“Linear” transfer line exchangers (double-pipe design)
The BORSIG “Linear” transfer line exchangers rapidly cool down the cracked gas in ethylene plants.
The patented BORSIG linear quencher (BLQ) consists of a number of linearly arranged double pipe elements of which each is directly coupled to one of the furnace radiant coil outlets.
The process effluent from each single radiant coil is quenched individually in its own double pipe element.
A common down comer header distributes uniformly the circulating boiler water coming from the steam drum to each of the “Turbo flow” inlet chambers. A riser header is collecting the steam/water mixture from the upper outlet chambers.
The picture below shows a typical BLQ arrangement. Other arrangements are possible, even the twin leg concept if the available place in the furnace structure is limited.
The BLQ is a versatile exchanger design with a wide range of optional orientations which fulfills the specific requirements of all engineering contractors active in the design of ethylene furnaces.
BORSIG Process Heat Exchanger GmbH provides the complete quench system comprising the design of the BLQ, the riser and downcomer pipework and the steam drum.
BORSIG Process Heat Exchanger GmbH has provided over 6,000 BORSIG linear quenchers with more than 29,000 double pipes to all parts of the world since 1990.
The design has the following benefits:
- A linear quencher consists of a number of linearly arranged double pipe elements.
- Compact, modular design
- Closely and directly coupled to each radiant coil outlet
- Elimination of wye, tri or tetra fittings in the cracking furnace
- No hot tube sheet: no fouling, no erosion
- Low volume of BLQ gas side: low residence time
- Low overall pressure drop
- Online instead of off-line decoking
- Upflow or downflow arrangement
- Single of twin leg designs
- Individual exchangers
- No restriction in quench pipe diameter
- Three refractory gas inlet heads: no steam purge required
- "Turboflow" chamber design
- One common water and one common water/steam header per BLQ module
- Ease of maintenance