RU248U1 - Sensor for detecting oxygen in a liquid - Google Patents

Abstract

A sensor for detecting oxygen in a liquid, comprising a housing having tangential inlet and outlet openings located at different levels, electrodes installed in the housing, and current collectors, characterized in that the measuring and auxiliary electrodes are made in the form of half cylinders and together with their insulating insert form a cylindrical cavity into which a ball freely moving under the action of a controlled fluid is placed, the diameter of which is greater than or equal to the width of the insert, and the mass is selected from the ratio Mm = 4Q / (3, 3-4.6) * 10 ^ 7 * d * pi * nude), where Q is the second fluid flow rate, m / s; d is the inner diameter of the cylinder, m; nu - kinematic viscosity of the measured fluid, m / s.

Description

The utility model relates to measuring the content of gases in liquid media, in particular oxygen, and can be used to determine the oxygen in the deaerator water, in the preparation of water in boiler rooms, at thermal power plants and in gas distribution complexes,

Known measuring electrode system for determining the content of dissolved oxygen, containing placed in the housing, measuring and reference electrodes, an oxygen permeable membrane, which closes the measuring electrode so as to separate the electrode from the analyzed solution, the shaft connected to the electrodes, the electrolytic cell Q solution and the device for the rotation of the measuring electrode and the membrane (US Pat. J 4472261, ZhISHA / 27/46, ShI 204-402, publ. I8.Q9.84r.).

 Common signs of the known and claimed technical solutions are the presence of measuring and reference electrodes located inside the housing, as well as current collectors.

The disadvantages of the known system include the low expressivity due to the presence of a membrane through which only oxygen passes through diffusion and the low reliability due to the fact that only the measuring electrode is cleaned during operation and the membrane is not cleaned.

Also known is a device for measuring the partial pressure of oxygen in a liquid medium, comprising a cylindrical plexiglas body having openings located on two levels and directed tangentially to circular sections of the cylindrical body; in the upper part of the casing, a Clark electrode is mounted, which is a polarographic cell with a platinum P1ndsator electrode and a silver reference electrode lowered into the electrolyte and distant from the medium being measured by a gas-permeable membrane; in the lower part of the koraus there is a stirrer, driven by an electric motor with a magnet (AS USSR J 989444, M. cl. b; -01U2 / 48, publ. 15.01.83).

General for the well-known of the claimed devices is iia ЛЯЧЯ8 housing made of insulating material, suppressing the inlet and outlet tangentially directed holes located at different levels, and measuring and auxiliary electrodes with current collectors.

The known device does not exhibit expression. the transmission of oxygen of a controlled fluid through the membrane, introducing transport delay into the determination process, has low reliability due to the lack of a cleaning mechanism for the electrodes and the membrane. Moreover, the known device has less reliability due to the presence of rotating parts,

The task to which the claimed utility model is directed is to ensure the rapidity of a certain oxygen in a liquid, the reliability of its operation,

The problem is solved using a sensor containing a housing having an input and output tangential openings located at different levels, electrodes mounted in the housing, and current collectors,

Unlike the closest analogue in the claimed sensor, the measuring and auxiliary electrodes are made in the form of half cylinders and together with their insulating insert form a cylindrical cavity in which a ball is placed that moves freely under the action of a controlled fluid. The diameter of the ball is greater than or equal to the width of the insert, and its mass is selected from the ratio:

)-/about..;)

GL - second flow rate of fluid passing through the cylinder,

ei is the inner diameter of the cylinder, m;

 - constant equal to 3.14;

) is the kinematic viscosity of the measured fluid, bg / s;

The design of the measuring and auxiliary electrodes in the form of half-cylinders, forming a cylindrical cavity together with the insulating insert separating them, makes it possible to use a ball freely moving under the influence of a controlled fluid inside this cylindrical cavity to clean the working surfaces of the electrodes, which ensures high reliability of the sensor, also due to the exclusion of design of rotating parts.

centuries, the rate of which is much higher than the rate occurring in the membrane, which explains the increase in the express type of oxygen.

