CA1219937A - Solenoid-actuated valve unit for discharging condensed liquid from a compressed gas system - Google Patents
Solenoid-actuated valve unit for discharging condensed liquid from a compressed gas systemInfo
- Publication number
- CA1219937A CA1219937A CA000423732A CA423732A CA1219937A CA 1219937 A CA1219937 A CA 1219937A CA 000423732 A CA000423732 A CA 000423732A CA 423732 A CA423732 A CA 423732A CA 1219937 A CA1219937 A CA 1219937A
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- Canada
- Prior art keywords
- solenoid
- valve
- valve unit
- timer circuit
- housing
- Prior art date
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Abstract
ABSTRACT OF THE DISCLOSURE
A solenoid-actuated valve unit for discharging condensed liquid from a compressed gas or air system at predetermined time intervals is provided herein. It includes a liquid discharge valve and a solenoid for operating the same. The function of the solenoid is controlled by an electronic timer circuit, which is arranged within the same housing as the solenoid. Preferably, the solenoid housing comprises a removable cover, and the electronic timer circuit may then be fastened to the inner side surface of the cover. Thus, the present invention provides a single unit by means of which condensed liquid may automatically be discharged from a compressed gas system, e.g., a compressed air system, at predeter-mined time intervals.
A solenoid-actuated valve unit for discharging condensed liquid from a compressed gas or air system at predetermined time intervals is provided herein. It includes a liquid discharge valve and a solenoid for operating the same. The function of the solenoid is controlled by an electronic timer circuit, which is arranged within the same housing as the solenoid. Preferably, the solenoid housing comprises a removable cover, and the electronic timer circuit may then be fastened to the inner side surface of the cover. Thus, the present invention provides a single unit by means of which condensed liquid may automatically be discharged from a compressed gas system, e.g., a compressed air system, at predeter-mined time intervals.
Description
The present invention relates to a solenoid-actuated valve unit for discharging condensed liquid from a compressed gas system at predetermined time intervals.
As an example, in compressed air systems, in which air from the ambient atmosphere containing a percentage of water vapour, is com-pressed, it is normally desired to remove at least part of the water vapour from the compressed air. Therefore, the compressed air may pass a cooling system, in which part of the water vapour is condensed and passed to a liquid drain for intermittently discharging condensed water and pos-sible other liquid substances, such as suspended oil droplets or the like, ~roln the compressed air system. Such drain may be controlled by an auto-matic valve unit as that mentioned above.
It is known to discharge condensed water from a compressed air system at predetermined time intervals by means of a solenoid-actuat-ed valve unit, which is controlled by means of a separate timer unit.
~he timer unit is electrically connected to the solenoid of the valve unit:~ which is adaptecl to open the water discharge valve of the valve unit IQr a short period o~ time at predetermined time intervals. The timer unit comprises a pair of partly overlapping, mutually adjustable ?~ cams which activate a turn on/turn off switch. The length of the time period, in which the water discharge valve is opened, may be adjust-ed by adjusting the mutual position of the partly overlapping cams, while the length of the time intervals between the valve opening periods may be adjusted by changing the rotational speed of the cams. Thus, in the known compressed air systems automatic discharge of condensed water and/or oil involves the use of a solenoid-actuated valve unit and a sep-arate cam-operated timer unit, which is electrically connected to the ~-- 1 - ~ \
solenoid of the valve.
The present invention proposes to provide a single unit by means of which condensed liquid may automatically be discharged from a compressed gas system, e.g., a compressed air system, at predetermined time intervals.
Thus, the present invention provides in one broad aspect thereof a solenoid-actuated valve unit for discharging condensed liquid Erom a compressed gas system at predetermined time intervals, the valve unit comprising: a discharge valve including a valve body; a solenoid 1~ having an armature connected to the valve body for moving the valve body between open and closed positions; an electronic timer circuit for ener-gizing the solenoid for a short time period at predetermined time intervals;
and a housing containing the solenoid as well as the timer circuit.
Even though it is obviously advantageous to arrange the timer and the solenoid within the same housing, this constitutes a striking departure from the prior art~ according to which two separate units inter-connected by electrical cables are used.
}~y another aspect oE this in~ention, an improvement is plo~ided in a solenoid~actuated valve unit for discharging condensed X~ liquid from a compressed gas system at predetermined time intervals and comprising a liquid discharge valve, a solenoid arranged within a housing for mo~ing the valve between open and closed positions, a timer for energizing the solenoid for a short time period at predetermined time intervals, the improvement wherein the timer is an electronic timer cir-cuit which is arranged within the solenoid housing.
