FR2564978A1 - MEASURING DEVICE AND METHOD FOR DETECTING FLUID FLOWS AND FOR MEASURING FLOW SPEEDS - Google Patents

Abstract

THE INVENTION RELATES TO A MEASURING DEVICE AND METHOD FOR DETECTION OF FLUID FLOWS AND FOR MEASURING FLOW SPEEDS. IN THIS DEVICE CONTAINING A RESTRAINT SYSTEM PLACED IN A CRANKCASE 7 AS WELL AS SIGNAL GENERATORS 14, AN INTERIOR SPACE 8 IS PROVIDED IN THE CRANKCASE AND FULLY OR PARTLY CLOSED FOR THE FLUID FLOWING AND OF THE RETAINERS 2 FIXED ON THE RESTRAINT SYSTEM, OUTSIDE OF SPACE 8 AND IN A BALANCED MANNER AROUND THE AXIS 9 OF THE FLOW DIRECTION AND THE RESTRAINT SYSTEM, THE LATTER HAVING AN ELASTIC SUSPENSION 3 AND BEING CONNECTED HAS A UNIT COMPENSATING THE FORCE ACTING ON THE RETAINING ORGANS 2. APPLICATION IN PARTICULAR TO ANEMOMETERS.

Description

The invention relates to a device and a method

  measurement system for detecting flow in

  and / or to measure the flow velocity, based on

of a non-rotating system.

  The flowing fluid may be gaseous or

  quide and be present in any form of state.

  The invention can be used both in

  industry than in agriculture and in addition in weather-

  in the field of hydraulic economics, in short in all areas of research and practice, in which the flow of a fluid must be detected (even if the flow must be eliminated or guaranteed) and everywhere else where the flow velocity of a fluid

in flow must be measured.

  For the determination of the flow rate, many solutions are known. In part of these solutions, the speed sensor is equipped with rotating elements. These rotating elements can be made in the form of structures provided with spoons or wings and

  whose rotational speed is proportional to the

  flow rate of the fluid. In another group of dis-

  positive, a pressure plate is used as a sensor

  perpendicular to the flow and can be deviated to -

  turn of a horizontal axis and which is deflected by the pressure

  dynamic, acting on the surface located in the

  against a weight or other force

  in the initial position.

  The displacement and position of the sensors are transmitted by mechanical means to the reading apparatus or are converted to provide signals

  pneumatic or electric which can be evaluated directly

  or after appropriate treatment.

  In the patent application filed in Hungary

  and published as T / 25356, there is described a

  having a pressure plate which has an or-

  a retainer penetrating the flowing fluid and disposed in a plane perpendicular to the direction of flow and attached to an end of a holding member. The other end of this holding member is mounted on the outer surface of a portion

  deformable strain gauge.

  The device according to British Patent No. 1,434,165 has a similar constitution. In the case of this solution, the retaining member is fixed on an elastic holding member which is mounted in a

  closed lateral derivation of the vehi-

Culminating the flow.

  The device according to Hungarian Patent No. 173,784 is equipped with deflectable wings, which

  are subject to the action of the flow and which are

  suitably adapted so as to be pivotable about parallel or coaxial axes. The deflection of the wings, caused by the flowing fluid, is hampered

  by a suitable structure, but is not prevented.

  The characteristic feature of all these devices lies in the fact that they possess a complex constitution

  and therefore are sensitive to disturbances in particular

  particularly in the case of severe operational constraints

  is lying. Therefore, it is appropriate only in a limited way for the execution of permanent measures

  and reliable - each time under the conditions of

  difficult. The sensor, which has a limited number

  retaining organs and sometimes only one organ

  of restraint, allows only partial measurements to be taken

  tial. Measuring sensitivity is unsatisfactory

  especially in the case of low speeds.

  The purpose of the invention is to eliminate the inconveniences

  the usual constructions and to create a

  It has a simple constitution, superior measurement sensitivity and reliable and undisturbed working in many areas and also

  under severe operating constraints, to de-

  detecting flows and / or measuring the flow velocity by a combination of solutions comprising rotating parts and a pressure plate.

  Consequently, the subject of the invention is a

  for detecting flow of fluids and / or for determining the flow velocity, of the type containing a deflectable retention system under the action of

  flow, one or more signal generators de-

  sensing the force acting on the restraint system and,

  where necessary, a recording unit

  effectively realizing amplification and / or retransmission and / or display and / or processing of the delivered signals

  by the signal generator, characterized in that

  carries a housing, an interior space located inside the housing and closed in whole or in part for the fluid

  in flow, and one or more retaining elements dis-

  placed in equilibrium around the axis of the retaining system, which corresponds to the direction of flow, and fixed on this system being preferably arranged outside

  interior space, and that the restraint system has

  of an elastic seat and / or is connected to a compensating unit

  in whole or in part the force acting on the

retainers.

