GB2377684A - Pneumatic conveyor, with bypass line and pressure modulating valve - Google Patents
Pneumatic conveyor, with bypass line and pressure modulating valve Download PDFInfo
- Publication number
- GB2377684A GB2377684A GB0214463A GB0214463A GB2377684A GB 2377684 A GB2377684 A GB 2377684A GB 0214463 A GB0214463 A GB 0214463A GB 0214463 A GB0214463 A GB 0214463A GB 2377684 A GB2377684 A GB 2377684A
- Authority
- GB
- United Kingdom
- Prior art keywords
- pressure
- modulating valve
- line
- product
- valve means
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
- B65G53/00—Conveying materials in bulk through troughs, pipes or tubes by floating the materials or by flow of gas, liquid or foam
- B65G53/34—Details
- B65G53/66—Use of indicator or control devices, e.g. for controlling gas pressure, for controlling proportions of material and gas, for indicating or preventing jamming of material
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Air Transport Of Granular Materials (AREA)
Abstract
A pneumatic conveyor comprises a pressured fluid supply line 13a which splits into a product vessel supply line 18 to, and a bypass line 19 around, a product vessel 10 from which exits a product conveying line 14. A modulating valve 21 is responsive to back pressure to vary the supply of pressurised fluid from the fluid pressure line 13a. Also disclosed is a method of using the aforementioned apparatus comprising varying the supply of fluid under pressure to the product vessel 10 in response to back pressure in either the product vessel supply line 18 or the bypass line 19. This might be achieved by the positioning of the modulating valve 21 in either the product vessel supply line 18 or the bypass line 19 as per modulating valve 21' in fig.2. The modulating valve 21 may be a self actuating valve responsive to back pressure. The system may further include a number of other adjustment and regulating valves and a control panel 29. The system may permit the pressure balancing of the pneumatic conveyor as a whole, and may allow it to deal with variations in feed characteristics of differing particulate material products to be stored in the product vessel 10, and transported or dispensed by the system.
Description
<Desc/Clms Page number 1>
PATENTS ACT 1977 A10200GB-JNL/RAL/jm
Title: Pneumatic Transport System
Description of Invention
This invention relates a pneumatic transport system.
Systems for the pneumatic transport of products such as powders or other dry materials are well known. In such systems, a product which is to be transported is supplied to a product vessel. A fluid under pressure, for example compressed air, is supplied to the product vessel from a supply of fluid under pressure by a fluid pressure supply line to entrain the product and convey the product from the product vessel along a conveying line to a desired destination.
Generally the fluid under pressure comprises air, and the following description will refer to air, but it will be apparent that any appropriate fluid, that is liquid or gas may be used depending on the nature of the product to be transported.
Such transport may take place in several modes. In a particular mode, referred to as"dense phase transport", the product is transferred at relatively low speed with a high solid loading ratio in the mixture of air and product.
The conveying line is also connected to the supply of air under pressure via a bypass line, bypassing the product vessel. The transfer rate in the conveying line is controlled by varying the relative distribution of air supplied to the product vessel and supplied directly to the conveying line via the bypass line. Valves are conventionally located in the air pressure supply line and in the bypass line, and the relative distribution of air under pressure supplied to the conveying line and the product vessel is set by manually controlling the valves.
The valves are usually set during commissioning of the system.
Such a system is however sensitive to variations in the characteristics of the conveyed product. For example, where the settings are optimised for a particular product, they will be less than optimal for different products having different characteristics. This is particularly the case where a product consists
<Desc/Clms Page number 2>
of a mixture of different ingredients, for example a sand and cement mix where the characteristic of a mixture will vary during transport depending on the ratio of sand and cement at a given moment in the course of transport. Equally, where the system is used to transport product over varying distances, the system must in general be optimised for transporting the product over the longest distance, and so will be sub-optimal when transporting product to nearer destinations.
An object of the invention is to provide a new or improved pneumatic transport system.
