Apparatus for pumping a powdery or granular material

Apparatus for pumping a powdery or granular material has a first cylinder and a second cylinder parallel to each other and each having a front end and a rear end, a connector box connecting the respective rear ends of the cylinders for placing them in communication, a material inlet at the front end of the first cylinder, a material outlet at the front end of the second cylinder, a first piston in the first cylinder and a first piston rod connected thereto and extending out of the first cylinder, a second piston in the second cylinder and a second piston rod connected thereto and extending out of the cylinder, and a reciprocating drive connected to the piston rods for reciprocating the pistons simultaneously in the same directions within the respective cylinders, the pistons each having openings therethrough and a first one-way valve on the first piston normally closing the opening therein and opening when the first piston is moving in the forward direction and a second one-way valve on the second piston normally closing the opening therein and opening when the second piston is moving in the rearward direction.

This invention relates to an apparatus for pumping a powdery or granular 
material. 
BACKGROUND OF THE INVENTION AND PRIOR ART 
A so-called Kinyon pump or a rotary-type air locker combined with a low- or 
medium-pressure Roots blower is well known as means for pumping a powdery 
or granular material. However such pumps are not widely utilized, because 
the Kinyon pump has the defect that it causes considerable damage to the 
powdery or granular material due to the sealing system thereof, and also 
that it requires a comparatively large amount of power. The rotary air 
locker system has the defects that the mixing ratio (weight ratio of air 
to pumped material) is small, the efficiency is low, air loss is 
inevitable due to the structure of the air locker, it is not possible to 
utilize the rotary-type air locker with all kinds of powdery or granular 
material, the expense of recovering the powdered material at the exit end 
due to the low mixing ratio thereof is high, it is useful only for 
comparatively short distances of transmission, etc. A batch system of 
pumping is also known, such as the Seller-type and Flaxo-type systems, 
both of which are operated by alternately connecting therewith a plurality 
of batch tanks for carrying out a continuous operation, so that economy of 
operation cannot be obtained except in a large scale plant. 
BRIEF SUMMARY OF THE INVENTION 
The present invention provides a novel apparatus for pumping a powdery or 
granular material, wherein the defects of the prior art means for pumping 
such a powdery material are eliminated, the efficiency of the system is 
high, the ratio of mixing is large, continuous operation is feasible 
because it does not use a batch system, it is useful for a larger or for a 
smaller amount of material depending on demand, and pumping can be carried 
out over a long distance. Accordingly, the apparatus of the invention is a 
highly economical means for transportation of any powdery or granular 
material. 
The apparatus provided according to the invention comprises a first 
cylinder and a second cylinder parallel to each other and each having a 
front end and a rear end, a connector box connecting the respective rear 
ends of said cylinders for placing them in communication, a material inlet 
means at the front end of said first cylinder, a material outlet means at 
the front end of said second cylinder, a first piston in said first 
cylinder and a first piston rod connected thereto and extending out of 
said first cylinder, a second piston in said second cylinder and a second 
piston rod connected thereto and extending out of said second cylinder, 
means connected to said piston rods for reciprocating said pistons 
simultaneously in the same directions within the respective cylinders, 
said pistons each having openings therethrough and a first one-way valve 
means on said first piston normally closing the opening therein and 
opening when said first piston is moving in the forward direction and a 
second one-way valve means on said second piston normally closing the 
opening therein and opening when said second piston is moving in the 
rearward direction.

DETAILED DESCRIPTION OF THE INVENTION 
The device according to this invention has parallel first and second 
cylinders 2 and 2' with the rear ends 3 and 3' connected to each other by 
a hollow cylindrical connector box 4. The forward end 5 of the first 
cylinder 2 (the upper cylinder) is connected to a material inlet 6 and the 
forward end 7 of the second cylinder 2' (the lower cylinder) is connected 
through an air flange 38 and a material outlet funnel 8 to a transport 
pipe 9. In the first and second cylinders 2 and 2' are disposed first and 
second pistons 11 and 11' having piston rods 10 and 10' connected 
therewith, respectively, said pistons being adapted to make a similar 
horizontal reciprocation through a stroke l between dead center points A 
and B in accordance with the motion of the piston rods 10 and 10'. 