  It is advantageous that the retaining members

  are tightly connected to the interior space.

  To adjust the sensitivity, you can adjust the

  retainers with respect to the direction of flow.

  The elasticity between the retainers and the

  support of the restraint system can be obtained preferably

  by leaf springs, whose plane passes through the axis of equilibrium. In the case of another preferred embodiment, the compensation unit of the device is a spring and / or a mechanism loaded with a weight and / or a

electromagnetic mechanism.

  Signal generators and / or the communication unit

  thought are preferably placed in the inner space.

  - by being electrically isolated in the event that this

is necessary.

  The invention also relates to a method for

  detect flows in fluids and / or to determine

  to reduce the flow velocity with the aid of the

  0 naked non-rotating according to the invention. This method is characterized in that the torque exerted by the component, acting in the plane perpendicular to the equilibrium axis, is measured by the thrust force of the fluid.

  in flow or deformation - possibly elastic-

caused by this couple.

  The solution according to the invention is based on the fact that a fixed device, which comprises

  a restraint system, but which can be deflected by

  fluid flow and which is carried out under the

  form of a combination of solutions comprising organizations

  rotating systems and solutions with pressure plates, in itself appropriately

  both groups and has further advantages.

  The solution according to the invention increases the measurement sensitivity, which is advantageous especially in the case of low flow rates. In addition, the measuring range is also larger and can extend for example in the ratio 1: 100. The restraint system can be made by any number of retainers of any size. With this device it is possible to measure, in the case of a derediation of the restraint system - disappearing completely in the case of the presence of a compensation unit - that is to say in

  existing restraint systems in practice, the

  exerted by the component, acting perpendicularly to the plane of the equilibrium axis, of the thrust force of the flowing fluid or the deformation - optionally

  clastic - produced by this couple. Compared with

  of the thrust force, acting in another direction, the device behaves in the manner of a rigid device and that is why it does not appear

  virtually no other deformity influencing the

  safe. It follows from the equilibrium position of the restraint system that the pressure of the measurement is independent of the position of the device during the measurement. The difference of the equilibrium axis of the holding system with respect to the direction of flow causes, even at an angle of about 15-20, only a measurement difference of 2- 3%, which is below the precision limits

  measuring devices intended for normal use.

  The device according to the invention can be used in particular in mines to detect the presence of an air flow, to achieve the continuous measurement

  of the flow velocity and to record

  at a point away from the measuring point, for example

during the day.

  Other features and benefits of the

  present invention will emerge from the description given

  hereinafter referenced to the accompanying drawings, on the

  which: - the figure] shows schematically a longitudinal section of the device according to the invention; and - Figure 2 shows the cross section

taken according to plan II-II.

  The retaining system of the device shown in FIGS. 1 and 2 comprises four retaining members 2 which are connected to the support 5 of the retaining system by

  the intermediary of leaf springs guaranteeing a suspension

  3. The leaf springs have on each

  that flat face respectively an extensometric gauge;

  these latter constitute, by being brought together in an appro-

  requested, the signal generators 14 of the device. The sus-

  elastic pension 3, the leaf springs, the support 5 and the signal generator 14 are arranged in

  the inner space 8 of the casings 7 (including a packing

  not shown in FIG.

  port 5 of the restraint system is rigidly connected to the car-

  7. The latter is connected, via

  10 to the envelope 11 of the device, & which the device can be suspended in a mine gallery, and at a corresponding height and in the direction of flow. The device further contains an air guiding member 12, which is disposed on the side of the retaining system, facing the retaining members 2, and an air guiding member 13 for

  take measurements in the opposite direction.

  In the case of the device here chosen for

  for example, the equilibrium axis 9 of the wedge retainer

  with the axis of symmetry of the restraint system and

the entire device.

  A registration unit - not shown-

  used to amplify, retransmit, display and possibly

  the signal, is connected to the sensors-

  signal generators 14 constituted by the gauges exten-

  sométriques. The device operates as indicated below. The flowing air meets the retaining members 2. Under the effect of the shock the direction of the air flow and also the amount of movement of the flowing air vary. The emerging air stream loads the retaining members with a force corresponding to the direction of the flow. A component of this force is perpendicular to the plane of the equilibrium axis 9 and, as a result, the restraint system is loaded by a determined torque. The other components of the force do not involve,

  in the elastic suspension 3, no distortion

the measure.

