A plug valve adapted to meter precise quantities of material passing therethrough in which a cylindrical valve plug is rotatably mounted in a cylindrically shaped aperture in a valve body. First and second sets of radially extending inlet and outlet passageways are connected to the valve body aperture, with each inlet passageway being radially opposite a corresponding outlet passageway. Two orthogonally oriented, nonintersecting valve ports extend through the valve plug perpendicular to its axis of rotation, the ports being closely spaced from each other along the axis and with the diameter of each valve port being approximately one-half the diameter of the passageways such that one valve port connects one set of inlet and outlet passageways while the orthogonally positioned second port simultaneously connects the second set of inlet and outlet passageways. One inlet passageway connects to a source of material to be metered, and fills one of the valve ports with a precise volume of the material, the associated outlet passageway of that set of passageways being normally closed to prevent the egress of material therefrom. Rotation of the valve plug aligns the filled valve port with the second set of passageways so as to allow the quantity of metered material to flow from the valve. As one valve port is being filled with a metered quantity of material, the second valve port is being emptied of material simultaneously therewith.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates, in general, to a valve for precisely 
metering or intermittently feeding precise quantities of material. More 
particularly, the present invention relates to a metering valve adapted to 
simultaneously carry out two functions within the valve, namely, a first 
function consisting of metering a precise quantity of material into one 
port of the valve, and a second function consisting of dispensing a 
premeasured quantity of material from a second port in the valve. 
2. Discussion of the Prior Art 
Metering valves of this type are utilized, amongst other applications, for 
the intermittent feeding of predetermined quantities or charges of 
material into a chemical stream at a controlled rate which is determined 
by the rotational speed of the valve plug. Valves having this general type 
of construction are known in the art, and usually are of the plug type 
wherein a single orifice of a predetermined size extends through the valve 
plug perpendicular to the axis of rotation of the latter. The valve plug 
is adapted to assume two separate positions, one placing the orifice in 
communication with a source of material which is to be metered, and the 
second placing it in a position to feed the previously metered material 
into a controlled chemical reaction. Valves of this nature have found 
particular utility in polymerization reactors wherein precise quantities 
or charges of a metered material, such as a catalyst, must be directed 
into the chemical reactor, and particularly reactors employed for the 
polymerization of ethylene into polyethylene. These prior art valves 
require a 90.degree. rotational displacement between filling and discharge 
positions, and a rotational movement of 180.degree. for each complete 
operative cycle. 
Solvik et al U.S. Pat. No. 3,227,312 discloses an improvement over that 
type of plug valve. In particular, Solvik et al disclose a plug valve of 
the shot injecting or feeding type, which operates twice as fast as the 
prior type of plug valves, by requiring only a 90.degree. rotation of the 
valve plug for each operative cycle, in contrast with a 180.degree. valve 
plug rotation necessary in the earlier prior art valve technology. Thus, 
in Solvik et al a cylindrical valve plug is mounted for rotation in an 
aperture provided in a valve body. The valve body has first and second 
sets of radially extending inlet and outlet passageways, with the two sets 
being disposed perpendicular relative to each other. Two nonintersecting 
valve ports extend through the valve plug perpendicular to the plug axis 
of rotation. The centers of the inlets and outlets of both valve ports are 
located in the same plane perpendicular to the axis of rotation of the 
valve plug. The passageways do not intersect because each port passageway 
is inclined or sloped away from the other, with one passageway being 
inclined in a first direction along the axis of rotation and the second 
passageway being inclined in the opposite direction along the axis of 
rotation. However, although a metering valve of this type is capable of 
operating at substantially twice the speed of operation of earlier prior 
art metering plug valves, the manufacture of such a valve is relatively 
complicated and expensive. The forming of the above-mentioned ports in the 
valve plug, one of which inclines in a first direction along the axis of 
rotation and the second of which inclines or slopes in an opposite 
direction along the valve plug axis of rotation, results in a valve plug 
configuration which is both difficult and costly to manufacture, thereby 
rendering such a construction both expensive and uneconomic from a 
commercial standpoint. Thus, it becomes desirable to provide a metering 
valve which incorporates the rapid speed of operation inherent in the 
Solvik et al plug valve design, but which eliminates the necessity of 
having a valve configuration which is difficult and expensive to 
manufacture. 
