Series KP Presses
October 7, 1996, Revised October 2002 ISSUE #51
Vincent Corporation has introduced a new series of screw presses. These have been designed to serve two applications where light dewatering is required. In both applications free water is removed more thoroughly than can be achieved with conventional screening devices.
The broadest market for the KP presses is waste from canneries and food processing plants. In these facilities waste is normally sluiced to a collection pit from which it is pumped with a chopper pump. Static and vibratory screens are generally used to strain the waste water from the solids. The solids are then transported to landfills, or given to farmers for animal feed or landspreading.
The problem with this system is that water continues to drain from the solids after the screening. This results in dripping in the parking lot, citations for leaking wastewater on the highway, and loads that are rejected at the landfill because of excessive moisture content.
A conventional screw press is not suitable for dewatering this waste both because the cost of the press is excessive and because the press loses capacity and forces excessive solids into the wastewater stream.
The KP press, with three stages of compression instead of five, addresses these problems. It dewaters far better than a screen, yet it drives less suspended solids into the press liquor than a conventional press. Waste streams that have been successfully tested to date include: cull tomatoes, potato peel from peelers, egg shells at an egg breaker, spent brewers grain, trim material at a facility producing TV dinners, and out-of-date produce at a vegetable and fruit warehouse. One unusual application in this category involves pressing dairy manure to reduce load on the waste treatment lagoon.
The second market for the KP presses is in place of a screen ahead of a conventional screw press. This screening allows conventional presses to press tighter, with higher throughput capacities. It is expected that the KP press will be a significant improvement in this process.
Two applications where the KP press is used ahead of conventional presses are being tested: (1) thickening pumped corn waste materials at wet corn milling plants, and (2) thickening shredded citrus peel in plants that pump the peel to the feedmill. In describing the application we are referring to the KP as a pre-press, suitable for pre-thickening. In essence we are offering double pressing at a bargain capital cost.
The cost of manufacturing a KP press is approximately half of that of a comparable Model VP or CP press. Costs were reduced through a combination of several unique features:
The inlet hopper was simplified, eliminating the inlet screen.
The thrust bearing was eliminated by selecting gearboxes with suitable thrust carrying capacity.
The discharge cone was replaced with a simple discharge plate actuated by a 4-bar mechanism.
The screen covers, spreader bar, and collection pan were replaced with either a single piece of pipe or a pan and cover.
The press does not have a base frame; prior to operating the press the customer must anchor it to steelwork or other suitable foundation.
The value of the KP presses must not be underestimated. The construction is entirely of stainless steel; drive motors have half again the anticipated horsepower requirement, and the gearboxes have been selected for a twenty-year life expectancy.