The piston rods 10 and 10' are connected with each other by means of a 
connector bar 13, to which the respective rear ends 49 and 52 of the 
piston rods are connected, so that both piston rods 10 and 10' move 
through their strokes together between the dead center points A and B. 
Further, the pistons 11 and 11' are provided with a plurality of openings 
15 and 15' (four openings in this embodiment as seen in FIG. 4) through 
which material is propelled and, as seen clearly in FIG. 3, packing rings 
16 and 16' are inserted into the slots in the peripheries of the pistons 
11 and 11' to form tight seals against the inner walls of the cylinders 2 
and 2'. 
In operation, power in the form of rotation of a motor shaft 17 is 
transmitted from shaft 17 through a chain 19 and chain wheels 18 and 21 
carrying the chain 19 to a crank wheel 22 fixed to a shaft 20, a crank arm 
23 pivotally mounted at a point 25 on the periphery of the crank wheel 22 
and to the middle point 24 of the connector bar 13. 
Thus, when the motor shaft 17 rotates at a constant speed, the crank wheel 
22 will rotate to cause the crank arm 23 to reciprocate so that both 
piston rods 10 and 10' will also reciprocate and the first and second 
pistons 11 and 11' will carry out reciprocal motion simultaneously over 
the same stroke l between the points A and B. 
As seen in FIGS. 3 and 4, a flap valve 26 of an elastic material, such as 
rubber, and simply referred to as a valve hereinafter, has a center hole 
27 which is adapted to receive a boss 11a on the piston 11 attached to the 
piston rod 10, and the zone surrounding the center hole 27 is fastened to 
the boss on the rear side of the piston 11 by means of a ring nut 28. 
Further, valve vanes 29 are formed in valve 26 by a plurality (four in the 
illustrated embodiment) of cuts 30 from the periphery towards the center 
hole 27. The tendency of the valve to tear is prevented by holes 31 
provided at the inner ends of the cuts. Each sector of the valve is freely 
flexible, and the cuts 30 are positioned with respect to the openings 15 
in the piston 11 such that each cut 30 is located at the centerline 
between any adjacent two openings 15 and any sector of the valve 26 will 
just close the openings 15 of the piston when in the normal or undistorted 
state. A flap valve 26' is also provided on the piston 11' of the second 
cylinder 2' on the forward side of the piston 11' and a threaded cap 28' 
tightly fastens the flange valve 26' against a boss 11a' on the piston 11' 
attached to the piston rod 10'. Both the piston rods 10 and 10' are 
tubular and have inner spaces 34 and 34' through which compressed air can 
flow. Radial nozzles or holes 35 are provided in the rod 10 to the rear of 
the piston 11 for communicating the tubular space within the piston rod 
with the space within the first cylinder 2. A small forwardly directed 
nozzle or hole 36 is provided in the threaded cap 28' fitted over the 
front end of the second piston rod 10' and a plurality of small nozzles or 
holes 37 which are directed forward at an angle to the axis the piston rod 
10' are also provided in the threaded cap 28'. Between the front end of 
the second cylinder 2' and the material outlet funnel 8 is provided an 
annular hollow air flange 38, the radially inner wall 39 of which has a 
plurality of air flange nozzles 40 therein directed radially inwardly for 
jetting compressed air radially inwards. The compressed air is fed to the 
connector box 4 and flange 38 from an air source 47 through a mechanical 
valve 42 and supply tubes 50 and 53. An inlet hole 41 is provided at a 
suitable point in the connector box 4 (at a bottom point thereof in the 
illustrated example) for admitting the compressed air into the connector 
box 4. The mechanical valve is provided at a suitable position in the 
vicinity of the first and second cylinders for controlling the flow of 
compressed air from the source 47 and switching it either to the inlet 
tube 50 or 53. The mechanical valve 42 is provided with a valve actuator 
43, which is controlled by a cam 45 which is fixed to a cam shaft 44. A 
chain wheel 54 on the cam shaft 44 having the same diameter as that of the 
chain wheel 21 mounted on the shaft 20 is connected by a chain 54a to 
chain wheel 21 so that the cam shaft 44 rotates at the same speed as the 
shaft 20, for controlling the flow of the compressed air in synchronism 
with the reciprocation of the first and second pistons 11 and 11'. The cam 
45 rotates in contact with the valve actuator 43, so that the valve 
actuator 43 is given a reciprocal motion by the cam 45 during rotation of 
