FI86111B - Cascade-operated device for regulating and/or measuring flow - Google Patents

Description

1 86111

CASCADE CONTROL DEVICE FOR FLOW CONTROL AND / OR MEASUREMENT

The invention relates to devices for controlling and / or measuring a flow using its own pressure difference by a method based on the cascade principle.

The method is disclosed in patent FI-60069 and is characterized in that a preferably cylindrical space with openings is provided in the flow channel, which - consists of a fixed base and a piston flexibly connected to it, e.g. acting as a main valve plate, - communicates via a first opening on the lower pressure side and through the second orifice to the higher pressure side - the pressure control of the cylindrical space is achieved by changing the orifices themselves and / or externally so that the piston force required to control the flow orifice and the piston force required to adjust the flow at each moment and pressure difference is equal to 25 sum of flow and other forces.

Such devices are the devices shown in Figures 1 of patents FI-60069, SE-8004021-5 and NO-147848, in which a counter-force-generating spring is placed between the valve cover and the combination of the main valve plate and the piston, the valve stem being fixed to the latter by moving it. included and the bearing housing is attached to a fixed base.

Saunas are known from the devices shown in Figures 1 of FI-66078, N0-153316 and EP-0 108 - 371 B1 and Figures 9 of US-4429709 and CA-1172518, in which said spring is placed inside the bearing housing between an adjustable stop on the valve stem and a linear bearing. , 2 86111 the valve stem is attached to the piston acting as the main valve plate by moving it in its cups and the bearing housing is fixed to the fixedly mounted base part.

The devices described above have the following disadvantages: 5 - When the stem is movable together with the piston acting as the main valve plate, their common center of gravity must move inside the outer balls of the linear bearing ball path over the entire adjustment range so that the stem does not rest on two balls. This forces the use of two bearings even where one could handle the load.

- In downstream shut-off valves, the control cone cannot be placed as an extension of the stem if the stem is 15 movable, but outside the bearing housing. This makes the structure more difficult and expensive to manufacture, install and maintain.

At higher pressures, the spring will not fit inside the bearing housing.

20 - For vertical or near-vertical installation, a control pressure difference is required which can also accept the weight of the moving parts. This limits the use of the device at lower pressures if the spring is inside the bearing housing.

25 • «Y. ' The object of the invention is to eliminate the said drawbacks: This is achieved by the features of the invention as set out in the claims.

Although the invention is not bound to any single solution and can be modified in many different ways, it will be explained in detail below with reference to Figure 1 as follows:

Figure 1 shows a cross-sectional view of a cascade-controlled exhaust air valve with constant flow and boost capability and equipped with a built-in timer and a control air filter. The part above the center line CL in the sectional pattern 5 shows a horizontal valve (index a) mounted in a larger diameter duct when the flow takes place from right to left. The lower part of the figure shows vertical valves 10 (index b) mounted in a smaller duct when the flow direction is from bottom to top.

A mounting ring 2 is attached to the end of the duct 1 in the wall, to which the main valve seat 15 3 provided with a seal 5 is attached by means of a nail ring 4a, 4b. The end flange 8 of the channel, which at the same time forms the rear part of the valve, is fixed to the seat 3 preferably by three fixedly mounted supports 6 with notches for locking pieces 9 fixed to the end flange and provided with plastic fillers 7 for flow and sound reasons.

The bottom 10a, 10b of the actuator cylinder is provided with an L-ring 11 attached to it, against which the end flange 8 presses the flange 39, 25 of the control flow filter 12, which at the same time acts as a seal. The parts 8,12 are connected by means of screws 17 to an L-ring 11, which is provided with threaded pieces at them.

