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1.
Material Pre‑treatment
- The
moisture content of pistachios shall be appropriate, generally
8-10%. The shells of too wet pistachios are soft and cannot be
cracked, and the kernels of too dry pistachios are highly prone
to breakage.
-
Remove hard foreign objects such as stones, iron pieces and wood
sticks from raw materials. Hard objects will damage the shelling
rollers.
- Raw
materials must be graded. Process large‑sized
and small‑sized nuts separately.
Without grading, the kernels of large nuts will be broken while
small nuts are not shelled completely.
2.
Equipment Inspection
- Check
the wear condition of squeezing rollers. Replace rubber rollers
promptly if grooves appear or rubber falls off. The shelling
effect will deteriorate significantly when the roller surfaces
are worn.
-
Inspect the lead screw spring adjustment mechanism. Ensure
uniform clearance on both sides of rollers. The uneven gap (wide
on one side, narrow on the other side) is not allowed.
- Check
the tension of all drive belts. Verify whether the vibrating
sieve mesh is damaged or loose.
-
Ensure the fan air ducts and discharge outlets are not blocked
by debris.
3.
Commissioning Key Points
(1)
Roll gap adjustment: Set the gap slightly smaller than the
diameter of pistachios of the corresponding gear.
‑ Excessive gap: A large quantity of
shells cannot be cracked, resulting in low shelling rate.
‑ Insufficient gap: A large number
of kernels will be crushed, and whole‑kernel
rate is reduced sharply.
Recommendation: Start with a larger gap, then reduce the gap
gradually. Take samples to check the shelling effect and kernel
breakage condition, and adjust the gap to the optimal balance
point.
(2) Fan
air volume
‑ Excessive air volume: Light half
kernels and broken kernels will be blown away, causing material
loss.
‑ Insufficient air volume: The
shells cannot be removed thoroughly, leading to high shell
content in finished products.
(3)
Vibrating sieve amplitude and feeding speed
‑ Do not feed materials too fast.
The excessive feeding volume is prone to causing material
blockage and higher kernel breakage rate.
‑ Keep moderate amplitude for the
vibrating sieve. Too small amplitude results in poor screening,
and too large amplitude increases the kernel impact and breakage
rate.
4.
Operation Notes
(1)
While the machine is running, do not put hands into the feeding
inlet, rollers or sieve box to avoid pinching injury.
(2)
Take samples at any time to monitor three indexes: shelling
rate, broken kernel proportion and shell content of finished
products. Fine‑tune the gap and air
volume as needed at any time.
(3) Do
not circulate the unshelled returned materials for too many
times. Repeated squeezing will increase the kernel breakage
rate.
(4) If
abnormal noise or jamming occurs, stop the machine and cut off
power immediately before troubleshooting. Never perform
maintenance while the machine is powered on. |
