SU376695A1 - All-Union - Google Patents

Description

one

The invention relates to the study of the physicochemical properties of materials.

The known devices for determining the permeability of elastic materials containing working and measuring chambers separated by the test sample, the working medium supply system and measuring means do not provide sufficient accuracy.

The proposed device differs from the well-known in that, in order to improve the accuracy, the working chamber is mounted in the measuring chamber and is equipped with a sample overlapping valve.

The drawing shows the proposed device.

The device consists of a working chamber / mounted in the measuring chamber 2, hermetically separated by sample 3, the integrity of which with large pressure drops in the chambers / and 2 is ensured by a porous partition 4 and a disk 5 with holes. The tightness of sample 3 is ensured by clamping its collar with ring b between case 7 of working chamber I and disk 5.

In the ring 6 there is an undercut with a seal 8 for the seat 9 of the shut-off valve, which is pivotally connected to the lever 10 rigidly connected to the brush //. On the stem there is a key 12 located in the groove 13 of the guide sleeve 14, in the outer part of which

there are seals 15, crimped with a nut 1B, providing a hermetic stem inlet // into the pneumatic cylinder 17 with the plunger 18.

The working / and measuring 2 chambers are connected by an annular collar 19, which is included in the recesses of the flange 20 of the measuring chamber 2 with the seal 21 and the lid 22 of the working chamber with the seal 23. The compression of the seals 21 and 23 is carried out by nuts 24 located on the studs 25 welded into the flange 20 measuring chamber 2.

In the working chamber / thermometer 26 is located to obtain negative and positive temperatures and remote

a temperature sensor 27 embedded in the cups 28 and 29 which are welded into the lid .22.

Two fittings 30 in the lid 22 of the working chamber connect its cavity with the feed system

medium by a pneumohydraulic system or with a vacuum line through an external distribution device.

The measuring chamber 2 is in communication with the pressure measuring device nozzle 31.

The device works as follows. The test sample 3 is fixed in the working chamber 1. The permeability of the sample is determined under evacuated chambers. First, the amount of air flowing in from the surrounding atmosphere through the walls is found.

housing and sealing into the cavity of the measuring chamber per unit of time from the moment of cutting off the measuring chamber 2 from the vacuum main. This procedure is performed with the valve 9 closed and open.

Then, the working chamber / predetermined medium is filled at the received pressure and, having set the required temperature, valve 9 is opened, and the total leakage of the medium per unit of time through the sample body and air through the walls and seals of the instrument is found. Measurement of pressure in the measuring chamber is carried out with the shut-off valve I closed, which eliminates the leakage during the measurement. Jff 22 20 The final result is determined from the data difference.

Pfedmett from Obratin et al.

A device for determining the permeability of elastic materials containing working and measuring chambers separated by a test sample, a working medium supply system and measuring means, characterized in that, in order to improve accuracy, the working chamber is mounted into the measuring chamber and provided with a sample overlapping valve. / 7 f 1 13 9 ...