The claimed width zzoliruyuschih insides guarantees against short circuit between the electrodes when the fluid flow is stopped, thereby increasing reliability. The stated ratio for the mass booster determines the nature of its rotation between the electrodes; I provides reliable cleaning of the electrodes from salts precipitated in the liquid, and, therefore, the reliability of the sensor.

The mass of the ball is selected in the range determined by the coefficient (3.3–4.6) ω. For a coefficient value of less than 3.3th, the ball is heavy and does not rotate with a fluid stream, but more than 4th — it is ejected by the flow from the cylindrical cavity.

The sensor has no rotating parts, which increases the reliability of the sensor.

The essence of the claimed utility model is illustrated in the drawing, which shows a sensor for detecting oxygen in a liquid, in a section.

The sensor comprises a housing I with a cover J tightly closing it. The housing and cover may be made of insulating material, for example polypropylene. In the housing I, the measuring electrode 3 and the auxiliary electrode 4 are rigidly mounted, made in the form of half-cylinders, forming, together with the insulating insert 5, a cylindrical cavity. The measuring electrode can be made of silver, nickel or copper, and the auxiliary electrode is made of stainless steel or lead. The reference electrode 6 is hermetically mounted in the lid 2. Through hole I made through holes 7.8, located at different levels and having a tangential orientation. On the auxiliary electrode 4, a hole is also made, coaxial with the hole 7 in the housing I. Through the hole 7, controlled water is supplied to the cylindrical cavity of the sensor, and through the hole 8 is removed from the sensor.

A ball 9 is placed in the cylindrical cavity composed by electrodes 3 and 4, insert 5, the diameter of which is greater than or equal to the width of the insert, and the mass of the ball 9 is selected from the ratio:

X d d / Oi - sec is the second liquid flow rate in the cylinder, m / s; cylinder inner diameter, m; - constant equal to ЗД4 l) - kinematic viscosity of the controlled fluid, yg / s. In a real example, г 26 m, water consumption QL s 6.7 «10, kinematic viscosity) I 10 wr / s, the ball had a mass tl 10 kg. The electrodes 3, 4 and 6 have current collectors 10, II, and 12, respectively, connected to the measuring unit 13. In the case I, the inlet fitting 14 and the outlet 15 are sealed tightly. The sensor operates as follows, A constant flow of fluid is supplied to the case I through the nozzle 14. The fluid passes through an opening 7 in the housing I and the auxiliary electrode 4, tangentially filled and twisted in a cylindrical cavity. The energy of water is such that it picks up 9 and begins to rotate it, pressing it with centripetal force against the walls of the cylindrical cavity. Measuring and auxiliary electrodes 3 and 4 are cleaned of precipitated salts and solids. The diameter of the ball is greater than or equal to the width of the insert. Such an insert width protects the sensor from short circuit when the fluid flow stops, since the ball cannot close electrodes 3 and 4 if it accidentally gets between the shmi. A short circuit between the electrodes would lead to the failure of the measuring unit 13, the choice of the mass of the ball to the formula and the absence of rotating parts increases the reliability of the measurement. On the measuring electrode 3 relative to the reference electrode 6, the measuring unit 13 maintains a constant potential. When liquid is supplied to the sensor, a current arises between the measuring 3 and auxiliary 4 electrodes, the value of which is directly proportional to the oxygen content in the liquid. Oxygen molecules, being restored on the measuring electrode, provide this current. Liquid serves as the electrical connection between the electrodes.

Claims (1)

A sensor for detecting oxygen in a liquid, comprising a housing having tangential inlet and outlet openings located at different levels, electrodes installed in the housing, and current collectors, characterized in that the measuring and auxiliary electrodes are made in the form of half cylinders and together with their insulating insert form a cylindrical cavity into which a ball freely moving under the action of a controlled fluid is placed, the diameter of which is greater than or equal to the width of the insert, and the mass is selected from the ratio Mm = 4Q / (3, 3-4.6) * 10 ^ 7 * d * pi * nude), where Q is the second fluid flow rate, m / s; d is the inner diameter of the cylinder, m; nu - kinematic viscosity of the measured fluid, m / s.