the cam, whereby the compressed air supplied from the air source 47 
through a supply inlet 46 in the mechanical valve 42 is switched between 
the outlets C and D of the mechanical valve 42 during each revolution of 
the cam shaft 44. That is to say, when the first and second pistons 11 and 
11' are advancing in the direction of the arrow "a", the air flow is 
switched to the outlet D of the mechanical valve 42 (FIG. 1), and when the 
pistons are moving in the direction of the arrow "a'", the air flow is 
switched to the outlet C thereof (FIG. 2). The outlet C of the mechanical 
valve 42 is connected through a flexible hose 48 to the rear end 49 of the 
first piston rod 10 and the outlet C is also connected through the tube 50 
to the inlet hole in the connector box 4, and the outlet D of the 
mechanical valve 42 is connected through a flexible hose 51 to the rear 
end 52 of the second piston rod 10' and the outlet D is also connected 
through the tube 53 to the air flange 38. When the mechanical valve 42 is 
switched to the outlet C the compressed air is supplied through the hose 
48 and the holes 35 in the piston rod 10, and through the tube 50 and the 
inlet hole 41 into the first cylinder 2 and the connector box 4, and when 
the mechanical valve 42 is switched to the outlet D the compressed air is 
supplied through the hose 51 and the nozzles 36 and 37 at the front end of 
the rod 10', and through the tube 53, the air flange 38 and the air flange 
nozzles 40 into the second cylinder 2', thereby to fluidize the powdery or 
granular material to accelerate the movement thereof towards the outlet 
funnel 8. 
Accordingly, the powdery or granular material is effectively propelled very 
smoothly by the compressed air jetted thereagainst in synchronism with the 
reciprocation of the first and second pistons 11 and 11' so as to increase 
the efficiency of propulsion of the material. 
The operation and effect of the apparatus will now be described in further 
detail. 
When the first piston 11 is driven in a direction to advance toward the 
material inlet 6 the powdery or granular material as indicated by the 
arrow "a", or from the lower dead center point B to the upper dead center 
point A, as indicated at the top of FIG. 1, the flap valve 26 mounted on 
the backside of the first piston 11 has the sectors flexed backward to 
uncover the openings 15 as shown in FIG. 1, so that the material is driven 
through the openings 15 into the first cylinder 2 to the rear of the first 
piston 11. Because at that moment no communication has been provided 
between the compressed air supply inlet 46 and the outlet C of the 
mechanical valve 42, no compressed air is jetted through the nozzle holes 
35 in the first piston rod 10 nor through the inlet hole 41 provided in 
the connector box 4. On the other hand, when the second piston 11' 
advances towards the material outlet funnel 8 in the direction indicated 
by the arrow "a'" simultaneously with the first piston 11, the powdery or 
granular material filling the cylinder space in front of the second piston 
11' is propelled through the material outlet funnel 8 into the transport 
pipe 9, because the flap valve 26' mounted on the front side of the second 
piston 11' is pushed against the front face 33 of the second piston 11' so 
as to be closely contiguous to the face 33, thereby shutting off the inlet 
opening 15' entirely. Because the inner space of the second cylinder 2' is 
expanded in accordance with the above motion, there is produced increased 
efficacy of the transfer of the material from the front side of the first 
piston 11 through the openings 15 into the first cylinder 2. Because the 
compressed air supply inlet 46 and the outlet D of the mechanical valve 42 
are at this time connected as described above, the compressed air from the 
outlet D flows through the hose 51 and space 34' in the second piston rod 
10', and is jetted from the holes 36 and 37 at the front end of the piston 
rod 10' against the powdery or granular material in front of the second 
piston 11', whereby the material in front of the second piston 11' within 
the second cylinder 2' is fluidized and propelled and is accelerated due 
to the combined effect of fluidization and propulsion and is thus 
vigorously transferred through the material outlet funnel 8 to the 
transport pipe 9. The compressed air from the outlet D of the mechanical 
valve 42 flowing through the tube 53 into the air flange 38 and jetted 
through the air flange nozzle 40 against the material causes fluidization 
of the material in front of the second piston 11' and provides a much 
smoother propulsion of the material. 