By yet another aspect of this invention, a removable cover is provided for a housing for a solenoid-actuated valve unit for dis-g37 charging condensed liquid from a compressed gas system at predetermined time intervals, the unit comprising; a liquid discharge valve; a solenoid arranged within the housing for moving the valve between open and closed positions; an electronic timer circuit, which is arranged within and fastened to the cover and being adapted to energize the solenoid for a short time period at predetermined time intervals.
By one variant of these aspects of the invention, the elec-tronic tirner circuit includes a printed circuit board.
By another variant of these aspects of the invention, the Q solenoid housing includes a removable cover, the timer circuit being fastened to an inner side surface thereof.
By yet another variant of these as?ects of the invention, the timer circuit includes an RC-network.
By still another variant of these aspects of the invention, the RC-network includes a variable resistor, and a rotatable knob for adjustment of the variable resistor arranged on an outer side surface of the cover.
By a further variant of these aspects of the invention, the timer circuit includes an adjustable electronic element for varying the ~ short period in which the solenoid is energized.
By still a further variant of these aspects of the invention, the discharge valve comprises a valve block fastened to the solenoid housing and defining a liquid discharge passage therein, the valve body being arranged within the valve block movable between its closed position, in which the discharge passage is closed, and its open position, in which the discharge passage is open to allow discharge of condensed liquid frorn ~9~37 Lhe compressed gas system.
The electronic timer circuit is preferably of a type requiring a small space only in the common housing. Thus, the electronic timer circuit preferably includes a printed circuit board. The timer circuit may then be accomodated within the housing of a universal or multi-purpose solenoid-operated valve unit. Such universal, generally available, solenoid-actuated valve unit may then rather simply be modified so as to be in accordance with aspects of the present invention, namely_ by accomodating an electronic timer circuit within the existing housing IQ of the solenoid, and by electrically connecting the timer circuit to the solenoid.
In a preferred embodiment of the valve unit according to an aspect of the invention, the solenoid housing includes a removable cover or lid, and the timer circuit is fastened to the inner side thereof.
The timer circuit may then be removed together with the removable cover or lid, which is advantageous in case of replacement or repair of the timer circuit. Furthermore, a conventional, universal solenoid-actuated valve ~Inir comprising a solenoid housing having such a cover or lid may be modified so as to be in accordance with an aspect of the present invention ~Q by replacing the original cover or lid by a corresponding cover or lid prc)vicled with a suitable electronic timer circuit, and by electrically connecting the timer circuit to the solenoid.
The timer circuit may include an RC-network defining the time interval at which the solenoid-operated valve is opened. In order to render possible the carrying out of an adjustment of the time interval, the RC-network may include a variable resistor and a rotatable knob for adjustment of the variable resistor may then be arranged on the outer ~.Z~9~37 side of the lid, whereby the adjustment of the predetermined time interval is highly facilitated.
The timer circuit may also include an adjustable electronic element for varying the short period in which the solenoid is energized so as to open the liquid discharge valve. The variation of this period is less important than the variations of the time intervals between the liquid discharge periods. Therefore, this adjustable electronic element may be less accessible, so that it may be necessary to remove the cover or lid in order to adjust this time period. Thus, the adjustable elec-IQ tronic element may be a trimming potentiometer, a trimming condenser, or a trimming coil, preferably a trimming potentiometer of an RC-network.
The discharge valve body may cooperate with a valve seat formed within a valve housing which may be an integral part of the housing common to the solenoid and the timer circuit. Alternatively, the valve seat may be formed within a separate valve housing or valve block, which is removably fastened to the solenoid housing, whereby the valve housing and the valve body arranged therein may be replaced.
In the accompanying drawings, Fig. 1 is a perspective view of an embodiment of a solenoid-=Q actuated valve unit according to an aspect of the invention, Fig. 2 is a perspective exploded view of the valve unitshown in Fig. 1, Fig. 3 is a perspective view of a preferred embodiment of a part of the solenoid-actuated valve unit according to an aspect of the invention, Fig. 4 is a diagram illustrating an automatic operating system for discharging condensed water from a compressed air system and __ including a valve unit as that shown in Figs. 1 - 3, and Fig. 5 is a diagram illustrating an embodiment of an elec-tronic timer circuit included in the valve unit of Figs. 1 - 3.