According to a first aspect of the invention, we provide a pneumatic transport system comprising a product vessel, a conveying line to receive product from the product vessel, a fluid pressure supply line, a product vessel supply line connected between the fluid pressure supply line and the product vessel, a bypass line connected between the fluid pressure supply line and the conveying line, and a modulating valve means, the modulating valve means being responsive to back pressure at the modulating valve means to vary the supply of pressurised fluid from the fluid pressure supply line to the product vessel.
The modulating valve means may be responsive to back pressure at the modulating valve means to vary the relative distribution of air under pressure supplied to the product vessel and through the bypass line to the conveying line.
According to a first alternative, the modulating valve means may be provided in the product vessel supply line.
An adjustable valve maybe provided in the bypass line
The modulating valve means may comprise a self-acting valve responsive to back pressure at the modulating valve means to close at a selected pressure.
According to a second alternative the modulating valve means may be provided in the bypass line.
<Desc/Clms Page number 3>
An adjustable valve may be provided in the product vessel supply line.
The modulating valve means may comprise a self-acting valve responsive to back pressure at the modulating valve means to open at a selected pressure.
In both alternatives, the selected pressure may be set by supplying a control pressure to the modulating valve means.
The control pressure may be varied using a pilot valve.
The modulating valve means may alternatively comprise a valve comprising a biased closure means.
The fluid under pressure may comprise air.
According to a second aspect of the invention, we provide a method of controlling a pneumatic transport system wherein a method of controlling a pneumatic transport system comprising supplying fluid under pressure from a fluid pressure supply line via a product vessel supply line to a product vessel for conveying product in a conveying line, and supplying fluid under pressure to a bypass line connected between the first pressure supply line and the conveying line, comprising the step of varying the supply of fluid under pressure to the product vessel in response to back pressure in the product vessel supply line or the bypass line.
The method may comprise the step of varying the relative distribution of fluid under pressure in the vessel supply line and the bypass line in response to said back pressure.
The method may comprise the step of closing the product vessel supply line when the back pressure exceeds a selected pressure.
The selected pressure may be controlled by supplying a control pressure to a modulating valve.
The selected pressure may be controlled by supplying a control pressure to a modulating valve.
<Desc/Clms Page number 4>
The fluid under pressure may comprise air.
It has thus been found that the pneumatic transport of material may be either improved or optimised by providing a modulating valve responsive to back pressure to control the supply of air under pressure to the product vessel.
The invention will now be described by way of example only with reference to the accompanying drawings, wherein:
Figure 1 is a diagrammatic view of a part of a pneumatic transport system embodying the present invention,
Figure 2 is a diagrammatic view of a part of a further pneumatic transport system embodying the present invention,
Figure 3 is a side view of part of a pneumatic transport system according to the present invention,
Figure 4 is a section on line 4-4 of Figure 3, and
Figure 5 is a side view of Figure 4.
Referring now to Figures 1, and 3 to 5, a product vessel of conventional type is shown at 10, provided with an inclined bed loua, which may be a porous membrane, for example. The product vessel 10 is supplied with a product to be transported to a product inlet 11, controlled by a normally closed product control valve 12. Air under pressure is supplied from an air supply 13, and air supply line 13a to the product vessel 10. Product entrained in the flow of air is transported from the product vessel 10 in a conveying line 14 to a desired destination.
The air supply line 13a is connected via an isolation valve 15. ê :, strainer 15b, regulator 16 and orifice plate part 17 to a product vessel supply line 18 and a bypass line 19. Provided in the vessel line 18 are a first, normally open, control valve 20, a modulating valve means 21 and a one way valve 22. Located in the bypass line 19 are a second, normally open, control valve 23, a manually operable valve 24, and a one way valve 25. The product vessel 10 is connected to the conveying line 14 by a third, normally closed, control valve
<Desc/Clms Page number 5>
26. The conveying line 14 is further connected to the product vessel via line 27 and a fourth, normally open control valve 28. The manually adjustable valve
24 may be set to adjust the desired relative distribution of air in the product vessel supply line 18 and bypass line 19 in the condition when the modulating valve means 21 is open to optimise operation of the conveying system depending on the product to be transported and other system requirements. In particular, it is desirable to"balance"the resistance in the system caused by the bed lOa of the pressure vessel 10 by adjusting the manually adjustable valve means 24.
