Rhodimet® AT88 equipment designing: DIM (Design Implement Monitor) good practices

Designing of liquid OH-Methionine application equipment in a feed mill starts with Customer’s needs assessment

Overall, even if all feed mills in the world share the main principles of the manufacturing diagram stages (raw material reception and storage, dosage, grinding, mixing, pelleting…etc.), they are all different.

Indeed, during the feasibility visit (first step of the project), Adisseo technologist takes into consideration many criteria: current and future volume of production, types of feed, number of mixing lines to be equipped, existing liquid equipment, space availability…

Climatic conditions, quality standards, preferences in term of dosage principle (flow meter or weighing scale) also varies lot from a region to another.

Moreover, the yearly estimated consumption of OH-methionine determines significantly the mode of delivery and storage (IBC, bulk) and at the end of the day the envelop of the investment.

What are the expectations towards a liquid OH-Methionine distribution equipment supplier?

Adisseo wants to provide to his customers not machines but a SOLUTION that works (in terms of safety, quality, reliability and cost).

To reach this goal, the equipment supplier should be experienced (or even specialized!) in liquid application AND in the feed industry. It should be reliable and financially solid. Such companies are not so common over the world.

It should propose good quality parts and propose perfect assembly and interface with the existing process.

The supplier must commit to obtain good results on the product application and feed quality (conformity, homogeneity). Part of the payment (10%) might be conditioned to the commissioning visit.

The quotation should be:

• Done in a reasonable delay (about 2 to 3 weeks maximum after the request);

• Understandable by the customer (English and/or local language) and detailed i.e. containing at least:

  • Date / Reference / Customer

  • Sections / Technical description / Scheme and plan of the installation (optional pictures)

  • Exclusions / Warranty / Validity of the offer / Delivery time

  • Price, Incoterms

Once the quotation is accepted and the goods well arrived, the installation can start! The delay between reception and works start should be agreed in advance with the customer and should not exceed 2 months.

SAFETY being the number one priority, the supplier must respect different safety rules, linked to: works and assembly, the product, internal rules of the mill and local regulation.

The installation should disturb the production as little as possible, especially during positioning the nozzles on the mixer and during the testing phase.
At this early stage, the supplier team is requested to train the feed mill staff on usage and maintenance of the equipment.

Then, considering the after sales services, the company should commit on the following points:

• Warranty of the equipment (1-year minimum).

• Ability to perform preventive maintenance visits. Having a local representative will be appreciated.

• Distance (phone) or direct support and spare parts supply within short delay in case of troubleshooting.

• Proper reporting for each customer intervention.

Guidelines for Unloading and Storage of liquid OH-Methionine in the feed mill

The choice on the storage type mainly depends on the consumption (tons per month) and local logistic conditions of liquid OH-Methionine. This product can be delivered in 1 m³ IBC (1,200 kg). IBCs can be used as such or transferred for intermediate bulk storage. For higher consumption, the product would be directly delivered in bulk.

In this case, the inlet should be well labelled and locked, mechanically and/or with automated valve.

A panel with safety labels will warn the drivers and plant staff. The installation of a safety shower is recommended.

If locally the trucks are not equipped with a pump, an unloading pump must be present at the plant.

It should be placed below the product outlet to facilitate the transfer. Its capacity should be oversized to consider the product viscosity, about 60 to 100 m³/h.

One or more bulk tanks will be installed, generally close to other liquid ones.

This is to benefit from the existing retention pool (refer to local regulation in term of environment).

The minimum storage capacity is calculated by summing the minimum stock and the quantity of one delivery, basically at least 30-35 m³.

The tank will include: a top and near bottom for service and inspection, a manhole for inspection, vent pipe, levels (mechanical, electronic).

Outside, it will be equipped with a caged ladder and fence for safe inspection and maintenance operations.

Conception and construction of the storage should avoid external contamination of the product (with dust, rain…). For extreme cold regions, avoid exposure to dominant winds if possible.

Heating of the main storage is not needed in general, but insulation may be recommended in cold regions.

