SU1302201A2 - Device for measuring drift angle of liquid flow carrying suspension - Google Patents

Abstract

This invention relates to instrumentation technology. To reduce the measurement error, cylindrical fairings 3 and 4 are installed at the ends of receiving elements 1 and 2. Gaps between fairings and cylinders of elements 1, 2 are associated with cylinder diameters by the ratio 4l / d-sO, 09, at which their influence on the coefficient . drag elements. The flow of fluid through the receiving elements 1 and 2 causes the strain gauges 7 to deform, which characterizes the speed and angle of the bevel of the flow. Fairings 3 and 4 prevent the flow from the ends of the cylinders and eliminate the effect of flow on the receiving element 2. The invention is in addition to the author. St. No. 622010. 2 Il. with PNPV and SL f4

Description

The invention relates to instrumentation engineering, can be used to measure the velocity and angle of a bevel of a stream of liquid or gas, and is an improvement of the device according to the author. St. No. 622010.

The purpose of the invention is to reduce the measurement error.

Figure 1 presents the scheme of the device; Fig. 2 is a graph showing the dependence of the drag coefficient of different cylinders on the relative size of the gap (the relative size of the gap is plotted on the abscissa axis, the relative coefficient of cylinder drag coefficient on the vertical axis),

A device for measuring the bevel angle of a suspended fluid flow contains receiving elements 1 and 2 in the form of cylinders arranged successively one after another in a flow with a distance between them equal to one diameter of a cylinder, cylindrical fairings 3 and 4 installed coaxially with receiving elements 1 and 2 The diameter of the cylindrical fairings is equal to the diameter of the receiving elements. Receiving elements are fixed on sensitive elements 5 and 6, made in the form of elastic cantilever beams with pasted strain gages 7, which are covered with a sealant. Sensitive elements and fairings are rigidly fixed in the housing 8 of the device.

A device for measuring the bevel angle of a suspended fluid flow works as follows.

The fluid flow, acting on the receiving elements 1 and 2, causes the strain gauges 7 to deform, which is determined by the flow rate and the bevel angle of the flow. The deformation of the strain gauges of the first sensing element at small bevel angles 0-15 is practically determined only by the speed, since the influence of the second receiving element on the flow past the first is small. The deformation of the strain gauges of the second receiver element is determined by the flow rate and the bevel angle, since the first receiver element strongly influences the flow around the second element (the second element is in the trace of the first).

The measured strain strain gauges can be uniquely determined

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pour both the bevel angle and the speed. The speed is determined by the strain of the strain gauges of the first sensitive element, and the bevel angle is determined by the ratio of the deformation of the second sensitive element to the deformation of the first sensitive element (the ratio is taken to exclude the flow rate). The presence of fairing prevents flow from the ends of the cylinders, which significantly reduces the level of parasitic pulsations acting on the receiving elements. In addition, in the case of a flow around the receiving elements at an angle of pitch cA, the fairings eliminate the influence of the flow on the second receiving element, the part of the end of which is not in the wake of the first receiving element, which increases the accuracy of measurements of both the velocity and the bevel angle.

The technical advantage of the proposed device is to increase the accuracy of measuring the bevel angle of the flow. An estimate of the additional error due to the pitch angle for the known and proposed devices with the same geometrical dimensions (cylinder diameter 5, cylinder length 60 mm) shows that the additional error for the proposed device is three times less than for the known pitch angle of 15 (respectively 3 and 9%).

The size of the gap between the receiving elements and the fairings is chosen from the condition that the drag coefficient of the receiving elements does not depend on the size of the gap (Fig. 2).

Claims (1)

Invention Formula A device for measuring the bevel angle of a suspended fluid flow according to the ed. St. No. 622010, characterized in that, in order to reduce the error, cylindrical fairings are inserted into it, installed on both sides of the ends of the receiving elements, while the diameters of the cylindrical fairings are equal to the diameters of the receiving elements, and the gaps  - between the fairings and cylinders of the receiving elements are connected with the diameter of the cylinders d by the relation Al / d-; 0.09. CX A / Cx, 01 1.0 0.8 0.6 but Oh l 001 0.05 0.1 0.5 1.0 FIG. 2 Editor N. Tupitsa Compiled by Y.Vlasov Tehred I.Popovich Proofreader N.Korol Order 1212/44 Circulation 777 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4  X smooth top hat Hd grungy cylinder . , d -EN d /