SU815503A1 - Turbine flowmeter - Google Patents

Description

The invention relates to measuring the flow rate of a liquid, gas or vapor of variable viscosity in various technological processes.

Known turbine flow meters comprising a housing, a turbine, a fairing with a cavity open from the rear end face of the hub, a turbine made in the form of a deflector with a hollow cylinder 10 rum installed inside it, open at the ends, and a signal pickup unit. In such a flowmeter, the measured medium filling the deflector and the hollow cylinder perceives the dynamic pressure of the part of the measured

Closest to the proposed is a turbine flow meter containing a housing, a turbine, a signal pickup unit and a cowl having additional rod-shaped body cowl located in the flow part of the flow meter [2].

However, in the flowmeter, the bearings of the turbine are not unloaded from the axial force arising under the action of dynamic pressure (high-speed pressure) of the measured flow on it. blades, which affects the accuracy of the flow meter.

flow. The resultant laziness acts on the current end face of the hub with a force directed at the same time backward along the turbine from the opposite direction of flow, compensating for the axial force from the measured flow on the bearings of the turbine [1].

The disadvantage of the flow meter is the increased pressure loss due to the significant clogging of the measuring channel by the deflector. The magnitude of these losses may exceed two or more times the losses characteristic of turbine flow meters. thirty

The purpose of the invention is the compensation arising on the bearings of the turbine axial forces.

This goal is achieved by the fact that in a turbine flowmeter containing a housing, a turbine, a signal pickup unit and a cowl having additional flow bodies located in the flow part, a cavity open to one side facing the turbine hub is made in the cowl, and additional flow bodies are made tubular, have additional side openings and communicate with the internal cavity of the fairing with their internal cavity, and the side openings face the impeller.

This goal is achieved by making the lateral holes of the additional tubular fairings in the form of a slot extended along their length, giving the closed section of the tube a groove-like profile.

In FIG. 1 shows the proposed flowmeter, with a hollow inlet cowl, nafig, 2 - section aa in figure 1, in fig. 3 - flowmeter with a hollow outlet fairing; in FIG. 4 a section bB ba of FIG. 3.

Turbine flowmeter contains a housing 1 _T axial impeller 2 _? a signal pickup unit 3, a fairing 4 with a cavity open to the end face of the hub of the turbine 2, additional flow bodies, each of which is a tube with side holes or a groove (degenerate tube). At one end, the inner cavity of the tubular fairings 5 is in communication with the cavity of the fairing 4, and the remaining openings are facing toward the turbine. Due to this, the internal cavity communicates with the zone of reduced pressure (Fig. 1) or with the zone of increased pressure (Fig. 2).

The flow meter operates as follows.

The flow acts on the turbine, and it rotates at a speed proportional to the speed of this flow, or a certain force is created on its blades. In this case, the turbine, and, consequently, the bearings of the latter, is subjected to an axial force proportional to the flow rate pressure (pressure).

When a flow flows onto each additional body of flow around it, a pressure zone is created in front of it and then a zone of reduced pressure is created. This pressure is transmitted through the openings of the additional cowls to the cowling cavity 4. The axial force acting on the turbine bearings in the direction opposite to the flow direction, and the axial force on the bearings from the measured flow is directed in opposite directions and is proportional to the same value - the velocity head. Using the appropriate selection of the parameters of the additional flow bodies and the flow part of the flow meter, the axial force on the bearings can be almost completely compensated. At the same time, various forms of profile flow can be given to additional flow bodies, and they can be installed not only along the chords of the annular plane of the housing passage channel, but also radially on the cowl, which is the hub of the input or output flow guide device, they can simultaneously perform design functions fairing centering elements.

