nozzle 10 at the center of the bottom of the reversing valve 6 . The straight-through water channel 7 has a straight-through water nozzle A11 and a straight-through water nozzle B12 suitable for connecting with the water inlet 3 and the water outlet 2 respectively. Straight through water channel 7 is positioned at the upper half of reversing valve 6, and the ratio of the cross-sectional area of straight through water channel 7 middle part and the water inlet and outlet cross-sectional area is about 50%.

In the backwashing pre-filter of this embodiment, the flushing pipe 13 is arranged coaxially with the filter screen 4, and the flushing pipe is inserted down to a depth of 80% (should not be less than 75%) of the effective height of the filter screen. The pipe wall of the flushing pipe 13 is distributed with some spray holes 14, the aperture range of which is 200 microns-20 microns, and the spray holes can be circular, oval, oval, rectangular or triangular. The bottom of the flushing pipe 13 is provided with a check valve 15 that only allows water to enter the pipe from the outside, and the upper end of the flushing pipe 13 is connected with the inner faucet 10 of the pre-filter reversing valve 6 . The filter screen 4 (specifically, the top of the filter screen bracket 17) is connected or offset with the bottom of the reversing valve 6, so that the water flow cannot or hardly passes between the top of the filter screen 4 and the bottom of the reversing valve 6, and the forced water can only through the strainer.

In order to realize the effect of blocking the water channel, the reversing valve 6 can be provided with a plug (not shown in the figure) that can block any one of the water inlet and the water outlet by rotation.

As shown in Figure 1, it is a schematic diagram of the working condition of the backwash pre-filter. The water flowing in from the water inlet 3 enters the outer filter cavity through the gap between the reversing valve 6 and the housing, and is filtered by the filter screen 5 to reach the inner filter cavity. The inner water channel 16 of the valve 6 flows out from the water outlet 2 to complete the pre-filtering of the incoming water.

In the backwashing condition, it is only necessary to rotate the reversing valve 6 by 180°, so that the outer nozzle 9 is aligned with the water inlet 3 . As shown in Figure 2, the water flowing in from the water inlet 3 flows into the flushing pipe 13 through the inner water channel 16 of the reversing valve 6, and due to the blocking of the one-way valve 15, the water can only be sprayed out from the water spray hole 14. Since the aperture of the water spray hole 14 is relatively small, the water pressure is increased, the flow velocity of the water flow is increased, and the high-velocity flushing of the filter screen 4 is realized. After passing through the filter screen 4, the water reaches the outer filter cavity, and then flows out from the water outlet 2, or opens the drain valve to discharge the sewage, and completes the backwashing of the filter screen.

As shown in Figure 3, it is a schematic diagram of the straight-through working condition of the backwash pre-filter. By rotating the reversing valve 6, the straight-through faucet A11 and the straight-through faucet B12 are respectively connected to the water outlet 2 and the water inlet 3. At this time, the water inlet 3 and the water outlet 2 are directly connected through the straight-through channel 7 of the reversing valve 6. .

As shown in Figure 4, it is the backwashing structure of the filter screen of the pre-filter of the present embodiment, which has a flushing pipe 13 arranged in the filter screen 4 along the axial direction, and the pipe wall of the flushing pipe 13 is distributed with some water spray holes 14 , the bottom of the flushing pipe 13 is provided with a one-way valve 15 that only allows water to enter the pipe from the outside, and the upper end of the flushing pipe 13 is suitable for connecting with the inner water channel 16 (inner faucet 10) of the pre-filter reversing valve 6.

Embodiment two

The difference between the backwashing pre-filter in this embodiment and the first embodiment lies in the backwashing structure of the filter screen. As shown in Figure 5, the flushing pipe 13 is arranged eccentrically, and the water spray hole 14 is arranged on the side of the flushing pipe close to the filter screen. The closer the water spray hole is to the filter screen, the better the flushing effect. See Figure 4 for other symbols in the figure.

In addition to the above-mentioned embodiments, the present invention can also have other implementations. All technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention.

Claims (10)

1. A backwash pre-filter, comprising a housing, a water inlet, a water outlet, a reversing valve and a filter screen, the inside of the housing is a filter cavity, and the filter screen is arranged in the housing and separates the filter cavity Into an inner filter cavity and an outer filter cavity, the reversing valve has an inner water channel that can connect the water inlet with the inner filter cavity through rotation, and the feature is that a flushing pipe is arranged in the filter screen along the axial direction, and the The pipe wall of the flushing pipe is distributed with several spray holes, and the bottom of the flushing pipe is provided with a one-way valve that only allows water to enter the pipe from the outside. The upper end of the flushing pipe is connected to the inner water channel of the pre-filter reversing valve . 2. The backwashing pre-filter according to claim 1, characterized in that: the flushing pipe and the filter screen are concentrically arranged, the water spray holes are arranged on the surface of the flushing pipe, and the depth of the flushing pipe is not lower than the effective filter screen. 3/4 of the height. 3. The backwash pre-filter according to claim 1, characterized in that: the flushing pipe is arranged eccentrically, and the water spray holes are arranged on the side of the flushing pipe close to the filter screen. 4. According to claim 2 or 3, the backwashing pre-filter is characterized in that: the aperture range of the water spray hole of the flushing pipe is: 200 microns-20 microns, and the water spray holes are circular, oblong, Oval, rectangular or triangular. 5. The backwashing pre-filter according to claim 1, characterized in that: the one-way valve is selected from a spherical one-way valve or a cone one-way valve. 6. The backwash pre-filter according to claim 1, characterized in that the inner water channel has an outer water nozzle suitable for docking with the water inlet and water outlet, and an inner water nozzle located at the center of the bottom of the reversing valve , the upper end of the flushing pipe is connected with the inner faucet. 7. The backwashing pre-filter according to claim 1, characterized in that: the top of the filter screen or the top of the filter screen support is connected or offset with the bottom of the reversing valve. 8. A pre-filter according to claim 1, characterized in that: the reversing valve has a straight-through water channel that can connect the water inlet and the water outlet through rotation. 9. The backwash pre-filter according to claim 1, characterized in that: the reversing valve also has a plug that can block any one of the water inlet and the water outlet by rotation. 10. A filter screen backwashing structure of a pre-filter, characterized in that: there is a flushing pipe axially arranged in the filter screen, the pipe wall of the flushing pipe is distributed with some water spray holes, the flushing pipe The bottom of the tank is provided with a one-way valve that only allows water to enter the pipe from the outside, and the upper end of the flushing pipe is suitable for connecting with the inner water channel of the pre-filter reversing valve.