JPS6240649Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to an automatic backwashing type filter. This invention relates to an automatic backwash filter that employs a flow path switching method using a moving piston mechanism.

B. Prior Art Various types of filters are used for the purpose of removing impurities and sludge mixed in fluids to be filtered such as fuel and lubricating oil. The filter elements of these filters become clogged over time, so as a means to prevent such clogging, the flow path of the fluid to be filtered is switched over time to backwash the filter elements. They are often equipped with a so-called backwash mechanism.

The automatic backwash filter is an indispensable device for maintaining stable continuous operation, for example, when low-quality oil is used as fuel for diesel engines, and various types of filters are used to meet these demands. Automatic backwash filters equipped with a backwash mechanism are commercially available. However, since all conventional automatic backwash filters use a rotary filter element or a rotary switching valve as a component of the backwash mechanism, their overall structure is generally complicated. It has been difficult to maintain the smoothness of the filtration action and backwashing action to a practically satisfactory level. Conventional automatic backwash filters also require a great deal of maintenance effort due to their structural complexity, making it difficult to obtain not only operational reliability but also economical operating conditions. There were inherent inconveniences that could not be overlooked.

B. Purpose of the invention The main purpose of the invention is to provide an automatic backwash filter that can solve the above-mentioned problems found in conventional automatic backwash filters. Another main object of the present invention is to provide an automatic backwashing filter that does not use any rotating filtration member and has a simple structure and excellent stability in filtration and backwashing functions.

C. Structure of the invention The present invention is a filter of the type that automatically switches the flow path of the fluid to be filtered at predetermined time intervals and backwashes two filter elements alternately. An automatic switching valve 11 having a fixed stopper 12 that engages with a swing link 13 of an instantaneous switching mechanism 3
and a guide member 1 that presses the swing link 13.
4, its pressurizing spring 15, and a differential piston mechanism 7, 7', an instantaneous switching mechanism 3 that interlocks with the automatic switching valve 11, and a large diameter piston 35 and a small diameter piston 36 are installed inside along the axial direction. Two backwash valves 17, 1 are installed on both sides of the 3-position control cylinder mechanism 6, which is fitted in a movable manner.
7' and internal chambers 2, 2' of the filter elements 1, 1', and a non-rotating filtration and backwashing mechanism arranged symmetrically.

D. Example Hereinafter, the device of the present invention will be described in detail based on the example shown in FIG. In addition, in the following explanation, the device of the present invention is
All components except automatic switching valve 11, instantaneous switching mechanism 3, and 3-position control cylinder mechanism 6 are 2 pieces 1
Since the parts are arranged symmetrically in pairs, in order to make it easier to understand, the constituent parts located on the left side and the constituent parts common to the left and right sides are indicated by reference numbers without a `` (dart). Components that have the same function as the component and are located on the right side are indicated by reference numbers with a dash (').

First, the filter elements 1 and 1' are filter elements that filter sludge mixed in the fluid to be filtered, such as heavy oil used as fuel for diesel engines, and are selected from commercially available products according to the characteristics of the fluid to be filtered. can be selected as appropriate. An inlet 4 for the fluid to be filtered communicates with the chambers 2, 2' via a flow path (not shown), and an outlet 5 for the fluid to be filtered.
communicates with the automatic switching valve device A via a passage 47. The outlet 5 for the fluid to be filtered also communicates with the interior of the filter element 1, 1' via a flow path (not shown).

Two differential piston mechanisms 7, 7' are arranged symmetrically on the left and right sides of the lower part of the device of the present invention, and inside the differential piston mechanisms 7, 7' there are three liquid chambers 8, 9, 10 and 8',
9' and 10' are formed, respectively. An automatic switching valve 1 is provided between the differential piston mechanisms 7 and 7'.
1 is disposed so as to be freely interlocked with the reciprocating movement of the differential piston mechanisms 7, 7', and a stopper 12 provided at the right end of the automatic switching valve 11 engages with a swingable link 13. It is connected to an instantaneous switching mechanism 3 consisting of a guide member 14 that presses the link 13 and a pressurizing spring 15 of the guide member 14. The left and right ends of the automatic switching valve 11 extend into the third liquid chambers 10 and 10' of the differential piston mechanisms 7 and 7', respectively, and interposed springs 16 and 16' are fixed to the left and right ends, respectively. are doing.

