Precision liquid addition device

• US 5,558,249 A
• Filed: 09/19/1994
• Issued: 09/24/1996
• Est. Priority Date: 05/05/1993
• Status: Expired due to Fees

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Falcoff, Allan F.
• Primary Examiner(s): Kashnikow, Andres
• Assistant Examiner(s): Derakshani, Philippe
• Application Number:
  US08/306,426
• Time in Patent Office: 736 Days
• Field of Search: 222/144.5, 222/148, 222/318, 222/424, 222/63, 222/255, 222/145.1
• US Class Current: 222/63
• CPC Class Codes: B01F 2101/30 Mixing paints or paint ingredients, e.g. pigments, dyes, colours, lacquers or enamel
• CPC Class Codes: B29B 7/7615 characterised by arrangements for controlling, measuring or regulating, e.g. for feeding or proportioning the components

Abstract

An apparatus for delivering an accurate volume of fluid from a supply vessel to a process vessel or system in which a computer-controlled servo motor and pump are connected with a modified sampling valve with plunger-type injection device to allow complete addition of all metered fluids. The apparatus is particularly useful for addition of pH or viscosity control additives or shading colorants wherein the delivery of small volumes with precision is desired.

Claims

1. An apparatus for delivering a controlled volume of fluid from a supply vessel to a high pressure stream which comprises:

(a) at least one liquid supply vessel;

(b) a positive displacement means capable of delivering a variable volume of fluid from said supply vessel;

(c) controlling means coupled to said positive displacement means which drives said positive displacement means;

(d) a computer capable of storing programs electrically connected to said controlling means;

(e) an injection valve having three ports, wherein a first port receives fluid from said supply vessel, a second port attached to said first port allows said fluid to flow out of said injection valve into a process line and a third port which allows fluid to flow to a recirculation line;

(f) a plunger in said injection valve being positioned within said injection valve such that fluid may enter the space within said injection valve, said plunger acting as a syringe to perform air-free and complete addition of materials at the completion of the pumping cycle;

(g) a solenoid controlled by the computer to a position to allow circulation of fluids from said supply vessel through said injection valve back to said supply vessel to prevent settling of suspended particles within said fluids;

wherein said computer through the controlling means drives the positive displacement means to pump a volume of fluid from said supply vessel into said injection valve as the plunger is in the open position such that pumped fluids enter said process stream.

2. Apparatus as claimed in claim 1 wherein said computer is a digital computer having a keyboard input.

3. Apparatus as claimed in claim 1 wherein said computer has input from a second computer.

4. Apparatus as claimed in claim 1 wherein said injection valve is a sampling valve having a standard side port and a second liquid port in said standard side port.

5. Apparatus as claimed in claim 1 wherein said controlling means further comprises:

(a) a servo motor connected to said positive displacement means;

(b) a resolver connected to said servo motor for measuring angular rotation and motor speed of said positive displacement means within said servo motor; and

(c) a motor controller amplifier means electrically connected to said resolver which receives a signal on angular rotation from said resolver and thereby computes motor speed to control the servo motor and output of said positive displacement means.

6. An apparatus for delivering a controlled volume of fluid from a supply vessel to a high pressure stream which comprises:

(a) at least one liquid supply vessel;

(b) a positive displacement means capable of pumping a variable volume of fluid from said supply vessel;

(c) controlling means coupled to said positive displacement means which drives said positive displacement means;

(d) a computer capable of storing programs electrically connected to said controlling means;

(e) an injection valve having three ports, wherein a first port receives fluid from said supply vessel, a second port attached to said first port allows said fluid to flow out of said injection valve into a process line and a third port which allows fluid to flow to a recirculation line;

(f) a plunger in said injection valve being positioned within said injection valve such that fluid may enter the space within said injection valve, said plunger acting as a syringe to perform air-free and complete addition of materials at the completion of the pumping cycle;

(g) a solenoid controlled by the computer to allow circulation of fluids from said supply vessel through said injection valve back to said supply vessel to prevent settling of suspended solids within said fluids;

(h) a conduit which carries fluids to flush a supply line connected to said process stream whose flow is controlled by a second solenoid controlled by said computer;

wherein said computer through the controlling means drives the positive displacement means to pump a volume of fluid from said supply vessel into said injection valve as the plunger is in the open position such that pumped fluids enter said process stream, said plunger returns to said closed position, said second solenoid opening to allow fluids from said conduit to enter.

7. Apparatus as claimed in claim 6 wherein said computer is a digital computer.

8. Apparatus as claimed in claim 6 wherein said controlling means is

(a) a servo motor connected to said displacement means;

(b) a resolver connected to the motor for measuring angular rotation of displacement means within said motor; and

(c) a motor controller amplifier means electrically connected to a resolver which receives a signal on angular rotation from said resolver and thereby controls the motor and output of said positive displacement means.