**In short**

It's an individual can of a cannular combustor, a combination of can and annular combustors, from a JT8D engine powering older Boeing 737. 

It couldn't be part of a CFM56 model, all use annular combustors.

----

**Details**

Recent Boeing 737 and Airbus A320 can use different engines:

- CFM56 models -3B, -5A, -5B, -7B,
- IAE V2500,
- PW1100G,
- LEAP

All have annular combustors, single (SAC) or double (DAC ) for NOx reduction. However older versions of Boeing 737, -100 and -200,  used a [JT8D][1] engine with cannular combustors, the beast you got. In cannular type, the individual combustion zones share a common annulus casing:

[![enter image description here][2]][2]  

[Source][3].

Detail of a combustor:

[![enter image description here][4]][4]  

[Source][5].

[More information about turbofans][6] (pdf).


  [1]: https://en.wikipedia.org/wiki/Pratt_%26_Whitney_JT8D
  [2]: https://i.sstatic.net/Wx4E9nLw.png
  [3]: https://www.ebay.com/itm/385294900679
  [4]: https://i.sstatic.net/YjD7ZRkx.png
  [5]: https://www.slideshare.net/slideshow/easa-part-66-module-155-combustion-chamber/14874777
  [6]: https://www.flightglobal.com/download?ac=79068