MIL-HDBK-1191
17.11.6.3
Pneumatic Trash / Linen. Pneumatic Trash / Linen shall be fully
pneumatic, gravity pneumatic or multi-loading. Hybrid systems are permitted
where required.
In general, no station shall be designed that is "up-send"
in nature. All materials should travel in the down direction after first
being loaded into the system. Verify system traffic capabilities by detailed
traffic studies.
a. Gravity-pneumatic systems, a combination of gravity chutes for
vertical transportation and pneumatic chutes for horizontal
transportation, are subject to the same fire protection requirements
as gravity systems.
b. In composite systems, the gravity chute will be equipped with a
storage section at the bottom of the chute. Gravity chute charging
stations equipped with electric control systems may be loaded with as
many bags of waste or linen as necessary. Bags are accumulated in
the storage section and are removed as a single load on demand.
c. Fully automatic chute systems containing both horizontal and vertical
elements, with automatic transfer systems, are not normally allowed
in health facilities. Where a vertical rise is required for a
pneumatic chute intended as a collector for gravity chutes, the
vertical rise must be installed in a fire-rated enclosure in
accordance with NFPA 82.
d. If horizontal pneumatic chutes must be manually charged, enclose
charging doors and frames in fire-rated rooms. Sprinklers in the
charging stations must protect pneumatic chutes. Charging stations
will have a receiving compartment with an outer and inner door. When
the door is opened to put in a load, the inner door will be
automatically locked so that the load cannot freely enter the chute.
When the outer door is closed, the inner door will open in its
sequential turn and the load will be automatically transported by
negative pressure to its point of discharge. Only one load will move
through each leg of a pneumatic chute system at one time.
17.11.7
Unit Handling Systems.
17.11.7.1
Manual Systems. Use manual systems where semi, or fully automated
systems cannot be functionally, physically or economically (LCC) justified.
17.11.7.2
Pneumatic Tubes. Pneumatic tube systems may be provided where
economically justified. Design systems to reach individual project peak
traffic requirements, plus a minimum spare capacity of 20%. Designs shall
provide for soft handling of all systems where laboratory specimens and other
delicate items are transmitted. No specific correlation can be made between
the number of beds in a health facility and the need for a pneumatic tube
system. Provision of pneumatic systems must be consistent with requirements
for a particular health facility regardless of the size of the facility.
Select tube systems which provide automatic control of carrier movement. A
selector device which permits correspondence with any station served by the
system will set destination of the carrier.
17.11.7.3
Automated Box Conveyors. Automated Box Conveyors systems may be
provided when economically (LCC) justified. Design systems to serve peak
traffic requirements plus a minimum spare capacity of 35%. Selective vertical
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