Mixer batch

Paste Mixing. The active materials for both positive and negative plates are made from the identical base materials. Lead oxide, fibers, water, and a dilute solution of sulfuric acid are combined in an agitated batch mixer or reactor to form a pastelike mixture of lead sulfates, the normal, tribasic, and tetrabasic sulfates, plus PbO, water, and free lead. The positive and negative pastes differ only in additives to the base mixture. Organic expanders, barium sulfate [7727-43-7] BaSO carbon, and occasionally mineral oil are added to the negative paste. Red lead [1314-41 -6] or minium, Pb O, is sometimes added to the positive mix. The paste for both electrodes is characterized by cube weight or density, penetration, and raw plate density. 

CViange-Can Mixers Change-can mixers are vertical batch mixers in which the container is a separate unit easily placed in or removed from the frame of the machine. They are available in capacities of about 4 to 1500 L (1 to 400 gal). The commonest type is the pony mixer. Separate cans allow the batch to be carefully measured or weighed before being brought to the mixer itself. The mixer also may serve to transpoi the finished batch to the next operation or to storage. The identity of each batch is preseiwed, and weight checks are easily made. 

Screw-Discharge Batch Mixers A variant of the sigma-blade mixer is now available with an extrusion-discharge screw located in the saddle section. During the mixing cycle the screw moves the material within the reach of the mixing olades, thereby accelerating the... 

Two-Roll Mills These mills contain two parallel rolls mounted in a heavy frame with provision for accurately regulating the pressure and distance between the rolls. As one pass between the rolls does little blending and only a small amount of work, the mills are practically always used as batch mixers. Only a small amount of material is in the high-shear zone at any one time. 

Scale-Up of Batch Mixers The prime basis of scale-up of batch mixers has been equal power per unit volume, although the most desirable practical criterion is equal blending per unit time. As size is increased, mechanical-design reqmrements may hmit the larger mixer to lower agitator speeds if so, blend times will be longer in the larger... 

Sometimes a system of mixing and dispersing is composed of one or more batch units providing a feed to a continuous intensive dispersion unit. Another possibihty would be a batch mixer and surge bin which provide a continuous feed to a final dispersion unit. Various combinations of this type with adequate samphng at the proper points may be used when continuous flow would be beneficial provided that certain features could be overcome. 

The kinetics of the reactive compatibilization of nylon-6-PP by acrylic acid modified PP was investigated by Dagli et al. [47]. The compatibilization reaction in this system involved the reaction between the acid group of acrylic acid modified PP and the amine group of nylon-6. A typical intensive batch mixer torque (t) vs time (t) trace for a ternary blend showing an increase in mixing torque upon the addition of PP-g-AA to a binary PP-NBR (85 7.5) blend is shown in Fig. 3. The kinetic... 

With a history of more than 25 years, the free radical-induced grafting of MAH onto polyolefin substrates is one of the most studied polyolefin modification processes.29 "29, 302 The process has been carried out in the melt phase, in various forms of extruders and batch mixers, and there are numerous patents covering various aspects of the process. It has also been carried out successfully in solution and in the solid state. The materials have a range of applications including their use as precursors to graft copolymers, either directly, or during the preparation of blends.297... 

Various (meth)acrylic monomers have been successfully grafted onto polyolefins. Most studies deal with functional monomers. Grafting yields obtained with PP are usually low (<20%) and are dependent on the particular monomer. Liu et al.jM carried out a comparative study on the grafting of various functional methacrylates onto PP. The experiments were performed in a batch mixer at 180 °C with 7 wt% monomer and 0.05 wt% 22 as an initiator. Grafting levels (wt%) obtained under these conditions were as follows HPMA (I), TBAEMA (1), GMA (0.8), IIEMA (0.4), DMAEMA (0.3), 32 (0.2). Grafting yields to PE appear generally higher. 

Batch mixers typically consist of a large chamber heated by oil or electricity, containing intermeshing mixing blades that homogenize the resin with the additives. A much simplified schematic of a batch mixer is shown in Fig. 12.4. A weighed amount of polymer pellets drops into the chamber and is mixed and heated until molten. Once the polymer melts, the required quantities of additives are introduced. The material then mixes until the additives are hilly... 

Create a table listing two or more advantages and disadvantages of each of the following compounding systems batch mixers, continuous mixers, single screw extruders and twin screw extruders. 

Biscuits can be mixed in most sorts of mixer. Continuous and batch mixers are both used. Some of the batch mixers are vertical others are horizontal. It might be thought that, as biscuits are often shaped and baked continuously, a continuous mixer would be essential. In practice, dough can always be mixed faster than it can be used, so a continuous mixer is not essential. 

The motivation for the investigation of a pipeless plant as an alternative production concept was the increasing product diversification and the decrease of the individual production volumes. It is expected that the capacity and the flexibility of the existing standard multipurpose plant that consists of several batch mixers will be not sufficient to meet the market demands and to stay economically competitive in the future. 

Comparison ofthe Plant Concepts To be able to compare the pipeless plant concept with the existing multipurpose batch plant, a reference plant was modelled using PPSiM. In the existing plant three conventional batch mixers work in a shifted parallel fashion. The three batch mixers were modelled by three stations and equipped with all technical functions necessary for the production of all recipes. Therefore each batch could be processed at one of the stations and the vessel transfers were limited to the transportation of empty or loaded vessels. All the other parameters of the model, e.g., charging mass flows, the durations of vessel cleanings and the recipes remained unchanged. 

Batch microwave reactors, reactions in, 16 554-555 Batch mixers, 16 721 Batch mononitrotoluene process, 17 265 Batch multipurpose plants, for fine chemical manufacture, 11 427 Batch nitrobenzene process, 17 252 Batch-operated settling tanks, 22 59 Batch pilot plants, 19 458 Batch plants, certified, 20 703 Batch polymerization, of vinyl acetate, 25 608... 

---