CN2765180Y

CN2765180Y - A device for direct measurement of crude oil refractive index

Info

Publication number: CN2765180Y
Application number: CN 200420052820
Authority: CN
Inventors: 杨爱玲; 张京亮; 郑荣儿
Original assignee: Ocean University of China
Current assignee: Ocean University of China
Priority date: 2004-08-03
Filing date: 2004-08-03
Publication date: 2006-03-15
Anticipated expiration: 2014-08-03

Abstract

The utility model relates to a device for directly measuring the refractive index of crude oil, which is composed of an optical system forming bar-shaped light beams inward by a laser, a capillary pipe, an observing screen, a CCD camera and a computer which is connected with conducting wires, wherein the computer contains calculating programs; the capillary pipe is horizontally positioned; the axis of the capillary pipe is parallel to the axis of a cylindrical lens; the optical system and laser beams are kept coaxial. The optical system forming bar-shaped light beams is composed of a concave lens, a convex lens and the cylindrical lens; the front focuses of the concave lens and the convex lens are coincident; the bar-shaped light beams are irradiated and covered on the capillary pipe. Interference stripes generated by the device are carried out with image processing and the identification to interference stage number of stripes and the coordinates of all points of stripes by the computer; the computer can calculate the refractive index of crude oil by using the existing Abbe inverse transform formulas. The utility model has the advantages of simple structure, low cost, convenient operation, high precision and high measuring speed.

Description

A kind of device of direct measurement crude oil refractive index

Technical field

The utility model relates to a kind of interference technique of using up and directly measures low transparency crude oil refractive index, is a kind of device of direct measurement crude oil refractive index specifically.

Background technology

Refractive index is an important optical parameter to crude oil, calculating its special component, will using refractive index when measuring oil film thickness, also will use refractive index when some industrial processs are for example measured crude oil solubleness parameter.But because the transparency of crude oil is very little, traditional refraction method can't directly be measured its refractive index.When measuring the crude oil refractive index, must obtain transparent light constituent wherein, record the refractive index of these light constituents, then with the extrapolate refractive index of crude oil of these data with the method for refraction earlier with the crude oil fractionation with the apparatus and method of refraction.Also owing to can not record in the crude oil refractive index of low clear component with the method for refraction, thereby the refraction method measures being similar to of crude oil refractive index, and its measuring accuracy is near 10-4.In order to improve precision, must use the method for interfering, the document of measuring liquid refractive index based on the method for interfering is very many.Yet most method requires one with reference to sample, they otherwise can not be applicable to low transparent sample, or the device that uses is too complicated, and require meticulous calibration with many optical elements, thereby the cost height, it is big to measure difficulty.

Summary of the invention

The purpose of this utility model be to provide a kind of manufacture craft simple, with low cost, be suitable for commercialization production, measuring accuracy height, robotization height, the fireballing device that can directly measure low transparency crude oil refractive index, to solve the difficult problem that the crude oil refractive index can't directly be measured.

Fundamental measurement principle of the present utility model: as light source, the spatial alternation by light beam forms the kapillary that the bar shaped light beam irradiation fills crude oil with laser instrument, and light beam is enough wide, to cover the part of capillary midsection 4-5cm.Reference laser beam and the laser beam interference of passing through kapillary inside by the kapillary upper and lower form the visible interference fringe of human eye.This interference fringe directly and the direction at refraction angle perpendicular, thereby relevant with the refractive index of crude oil in the kapillary.Take interference fringe with high precision CCD camera, interference fringe machine is as calculated carried out digitized processing, to improve fringe contrast, accurately to determine the dried dried progression of penetrating of penetrating striped, adopt computer program to discern the coordinate of the maximum and the minimum brightness of interference fringes at different levels, just available existing Abbe inverse transformation formula calculates the refractive index of crude oil to be measured, and its precision is up to 5 * 10 ^-6

The utility model is made up of at the interior optical system that forms bar shaped light beam, the computing machine that is near kapillary and subsequent film viewing screen and the CCD camera the focal plane and contains calculation procedure laser instrument, and capillary water placing flat, its axle with cylindrical lens is parallel, and keeps or meet relevant optical principles such as optical system and laser beam be coaxial.

The optical system of above-mentioned bar shaped light beam is made up of concavees lens, convex lens and cylindrical lens, and concavees lens overlap with the front focus of convex lens, guarantee bar shaped light beam irradiation technically and cover on the kapillary, rather than a light pencil is penetrated on particular point capillaceous.This also is one of this apparatus features.

Use this device can directly measure the refractive index of low transparency crude oil, and this apparatus structure is simple, cost is low, and light path need not fine adjustment, and simple to operate, measuring speed is fast.

Description of drawings

Fig. 1 is a general structure synoptic diagram of the present utility model.

Fig. 2 is a structural parameters synoptic diagram of the present utility model.

