You can learn more from these patents:
1975 Patent 3917564 Disposal of Industrial and Sanitary Wastes, Mobil Oil
1985 Patent 4666585 Disposal of Petroleum Sludge, Atlantic Richfield
1988 Patent 4968407 Sludge Dewatering and Destruction within a Delayed Coking Process, Foster Wheeler
1989 Patent 5009767 Disposal of Industrial and Sanitary Wastes, Mobil Oil
RE Temperature, yes, that’s during the sludge injection initially in the quench phase after steamout.
RE vendors, all the DCU licensors (AFW, BHTS, Lummus) can design/build the system for you. Veolia and a few other companies can provide the sludge pre-treatment.