Elimination of common failures of three-effect evaporator Due to changes in operating conditions, use methods and other factors, the equipment often fails to operate normally, and even the concentration process is interrupted. Therefore, understanding the normal operating conditions and methods of use of enrichment equipment is essential for equipment operators and maintenance personnel.
(1) The operation of the three-effect evaporator failed. The low vacuum is too low to maintain the boiling point of the concentrate, and the temperature of the secondary steam increases, thereby reducing the effective temperature difference between the heating steam and the concentrate, reducing heat transfer and slowing down the steam evaporation rate, and the heating temperature of the heating material, Affect the preservation of active ingredients. Excessively low vacuum reduces the production capacity of the equipment in addition to the effect of concentrated quality. The reasons for low vacuum are as follows:
(1) Concentrate each part of the equipment into the air. The penetration of air increases the extra burden on the vacuum equipment and may even cause malfunctions.
(2) Insufficient cooling water. In addition to the pump equipment, the lack of cooling water is mainly due to the blockage of the pipeline, which causes the valve to be damaged. The amount of cooling water is not enough to prevent the secondary steam from being condensed in time, which seriously affects the operation of the vacuum equipment.
(3) The cooling water temperature is too high. The temperature of the cooling water entering the water is too high, the large amount of secondary steam generated by the centralized heating cannot be condensed in time, and the vacuum degree of the concentrating equipment will be rapidly reduced.
(4) The steam pressure used is too high. The heating steam pressure is too high to enrich the equipment. The evaporation rate of the equipment increases rapidly. The production of a large amount of secondary steam increases the load of the cooling equipment and gradually reduces the vacuum. Reducing the degree of vacuum will also increase the evaporation temperature of the material, at the same time affect the quality of the product, and ultimately reduce the production capacity of the equipment.
(5) The vacuum equipment is faulty.
The vacuum is too high
(1) The cooling water inlet temperature of the concentration equipment is too low, and the equipment vacuum is too high. Although the high vacuum degree increases the effective temperature difference between the heated steam and the boiling point of the material, it is advantageous to increase heat transfer and accelerate the evaporation rate. However, since the latent heat of vaporization of the secondary steam increases as the degree of vacuum increases, the steam consumption increases accordingly.
(2) The evaporation rate is greatly reduced due to low pressure or steam flow rate.
(3) In the equipment using the soft drink separator, the condensate discharge is poor due to the blockage of the water separator, which makes the heater water serious. In addition, if the quality of the heating steam is poor, or the insulation of the cold steam pipe is poor, and the water inside the heater is serious, heat transfer is difficult and the vacuum is too high.
(4) The severe coking of the heater surface reduces the heat transfer coefficient of the heating surface, the evaporation speed is reduced, and the vacuum degree of the pot exceeds the standard.
3. Pour the cooling water into the thickening equipment
(1) Than the vacuum system is suddenly cut off to vacuum. At this time, the steam is not turned off in time to destroy the vacuum in the pot, and the vacuum system pours the cooling water into the condensing equipment.
(2) Do not follow the normal operating sequence (the first vacuum device destroys the vacuum of the pan after the equipment is powered off), so that the vacuum in the pan is instantly higher than the vacuum system, and the cooling water is about to be poured out.
(3) Sudden failure of the vacuum equipment has a sharp drop in the pumping rate of the vacuum system. In this case, if no measures are taken to destroy the vacuum in the pot, the cooling water will be poured back.
Heating surface coke
(1) When the material concentration in the equipment is insufficient, the heating surface is not completely immersed in the material that opens the steam valve, and N,N-dimethyl-1,3-propanediamine has complete physical and chemical properties. The heated surface is exposed and scorched. Sudden increase in steam pressure heating during production interruption and sudden changes in operating conditions during production may cause severe heating of the heating surface.
(2) Do not operate in the order of stopping, do not close the steam valve before heating, break the vacuum first, lower the material level, and cause the surface to heat and burn.
(3) Less than the amount of material and the amount of evaporation in the normal operation of the feed