Fig. 3 is a measurement schematic flow sheet of the present utility model

Wherein 1, laser instrument; 2, concavees lens; 3, convex lens; 4, cylindrical lens; 5, kapillary; 6, film viewing screen; 7, casing; 8, the CCD camera; 9, lead; 10, computing machine.

Embodiment

As accompanying drawing 1, shown in Figure 2, the utility model is made up of at the interior optical system that forms bar shaped light beam, the computing machine that is near kapillary 5 and subsequent film viewing screen 6 and the CCD camera 8 the focal plane and contains calculation procedure laser instrument 1, and kapillary 5 horizontal positioned, its axle with cylindrical lens is parallel, and keeps optical system and laser beam coaxial.

The optical system of above-mentioned bar shaped light beam is by concavees lens 2, and convex lens 3 and cylindrical lens 4 constitute, and concavees lens 2 overlap with convex lens 3 front focus, guarantees that technically bar shaped light beam shines and covers on the kapillary.Above-mentioned convex lens 3 can replace with plano-convex lens, to reduce device volume;

Laser instrument can replace with the green light of various continuous power outputs or semiconductor, gas or the solid state laser of ruddiness, but requires its output power greater than 10mw; The parallel beam that laser instrument sends is by the center of all optical components among Fig. 1.The focal length of concavees lens 2 is f ₁, the focal length of convex lens 3 is f ₂, concavees lens 2 overlap with the front focus of convex lens 3, and both spacings are f ₂-f ₁ Cylindrical lens 4 next-door neighbour's convex lens 3 are placed, and its focal length is f ₃The light beam that laser instrument sends is via 2,3, and 4 become bar shaped light beam, the part of this bar shaped light beam irradiation and covering capillary midsection 4-5cm.The capillary water placing flat, its axle with cylindrical lens is parallel.The extracapillary inside radius is than being advisable less than 1.5.Film viewing screen 6 is one to have the translucent screen of coordinate and scale, is d from kapillary centre distance.For reducing the influence of parasitic light, concavees lens 2, convex lens 3, cylindrical lens 4, kapillary 5, film viewing screen 6 is fixed in the casing 7.CCD camera 8 is fixed on the tripod, be used for taking interference fringe, the CCD camera is connected with computing machine 10 by lead 9, interference fringe is carried out Flame Image Process via computing machine, to strengthen fringe contrast, accurately determine the interference level of striped, the maximum of definite interference fringes at different levels and the coordinate of minimum brightness of programming of being not difficult, by the refractive index of Abbe inverse transformation formula calculating crude oil, it is measured flow process and sees Fig. 3.The utility model of constructing thus also can be used for the measurement of transparency liquid and other low transparency liquid refractivity, so the measurement range of its refractive index is wide.Be the precision that guarantees to measure, all samples all should be measured as suitable under constant temperature.

Claims

1 one kinds of devices of directly measuring the crude oil refractive index, it is characterized in that it by laser instrument (1) in the interior optical system that forms bar shaped light beam, be in the computing machine that contains calculation procedure (10) that near the focal plane kapillary (5) and subsequent film viewing screen (6) and CCD camera (8) link to each other with lead (9) and form, and kapillary (5) horizontal positioned, its axle with cylindrical lens is parallel, and keeps optical system and laser beam coaxial.

The device of 2 direct measurement crude oil refractive indexes as claimed in claim 1, the optical system that it is characterized in that above-mentioned formation bar shaped light beam is by concavees lens (2), convex lens (3) and cylindrical lens (4) are formed, and concavees lens (2) overlap with the front focus of convex lens (3), and bar shaped light beam irradiation and covering on the kapillary (5).

The device of 3 direct measurement crude oil refractive indexes as claimed in claim 2 is characterized in that above-mentioned concavees lens (2), convex lens (3), cylindrical lens (4), kapillary (5) and film viewing screen (6) to be fixed in the casing (7) and still keeps coaxial relation.

4 devices as claim 2 or 3 described direct measurement crude oil refractive indexes is characterized in that the available plano-convex lens of above-mentioned convex lens (3) replaces.

5 devices as claim 1 or 3 described direct measurement crude oil refractive indexes is characterized in that the outer inside radius ratio of above-mentioned kapillary (5) is less than 1.5.

The device of 6 direct measurement crude oil refractive indexes as claimed in claim 1 is characterized in that above-mentioned film viewing screen (6) is for having the translucent screen of coordinate and scale.

The device of 7 direct measurement crude oil refractive indexes as claimed in claim 1 is characterized in that the green light of the available various continuous power outputs of above-mentioned laser instrument (1) or the semiconductor laser of ruddiness, and its output power is greater than 10mW.

The device of 8 direct measurement crude oil refractive indexes as claimed in claim 1 is characterized in that above-mentioned laser instrument (1) can be gas or solid state laser, as the He-Ne laser instrument.