SUMMARY OF THE INVENTION 
Accordingly, in order to overcome or ameliorate the limitations encountered 
in the prior art, the present invention contemplates the provision of an 
improved metering valve, particularly of the shot-feeding type, which has 
a relatively fast rate of operation, and which is designed so as to be 
relatively simple and inexpensive to manufacture. 
Pursuant to a preferred embodiment of the invention, there is disclosed a 
metering valve of the plug valve type wherein a circular recess is formed 
within a valve body about an axis of rotation. At least first and second 
sets of oppositely disposed radially extending inlet and outlet 
passageways are formed in the valve body and communicate with the recess. 
A round or substantially cylindrical valve plug is mounted for rotation in 
the recess, and has formed therein at least two nointersecting 
through-extending valve ports aligned perpendicular to its axis of 
rotation. The valve ports are spaced from each other along the axis of 
rotation, with each valve port being adapted to respectively connect one 
set of radially extending inlet and outlet passageways when the valve plug 
is in a predetermined rotational position. Further, the preferred 
embodiment discloses a metering valve of the type described wherein the 
valve ports are linear bores extending along parallel lines through the 
valve plug. More particularly, the disclosed embodiment discloses a 
metering plug valve in which the inlet and outlet passageways all have 
substantially circular cross-sectional shapes and are disposed with their 
centers in a common plane perpendicular to the valve plug axis of 
rotation. Additionally, the valve ports are substantially circular in 
cross-section, and with the diameters of the valve ports being 
substantially one-half the diameters of the valve passageways. This design 
allows the valve ports to be linear passageways spaced parallel from each 
other along the axis of rotation of the valve and still able to connect 
oppositely disposed radially extending inlet and outlet passageways in 
each of several positions of the plug valve. Furthermore, the preferred 
embodiment of the invention also provides for a plug valve wherein hollow 
cylindrical sleeves or inserts are removably insertable within each of the 
valve ports, to thereby enable sleeves accommodating different volumes of 
material within their confines to be selectively positioned within the 
ports, thereby allowing different quantities or charges of material to be 
metered through the plug valve by merely changing sleeve sizes. 
Accordingly, it is a primary object of the present invention to provide a 
novel metering valve of the shot-feeding type which meters quantities or 
charges of a material at a fairly rapid rate, and which is of simple and 
inexpensive construction.

DETAILED DESCRIPTION OF THE DRAWINGS 
Referring now in detail to the drawings, in FIG. 1 there is illustrated a 
top plane view of a metering plug valve 10 constructed pursuant to the 
teachings of the present invention, and which includes a control shaft 12 
having a square-shaped end portion 14 projecting from the valve to enable 
a valve drive (not shown), usually a pneumatic drive, to rotate the shaft 
12 about a central longitudinal axis of rotation. As shown in FIG. 2, 
shaft 12 includes a relatively narrow cylindrical section 16 which, at the 
end opposite to end 14, extends into a larger diameter cylindrical valve 
plug 18 rotatably mounted in a main valve body 20 of the valve 10. The 
shaft 12 may be formed of steel or other suitable material, and its 
cylindrical surface may be coated with chrome oxide or some other 
equivalent wear resistant and durable material. The valve body 20 may be 
machined from mild steel or other suitable material. The valve body has a 
first large diameter, cylindrically shaped aperture 22 extending into a 
second smaller diameter, cylindrically shaped aperture 24, with an annular 
shoulder 26 or flange being formed at the juncture of the two different 
diameter apertures. First and second valve ports 28 and 30 in valve plug 
18 are closely spaced from each other along the axis of rotation of the 
shaft 12, with the port pair being centrally located along the length of 
the valve plug, each port extending across the full width of the valve 
plug as measured through the axis thereof. Valve port 28 is shown in a 
horizontal operative position in the drawings, whereas valve port 30 is 
illustrated in a vertical position, with the valve ports being arranged 
orthogonal relative to each other. Valve plug 18 is rotatably supported in 
valve body 20 by a cylindrical liner 32 which encompasses the arcuate wall 
of the cylindrical valve plug, being interposed between the plug 18 and 
the cylindrical wall surface of aperture 22, and which extends into axial 
contact with annular shoulder 26 in the valve body. Liner 32 may, 
preferably, be constituted of tungsten carbide or some other suitable hard 
wear-resistant material. As illustrated in FIG. 3, the liner 32 has formed 
in its upper surface a first circular inlet aperture 34 adapted to 
communicate with a first circular outlet aperture 36 located directly 
diametrically therebelow in the bottom surface of the liner, and a second 
circular inlet aperture 38 adapted to communicate with a second circular 
outlet aperture 40 disposed on the diametrically opposite side of the 
liner. These four apertures are, respectively, aligned with the valve body 
passageways comprising a first circular, radially extending inlet 
passageway 42 which (as shown) communicates with inlet aperture 34; a 
first circular, radially extending outlet passageway 44 which communicates 
with outlet aperture 36; a second circular, radially extending inlet 
passageway 46 communicating with inlet aperture 38; and a second circular, 
radially extending outlet passageway 48 communicating with outlet aperture 
40. 