Fig. 4 diagrammatically illustrates part of a compressed-air system comprising a compressed-air tank 10 with a discharge conduit 11 for discharging condensed water from the tank 10 to a drain 12. The dis-charge conduit 11 contains a manually operable shut-off valve 13, which is normally closed. The shut-off valve 13 is bypassed by a bypass conduit 14, which also contains a manually operable shut-off valve 15. However, the valve 15 is normally open. A solenoid-operated valve unit 16 con-trolling the bypass conduit 14 is arranged downstream of the shut-off valve 15, and a separator 17 for separating sludge, oxide scales, and other solid matter from the condensed water to be discharged, is inserted in the bypass conduit 14 between the valve 15 and the valve unit 16. The purpose of the separator 17 is to retain solid matter which might cause malfunction of the solenoid-operated valve unit 16.
Figs. 1 and 2 show an embodiment o~ Lhe solenoid-operated valve unit 16 more in detail. The valve unit 16 comprises a solenoid c~Qil 18 having an armature 19, which is connected to a valve body 20, which ~0 may be moved between open and closed positions by means of the solenoid 18. The valve body 20 is mounted within a valve housing or block 21 having a through bore 22 forming part of the bypass conduit 14. The valve body 20 which may, for example, be a so-called puppet valve, cooperates with a valve seat (not shown) in such a manner that the bore 22 is opened and closed, when the valve body 20 is in its open and closed positions, respectively. The solenoid coil 18 and armature 19 are mounted within a 3~
solenoid housing 23. The valve block 21 may, for example, be made from stainless steel, and is fastened to the solenoid housing 23 so that an outer surface of the block 21 is in tight engagement with an adjacent outer surface part 24 of the solenoid housing 23. The so]enoid armature 19 extends through an opening in the surface part 24 into an aligned bore in the valve block 21 extending transversely to the transverse bore 22.
An electrical cable 25 for supplying energiæing electrical current to the solenoid coil 18 extends into the housing through a cable gland 26. At one end the solenoid housing 23 is closed by means of a cover or lid 27, l~ which is removably fastened to the housing 23 by means of screws 28, and a xenling gnsket 29 is arranged between the housing 23 and the cover 27.
WiChin the housing 23, an earthing terminal 38 is arranged. The housing 23 and the cover 27 may, for example, be moulded from a suitable synthetic plastics material, e.g., polyamide.
As far as described up till now the valve unit shown in Figs.
I and 2 is of a generally available type, e.g., one which is marketed by Sperry Vickers Lucifer S.A., Carouge-Geneva, Switzerland. However, nccor~lin~ to aspects of the present invention this generally known valve unit llas been modified by arranging an electronic time circuit for con-~ trolling the function of the solenoid valve 18, 18 within the solenoid housing 23.
In Fig. 3, a preferred embodiment of a removable cover 39for the above described solenoid-actuated valve unit is shown. The e]ectronic timer circuit preferably includes a printed circuit board 33 which is arranged within the cover 39 and fastened thereto by means of screws (not shown). By arranging the electronic timer circuit on a printed circuit board within the removable cover 39, the electronic timer circuit may very easily be removed from the housing, whereby replacement and repair of the timer circuit may be facilitated. In the ernbodiment shown in Fig. 2, the electronic timer circuit included on the printed circuit board 33 is also preferably fastened to the lid or cover 27. The elec-tronic timer circuit furthermore includes a variable element e.g., a resistor, capacitor, or coil, which is adapted to cooperate with a rotat-able knob 31 for adjustment of the time interval at which the solenoid coil 18 should be energized so as to move the valve body 20 to its open 1~ position. The knob 31 is preferably adapted to cooperate with a scale 32 having appropriate scale markings. The electronic timer circuit incluclecl on the printed circuit board 33 is, as best shown in Fig. 2, through conductors 34, 35 connected to a solenoid coil circuit arranged within the housing 23. Apart from the solenoid coil, the above described generally available valve unit also includes a rectifier comprising one or more silicon diodes, an overload protection fuse, and an RC-protection circuit incapsulated within the housing 23.
As is evident from Figs. 2 and 3, some of the components of the ele~ctronic timer circuit are arranged on a thick film substrate 36.
As an example, in compressed air systems, in which air from the ambient atmosphere containing a percentage of water vapour, is com-pressed, it is normally desired to remove at least part of the water vapour from the compressed air. Therefore, the compressed air may pass a cooling system, in which part of the water vapour is condensed and passed to a liquid drain for intermittently discharging condensed water and pos-sible other liquid substances, such as suspended oil droplets or the like, ~roln the compressed air system. Such drain may be controlled by an auto-matic valve unit as that mentioned above.
