-
公开(公告)号：FR1319270A
公开(公告)日：1963-02-22
申请号：FR893796
申请日：1962-04-09
Applicant: BASF AG
Inventor： HANSEN GUENTER , BELZ OTTO
IPC: B01D9/00
-
-
公开(公告)号：GB994379A
公开(公告)日：1965-06-10
申请号：GB1327262
申请日：1962-04-06
Applicant: BASF AG
Inventor： HANSEN GUENTER , BELZ OTTO
Abstract: In a process for depositing crystals from aqueous solutions using heat exchangers, the rate of alestration of heat from the solution is controlled and incrustation of the heat exchanger is prevented by measuring and regulating the temperature and/or feed rate of the solution and/or the temperature and/or feed rate of the coolant in such a way that the heat transfer is limited to a maximum within the range of 6000 to 15000 K Cals per hour per sq. metre of heat exchange surface, depending on the differential velocity between the solution and the heat exchange surface. The process may be controlled manually or automatically and may be used for aqueous solutions of organic or inorganic salts, e.g. alkali metal salts, NaNO3, or (NH4)2SO4, NH4Cl. Coolant is supplied to the heat exchanger at an elevated temperature during the first few minutes. If one medium is supplied at a constant rate and the temperature difference between the feed and discharge of this medium is increased or decreased, the feed rate of the other medium is decreased or increased respectively. If one medium is supplied to the heat exchanger at constant rate and the temperature difference between the feed of the one medium and the discharge of the other medium is increased, the feed rate of the other medium is increased, and vice versa. If the solution and coolant are supplied at constant rates and the temperature difference between the feed and discharge of the solution is increased, the temperature of the coolant is raised, and vice versa. If the solution is supplied to a heat exchanger at a constant rate and at a constant temperature and the discharge temperature of the solution is increased, the feed rate of the coolant is increased and vice versa, or if the coolant is supplied at a constant rate and a constant temperature and the discharge temperature of the coolant is increased, the feed rate of the solution is decreased, and vice versa. In batchwise operation the feed rate of the coolant is increased when the change in temperature of the solution measured at equal time intervals becomes smaller, and vice versa. In an example, a solution of NaNO3 saturated at 44 DEG C. was cooled with water at 13 DEG C. in a glass tube cooler at a heat exchange rate of 6900 K Cals per square metre per hour. Alternatively, a rotating cooling drum may be used.ALSO:In a process for depositing crystals from aqueous solutions using heat exchangers, the rate of abstraction of heat from the solution is controlled and incrustation of the heat exchanger is prevented by measuring and regulating the temeprature and/or the feed rate of solution and/or the coolant in such a way that the heat transfer is limited to a maximum within the range of 6000-15000 K Cals per hour per square metre of heat exchange surface, depending on the differential velocity between the solution and the heat exchange surface.
-
-
Search Results
3
records
(took 0.021 seconds)