Because when the pistons 11 and 11' are driven in the direction of the 
arrow "a", the flap valve 26 of the first piston 11 is opened, and the 
valve 26' of the second piston 11' is closed, the space in the first 
cylinder 2, the connector box 4 and the second cylinder 2' is expanded and 
a low pressure is produced therein until the parts reach the positions as 
seen in FIG. 6. Accordingly, the material within the first cylinder 2 in 
front of the first piston 11 flows vigorously through the connector box 4 
into the second cylinder 2'. 
When the first and second pistons 11 and 11' are driven in a direction 
opposite to that described above, or from the upper dead center point A to 
the lower dead center point B in the direction indicated by the arrow 
"a'", the flap valve 26 closes against the rear side 32 of the first 
piston 11 to close the openings 15 in the piston, and the piston pushes 
the material which has been sucked into the first cylinder 2 rearwards 
into the connector box 4 and towards the second cylinder 2'. At the same 
time the space within the first cylinder 2 in front of the first piston 11 
is expanded, creating a reduced pressure tending to draw material through 
the material inlet 6 into the cylinder space in front of the first piston 
11. During the time the first piston 11 is moving through stroke, the 
compressed air supply hole 46 of the mechanical valve 42 is placed in 
communication with the outlet C, so that compressed air from the outlet C 
flows through the hose 48 and through the holes 35 so as to be jetted 
against the material within the connector box 4, whereby the powdery or 
granular material within the first cylinder 2 is fluidized so that the 
flow thereof through the connector box 4 and the second cylinder 2' to the 
space in front of the second piston 11' is accelerated. 
During this time the second piston 11' also moves in the same direction as 
the first piston 11, being connected therewith, and, during the stroke 
towards the connector box 4, the flap valve 26' on the second piston 11' 
opens as shown in FIG. 2, so that the material driven through the first 
cylinder 2 and the connector box 4 into the second cylinder 2' is 
transferred into the cylinder space in front of the second piston 11' 
towards the material outlet funnel 8. During the course of such a 
transfer, it may be advantageous, depending on the properties of the 
powdery or granular material being pumped, to jet compressed air through 
the small inlet hole 41 provided at some suitable position in the 
connector box 4, the timing preferably being synchronized with the jetting 
of air through the holes 35 in the first piston rod 10. At this time no 
air is jetted from the holes 36 and 37 or from the air flange nozzle 40. 
Further, because the flap valve 26 on the first piston 11 is closed during 
this period, counter flow of the material from the second cylinder 2' 
through the connector box 4 and the first cylinder 2 toward the material 
inlet 6 due to any back pressure is completely prevented. 
Thus during the displacement of the first and second pistons 11 and 11' in 
the direction of the arrow "a'", the flap valve 26 on the first piston 11 
is closed and the flap valve 26' on the second piston 11' is open, and the 
space within the first cylinder 2, the connector box 4 and the second 
cylinder 2' is contracted to move the material therein through the piston 
11' into the space in front of piston 11' in second cylinder 2', while the 
space in front of the first piston 11 is expanded to reduce the pressure 
therein so that the material from the material inlet 6 is caused to flow 
smoothly into the first cylinder 2. 
