Operating Principle And Method; Outline Diagram; Operation; Upstream Filtration - MIL'S SEC A Manual De Operación Y Mantenimiento

2.

OPERATING PRINCIPLE AND METHOD

2.1. Outline diagram

Downstream filtration

Upstream filtration

Amont
A - B Adsorption cylinders with dessicant
V1 - V3 Inlet valve (NO)
R2 - R4 Regeneration valve (NC)
S Exhaust silencer
C1 - C2 Non-return valve
E1 - E2 Nozzles calibrated according to regeneration flow rate
CY Cyclone filter
(only SEC 7OX / 7HC – MV version or with electro-cooler)
- - - - - - - valves control V1, V3, R2, R4
518718-12
SEC A / 1A / 2A / 7OX / 7HC –AD 5xxx
Downstream valve

2.2. Operation

2.2.1. Upstream filtration
The air goes through the upstream filtration system. The cyclone filter (CY) (only air treatment SEC 7OX /
7HC with compressor 'MV' or air treatment with electro-cooler) will eliminate 99% of liquid and the large
particles by shocks and centrifugal effect.
The pre-filter (PF) eliminates solid particles, oil or water in liquid form, using micro-fibres. The sub-micronic
filter (SUB) continues to eliminate solid particles, oil or water in liquid form and as aerosols.
In the two filters, the liquid particles obtained by coalescence gradually make droplets of increasing size.
The droplets are pushed inside the filtering element and are separated from the compressed air by a sleeve
fitted around the filtering medium called anti-reverse barrier. This barrier allows the fluid to circulate by
gravity flow into the lower part of the filtering element to form a "wet barrier" and the fluid flows down to
the bottom of the filter's housing. An automatic drainer is provided to remove any excess condensate.
In option, an electronic or sequential drainer by solenoid valve can be installed under these filters.
Note: in SEC7OX / SEC7HC version an electronic drainer BEKO 12 is installed under the Cyclone filter.
The definition of the upstream filtration system depends on the completion of the dryer:
SEC A SEC 1A SEC 2A
None PF PF + SUB
Note: The SUB filter is fitted downstream, to make up temporarily for a possible failure of the PF filter. This
situation will cause a premature saturation of the SUB filter. The failure of the SUB filter will eventually
cause a degradation of the drying, and this will be detected by hygrometry alarm S1A.
2.2.2.

Dryer / degasser by adsorption

This dryer/degasser by adsorption operates on the principle of the process of inversion of cold pressure.
It is equipped with 2 to 14 cylinders of absorption fitted in parallel (1/1, 2/2, 3/3 ... 7/7) to form the part 'A'
or the part 'B'. While the air goes through the part 'A' and is dried and degassed, the other part 'B' is
regenerated.
Part 'A' (B)* in operation
Air goes through the valve V1 (NO) (V2)*.in cylinders of absorption 'A' (B)* .The passage of the air is carried
out upwards. Cylinders are designed so as to avoid the progressive destruction of drying by shocks and
rolling. The air is dried and degassed then goes through the non-return valve C1 (C2) *.
Part 'B' (A)* in regeneration phase then pressurisation phase
At the beginning of the regeneration phase, the valve V3 (NO) (V1)* becomes non-busy then the valve R4
(NF) (R2)* opens: cylinders B (A)* are quickly depressurised and the non-return valve C2 (C1)* is closed.
The value of the pressure gauge M2 (M1)* goes from the operating pressure to approximately 0.5 bar.
During 4 minutes, cylinders B (A)* are swept with against current by dry air: the moisture and the
undesirable gases trapped by the drying are evacuated by this dry air flow to the ambient air by the valve
R4 (R2) * then by the silencer S.
This flow of air comes from the nozzle E2 (E1) which is gauged according to the performances to obtain.
SEC 7OX SEC 7HC
MV version or with electro-cooler
CY + PF + SUB
10