US20150345516A1

US20150345516A1 - Vacuum assisted pump with integrated instrumentation and control system for slurry, sludge and solid laden fluids

Info

Publication number: US20150345516A1
Application number: US14/649,431
Authority: US
Inventors: Eric Fisher
Original assignee: THUNDER PROCESS GROUP
Current assignee: THUNDER PROCESS GROUP
Priority date: 2012-12-04
Filing date: 2013-03-15
Publication date: 2015-12-03
Also published as: CA2932165A1; WO2014085919A1

Abstract

Pump system for pumping a fluid product including slurry, sludge or solid laden fluids. It includes a pump body for receiving the fluid product with a product inlet and a product outlet with respective one-way check valves; a liquid inlet for communicating a liquid source with the pump body; a vacuum inlet for communicating a vacuum source with the pump body; a product detector for detecting at least one parameter of the fluid product inside the pump body; and a control system for controlling operation of the liquid source, the vacuum source and the product detector. The product detector includes a radio frequency level detector for detecting a level of the fluid product inside the pump body by emitting radio frequency signals that are received by the control system.

Description

FIELD OF THE INVENTION

The present invention relates to pumps for pumping slurry, sludge, solid laden fluids that are generally difficult to displace. More specifically, the present invention is related to a vacuum assisted pump with an integrated instrumentation and control system for pumping such fluids.

BACKGROUND OF THE INVENTION

Known in the art, there are vacuum assisted pumps used for pumping slurries having a pump body with a lower portion having inlet and outlet check valves. An air nozzle is positioned in an upper portion of the pump body to selectively establish any desired vacuum level and flow rate by means of a control circuit using opto-electronic liquid level sensors. An example of such a pump is disclosed in U.S. Pat. No. 5,007,803 by DiVito et al.
However, such know vacuum assisted pumps for slurries have the disadvantage that their sensors become clogged or dirty during use, which forces operators to clean regularly the inside of the pump, using substantial amounts of water and causing downtime. Furthermore, those known pumps also do not allow adjusting the thickness of the slurry inside the pump body.
There is a need in the market for a vacuum assisted pump that is less prone to clogging, is easier to clean, uses less water and could adjust the thickness of the slurry.

SUMMARY OF THE INVENTION

More specifically, in accordance with the present invention, there is provided a pump system for pumping a fluid product including slurry, sludge or solid laden fluids, comprising : a pump body for receiving the fluid product, the pump body having a product inlet and a product outlet with respective one-way check valves; a liquid inlet for communicating a liquid source with the pump body; a vacuum inlet for communicating a vacuum source with the pump body; a product detector for detecting at least one parameter of the fluid product inside the pump body; and a control system for controlling operation of the liquid source, the vacuum source and the product detector; wherein the product detector comprises a radio frequency level detector for detecting a level of the fluid product inside the pump body by emitting radio frequency signals that are received by the control system.
In accordance with another aspect of the present invention, there is provided a pump system for pumping a fluid product including slurry, sludge or solid laden fluids, comprising: a pump body for receiving the fluid product, the pump body having a product inlet and a product outlet with respective one-way check valves; a liquid inlet for communicating a liquid source with the pump body; a vacuum inlet for communicating a vacuum source with the pump body; a product detector for detecting at least one parameter of the fluid product inside the pump body; and a control system for controlling operation of the liquid source, the vacuum source and the product detector; wherein the liquid inlet is in communication with a liquid spray device inside the pump body.
Preferably, the liquid spray device comprises a water spray ball for cleaning the inside of the pump body or adjusting a thickness of the fluid product.
In embodiments, the pump system operates as follow: compressed air is used to generate vacuum, which draws product into the pump body until an internal sensor detects when the pump body is full. When full, the vacuum is stopped and compress air is used to push the product out of the pump system for a user set time by a timer control. When the discharge timer is complete, the compressed air is stopped and vacuum/compressed air cycle repeats.
Preferably, the pump system uses only two mechanical wear/service parts i.e. the inlet and outlet check valves. Preferably, the check valves are metal check valves which feature a knife edge cutting seat that is designed to cut soft solids to ensure sealing during closing operation. The check valves do not require mechanical closing assistance. The check valves include a self-adjusting flap alignment to assist with flap closure.
Advantageously, the pump system of the present invention has a sealless, minimum maintenance design. The pump system does not require rotating shafts or sliding parts to seal. It requires no motors, shafts, seals, bearings, gearboxes or other rotating, sliding or close fitting wear parts.
Advantageously, the pump system of the present invention allows water conservation. Indeed, the pump system transports any flowable or semi-flowable material with little or no water addition.
In embodiments, the pump system features automatic cleaning, wherein sensors detect when cleaning is required and automatically clean the system with water.
In embodiments, the pump system features automatic slurry thickness adjustment. Slurry thickness (viscosity) is automatically monitored and adjusted to maintain pump ability. Water is automatically added only when necessary.
In embodiments, the pump system features automatic energy conservation. Automatic shut off if no product available to pump; automatic restart when product is available.
In embodiments, the pump system features automatic or manual purge function to evacuate and flush discharge piping or for product recovery.
Advantageously, the pump system of the present invention features large size solids passing capability. It is adapted to receive pump pipeline-size solids through the system. For example a 100 mm (4″) unit passes a 100 mm (4″) solid.
In embodiments, the pump system is able to operate “dry” (no fluid or slurry present) continuously without damage.
In embodiments, the pump system requires approximately ¼ the floor space of traditional pump equipment.
In embodiments, the pump system can be used in place of, or to replace traditional equipment including:—Positive displacement pumps such as: progressive cavity pumps, lobe/rotary piston pumps, peristaltic hose pumps, reciprocating piston pumps, gear pumps, Sine pumps, etc.;—Centrifugal pumps where water is added to fluidize product for pumping (the present pump system requires little or no water);—Screw augers and conveyors; and Manual transport systems such as forklift totes and bins.
Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of specific embodiments thereof, given by way of example only with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the appended drawings:

