CN103162057B - Locating and sealing assembly of gas permeation pipe - Google Patents

Abstract

A locating and sealing assembly of a gas permeation pipe is composed of a bolt body, a nut body and a locating bolt. The gas permeation pipe is sleeved into the bolt body, the nut body matches with the bolt body to tightly press the gas permeation pipe, and the locating bolt locates and fixes the nut body and the bolt body so as to achieve a goal of sealing the permeation pipe. The locating and sealing assembly of the gas permeation pipe is used for preparing the permeation pipe and preparing trace standard gas.

Description

A positioning sealing component of a gas permeation tube

technical field

The invention belongs to the field of chemical analysis, and relates to a standard gas preparation device for liquid organic compounds at room temperature, in particular to a positioning and sealing component of a gas permeation tube.

Background technique

The permeation tube is usually a small device consisting of an inert polytetrafluoroethylene tube, which contains an organic compound in equilibrium in two phases (gas phase or liquid phase, solid phase), and the two ends are sealed with an adhesive. When the temperature is constant, the gas in the tube seeps out of the permeation tube at a constant rate. The device is placed in the carrier gas flow to provide calibration gas to calibrate the analyzer system, test the alarm point of hazardous gas, study the influence of materials and biochemical systems, etc. Permeation tubes are suitable for any occasion that requires stable ppb to ppm level trace gases. For example, VICI AG International's Dynacal permeation tube, related patents USP7269991, 4399942, 4958529, 4977776, 5239856, 5457983, 5665314 and Chinese patent 00214154.

The two ends of the permeation tube are usually sealed with adhesive, which requires a special adhesive and manufacturing process, and the use of adhesive also increases the possibility of standard gas pollution, so it is necessary to improve the sealing design of the two ends of the permeation tube.

Contents of the invention

The object of the present invention is to provide a positioning and sealing assembly for a gas permeation tube.

To achieve the above object, the technical solution adopted in the present invention is:

A positioning sealing assembly for a gas permeation tube, used for two-end sealing of the permeation tube, including a bolt body and a nut body;

The bolt body is composed of an upper gland, a cylinder with external threads in the middle, and an insertion part with a ring-shaped protrusion in the radial direction on the lower part; the axial section of the insertion part with a ring-shaped protrusion is an inverted isosceles trapezoid;

The nut body is a hollow round tube, the inner wall of the round tube is provided with an internal thread, and the lower part of the inner wall of the round tube is radially provided with an annular boss.

One end of the permeation pipe is inserted from the lower part of the nut body, and the insertion part of the bolt body extends into the permeation pipe; the bolt body and the nut body are screwed together through external and internal threads.

Axial positioning holes are correspondingly arranged on the gland of the bolt body and the nut body, and a positioning bolt is sheathed in the corresponding positioning hole, and the positioning bolt fixes the bolt body and the nut body through the positioning hole.

Compared with the prior art, the present invention realizes the sealing of the permeation tube through positioning and fixing the nut body and the bolt body, avoids loosening, and reduces the pollution that the adhesive may introduce into the standard gas.

Description of drawings

Further detailed description below in conjunction with accompanying drawings.

Fig. 1 is a schematic structural diagram of a positioning seal assembly of a gas permeation tube.

In the figure, 1. Bolt body, 2. Nut body, 3. Permeation tube, 4. Positioning bolt, 5. Positioning hole, 6. External thread, 7. Inserting portion with annular protrusion in radial direction, 8. Internal thread, 9. Annular boss.

Detailed ways

A positioning and sealing assembly for a gas permeation tube, which is composed of a bolt body, a nut body, and a positioning bolt. One end of the permeation tube is inserted from the lower part of the nut body, and the insertion part of the bolt body extends into the permeation tube; the bolt body and the nut body pass through the outer, The internal threads are screwed together, and the positioning bolt positions and fixes the nut body and the bolt body, so as to achieve the purpose of sealing the permeation pipe.

The number of positioning holes on the bolt body is 2-8; the number of positioning holes on the nut body is 2-8; the positioning bolt is inserted into the positioning hole to fix the nut body and the bolt body.

Example 1:

Using the positioning sealing assembly designed by the present invention, one end of the permeation pipe (3) is inserted from the bottom of the nut body (2), and the insertion part of the bolt body (1) extends into the permeation pipe (3); the bolt body (1) and the nut The body (2) is screwed together by external and internal threads. The positioning bolt (4) positions and fixes the bolt body (1) and the nut body (2) through the positioning hole (5), and then adds an appropriate amount of liquid acetone to the permeation tube (3).

Insert the other end of the permeation tube (3) from the bottom of the other nut body (2), and the insertion part of the other bolt body (1) extends into the permeation tube (3); the bolt body (1) and the nut body (2) ) are screwed together through external and internal threads. The positioning bolt (4) positions and fixes the bolt body (1) and the nut body (2) through the positioning hole (5), so as to realize the purpose of sealing the two ends of the permeation pipe.

Example 2:

Adopt the method described in Example 1 to prepare a gas permeation tube. The permeation tube is polytetrafluoroethylene with an inner diameter of 2 mm and a length of 5 cm. It contains acetone liquid. The permeation tube is installed in a casing with a carrier gas. The carrier gas is air, and when the flow rate is 330ml/min, the concentration of standard acetone gas obtained is 1ppm.

Example 3:

Adopt the method described in Example 1 to prepare a gas permeation tube. The permeation tube is polytetrafluoroethylene with an inner diameter of 4 mm and a length of 20 cm. It contains acetone liquid. The permeation tube is installed in a casing with carrier gas. The carrier gas is air, and when the flow rate is 100ml/min, the concentration of standard acetone gas obtained is 100ppm.

Example 4:

Adopt the method described in Example 1 to prepare a gas permeation tube, the permeation tube is polytetrafluoroethylene, with an inner diameter of 2 mm and a length of 5 cm, containing ammonia liquid, and the permeation tube is installed in a casing with carrier gas, the casing The carrier gas is air, and when the flow rate is 350ml/min, the concentration of standard acetone gas obtained is 5ppm.

Claims (2)

1. a location sealing assembly for gas permeation tube, for two end sealings of osmos tube (3), is characterized in that: comprise the body of bolt (1) and nut body (2);

The body of bolt (1) forms by the gland on top, the middle part insertion section order with band shape projection in externally threaded cylinder, bottom radial direction is affixed; The shaft section of insertion section band annular high spot is inverted isosceles trapezoid;

The pipe that nut body (2) is hollow, round tube inner wall face is provided with internal thread, and round tube inner wall bottom radial direction is provided with annular boss;

One end of osmos tube (3) is inserted from the bottom of nut body (2), and the insertion section of the body of bolt (1) is stretched in osmos tube (3); The body of bolt (1) and nut body (2) are screwed by outer, internal thread.

2. location sealing assembly according to claim 1, is characterized in that:

On the gland and nut body (2) of the body of bolt (1), correspondence is provided with axial locating hole respectively, be coated with pilot pin (4) in corresponding locating hole, the body of bolt (1) and nut body (2) are located fixing by locating hole (5) by pilot pin (4).