The diameters of valve ports 28 and 30 are each somewhat slightly less than 
one-half the diameter of the inlet and outlet apertures and passageways 
with the arrangement being such that, in the position of the valve shaft 
shown in the drawings, vertically oriented valve port 30 communicates 
between inlet passageway 42 and outlet passageway 44, and horizontally 
oriented valve port 28 extends between inlet passageway 46 and outlet 
passageway 48. When the shaft 12 is rotated through an angle of 
90.degree., each valve port is correspondingly rotated so as to, 
respectively, communicate between the opposite sets of inlet and outlet 
passageways. Thus, in essence, if initially valve port 30 extends between 
passageways 42 and 44, upon rotation of the valve shaft through 90.degree. 
it will then extend between passageways 46 and 48, whereas valve port 28 
initially extends between passageways 46 and 48 and thereafter, upon 
rotation of the valve shaft through 90.degree., extends between 
passageways 42 and 44. Outlet passageway 44, inlet passageway 46, and 
outlet passageway 48 may be, respectively, connected to other equipment 
through the intermediary of coupling blocks 50, 52 and 54, each seated in 
enlarged diameter portions of, respectively, passageways 44, 46 and 48 and 
bearing against internally formed annular shoulders 56. Each coupling 
includes a centrally formed radially extending bore 58, 60 and 62 having 
its exterior end portion provided with a female pipe thread adapted to be 
engaged by a complementary male pipe threaded fitting. Each of the 
coupling blocks may be formed of steel, or similar suitable material, and 
may be secured to the main valve body 20 by a fillet weld surrounding the 
exterior of the coupling body where it joins the main body 20 of the 
valve. The top coupling member 64 is unique because of the particular 
application for which the disclosed plug valve is utilized, and includes a 
flanged connection having connecting bolt holes 66 provided therein for 
bolting the coupling member to another corresponding flanged member of a 
filling arrangement (not shown). Coupling member 64 is connected to the 
main body 20 of the valve by a short length of pipe 68 which extends into 
an enlarged diameter circular aperture in the flange 64. Similarly, in the 
valve body, pipe 68 extends into a larger diameter bore until it abuts a 
shoulder formed where the larger diameter bore joins inlet passageway 42. 
The diameters of the various bores are selected so that the internal 
diameter of the aperture extending from flange 64 down to inlet aperture 
34 is substantially constant. 
The valve is substantially square-shaped and includes a generally 
square-shaped closure plate member 70 which is attached to the valve body 
20 by four radially spaced bolts 72 which extend through bores in the 
closure plate into corresponding interiorly threaded apertures in the 
valve body. The closure plate is sealed against the valve body by an 
O-ring 74 which is positioned within an annular groove 76 formed in the 
closure plate and extending about the aperture 24 in the valve body 20. 