It is known to discharge condensed water from a compressed air system at predetermined time intervals by means of a solenoid-actuat-ed valve unit, which is controlled by means of a separate timer unit.
~he timer unit is electrically connected to the solenoid of the valve unit:~ which is adaptecl to open the water discharge valve of the valve unit IQr a short period o~ time at predetermined time intervals. The timer unit comprises a pair of partly overlapping, mutually adjustable ?~ cams which activate a turn on/turn off switch. The length of the time period, in which the water discharge valve is opened, may be adjust-ed by adjusting the mutual position of the partly overlapping cams, while the length of the time intervals between the valve opening periods may be adjusted by changing the rotational speed of the cams. Thus, in the known compressed air systems automatic discharge of condensed water and/or oil involves the use of a solenoid-actuated valve unit and a sep-arate cam-operated timer unit, which is electrically connected to the ~-- 1 - ~ \
solenoid of the valve.
The present invention proposes to provide a single unit by means of which condensed liquid may automatically be discharged from a compressed gas system, e.g., a compressed air system, at predetermined time intervals.
Thus, the present invention provides in one broad aspect thereof a solenoid-actuated valve unit for discharging condensed liquid Erom a compressed gas system at predetermined time intervals, the valve unit comprising: a discharge valve including a valve body; a solenoid 1~ having an armature connected to the valve body for moving the valve body between open and closed positions; an electronic timer circuit for ener-gizing the solenoid for a short time period at predetermined time intervals;
and a housing containing the solenoid as well as the timer circuit.
Even though it is obviously advantageous to arrange the timer and the solenoid within the same housing, this constitutes a striking departure from the prior art~ according to which two separate units inter-connected by electrical cables are used.
}~y another aspect oE this in~ention, an improvement is plo~ided in a solenoid~actuated valve unit for discharging condensed X~ liquid from a compressed gas system at predetermined time intervals and comprising a liquid discharge valve, a solenoid arranged within a housing for mo~ing the valve between open and closed positions, a timer for energizing the solenoid for a short time period at predetermined time intervals, the improvement wherein the timer is an electronic timer cir-cuit which is arranged within the solenoid housing.
By yet another aspect of this invention, a removable cover is provided for a housing for a solenoid-actuated valve unit for dis-g37 charging condensed liquid from a compressed gas system at predetermined time intervals, the unit comprising; a liquid discharge valve; a solenoid arranged within the housing for moving the valve between open and closed positions; an electronic timer circuit, which is arranged within and fastened to the cover and being adapted to energize the solenoid for a short time period at predetermined time intervals.
By one variant of these aspects of the invention, the elec-tronic tirner circuit includes a printed circuit board.
By another variant of these aspects of the invention, the Q solenoid housing includes a removable cover, the timer circuit being fastened to an inner side surface thereof.
By yet another variant of these as?ects of the invention, the timer circuit includes an RC-network.
By still another variant of these aspects of the invention, the RC-network includes a variable resistor, and a rotatable knob for adjustment of the variable resistor arranged on an outer side surface of the cover.
By a further variant of these aspects of the invention, the timer circuit includes an adjustable electronic element for varying the ~ short period in which the solenoid is energized.
By still a further variant of these aspects of the invention, the discharge valve comprises a valve block fastened to the solenoid housing and defining a liquid discharge passage therein, the valve body being arranged within the valve block movable between its closed position, in which the discharge passage is closed, and its open position, in which the discharge passage is open to allow discharge of condensed liquid frorn ~9~37 Lhe compressed gas system.
The electronic timer circuit is preferably of a type requiring a small space only in the common housing. Thus, the electronic timer circuit preferably includes a printed circuit board. The timer circuit may then be accomodated within the housing of a universal or multi-purpose solenoid-operated valve unit. Such universal, generally available, solenoid-actuated valve unit may then rather simply be modified so as to be in accordance with aspects of the present invention, namely_ by accomodating an electronic timer circuit within the existing housing IQ of the solenoid, and by electrically connecting the timer circuit to the solenoid.
In a preferred embodiment of the valve unit according to an aspect of the invention, the solenoid housing includes a removable cover or lid, and the timer circuit is fastened to the inner side thereof.
The timer circuit may then be removed together with the removable cover or lid, which is advantageous in case of replacement or repair of the timer circuit. Furthermore, a conventional, universal solenoid-actuated valve ~Inir comprising a solenoid housing having such a cover or lid may be modified so as to be in accordance with an aspect of the present invention ~Q by replacing the original cover or lid by a corresponding cover or lid prc)vicled with a suitable electronic timer circuit, and by electrically connecting the timer circuit to the solenoid.
