What is the reason for the large solvent loss? Direct answer: The loss is concentrated in five links-tank breathing evaporation, loading and unloading and feeding escape, process volatilization, recovery device efficiency decline, leakage and leakage; check the material balance first, allocate the difference between input and output according to the link, focus on which link the difference falls on, and the scope of check is very narrow from the beginning. It is not uncommon to skip the measurement and directly upgrade the equipment, but the loss point actually lies in the management link. After the measurement is completed, the money is spent on the point. In this paper, the characteristics of the five loss points and the method of investigation clearly, according to the single investigation can be.
Material balance is the starting point of investigation: the difference between solvent input, product take-away, recovery and entrusted disposal in the statistical cycle is the unexplained loss. There is no uniform red line for the ratio of the difference to the input, which is more meaningful than its own historical data, and a rise in the ratio indicates that there are new problems in the link. The balance sheet is made on a monthly basis, and the loss change is in line with the process adjustment and seasonal change, and the scope of investigation is immediately narrowed by half. For enterprises that do not have detailed accounts, first supplement the meter and ledger, and then talk about investigation.
Storage tank respiration is a continuous loss: in seasons with large temperature difference between day and night, the exhalation and inhalation of gas in the tank bring saturated oil and gas out of the tank little by little. The loss of floating roof tank and nitrogen sealed tank is obviously lower than that of fixed roof tank, which is given priority in the renovation of old tank. Loading and unloading and feeding are large intermittent: open feeding, non-closed joints, tanker loading and unloading of instantaneous replacement, a single amount is not too large to hold the frequency, replaced by closed joints and balance pipes to improve immediately. The two points followed the smell and oil traces during the inspection, and the high incidence positions could not be hidden. The two losses in seasons with high temperature and more work are amplified simultaneously. Compared with the difference between winter and summer, the suspected link can often be directly locked.
Process volatilization is related to reaction temperature and exposure time, which is a design-level problem. The cost of modification is high, and it is recorded before evaluation. The decline in the efficiency of the recovery unit is an easy-to-ignore link: fouling of the heat exchange surface, membrane module pollution, and saturation of adsorption materials will cause the recovery volume to quietly decline, resulting in an extra piece on the loss account-the recovery volume is recorded on a monthly basis and compared with history, with a decline of more than 10 percent to arrange maintenance. The leakage is hidden in the packing and gasket of the pump valve flange. Regular fastening and pad replacement is the basic lesson. It is too late to start work after smelling the smell.
| Loss point | Feature | Governance Action |
|---|---|---|
| Tank Breathing | Persistent occurrence associated with temperature differences | Nitrogen sealing or internal floating roof modification |
| Loading and unloading escape | Focus on the operation instantaneous | Closed joint and balance pipe |
| process volatilization | Related to temperature exposure | Record before evaluating the retrofit |
| Recovery efficiency drop | Recycling volume trend down | Arrange maintenance by sectional effect measurement |
| Running, dripping and leaking | Odor of oil stain on flange of pump valve | Fastening pad replacement regular inspection |
| Missing measurement | The accounts are not aligned. | Supplementary Table Meter and Account |
There is no unified red line, which is more meaningful than its own history: the investigation will be started when it goes up for two consecutive months; The caliber of the same industry can be used as a reference, but the process and solvent varieties are quite different, and copying other people's figures is easy to misjudge.
Depending on the tank condition: the tank structure is good to do nitrogen sealing transformation investment is not large, the old fixed top tank combined with the internal floating roof transformation to do more cost-effective; Before the transformation, the respiratory loss should be measured and the plan should be determined after the account is clear.
Manage first. The management actions such as fastening, pad changing, sealed feeding and ledger metering have small input and quick effect. After finishing, we will look at the remaining difference, and the part that needs to be equipped will be decided according to the account.
This article by LuoyangWohong PetrochemicalEquipment Co., Ltd. arranges that the company provides design, manufacturing and operation and maintenance services for condensation recovery, membrane separation recovery and complete solvent recovery devices for chemical and pharmaceutical enterprises. If you need process evaluation or scheme configuration, please contact and exchange.
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