Pulp and Paper

Pulp and Paper

Pulp and Paper

No damage when in steam turbine by-pass

In the process of making paper, steam is used in the drying section of the paper mill  to dry the rolls of sheet paper; compressed sheets are routed over steam heated drying cylinders to evaporate moisture from the sheets. If the paper sheet in the dryer tears, the steam supply to the heater stopped immediately resulting in a steam turbine by-pass occurrences.

In this situation all of the steam flow to the steam turbine inlet will be routed directly to the deaerator. The deaerator itself has to be able to handle a sudden large increase in steam flow. In tray type deaerators this often results in severe damage to the tray section.

This problem does not exist in a Stork spray type deaerator since it has no trays and also because the steam flows into the deaerator under the water level via the steam rake. The steam turbine by-pass case is taken account of during the design of the deaerator and the steam rake will be designed in such a way that it can successfully handle the suddenly higher steam flow during by-pass mode. In addition, the water bulk in the deaerator dampens the effect of increased steam flow thus providing for flawless operation during by-pass situations.

Compact design

System designers for pulp and paper plants often request large deaerator retention times. Retention times of 15-30 mins. are not unusual. The combination of retention time sizing and a relatively large demin water flow can result in deaerators of significant dimensions. The integral design of the Stork spray type deaerator offers benefits due its more compact design compared to a tray type deaerator. This means that the client can save on civil building and installation costs.

Increased availability

As in any other production environment, the availability of equipment is of the utmost importance to ensure continuity of production, (in this case of pulp/paper).
Due to the robust design of the Stork spray type deaerator, the tray-less design and because sprayers do not need to be replaced, the resulting availability is far superior to that of a tray type design.

 

New Klabin project

  Oki Sumatra 
 
Type: Pulp and Paper    Type:             High Energy Recovery Boiler for a paper mill
Output: 1.5 million tons of paper/year   Output: Firing capcity of 11.600 tons of dry solids per day
(equivalent to daily average electric power of a European
city of one million inhabitants
Features:     Features: Biggest recovery boiler worldwide
Deaerator size: Ø4700 x 37500 mm   Deaerator size:

 Ø6000 x 39594 mm

Year of delivery: 2014   Year of delivery: 2015
Outlet flow: 1500 t/h   Outlet flow:  
Operating pressure: 2.63 Barg   Operating pressure: 4.16 bara
Gross volume: 503 m3   Gross volume:  
Total weight:     Total weight: 195 tons
Performance:  7 ppb   Performance:  7 ppb
Design code: ASME VIII Div 1   Design code: ASME VIII Div. 1 Ed. 2010, Addenda 2011 with U-stamp