The timer circuit may include an RC-network defining the time interval at which the solenoid-operated valve is opened. In order to render possible the carrying out of an adjustment of the time interval, the RC-network may include a variable resistor and a rotatable knob for adjustment of the variable resistor may then be arranged on the outer ~.Z~9~37 side of the lid, whereby the adjustment of the predetermined time interval is highly facilitated.
The timer circuit may also include an adjustable electronic element for varying the short period in which the solenoid is energized so as to open the liquid discharge valve. The variation of this period is less important than the variations of the time intervals between the liquid discharge periods. Therefore, this adjustable electronic element may be less accessible, so that it may be necessary to remove the cover or lid in order to adjust this time period. Thus, the adjustable elec-IQ tronic element may be a trimming potentiometer, a trimming condenser, or a trimming coil, preferably a trimming potentiometer of an RC-network.
The discharge valve body may cooperate with a valve seat formed within a valve housing which may be an integral part of the housing common to the solenoid and the timer circuit. Alternatively, the valve seat may be formed within a separate valve housing or valve block, which is removably fastened to the solenoid housing, whereby the valve housing and the valve body arranged therein may be replaced.
In the accompanying drawings, Fig. 1 is a perspective view of an embodiment of a solenoid-=Q actuated valve unit according to an aspect of the invention, Fig. 2 is a perspective exploded view of the valve unitshown in Fig. 1, Fig. 3 is a perspective view of a preferred embodiment of a part of the solenoid-actuated valve unit according to an aspect of the invention, Fig. 4 is a diagram illustrating an automatic operating system for discharging condensed water from a compressed air system and __ including a valve unit as that shown in Figs. 1 - 3, and Fig. 5 is a diagram illustrating an embodiment of an elec-tronic timer circuit included in the valve unit of Figs. 1 - 3.
Fig. 4 diagrammatically illustrates part of a compressed-air system comprising a compressed-air tank 10 with a discharge conduit 11 for discharging condensed water from the tank 10 to a drain 12. The dis-charge conduit 11 contains a manually operable shut-off valve 13, which is normally closed. The shut-off valve 13 is bypassed by a bypass conduit 14, which also contains a manually operable shut-off valve 15. However, the valve 15 is normally open. A solenoid-operated valve unit 16 con-trolling the bypass conduit 14 is arranged downstream of the shut-off valve 15, and a separator 17 for separating sludge, oxide scales, and other solid matter from the condensed water to be discharged, is inserted in the bypass conduit 14 between the valve 15 and the valve unit 16. The purpose of the separator 17 is to retain solid matter which might cause malfunction of the solenoid-operated valve unit 16.
Figs. 1 and 2 show an embodiment o~ Lhe solenoid-operated valve unit 16 more in detail. The valve unit 16 comprises a solenoid c~Qil 18 having an armature 19, which is connected to a valve body 20, which ~0 may be moved between open and closed positions by means of the solenoid 18. The valve body 20 is mounted within a valve housing or block 21 having a through bore 22 forming part of the bypass conduit 14. The valve body 20 which may, for example, be a so-called puppet valve, cooperates with a valve seat (not shown) in such a manner that the bore 22 is opened and closed, when the valve body 20 is in its open and closed positions, respectively. The solenoid coil 18 and armature 19 are mounted within a 3~
solenoid housing 23. The valve block 21 may, for example, be made from stainless steel, and is fastened to the solenoid housing 23 so that an outer surface of the block 21 is in tight engagement with an adjacent outer surface part 24 of the solenoid housing 23. The so]enoid armature 19 extends through an opening in the surface part 24 into an aligned bore in the valve block 21 extending transversely to the transverse bore 22.
An electrical cable 25 for supplying energiæing electrical current to the solenoid coil 18 extends into the housing through a cable gland 26. At one end the solenoid housing 23 is closed by means of a cover or lid 27, l~ which is removably fastened to the housing 23 by means of screws 28, and a xenling gnsket 29 is arranged between the housing 23 and the cover 27.
WiChin the housing 23, an earthing terminal 38 is arranged. The housing 23 and the cover 27 may, for example, be moulded from a suitable synthetic plastics material, e.g., polyamide.
As far as described up till now the valve unit shown in Figs.
I and 2 is of a generally available type, e.g., one which is marketed by Sperry Vickers Lucifer S.A., Carouge-Geneva, Switzerland. However, nccor~lin~ to aspects of the present invention this generally known valve unit llas been modified by arranging an electronic time circuit for con-~ trolling the function of the solenoid valve 18, 18 within the solenoid housing 23.