The system further comprises a control panel 29. The control panel is supplied with a pilot valve 30 connected via line 31 to the air supply line 13 ! ! and via line 32 to the modulating valve 21. The control panel 29 is provided with a pressure gauge 33 and switch 34 connected to the line 31. A further gauge 35 and switches 36a, 36b are connected via line 37 to the product vessel
10.
The modulating valve means 21 comprises a self-acting valve of conventional type which is responsive to back pressure downstream of the modulating valve means 21 to close at a selected pressure.
The selected pressure at which the modulating valve means 21 closes in the preferred example, as shown in Figure 1, is varied by adjusting the control pressure supplied on line 32 via the pilot valve 30. The selected pressure may alternatively may be selected by, for example, providing a modulating valve means 21 comprising a biased closing means such as a spring acting on a closure element to close the modulating valve means 21 at a selected pressure at an outlet of the valve.
In normal operation, air under pressure is supplied from the air pressure supply 13 to the product vessel 10 and the conveying line 14, the relative supply of air being set by the modulating valve means 21 and manually adjustable valve 24. Entrained product from the pressure vessel 10 is carried via the
<Desc/Clms Page number 6>
conveying line 14. The quantity of product supplied from the product vessel 10 to the conveying line 14 depends on the pressure of the air supply to the product vessel 10 from the product vessel supply line 18. The greater the quantity of product entrained in the air flow in the conveying line 14, the greater the back pressure in the conveying line 14, product vessel 10 and product vessel supply line 18. The pilot valve 30 is adjusted to set the modulating valve means 21 to be responsive to a selected pressure.
When the back pressure on the modulating valve means 21 exceeds the selected pressure set by the pilot valve 30, the valve 21 closes, such that air under pressure is diverted via the bypass line 19 to the conveying line 14. As the back pressure in the conveying line 14 and hence in the product vessel supply line 18 is dependent on how much of the product is being carried in the conveying line 14, the reduction of pressure supplied via the product vessel supply line 18 to the product vessel 10 reduces the amount of product being carried to the conveying line 14 and hence reduces the back pressure. When the back pressure in the conveying line 14 and hence at the modulating valve means 21 falls below the selected pressure, the modulating valve means 21 then opens, increasing the pressure of the air supplied on line product vessel supply line 18 to the product vessel 10 relative to the pressure supplied via the bypass line 19. This increases the rate of supply of the product from the vessel 10 to the conveying line 14 and hence the rate of supply in the conveying line 14. As the rate of product supply in the conveying line 14 increases, the back pressure will increase accordingly until the back pressure at the modulating valve means 21 reaches the selected pressure and the modulating valve means 21 again closes.
The line 27 is provided to vent air which is displaced from the vessel 10 during filing of the vessel 10 with product.
By this simple feedback method the rate of supply of product in the convoying line can be maintained at a desired level. The pneumatic transport
<Desc/Clms Page number 7>
system according to the present invention thus provides a simple and efficient system of optimising the supply of product using a pneumatic transport system.
