I saw that the Delphi Encryption Compendium has a 3TDES algorithm (https://github.com/luizvaz/DelphiEncryptionCompendium/blob/4cf00a54d4ca9d6f356c1ffa1106f4be017bb6d4/Source/Cipher1.pas#L54). It is noted that its block length is 24 bytes. Is this some kind of non-standard type of 3DES encryption? And what means "168 bits relevant"?
Are there other libraries that implement a similar algorithm?
No, TDES always has a block size of 64 bits / 8 bytes. It is required to use specific techniques to expand a block size in a way that is cryptographically secure. Just repeating a block cipher (in either encryption or decryption direction) does not change the block size.
It means that the author of the source cannot be trusted to write anything, least of which a cryptographic library. Looking for issues I quickly found that Rng is an LFSR, which is a non-secure PRNG.
Don't use or trust single person libraries that do not have enough backing or a thorough security analysis.