In Fig. 3, a preferred embodiment of a removable cover 39for the above described solenoid-actuated valve unit is shown. The e]ectronic timer circuit preferably includes a printed circuit board 33 which is arranged within the cover 39 and fastened thereto by means of screws (not shown). By arranging the electronic timer circuit on a printed circuit board within the removable cover 39, the electronic timer circuit may very easily be removed from the housing, whereby replacement and repair of the timer circuit may be facilitated. In the ernbodiment shown in Fig. 2, the electronic timer circuit included on the printed circuit board 33 is also preferably fastened to the lid or cover 27. The elec-tronic timer circuit furthermore includes a variable element e.g., a resistor, capacitor, or coil, which is adapted to cooperate with a rotat-able knob 31 for adjustment of the time interval at which the solenoid coil 18 should be energized so as to move the valve body 20 to its open 1~ position. The knob 31 is preferably adapted to cooperate with a scale 32 having appropriate scale markings. The electronic timer circuit incluclecl on the printed circuit board 33 is, as best shown in Fig. 2, through conductors 34, 35 connected to a solenoid coil circuit arranged within the housing 23. Apart from the solenoid coil, the above described generally available valve unit also includes a rectifier comprising one or more silicon diodes, an overload protection fuse, and an RC-protection circuit incapsulated within the housing 23.
As is evident from Figs. 2 and 3, some of the components of the ele~ctronic timer circuit are arranged on a thick film substrate 36.
2~ In Fig. 5 a block diagram of a preferred embodiment of the electronic circuit of a solenoid-actuated valve unit according to an aspect of the invention is shown. The circuit is AC mains-supplied and basically comprises four parts: a DC-supply 40, an oscillator/timer circuit lC1, a NOR-gate circuit 41, and a thyristor/rectifier unit 42.
The DC-supply 40 comprises a rectifier diode D1 connected in series with two resistors PTC, R7, respectively, connected in parallel, and a Zener-diode D6 connected in parallel with a storage capacitor C4. - -.37 By emp]oying the resistor PTC which is a resistor having a positive tem-perature coefficient, the entire electronic circuit may be directly connected to the AC mains having a voltage in the range of 110 V - 240 V, since the value of the PTC-resistor increasses considerably when e~posed to an increased potential so that the current of the PTC-resistor does not increase in direct proportion to the increase of the voltage. The output from the DC-supply 40 delivered from the capacitor C4 and the Zener-diode D6 is supplied to the oscillator/timer circuit lC1. The cir-cuit lC1, which preferably is a CMOS circuit, is provided with an internal I~ oscillator the frequency of which is determined by means of a fairst RC-n network 43 defining a first time constant. The RC-network 43 includes a resistor R1, a resistor R2, a resistor R3, a capacitor C1, and a potentio-meter P1 which in the above embodiment is connected to the rotatable knob 31 and, thus, serves the purpose of adjustment of the time interval at which the solenoid coil I8 is energized.
The NOR-gate circuit 41 comprises three NOR-gates (lC2,1;
IC2,2; IC2,3), two resistors R8, R9, and an coupling capacitor C2 together with a se~ries connection of a resistor R4 and a second potentiometer P2 consttuting a second RC-network defining a second time constant. This ?~ second time constant is identical to the energizing time interval of the solenoid coil 18. After the timer of the oscillator/timer circuit lC1 has counted a predetermined number of internally generated pulses, the output of the circuit lC1 goes high shifting the output of the circuit 41 from low to high. The output of the circuit 41 remains high until the coupling capacitor C2 of the circuit has been charged through the series connection of the resistor R4 and the potentiometer P2.
The DC-supply 40 comprises a rectifier diode D1 connected in series with two resistors PTC, R7, respectively, connected in parallel, and a Zener-diode D6 connected in parallel with a storage capacitor C4. - -.37 By emp]oying the resistor PTC which is a resistor having a positive tem-perature coefficient, the entire electronic circuit may be directly connected to the AC mains having a voltage in the range of 110 V - 240 V, since the value of the PTC-resistor increasses considerably when e~posed to an increased potential so that the current of the PTC-resistor does not increase in direct proportion to the increase of the voltage. The output from the DC-supply 40 delivered from the capacitor C4 and the Zener-diode D6 is supplied to the oscillator/timer circuit lC1. The cir-cuit lC1, which preferably is a CMOS circuit, is provided with an internal I~ oscillator the frequency of which is determined by means of a fairst RC-n network 43 defining a first time constant. The RC-network 43 includes a resistor R1, a resistor R2, a resistor R3, a capacitor C1, and a potentio-meter P1 which in the above embodiment is connected to the rotatable knob 31 and, thus, serves the purpose of adjustment of the time interval at which the solenoid coil I8 is energized.
