Photo: Soda Digester On PRR Flat Car (Circa 1920)


Bob Chaparro
 

Photo: Soda Digester On PRR Flat Car (Circa 1920)

A photo from the Maine Memory Network:

https://www.mainememory.net/artifact/5637

Click on the photo and scroll to enlarge it.

Description:

“S.D. Warren Paper Co. of Westbrook, Maine used this soda digester or sulphite digester fabricated at the Portland Company, which fabricated machines from steel and is one of the longest continually running factories in New England. This machine combines sulphite with the wood pulp to soften the pulp enough to create paper fiber.”

Notice the stakes placed to keep the cradles from shifting laterally and the steel(?) rods securing the load.

Bob Chaparro

Hemet, CA


Claus Schlund \(HGM\)
 


Hi Bob and List members,
 
If you zoom in enough, under the last A in PENNSYLVANIA, you can make our the class markings - it is a PRR class F23 flat, series 435445-435450 (6 cars).
 
The road number can be found over the left-most truck, but it is difficult to read, apparently both faded and dirty, it might read 4354X0, with the X obscured by the wire rope, in which case this is car 435450, but I would not bet a whole lot of money on that last part.
 
Claus Schlund
 

----- Original Message -----
Sent: Sunday, April 04, 2021 1:59 PM
Subject: [RealSTMFC] Photo: Soda Digester On PRR Flat Car (Circa 1920)

Photo: Soda Digester On PRR Flat Car (Circa 1920)

A photo from the Maine Memory Network:

https://www.mainememory.net/artifact/5637

Click on the photo and scroll to enlarge it.

Description:

“S.D. Warren Paper Co. of Westbrook, Maine used this soda digester or sulphite digester fabricated at the Portland Company, which fabricated machines from steel and is one of the longest continually running factories in New England. This machine combines sulphite with the wood pulp to soften the pulp enough to create paper fiber.”

Notice the stakes placed to keep the cradles from shifting laterally and the steel(?) rods securing the load.

Bob Chaparro

Hemet, CA


David Soderblom
 

A very modelable load. Note especially the manufacturer markings.

Sent from my tricorder


Louis Adler
 

The load looks like the bottom half of the digester.  Even batch digesters, like this one, were pressurized and were typically loaded from the top.   The cooking chemicals, sodium sulfite (Na2SO3) in this case and referred to a "liquor", attack the lignin that holds the tree fibers together.   The result is that the softened wood fibers (pulp) are extracted out of the bottom and the cooking chemicals and lignin are extracted separately to be sent to a recovery process.  What is missing (in the photo) is the capping valve assembly that would be on the top, i.e. far end of the vessel.  

For a sulfate or sulfite digester, the typical ratio of height and diameter is between 3.3 and 4. The top or bottom taper angle has a certain influence on the charge, blowing, charging of liquor and steaming. The top taper angle is about 90°and the bottom taper angle is about 60°.

A diagram of a batch digester is at this website:

https://www.google.com/search?q=batch+digester+process&rlz=1C1CHBF_enUS711US711&sxsrf=ALeKk02XdJ1cCEz4D9X4AkiIZD0w_UoAdg:1617638852185&tbm=isch&source=iu&ictx=1&fir=E1761zUlNrfrGM%252CB3oWqI6-W7DF3M%252C_&vet=1&usg=AI4_-kQph_OZcXhAhD_YjhprND0xWLZw5g&sa=X&ved=2ahUKEwi116KpvufvAhUNWs0KHXJBAPoQ9QF6BAgPEAE&biw=1487&bih=792#imgrc=V77Hdxbvk64UiM

Lou Adler