Further, above the differential piston mechanisms 7 and 7', there are two backwash valves 17 and 17', respectively, and a pressure spring 18 that biases the pistons 28 and 28' of the backwash valves 17 and 17'. , 18' are arranged symmetrically. The first liquid chambers 8, 8' formed on the outside of the differential piston mechanisms 7, 7' are connected to the passage 2.
0, 20', check valve 21, 21', throttle valve 22, 2
2', passages 23, 23', automatic switching valve 11, and common passage 24 to a passage 47 leading to outlet 5 of the fluid to be filtered. Further, the second liquid chambers 9, 9' formed in the differential piston mechanisms 7, 7' are
The second liquid chambers 9, 9' have a smaller pressure receiving area than the first liquid chambers 8, 8', and the second liquid chambers 9, 9' have a smaller pressure receiving area than the first liquid chambers 8, 8'.
6', passages 27, 27' and passages 25, 25' to the liquid chambers 29, 29' and liquid chamber 3 formed on the left and right sides of the pistons 28, 28' of the backwash valves 17, 17'.
It communicates with 0,30'. Therefore, the liquid chamber 2
9 and 29' have a larger pressure receiving area than the liquid chambers 30 and 30'. In the drawings, openings designated by the symbol D with a suffix indicate drain outlets, and each of the openings D is connected to an atmospheric pressure release tank (not shown). The backwash valves 17, 17' are
Pressure springs 18, 18' are mounted on the outside to urge the pistons 28, 28' of the backwash valve in the axial direction, and the passages 31, 31' and the passages 32, 32' and is configured to switch and control the flow path of the fluid to be filtered.

The three-position control cylinder 6 is a cylinder mechanism in which a large-diameter piston 35 and a small-diameter piston 36 are fitted so as to be movable along the axial direction. A pressure receiving part 37 that extends inside the piston 35 and can move relative to the piston 35 is provided, and from the other end surface of the small diameter piston 36, backwash/filtration switching lever mechanisms 39, 40, 41, A piston rod 54 for driving the pistons 42 and 43 extends toward the outside of the cylinder. The pressure receiving part 37 has a smaller pressure receiving area than the small diameter piston 36, and
The fitting hole provided in the large-diameter piston 35 is slidable in an oil-tight manner. On the other hand pin 4
The lever 38, which is connected to the piston rod 54 through the lever 38, swings around a fixed pin 39, and a second lever 38 is inserted into a guide groove 44 formed at its swinging end.
A pin 42 of a second lever 41 that swings around a fixed pin 40 is slidably supported. In the embodiment shown in FIG.
is illustrated as a removable pin that connects the first lever 38 and the second lever 41, and by removing the pin 42, the second lever 41 releases the interlocking state with the first lever 38. It can also function as a manually operated switching lever.

The automatic backwash type filter according to the present invention having the above structure switches over time between the filtering action of the fluid to be filtered and the backwashing action of the filter elements 1 and 1' according to the following operating procedure, The filtered fluid is continuously supplied from the outlet 5 to equipment outside the system.

FIG. 1 shows the filter element 1 in filtration operation and the other filter element 1' being backwashed by the fluid to be filtered introduced into the automatic backwash filter. The filter elements 1 and 1' repeat the filtration and backwashing operations at predetermined time intervals by switching the operating position of the switching lever 41 using the automatic switching valve 11 and the 3-position control cylinder 6. However, the filtration time in the filter elements 1 and 1' can be adjusted by adjusting the throttle amount of the throttle valves 22 and 22', and the backwash time can be adjusted by adjusting the throttle amount of the throttle valves 26 and 26'. can be changed respectively. When the second filter element 1' located on the right side in FIG.
is being pressed by the pressure of the pressurized fluid flowing into the second liquid chamber 9' and is rapidly moving to the right.
And the piston 5 of the other differential piston mechanism 7
1 is in a timed operation and is gradually moving to the right.
The fluid to be filtered introduced from the inlet 4 is controlled by the three-position control cylinder 6 to the fixing pin 40 in FIG.
The water flows into the chamber 2 through a switching channel (not shown) connected to the filter element 1, is filtered by the filter element 1, is sent to the outlet 5, and is supplied to external equipment (not shown). In the illustrated state, the automatic switching valve 11 is located toward the left, that is, toward the differential piston mechanism 7, and a portion of the pressurized fluid is
The liquid flows through the common passage 24, the passage 23, and the throttle valve 22 into the first liquid chamber 8, which has a larger pressure receiving area than the second liquid chamber 9, and gradually moves the piston 51 to the right. There is. Due to the movement of the piston 51, the pressurized fluid sealed in the second liquid chamber 9 is discharged to the common passage 24 side through the throttle valve 26 and the passage 27. At this time, the pressurized fluid heading towards the first liquid chamber 8 and the pressurized fluid heading towards the common passage 24 from the second liquid chamber 9 merge in the common passage 24 and have the same pressure, but Due to the difference in pressure receiving area 51, the piston 51 moves to the right even if the first liquid chamber 8 and the second liquid chamber 9 have the same pressure, and the moving speed is adjusted by the throttle valve 22.

When the same pressure is applied to the liquid chamber 29 and the liquid chamber 30 of the backwash valve 17, a force is generated in the left direction due to the pressure receiving area, but the pressure force of the pressurizing spring 18, which is larger than that, causes the piston to 28 is pressed to the right. For this reason, passage 32 has passage 31
The pressurized fluid flows in through the inlet 33 of the three-position control cylinder 6, acts on the left pressure receiving surface of the piston 36, and moves the piston 36 together with the piston 35 to the right end. In this way, the switching lever 41 of the three-position control cylinder 6 is
The second filter element 1' is switched to the backwash position R'. On the other hand, the passage 32' communicates with the opening D'1, and the inlet 4 of the fluid to be filtered and the chamber 2 communicate with the opening D'1.
The communication state is maintained by the position control cylinder 6.

Here, the first of the differential piston mechanism 7'
The liquid chamber 8' includes a passage 20', a check valve 21', a passage 2
3', is in communication with the third liquid chamber 10' of the differential piston mechanism 7' and the opening D'2 via the automatic switching valve 11, and is in communication with the second liquid chamber 9'. A portion of the pressurized fluid flows from the vicinity of the outlet 5 via the passage 24, the passage 27', and the throttle valve 26'. The movement of the pressurized fluid from the first liquid chamber 8' to the third liquid chamber 10' and the inflow of pressurized fluid into the second liquid chamber 9' cause the piston 51' to rapidly move to the right. Moving.

In addition, the liquid chamber 30' of the backwash valve 17' is connected to the throttle valve 2.
6' and the pressure drop in the second liquid chamber 9' due to the movement of the piston 51' of the differential piston mechanism 7', the liquid chamber 29 located on the opposite side with the piston 28' in between The pressure will be lower than '. In this way, the piston 28' of the backwash valve 17' compresses the pressure spring 18' and moves to the right.

When the rightward movement of the piston 51' fitted in the differential piston mechanism 7' is completed, the flow of pressurized fluid passing through the throttle valve 26' ends and the fluid in the backwash valve 17' The pressures in chamber 29' and liquid chamber 30' become equal. The piston 28' of the backwash valve 17' thus begins to move to the left, urged by the pressure spring 18'. The piston 2 of the backwash valve 17'
8' begins to move to the left, pressurized fluid flows into the passage 32', and the pressurized fluid supplied into the three-position control cylinder 6 through the inlet 34 flows into the three-position control cylinder 6. The piston 35 of is pushed to the left. At this time, the pressure of the pressurized fluid is also acting on the left pressure receiving surface of the piston 36, but since the left pressure receiving area of the piston 36 is set wider than the right pressure receiving area, the left end surface of the piston 35 The piston 36 is positioned in the center with the piston 36 in close contact with the vertical wall of the cylinder. Therefore, the switching lever 41 occupies the center position C, and the filter
Elements 1 and 1' are both in filtration action.

