AirTek TW15 설치, 운영 및 유지보수 매뉴얼 - 페이지 6

{카테고리_이름} AirTek TW15에 대한 설치, 운영 및 유지보수 매뉴얼을 온라인으로 검색하거나 PDF를 다운로드하세요. AirTek TW15 20 페이지. Heatless desiccant compressed air dryer

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IMPORTANT: Just as the dryer is designed to remove only

water vapor, the moisture being purged from the saturated

regenerating bed will also be exhausted in VAPOR form. At

no time should you see liquid water being ejected from the

dryer! The only water you might see is a small amount of

condensate forming at the exhaust due to the Joule-

Thomson cooling effect created by the depressing air.

Prior to switching a freshly regenerated bed on-line to

become the drying bed, it must be slowly pressurized from

atmospheric pressure to line pressure. This step is called

repressurization. Repressurization prevents bed fluidization

(lifting) and associated dusting.

Following repressurization, the beds switch functions with

the fresh bed now drying and the saturated bed being

regenerated.

Note that one bed is always on-line drying. Also note that

purge air is always being consumed except during

repressurization.

This cycle will continue automatically unless the dryer is

shut down, operated in the CycleLoc mode, or equipped

with a demand cycle controller (PowerLoc).

A. SEQUENCE OF OPERATION:

The above sequence is controlled by a Solid State Timing

and Relay circuit (Sequence Annunciator) which in turn

controls a 4-way solenoid valve (S1: inlet switching valve)

and a 2-way NC solenoid valve (S2: purge stop/exhaust

valve).

STEP 1: LEFT DRYING, RIGHT REGENERATING

The inlet switching valve (S1) is in its default non-

energized position, directing all the wet inlet air to the left

tower. The air is dried as it passes through he desiccant bed

at system pressure, typically 100 PSIG. As the air exits the

tower fully dried, the bulk of the air is directed downstream

via the outlet check valves.

Approximately 15% of the dried air is directed to the right

tower via the purge controls. This purge or regeneration air

is reduced to atmospheric pressure (0 PSIG) by the time it

enters the right tower. This super dry, low pressure purge

air flows down through the desiccant bed, stripping accu-

mulated moisture. It is directed via the inlet-switching valve

through the purge stop solenoid (S2), which is energized

and open. The moisture laden purge air exists to atmo-

sphere through the exhaust muffler.

On TW10 & TW15 models the purge controls consist solely

of a bi-directional flow needle valve connecting the outlet of

each tower. The needle valve is adjusted to obtain the

required purge flow.

On TW25, TW40, & TW55 models the purge control

system consists of a purge filter, needle valve, pressure

gauge, orifice, and two purge check valves. The needle

valve is adjusted to obtain the specified purge pressure,

which equates to the proper purge flow.

AIRTEK

4087 WALDEN AVENUE, LANCASTER, NY 14086

STEP 2: LEFT DRYING, RIGHT REPRESSURIZING

The purge stop solenoid (S2) is de-energized and returns to

its normally closed position. This prevents the purge air

from exhausting to atmosphere, resulting in the right tower

and the purge system being pressurized to system pres-

sure.

STEP 3: LEFT REGENERATING, RIGHT DRYING

Simultaneously the inlet switching valve (S1) and the purge

stop solenoid (S2) are energized. Energizing S1 shifts the

inlet switching valve to direct the inlet flow to the right tower

where it is dried as it passes over the freshly regenerated

desiccant bed. S2 opens as it is energized "blowing down"

the left tower. Purge air now flows over the left tower,

stripping the moisture from the desiccant that was adsorbed

when the left tower was on-line drying.

STEP 4: LEFT REPRESSURIZING, RIGHT DRYING:

The purge stop solenoid (S2) is de-energized and returns to

its normally closed position. This prevents the purge air

from exhausting to atmosphere, resulting in the left tower

and the purge system being pressurized to system pres-

sure.

NOTE: The Purge Gauge (middle gauge TW25, 40, 55)

should read purge pressure, except during repressurization.

Purge flow is calculated by the Purge Formula in this

manual and checking the proper chart. Purge pressure for

standard inlet design conditions is listed on the specifica-

tions page. For other than standard or design conditions

use the purge formula and charts for purge flow/pressure

calculation, or consult the factory.

B. OPERATIONAL NOTES:

A desiccant dryer should never be suddenly pressurized or

depressurized. This will cause fluidizing and dusting.

After start-up, some dusting may occur. This will diminish

with time. Some dusting may occur with normal operation.

The Exhaust Muffler should be cleaned regularly and an

Afterfilter should be used.

Flow direction is Upflow Drying – Downflow Purge.

Switching Failure alarm is optional and the Dryer must be

operating over 70 PSI for proper function of the alarm.

During a power loss situation, the exhaust valve will close

preventing purge air loss and allowing the system to remain

pressurized. Inlet air is able to flow through one tower and

downstream.

The standard AIRTEK dryer has a design pressure of 150

PSIG. In good practice the normal working pressure should

be below 150 PSIG to prevent the safety valve from blowing

off.

Tel: (716) 685-4040

Pg. -6-

Fax: (716) 685-1010