RU1790553C - Metering injector for sample preparing unit - Google Patents

Abstract

Usage: measuring technique, in particular, devices for dispensing liquids, liquid solutions of salts, alkalis, acids and organic solvents for chemical, physico-chemical and biological analyzes. SUMMARY OF THE INVENTION: a syringe dispenser consists of a molded case, a glass cylinder with a piston, and hydraulic bypass valves, inlet and outlet mounted on the inlet and outlet openings of the housing, with a conduit connected to them. The hydraulic bypass valve consists of a housing, on both sides of which are screwed caps that tightly press the fluoroplastic cup and the fluoroplastic sleeve, on which the rubber tip is worn. The intake and drain pipes are sealed with rubber o-rings in the holes of the nut covers. 2 ill. (A C

Description

The invention relates to measuring technique, in particular, to devices for the selection and dispensing of liquids, including liquid solutions of salts, alkalis, acids and organic solvents, and can be used wherever chemical, physico-chemical and biological analyzes are required.

A bypass valve is known for dispensing the smallest doses of liquid, consisting of a cylindrical sleeve into which a pinch valve is inserted, the elastic ends of which act as a check valve and a discharge valve.

The specified device has the following disadvantages:

the elastic elements located at the ends of the valve valve during pinch create undesirable tension along the entire length of the valve, thereby affecting the change in volume and dosage error;

sticking and hardening during depressurization of the hydraulic system of the valve stem, which reduces the reliability of the bypass valve and causes the failure of the entire device.

The closest technical solution is an automatic burette-dispenser containing a drive mechanism,

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a metering device in the form of a cylinder with a piston, a distribution system with a shut-off valve connected via connecting pipelines, consisting of a housing with a shut-off and diaphragm element of the membrane type and inlet and outlet pipes, a titrant flow indicator, and a program setting device.

The disadvantages of this device is to achieve the tightness of the hydraulic lines due to the presence of a large number of mating elements, as well as the fuzzy operation of the shut-off valve with a differential pressure,

The aim of the invention is to improve the accuracy and reliability of the device.

The goal is achieved in that, in the syringe dispenser for the sample unit; a preparation containing a metering device in the form of a cylinder with a piston, a supply pipe and hydraulic

the bypass valves with shut-off by-pass elements according to the invention, the hydraulic by-pass valves are made in the form of built-in conical-shaped elements with through-holes and additional openings closed at the narrowed end located at the stranded end of the element perpendicularly and conjugate to the first opening, moreover, the built-in elements are equipped with elastic. tips. °

 : The implementation of the built-in element of the shut-off and start-up valve of the conical-shaped dispenser-dispenser makes it possible to reach an elastic tip when a nozzle is placed on it. of varying degrees of compression, at the base of the cone, the tip is pressed more tightly, hermetically, and less tightly at the other end. As a result, when the valve is working under pressure from the fluid that enters the valve at the narrow end of the element, the elastic tip extends and passes fluid. In the absence of pressure, the fluid does not pass, i.e. the valve is self-locking; liquid overflow; there is no bone. Thus, a more reliable operation of the shut-off valve system is achieved, which increases the accuracy of the dosed liquid and reduces the measurement error from ± 1% of the prototype to

± 0.5%;

Two hydraulic bypass valves installed on the syringe-dispenser accordingly will allow for a hydraulic system with self-locking and subsequent dispensing of the dosed liquid, depending on the operation of the unit, sample preparation in the sampling cycle, dispensing and discharge of a certain volume of doses.

Figure 1 presents a General view of the proposed device; Figure 2 shows the design of a hydraulic bypass valve. The device consists of a molded body 1, a metering unit in the form of a cylinder with a piston 2 and installed on the inlet and outlet openings of the body 1, two hydraulic bypass valves, inlet 3 and outlet 4 with an elastic pipe 5 connected to them. Valve 3 or 4 (Fig. , 2) consists of a housing 6, on both

The 5 sides of which are screwed on with nut covers 7 and 8, which hermetically presses the fluoroplastic cup 9 and the fluoroplastic conical shape of the sleeve 10 of the shut-off-over element, on which an elastic tip 11 is put on. Intake 12 and drain 13 nozzles made of an inert material (for example, fluoroplastic) fixed tightly with rubber o-rings 14 in the holes of the nut covers 7,

5 8. Inlet 3 and outlet 4 valves are connected to the intake 12 and drain 13 nozzles according to the hydraulic diagram. The sleeve 10 has a non-through central hole 15 extending along its horizontal axis until it mates with other holes 1.6 located perpendicular to the first through the tapered end of the sleeve. The device works in conjunction with DAJ-115 dispensers. 1-1.2 of all modifications5 tions. The syringe dispenser installed in a special recess in the dispenser housing, where the drive mechanism of the dispensing unit 1 is located. For creating a vacuum in the hydraulic valves of the syringe dispenser

0 12 and drain 13 nozzles of the elastic conduit 5 are lowered into glasses with dosing solutions. The drive mechanism operates in cyclic mode. Before starting work, the piston of the dosing unit 2

5 is in the up position. When lowering the piston in the cylinder 2, the liquid through the intake pipe 12 enters the inlet valve 3, while the elastic tip 11 under the pressure of the liquid is expanded, opening through the transverse holes 16 on the sleeve 10 and passes the liquid into the cavity of the cylinder 2. Upon return the piston in the upper position, the elastic tip 11 of the compression valve 3 is 5, closing the transverse holes 16 on the sleeve 10, the valve 3 is locked. The exhaust valve 4 begins to work, the elastic tip 11 of which is expanded under the pressure of the liquid, opening the through holes 16 on the sleeve 10 and the pass

fluid in drain pipe 13, etc. throughout the operation of the syringe dispenser.

In order that the aggressive medium (liquid) to be dosed does not react with valve parts, the cup 9, sleeve 10, tip 11, nozzles 12 and 13 are made of inert materials: fluoroplastic, polyvinyl chloride, rubber.

Using the invention allows:

0

increase the reliability of the device by achieving tightness, speed and self-locking of the two-valve system;

increase the dosage accuracy by 2 times; .

to make device parts from homogeneous materials, for example, fluoroplastic, which increases the efficiency of the device.

Claims (1)

Formula invented and A syringe dispenser for a sample preparation unit, comprising a metering device in the form of a cylinder with a piston, a supply pipe and hydraulic bypass valves with shut-off and bypass elements, characterized in that, in order to increase accuracy and reliability # / devices, hydraulic bypass valves are made in the form of built-in conical-shaped elements with through and additional holes muffled at the narrowed end located at the narrowed end of the element perpendicularly and mating to the first hole, and the built-in elements are equipped with elastic tips. AI #