Larger Nutsches are available in volumes including 10, 20, 30, 40, 50, 100, 200, and up to 1000 liters, plus any special volumes in between. “Typical” type units are offered providing a similar feature set as the Pope Benchtop series, but in addition, several design choices plus a very broad range of unique customization are available. 316L stainless steel construction is standard, other alloys, coatings and special finishes are available. ASME certification is standard, CE/PED and others also available.
There are many different types of customer’s applications, process requirements and preferences. Pope’s Nutsche applications professionals are on hand to assist clients with specification and quotation of optimized equipment. The starting point for this is our Nutsche Application Questionnaire. Sizing of units depends on the total slurry volume, the quantity of expected filter cake to be collected and other issues; Pope’s Nutsche Cake Depth Volume Chart is utilized in this determination. Other design considerations include:
Sanitary clamp type flanges can be utilized in even sizes up to 12” diameter vessels. The lower flange is a special variation which allows for holding and sealing a variety of filter screens and fabrics. Upper removable lids and flanges are available also. Beyond 12” diameters, heavy duty flanges and C-clamps are utilized.
The most basic vessel geometry is a single lower flange only. With this design, the entire body is raised up, or the bottom end is lowered from the body to harvest the filter cake. Another option is to also have a removable top head. This provides the user with two means of access and harvesting, removing either the top or the bottom head, or both. Some users prefer to have an additional flange for vessel break-apart a short distance or midway up from the bottom filter flange. This provides for containing of the filter cake when the upper section of the vessel is removed, and convenient cake harvesting without spillage. There are other variations including “removable basket” design. See photos for examples.
Nutsche vessels normally come with legs with locking castors. Depending on geometry, (see above) the number and location of legs may vary. With vessels larger than 8” diameter, the vessel sections can become heavy and inconvenient for manual movement and lifts are typically provided for safe raising/lowering and movement across rooms. Variations can include self contained lifts, platforms, and specialized frame for manual or automated rotation of vessel. See photos for examples.
In many cases, though not all, some means of agitation is required or preferred. Pope’s Series 700, 800 or 900 mixers are offered for conventional type stirring of slurry before or during filtration or after reslurrying. Raising/Lowering cake churning and smoothing agitators are also offered. These provide grater efficiency in braking up clumps and shortening drying time.
Vessel jacket heating is offered to help in drying the filter cake. Heated dry air or nitrogen can also be admitted at a fixed rate. These, in conjunction with vacuum and cake agitators optimize drying efficiency. Electric heaters are available as an alternate to liquid jackets
Multi layers stainless steel filter screens are available from 1 to 200 micron pore size. 50 micron filter are “standard”, covering a wide range of applications. In addition, polypropylene cloth and other special type membrane filters can be used. Pope’s designs provide customers with a choice and changing from one type to another without any further nutsche unit modification.
Many options are offered including sight glasses, valving, pressure and temperature indication/control, other sensors, sampling ports, spray head, and side discharge harvesting ports. Special skid mounted systems combining liquid and vacuum pumps, reactors, control systems and other turnkey features are also available.