SU1004860A1 - Pickup of metal inclusuins in liquid flow - Google Patents

Description

(54) METAL INCLUSION SENSOR IN THE FLOW

one

The invention relates to a measurement technique, in particular, to devices for diagnosing pumps that pump cryogenic liquids, where continuous monitoring of bearing performance is a necessary condition for preventing accidents.

A known sensor for detecting metal particles in a fluid flow, comprising a housing, and a winding mounted coaxially with it on a cylindrical frame and a slot filter 1

The disadvantage of this device is Vlad (bts is low sensitivity to metal particles with a size less than 1 mm O mm, since the level of the output signal depends on the degree of particle trajectory distance from the inner surface of the inductance coil frame.

At the same time, particles than the cell size of the filter pass inside it and are not registered by the device.

They carry basic information about the early stages of bearing wear.

In the case of using a known device for detecting particles in a stream of cryogenic liquid, such as hydrogen, nitrogen, oxygen, and due to the occurrence of filter cavities, resulting in a two-phase flow and vibration of the inductance coil, significant distortions of the useful signal occur.

In addition, this device is characterized by a decrease in sensitivity oikey due to the placement of the filter in the magnetic field of the inductor.

The purpose of the invention is to increase the sensitivity.

Claims (1)

The goal is achieved by inserting a sleeve with screw blades coaxially with KOJ into the gauge of metallic inclusions in the KikoTit flow, which includes a housing and an impeller mounted on the cylindrical frame installed with it, the output end of the sleeve is finished in the shape of a fairing, the end of which gives with the beginning of the winding, with the angle of elevation of the screw blades of the sleeve lying within 43 ° p 52 and the height of the blades is determined by the ratio of the ratio e-t) -a-s, where 6 is the height of the blades; D is the inner diameter of the housing; 6 - diameter of the sleeve; WITH -; the distance between the surface of the fairing and the internal dimension of the frame. The drawing shows the proposed sensor. The sensor of metal inclusions in the fluid flow contains the body 1 mouth. Newly aligned with pipeline 2 through which a controlled flow passes, a cylindrical frame 3, a sleeve 4 with screw blades 5 and a fairing 6 whose pointed end coincides with the beginning of the & trays 7, while the fairing 6 forms with the cylindrical frame 3 an annular channel 8. Devices works as follows. Controlled fluid flow, the passage from the pipeline 2 into the ± 5 cavity of the body meets in its way the sleeve 4 with screw blades 5, which form helical channels with the inner surface of the body 1, the total area of the flow area of which is defined as where channels; {„Is the area of one channel; Q is the mass flow rate of the fluid passing through the device; O is the density of the liquid; - the rotational component of the flow velocity, which is extracted from the condition. where p is the pressure of the controlled flow in the pipeline; cryogenic fluid temperature; ate the flow rate right through the sensor; KI.K are constant coefficients characteristic of each type of cryogenic liquid. The specified value of the rotational velocity velocity components ensures, on the one hand, a reliable approximation of metal particles contained in the flow to the inner surface of the inductance framework under the action of centrifugal forces resulting from the rotation of the flow, and on the other hand the absence of cavitation of cryogenic liquid during its passage through device. Having obtained the rotational component dKopocTH of the specified value, the flow enters through the annular channel 8 into the zone of the winding 7, where changes in the amplitude of electromagnetic oscillations produced by winding 7 are recorded, depending on the concentration and size of megalogic inclusions in the fluid flow. As shown by the spills on a row of cryogenic liquids, making an angle, lifting screw blades 5 less than 43 leads to an increase in the length of the channels, and, accordingly, the overall dimensions of the device, as well as an increase in flow resistance and a decrease in the sensitivity of the sensor. When the lifting angle of the screw blades 5 is more than 52, local zones of turbulent slit currents are formed on the shadow side of the blades, in which separate foci of cryogenic fluid arise, which is unacceptable according to the operating conditions and also reduces the sensitivity of the sensor. The annular channel 8 eliminates the possibility of the formation of a gas bubble and stall currents at the outlet of the sleeve 4. Thus, the sensitivity of the device increases, since all the metal particles, regardless of their size, pass near the turns of the catcher. Performing the device in accordance with the dependences 1 and the dependences completely excludes the possibility of the occurrence of cavitation or stall flows of the cryogenic liquid and does not introduce significant hydrodynamic resistance to the flow. In addition, the proposed arrangement eliminates randomness of the particle trajectories and the effect on the magnitude of the signal from the inner wall of the coil coil to the particle trajectory, since all the particles pass along the inner wall of the coil frame. Consequently, in the proposed device, the magnitude of the signal depends only on the size of the particles. This is significant, since the stage of accidental wear of the headstand operating in a cryogenic environment differs from the stage of normal wear by the size of the resulting metal wear products. Therefore, to determine the early stages of the development of emergency wear, it is necessary to continuously control the size of the particles passing through the sensitive element. This requirement is fully met when using the proposed device. The tests will show that the proposed sensor has a sensitivity of 2j5 times more than what is known, and is capable of detecting metal inclusions. In a stream of cryogenic liquid 0.2 mm in size, i.e. over the mass of particles, the sensitivity increases by two orders of magnitude. Claims of a metallic inclusions sensor in a fluid flow comprising a housing and once meshed coaxially with it on a cylindrical frame, characterized in that, in order to increase the sensitivity, a sleeve with screw blades inserted coaxially with the housing is inserted into it, the output end of the sleeve is made - in the form of a fairing, the end of which coincides with the beginning of the winding, while the angle of elevation of the in-blade blades of the upper section lies within. and the height of the scales is determined from the ratio e - t) -c - s, where 8 is the height of the blades; T) - inner diameter of the housing; (3 is the diameter of the sleeve; C is the distance between the surface of the fairing and the inner surface of the framework. Sources of information taken into account during the examination 1. Copyright certificate CGGP No. 487362, class GOlN 3 / 1O, 05.1O.75.