Apparatus for determining the gas content of a liquid

• US 4,365,505 A
• Filed: 07/02/1980
• Issued: 12/28/1982
• Est. Priority Date: 07/18/1979
• Status: Expired due to Term

• Current Assignee: Kraussmaffei AG
• Original Assignee: Kraussmaffei AG
• Inventors: Holzl, Emil
• Primary Examiner(s): Gill, James J.
• Application Number:
  US06/165,397
• Time in Patent Office: 909 Days
• Field of Search: 73/19, 73/599, 264/40.1, 264/50
• US Class Current: 73/19.1
• CPC Class Codes: G01N 33/442 Resins, plastics
• CPC Class Codes: G01N 7/00 Analysing materials by measuring the pressure or volume of a gas or vapour

Abstract

Disclosed are a method of and an apparatus for determining entrained gas content in a liquid, especially a liquid synthetic-resin component adapted to form a foamed or cellular synthetic-resin body. Pressure pulses are applied to the liquid and pressure oscillations therein are detected, the amplitude Δp and/or the phase position of a peak being detected and evaluated to give the gas content. The determination may be used to control the addition of the gas to the liquid and/or can be displayed to permit operator control of the system.

Claims

1. An apparatus for determining the gas content of a liquid, comprising:

pump means for generating a pulsating stream of a gas-containing liquid in a flow channel;

detector means disposed at said flow channel downstream of said pump means and responsive to the pulsations in the pulsating stream produced by said pump means for generating an intermediate signal indicative of the pressure-propagating characteristics of the liquid/gas mixture flowing in said channel;

electronic processing means connected to said detector means and preprogrammed with at least one characteristic curve for converting said intermediate signal into an output signal corresponding to a predetermined parameter representing the proportion of gas in said liquid; and

a load responsive to said output signal connected to said processing means.

2. An apparatus as defined in claim 1 wherein said load comprises display means for visually indicating the magnitude of said parameter.

3. An apparatus as defined in claim 1 wherein said channel is connected to an adjustable source of gas to be continuously introduced into the liquid, said load comprising comparison means connected to a control input of said source for varying the rate of gas introduction to compensate for deviations of said output signal from a given set-point value.

4. An apparatus as defined in claim 1, 2 or 3 wherein said processing means is switchable among a plurality of stored characteristic curves plotted for different mean pressures.

5. The apparatus defined in claim 1, 2 or 3 wherein said detector means is a piezoelectrical element.

6. The apparatus defined in claim 1, 2 or 3 wherein said detector means is a strain-gauge element.