FI90692B - Installation for measuring and regulating an air flow - Google Patents

Abstract

The invention concerns a measuring and regulating device 10 for air flows, which comprises a central body part R1 and ends for measurement units in connection with this, where a pressure is transmitted from a measurement location in the flow via one measurement unit and the pressure is transmitted from a measurement location which is protected in relation to the flow via the second unit. The size of the air flow can be measured on the basis of the pressure difference between the abovementioned pressures. In the design of the arrangement the installation comprises a regulating device 12 which moves along the body part R1 which can be moved from the end P of the air flow channel K and moved towards the abovementioned end P to regulate the air flow. The installation comprises a screw 14 in connection with the body part R1 with threads 14a which can be engaged for moving the regulating device 12 to regulate the size of the air flow. <IMAGE>

Description

90692

Airflow measurement and control equipment Anläggning för mätning och regiering av en luftström 5

The invention relates to an air flow measuring and control device.

It is known from the prior art to measure the air flow, which takes place as a differential pressure measurement. The so-called the measuring pressure, which is approximately the total pressure, and the reference pressure, which is approximately the static pressure. Measuring pressure means the pressure caused by the air flow directly on the measuring sensor. The reference pressure is the pressure in the duct system, which is not measured from the flow path, but from a sheltered point, out, behind the flange. Based on the pressure difference of the measured pressures, the air volume flow can be read directly. The air flow measuring and regulating device comprises a central body portion and in connection therewith the ends of the measuring connections, the second measuring connection transmitting pressure from the upstream measuring point and the other transmitting pressure from the measuring point in a protected position measurable airflow rate. A method of controlling the air flow is also known from the prior art, in which the desired air flow in the ductwork 20 is adjusted by moving the control member relative to the end of the air flow duct.

The sensitive measuring device reads the pressure difference corresponding to each control position and thus, on the basis of the measurement data, the position of the control element with which the desired air volume flow is realized is adjusted.

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The object of the invention is to improve the above-mentioned measuring method and this has been achieved by a solution in which the control element is moved by means of a screw device which is screwed from the cable outside the duct, to which the measuring connections and a reading device indicating the total pressure and static pressure are also connected. The apparatus 30 is fixed with three wings inside the air duct and the control member is moved relative to the end of the duct to adjust the desired air flow rate based on the differential pressure measurement performed. The apparatus comprises an elongate body piece of aluminum profile 2,90692, by means of which the sleeve part to which the adjusting member is attached is movable. The screw device is screwed into the channel formed in the body part, and the trapezoidal thread of the screw device is rotated by means of a wire from outside the channel system. Flow connections for measuring static pressure and total pressure are connected to the end of a body of metal profile, preferably aluminum profile, from which the total pressure channel is led through a longitudinal bore of the body to a and a flow-protected space between the end piece connected to the body.

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The device according to the invention is mainly characterized in that the device comprises, in connection with the body part, a screw which can be threadedly connected to move the adjusting member for adjusting the amount of air flow.

The invention will now be described with reference to some preferred embodiments of the invention shown in the figures of the accompanying drawings, to which, however, the invention is not intended to be exclusively limited.

Figure 1A shows a measuring and control device according to the invention installed inside a duct 20. On the basis of the figure, the operation of the measuring and control equipment according to the invention will be described.

Figure 1B shows the apparatus according to the invention axonometrically.

Figure 2 is a section I-I of Figure IB.

Figure 3 shows the end frame R2.

Figure 4A shows a cross-section of the end flange 15 of the end body R2.

Figure 4B shows a cross-section of the end piece 17 of the end body R2.

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Figure 4C shows the measuring apparatus side end of the frame R 2 is an axonometric view of a-na.

Figure 5A shows the sleeve part in an axonometric representation.

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Figure 5B shows a vertical section of the sleeve part.

Figure 5C shows a section II-II of Figure 5A.

Figure 6 shows the screw in an axonometric separate view.

Figure 7 shows the wing part in an axonometric separate view.

Figure 8 shows the central body Rj in an axonometric separate view.

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Figure 9 shows an axonometric view of the second end frame R3 of the device according to the invention, which can be connected to an elongate central body part Rj of the device.

Figure 1A shows the apparatus according to the invention installed inside the channel K. As shown in the figure, the measuring and control device 10 is fixed inside the channel K in the vicinity of the end P of the channel K. The fastening takes place by means of wing parts, which wing parts 11 are fastened to the elongate body piece Rj of the apparatus in the grooves Uj, U2, U3 for its wing parts 11.