The NOR-gate circuit 41 comprises three NOR-gates (lC2,1;
IC2,2; IC2,3), two resistors R8, R9, and an coupling capacitor C2 together with a se~ries connection of a resistor R4 and a second potentiometer P2 consttuting a second RC-network defining a second time constant. This ?~ second time constant is identical to the energizing time interval of the solenoid coil 18. After the timer of the oscillator/timer circuit lC1 has counted a predetermined number of internally generated pulses, the output of the circuit lC1 goes high shifting the output of the circuit 41 from low to high. The output of the circuit 41 remains high until the coupling capacitor C2 of the circuit has been charged through the series connection of the resistor R4 and the potentiometer P2.
3~
The output of the circuit 4] is connected to the thyristor/
rectifier circuit 42. The circuit 42 includes a thyristor T1 and a four diode, full-wave rectifier D2, D3, D4, D5. The gate of the thyristor T1 is through a resistor R5 connected to the output of the circuit 41.
Furtnermore, the gate of the thyristor T1 is through a parallel connection of a resistor R6 and a capacitor C3 connected to the earth of the entire circuit. When the output of the circuit 41 is high, the thyristor T1 is turned on thus p}oviding a current path between the two halves D2, D4 and D3, D5, respectively, of the full-wave rectifier which is connected in series with the solenoid coil 18.
In a plant or system as that shown in Fig. 4, condensed water may be automatically discharged at desired time intervals. Thus, for example, the electronic timer circuit may be set so as to energize the solenoid coil and, consequently, open the water discharge valve for a period of three seconds every thirty minutes. When the valve body 20 is opened, pressurized air from the tank lO may escape through the bypass Goncluit 14, whereby possible condensed water collected in the bypass ~on(lllit. i~ blown out from the conduit into the drain 12.
E~A~IPL.E
~ In an implementation of the circuit shown in Fig. 5, the ent:ire electronic timer circuit was arranged on a single-sided printed ~ircuit board measuring approximately l mm x l mm. Electronic components employed were: lC1 HEF 4541 BT, lC2 IIEF 4001 BT, T1 C 106 DI, D1-D5 lN
4007, D6 BZX 79 C 12 V, R1 12 kQ., R2 1.8 MQ, R3 1.5 MQ
1/4 W 5O, R4 470 kQ 1/4 W 5-0, R5 8 kQ, R6, 1 kQ, R7 68 kQ 1/3 W
5O, RB 5 MQ, R9 500 kQ, R10 24 kQ, P1 lMQ CP 16, P2 1 MQ, C1 33 nF, C2 10 llF 16 V, C3 100 nF 63 V, C4 33 IIF 16 V, and PTC C 885. ---It is understood that various changes of the embodiment described above may be made within the scope of the present invention.
Thus, in Fig. 2, the printed circuit board of the electronic timer circuit may alternatively be fixedly mounted within the housing 23.
1~
The output of the circuit 4] is connected to the thyristor/
rectifier circuit 42. The circuit 42 includes a thyristor T1 and a four diode, full-wave rectifier D2, D3, D4, D5. The gate of the thyristor T1 is through a resistor R5 connected to the output of the circuit 41.
Furtnermore, the gate of the thyristor T1 is through a parallel connection of a resistor R6 and a capacitor C3 connected to the earth of the entire circuit. When the output of the circuit 41 is high, the thyristor T1 is turned on thus p}oviding a current path between the two halves D2, D4 and D3, D5, respectively, of the full-wave rectifier which is connected in series with the solenoid coil 18.
In a plant or system as that shown in Fig. 4, condensed water may be automatically discharged at desired time intervals. Thus, for example, the electronic timer circuit may be set so as to energize the solenoid coil and, consequently, open the water discharge valve for a period of three seconds every thirty minutes. When the valve body 20 is opened, pressurized air from the tank lO may escape through the bypass Goncluit 14, whereby possible condensed water collected in the bypass ~on(lllit. i~ blown out from the conduit into the drain 12.