The valve body 20 is closed at its opposite surface by a generally 
square-shaped bonnet 78. An axially extending cylindrically shaped bore 80 
is formed in the bonnet which is slightly larger than the diameter of the 
cylindrical section 16 of the shaft 12 and which accommodates the shaft 
therein. The bonnet 78 is attached to the valve body 20 by four radially 
spaced bolts 82 which extend through four bores formed in the bonnet into 
suitable internally threaded apertures provided in the housing 20, against 
which they may be tightened. Bonnet 78 includes an annular groove 84, 
which extends about aperture 22 in the valve body, and accommodates an 
O-ring 86 to seal the bonnet against the valve body. The face 88 of the 
valve plug is separated from the bonnet 78 by an annular thrust washer 90, 
which may be formed of Teflon or some other suitable low-friction 
material. The shaft member 12 is urged in a rearward direction, to 
properly position the shaft relative to the housing, by an annular seal 
ring 92, which extends around a portion of the bonnet 78 and abuts the 
annular front face 88 of the valve plug. The seal ring is urged against 
the annular front face 88 of the valve plug by a compressed spring 94 
which fits into an annular slot 96 formed in the rear face of the bonnet. 
An O-ring 98 is positioned in an annular groove 100 formed in the bonnet, 
and extends about the bonnet in sealing engagement with the seal ring 92. 
A gland 102 encompasses shaft 12 and has an axially extending cylindrically 
shaped bore 104 formed therein to accommodate the passage therethrough of 
shaft 12. Suitable bolts 106 attach the gland 102 to the bonnet 78. The 
bonnet includes an increased diameter axially extending internal bore 
portion 108 extending about the front section or shaft 12 so as to form an 
annular space therebetween. Packing rings 110 are positioned to fill the 
annular space and are squeezed between a shoulder formed on the gland 102 
and the shaft 12 by a flange 112 formed on the inner face of the gland 
102. Tightening of bolts 106 causes the flange 112 to press the packing 
rings into the annular slot against the shoulder 114 to seal the valve, 
and particularly to seal the lubricants thereof. A suitable lubricating 
bore and thread 116 may be provided in the bonnet 78 for attachment of a 
lubricating fitting (not shown). 
One unique aspect of the plug valve disclosed by the present invention is 
its designed ability to vary the volume metered in the two valve ports 28 
and 30 by enabling the insertion therein of removable and replaceable 
cylindrically shaped hollow sleeves 118 and 120. These sleeves are held in 
place by snap rings, illustrated at 122 in FIG. 2, which are secured in 
place in annular groove formed in the valve ports. With this arrangement, 
there may be supplied a variety of sleeves, each having different internal 
diameters, so that the volume of material charged to each valve port 
decreases as the internal diameter of the sleeve decreases, and 
conversely. The internal diameter of each sleeve may be selected such that 
the volume of material receivable in each valve port assumes a given 
measurement, for instance 10 cc, 20 cc, 30 cc, and so forth. 
Particular sleeves may be removed from or inserted into the valve ports by 
removing the bolts 82 holding the bonnet 78 in place, and removing the 
latter from the valve. Thereafter, the valve plug 18 may be removed from 
the liner and its surrounding valve, and the snap rings 122 removed to 
allow withdrawal of the sleeves therein. Subsequently, new measuring 
sleeves are inserted therein, and replacement effected of the snap rings. 
In some applications of the invention, the bottom coupling block 50 may be 
connected with a purge or sample valve or, alternatively, block 50 may be 
plugged. When it is desired to remove a sample of the material being 
metered, such material drops from the block 50 through a sample valve, 
which also may be of the plug type, and which may be manually operated. 
Alternatively, the sample plug valve may be coupled to automatic actuating 
means providing for the intermittent operation of the purge valve and 
removal of material therefrom. 
Although one embodiment of a shot-feeder valve has been described in 
detail, it will be apparent to one having ordinary skill in the art that 
many alternative embodiments are within the teachings of the present 
invention. For instance, although the disclosed embodiment shows a plug 
valve having two sets of inlet and outlet passageways and a valve plug 
with two orthogonally disposed valve ports therein, it is apparent that a 
valve may be designed with three or more radially spaced sets of inlet and 
outlet passageways and a valve plug with three or more symmetrically 
disposed valve ports therein. In such a valve, the diameter of each of the 
valve ports would be approximately 1/3, 1/4, etc., the diameter of the 
inlet and outlet passageways. Furthermore, although the disclosed 
embodiment of the plug valve shows the valve plug as being cylindrical in 
shape, in alternative constructions the valve plug may assume other shapes 
such as, for example, a truncated conical shape. 
