Flat Earth in the Koran

I'm not a fan of most of the arguments that the Koran teaches that the earth is flat, because most rely on descriptions that can simply be understood as metaphors, analogies, or explaining things in human terms.  There is an exception:

And they ask you, [O Muhammad], about Dhul-Qarnayn. Say, "I will recite to you about him a report." Indeed We established him upon the earth, and We gave him to everything a way. So he followed a way until, when he reached the setting of the sun, he found it [as if] setting in a spring of dark mud, and he found near it a people. Allah said, "O Dhul-Qarnayn, either you punish [them] or else adopt among them [a way of] goodness." He said, "As for one who wrongs, we will punish him. Then he will be returned to his Lord, and He will punish him with a terrible punishment. But as for one who believes and does righteousness, he will have a reward of Paradise, and we will speak to him from our command with ease." Then he followed a way until, when he came to the rising of the sun, he found it rising on a people for whom We had not made against it any shield. Thus. And We had encompassed [all] that he had in knowledge.

That is the Sahih International translation of Surah 18:83-90.

This passage of the Koran makes it look as though the author thinks that the sun sets in a particular part of the world, a place where there is a spring of dark mud, and that there are people who live in that place.  Likewise, there is a place where the sun rises, and the people there don't have a shield from the sun.

Is there some way that this passage can be reasonably understood not to mean what it appears to mean?  I welcome explanations from Muslims in the comment box. 

-TurretinFan