Referring to the embodiment of Figure 2, a pneumatic transport system is shown which is similar to that of Figure 1 but wherein the modulating valve is located in the bypass line 19. In the following description elements which are the same as those of Figure 1 have the same reference numerals and reference numerals indicating elements that have changed are indicated by a prime sign. In the embodiment of Figure 2 a modulating valve means 21'is provided in the bypass line 19, connected to a pilot valve 30 via line 32'. The modulating valve means in this example comprises a self-acting valve of conventional type which is responsive to backpressure downstream of the modulating value means 21'to open at a selected pressure. The selected pressure may be varied by adjusting the control pressure supplied on line 32' via the pilot valve 30. Alternatively, the selected pressure may be selected by providing a modulating valve means 21'comprising a biased operating means such as a spring acting on a closure element to open the modulating valve means 21'in response to a selected pressure at an outlet of the valve.
As in the embodiment of Figure 1, in normal operation air under pressure is supplied from the air pressure supply 13 to the product vessel supply line 18 and the bypass line 19. In operation, product from the pressure vessel 10 is carried via the conveying line 14. The greater the quantity of product entrained in the air flow in the conveyor line 14, the greater the back pressure in the bypass line 19. When the back pressure on the modulating valve means 21' exceeds a selected pressure set by the pilot valve 30, the modulating valve means 21'opens such that more air under pressure passes through the bypass line 19 to the conveying line 14. As in the embodiment of Figure 1, the air pressure supplied via the product vessel supply line 18 to the product vessel 10 falls reducing the amount of product being carried to the conveying line 14 and
<Desc/Clms Page number 8>
reduces the back pressure in the bypass line 19. When the back pressure in the bypass line 19 and hence at the modulating valve means 21'falls below the selected pressure, the modulating valve means 21'then closes, restricting the proportion of the air under pressure passing through the bypass line 19 and increasing the proportion passing to the product vessel 10 along product vessel supply line 18. The relative proportion of air under pressure passing along the bypass line 19 and product vessel supply line 18 is thus varied in accordance with supply of product in the conveyor line 14. In like manner to the embodiment of Figure 1, a manually adjustable valve 24'is provided in the product vessel supply line 18.
Whether the system comprises a modulating valve means 21 located in the pressure vessel supply line 18 or a modulating valve means 21'located in the bypass line 10 depends on such factors as the material which the system is intended to convey, the responsiveness required of the valve means and potential safety consideration. For example, where the product is relatively easy to convey, such as a fine powder, most of the air under pressure will pass through the pressure vessel 10 and it is desirable that the modulating valve means 21'is located in the bypass line 19. In this way, the supply of the air to the pressure vessel can be modulated by making relatively small changes to the valve 21'located in the bypass line 19. Similarly, where a product is relatively difficult to convey or a relatively slow supply of product is required, a relatively small proportion of the fluid under pressure will be supplied to the pressure vessel 10 and it is desirable to provide the valve in the pressure vessel supply line 18. Locating the modulating valve means 21 in the pressure vessel supply line 18 also provides a faster change in the pressure supply to the product vessel 10 in response to a change in back pressure at the valve 21.
A further reason for providing the modulating valve means 21 in the product vessel supply line 18 when the product is difficult to move arises from
<Desc/Clms Page number 9>
the need to"balance"the resistance in each part of the system 10 as discussed hereinbefore. When the product is difficult to move, there will be a relatively high resistance in the product vessel 10 and thus the manually adjustable valve 24 in the bypass line 19 would be almost closed. In the event of failure, conventionally the route to the pressure vessel 10 will be closed, sending all the air through the bypass line 19. In these circumstances, the fluid pressure will be attempted to be routed through an almost closed valve which is clearly undesirable.
Although the valves 24,24'are referred to as being manually adjustable, it will be apparent that they may be adjusted by any suitable means whether mechanical or electrical or otherwise as desired.
Although the present invention refers specifically to air, it will be apparent that the invention may be used with any suitable pressurised fluid transport system as appropriate.
In the foregoing description, references to the modulating valve means 21, 21'opening or closing is intended refer to both the value means moving to a fully open or fully closed configuration as may be, and to the valve means partially opening or closing to a more open or more closed configuration in response to changes in the back pressure as required.
In the present specification"comprise"means"includes or consists of and"comprising"means"including or consisting of.
