Pumps – One fluid pumped by contact or entrainment with another – Liquid pumped by supplying or exhausting gaseous motive...
Reexamination Certificate
1999-08-09
2001-05-01
Freay, Charles G. (Department: 3746)
Pumps
One fluid pumped by contact or entrainment with another
Liquid pumped by supplying or exhausting gaseous motive...
C417S131000, C417S137000, C417S472000
Reexamination Certificate
active
06224343
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to pumps for groundwater sampling and the like, and, more particularly, to automated air-operated bellows pumps for groundwater sampling and other applications.
BACKGROUND OF THE INVENTION
There does exist many types of submersible pumps for groundwater sampling and other uses.
FIG. 1
shows, generally at
100
, a typical prior-art configuration. Since devices of this kind are inserted down well holes, the unit consists of an outer cylindrical pump body
102
, typically constructed of stainless steel. The body includes a lower inlet end
104
and an upper outlet end
106
. An internal cylindrical bladder
108
, typically constructed of Teflon, partitions the interior of the pump body
102
into a gas-carrying section
110
, and a fluid-carrying section
112
within the bladder
108
.
A tube
114
having, perforations
116
, is generally positioned within the fluid-carrying section
112
, as shown. A lower check valve
120
is provided at the lower inlet end
104
to permit groundwater or like fluids to pass through the lower end
104
and into the tube
114
and fluid-carrying chamber
112
through perforations
116
. The check valve
120
also prevents the fluid from backflowing through the lower inlet
104
. An upper check valve
122
allows fluid from the fluid-carrying chamber
112
to be discharged through the upper end
106
by passing through apertures
116
and into the tube
114
. The upper check valve
122
also prevents the fluid from backflowing down into the pump interior.
Above ground, a controller
130
is provided having a conduit
132
in pneumatic communication with the gas-carrying section
110
within the pump body
102
. The apparatus operates by pressurizing and venting the gas within the chamber
110
, thereby compressing and expanding the bladder
108
, which is quite flexible, thereby forcing fluid within the chamber
112
out the upper end
106
through tube
114
by way of apertures
116
. More particularly, when the pump body is submerged, ground water or other fluid flows into the chamber
112
through tube
114
having apertures
116
through the lower end
104
, bypassing check valve
120
due to natural hydrostatic pressure.
When an actuating gas such as compressed air is driven through conduit
132
and into the gas-carrying section
110
, the bladder
108
is compressed and the lower check valve
120
is forced against the opening
104
, thereby forcing the fluid contained within the fluid-carrying section upwardly and out through the upper opening
106
, displacing check valve
122
in its path. The gas-carrying chamber
110
is then vented at ground level through controller
130
, permitting a fresh charge of ground water to again fill the fluid-carrying chamber
112
and tube
114
through perforations
116
, at which time another cycle may be started by compressing the bladder
108
.
Although a single controller
130
may be configured to control a multiplicity of similar pumps, the timing sequences for each pump must be optimized and stored to ensure the most efficient operation for each sampling station. The timing/cycling means within the controller therefore typically includes a 3-way valve associated with each pump to which it is connected. The 3-way valve is alternatively actuated and de-actuated to produce a pulsating flow to the bladder of each pump, wherein a compressed gas is applied via each conduit
132
, on which the 3-way valve changes state, enabling the gas contained within chamber
110
to be vented to atmosphere. The controller
130
must therefore include electronic, pneumatic or mechanical timing devices associated with each 3-way valve, in each pump, to ensure proper operation thereof.
Although the configuration just described is capable of operating without human intervention after an initial parameter-setting phase, the pump is not really self-cycling, since the controller
130
must be programmed to alternately pressurize and vent the gas-carrying chamber
110
through the single pneumatic path
132
. In addition, the efficiency of the device is dictated by large measure to the depth of the pump, since the hydrostatic pressure at a given level affects the extent to which the fluid-carrying chamber is refilled in accordance with each cycle.
The deeper the pump, the longer must be the pneumatic conduit
132
, requiring a greater degree of pressurization through controller
130
to bring about the most efficient cycling. Even though the control parameters may be entered and altered through the controller
130
, the need still remains for a pump configuration which may be used for groundwater sampling operations which is conducive to further levels of automation. Ideally, such a pump should be self-cycling without the need for sophisticated above-ground control mechanisms.
SUMMARY OF THE INVENTION
This invention resides in an air-operated pump for groundwater sampling and other applications. In contrast to existing configurations, pumps according to the invention feature a collapsible bellows as opposed to the traditional bladder used for fluid collection. The use of a bellows offers a number of advantages over conventional designs, including the potential for truly automatic operation, wherein continuous cycling is maintained without necessarily relying on an above-ground controller to precisely time out the charge and discharge portions of each cycle.
Apparatus according to the invention includes a non-corrosive submersible pump body having a fluid inlet. The preferred embodiment includes an air-supply line and a fluid-discharge line, each coupled to the pump body through a controller disposed at an appropriate above-ground location. A bellows having a closed end and an open end is disposed within the pump body. Although a corrugated-type of bellows is shown and described with reference to the drawings, other types of bellows configurations, including convoluted bellows may alternatively be employed. The bellows is operable between a refill state, wherein fluid is drawn into the pump body through the fluid inlet, and a discharge state wherein fluid is forced out of the pump body through the discharge line. Means disposed within the pump body govern the air received through the air-supply line, thereby at least semi-automatically cycling the bellows between the refill and discharge states.
The bellows may be compressed during the refill state and expanded during the discharge state, or expanded during the refill state and compressed during the discharge state. The open end of the bellows may be oriented upwardly or downwardly when the pump is submersed, though the former is preferred since gas trapped in the bellows may naturally escape upwardly and out of the pump body.
To assist in cycling, a pump according to the invention may further include one or more magnets for latching the bellows in the refill or discharge state. As such, the means for governing the air received through the air-supply line may include an electrical sensor such as a reed switch for detecting whether or not the bellows is latched. As an alternative, the means for governing the air received through the air-supply line may include a valve in the air-supply line which is mechanically coupled to the bellows. A separate exhaust line may also be provided to expel air received through the air-supply line, in which case the means for governing the air received through the air-supply line also preferably governs the air expelled through the exhaust line.
REFERENCES:
patent: 2807215 (1957-09-01), Hawxhurst
patent: 3749526 (1973-07-01), Ferrentino
patent: 3938910 (1976-02-01), Douglas
patent: 4104005 (1978-08-01), Poirier
patent: 4257751 (1981-03-01), Kofahl
patent: 4295801 (1981-10-01), Bennett
patent: 4438654 (1984-03-01), Torstensson
patent: 4489779 (1984-12-01), Dickinson et al.
patent: 4585060 (1986-04-01), Bernardin et al.
patent: 4727936 (1988-03-01), Mioduszewski et al.
patent: 4749337 (1988-06-01), Dickinson et al.
patent: 4807707 (1989-02-01), Handley et al.
patent: 4822257 (1989-04-01)
Freay Charles G.
Gifford Krass Groh Sprinkle Anderson & Citkowski PC
Tyler Cheryl J.
LandOfFree
Automated, air-operated bellows pumps for groundwater... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Automated, air-operated bellows pumps for groundwater..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Automated, air-operated bellows pumps for groundwater... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2525045