The housing 14 of the timer 22, which is provided with a seal 15, 30, is fixed by means of said screws 17 and nuts 19 against the end flange 8 and the centering is ensured by the flange; 13, which acts as a mounting plate for the spindle 23. Said spindle is fixed by a nut 24 which at the same time acts as a center of the shaft 25 of the timer 22. The timer 22 is provided with a flange 26 to which a pin 27 attached is supported by a self-lubricating bearing 16 at the rear of the timer housing 14. Said flange 26 is provided with a claw 28 corresponding to a platform 29 made on the inner surface of the housing 14, limiting the torsional movement of the timer to one revolution.

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The timer 22 is provided with a coil 30 attached thereto by partially bending the coil shell over the rear edge. A tuning wire 31 is placed on the coil. The front of the coil forms a flange 33 in which a hole drilled in 48 opens a connection to the filter 12 when the valve is in the constant flow position. Said flange 33 closes the control flow timer in all positions outside the 0 position and may also be provided with e.g. a plastic sliding surface.

10

The drilling at the center of the end flange 8 and the mandrel 23 together form an annular inlet d1 of the control flow. A ball 32 is placed on the wire 31, which closes the hole when the timer is in the 0 position.

15

The combined piston and main valve plate 20 are attached to the bearing housing 35 by means of an end plate 34, so that they move together. A bore made in the center of the end plate together with a guide cone 36 attached to the spindle 23 forms 20 an annular outlet dg of the guide flow. The linear bearing 37 is fixed to the bearing housing 35 so that the common center of gravity of the moving parts hits the center of the bearing.

The cylinder base 10a, 10b, together with the end flange 8 25, forms a space for the filter 12, which is closed in the middle by a spring housing jacket 38. Said jacket is primarily attached to the base 10a, 10b and the rear end is provided with a flange corresponding to the filter 12 seal to a functioning flange 39, which in turn is an integral part of the filter, • · «. The felt ring 50 filters the air flowing behind the seal 43 through the openings 50 '. Arrangement of the counter spring 40a, 40b. . with its parts 41a, 41b, 42a and the cylinder bottom 10a, 10b, the structure of the valve is the same for both horizontal and vertical valves 35 mounted at an angle between them.

In the horizontal valve, the cylinder base 10a extends over the end of the spring housing 38, forming a support for a counter spring 40a intended to cut off some of the flow forces and corresponding at one end to the guide ring 41a. This in turn rests on the snap ring 42a. Fastening can also take place with threads or as a crimp connection.

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In a vertical installation, the counter spring 40b rests directly at its front end directly on the end plate 34 and at its rear end centered on the guide ring 41b on the end flange 8. The counter force is not spring force, taking into account the weight of the moving parts and the available control pressure or e.g. the difference between the two spring forces 15.

The spring housing jacket 38, the cylinder base 10a, 10b, the end plate 34 and the combined piston and main valve plate 20 form a control pressure space 52. It is sealed 20 by a flexible rolling seal 43 secured at its outer edge, e.g. by gluing and at the inner edge by a resilient ring 44. formation in the rolling seal. The guide 21 attached to the combined piston and the main valve plate 20 moves 25 in the support 6, preventing the rolling seal 43 from buckling, e.g. when cleaning the valve.

"·· Instead of a rolling seal, a bellows may also be used, the spring constant of which is known or a sealing method which generally allows movement 30, which makes the control pressure space hermetically tight in the rest position and sufficiently tight. ·, In motion so that the effect of possible leakage on the control pressure fits within the desired operating accuracy.

\ * ·: 35

Instead of a spring, the force in the direction of the spindle obtained by means of a permanent magnet or solenoid or the compression of a resiliently closed gas volume can also be used instead of a spring! vacuum force.

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The control of the valve can also be implemented in other ways than by means of a tuning wire 31, which can be one-sided or form an endless loop, in which case the timer can be forcibly reset to the 0 position. The control can also be performed manually by providing the pin 27 with a wrench having a desired time scale or by connecting a rod to said pin for further mechanical or manual control.

10 An external control system can be connected to the control device using, for example, mechanical, gravitational or magnetic force and, if necessary, electronic control for control and / or measurement.

