Entity

Time filter

Source Type

Clarksville, OH, United States

Benz G.T.,Benz Technology International Inc.
Chemical Engineering Progress | Year: 2010

The rheology and suitable scale-up methods for agitating relatively new types of slurries, such as those containing lignocellulosic materials are presented. The use of either fed-batch or continuous-flow mixing avoids the need to agitate the original high-solids material, because the feed to the agitator is a liquid mixture of hydrolyzed material plus some of the unhydrolyzed material. The high-solids fibrous slurries can form a pile with a finite angle of repose that is associated with yield (shear) stress, and the shear stress must be exceeded before motion will occur. Fibrous slurries are two-phase systems that include a liquid carrier phase and a solid, fibrous phase. The carrier is typically a low-viscosity liquid such as water. The sometimes-high apparent viscosity results from the mechanical interactions among fibers as shear stress is imposed on the system in an attempt to make it flow. After a certain degree of reaction, the fibrous structure is lost, and an apparent viscosity can be determined with conventional viscometers. Source


Benz G.T.,Benz Technology International Inc. | Du L.,Terrace International Inc.
Chemical Engineering Progress | Year: 2010

Several factors that need to be considered by the companies when sourcing process equipments outside local channels are presented. Companies from developed countries are looking to developing countries and other sources outside well-established channels when purchasing relatively inexpensive capital equipment and materials. Some companies employ staff who are trained to address cultural and communications differences, or offer their employees language and culture training courses. Another option is to enlist the aid of a specialist with experience in international business and communications who can smooth the communication and ensure efficient results. The main reason of sourcing in developing countries is to reduce capital costs, long-term ROI depends on operating and maintenance costs, which are a function of equipment reliability. Companies need to take steps to verify that the potential supplier has the necessary capabilities and experience to produce a suitable product. Source


Benz G.T.,Benz Technology International Inc.
Chemical Engineering Progress | Year: 2010

Building a plant incurs several types of constructing and operating costs but capital and repair and operating expense (R&E) costs are significantly dependent on the size of the plant or the number of trains. It is recommended that plants should be built at the highest practical capacity for the foreseeable market, and with only one train to minimize total product cost but this concept is sometimes not acceptable. When the number of plants is to be built several factors other than lowest possible production cost must be considered such as transportation costs of raw materials and products, availability of customers and suppliers, local labor costs and seasonal concerns. Multiple trains would be necessary in a single plant if there is the need to make more than one product or if the process is prone to seasonal variations in material supply or product demand. A multiple-train design will certainly result in an increase in cost for all products. Source


Benz G.T.,Benz Technology International Inc.
Chemical Engineering Progress | Year: 2012

Agitator power consumption can be minimized by right equipment selection and careful operating procedures. Power requirements can be significantly lower for a large impeller especially for high viscous liquids. However, above impeller diameter/tank diameter values of 0.5 to 0.65 for hydrofoil impellers or above 0.45 for pitched blade turbines, flow patterns can become undesirable in low-viscosity fluids. Turning the agitator off after the contents are blended can save considerable energy. In applications where trace amounts of solids or slowly settling solids are present, intermittent agitation may be sufficient. For batch reactors with a low enthalpy of reaction, there is no need to run the agitator continuously. After initial blending, it may be possible to turn off the agitator or operate it intermittently to reduce energy consumption. In a continuous flow process at steady state conditions, the required agitator power remains constant. To save energy in these processes, the optimum gas flowrate for each liquid level and each stage in the process must be determined. Source


Benz G.T.,Benz Technology International Inc.
Chemical Engineering Progress | Year: 2012

Gregory T. Benz, P.E., from Benz Technology International, Inc., explains the way to determine torque requirements for multiple-impeller slurry-mixing systems to optimize tank geometry and minimize power consumption. He states that achieving complete fluid motion requires overcoming the yield stress everywhere in the tank. More torque needs to be provided by the bottom impeller than by upper impellers and failure to consider results in higher geometry and power requirements are affected by the torque split. It is necessary to overcome the yield stress of the slurry at the tank bottom and at the side wall to achieve mixing at the tank bottom. The torque needed from the bottom impeller to create complete motion is substantially more than that required of upper impellers, which need to overcome the yield stress at the sidewall. Source

Discover hidden collaborations