Karrick / KLTCUSP Capture: A Patent-and-Figure Dossier for Low-Temperature Carbonization

What this capture is

This is a source capture of the page karrick2/kltcusp.htm, filed in the archive's low-temperature-carbonization (LTC) folder. Unlike the earlier Karrick dossiers in the corpus, which carried explanatory prose about the process, this page is primarily a figure-and-patent dossier: it presents a set of GIF images, most of which are United States patent drawings, alongside supporting text.

It is the fifth Karrick-related capture recorded in this wiki. The earlier ones are the first dossier (Karrick Process and Low-Temperature Carbonization: A source Dossier (Provisional Record)), the 1jacar.htm capture (Karrick Page 1jacar.htm: A Third source Capture in the Coal Mining Library), and the image-set captures that supplied karrick1.gif, karrick2.gif and karrick3.gif (Karrick Dossier Figures: Captioned Schematics and Uncaptioned Images). The genuinely new material here is not the process description — that is already covered by Karrick Process and Low-Temperature Carbonization (LTC) — but the specific set of patent numbers whose drawings the page reproduces.

The figure and patent index

The capture's structured content is its image list. Thirteen of the fourteen filenames are bare seven-digit numbers, which in this archive's convention correspond to US patent numbers; the remaining one is a schematic-style filename. Preserved verbatim from the capture:

The mapping from filename to patent number is an inference from the archive's naming convention, not a statement the capture itself makes in readable text. The capture supplies the drawings together with patent numbers, titles and grant dates for each entry (for example, USP 1,832,219 "Process & Apparatus for Superheating Steam," Nov. 17, 1931; USP 1,913,395 "Underground Gasification of Carbonaceous Material Bearing Substances," June 13, 1933; USP 2,283,556 "Valve," May 19, 1942). It does not supply inventors, filing dates or claim language. See Karrick Patent Set (Seven US Patent Drawings in the KLTCUSP Capture) for the consolidated record and for the caveats that attach to it.

What the patents are claimed to document

The implicit claim of a page like this is that the Karrick process — and the broader low-temperature-carbonization family — is documented by a definite set of US patents whose drawings can be reproduced as a visual record. That framing is consistent with the rest of the archive's Karrick material, which treats the process as an established, patent-documented technology rather than an experimental proposal.

What the capture does not do is establish what each patent actually claims. A patent drawing shows a configuration; it does not show that the configuration was built, that it operated at the stated temperatures, or that it produced the stated yields. The distinction matters here because the seven numbers are presented without accompanying claim text, and at least some of them may belong to inventors other than Lewis Cass Karrick — the LTC field in the 1920s and 1930s included work by several groups, and the US Bureau of Mines was only one of them. Whether these seven patents are Karrick's own or a mixed set of related LTC patents is an open question this capture does not resolve.

Mechanism, in brief

The underlying chemistry is already documented elsewhere in this wiki and is not restated at length here. In outline: coal is heated in the absence of oxygen to roughly 450–700 °C, below the temperatures used in conventional coking. Volatile matter is driven off and recovered as Coal Tar and combustible gas, leaving a solid residue, Semi-Coke, that burns with less smoke than raw coal. The thermal decomposition step is Destructive Distillation; the specific variant associated with Karrick's Bureau of Mines work is the Karrick Process. Claims that the process extends into Coal Liquefaction are adjacent to, but distinct from, the carbonization step itself.

Observations and evidence

The capture's evidence is of one kind only: reproduced patent drawings. There are no reported yields, no product analyses, no operating temperatures tied to a specific run, no cost figures, and no independent replication. The archive's audit of this capture found no capture problem, so the images are likely intact — but image integrity is not the same as technical validation.

This is the same evidential situation the wiki already records in Karrick Claims vs. Evidence: The Dossier's Assertions and the Absence of Test Data. That comparison notes the absence of test data across the Karrick dossier set; this fifth capture adds seven more drawings to the visual record without adding any measurement to the evidence base. The comparison's conclusion is therefore unchanged by this source.

Limitations and unresolved questions

• Patent drawings are not demonstrations. They record a claimed configuration, not a verified result. See Patent as Evidence.
• Attribution is unverified. The capture does not, in the material available, state who invented each of the seven patents or when they were granted.
• xfig1.gif is unidentified. It may be a process schematic, a flow diagram, or an unrelated figure. The capture does not caption it.
• Redundancy. This is the fifth Karrick capture. The process narrative is already well covered; the new contribution is the patent-number index, and that index is only as useful as the patent texts it points to.
• Consolidation question. With five captures in the corpus, a single synthesis page covering the Karrick/LTC material may serve readers better than further per-capture articles. That is a curation decision, not a finding of this source.

Related work

• Karrick Process and Low-Temperature Carbonization: A source Dossier (Provisional Record) — the first Karrick dossier, which carries the process narrative.
• Karrick Page 1jacar.htm: A Third source Capture in the Coal Mining Library — the 1jacar.htm capture.
• Karrick Dossier Figures: Captioned Schematics and Uncaptioned Images — the karrick1/2/3.gif image set.
• KLTCC (Abbreviation in the Karrick Dossier Image Set) — the abbreviation appearing in the Karrick image set.
• NTU Retort (Rifle-Coal Retort Design in the Karrick Dossier) — the rifle-coal retort design associated with this material.
• Karrick Claims vs. Evidence: The Dossier's Assertions and the Absence of Test Data — the standing assessment of what the dossier set does and does not establish.