Drying of the linings inside the two vessels
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Dear sea friends, I have a question: regarding the drying of the linings in these two devices, are there any clear regulatory requirements that prohibit natural drying and instead require drying using specified parameters? At present, only the plan and the requirements specified in it are known, but is there any guidance indicating which standards or regulations these come from?
The temperature rise curves for the two devices specify the constant temperature level as well as the rate at which the temperature should increase per hour; these specifications are intended to help dry out any moisture present in the linings of the two devices
What does it mean by “not allowing natural drying”? There is a specified curing time – why is it not allowed?
There are two types of water inside the lining: surface water and bound water. It is impossible to dry it naturally; when drying the lining of these two types of devices, it is necessary to follow the temperature increase curve strictly, otherwise the lining is likely to get damaged
1. Catalyst lining materials are generally of either air-setting or water-setting types; the former uses binders such as aluminum phosphate solutions, while the latter uses cement as its binder. 2. Water-setting linings require the addition of water during construction, which reacts with the cement to produce heat; during curing at room temperature, water mist must be sprayed to reduce the temperature. 3. If the owner has sufficient time, natural curing after the hydration reaction, relying on natural evaporation from the atmospheric environment, can remove most of the surface moisture. Just as with building concrete, its strength gradually increases over time. 4. During the hydration process, some crystalline water remains inside the lining, and it is difficult to remove this water through short-term curing at room temperature; an increase in temperature is required. The principle of the dehydration process is to proceed slowly in order to prevent stress damage to the lining caused by water vaporization; therefore, there are requirements both for the rate of temperature increase and for the time at which the temperature remains constant. 5. The specified baking time and rate are the basic requirements for baking linings with no special requirements, but they are not the only requirements.