Chemical injection system

• US 6,208,913 B1
• Filed: 08/18/1997
• Issued: 03/27/2001
• Est. Priority Date: 06/25/1993
• Status: Expired due to Term

• Current Assignee: Milton Roy, LLC
• Original Assignee: YZ Systems, Inc.
• Inventors: Marshall, Stephen E., Zeck, Mark V.
• Primary Examiner(s): Cosimano, Edward R.
• Application Number:
  US08/999,932
• Time in Patent Office: 1,317 Days
• Field of Search: 481/95, 137/3, 137/88, 364/502, 700/266
• US Class Current: 700/266
• CPC Class Codes: G05D 11/132 by controlling the flow of the individual components G05D11/133 takes precedence
• CPC Class Codes: G05D 7/0676 by action on flow sources G05D7/0688, G05D7/0694 take precedence
• CPC Class Codes: Y10T 137/0329 Mixing of plural fluids of diverse characteristics or conditions
• CPC Class Codes: Y10T 137/2499 Mixture condition maintaining or sensing

Abstract

A system for injecting chemicals, e.g., odorants, from a chemical supply into a conduit or container includes three primary components, a pump for injecting the odorant, a metering device, and a programmable controller. The controller is preferably powered by a solar panel to facilitate use of the system in remote areas for long periods of time. A removable data carrier, such as a memory module, is connected to the controller to collect odorant system event data. The data carrier is removable from the controller and the data therein may be downloaded into an auxiliary audit computer for generation of summary audit reports. The system precisely monitors how much odorant is used per pump stroke and insures that the odorant injection rate remains constant irrespective of environmental or equipment variations which might otherwise cause inaccuracies in the measurement of odorant usage data and/or the fluctuation of the odorant injection rate.

Claims

1. A system for injecting a chemical from a chemical supply into a fluid containing system at a desired injection rate, comprising:

a pump having an inlet, and an outlet connectable to the fluid containing system, the pump having an adjustable stroke rate;

a meter supporting a predetermined volume of the chemical and having an inlet connected to receive the chemical from the chemical supply and an outlet for delivering the chemical to the inlet of the pump;

a level transducer for continuously monitoring a level of the chemical in the meter and generating a chemical level signal proportional thereto; and

a controller operative under the control of a program stored therein and responsive to the chemical level signal for generating a control signal for selectively altering the stroke rate of the pump to maintain the injection rate substantially constant over a predetermined time period.

2. The chemical injection system as described in claim 1 further including;

a flow rate transducer located in the fluid containing system for generating a flow rate signal proportional to the flow rate of the fluid in the fluid containing system; and

wherein the controller is also responsive to the flow rate signal to generate the control signal.

3. The chemical injection system as described in claim 1 further including;

a temperature transducer located in the meter for generating a temperature signal proportional to the temperature of the chemical in the meter; and

wherein the controller is also responsive to the temperature signal to generate the control signal.

4. The chemical injection system as described in claim 1 further including;

a flow rate transducer located in the fluid containing system for generating a flow rate signal proportional to the flow rate of the fluid in the fluid containing system;

a temperature transducer located in the meter for generating a temperature signal proportional to the temperature of the chemical in the meter; and

wherein the controller is also responsive to the flow rate signal and the temperature signal to generate the control signal.

5. The chemical injection system as described in claim 1 further including an expansion tank connected to the meter.

6. The chemical injection system as described in claim 1 further including an audit system for collecting chemical usage data.

7. The chemical injection system as described in claim 6 wherein the audit system includes a memory module for storing chemical injection event data, and an audit controller.

8. The chemical injection system as described in claim 1 further including means for supplying electrical energy to power the controller.

9. The chemical injection system as described in claim 8 wherein the means for supplying electrical energy is a solar panel.

10. A control system for delivering odorant from an odorant receptacle into a gas pipeline, comprising:

a level sensor monitoring a level of odorant in the receptacle and generating a first signal proportional thereto;

a flow sensor monitoring flow of the gas in the gas pipeline and generating a second signal proportional thereto;

a temperature sensor monitoring temperature of the odorant in the receptacle and generating a third signal proportional thereto;

a valve having a gas inlet, and an outlet, the gas inlet receiving gas diverted from the gas pipeline;

a controller receiving the first, second and third signals and in response generating a control signal that actuates the valve to control the delivery of odorant into the gas pipeline at a predetermined odorization rate; and

a memory storing data representing an amount of odorant delivered into the gas pipeline.

11. The system as described in claim 10 wherein the memory also stores audit trail data detailing performance of the control system over a given time period.

12. The system as described in claim 10 wherein the memory also stores data representing an odorization rate.

13. The system as described in claim 10 wherein the memory also stores data representing an alarm.

14. The system as described in claim 10 further including a computer connectable to receive a download of at least a portion of the data.

15. The system as described in claim 10 wherein the controller is a computer operating under the control of a program stored therein.

16. The system as described in claim 10 wherein the receptacle is an odorant meter.

17. The system as described in claim 10 wherein the level sensor is a linear displacement transducer.

18. A method for delivering odorant from an odorant receptacle into a gas pipeline, comprising the steps of:

monitoring a level of odorant in the receptacle and generating a first signal proportional thereto;

monitoring flow rate of the gas in the gas pipeline and generating a second signal proportional thereto;

monitoring temperature of the odorant in the receptacle and generating a third signal proportional thereto;

generating a control signal in response to the first, second and third signals;

controlling the delivery of odorant into the gas pipeline at a predetermined odorization rate as a function of the control signal; and

storing audit data generated as a result of delivery of the odorant.