The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.
Claims (20)
1. A pneumatic transport system comprising; a product vessel, a conveying line to receive product from the product vessel, a fluid pressure supply line, a product vessel supply line connected between the fluid pressure supply line and the product vessel, a bypass line connected between the fluid pressure supply line and the conveying line, and a modulating valve means, the modulating valve means being responsive to back pressure at the modulating valve means to vary the supply of pressurised fluid from the fluid pressure supply line to the product vessel.
2. A pneumatic transport system according to claim 1 wherein the modulating valve means is responsive to back pressure at the modulating valve means to vary the relative distribution of fluid under pressure supplied to the pressure vessel and through the bypass line to the conveying line.
3. A pneumatic transport system according to claim 1 or claim 2 wherein the modulating valve means is provided in the product vessel supply line.
4. A pneumatic transport system according to claim 3 wherein an adjustable valve is provided in the bypass line.
5 A pneumatic transport system according to claim 3 or claim 4 wherein the modulating valve means comprises a self-acting value responsive to back pressure at the modulating valve means to close at a selected pressure.
<Desc/Clms Page number 11>
6. A pneumatic transport system according to claim 1 or claim 2 wherein the modulating valve means is provided in the bypass line.
7. A pneumatic transport system according to claim 6 wherein an adjustable valve is provided in the product vessel supply line.
8. A pneumatic transport system according to claim 6 or claim 7 wherein the modulating valve means comprises a self-acting valve responsive to back pressure at the modulating valve means to open at a selected pressure.
9. A pneumatic transport system according to claim 5 or claim 8 wherein the selected pressure is set by supplying a control pressure to the modulating valve means.
10. A pneumatic transport system according to claim 9 wherein the control pressure is varied using a pilot valve.
11. A pneumatic transport system according to claim 5 or claim 8 wherein the modulating valve means comprises a valve comprising a biased closure means.
12. A pneumatic transport system according to any one of the preceding claims wherein the fluid under pressure comprises air.
13. A pneumatic transport system substantially as described herein and/or with reference to the accompanying drawings.
<Desc/Clms Page number 12>
14. A method of controlling a pneumatic transport system comprising supplying fluid under pressure from a fluid pressure supply line via a product vessel supply line to a product vessel for conveying product in a conveying line, and supplying fluid under pressure to a bypass line connected between the first pressure supply line and the conveying line, comprising the step of varying the supply of fluid under pressure to the product vessel in response to back pressure in the product vessel supply line or the bypass line.
15. A method according to claim 14 comprising the step of varying the relative distribution of fluid pressure in the vessel supply line and the bypass line in response to said back pressure.
16. A method according to claim 14 or claim 15 comprising the step of closing the product vessel supply line or opening the bypass line when the back pressure exceeds a selected pressure.
17. A method according to claim 16 comprising the step of controlling the selected pressure by supplying a control pressure to a modulating valve.
