JPS5823128B2 - Lokasouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to fluid filtration devices, and more particularly to fluid filtration devices for removing a portion of a fluid flowing within a passageway through a filter plug concentrically mounted within the passageway. related to cleaning filters.

Conventional cleaning filters have a screen or filter element mounted on a wall along which fluid flows and a portion of the fluid is filtered and removed.

It is also known to use plugs for fluid acceleration in such filter devices.

Such plugs are fluid-impermeable bullet-shaped deflectors placed in close proximity to the screen to increase fluid flow rate and cleaning action.

The working principle of such cleaning filters is that at high flow rates the fluid can undergo the relatively steep rotation required to flow into the wall-mounted screen, but the fluid contained in the fluid Foreign particles are carried directly to the downstream side of the screen due to their greater momentum.

However, such plugs deflect foreign particles toward the filter screen, and the deflected fluid flow thus acts to push the foreign particles into the screen.
Various difficulties arise.

As a result, the cleaning action is reduced along with the action of the filter.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an improved cleaning filter that overcomes the above-mentioned drawbacks of conventional filter devices.

The present invention resides in a wash filter in which a filter plug is mounted within the fluid passageway, whereby fluid flow is accelerated to flow at a high velocity over the wash filter of the plug.

Its general working principle is the same as a conventional cleaning filter.

However, as the plug increases the flow rate, foreign particles tend to be forced towards the outer conduit wall.

Because the filter screen is placed on the plug instead of being mounted on the outer wall as in conventional devices, fewer particles in the area adjacent to the screen are mixed into the fluid being filtered. Therefore, fewer particles will pass through the screen.

In the practice of the present invention, in a preferred embodiment, the filter plug is located in the center of the conduit, and its nose portion is preferably of a smaller diameter than its opposite or base portion.

this? Thus, the main passageway for the initial or unfiltered fluid is generally annular and axially tapered, at least in a region along the axial dimension of the plug, to maintain an accelerated flow over the screen. and facilitate the removal of a portion of that flow through the screen.

The fluid thus removed and filtered is directed through the base of the plug to an outlet line disposed concentrically with the intraconduit passageway.

It is an object of the present invention to provide an improved fluid filtration device in which a portion of the fluid flow is withdrawn through a porous plug disposed within the fluid passageway.

The shape of the plug is such that only a selected, more normal portion of the fluid within the conduit is diverted through the filter screen in the plug, with the remaining fluid flowing continuously downstream of the plug. .

The invention will now be described in detail by way of example embodiments with reference to the accompanying drawings.

FIG. 1 shows a conventional type of fuel filtration device commonly used in the fuel line of a gas turbine engine to remove a portion of the fuel flow to operate the fuel control system for the engine.

The fluid fuel is pumped from its source or tank and passed through a generally cylindrical line or conduit 10.
It also flows through a coarse screen or filter 12 as indicated by arrow 14.

The main portion of the fluid flow in conduit 10 is filtered to some extent by relatively coarse filter 12 before being passed through outlet 16 to the engine.

Also provided in the wall of the conduit 10 is a fine wire mesh screen filter 18, which has a cylindrical shape and acts as a cleaning filter, to more finely filter a portion of the fluid and direct the thus filtered fluid to the outlet 20. This supplies the fuel to the servo mechanism of the fuel control system.

Although such filters are used in fuel control systems, servo systems that require very clean fluid for their operation must be provided with such types of filters.

A cleaning filter partially formed by a screen 18 includes a bullet-shaped plug 2 disposed along the axis of the conduit 10.
2, this plug serves to reduce the cross-sectional area of the flow path and increase the flow rate accordingly.

Although most of the fluid flows through this bullet plug towards outlet 16, at least a portion of the fluid flows through fine wire screen 18 into annular chamber 24 leading to outlet 20 as described above.

This high flow rate is intended to make it difficult for larger foreign particles to move toward the screen 18 and to wash away particles that reach the screen.

Thus, many foreign particles contained in the fluid are removed from the plug 22.
It is expected to flow towards an annular outlet formed between the wall of the conduit 10 and the wall of the conduit 10.

However, it has been observed that the bullet-shaped nose of the plug 22 tends to direct foreign matter toward the conduit walls and screen as fluid enters the area occupied by the plug.

Plug 22 is therefore counterproductive to the intended cleaning action by directing foreign particles toward locations where they will clog the fine screen.

