Apparatus for slurrying powdered solids

• US 4,357,953 A
• Filed: 02/26/1981
• Issued: 11/09/1982
• Est. Priority Date: 02/26/1981
• Status: Expired due to Fees

• Current Assignee: Zimpro Passavant Environment Systems Incorporated
• Original Assignee: Sterling Drug, Inc. (GlaxoSmithKline PLC)
• Inventors: Patterson, Donald E.
• Primary Examiner(s): Cohan, Alan
• Application Number:
  US06/238,436
• Time in Patent Office: 621 Days
• Field of Search: 137/268, 137/624.18, 137/624.2, 137/624.13, 137/624.15, 137/88, 137/111, 137/238, 137/240, 422/261
• US Class Current: 137/88
• CPC Class Codes: B01F 23/59 Mixing systems, i.e. flow charts or diagrams
• CPC Class Codes: B01F 25/312 with Venturi elements; Details thereof
• CPC Class Codes: B01F 25/31243 Eductor or eductor-type venturi, i.e. the main flow being injected through the venturi with high speed in the form of a jet
• CPC Class Codes: B01F 35/1452 using fluids
• CPC Class Codes: B01F 35/20 Measuring; Control or regulation
• CPC Class Codes: B01F 35/21 Measuring
• CPC Class Codes: B01F 35/2113 Pressure
• CPC Class Codes: B65G 53/30 Conveying materials in bulk through pipes or tubes by liquid pressure
• CPC Class Codes: C02F 1/687 Devices for dosing solid compounds
• CPC Class Codes: G05D 11/132 by controlling the flow of the individual components G05D11/133 takes precedence
• CPC Class Codes: Y10T 137/2499 Mixture condition maintaining or sensing
• CPC Class Codes: Y10T 137/2564 Plural inflows
• CPC Class Codes: Y10T 137/4891 With holder for solid, flaky or pulverized material to be dissolved or entrained
• CPC Class Codes: Y10T 137/86445 Plural, sequential, valve actuations

Abstract

An apparatus for introducing powdered solids into a liquid stream at a controlled rate to form a slurry. Solids are metered to an eductor where they are educted into the liquid stream. An automatic cycle timer-controller purges eductor, hopper and piping of residual solids before solids flow is initiated, and following solids flow. Pressure sensors detect low water pressure and/or plugging, shutting off liquid and solids flow.

Claims

1. An apparatus for introducing powdered solids into a liquid stream at a controlled rate to form a slurry, comprising:

a vessel for storing powdered solids and from which solids flow is assisted by gravity;

metering means communicating with said storage vessel and controlling the flow rate of said solids from said vessel;

an eductor through which said liquid stream passes, having a pressure liquid inlet, suction inlet for introduction of said solids into the liquid, and outlet for discharging the slurry formed thereby;

a conduit for transporting said solids from said metering means to said eductor;

a first power actuated valve in said conduit;

a pressure liquid line connected to pressure liquid inlet of eductor;

a second power actuated valve in said pressure liquid line;

a first pressure sensor in said pressure liquid line;

a slurry discharge line from eductor outlet to a slurry using process;

a second pressure sensor in said slurry discharge line;

automatic cycle timer-controller means sequentially opening said second power actuated valve for a first predetermined time period, subsequently opening said first power actuated valve and activating said metering means, maintaining both said power actuated valves open and said metering means activated for a first controlled time period, subsequently closing first power actuated valve and deactivating said metering means for a second predetermined time period, subsequently closing said second power actuated valve, maintaining both power actuated valves closed and metering means deactivated for a second controlled time period, and thereafter, repeating automatic timer-controller sequence; and

automatic means for closing both power actuated valves and deactivating said metering means when said first pressure sensor measures pressure lower than a first preset value or when said second pressure sensor measures pressure higher than a second preset valve or when the measured pressure difference between the first and second pressure sensors is less than a third preset value.

2. An apparatus according to claim 1, wherein said first pressure sensor is upstream of said second power actuated valve in pressure liquid line.

3. An apparatus according to claim 1, wherein said first pressure sensor is downstream of said second power actuated valve in pressure liquid line, and said sensor is activated, with time delay, when said second power actuated valve is opened.

4. An apparatus according to claim 1, wherein said first controlled time period is preset.

5. An apparatus according to claim 1, wherein said first controlled time period is determined by said automatic cycle timer-controller according to measured requirement of said slurry using process.

6. An apparatus according to claim 1, wherein said second controlled timer period is preset.

7. An apparatus according to claim 1, wherein said second controlled time period is determined by said automatic cycle timer-controller according to measured requirement of said slurry using process.

8. An apparatus according to claim 1, wherein solids metering rate of said metering means is controlled continuously or semi-continuously according to measured requirement of said slurry using process.

9. An apparatus according to claim 1, in which the metering means comprises a rotary valve for feeding and metering said powdered solids.

10. An apparatus according to claim 1, wherein said pressure sensors are pressure switches.

11. An apparatus according to claim 1, wherein the powdered solids are powdered activated carbon.

12. An apparatus according to claim 1, wherein said conduit between said metering means and said eductor is enlarged in cross-section to be a cone shaped hopper for solids passing to said eductor.

13. An apparatus according to claim 12, wherein said hopper has one or more orifices in its upper section allowing passage of air into said hopper at a rate which fluidizes said solids at said suction inlet while maintaining a partial vacuum within said hopper.

14. An apparatus according to claim 12, further comprising a vacuum sensor which measures the vacuum level in said hopper;

and

automatic timer-controller means closing first power actuated valve and deactivating said metering means when vacuum sensor measures a vacuum level less than a fourth preset value.

15. An apparatus according to claim 14, wherein said vacuum sensor is a vacuum switch.

16. An apparatus according to claim 12, further comprising a sensor measuring the liquid level in said hopper;

and automatic timer-controller means closing first power-actuated valve and deactivating said metering means when said liquid level sensor measures a level higher than a fifth preset value.

17. An apparatus according to claim 16, wherein said liquid level sensor is a switch controlled by the liquid level.

18. An apparatus according to claim 1, further comprising:

a drain pipe communicating with discharge slurry line, and having a third power actuated valve therein; and

automatic timer-controller means opening said third power actuated valve when the measured pressure difference between the first and second pressure sensors is lower than a sixth preset value or when second pressure sensor measures a pressure exceeding a seventh preset value.