15 The basis of the theory of valve operation is presented in general, for example in patent FI-60069, and a thorough mathematical derivation and flow-technical analysis of the control method is presented in reference publication 1.

20 In the constant flow operation, which in the valve of Fig. 1 corresponds to approx. 50% of the volume flow in the economy situation, the room air flows abs. at a pressure P1 through the openings 46 to the annular intermediate space 51, from which further e.g. control pressure P2 and from which it continues to flow through the orifices: 53 and the outlet dg to the channel where the abs.

pressure P3. The control flow is about 0.2 - 0.4% of the main flow. and the pneumatic gain is about 650 times. The shape of the guide cone 30 is dimensioned such that the pressure P2 generated in the guide pressure space 52 by the annular outlet dg. . causes a piston force which, at each moment and the pressure difference, is in equilibrium with the difference between the flow forces and the spring force at the point of movement at which the volume flow remains constant k.o. the pressure difference.

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For example, as the pressure difference P1 - P3 increases, the valve closes until the increase in the flow port dg has reduced the control pressure P2, i.e. increased the force of the vacuum field enough to stop the closing movement at a new point corresponding to the constant flow.

Correspondingly, as the pressure difference P 1 - P 3 decreases, the spring force 5 or the like opens the valve until the reduction of the outlet d 1 n has increased enough control pressure to stop the movement to a new point where the volume flow k.o. the pressure difference is still constant.

10 In constant pressure differential operation, the directions of main flow and spring force or the like are selected so that e.g. the increasing pressure difference opens the valve against the increasing spring force and the control cone is dimensioned so that the flow opening dg increases until the control pressure P2 is sufficiently reduced to stop the difference has returned to the same with the new increased volume flow.

20 25 • · • · · • · «1 · · •» · »a

Claims (5)

8 86111 PATENT CLAIMS: An apparatus for adjusting and / or measuring a fluid medium, wherein the device restricts the flow restrictor by utilizing the fluid's own flow pressure difference, the apparatus comprising a main valve seat 3 with a flow port and a combined piston and main valve plate 20 positioned 10 relative to each other is adjustable by an adjusting device most preferably consisting of a cylindrical space connected by a first opening d1d, to the upper pressure P1 side and by a second opening dg to the lower pressure P3 side, which space is limited to the fixedly mounted cylinder base 10a, 10b, allowing longitudinal movement therein. a piston assembly 38 associated with a combined piston and a main valve plate 20, the center of which is provided with an outlet d2, associated with a sealing member, a spring housing casing 38 and an end flange 8 attached to said cylinder bottom, by means of which a the area ratio of said openings d ^ d / fdg and the Selma space pressure P2 is adjustable by any combination. comprises a linear bearing 37, a bearing housing 35, a spindle 25 23 and a guide cone 36, characterized in that · *. ' that said stem is fixedly mounted on the end flange 8, said bearing housing and the linear bearing are fixedly mounted on the piston and the main valve plate inside said space 52 to move axially on the stem, as a result of which the center of gravity of the moving parts always remains flat. . : at the coil support and the guide cone 36 can be placed as an extension of said spindle and centered in the outlet dg. ‘·· 35 Device according to claim 1, provided with at least one spring 40a for flow y.m. to compensate for the forces, characterized in that the spring is mounted between the guide ring 41a attached to the end of the movable bearing housing 38 9 86111 and the lob of the base, and in that said spring is outside the bearing housing. The device of claim 1, provided with at least one spring 40b for flow y.m. to compensate for the forces, characterized in that the spring is mounted between the fixed end flange 8 and the movable end plate 34 and in that said spring 10 is mounted outside the bearing housing. Device according to claim 2 or 3, characterized in that said spring 40a, 40b is a closed space filled with liquid and / or gas, consisting of at least one flexible part. Device according to claims 2, 3 or 4, characterized in that said spring is a bimetallic spring. 20 10 861 1 1