Buffer tank

Steeping. Sheet, roU, or suitably milled flock pulp is metered into a pulper along with vigorously stirred 18% sodium hydroxide solution at 50°C. The resulting slurry, containing about 5% finely dispersed pulp, passes to a buffer tank from which it is metered to a slurry press that sieves out the swollen fiber and returns the pressings soda for concentration correction and reuse. The cellulose reacts with the soda as a complex alcohol to form the sodium salt or alk-ceU. 

Low-pressure steam is used as the heating fluid in the machine jacket. The H20/dioxane vapors are conveyed to the condenser while the stripped FAES is sucked by an extraction pump and sent to the adjustment of AM content or directly to the storage and buffering tank. Starting from FAES containing a maximum of 50 ppm of 1,4-dioxane (on 100% AM), an 80% yield of removal can be achieved by water evaporation that is markedly dependent on the applied vacuum degree. 

The test commences with a heat extraction of about 1 kW (duration 45 h), subsequently this extraction rate was increased to 1.35 kW. After a total time of 60 h, a short recovery period (10 h) was allowed. During this period the heat pump was reversed and started storing heat in the buffer tank. Subsequently a heat injection of about 1 kW was started, after which there is a transient power injection with a maximum power injection rate of about 3.4 kW. The experiment settings have to be adjusted manually, therefore some control problems are obvious in the graph. For instance, when changing to... 

Provision of sufficiently large buffer tanks for storage of spilled cooking and recovery liquors and dirty condensates to prevent sudden peaks of loading and occasional upsets in the external effluent treatment plant... 

Process vapours from the esterification reactors and EG from the EG-vapour jet, as well as from the vacuum stages of the spray condensers, are purified in the distillation unit. The distillation unit commonly consists of two or three columns and is designed for continuous operation. The purified EG is condensed at the top of the third vacuum rectification column and returned to the process via a buffer tank. Gaseous acetaldehyde and other non-condensables are vented or burned and high-boiling residues from the bottom of the third column are discharged or also burned. 

A schematic representation of a CE system is presented in Figure 9.1. In this diagram, the CE components have obvious counterparts to those found in slab gel electrophoresis. Instead of buffer tanks there are two small buffer reservoirs, and the capillary takes the place of the gel (or more accurately, a gel lane). The capillary is immersed in the electrolyte-filled reservoirs, which also make contact with the electrodes connected to a high-voltage power supply. A new feature to the conventional gel electrophoresis format is the presence of an online detection system. 

However, because both acids and bases are used in cleaning, it may be possible to store these chemicals in a stirred buffer tank to allow the solution to neutralise. This solution may then may be slowly added to the concentrate waste to dilute it and allow for a safe disposal (Mauguin and Corsin 2005). Note that the volume of this discharge is much lower than both the concentrate and filter backwash discharges. 

Coagulants, which are present in filter backwash, are of low toxicity and are not considered a major environmental concern. One of the greatest effects of coagulants comes through the use of ferric salts, which are likely to cause colouration and increase the turbidity of the backwash (Lattemann and Hopner 2008). The quantity of coagulants in the concentrate can in part be regulated by the slow release of filter backwash from a buffer tank into the concentrate flow. 

Discharge of solutions which are either basic or acid are dangerous to marine life, and should be neutralised prior to discharge. This can be achieved with a buffer tank to store and neutralise acidic and alkaline solutions with each other. Seawater may also be used to neutralise cleaning solutions. 

Place the slide on the cooling plate of a horizontal electrophoresis apparatus, fill the tanks with 1 1 diluted Soln. B, and connect the ends of the slide to the buffer tanks by wetted filter paper wicks. Run the electrophoresis at 6 V/cm for about 45 min. Stop electrophoresis when bromophenol blue is about 4 mm from the the wicks. 

The first station is the filling station. This station has four nozzles. Each pump can be adjusted independently. The filling operation uses four rotary piston stainless steel pumps. The dosing system, consisting of buffer tank, filling nozzles, and dosing pumps, is easily disassembled for cleaning and is steam sterilized before use. 

Buffer tank (amber Duran bottle) with buffer tank manifold Vent hlter... 

A recent processing development has been the continuous oxidizer, shown in Figure 3 (91). The charge is fed to the bottom of the column, where air is also introduced. At the top of the column the liquid overflows into a buffer tank. From this the oxidized asphalt is drawn off by means of a pump, provision being made for recirculation. 

Kyhse-Anderson, J. (1984) Electroblottmg of multiple gels- a simple apparatus without buffer tank for rapid transfer of proteins from polyacrylamide to nitrocellulose. J. Biochem Biophys. Methods 10,203—209. 

For aseptic packaging operations, flash pasteurisers are often linked integrally with the aseptic packaging unit, either directly or via an aseptic buffer tank. When flash pasteurisation is used, care should be taken to minimise product recirculation when the pasteuriser is in divert mode. Excessive recirculation can lead to thermal damage to the product, resulting in unpleasant cooked flavours and product browning. 

The powdered aminoplast is supplied from ball mill (1) to buffer tank (2) with an agitator and then to feed hopper (3) of mixer (4) wherein it is processed until a homogeneous plastic extrudate is obtained. 

Buffer tank 13. Selector controle 14. Standard solution ... 

There are other ways to reduce the need for in-process storage of hazardous intermediates. Fully understanding the causes of unreliability in production units is the key to reducing the need for in-process buffer tanks. Causes of shutdown can be eliminated by using more robust and reliable equipment, improving the process to... 

Here, by far, heat-tradng is the best solution and has been proven to work perfectly for both spring and pilot valves. But some suppliers offer a sort of clean medium barrier (for instance glycol). In this case, the pilot is only in contact with the clean medium, which is vented each time the valve opens until the buffer tank is empty (Figure 5.45). 

Pilot valve with clean medium buffer tank... 

As in a continuous flow process downstream apparatus is directly linked to upstream devices, the complete production line is interrupted in case of a failure upstream. It will be examined if this failure behavior can be corrected either by the design of several parallel lines or by supplying buffer tanks, additional spare pumps, machines,... 

How often the control loop is executed is determined by the sampling interval, which is how often the measurement is taken. A critical pressure on an exothermic reactor may be sampled several times per second, while the level of a buffer tank may only be sampled a few times an hour. The sampling time must be chosen with care to ensure that possible changes in the process are detected early enough for the controller to take appropriate action. However, sampling too often is undesirable as it may upset the process and because a large number of data points would have to be sampled and stored. 

It was further assumed that mixer and settler holdup times were the same as used in our small scale equipment. Mass transfer between the phases in the mixer was further assumed to be instantaneous to facilitate the calculations. In some cases this may lead to underestimation of solvent dose, but in other cases to overestimation. It is believed that these errors largely cancel out over the whole process. It was further assumed that a small common buffer tank was used for the purified recirculated solvents, thus giving an averaging effect on the solvent doses in the first and third cycles. 

After cooling the resin in the reactor, the resin is pumped to the buffer tank of the connected spray dryer plant. Usually, the complete batch processing takes 4-5 h. The urea-formaldehyde resin solution can be dried in a spray dryer based on co-current flow principle. 

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