E~A~IPL.E
~ In an implementation of the circuit shown in Fig. 5, the ent:ire electronic timer circuit was arranged on a single-sided printed ~ircuit board measuring approximately l mm x l mm. Electronic components employed were: lC1 HEF 4541 BT, lC2 IIEF 4001 BT, T1 C 106 DI, D1-D5 lN
4007, D6 BZX 79 C 12 V, R1 12 kQ., R2 1.8 MQ, R3 1.5 MQ
1/4 W 5O, R4 470 kQ 1/4 W 5-0, R5 8 kQ, R6, 1 kQ, R7 68 kQ 1/3 W
5O, RB 5 MQ, R9 500 kQ, R10 24 kQ, P1 lMQ CP 16, P2 1 MQ, C1 33 nF, C2 10 llF 16 V, C3 100 nF 63 V, C4 33 IIF 16 V, and PTC C 885. ---It is understood that various changes of the embodiment described above may be made within the scope of the present invention.
Thus, in Fig. 2, the printed circuit board of the electronic timer circuit may alternatively be fixedly mounted within the housing 23.
1~
Claims (14)
1. A solenoid-actuated valve unit for discharging condensed liquid from a compressed gas system at predetermined time intervals, said valve unit comprising:
a discharge valve including a valve body;
a solenoid having an armature connected to said valve body for moving said valve body between open and closed positions;
an electric timer circuit for energizing said solenoid for a short time period at predetermined time intervals; and a housing containing said solenoid as well as said timer circuit.
a discharge valve including a valve body;
a solenoid having an armature connected to said valve body for moving said valve body between open and closed positions;
an electric timer circuit for energizing said solenoid for a short time period at predetermined time intervals; and a housing containing said solenoid as well as said timer circuit.
2. A valve unit according to claim 1, wherein said electronic timer circuit includes a printed circuit board.
3. A valve unit according to claim 1, wherein said solenoid housing includes a removable cover, said timer circuit being fastened to an inner side surface thereof.
4. A valve unit according to claim 3, wherein said timer circuit includes an RC-network.
5. A valve unit according to claim 4, wherein said RC-net-work includes a variable resistor, and a rotatable knob for adjustment of the variable resistor arranged on an outer side surface of said cover.
6. A valve unit according to claim 3, wherein said timer circuit includes an adjustable electronic element for varying said short period in which said solenoid is energized.
7. A valve unit according to claim 3, wherein said discharge valve comprises a valve block fastened to said solenoid housing and defining a liquid discharge passage therein, said valve body being arranged within said valve block movable between its closed position, in which the discharge passage is closed, and its open position, in which the dis-charge passage is open to allow discharge of condensed liquid from the compressed gas system.
8. In a solenoid-actuated valve unit for discharging con-densed liquid from a compressed gas system at predetermined time intervals and comprising a liquid discharge valve, a solenoid arranged within a housing for moving the valve between open and closed positions, a timer for energizing the solenoid for a short time period at predetermined time intervals, the improvement wherein said timer is an electronic timer cir-cuit which is arranged within said solenoid housing.
9. A valve unit according to claim 8, wherein said elec-tronic timer circuit includes a printed circuit board.
10. A valve unit according to claim 8, wherein said solenoid housing includes a removable cover, the timer circuit being fastened to an inner side surface thereof.
11. A valve unit according to claim 10, wherein said timer circuit includes a variable electronic timer element for varying the said time intervals, and a rotatable knob for adjustment of the variable element arranged on an outer side surface of the cover.
12. A valve unit according to claim 10, wherein said timer circuit includes an adjustable electronic element for varying said short period in which the solenoid is energized.
13. A removable cover for a housing for a solenoid-actuated valve unit for discharging condensed liquid from a compressed gas system at predetermined time intervals, said unit comprising: a liquid discharge valve; a solenoid arranged within said housing for moving the valve between open and closed positions; an electronic timer circuit, which is arranged within and fastened to said cover and being adapted to energize said solenoid for a short time period at predetermined time intervals.
14. A cover according to claim 14, wherein said electronic timer circuit includes a printed circuit board.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000423732A CA1219937A (en) | 1983-03-16 | 1983-03-16 | Solenoid-actuated valve unit for discharging condensed liquid from a compressed gas system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000423732A CA1219937A (en) | 1983-03-16 | 1983-03-16 | Solenoid-actuated valve unit for discharging condensed liquid from a compressed gas system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1219937A true CA1219937A (en) | 1987-03-31 |
Family
ID=4124795
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000423732A Expired CA1219937A (en) | 1983-03-16 | 1983-03-16 | Solenoid-actuated valve unit for discharging condensed liquid from a compressed gas system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1219937A (en) |
-
1983
- 1983-03-16 CA CA000423732A patent/CA1219937A/en not_active Expired
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| MKEX | Expiry |