Design and Investigation of Optical System of Pyrometer for Measuring Flux Radiation of Solid Particles in a Two-Phase Flow

Abstract

There has been improved the measuring instrument of control of oxygen expenditure of a gas torch with the use of a simple tool base which does not demand a high level of qualification of operator. The optical system of pyrometer has been developed and investigated. The pyrometer is designed to measure radiation flux of solid soot particles in a high-temperature two-phase flow. The operating range of spectrum is 0,5·10^–6 ... 1,1·10^–6 m.

At designing of the block scheme of a pyrometer it has been considered that the two-phase torch of a gas burner is a powerful thermal radiator. In the capacity of an emitter the self-radiation of a two-phase torch of a gas burner is used. So a method of thermal control has been defined as the passive one. For the purpose of simplification of the block scheme of a pyrometer the direct reception of optical radiation is used which represents the direct registration of energy falling on the receiver. As a result of it the simple and the reliable design of a pyrometer is gained.

Measurement of stream of radiant energy of corpuscles of carbon (of soot) is carried out in a narrow spectral band of electromagnetic waves (0,5·10^–6 ...1,1·10^–6 м) between emission bands of gases. The problem of an optical spectral filtration at selection of signals against hindrances is carried out by the selective receiver of a stream of radiation. The spectral sensitivity range of the receiver coincides with wave length of range of measurement of stream of radiation of energy of corpuscles of carbon (of soot). It gave the possibility not to use interference filters in optical system of pyrometer. Focusing of energy of radiation on receiver sensing element of radiation is carried out by an optical system. The elements of an objective-lens of the simplified pyrometer are pellucid lens, a diaphragm, the optical filter. As a lens material transparent glass of brand К8 is used. Calculation of a visual field of optical system is executed. Size of a platform of a boresighting accepted equal to d₂ = 5·10^–3 m. There has been carried out the calculation of focal lengths of an optical system (f₁ = 60·10^–3 м; f = 50·10^–3 м). The transmission coefficient of a quantity of radiant energy in a pyrometer optical system is equal to product of a transmission coefficient of a lens and a light filter transmission coefficient (t_о = 0,823)