Pinpointing possible grain problems
Understanding the quality and condition of grain is crucial, and the only way to assess that is through accurate sampling at each stage of the grain chain.
Accurate sampling can help to reduce waste and minimise charges, claims, and rejections. As commonly practiced, sampling involves the collection of physical grain, so it can be tested for moisture, temperature, and possible contamination by pests and moulds.
For many years, sampling grain has been important in measuring key quality parameters in combinable crops (e.g. Hagberg Falling Number, nitrogen content and specific weight). In recent years, however, other challenges (including Mycotoxins) have emerged, requiring the industry to demonstrate due diligence. Providing grain samples is part of that evidence. Grain sampling is, therefore, even more important and must be undertaken using appropriate methods at the most relevant points along the grain chain.
Under the current system typically employed in the United States, when a grain truck pulls up to an elevator, the tarp covering the grain is pulled aside and a six-to-10-feet long probe is thrust into the grain. A chamber inside the probe takes in a sample, which is then tested. Sometimes this sample is manually extracted. At other facilities an automated probe pneumatically takes a sample. But the sample is limited to the loading/offloading process and does not answer the problem of how to test the great depth and quantity of grain being held in a grain bin or silo.
The Port-A-Probe system
At the recent GEAPS (Grain Elevator and Processing Systems) show held in Denver, Colorado, March 23-27th, 2018, among the many companies exhibiting was Port-A-Probe, of Prairie Village, Kansas, USA. The company"s motto is "Sampling is better than gambling," and the company has backed up that claim by investing years of development in a portable grain sampling system. We sat down with Janet Rickel, the company"s Marketing Manager, to learn more about the Port-A-Probe and discover what advantages it brings to grain producers and distributors.
"The Port-A-Probe system is basically a positive displacement vacuum pump mounted on a two-wheel cart/frame," Ms Rickel explained. "The pump intake air is cleaned by a Cartridge dust filter and a Wye Strainer [a device for mechanically removing unwanted solids from liquid, gas or steam lines by means of a perforated or wire mesh straining element, and is typically used in pipelines to protect pumps, meters, control valves, steam traps, regulators and other process equipment].
The frame-mounted Port-A-Probe can be trailered behind a vehicle or mounted on the bed of a pickup truck. Alternately, it can be disconnected from the frame and moved to a remote location such as a gallery work floor.
"Our largest unit sits in the bed of a pickup truck," Ms Rickel said. "The vacuum pump is connected to a metal probe via a hose that can be in excess of 400 feet long (122 metres). The hose is connected to a metal probe consisting of sections made up of four feet long (1.21 metres) high tensile aluminium pipe fitted with a replaceable four inch long (10 mm) machine threaded aluminium intake tip. The probe sections are also machine threaded and can be screwed together to create a custom-length probe to suit the depth and dimension of the grain silo being sampled."
Extracting a sample
With the probe assembled to the required length, the vacuum pump is first set to blow out rather than suck in. This helps move grain out of the way as the probe in pushed deeper into the grain held inside the silo. Depending upon the type of grain, the probe usually requires a single operator riding on a cherry picker (aerial work platform) or similar to access the silo from the top, at which point the probe can be manually pushed down into the grain.
Once the probe is inserted to the desired depth and location, vacuum is applied which draws up a discrete sample of grain that is collected in a plastic pitcher. The sample can then be analysed and appropriate action taken if problems are found with the grain.
The advantages of pinpoint probing
The Port-A-Probe allows the extraction of grain samples with pinpoint accuracy. "Depending upon the type of grain," Ms Rickel continued, "the Port-A-Probe can go deeper than almost any other type of probe—often as deep as 120 to 140 feet [36 to 42 metres]. Plus you can move the probe around the silo to take fresh samples from various depths and locations."
Importantly, this solution means that samples are taken when the grain is not moving and where its identity is preserved. Moreover, the use of pinpoint probing avoids turning the grain, a procedure that often damages the grain. "Turning the grain can be problematic," Ms Rickel added, "since turning the grain does not allow users to pinpoint the location of the sample. You don"t know from where in the silo the sample came from, plus you invariably mix the bad grain with the good.
And also, there"s the energy costs involved with turning the grain."
With the Port-A-Probe, a grain sample is drawn up by the probe and then passed through a filter and into a collection pitcher. The sample is then placed in a bag, marked, and sent on for further testing. "It gives you a better idea of what"s going on in the depths of the grain silo," Ms Rickel said. "We have a lot of grain that"s in storage for three to five years. There could be moisture build up, bugs, or disease. Using our probe. you can go down as deep as 120 to 140 feet [36 to 42 metres] and sample from all around the edges of the bin and all the way from the bottom to the top of the bin."
The Port-A-Probe system is available in a variety of models which use electric-start Honda petrol (gasoline) engines ranging from 5.5 HP to 9HP (4 to 6.6 kw). The 9HES model, for example, is designed for heavy-duty commercial use. It can sample grain silos that exceed 120 feet in height (36.5 metres), as well as large flat storage structures and grain piles.
The company"s D&D Vac (Dust and Debris Vacuum Cleaning system) is designed to be used with the Port-A-Probe. A Cyclone Receiver connects to a modified drum lid and discharges into a 30-gallon (113 litres) high strength drum. In another application, the system can be fitted with a larger probe tip and used to deliver fumigation pellets to precise locations within the silo. This means only the contaminated section of grain need be fumigated, rather than the entire silo.
While most users of the Port-A-Probe tend to be small farms or feed companies, the portable nature of the equipment makes it ideal for use in ports to sample grain held in the holds of ships.
An expanding user-base
Port-A-Probe is a genuine family business. The units were designed by Ms Rickel"s late father. Her sister handles the paperwork and day-to-day running of the business, while Ms Rickel is the marketing manager. They are currently selling 10 to 15 machines a year to countries including the United States, Canada, China and Mexico.
by Vaughn Entwistle, Features Editor, Milling and Grain