The discharge point must be located on the bottom, not on the side, to avoid having a dead zone and retention of product.

Guidelines for Transfer and intermediate storage & heating of liquid OH-Methionine in the feed mill

An intermediate storage of liquid OH-Methionine located inside the plant is recommended in two cases: when warming up the product is needed (>15°C for proper viscosity for spraying) and/or when more than one mixer needs to be fed. This daily tank (1 to 2 m³) may be heated thanks to circulation of thermal oil in a double jacket, this oil being heated with thermal resistances.

For piping connections, welding or press-fitting are preferable. Proper supporting will prevent from excessive mechanical stress and vibrations which could lead to leakages.

For cold environments, pipes will be insulated and, optionally surrounded by self-regulating heating cables.
Sets of manual valves will be installed before and after the main components (pumps, flow meters, electro-valves) to allow easy replacement or maintenance.

To prevent the pumps from running dry, product sensors must be installed before them. Moreover, to protect them (and the flow meters), a Y-type filter must be implemented right before.

Guidelines for proportioning and dosage of liquid OH-Methionine in the feed mill

The scale system has the same principle as for solid dosage. In general, the liquid flows by gravity from a storage located above through a valve to the weighted liquid bin. This dosage bin can also be fed thanks to a transfer/dosage pump. As for any scale, its volume must be adapted to the quantities to be dosed and the load cells must have the expected accuracy (about 0.5-1% maximum of the minimum quantity).

The scale can be emptied by compressed air, or much more ideally with a dosing pump.

This dosing pump should be adapted to viscous products. Gear or screw type pumps generally fit well. Its capacity (liters/hours) should be calculated according to the targeted flow of injection in the mixer, and even oversized (rotation speed may be reduced to increase the life time).

It should include a pressure loop, safety valve and pressure adjustment.

The flow meter, whatever its type (mechanical, electromagnetic or mass), must be located close to the mixer, with easy and direct access.

A calibration valve must be located just after the flow meter to enable the verification of the dosed quantity.

Guidelines for spraying liquid OH-Methionine in the feed mixer

The spraying step is the most important one regarding proper application and homogeneity of the OH-methionine into the feed. Ensuring proper spraying means: obtain the right size of droplets, have sufficient spraying time, spray directly on the feed, avoid dripping and blockage of the nozzles. The spraying pressure is of high importance and should be between 3 to 5 bars in general.

The way to obtain these results is to select:

• the right type of nozzles: flatbed-jet is generally the most suitable pattern.

• the right number and size of nozzles: it is recommended to apply the liquid additive on the entire width of the mixer. To do so, the angle of the spray and the distance between the nozzles and the surface of the feed must be considered.

• their proper location on the mixer: not to spray on the sides, on the shaft or on the paddles but also to avoid overlapping of liquid sprays.

Placing an electro valve before each nozzle can be an option if there is a risk of dripping and if it is needed to make vary the number of injection points (when quantities can vary a lot from a batch to another).

Air flush of the manifold is a possibility to prevent the nozzles from dripping or clogging.

Commissioning of liquid OH-Methionine application equipment at the feed mill

Compliance with all good practices must result in an installation of liquid OH-Methionine application system at the required quality level. But the feed manufacturer, or a third party, must imperatively commission it.

This step should answer 3 questions:

• Is the equipment conform to the order?

  This is done through a precise comparison between what is installed and the terms of the order (or quote that served).

• Is it made according to the state of the art?

  This point requires a certain level of expertise in the field of liquids and may require external help. The absence of leaks, even slight, is an imperative condition.

• Is it working properly?

  During the test phase, one will check the proper computer and mechanical operation of the installation. The initial control of dosage accuracy will be done through the calibration valve. Visual inspection of feed samples taken right after the mixer will ensure the absence of lumps that can express spraying problems.

The last validation step is the conformity and homogeneity test. This “Mixer Profile” service may be offered by Adisseo to its customers.

Adisseo’s teams also offer other numerous services for the management of new projects (through the DIM program: Dimension, Implement, Monitor).