FIGS. 1A and 1B are schematic diagrams of the instrumentation configuration of a vacuum assisted pump with integrated instrumentation and control system, according to a preferred embodiment of the present invention;

FIG. 2A is a perspective of a vacuum assisted pump with integrated instrumentation and control system, according to a preferred embodiment of the present invention;

FIG. 2 is a front elevation view of the vacuum assisted pump shown in FIG. 2

FIG. 3 is a left side elevation view of the vacuum assisted pump shown in FIG. 2;

FIG. 4 is a right side elevation view of the vacuum assisted pump shown in FIG. 2;

FIG. 5 is top view of the vacuum assisted pump shown in FIG. 2;

FIG. 6 is section perspective view of part of the vacuum assisted pump shown in FIG. 2; and

FIG. 7 is a perspective view of a one-way flap check valve shown in FIG. 6.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The present invention is illustrated in further details by the following non-limiting examples.
The table below refers to the elements illustrated in FIGS. 1A and 1B.


Item
Number	Description

1	Electronic Programmable Logic Controller (PLC)
2	Discharge Air Pressure Regulator
3	Air Valve - 2-way: Vacuum Generator
4	Air Valve - 3 way: Discharge Pressure/Vacuum Flow Switching
	Valves

5	Air/Vacuum Valve - 2-way: Main Off-On Valve
6	Discharge Pressure Monitor Switch
7	Vacuum Generator
8, 8′, 8″	Water Valve: Water Inlet On/Off; Water inlet check valve;
	Water Inlet
9	Radio Frequency Product Detector with adjustable sensitivity
10, 10′	Discharge Air Diffuser/Vacuum Inlet
11	Water inlet/cleaning 360 degree spray ball
12	Product Inlet Check Valve
13	Product Outlet Check Valve
14	Pump Body
15, 15′	Product Inlet and Outlet Check Valves