  The leaf springs are deformed under the action

  torque and this deformation produced at the level of the

  extensometric data a corresponding measurement signal.

  The measurement signal of the sensor-horn generator 14 is sent to an amplifier having a corresponding sensitivity and which amplifies the signal, with the necessary factor. This signal can be viewed on

  any display device - analog or digital

  and / or can be sent to a recording device.

  tration. The amplified signal correspondingly can

  to be broadcast over fairly large distances

  for other signal processing, and can be sent for example to a distribution center

  and / or can be processed by calculations.

  No compensation unit is provided in the device shown in the figures. We will give below more detailed explanations on such a

  unit, also with reference to an exemplary embodiment.

  The compensation unit may be a rotating winding which is connected to the restraint system. Due

  torque acting on the restraint system, wind it up

  turning is obliged to move away while turning. With the help of a corresponding sensor (for example with a sensor

  optics with luminescence diodes, photo-

  transistors, photoresistors, etc.), it is possible to obtain an output signal which is a function of preference

  continuous and monotonous deviation in the angu-

  required. This output signal reaches an amplification

  electronic controller, the output of which is

  requested the characteristic of a current generator. Lors-

  that this output current is sent with a correct phase

'64978

  respondent to the rotating winding, the latter must be

  in the opposite direction to that of the couple acting

  on the restraint system. Thus the deviation of

  rotating bearing is so weak that it can be considered in practice that it is non-existent. In this case

  It is appropriate to use as an output signal the intensi-

  current sent to the rotating winding or the

  voltage proportional to this current intensity.

  The invention has the following main advantages:

  1) Measuring sensitivity and suitability

  the signal are better than in known devices. 2) Due to the equilibrium position of the retaining members, the response threshold is also lower. 3) The device comprises practically only fixed parts, its constitution is simple and thus the costs of manufacture, operation and

maintenance are low.

  4) The device can be used in many

  many domains, operate under operational conditions

  severe and continuous, is reliable and

hardly requires an interview.

  5) With this device, it is also possible to follow variations of very low flow velocities, and for example the necessary or unwanted air flows are identified and adjusted accordingly.

  at the level of workstations, in representative rooms

  conferences, in air conditioned rooms, in cold rooms, in containers and in spaces used for industrial purposes and

in various ways.

  6) The device according to the invention and the measurement method according to the invention are furthermore

  appropriate to measure the conditions under which

  rivers or other large bodies of water and for the determination of the velocity distribution. The solution according to the invention is also suitable for measuring vertical flows.

  very low speed, as for example in

cessation of self-cleaning of water.

Claims (7)

  1. Apparatus for detecting flow of fluids and / or for determining the flow velocity, of the type containing a deflectable retention system under the action of the flow, one or more signal generators detecting the force acting on the restraint system and, where necessary, a unit   recording that amplifies and / or retransmits   mission and / or the display and / or processing of the signals delivered by the signal generator, characterized in that   it comprises a housing (7), an interior space (8)   killed inside the housing (7) and closed in whole or in part for the flowing fluid, and one or more retaining elements (2) arranged in equilibrium around   the axis (9) of the restraint system, which corresponds to the di-   flow, and attached to this system by being   preferably placed outside the interior space   (8), and that the restraint system has an elastic seat   (3) and / or is connected to a compensating unit in whole or in part the force acting on the retaining members (2).   2. Device according to claim 1, characterized   characterized in that the retaining members (2) are connected   sealingly to the interior space (8).   3. Device according to one of the claims   1 or 2, characterized in that the elastic seat (3) is formed by leaf springs located between the retaining members (2) and the support (5) of the retaining system and   that the equilibrium axis (9) is situated in the plane of Spell-blades.   4. Device followed by any of the following   Claims 1 to 3, characterized in that the communication unit   thought is a spring and / or mechanism charged by   a weight and / or an electromagnetic mechanism.   5. Device according to any one of the he   4, characterized in that the sensor-generators   signal units (14) and / or the compensation unit are housed in the interior space (8) - possibly by being electrically insulated.   6. Device according to any one of claims 1 to 5, characterized in that the plane of the retaining members (2) is adjustable relative to the direction of flow. 7. Method for detecting flows in fluids and / or for determining flow velocity   using the device according to any one of the   cations 1 to 6, characterized in that the torque is measured   exercised by the component, acting in the   dicular to the equilibrium axis, the thrust force of the flowing fluid or the deformation - eventually   elastic - caused by this couple.