When converting pdf files through Calibre it sometimes happens that some words receive unwanted spaces between the letters of the words. For instance, the word
Although becomes
A l t h o u g h in the conversion,
everything becomes
e v e r y t h i n g,
BATTLE becomes
B A T T L E,
formed a triad of becomes
f o r m e d a triad of, etcetera. In some books that I converted thousands of words become messed-up like this, making it futile to try to correct the errors.

Is it possible to prevent Calibre from wrecking words this way?

Most probably the problem originates from the fact that in the original pdf file the text is aligned justified. This has the effect that on some lines the letter-spacing becomes somewhat wider. Nevertheless the word-spacing always remains wider than the letter-spacing. Is it possible to define a minimum value for word-spacing in Calibre so that it will not add unwanted spaces within words when the letter-spacing is smaller than the word-spacing value? I have not found this option in Calibre, but I think something like this could be the solution for this problem.
Any help will be greatly appreciated.