18. A method according to any one of claims 14 to 17 wherein the fluid under pressure comprises air.
19. A method as substantially as described herein with reference to the accompanying drawings.
20. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0115427A GB0115427D0 (en) | 2001-06-23 | 2001-06-23 | Pneumatic transport system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB0214463D0 GB0214463D0 (en) | 2002-07-31 |
| GB2377684A true GB2377684A (en) | 2003-01-22 |
Family
ID=9917252
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0115427A Ceased GB0115427D0 (en) | 2001-06-23 | 2001-06-23 | Pneumatic transport system |
| GB0214463A Withdrawn GB2377684A (en) | 2001-06-23 | 2002-06-24 | Pneumatic conveyor, with bypass line and pressure modulating valve |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB0115427A Ceased GB0115427D0 (en) | 2001-06-23 | 2001-06-23 | Pneumatic transport system |
Country Status (1)
| Country | Link |
|---|---|
| GB (2) | GB0115427D0 (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0589053A1 (en) * | 1992-04-13 | 1994-03-30 | Mitsubishi Materials Corporation | Method and apparatus for feeding ultra-fine powder in constant-quantity batch |
| DE19539610A1 (en) * | 1995-10-25 | 1997-04-30 | Maxit Baustoffwerke Gmbh | Automatic delivery control for pneumatic cleaning machine |
| DE19604578A1 (en) * | 1996-02-08 | 1997-08-14 | Pft Gmbh | Dry mortar mix delivery system for building or construction site |
| JPH11130257A (en) * | 1997-10-31 | 1999-05-18 | Akatake Engineering Kk | Pneumatic carrier device for powder and grain |
-
2001
- 2001-06-23 GB GB0115427A patent/GB0115427D0/en not_active Ceased
-
2002
- 2002-06-24 GB GB0214463A patent/GB2377684A/en not_active Withdrawn
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0589053A1 (en) * | 1992-04-13 | 1994-03-30 | Mitsubishi Materials Corporation | Method and apparatus for feeding ultra-fine powder in constant-quantity batch |
| DE19539610A1 (en) * | 1995-10-25 | 1997-04-30 | Maxit Baustoffwerke Gmbh | Automatic delivery control for pneumatic cleaning machine |
| DE19604578A1 (en) * | 1996-02-08 | 1997-08-14 | Pft Gmbh | Dry mortar mix delivery system for building or construction site |
| JPH11130257A (en) * | 1997-10-31 | 1999-05-18 | Akatake Engineering Kk | Pneumatic carrier device for powder and grain |
Non-Patent Citations (3)
| Title |
|---|
| WPI A.A.N: 1997-246270 [23] & DE 19539610 A * |
| WPI A.A.N: 1997-403641 [38] & DE 19604578 A * |
| WPI A.A.N: 1999-352424 [30] & JP 11 130 257 A * |
Also Published As
| Publication number | Publication date |
|---|---|
| GB0214463D0 (en) | 2002-07-31 |
| GB0115427D0 (en) | 2001-08-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US3987622A (en) | Load controlled fluid system having parallel work elements | |
| US4662799A (en) | Apparatus and process for pneumatically conveying particulate material | |
| EP0864369A3 (en) | Control system for a mobile material distribution device | |
| US5813801A (en) | Dense phase particulate conveying system and method with continuous air leakage management | |
| US4482275A (en) | Method and apparatus for distributing powdered particles | |
| US3403941A (en) | Pneumatic conveying system | |
| US6619027B1 (en) | Gas turbine having rotor overspeed and overboost protection | |
| US4861200A (en) | Apparatus for pneumatically conveying bulk material | |
| US5337788A (en) | Pneumatic valve with slow start and quick exhaust | |
| GB2176245A (en) | Gas turbine fuel control | |
| US5855456A (en) | Apparatus and method for unblocking conveying pipe | |
| CN110230702A (en) | For reducing the solenoid operated valve of excessive pipeline pressure in fuid distribution system | |
| JPH01250602A (en) | Hydraulic type changeover device | |
| US3104030A (en) | Pneumatic discharge systems | |
| US4665939A (en) | Priority control for hydraulic consumers | |
| US3574474A (en) | Method of and apparatus for controlling the operation of gas compression apparatus | |
| GB2377684A (en) | Pneumatic conveyor, with bypass line and pressure modulating valve | |
| US3556126A (en) | Pipeline valve control system | |
| US4625749A (en) | Pressure supply device for a hydraulic system | |
| JP4330686B2 (en) | Pressure regulator | |
| EP0046287A1 (en) | Fluid regulator | |
| EP1047867B1 (en) | Force balanced proportional bypass valve | |
| JPH06278868A (en) | Conveying pressure adjusting device of high pressure powder conveying system | |
| JPS61156414A (en) | Apparatus for controlling flow rate of fluid | |
| US2102330A (en) | Conveying apparatus |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |