JPH0113533Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a fluid strainer used when filtering a fluid contaminated with impurities.

Configuration of conventional example and its problems As an example of using a fluid strainer, a strainer for a heat exchanger will be described below.

When seawater, river water, etc. is drawn into one passage of a heat exchanger, a strainer as shown in FIGS. 1 and 2 has conventionally been used to prevent impurities from getting mixed in. In the figure, reference numeral 1 denotes a cylindrical strainer body, which has a fluid inlet and a fluid outlet, and the fluid outlet is attached to the inlet of a main body such as a heat exchanger. Reference numeral 2 denotes a cylindrical filtering element built into the strainer body 1, and the portion indicated by the dotted line is a filtering surface through which fluid can freely flow. 3 is a gate valve, and filter element 2
is located inside. Reference numeral 4 denotes one end of the filter element, which is connected to the fluid inlet of the strainer body 1, and the other end 5 is led out from the strainer body and is provided with a stop valve 6.

The flow of fluid during steady operation in the conventional example is shown by each arrow in FIG. First, during steady operation, the gate valve 3 is opened and the stop valve 6 is closed. In this way, the fluid flowing into the filtration element 2 from the fluid inlet is filtered through the filtration surface and sent to a main body such as a heat exchanger. In this case, since the stop valve 6 provided at the other end 5 of the filtration element 2 is closed, the entire filtration surface performs a filtration action and impurities that may damage the main body are left behind.

If impurities continue to adhere to the filtration surface of the filtration element 2 due to the above-mentioned steady operation, it will be necessary to clean it. Conventionally, in such cases, the second
As shown in the figure, the gate valve 3 is closed and the stop valve 6 is opened. In this case, the inlet on the main body side is closed to prevent fluid from entering. In this way, in the filtration element 2 before the gate valve 3, the flow direction is the same as during steady operation, but in the filtration element 2 behind the gate valve 3, the fluid passing through the filtration surface becomes a reverse flow. As a result, impurities adhering to the filtration surface of the filtration element 2 behind the gate valve 3 are separated and discharged to the outside through the opened stop valve 6. However, in the filtration element 2 located before the gate valve 3, the direction of the fluid does not change during steady operation or during reverse flow, and impurities are not removed at all. Sometimes it got blocked. Therefore, if the operating time becomes too long, the filter element must be disassembled and cleaned, or the entire filter element must be replaced.

Purpose of the invention The purpose of the invention is to provide a simple fluid strainer that can clean a wide range of impurities attached to the filtration element without disassembling the strainer, and does not require semi-permanent replacement of parts. .

Structure of the invention The fluid strainer of the invention is built into a cylindrical strainer body having a fluid inlet and a fluid outlet, one end of which is connected to the fluid inlet, and the other end of which is led out from the strainer body. , a cylindrical filtration element having a stop valve, a gate valve that opens and closes a fluid passage inside the cylindrical filtration element, and an area along the inside of the cylindrical filtration element from the fluid inlet to the vicinity of the gate valve. It is equipped with an extended pipe.

With this configuration, the gate valve is opened and the stop valve is closed during steady operation. Therefore,
The filtration element can filter impurities and send clean fluid to a main body such as a heat exchanger. If impurities accumulate on the filter surface, close the gate valve and open the stop valve to allow fluid to pass between the inner end of the pipe and the gate valve, pass through the filter surface, enter the strainer body, and close the gate valve. It enters the interior through the filtration element beyond and is discharged from the stop valve. Therefore, impurities attached to the filter surface are removed.

DESCRIPTION OF EMBODIMENTS FIG. 3 is an explanatory diagram showing the state of the fluid strainer of the present invention during steady operation, and FIG. 4 shows the state during reverse flow. Reference numeral 1 denotes a strainer body, which has a fluid inlet portion and a fluid outlet portion, and the fluid outlet portion is attached to the inlet of a main body such as a heat exchanger. , 2 is the strainer body 1
The cylindrical filtration element is built in, and the part indicated by the dotted line is the filtration surface through which fluid can freely flow. Reference numeral 3 denotes a gate valve, which is provided in the middle part of the filter element 2. One end 4 of the filter element 2 is connected to a fluid inlet of the strainer body 1, and the other end 5 is led out from the strainer body 1 and connected to a stop valve 6. Impurities after filtration are discharged via this stop valve 6.
A pipe 7 extends from the fluid inlet inside the filter element 2 to a position in front of the gate valve 3.

FIG. 3 shows a steady state of operation, in which the gate valve 3 is open and the stop valve 6 is closed. The fluid enters the strainer body 1 from the fluid inlet,
It is ejected from the pipe 7 and flows through the filter element 2 at high speed. In this way, a negative pressure is generated near the tip of the pipe 7, and fluid flows from the outside of the one end 4 of the filtration element 2 into the one end 4 of the filtration element 2 so as to be drawn into the high-speed flow. Due to this flow, impurities adhering to the inner surface of one end 4 of the filter element 2 are peeled off. Since the stop valve 6 is closed, the fluid flows from the inside to the outside in the portion of the filter element 2 near the fluid outlet side, and the filtered fluid is sent from the strainer body 1 to the main body.

FIG. 4 shows the case where the gate valve 3 is closed and the stop valve 6 is open. Therefore, in front of the gate valve 3, the pipe 7 passes through the filtration element 2 from the tip of the pipe 7, enters the strainer body 1, and is sent to the main body, and a part of the water passes from the outside of the filtration element 2 beyond the gate valve 3. A fluid flow is generated inward, and impurities adhering to the filtering surface of the filtering element 2 can be removed. These impurities are discharged from the other end 5 of the filter element 2 to the outside through a stop valve 6. The inlet of the main body is normally left open, but in the event of backflow, a valve or the like may be provided to close the inlet of the main body to prevent fluid from entering.

The filtration surface of the filtration element 2 may be a mesh screen, but as shown in Fig. 5, a metal wire with a triangular cross section is used, with the apex of the triangle facing the outside of the filtration element, and the surfaces of adjacent triangles facing the outside of the filtration element. Abbreviation V
By using a cylindrical filter element 2 that is wound in a radially open state, it is less likely to become clogged, and is more durable and suitable for long-term use. This is because impurities adhering to the gap formed by the sides of adjacent triangles can be easily removed by backflow of fluid or the like.

Further, switching between opening and closing of the valve during steady operation and during backflow can be conveniently performed if the switching is performed in conjunction with each other.

Effects of the invention In this invention, there is a pipe extending from the fluid inlet to the vicinity of the gate valve along the inside of the filtration element built into the strainer body.During steady operation, the gate valve is opened and the stop valve is closed. By doing so, the filtration surface in front of the gate valve 3 is washed by the backflow. Furthermore, when the gate valve is closed and the stop valve is opened, the fluid flows back at the filtration surface on the fluid outlet side of the gate valve, which has the effect of separating impurities from this area from the filtration element. Therefore, when the gate valve is opened and closed, the direction of fluid flow is reversed across the gate valve.
It is now possible to remove impurities from all over the filtration element. Therefore, it has been possible to provide a simple and highly reliable fluid strainer that can be used for a long period of time and requires almost no disassembly because the filtration element is not clogged.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the main part of a conventional strainer during steady operation, Fig. 2 is a cross-sectional view of the main part showing the same during backflow, and Figs. 3 and 4 are the fluid strainer of the present invention during steady operation. FIG. 5 is an enlarged sectional view of a main part showing an example of a filtration element used in a fluid strainer according to the present invention. DESCRIPTION OF SYMBOLS 1... Strainer body, 2... Filter element, 3... Gate valve, 4... One end of the filter element, 5... Other end of the filter element, 6... Stop valve, 7... Pipe.

Claims (1)

[Scope of utility model registration request] A cylindrical filtration element built in a cylindrical strainer body having a fluid inlet and a fluid outlet, one end connected to the fluid inlet, the other end led out from the strainer body, and having a stop valve. A fluid strainer comprising: a gate valve that opens and closes a fluid passage inside the cylindrical filtration element; and a pipe extending along the inside of the cylindrical filtration element from the fluid inlet to the vicinity of the gate valve.