Method and apparatus for adjusting the density of a liquid

• US 5,325,852 A
• Filed: 07/21/1993
• Issued: 07/05/1994
• Est. Priority Date: 07/21/1993
• Status: Expired due to Fees

• Current Assignee: Accurate Metering Systems Incorporated
• Original Assignee: Accurate Metering Systems Incorporated
• Inventors: Clem, Lyle W.
• Primary Examiner(s): Hepperle, Stephen M.
• Application Number:
  US08/095,665
• Time in Patent Office: 349 Days
• Field of Search: 137/3, 137/91, 137/101.19, 137/101.21
• US Class Current: 137/91
• CPC Class Codes: G05D 21/02 characterised by the use of electric means
• CPC Class Codes: Y10T 137/0335 Controlled by consistency of mixture
• CPC Class Codes: Y10T 137/2504 By specific gravity
• CPC Class Codes: Y10T 137/2529 With electrical controller

Abstract

A density controlled product with controlled overrun amounts is formed a method and an apparatus whereby a fluid stream is measured with a mass flow meter in order to develop a predetermined liquid metering density control system for mixing a liquid having a variable density with an injected gas or liquid to derive a resultant liquid of a desired constant density may be obtained.

Claims

1. An apparatus for adjusting the density of a liquid, the apparatus including a liquid mass flow meter, a fluid mass flow meter, a programmable logic controller and an operator interface;

the apparatus further comprising;

a) a means to determine a characteristic of a first liquid connecting the liquid mass flowmeter to the programmable logic controller;

b) a means for reading the characteristic of the first liquid connecting the programmable logic controller and the operator interface;

c) a means for feeding data from the liquid mass flowmeter and the fluid mass flowmeter to the programmable logic controller;

d) a means for combining the first liquid from the liquid mass flowmeter with a fluid from the fluid mass flowmeter to form a combined liquid;

e) a means for adjusting the characteristic of the combined liquid;

f) the characteristic being density;

g) the liquid mass flowmeter providing a control signal output;

h) the control signal output indicating an instantaneous density of the combined liquid, a mass rate of the combined liquid, and a volumetric flow rate of the flowing liquid;

i) the programmable logic controller being set to provide the combine liquid with a predetermined density;

j) the means for adjusting the characteristic of the combined liquid including means to adjust an amount of the fluid to have the combined liquid reach the predetermined density;

k) the characteristic further being density with a temperature compensation factor; and

l) the control signal output being a linearized current signal.

2. The apparatus of claim 1 further comprising the control signal output being a linearized four milliamperes to twenty milliamperes current signal.

3. The apparatus of claim 1 further comprising:

a) the characteristic further being density with a temperature compensation factor; and

b) the control signal output being a serially communicated value.

4. The apparatus of claim 1 further comprising:

a) the control signal output providing a second output for input to the programmable logic controller; and

b) the programmable logic controller having means to receive and convert any signal to a digital signal.

5. The apparatus of claim 4 further comprising:

a) the liquid mass flowmeter being installed in a piping system to measure the characteristics of a flowing liquid and continuously determine an instantaneous mass rate and the density of the liquid; and

b) the programmable logic controller having an operator interface to display real time data from the liquid mass flowmeter and the gas mass flowmeter.

6. The apparatus of claim 5 further comprising:

a) a signal converter being connected between the liquid mass flowmeter and the programmable logic controller to accept a frequency signal;

b) the signal converter being connected to an analog input module of the programmable logic controller; and

c) a density signal also being derived from the liquid mass flowmeter and connected to the analog input module of the programmable logic controller.

7. The apparatus of claim 6 further comprising:

a) the programmable logic controller including means to calculate a required volume of fluid to be injected into the liquid to form the combined liquid and to give the desired final product density; and

b) the liquid mass flowmeter providing data to calculate the required volume.

8. The apparatus of claim 7 further comprising the required volume being calculated by the formula ##EQU4## wherein:

a) Q is the actual density of the combined liquid gallon from the liquid mass flow meter;

b) F represents the volume of the combined liquid fluid mix being density compensated from the liquid mass flowmeter;

c) D represents the desired weight per unit volume; and

d) A represents the volume of fluid required in liters or gallons.

9. The apparatus of claim 8 further comprising:

a) a fluid mass control meter; and

b) the fluid mass control meter regulating an internal flow of fluid being used.

10. The apparatus of claim 9 further comprising:

a) a frequency scaler and a frequency to analog converter being connected between the liquid mass flow meter and the programmable logic controller;

b) the frequency scaler and the frequency to analog converter being connected between the fluid mass flow meter and the programmable logic controller;

c) a filter regulator being connected between a source for the first liquid and the liquid mass flow meter;

d) a solenoid valve being positioned between an outlet for the liquid mass flowmeter and the gas mass flow meter; and

e) the solenoid valve having a check valve between it and the gas mass flow meter.

11. The apparatus of claim 10 further comprising:

a) the programmable logic controller including a programmable controller computer unit, an ASCII basic module, discrete input module, an analog input module and an analog output module, and a discrete output module;

b) the discrete output module being connected by two standard control wires to the solenoid valve;

c) the analog output module being connected by a first set of two shielded cables to the gas mass flow meter controller;

d) the analog input module being connected by a second set of two shielded cables to the gas flow meter;

e) the analog input module being connected by a third set of two shielded cables to the frequency analog converter;

f) two control wires connecting the discrete input module to the frequency scaler;

g) a communication cable connecting the ASCII basic module to the operator interface keypad;

h) the frequency scaler being additionally connected to the frequency analog convertor and the mass flow meter transmitter;

i) the frequency analog convertor being connected to the mass flow meter transmitter; and

j) the flow meter transmitter communication cable connecting the mass flow meter transmitter to the liquid mass flow meter.

12. The apparatus of claim 11 further comprising:

a) a tubing assembly connecting the filter regulator at a first end to a clean, dry, instrument gas supply and at a second end oppositely disposed end to the gas mass flow meter;

b) the gas mass flow meter being connected to the solenoid valve;

c) the liquid mass flow meter includes a liquid inlet for measuring a density of the first liquid; and

d) the outlet permitting the first liquid to flow thereout after the density thereof has been tested.