Referring to FIGS. 1A and 1B, there is shown a schematic diagram of a vacuum pump system with an integrated control system, according to a preferred embodiment of the present invention.
Referring to FIGS. 2 to 6, there is shown an embodiment of a vacuum pump system with an integrated control system corresponding to the schematic diagrams of FIGS. 1A and 1B.
According to a preferred embodiment, the pump system for pumping a fluid product including slurry, sludge or solid laden fluids, includes: a pump body 14 for receiving the fluid product, the pump body having a product inlet 12 and a product outlet 13 with respective one-way check valves; a liquid inlet 8″ for communicating a liquid source with the pump body 14; a vacuum inlet 10′ for communicating a vacuum source with the pump body 14; a product detector 9 for detecting at least one parameter of the fluid product inside the pump body; and a control system 1 for controlling operation of the liquid source, the vacuum source and the product detector 9; wherein the product detector comprises a radio frequency level detector for detecting a level of the fluid product inside the pump body by emitting radio frequency signals that are received by the control system 1.
The radio frequency level detector 9 may include a radio frequency point-level switch made by Babbit International from Houston, Tex. Babbit International point level switches models include LS2000 Low-Cost Sensor, LS600 Basic Feature Sensor, LS7000 dual-point sensor, LS8000 multi-point Sensor with Remote Electronics and MLS-4EX Multi-Point Float Level Switch.
As best illustrated in FIGS. 1A, 1B and 3, the liquid source W, such as water, is connected to the water valve 8, which is in turn electrically connected to the control system 1 or electronic programmable logic controller 1. The water valve 8 is connected to a water inlet check valve 8′, preferably via a flexible hose H. The inlet check valve 8′ is connected to the water spray ball 11 via water inlet 8″. The water inlet check valve 8′ is used to prevent discharge air pressure from being blown back to the water inlet 8″ when both are open. Indeed, this is useful as often air pressure can exceed water pressure.
As best illustrated in FIGS. 1A, 1B and 2A the vacuum inlet 10′ is connected to a pneumatic air inlet assembly including a main two-way main off-on valve 5, which is electrically connected to the electronic programmable controller 1. The main off-off valve 5 is connected to a three-way valve 4, which is electrically connected to the electronic programmable controller 1. A pressure monitor 6, which is electrically connected to the electronic programmable controller 1, is connected between the main-of-on valve 5 and the three-way valve 4. The three-way valve 4 is connected to a vacuum generator 7 and to an air pressure regulator 2, which is connected to an air supply. The vacuum generator 7 is also connected to a two-way valve 3, which is connected to the air supply. The two-way valve is electrically connected to the electronic programmable controller 1. Persons skilled in the art will understand that electrical connections include wireless connections.
According to another preferred embodiment, the pump system for pumping a fluid product including slurry, sludge or solid laden fluids, includes: a pump body 14 for receiving the fluid product, the pump body having a product inlet 12 and a product outlet 13 with respective one-way check valves; a liquid inlet 8″ for communicating a liquid source with the pump body 14; a vacuum inlet 10′ for communicating a vacuum source with the pump body 14; a product detector 9 for detecting at least one parameter of the fluid product inside the pump body; and a control system 1 for controlling operation of the liquid source, the vacuum source and the product detector 9; wherein the liquid inlet 8 is in communication with a liquid spray device 11 inside the pump body 14.
Referring to FIGS. 1A, 6 and 7, the pump system includes two one- way check valves 15, 15′ associated with their respective product inlet 12 and product outlet 13. Each check- valve 15, 15′ may include circular metal flap mounted on a relatively loose fitting and retained by a pin that is not fixed but floating. The flap abuts against a metal seat that has a cutting edge to achieve proper sealing, which is especially useful with thick slurry or fluids containing solids.

General Operation

All operations are controlled via #1 PLC with three operation modes: OFF/ON/PURGE.
OFF: #5 valve unpowered (closed) to isolate #14 pump body from air/vacuum distribution system. All operational functions are disabled
ON: Pump system operates automatically. #5 valve powered (open).