It will be seen that one cycle of the operation as described is 
accomplished by one reciprocal stroke of the pistons, which in turn is 
produced by one revolution of the crank wheel 22, the rate or rotation of 
which may be varied steplessly depending on the amount of material and the 
distance of transportation. The mechanical valve 42 is operated by means 
of the cam 45 on the cam shaft 44 driven synchronously with the crank 
wheel 22 during the reciprocation of the pistons 11 and 11' for jetting 
the streams of the compressed air against the material within the 
cylinders. The space within the first and second cylinders 2 and 2' and 
the connector box 4 is repeatedly contracted and expanded during the 
simultaneous reciprocation of pistons, so that the powdery or granular 
material is sucked through the material inlet 6 and propelled through the 
first and second cylinders and into the material outlet funnel 8 and into 
the transport pipe 9 efficaciously. 
Depending on the properties of the material and the distance of 
transportation, the device according to the present invention may well be 
operated without the jets of compressed air. That is, the powdery or 
granular material may be efficiently pumped without the use of the jets of 
air through the holes 35 in the first piston rod 10, the compressed air 
inlet hole 41 in the connector box 4, the holes 36 and 37 at the forward 
end of the second piston rod 11' and the air flange nozzles 40 in the air 
flange 38. 
There has thus been provided an apparatus which overcomes the deficiencies 
of the prior art systems, has a high efficiency, has a large mixing ratio, 
can operate continuously and with small or large amounts of material. To 
this end, the apparatus has first and second cylinders 2 and 2' disposed 
in parallel, the rear ends thereof being connected by the connector box 4, 
the first cylinder 2 having the material inlet opening 6 at the front end 
5 thereof, the second cylinder 2' having the material outlet funnel 8 at 
the front end 7 thereof, the first and second pistons 11 and 11' having 
piston rods 10 and 10', respectively, and being adapted to simultaneously 
reciprocate together in the first and second cylinders 2 and 2', 
respectively, the pistons having the openings 15 and 15' therethrough and 
the resilient material flap valves 26 and 26', respectively, one being 
adapted to open and the other to close the openings 15 and 15' 
simultaneously and automatically during the reciprocation of the pistons, 
so that when the pistons are driven rearward, the powdery or granular 
material is sucked through the material inlet opening 6 into the first 
cylinder 2 and at the same time the material which has been passed through 
the opening 15 in the first piston 11 into the first cylinder 2 is shifted 
through the connector box 4 and the openings 15' in the second piston 11' 
toward the space within the second cylinder 2' in front of the second 
piston 11', the flap valve 26' on the second piston being open during the 
rearward stroke thereof, and during such a rearward stroke compressed air 
is jetted from the holes 35 in the first piston rod 10 into the first 
cylinder 2 and also into the connector box 4 to cause the material to be 
fluidized to accelerate it in its transfer towards the space in front of 
the second piston 11' of the second cylinder 2', and when pistons are 
driven forward the material which has been sucked into the first cylinder 
2 is shifted through the openings 15 in the piston 11 as the flap valve 26 
opens into the space behind the first piston 11, and the material within 
the second cylinder 2' in front of the piston 11' is shifted towards the 
material outlet funnel 8 so that the space within the two cylinders and 
the connector box 4 is expanded during the simultaneous movement of the 
pistons and the material sucked through the material inlet 6 is eventually 
propelled through the material outlet funnel 8 to the transport pipe 9, 
and compressed air is jetted from the holes 36 and 37 at the front end of 
the piston rod 10' and from the air flange nozzles 40 in the air flange 38 
against the material in front of the piston 11' thus facilitating the 
acceleration of the material being propelled through the material outlet 
funnels to the transport pipe 9. 
This invention is believed to be far superior to known similar methods and 
devices in that two cylinders disposed in parallel are driven by a common 
crank arm, propulsion of powdery or granular material is greatly 
facilitated by the timed jetting of compressed air against the material 
and the system is comparatively simple and very effective and can easily 
be mass produced.