Method of regulating the quality of a foam when it exits from a foam conveyor line

• US 4,676,926 A
• Filed: 07/10/1985
• Issued: 06/30/1987
• Est. Priority Date: 07/11/1984
• Status: Expired due to Fees

• Current Assignee: Laboratorium Prof. Dr. Rudolf Berthold Calmbacher
• Original Assignee: Laboratorium Prof. Dr. Rudolf Berthold
• Inventors: Kappler, Gerhard W.
• Primary Examiner(s): Lovering, Richard D.
• Application Number:
  US06/753,517
• Time in Patent Office: 720 Days
• Field of Search: 252/307, 261/DIG. 26, 134/34, 137/4, 222/55, 8/477
• US Class Current: 516/10
• CPC Class Codes: G05D 11/132 by controlling the flow of the individual components G05D11/133 takes precedence
• CPC Class Codes: Y10S 261/26 Foam
• CPC Class Codes: Y10T 137/0335 Controlled by consistency of mixture

Abstract

In a method for regulating the foam density in products foamed from liquid and a gas additive the density of the foam and the excess pressure are simultaneously measured in the conveyor line of the foam, correlated in an evaluation circuit and the free foam density, that is, the density of the released foam under atmospheric pressure, is calculated therefrom. This calculated value is compared with a set value of the free foam density and in the case of deviations the ratio of the amounts of liquid and gas conveyed is varied.

This method makes it possible for the relative fluctuation in density of the released foam to be reduced to values on the order of 1%.

Claims

1. A method for controlling the free foam density of a foamed product formed by combining a liquid of known density S_F and a gas in a mixing means and discharging through a foam conveyor line comprising:

(a) providing a means for introducing gas into a mixer;

(b) continuously measuring both the density S_s and the pressure P_u of a foam in immediately adjacent locations in a foam conveyor line;

(c) calculating the actual value S_L * for said free foam density S_L from the measurements of S_s and P_u according to the relationship ##EQU2## (d) comparing the actual value S_L * with the desired set value S_L ; and

(e) adjusting the means for introducing gas into the mixer to cause S_L * to be equivalent to S.sub..

2. A method for controlling the free foam density of a foamed product formed by combining a liquid and a gas in a mixing means and discharged through a foam conveyor line comprising:

(a) providing a regulator valve in a gas feed line leading to a mixer;

(b) continuously measuring the density of S_s of a foam in a foam conveyor line using a radiometric density measuring device;

(c) continuously measuring the pressure Pu in the foam conveyor line;

(d) calculating the free foam density S_L * from the density S_s and the pressure Pu in a microprocessor;

(e) comparing the free foam density S_L * with the desired set value S_L and determining in a microprocessor whether more or less gas is required; and

(f) signaling a means for controlling said regulator valve to adjust said valve to increase or to decrease the flow of said gas through said valve.