- Operation sequence:
  - SUCTION (vacuum condition) #9 product detector indicates no product in pump body.
    - #3 valve opens to supply compressed air to #7 vacuum generator
    - Vacuum is generated in #14 pump body by removing air though #10 air diffuser, #5 valve, #4 valve and #7 vacuum generator.
    - #13 check valves closes
    - #12 check valve opens to allow product into #14 body
    - Product enters #14 body until product contacts # 9 product detector
  - DISCHARGE (pressure condition) #9 product detector indicates product in pump body.
    - #3 valve closes
    - #1 PLC internal programmed delay timer is activated.
    - Delay time times out
    - #1 PLC internal discharge timer is activated and #4 valve is powered to supply compressed air at pressure regulated by #2 air pressure regulator to the pump body through #4 valve, #5 valve and # 10 air diffuser.
    - #12 valve closes
    - #13 valve opens
    - #6 pressure monitors switch monitors discharge pressure. If user set high discharge pressure is detected (pressure switch closes) see AUTOMATOC ON-DEMAND SLURRY THINNING sequence.
    - #1 PLC internal discharge timer times out.
    - #4 valve unpowered (closed)
    - #1 PLC internal programmed delay timer is activated.
    - Delay timer times out.
    - If #10 product detector immediately indicates product in the pump body see AUTOMATIC ON-DEMAND CLEANING sequence, else
    - Operation sequence repeats
- PURGE: Places pump system in DISCHARGE mode until manually stopped. Three purge modes available: Air only, Water only, Air and Water
  - Air Only (typically used for discharge line product evacuation and/or recovery)
    - #3 valve closed (if open)
    - #1 PLC internal programmed delay timer is activated.
    - Delay time times out
    - #4 valve is powered open to supply compressed air at pressure regulated by #2 air pressure regulator to the pump body through #4 valve, #5 valve and # 10 air diffuser.
    - #12 valve closes
    - #13 valve opens
    - Operation sequence continues until mode is changed by the operator to OFF or ON
  - Water Only (typically used for manual # 14 pump body cleaning)
    - #3 valve unpowered (closed)
    - #4 valve unpowered (closed)
    - #5 valve unpowered (closed)
    - #8 valve opened to supply water into #14 pump body through #11 spray ball.
    - #12 valve closes
    - #13 valve opens
    - Operation sequence continues until mode is changed by the operator to OFF or ON
  - Air and Water (typically used for cleaning and discharge line product evacuation simultaneously)
    - #3 valve closed (if open)
    - #1 PLC internal programmed delay timer is activated.
    - Delay time times out
    - #4 valve is powered open to supply compressed air at pressure regulated by #2 air pressure regulator to the pump body through #4 valve, #5 valve and # 10 air diffuser.
    - #8 valve opened to supply water into #14 pump body through #11 spray ball.
    - #12 valve closes
    - #13 valve opens
    - Operation sequence continues until mode is changed by the operator to OFF or ON

Water Conservation Technology

Automatic On-Demand Slurry Thinning

With many difficult to pump products, water is frequently added to the product to increase its ability to be pumped. Most often the product is close to un-flowable. Such products would require specialized pumping or conveyor systems to transport them. Adding water to the product “thins” the product to provide a more flowable consistency.
In all pumping systems, water would be added externally to the pumping system, most often continuously whether it is needed or not.
The vacuum assisted pump technology of the present invention utilizes two methods to reduce water demand for slurry thinning:

- On-demand air injection directly into the pump body
- on-demand water addition directly into the pump body
  Automatic On-Demand Slurry Thinning is engaged when #6 pressure monitor switch is activated.

Operation Sequence

- Air Injection
  - During DISCHARGE sequence # 6 pressure monitor switch is activated when discharge pressure exceed user set pressure setting (e.g. 60 psi).
  - #1 PLC programmed discharge time is extended by user set extended time.
  - DISCHARGE timer times out and resets to normal operation
  - SUCTION sequence begins
  - #6 pressure monitor switch resets
- Water Addition
  - During DISCHARGE sequence # 6 pressure monitor switch is activated when discharge pressure exceed user set pressure setting (e.g. 60 psi).
  - DISHARGE sequence complete
  - #1 PLC internal water addition timer is activated
  - #8 water opens to add water into the pump body
  - Water addition timer times out
  - #4 valve is powered to open for a preset time to clear any water in the air/vacuum line
  - #4 valve is unpowered to close
  - SUCTION sequence begins
  - #6 pressure monitor switch resets
    Operator has the choice to use air only, water only or both to maintain product pumpability. Typically air would be injected first. If, after a user settable number if cycles, air demand continues, the water addition sequence activates.
    Slurry thinning continues until #6 pressure monitor switch is not activated during a discharge cycle.

Automatic On-Demand Cleaning

Certain type of products with a viscous to “sticky” consistency will eventually coat the interior of the pumping system. To prevent this product build-up is monitored by the #9 radio frequency product detector.
The radio frequency product detector detects if product build-up (sticks) to a metal rod. The radio frequency is adjustable for sensitivity. Higher sensitivity allows less build-up before activating the cleaning cycle.
The cleaning sequence is activated when at the end of the discharge sequence the suction sequence resumes and immediately returns to the discharge sequence. This indicates product coating on the #9 radio frequency product detection rod.