25 There are three wing parts 11 and they are spaced 120 ° apart. Thus, the attachment achieves a three-point attachment and adequate support from the walls of the channel K.

The adjusting member 12, preferably a perforated plate, is fixed to the sleeve part 13. The sleeve part 13 is moved by turning the screw 14 in one of the directions of rotation shown by the arrows L1, L2. The adjusting member 12 is either moved away from the end P of the channel K or the channel is approximated to the end P depending on the direction of rotation of the screw 14. When the control member 12 is moved in the direction S1, 4 90692, the air flow increases, and when the part is moved in the direction S2, the air flow decreases. With the apparatus 10, precise control of the air flow can be obtained by simultaneously reading the difference between the static pressure and the total pressure from the measuring device M.

Fig. 1B shows the apparatus according to the invention axonometrically with the parts 15 and 17 of the end frame R2 separated from each other. The air flow measuring and regulating device 10 comprises an elongate body part R j, preferably extruded from an aluminum profile, to both ends of which an end structure separate from the duct is connected by a compression fitting; measuring an end-side end of the body R2 and the second end of the terminal body R3.

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The apparatus comprises an adjusting member 12, preferably a perforated plate, which is connected to the sleeve part 13 to be flagged on the body Rj. A screw 14 is operatively connected to the sleeve part 13 by its threads 14a, preferably by its trapezoidal threads.

By rotating the screw 14, the sleeve part 13 operatively connected to the threads 14a of the screw 14 and the adjusting member 12 connected thereto are moved towards and away from the channel end P. The pressure connections Nj, N2 for the total pressure and the static pressure are connected to the end body R3. The pressure is thus transmitted from the end body R2 through the channels fj, f2 in the direction of the body part R1. The static pressure unit fj leads to a protected space D between the end piece 17 of the end flange 15 and 20. The total pressure unit f2 leads to the end surface 15a of the end flange 15 of the end body R2.

The end bodies R2 and R3 are preferably parts made of an artificial material, preferably a plastic material, by injection molding.

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Figure 2 shows a section I-I of Figure IB. For the fastening wings 11, the body Rj has grooves Uj, U2, U3. The total pressure unit is represented by the reference strain f2 and the static pressure unit by the reference strain fj. For the screw 14, there is an elongate cavity 16 in the upper part of the body part Rj; a channel of circular cross-section open 30 from above comprising an opening C. The arrangement allows the trapezoidal thread f s 90692 14a of the screw 14 to contact the inner gripping edges of the sliding sleeve 13 connected to the adjusting member 12; to the abutment parts Ej ^ ... and thus the mobility of the sliding sleeve 13 on the surface of the body part Rj.

3, the frame part R, the measuring side end, is releasably connected to the end frame 5 R2. The end frame R2 comprises two plastic parts; end flange 15 and end piece 17. They can be connected to each other by means of a channel pin 15b connected to the end flange 15. The end flange 15 from its channel spout 15b can be pressed into the recess 17b of the end piece 17.

The end piece 17 is further associated with a channel nozzle 18 comprising a central flow channel 18a. The total pressure is conducted through the flow channel 15c of the end flange 15 to the flow channel 18a of the end piece 17 and further to the body R | to f2.

The static pressure from the space D is applied to the flow channel 19a and to the joint fj of the body Rt 15 of the channel core 19.

The end piece 17 further comprises a recess 20 open at the top with a diameter dimension D (in the form of a circular cross-section into which the end shoulder 14b of the screw part 14 can be inserted. The diameter of the end shoulder 14b corresponds approximately to the diameter of the cavity 20. When the end body R2, its end piece 17, 19 is closed at the same time, a screw 14 is held at one end between the end piece 17 and the body R. The position cavity 16 of the screw 12 in the body Rj is smaller in diameter D2 than the recess 20 and the end 14b in diameter Dj (Dj> D2).

Fig. 4A shows a section of the end flange 15. As shown in the figure, the channel flange 15b of the end flange 15 comprises a central channel 15c which opens from the end face 15a of the end flange 15.

Fig. 4B is a sectional view of the end piece 17 of the end body R2. As shown in Fig. 30, the end piece 17 is connected to duct recesses 18 and 19.

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Fig. 4C shows the end structure in an axonometric view and shows a flexible connecting part 21 between the end piece and the end flange of the end body R2, which acts as a hinge and holds the parts 15, 17 together even when the end flange 15 is turned away from the end piece 17.

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Figure 5A shows the sleeve part 13 in an axonometric representation.

The sleeve part 13 is a plastic part comprising on its surface a groove Q into which the adjusting member 12 can be inserted at its edge. The projections E1, E2, H3 are formed only at the point of the sleeve-10 part 13 inside the sleeve which comes into contact with the thread 14a of the screw part 14. This allows three cuts Cj, C2, C3 to be made in the mouth part of the sleeve. The mouth part of the sleeve is thus resilient when the adjusting plate 12 is placed in the groove Q. Inside the sleeve 13 there are three projections Ej.E ^ E ^ which form between them grooves Gj and G2, the angle of inclination of which with respect to the central axis X of the sleeve corresponds to the pitch of the screw 14 The thread 14a of the setting screw 14 of the adjusting member 12 15 is adapted to engage the sides of the projections Ej.E ^ Ej. When the screw 14 is rotated, for example from the wire connected to the end of the screw 14, the sliding sleeve 13 and the adjusting member 12, preferably the perforated plate, are moved in the desired direction depending on the direction of rotation of the screw 14 (L ^ L ^).

Figure 5B shows a vertical cross-section of the sleeve 13.

Figure 5C shows a cross-section II-II of Figure 5A. It can be seen in the figure that grooves G1, G2 with a pitch angle corresponding to the pitch of the screw 14a of the screw 14 are formed between the projections Ej1 of the screw thread profile.

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Figure 6 shows the screw 14 in an axonometric separate view.

Figure 7 shows the wing part 11 in an axonometric separate view.

Figure 8 shows the central body R, in an axonometric separate view.

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Figure 9 shows the second end frame R3 of the device 10 according to the invention. The end frame R3 is connected to the elongate central body portion Rj. The end body R3 comprises channel nipples F1, F2, F3 and F4. The channel nipples Fj and F2 comprise a central common channel fj "through which static pressure is conducted from space D to the measuring device M and channel nipples F3 5 and F4 comprise a common central channel f2" through which the total pressure is transmitted to the measuring device M. The channel nipples Fj and F3 can be connected to the body , to the static pressure and total pressure channels fj, f2 of the body part. Respectively, flexible connections N can be connected to the channel nipples F2 and F4! and N2, with which the pressure is applied to the measuring device M. In addition, the end body R2 comprises a through hole 30 for the screws 19.

Claims (4)

An air flow measuring and control device (10) comprising a central body part (Rt) and ends for measuring units in conjunction therewith, through which one measurement unit transmits a pressure from a measuring point to the flow and via the other the assembly is transmitted the pressure from a measuring point which is in a protected state in relation to the flow, whereby on the basis of the above pressure difference between the pressures, the amount of air flow and in which the device structure the plant comprises a control means (12) moving along the body part (R) can be measured. ) which can be removed from the end (P) of the air flow duct (K) and transmitted to said end (P) for controlling the air flow, characterized in that the plant comprises a screw (14) in connection with the body part (Rj), whose threads ( 14a) can be coupled to move the control means (12) to control the amount of air flow. Device according to claim 1, characterized in that the screw (14) is arranged in an elongated hollow (16) for the screw of the body (R 1), which hollow is a circular cross section and is open from above comprising an opening (C), wherein the threads (14a) of the screw (14) are in contact via said opening (C) with the sleeve member (13) in connection with the control means (12) to its projections (E 1, 1¾). rotating (Lj,!) of the screw, moving the sleeve (13) in the threads (14a) of the screw (14). Device according to any of the preceding claims, characterized in that the screw (14) comprises trapezoidal threads (14a) and the end of the screw (14) on the measuring side comprises an end stop (14b), the diameter of which is substantially larger than the diameter of the thread ( 14a) of the screw (14), wherein the stop portion of the screw (14) can be connected between the end of the center body (R 1) and the end body (R2) connected to the end of the middle body while the stop end (14b) of the screw (14) is located in the heel (20) with a circular cross-section in the end piece (17) of the end body (R2). Installation according to any of the preceding claims, characterized in that the sleeve part (13) comprises projections (E 1, 1 ...) on the inner surface of the central opening (J) of the sleeve part, between which the thread (14a) of the screw (14) forms a space, the pitch of which corresponds to the pitch of the trapezoid thread (14a), whereby by turning the screw (14) the sleeve (13) and the control member (12) connected thereto are moved in the desired direction. 5