Further, the filter element 1 which is in the filtration operation in FIG. 1 starts a backwash operation in accordance with the following procedure. First, the piston 51 of the differential piston mechanism 7 whose moving speed is adjusted by the throttle valve 22 is moved to the first
When the piston 51 gradually moves to the right due to the inflow of pressurized fluid into the liquid chamber 8, the piston 51 compresses the interposed spring 16, and uses the compression force to displace the automatic switching valve 11 to the right. . Due to the rightward displacement of the automatic switching valve 11, the link 13 of the instantaneous switching mechanism 3
When the automatic switching valve 11 swings close to the vertical position, the repulsive force of the interposed spring 16 causes the automatic switching valve 11 to instantaneously move to the abutting portion 48 of the stopper 12 provided on the right side. Therefore, the first liquid chamber 8 of the differential piston mechanism 7 communicates with the opening D2 via the check valve 21, the passage 23, and the third liquid chamber 10 of the differential piston mechanism 7. A portion of the pressurized fluid flows into the second liquid chamber 9 of the differential piston mechanism 7 from the vicinity of the outlet 5 via the throttle valve 26, causing the piston 51 to rapidly move to the left. As the piston 51 moves to the left, the pressures in the liquid chambers 8 and 30 drop more than the pressure in the liquid chamber 29 due to the action of the throttle valve 26 . Thus, the piston 28 moves to the left, the passage 32 communicates with the atmospheric pressure opening D1, and the piston 36 of the three-position control cylinder 6 moves to the left end. The switching lever 41 is therefore switched to the backwashing position R of the first filter element 1, and the filter element 1 enters the backwashing operation according to the same operating procedure as the filter element 1'. In addition, when starting backwashing of filter element 1, automatic switching valve 1
1 is located on the right side, the pressurized fluid supplied from the vicinity of the outlet 5 enters the first liquid chamber 8' of the differential piston mechanism 7' through the common passage 24 and the passage 2.
3' and the throttle valve 22', and accordingly, the piston 51' gradually begins to move leftward from the right end position. That is, the filter elements 1, 1' alternately switch between filtering operation and backwashing operation, and continuously send out the fluid to be filtered to equipment outside the system.

As is clear from the above description, in the device of the present invention, two filters are arranged symmetrically.
Filtration and backwashing operations are automatically repeated for each element at regular time intervals. The filtration time and backwash time depend on the condition of dirt on the filter element.
This can be adjusted by adjusting the flow rate of the pressurized fluid through 2' and 26'.

The filter elements 1 and 1' can be freely selected from general commercially available products according to the characteristics of the fluid to be filtered. It is preferable to use plate filter elements.

E. Effect of the invention The device of the invention has interposed springs 16 and 1 at both ends.
Automatic switching valve 11 and instantaneous switching mechanism 3 equipped with 6'
The pressurized fluid flow path can be automatically switched between filtration operation and backwash operation using It can be realized.

As is clear from the above explanation, the device of the present invention adopts a simple structure filtration/backwash switching mechanism that does not require rotation of the filter element, and is quick and
Reliable switching operation can be achieved. Therefore, the device of the present invention can be expected to greatly exceed conventional devices in terms of reliability of operation and ease of maintenance.

The present invention also solves the unavoidable increase in pressurized fluid consumption in conventional automatic backwash filters that perform continuous backwash operation, as well as the increase in pressurized fluid consumption. In order to avoid increasing the capacity of the pump or piping system, the time interval between backwash operations and the backwash operation time are adjusted using a throttle valve, allowing for short-time backwashing. It is only necessary to increase the flow rate of the pressurized fluid at certain times. Therefore, a good backwashing effect can be achieved with low pressurized fluid consumption.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway front view illustrating the device of the present invention. 1, 1'...filter element, 2, 2'...
...Chamber, 7,7'...Differential piston mechanism,
17, 17'...Backwash valve, 11...Automatic switching valve,
3... Instantaneous switching mechanism, 22, 22', 26, 2
6'...throttle valve, 6...3 position control cylinder.

Claims (1)

[Scope of utility model registration request] It is a type of filter that automatically switches the flow path of the fluid to be filtered at predetermined time intervals to alternately backwash two filter elements, and has a swing link of an instantaneous switching mechanism described later at one end of the valve body. An automatic switching valve consisting of a fixed engaging stopper, a guide member that presses the swing link, its pressurizing spring, and a differential piston mechanism, an instantaneous switching mechanism interlocking with the automatic switching valve, and a large internal A three-position control cylinder mechanism consisting of a large-diameter piston and a small-diameter piston fitted so as to be movable along the axial direction is sandwiched between the three-position control cylinder mechanism. An automatic backwash filter characterized by a symmetrical arrangement of rotary filtration and backwash mechanisms.