The present invention provides an inverted cleaning filter such that the plug 22 not only provides a reduced flow cross section and associated increased flow rate, but also serves to filter fluid.

In this case, the plug is hollow and has its own fine wire mesh screen or filter through which a delicately filtered flow flows toward the servo mechanism of the fuel control system.

Looking in more detail at the fluid filtration system of the present invention shown in FIG. 2, a fuel line or conduit 10a is adapted to supply fuel under pressure to a gas turbine engine via an outlet 16a.

A coarse filter 12, such as that described in FIG. 1, is preferably provided in this line to remove larger foreign particles that would impair the proper operation of the engine or its fuel injection system.

In accordance with the present invention, a portion of the fluid entering conduit 10a is removed from the fluid within the conduit via a fine filter plug 28 to provide finely filtered fluid to a fuel control system or other servo system. It is directed towards a smaller line 20a provided.

While the conventional wash filter system shown in FIG. 1 uses an annular chamber 24 and associated fine mesh screen 18, the new and improved wash filter shown in FIG. A filter plug 28 is disposed within the conduit, with a straight and impermeable conduit wall forming a straight, impermeable conduit wall.

The plug 28 is disposed concentrically with respect to the passageway 26 and has a blunt dome-shaped fluid-impermeable nose 30 for connecting the downstream end of the plug 28 to the conduit wall and outlet line 20a. The annular base 32 used in
have a smaller diameter.

This nose can be attached to a conduit wall or other structure upstream of the plug, if desired.

What is very important in carrying out the present invention is that the plug 28
is hollow, and its tapered 9AI wall or main body is formed by a thin mesh stainless steel screen 34, which has a truncated conical shape, and its small diameter end connects to the nose 32 or the main body. Its large diameter end is received by an annular base 32.

With such a configuration, the plug has a cylindrical passage as well as an outlet 1.
A tapered annular flow path whose cross-sectional area decreases in the direction of fluid flow is formed for the main part of the fluid that is finally discharged through 6a.

The remainder of the fluid is diverted through the plug's screen 34.

Such a structure provides improved filtration by driving foreign particles contained in the incoming fluid outwardly toward the walls of conduit 10a and away from screen 34.

Also, there is no need for a separate annular chamber or filter screen to be installed within the conduit wall.

The flow rate over the screen 34 is maintained by the tapered shape of the plug 28, and the cleaning action is performed as the fluid is diverted through the screen.

In this improved cleaning filter, the fluid part that has been filtered through the cleaning action has a higher concentration of foreign particles because the foreign particles are driven away from the screen by the nose of the plug. is lower.

In summary, the central location of the filter plug prevents foreign particles from impinging directly onto the screen 34, thus reducing the effectiveness of the cleaning filter due to clogging or damage from high-velocity foreign particles. The tendency is reduced.

These advantages are due to the basic operation of conventional cleaning filters: using high-velocity flow to separate the fluid from foreign particles contained in the fluid and cleaning by fine filter screens placed in the area of such high-velocity flow. It is something that can be gained without losing the benefits of doing so.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a conventional cleaning filter in combination with a conventional coarse filter upstream of a bullet deflector or plug. FIG. 2 is a cross-sectional view of an improved filter according to the present invention. 10... Conduit, 12... Coarse filter, 16... Outlet, 18... Fine filter, 20... Outlet, 22 ......Plug, 24...Annular chamber, 26...Cylindrical passage, 28...Plug, 30...Nose part, 32... ...Annular base, 34...
Fine-grained screen.

Claims (1)

[Claims] 1. A device for filtering and extracting a portion of a fluid from a fluid flow, comprising a fluid inlet receiving the fluid flow and an axially spaced downstream side of the fluid flow from the fluid inlet. a conduit device having a wall defining a passageway having a fluid outlet; a plug mounted within the passageway and having a fluid-impermeable nose proximate the fluid inlet; a plug for providing an annular passageway with a decreasing cross-sectional area in a direction, accelerating the fluid flowing through the annular passageway and deflecting particles contained in the fluid outwardly within the passageway towards the wall; the plug has a hollow screen portion attached to the nose portion at one end, the screen portion being made of a fluid filtering material permeable to fluid, and the plug having a hollow screen portion attached to the nose portion; a fluid-impermeable base having a filtered fluid outlet attached to the other end of the screen portion for receiving fluid diverted through the screen portion.