Claims (2)

The invention relates to the measurement of the flow rate of a liquid, gas, or variable viscosity vapor in various technological processes. Turin flowmeters are known, comprising a housing, an impeller, a deflector with a cavity open from the rear end of the hub, an impeller made in the form of a deflector with a hollow cylinder installed inside it, open at the ends, and a sign-removal assembly. In such a flow meter, the measured medium filling the deflector of the hollow cylinder perceives the dynamic pressure of a portion of the measured flow. The pressure arising in this case acts on the rear end of the hub with a force directed opposite to the direction of flow by compensating the axial force from the current measured on the CC turbine bearings. A disadvantage of the flow meter is the loss of pressure loss due to the considerable clogging of the measuring channel by the baffle plate. The magnitude of these losses may Exceed by two or more times the losses typical for turbine flowmeters. Closest to the present invention is a turbine flowmeter, comprising a housing, an impeller, a signal removal unit and a fairing having additional rod-like fairing bodies located in the flow part of the flow meter 2.. However, in the flow meter, the bearings of the impeller are not unloaded from the axial force arising under the action of the dynamic pressure (pressure head) of the flow being measured on its blade, which reflects on the accuracy of the flow meter. The purpose of the invention is to compensate for the axial force generated on the impeller bearings. The goal is achieved by the fact that in a turbine flow meter comprising a housing, an impeller, a signal pickup unit and a fairing having additional wrap bodies located in the flow part, the wound open side of the turbine hub is open in the fairing , have additional side openings and their internal cavity communicates with the internal cavity of the flap, and the side holes face the impeller. The goal is achieved by making the side holes of the additional tubular fairings in the form of a slot along the length of the slot, giving the gully profile to the closed section of the tube. FIG. 1 shows the proposed flow meter with a hollow inlet fairing; FIG. 2 shows a section A-A in FIG. 1 in FIG. 3 - a flowmeter with a hollow outlet fairing; in fig. 4 section bb and FIG. 3. The turbine flowmeter includes a housing 1, an axial impeller 2, a node 3 for picking up a signal, a diverter 4 with a cavity open to the end of the hub of the impeller 2, additional flow bodies 5, each of which is a tube with side holes or a groove {degenerate tube ). one, the condom, the internal cavity of the hard & fairing 5 communicates with the cavity of the fairing-4, and the remaining openings face the impeller. Due to this, the internal cavity communicates with the underpressure zone (Fig. 1) or with the overpressure zone (Fig. 2). The flow meter works as follows. The flow acts on the impeller, and it rotates at a speed proportional to the speed of this flow, or a certain force is created on its blade x. At the same time, the turbine and, consequently, the bearings are subjected to an axial force proportional to the speed pressure (flow pressure. When a flow leaks, each additional flow body in front of it creates an ovoid pressure zone 1, followed by a reduced pressure zone. This pressure is transmitted through the holes of the additional fairings into the cavity of the fairing 4. The axial force acting on the bearings of the turbine in the direction opposite to the direction of flow, and the axial force on the bearings from the measured flow direction They are in opposite directions and proportional to the same and the same value - velocity head. With appropriate selection of the parameters of the additional outflow bodies and the flow part of the flow meter, the axial force on the bearings can be almost completely compensated. At the same time, different forms of the profile can be attached to the additional flow bodies, and they can be installed not only along the chords of the annular plane of the casing's passageway, but also radially on the fairing, which is the hub of the inlet or outlet structure leveling device, they can simultaneously perform the functions of structural elements centering the decoupler. The formula of isooretance 1.Turbine flowmeter, comprising a housing, a turroinka, a signal pickup unit and a fairing, which has additional rod-like running bodies located in the flow part, about T. that, in order to compensate for the axial force, the turbine bearings in the fairing are made the cavity is open on one side, orate to the hub of the impeller, the additional wrap bodies are made of rippled ones, have additional side openings and, with their internal cavity, communicate with the internal cavity of the fairing, and kovymi apertures facing the impeller. 2. A flow meter according to claim 1, characterized in that the side openings of the additional tubular fairings are made in the form of a slot along the length of the slot, fitting a closed section of the tube to a grooved profile. sources of information taken into account in the examination. 1. USSR author's certificate No. 241724, cl. G 01 F 1/12, 1969 2. Attorney certificate of the USSR W bbe21i, cl. 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