Hand
Operated Vacuum Packing System for Seed Storage
By Allen Dong and Roger J. Edberg, I-Tech, P O Box 413 Veneta, Oregon 97487,
USA
This invention was declared public domain on November 29, 1989, a gift to humanity
.
A hand operated vacuum packing system (Figure 1) was developed to facilitate the storage of dry seeds. The system provides a means to seal containers with reduced oxygen content. A sealed container prevents rehydration of seeds, thus extends their viability. The reduced oxygen content suffocates adult insects that are stored with the seeds, and also extends the viability of the seeds by slowing down the seed respiration rate. This system can be used to vacuum pack dry food. Moist food, however, needs to be properly sterilized before it is vacuum packed.
Materials:
* A bicycle tire pump, with the pump plunger seal or cup in reverse
(A), and used as a vacuum pump.
* A tire inner tube stem valve (B) is used as a check valve to prevent
back flow of air into the vacuum chamber.
* A lid for the vacuum chamber. The lid is made from a rubber stopper(C),
a thin sheet metal or plywood (D), and a sheet of rubber made from a tire
inner tube (E). The sheet of rubber (E) should be slightly larger than
the lid (D) and serves as a lid gasket.
* A glass jar (F) with resealable lid is used as vacuum-sealed container.
* A large food can (G) is used as a vacuum chamber. The can should be
wider and taller than the largest glass jar (F).
Figure 1. The vacuum packing system for seed storage.
Construction:
1. Disassemble the bicycle pump and reverse the leather or rubber cup on the end of the plunger rod (A).
2. Remove the check valve in the bicycle pump because it checks the airflow in the opposite direction. This check valve is located at or near either end of the hose. In some cases, the check valve can be disengaged by removing the valve, inverting it and reinserting the valve in the pump for storage.
3. Attach a "Presta" type bicycle inner tube stem valve (B) on the lid (D) or attach a "Schrader" type check valve (B') in-line with the hose that connects the modified bicycle pump to the lid (D). The "Schrader" valve core has spring tension. For ease of pumping, disable the spring tension by cutting and removing the spring. The "Presta" valve core does not have spring tension. The body of the "Presta" valve is threaded, which provides for ease of attachment on the lid (D). Both "Presta" and "Schrader" check valves must be attached in the proper direction to allow air to be evacuated from the vacuum chamber (G).
4. Drill or cut 2 holes in the lid (D) and rubber gasket (E). One hole is for the "Presta" valve or for a hose nipple when using an in-line "Schrader" valve. The other hole is for a rubber stopper (C). The lid should be thin and slightly flexible to facilitate the sealing of the uneven surface of the food can (G) with the gasket (E). A gasket (E) made from tire inner tube may have ridges, which provide air passageways and vacuum leakage. These ridges must be filed or sanded down flat.
5. Options:
a. When using tall food jars (F), construct a taller vacuum
Chamber (G) by soldering 2 cans together.
b. A tall cooking pot can be used as the vacuum chamber (G).
c. A pressure cooker can serve as the lid (D), gasket (E) and vacuum
chamber (G).
Operation:
Place seeds in a jar with resealable lid (F) for example, a spaghetti sauce jar with "safety lock" or "pop up" button on the lid or canning jar with mason dome lids. Secure the jar lid by twisting it on snugly but not too tight so air can escape from the jar during evacuation. The jar is placed in the vacuum chamber (G). Cover the vacuum chamber with the rubber gasket (E) and lid (D). Cover the open hole with the rubber stopper (C). Attach the pump hose on to the lid stem valve ("Presta" valve) or hose nipple (when using an in-line "Schrader" valve). Evacuate the chamber and then release the vacuum rapidly by removing the rubber stopper (C). The rapid refilling of air into the chamber will slam the jar lid down and seal the jar.
A 6 inch (16 cm) diameter x 6.5 inch (17 cm) vacuum chamber requires
8 to 20 strokes on the modified bicycle pump 1.6 inch diameter x 24.4
inch (4 cm diameter x 62 cm) to attain a suitable vacuum for sealing.
Under these conditions, 15 to 25 inches of mercury (50-to 80 kilopascal)
suction can be achieved. Larger vacuum chamber requires more strokes.
Hand Operated Winnower
By Allen Dong and Roger J. Edberg, PO Box 413 Veneta, OR 97487
Public domain
A Rectangular sheet metal air duct, 24 inch long x 10 inch wide x 3-½
inch deep, available from heating and ventilation supply houses.
B Sheet metal tray, make your own.
C Sheave (V- belt pulley), 14-inch diameter, available from WW Grainger
(3X943 or 3X942) (1-800-323-0620).
D Crank handle, make your own.
E V-belt.
F Blower with 9-½ inch diameter wheel (4C589) or larger, available form WW Grainger.
G Sheet metal cover and adapter to merger blower (F) with air duct (A).
H Sheave, ½ inch bore, 1 ½ diameter and a pillow block, ½ inch diameter bore
I 1 x 2 inch steel channel or 2 x 4 inch wood upright support.
J 1 x 2 inch steel channel or 2 x 4 inch wood base for winnower.
Operation:
The winnower separates seeds from chaff by blowing the less dense chaff
away as seeds fall down a column of air. Place the seed and chaff mixture
on the tray (B). Turn the crank handle (D) and move the seed mixture into
the air duct (A). Manually adjust the crank speed to provide enough airflow
to lift the lighter chaff up and out the top of the air duct, while allowing
the denser seeds fall through the bottom of the air duct.
Construction (brief description):
The air duct (A) is purchased from a hardware store. Cut a 2 x 9 inch slot across the air duct, 6 inches from the end. This slot receives the tray (B), and allows seed and chaff on the tray to be introduced into the air duct (A). The tray (B) is made from a 16 x 24 inch, 20-gauge sheet metal. Fold 3 sides up 3 inches and fold the fourth side down 1 inch to make a 10 x 20 inch tray. Trim the fourth side ½ inch from both ends leaving a 9-inch lip that inserts and hooks on to the 2 x 9 inch slot in the air duct (A).
Attach the upright supports (I) to the blower (F) with the blower tilted up 22 ½ degrees, 6 inches off the ground and the axle of the blower wheel is centered on the pillow block/sheave (H). Make base (J). Attach supports (I) to base (J). If supports (I) and base (J) are made from 2 x 4 wood, add diagonal braces (not shown) to strengthen the join. No additional brace is needed if the upright supports (I) and base (J) are 2 inch steel channels and are welded together. A spacer is attached across the top of the two upright supports (I), (not visible in diagram). The spacer provides bottom support for the tray (B). The 14-inch sheave mounts on to the upright support using a rigid pillow block or two self-aligning pillow blocks, one on each side of the upright support.
Make a sheet metal cover and adapter (G) to merge blower (F) with air duct (A) at 45-degree angle between blower and air duct. A 45-degree air duct elbow can be used as part of the adapter. The sheet metal cover leaves a 1-½ inch gap at the bottom of the blower (F) for air to discharge into the air duct (A). Place a ¼ inch mesh screen (not visible in diagram) across the 1-½ inch gap to prevent debris from entering into the blower.