Vacuum Deaerators
from Hick Hargreaves

MULTI-EFFECT VACUUM DEAERATORS
Hick Hargreaves' Multi-Effect Vacuum Deaerators offer the following benefits over other types of deaerator :

Substantial height reduction when compared to vacuum and gas stripping columns.

Substantial savings in weight when compared to vacuum and gas stripping columns.

Unaffected by motion of the installation, Hick Hargreaves' deaerators of similar design are installed on floating oil production facilities.

Unaffected by any foaming propensity of the water.

No reliance on catalysts which have only a limited life span and may be inadvertently poisoned.

No requirements for the storage and/or production of potentially hazardous combustion agents, e.g. methanol or hydrogen.

Only extensively field proven technology is used.

Reduced commissioning costs can be achieved by supplying the system as a single pre-assembled unit (PAU) which can be fully tested onshore.
A Typical Vacuum Pack
The use of Hick Hargreaves' deaerated water extraction pumps which have been designed to operate with less than one metre NPSH enables the skirt height and stored volume to be minimised to further reduce column height. The performance characteristics of these pumps are easily matched to an injection pump. The deaerated water extraction pumps can be built into a single package with the vacuum equipment and deaerator vessel to provide a compact pre-assembled unit.

TRACE GAS ASSISTED DEAERATORS
Hick Hargreaves' trace gas assisted vacuum deaerators combines the company's multi-effect vacuum deaeration technology with inert gas stripping to offer further reductions in deaerator column size whilst retaining all the benefits offered by the multi-effect column. A Typical Multi-Effect Deaerator Unit
The deaerator is of similar design to Hick Hargreaves' multi-effect units with a gas distribution arrangement being added below the packed bed. A calculated quantity of stripping gas is admitted via this distributor which greatly increases the efficiency of the deaeration process whilst enabling the column operating pressure to be increased above the levels normally associated with vacuum deaeration. The stripping gas used can either be nitrogen or field gas, the quantity required being only a small fraction of that required for conventional gas stripping, typically between 2% and 5% of the gas normally used.

Vacuum is maintained by a two stage liquid ring pump, the high operating pressure of the column negating the requirement for atmospheric air operated ejectors on most applications.

If a suitable field gas supply is unavailable, a nitrogen generating unit employing either membrane or pressure swing technology can be incorporated into the vacuum package to supply the small quantity of stripping gas required.

As with the multi-effect unit, the trace gas assisted vacuum deaerator can be provided with Hick Hargreaves' deaerated water extraction pumps to minimise skirt height and stored volume, further reducing column height. Both nitrogen generator amd deaerated water extraction pumps can be built into a single package with the vacuum equipment to provide a compact pre-assembled unit.