FIG. 4 of the drawings illustrates one application of the metering valve of 
the present invention wherein a polymerization catalyst is being fed into 
a reactor 130 from a reservoir 132 containing a catalyst slurry. Each 
90.degree. rotational operating cycle of the valve plug of valve 10 
introduces a given quantity of catalyst into the reactor. The catalyst 
storage tank or reservoir 132 is padded with a nonreactive hydrocarbon 
reaction medium to prevent introduction of gases into the reactor. A 
pneumatic system 134 is employed to rotate the shaft 12 of the plug valve. 
The polymerization reaction is exothermic, and the reactor 130 is provided 
with a water cooling jacket 136 to cool the reactor. This arrangement 
allows for measurement in the change in temperature of the water passing 
through the heat exchanger water jacket, and the measurement to be 
utilized for automatically controlling the cycle time of the catalyst 
feeder to maintain the desired reaction rate. In the process control 
circuit illustrated in FIG. 4, thermocouples 138 are placed at the inlet 
and outlet connections of water coolant circulating through the water 
jacket heat exchanger 136. The outputs of the thermocouples are directed 
to a potentiometer controller 140 which detects temperature increases or 
decreases from a given level. The output of potentiometer controller 140 
is conveyed pneumatically to a recorder controller 142, which records the 
output, and is then conveyed to an electropneumatic interrupter 144. The 
interrupter 144 converts the pneumatic signal to an electrical signal 
which is conducted to a repeat cycle timer circuit 146 and thence to a 
four-way solenoid controlled valve 148 which controls the fluid pressure 
into the pneumatic valve actuating mechanism, as illustrated 
schematically. In accordance with the system disclosed schematically 
herein, depending upon the reaction rate within the reactor, the cycle 
time of the catalyst feeder is increased or decreased, as required, to 
maintain a desired chemical reaction rate in the reactor. 
FIG. 5 of the drawings illustrates a further system wherein the plug valve 
of the present invention may be utilized, and wherein a material, either 
powdered or liquid, is introduced into a process stream 150. The 
introduced material may be a catalyst, an inhibitor, a moderator, or any 
other material intended to control a specific reaction in the process 
stream or to improve the chemical or physical properties of the final 
product. As shown, an additive storage tank 152 is provided for supplying 
a suitable material to the valve 10, and pneumatic means 154 are provided 
for rotating the shaft 12 of the valve. Flushing is accomplished by a 
liquid or gas introduced at 156, and metered material is delivered to a 
suitable conduit or the like 158 through which the process stream flows. A 
four-way solenoid valve 160, provided for controlling the pneumatic 
metering valve actuation, is controlled by electrical signals received 
from a repeat cycle timer 162. The output signals of this circuit may be 
of a fixed duration, capable of being adjusted manually, or a control 
circuit may be utilized to vary the rate of flow of the material in 
accordance with the rate of flow of the process stream. 
FIG. 6 shows a system in which a sample is intermittently removed for 
analysis from a process of purge stream. A process stream through a 
conduit 170 has a portion of its flow directed through a second conduit 
172 to the plug valve 10, which is actuated by a pneumatic actuating 
mechanism 174. The output of plug valve 10 is directed to a rotameter 176. 
The pneumatic valve actuating mechanism includes a manually operated, or 
timer operated, solenoid four-way valve 178. A suitable inert carrier gas, 
such as helium, is supplied at 180 from a suitable source, and is employed 
to transport samples intermittently and automatically to analyzing 
apparatus (not shown) through the conduit 182. 
Several embodiments of a metering valve and several systems in which a 
metering valve may be utilized have been disclosed. However, it should be 
understood that the teachings of the present invention will suggest other 
embodiments and applications to those skilled in the art, and therefore 
the invention is not considered to be limited to only that which is shown 
in the drawings and described in the specification.