Moisture Control in Fish Feed Dog Food

The main factors affecting the final moisture content of feed products are: the moisture content of the feed material itself, the moisture change in the crushing stage, the amount of liquid added in the mixing stage, the moisture content of the steam, the level of tempering, the die hole size and thickness of the die, Cooler air volume and drying time, packaging quality management, the influence of different climate and environmental factors, etc.

*Feed ingredient moisture control

1. The key to moisture control in the raw material receiving process is to accurately detect the moisture content in raw material samples. Sampling must represent the overall situation of the entire batch of raw materials. Samples should be taken according to sampling standards to prevent missed sampling. At the same time, sensory detection of raw material moisture in the sampling process high and low. In the process of raw material moisture detection, accuracy must be ensured. In order to reduce errors, two to three parallel samples can be tested, and the average value can be calculated as the detection value.

2. Do a good job in the management and storage of water-absorbing raw materials (rice bran, wheat bran, etc.)

Raw materials that are easy to absorb water do not need to be purchased too much at one time, and at the same time avoid stacking against the wall, pay attention to warehouse management, moisture-proof, and prevent moisture from entering the warehouse in humid weather. The raw materials should be imported according to the amount of raw materials under normal production conditions, and the raw materials should follow the "first in, first out" principle to shorten the storage period of raw materials as much as possible. After testing, the moisture in the storage is more than 10% cottonseed meal, and the moisture loss is about 1% after six months of storage.

*Moisture control in the crushing stage

The sieve of the pulverizer, the comparative detection and analysis of the moisture content of the material before and after pulverization found that as the particle size of the pulverized material decreases, the moisture loss increases significantly. Similarly, for materials with different gradient moisture content, the comparative detection and analysis of the moisture content of the material before and after crushing shows that with the increase of the moisture content of the material, the moisture loss of the powder after crushing increases, the maximum loss of moisture is close to 1%, and the crushing efficiency is significantly reduced. Energy consumption increases significantly. After the shrimp material is ultra-finely crushed, 98% of the particle size can pass 80 mesh. At present, the water drop type hammer mill is mostly used for fish feed, and the particle size of the screen is 1.0-1.5mm. For the pulverizer equipped with negative pressure suction and air door adjustment device, the air volume can be adjusted. A comparative test of the moisture loss of the material before and after crushing found that the air volume has a significant impact on the production efficiency, while the water loss has no significant impact, but with the increase of the air volume, the water loss still tends to increase. After the corn is crushed, the water loss by mechanical transportation is 0.22%, and the loss by pneumatic transportation is 0.95%. Most of the shrimp feed is ultra-fine grinding without net, which is transported by air suction. Most of the fish feed is crushed and then mechanically transported by auger.

*Moisture Control During Mixing

When the moisture content of the mixed powder is much lower than 12.5%, it may be considered to spray atomized water during mixing. But there are many problems in this aspect at present: it cannot exceed 2%; the water retention performance is poor, adding 2% water only has a water retention rate of 40-50%; it is best to use hot water to prevent mildew; the mixing time and water addition time should be considered (spray together) are consistent; in order to ensure uniformity, adjust the position of the nozzle and the size of the water nozzle; it is necessary to add antifungal agent; pay attention to cleaning the inner wall of the mixer.