Operation Sequence

- #3 valve powered open
- #1 PLC suction timer activated
- #3 valve unpowered closed and #4 valve powered open within a #1 PLC pre-programmed time
- #4 valve unpowered closed
- #1 PLC cleaning cycle timer activated
- #8 water valve powered opened
- #1 PLC cleaning cycle timer times out
- #8 water valve closes
- #4 valve is powered to open for a preset time to clear any water in the air/vacuum line
- #4 valve unpowered closed
- SUCTION sequence resumes
  Automatic On-Demand Cleaning will continue to cycle until product coating is no longer detected on the #6 radio frequency product detector rod.
  The scope of the claims should not be limited by the preferred embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole.

Claims

1. A pump system for pumping a fluid product including slurry, sludge or solid laden fluids, comprising:

a pump body (14) for receiving the fluid product, the pump body having a product inlet (12) and a product outlet (13) with respective one-way check valves (15, 15′);

a liquid inlet (8″) for communicating a liquid source with the pump body;

a vacuum inlet (10′) for communicating a vacuum source with the pump body;

a product detector (9) for detecting at least one parameter of the fluid product inside the pump body; and

a control system (1) for controlling operation of the liquid source, the vacuum source and the product detector;

wherein the product detector (9) comprises a radio frequency level detector for detecting a level of the fluid product inside the pump body by emitting radio frequency signals that are received by the control system (1).

2. The pump system of claim 1, wherein each of the one-way check valves (15, 15′) include metal check valves with a knife edge cutting seat configured to cut soft solids so as to ensure sealing when the check valves are closed.

3. The pump system of claim 1, wherein the at least one parameter detected by the product detector (9) includes viscosity or thickness of the fluid product.

4. The pump system of claim 1, wherein the liquid inlet (8″) is in communication with a liquid spray device inside the pump body.

5. The pump system of claim 4, wherein the liquid spray device comprises a water spray ball for cleaning the inside of the pump body or adjusting a thickness level of the fluid product.

6. A method of operating the pump system of claim 1, comprising:

generating a vacuum in the pump body (14) by means of the vacuum inlet (10′) to suction the fluid product into the product inlet (12) and the pump body (14) with the inlet check valve (15) being open and the outlet check valve (15′) being closed;

detecting a predetermined level of the fluid product inside the pump body (14) by means of the product detector (9); and

after said detecting, supplying compressed air to the pump body (14) to discharge the fluid product through the product outlet (13) with the inlet check valve (15) being closed and the outlet check valve (15′) being open.

7. The method of claim 6, comprising:

monitoring a pressure inside the pump body by means of a pressure monitor (6) connected to the control system (1) and in communication with vacuum inlet (10′); and

detecting a predetermined pressure level inside the pump body (14) and repeating said steps of generating a vacuum, detecting the predetermined level and supplying compressed air.

8. The method of claim 6, comprising:

monitoring a pressure inside the pump body by means of a pressure monitor (6) connected to the control system (1) and in communication with the vacuum inlet (10′);

detecting a predetermined pressure level inside the pump body (14); and

after said detecting the predetermined pressure, injecting liquid into the pump body (14) through the liquid inlet (8″) to reduce viscosity or thickness of the fluid product inside the pump body.

9. The method of claim 6, comprising:

detecting product build-up to a metal rod inside the pump body (14) by the product detector (9); and

after said detecting product build-up, injecting liquid into the pump body through the liquid inlet (8″) to clean said metal rod inside the pump body.

10. A pump system for pumping a fluid product including slurry, sludge or solid laden fluids, comprising:

a liquid inlet (8″) for communicating a liquid source with the pump body;

a vacuum inlet (10′) for communicating a vacuum source with the pump body;

wherein the liquid inlet (8″) is in communication with a liquid spray device inside the pump body for adjusting a thickness level of the fluid product.

11. The pump system of claim 10, wherein each of the one-way check valves (15, 15′) include metal check valves with a knife edge cutting seat configured to cut soft solids so as to ensure sealing when the check valves are closed.

12. The pump system of claim 10, wherein the at least one parameter detected by the product detector (9) includes viscosity or thickness of the fluid product.

13. The pump system of claim 10, wherein the product detector (9) comprises a radio frequency level detector for detecting a level of the fluid product inside the pump body by emitting radio frequency signals that are received by the control system (1).

14. The pump system of claim 10, wherein the liquid spray device comprises a water spray ball for cleaning the inside of the pump body or adjusting a thickness level of the fluid product.

15. A method of operating the pump system of claim 10, comprising:

16. The method of claim 15, comprising:

17. The method of claim 15, comprising:

detecting a predetermined pressure level inside the pump body (14); and

18. The method of claim 15, comprising: