Pfeuffer GmbH
Sampling and measurement, Kitzingen, Lower Franconia, Bavaria, Germany.
History
Pfeuffer was born in 1947, and not as a manufacturer. Franz Pfeuffer, a mill-building engineer, opens in Tiefenstockheim, in Lower Franconia, a consulting and design office serving flour mills. Advising a miller means measuring what he grinds. From this come, in the 1950s and 1960s, a dough volume recorder, which tracks the rise and so judges the flour. Added to these are rapid drying ovens and electric moisture meters, those instruments that read the water in the grain through an electrical property. In the early 1970s comes a laboratory sorter. In 1976, Franz hands over to his son Klaus and daughter-in-law Rosemarie. The turning point is 1981: they set the company up in Kitzingen and change its nature. The design office becomes a development and production company, meaning it finally sells machines. The third generation, Frank-J. and Lothar Pfeuffer, joins management in 2000 and pushes sales abroad. A first ISO 9001 certificate follows in 2001, which covers work organization and not products. In 2003 comes an ATEX certification, the one aimed at equipment intended for explosive atmospheres. It counts here: grain dust explodes, and these machines work in silos. In 2006, Pfeuffer Holding buys the sampling branch of the Danish Rationel Kornservice A/S, in Esbjerg. That is how the Rakoraf truck samplers enter the catalog. An assembly hall of 1,000 square meters houses the two productions combined in 2007. The Danish activity is then fully integrated into Kitzingen's processes, between 2008 and 2011. A new building for manufacturing, administration and development is made weathertight in 2015. The company celebrates its seventieth anniversary in 2017. It employs forty-five people on about 4,500 square meters, which explains a narrow catalog without a roaster.
What it makes
The company builds no roaster. It makes the sampler in the strict sense, the hollow probe pushed into a pile to draw a sample. The principle is a tube within a tube. Both walls are slotted, and the probe enters the product closed. A rotation of the handle aligns the slots, the chambers fill, a reverse rotation closes them. The manual probe is made of two anodized aluminum tubes that come apart, because a residue from the day before skews today's sample. On the PNS probe, the openings open in a spiral, from bottom to top, so that the product does not fall first into the upper chambers. The sample comes out at the back of the handle. The Rakoraf motorizes this gesture: a probe carried by an arm plunges into the bed of a truck. Transfer takes place through the Convac system, presented as patented, which applies no suction to the load. The air picks up only what has already entered the probe, then conveys it through a pipe to a separator, in the laboratory. The DVB samples a moving stream, in a downpipe. A small cassette hopper, slotted on top, crosses the product across the whole width of the tube, and not at its edge. The rest of the catalog prepares the sample, with dividers and sieve-and-suction cleaners.
The models
No model is counted in kilos per batch: the company roasts nothing, it samples. Pfeuffer manual probes, in anodized aluminum: 1.50 m, 40 mm in diameter, six openings, 1.8 kg, 600 g of sample, reference 1720 0500. The second is 2.00 m, eight openings and 2.3 kg, yields 800 g, reference 1720 0510, and samples down to 2 m deep. PNS probes in alloy version: PNS84 of 1.45 m and 2.0 kg, PNS88 of 2.00 m, 2.50 m and 3.00 m, from 2.5 to 3.5 kg. All are 38 mm in diameter and yield 400 to 600 g. A pellet version measures 1.30 m by 50 mm and weighs 2.3 kg. Rakoraf CEE truck sampler: 2.1 m probe as standard, options of 2.3 m, 2.5 m and 3.0 m. It rotates about 350 degrees, covers a ring of 4.8 to 8.8 m in diameter and weighs 475 kg. Its power supply is 3 x 400 V, 50 Hz, 10 A, for 4,000 VA. The Rakoraf 2 is fixed, with a maximum radius of 4.4 m. The Rakoraf 2 LINEAR, mounted on lateral travel, covers an area of 8.8 by 18.8 m. DVB 200 stream sampler, for a 50 mm downpipe, 0.09 kW, 36 kg. The DVB 300 targets a 76 mm tube, for 0.16 kW and 85 kg. Both exist in ATEX version, with interchangeable slots, from 8 to 14 mm on the 200, from 12 to 30 mm on the 300. Vario 1G, 2H and 4/8 dividers, with continuously adjustable division ratio, 230 V, 60 W, from 60 to 72 kg. They yield respectively one, two, then four or eight subsamples. MLN and SLN sample cleaners. The MLN runs on 230 V, 0.37 kW, 55 kg, with a straw sieve of 4.5 by 20 mm and a sand sieve of 1.5 by 3.5 mm.
What you gain
The probe takes a volume, not an air stream. The Convac does not pull on the load: the air carries only what is already enclosed in the tube. The proportion of broken beans and fines therefore remains that of the pile, whereas direct suction enriches the sample in light elements. The spiral opening serves the same end: each chamber fills at its own depth, and the sample keeps the stratification of the load. A 2 m probe yields 800 g in a single motion. The shape of the openings avoids crushing the bean, so the measurement of broken beans remains that of the lot.
What you lose
A probe cannot see farther than its length: 2 m on the standard model, 3 m at most. Under a deeper load, an entire layer escapes sampling. This is the bottom layer, where fines and moisture concentrate. The Rakoraf is a fixed station: 475 kg, three-phase 400 V, 4 kVA, a ring of 4.8 to 8.8 m. It samples the trucks that come to it, nothing else. The catalog is sized for bulk grain, with tubes of 38 to 40 mm at least 1.45 m long. A coffee sampling probe, on the other hand, works on a jute sack.