April 7, 1999

There is a long established firm in Wisconsin that has found new applications for Vincent equipment. They produce dietary supplements and non-prescription drugs that have received a great deal of attention in recent years. The products are made from vegetables and meat organs. The firm operates a farm to grow their own organic crops. Located nearby is their laboratory, a large facility with intense sanitation and quality control standards.

About two years ago a VP-12 screw press was installed at the farm. It is used to extract juices from plants such as alfalfa, beans and buckwheat. These juices are further processed at the laboratory.

Recently excellent success has been achieved with a small FF-6 Fiber Filter. It is being used on meat products at the laboratory.

The meat products are based on enzymes. These are extracted from animal organs such as veal bone, ovaries, adrenal glands, testicles, heart muscle, eyes, and thymus gland. About thirty different products are available.

The process of extracting the enzymes begins with shredding the meat to a hamburger-like consistency. This is soaked for twenty-four hours in 2,000 gallon tanks containing salt water. The saline solution allows the enzymes to pass through the cell walls. After the soak period the meat must be separated away from the solution.

The filtration is accomplished by pumping the material through the Fiber Filter. Rates ranging from 8 to 40 gpm are achieved. Previously this filtration was all done in an Alfa Laval centrifuge. Mostly because of blinding by the fat content, the process had been slow. To our surprise it has been found that, with the right rotor design and fabric sleeve selection, blinding by the fat has been controllable in the Fiber Filter. With some products the Fiber Filter spray/wash system must be operated every 10 minutes or so, while with others runs of an hour are possible. Flushing is performed with filtrate, eliminating dilution.

The sludge cake from the Fiber Filter can range from rather firm "ground meat" to a stream of greasy water. Overall the filtrate has improved on several products. A few products, such as parotid (salivary) glands, run better in the centrifuge than in the Fiber Filter. In most cases the Fiber Filter operates at higher throughputs than the centrifuge.

In general the Fiber Filter is operated at a rather steep angle, close to 30º. When the cake sludge tends to be too soupy, indicating a lower yield, adjustments are made. To thicken the discharge cake, the inclination angle of the rotor can be increased, the inbound flow can be reduced, or the spray/flush system can be operated.

Coarser mesh sleeves in the Fiber Filter result in higher capacity, generally with acceptable solids content in the filtrate. Fine mesh sleeves are used for very dilute solutions.

The filtrate from the Fiber Filter requires considerable additional filtration. Most products are pumped through bag filters, then to a scraped plate heat exchanger that works with an ammonia chiller. Ice crystals form in the heat exchanger; these are removed in a TEMA centrifuge. The filtrate from this centrifuge goes through a membrane ultra filtration machine before being concentrated in an evaporator. The concentrated liquors from the evaporator are dried and then made into dietary supplement tablets.

A new area of business diversification for the firm is the introduction of products designed for household pets.

Success with the meat products has encouraged Vincent to seek testing on wastewater at slaughterhouses and other meat processing facilities.

Issue 92