Pumps, dosing

In this case, the co-solvent dosage rate is programmed in order to control the transient level of supersaturation in an effort to improve on the product crystal size distribution from simply dumping in all the solvent at the start of the batch. An experimental crystallizer within which a programmed microcomputer determines the set point of a variable speed-dosing pump is shown in Figure 7.7. Controlled co-solvent dosing improves the product crystal size, with a consequent increase in the filterability of the product. These process concepts are developed further in Chapter 9. 

Water-treatment plant may include one or more electric motors driving feedwater pumps or dosing pumps. Dosing pumps are usually very small and will not cause noise problems. Water pumps may be considered as for the feedwater pumps already described. 

The use of a chemical agent as an anti-foam is affected by an on-off algorithm with variable dosing time and time delay. If the presence of foam is detected, then the controller first activates a delay timer. This type of foam controller works with some delay and variable dosing time. If at the end of the delay period the foam is still present, then the dosing pump is activated and chemical agent is added to the bioreactor. If the foam is still detected at the end of this period, the combined system of delay and dosing is reactivated. With this method of controller, addition of any unnecessary anti-foam is prevented. 

Phosphate precipitant treatments should almost always be added directly to the boiler shell or drum, or to the FW line as close as possible to the boiler. (The phosphate dosing pump should be interlocked with the FW pump when dosing to the FW line.)... 

Hydroquinone is not very soluble and, in order not to risk plugging dosing pumps or chemical feedlines, formulations tend to be dilute. 

A means of adding liquid chemical treatment to a FW tank by means of an overhead dripping container rather than by use of a dosing pump. From a control viewpoint, drip feed is most usually unsatisfactory as the feed rate reduces over time with decrease in treatment head pressure, and ultimately the device tends to gum up. 

Pro-Minment Dosing Pumps - Models ElOOO/T and ElOOO/S Prominent Fluid Controls (UK) Ltd, Queen s Drive,... 

OTC Otrivin Measured-Dose Pump with Moisturizers, Otrivin Nasal Drops, Otrivin Nasal Spray, Otrivin Nasal Spraywith Eucalyptol, Otrivin Nasal Spray with Moisturizers, Otrivin with Measured-Dose Pump Cfiemical Class Imidazoline derivative... 

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. 

Variable and often low levels of chemical reserve, leading to a variety of product performance problems. Often as a direct consequence of having no chemical dosing pumps on-site, or inadequate, automatic control systems, or insufficient attention to the quality of makeup water employed, or maintenance of cycles of concentration. 

Chemical dosing pumps are installed. There is no automatic bleed system installed. 

Does the customer s management fully understand what is required from their side and can they actually deliver the necessary supervisory and manpower support For example, changing from a system of simple chemical dosing pumps to a microprocessor-controlled product residual tracing and addition system will probably require more equipment inspection and calibration time. It will also require a high degree of instrumentation skill. 

There are many open recirculating cooling systems that still do not have chemical dosing pumps available. This represents a serious risk, as the... 

This failure to provide dosing pumps is not good practice, as under almost every circumstance untreated cooling water systems will suffer from diminishing levels of efficiency, higher than necessary operating and maintenance costs, and shorter equipment life spans. 

Without chemical dosing pumps and adequate program control measures, the matching of chemical usage to operational needs cannot be properly achieved, which may well produce the same result as if no treatment had been used. 

Dosing pump ancillary items include chemical supply tanks (day tanks), tank mixers, flow indicators and controllers, level controllers and alarms, bulkhead fittings, corporation stops, and injection quills. 

However, given that that many biocides are hazardous to handle, a dosing pump may be a useful measure. Thus a suitable compromise may perhaps be to pump biocide to the cooling system, when tests or observation indicate a need, and to employ a manually initiated limit timer to actuate the pump. Typically, limit timers have an adjustable 0- to 90-minute timer cycle, with a 13 to 15 A output to a chemical metering pump. 

It is often found that, where reasonably generous control limits are agreed, the rises and falls in inhibitor reserve will be self-correcting and not require a slavish attitude to dosing pump adjustment. Nevertheless, the program minimum inhibitor reserve should still be sufficient to always provide adequate system protection, so a hands-off approach to pump adjustments will inevitably result in somewhat higher costs than are possible. 

Many service companies offer monitoring and communications software to provide automatic adjustment to chemical dosing pumps or bleed valves, based on receiving inputs from inhibitor tracing and tagging systems that may operate in real-time, semicontinuously, or after-the-fact modes. 

Adjustable flow-rate chemical dosing pump 356 ... 

To improve leveling a nonionic or amphoteric auxiliary agent is used. In the case of fiber-affinitive agents, the sum of the dye anions and auxiliary anions should not exceed the binding capacity of the fiber to avoid blocking effects [105], The use of computerized dosing pumps for dyes and acid permits reliable control of dye sorption [105a]. 

A 14] Micro fluidic pumps with dimensions small enough to be connected inline with the process flow of a micro structured reactor plant are commercially available [78]. The tooth-ring gear pumps of the mzr-series, for example, convey up to 171 h-1 at pressures up to 80 bar. They can be used either as dosing pumps or as booster pumps inline in a hybrid plant or in a micro structured reactor plant with open architecture. The use of the stepwise pressure increase reduces the average plant pressure as indicated schematically in Figure 4.81. 

Preparation of ethyl dichloride. Synthesis reactor 7 (Fig. 106) is continuously fed through dosing pumps with phosphorus thiotrichloride and absoluted ethyl alcohol from batch boxes 2 and 3 accordingly. 

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