FIELD OF INVENTION

The disclosures made herein relate generally to accurate and automatic programmable Logic Controlled chemical handling and dosing system.

BACKGROUND OF THE INVENTION

It's very critical and important to weigh and mix all chemicals, water and other ingredients in appropriate quantity in any of the food processing or chemical industry operations. To maintain a uniform and high quality final product it is imperative that the ingredients be mixed in a fixed proportion. In case of manual dosing and mixing of ingredients it becomes extremely difficult to maintain the consistency of the product. An automatic logic controlled dosing and mixing system can however is much more fast, reliable and independent.

There have been a variety of different types and kinds of apparatus, system and methods for mixing ingredients. For example, reference may be made to the following are- According to United States Patent Application 20080172141 / WO/2007/008767 wherein A system and method of formulating a batch comprising at least two ingredients. The ingredients are admitted to a container to partially fill it (28). The quantities of the ingredient in the container are determined (30), and a ratio of a target quantity to the determined current quantity for at least one ingredient is calculated (32). The next quantity of that ingredient to be admitted to the admixture is calculated by multiplying the target quantity by the calculated ratio to determine a corrected quantity (34). The corrected quantity of the ingredient is admitted to the admixture (36), and a quantity of another ingredient is admitted to the admixture to adjust the proportion of ingredients to the target formulation (38). These steps may be repeated until the batch is completed. According to Patent 5423455 wherein an improved system and method for gravimetrically feeding material at a controlled rate. The material to be fed, which can be either a dry solid or a liquid, is maintained in a supply vessel. A probe disposed in the supply vessel detects the level of the material, sending a high level signal to a controller. A scale weighs the material in the supply vessel, sending a weight signal to the controller. The controller then calculates the density of the material in the supply vessel based on the weight and density of the material. The calculated density is used to affect the feed rate to achieve an operator-input set rate. During refill of the supply vessel, the probe detects material at a high level, sending a signal to the controller which, in turn, sends a signal to a refill valve, stopping refill.

According to United States Patent Application 20100146587 /WO/2010/067303 wherein Authentication of products dispensed in an automated chemical dispensing system occurs via electronic communication of product information. The dispensing system includes a plurality of dispense stations, each of which is configured to dispense a corresponding specified chemical product. A product container includes an electronically readable label or tag that includes product information that identifies the chemical product in the container. A product dispenser reads the product information and automatically determines whether the specified product has been loaded onto or into the dispense station. If the product is thus "authenticated," the system may permit dispensing of the chemical product. If the product is not authenticated, the system may prevent dispensing of the chemical product and/or generate an error message.

According to United States Patent 4402426 wherein Food is fed onto a weighing platform inside a dispensing chamber and carried by a parallelogram weighing support disposed outside the dispensing chamber and supported by four parallelogram arms from an upright frame, the platform being retained in a position to receive the food by a releasable electrically operated latch. When a weigh beam detects a weight set by a control circuit, it sends an electrical signal to the control circuit which causes feed to stop and provides a condition in which an electrical signal can be sent to the latch to release the weighing platform into a position in which a weighed portion of food can be discharged therefrom. In one embodiment, at least one switch is manually operated from outside the unit to cause the control circuit to apply the releasing signal to the latch either immediately or after an interval of time.

SUMMARY OF THE INVENTION

This invention relates to Chemical handling and dosing system by programmable Logic Control System.

Further object of the invention is to achieved is ± 10 Grams over 5 Kg without human error and even human presence and High Productivity achievement.

The details of one or more embodiments of the inventions are set forth in the description below. Other features, objects and advantages of the inventions will be apparent from the description.

DETAILED DESCRIPTION OF DRAWING

Figure 1 - P & I Diagram of chemical handling system

The system basically consists of ingredient feeders, PLC sensors and actuators, conditioning chamber and inline mixers. The feeders are widely used hoppers which are used to store and feed the raw ingredients to the conditioning chamber. Each feeder is fitted with a pneumatic/ electrical/ hydraulic operated actuator which is connected to the programmable logic control via load cell sensor. The feeders are connected to the preliminary conditioning chamber where the weighment is done. Required temperature and weight of the water is attained by checking temperature of (a) hot water (b) ambient water (c) chilled water and mixing it in right proportion calculated by the PLC. On attaining the right temperature and weight pre weighed chemicals are dumped and high speed agitator is started. Chemical dumping sequence is also followed. On mixing of for fixed time solution is pressure transferred via mechanical filter into any of the mixers. Oil and moisture free compressed air is used for transfer. All sequences are controlled by PLC and are automate DETAILED DESCRIPTION OF INVENTION

Accordingly, in one aspect, this invention is based on automatic, highly accurate and consistent ingredient dosing and handling system operated by a programmable logic control (PLC). The system finds application in food, confectionery, rubber, lube oil, paint manufacturing and pharmaceutical industry with special application to the bakery industry. The system is highly accurate and requires minimum human intervention and thus significantly reduces the operating cost of the system. An automatic logic controlled dosing and mixing system can however is much more fast, reliable and independent. The equipments and part of the system is capable of handling commonly used chemicals in the above mentioned industries. As in a particular case of bakery industry the system is capable of handling varying amounts of ingredients such as leavening agents, dough powder, water, dough improver, dough relaxer, dough conditioners, sugar thereof.

The chemicals are loaded in respective hoppers (refer diagram 1) in bulk during the production operation. The PLC controlled pneumatic/ electrical/ hydraulic actuators and sensor controls the outlet from each hopper and thereby controls the amount of chemical to be released in the conditioning chamber. The PLC can be programmed in advance to release particular amount of each ingredient in each mixing cycle. Also the PLC system also indicate the amount of ingredient currently left in the ingredient hoppers and also generate a warning in case the level of ingredients falls below a certain pre defined limit. From the conditioner chamber the PLC also controls the amount and timing of the amount to be dispatched to each of the inline mixers.

Programmable logic controller (PLC) or programmable controller

A programmable logic controller (PLC) or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines. We are using Programmable logic controller (PLC) because PLCs are armored for severe conditions (such as dust, moisture, heat, cold) and have the facility for extensive input/output (I/O) arrangements according to requirement. These connect the PLC to sensors and actuators. PLCs read limit switches, analog process variables (such as temperature and pressure), and the positions of complex positioning systems. PLCs operate electric motors, pneumatic or hydraulic cylinders, magnetic relays, solenoids, or analog outputs. The input/output arrangements may be built into a simple PLC, or the PLC may have external I/O modules attached to a computer network that plugs into the PLC.

Programming: In the primary stage of PLC programs are typically written in a special application on a personal computer. This can supply programmed quantity of each of the chemicals and the solvent into a mixture. Human error free system operates without human presence after loading chemicals into the respective feeders.

Operation: On demand from any of the process centers the chemical mixture is pneumatically dispensed. PLC is programmed for Different ratios of Chemicals for different Recipes. Then downloaded by a direct-connection cable or over a network to the PLC. The program is stored in the PLC either in battery-backed-up RAM or some other non-volatile flash memory. Often, a single PLC can be programmed to replace thousands of relays that is also a additional point. PLCs are well-adapted to a range of automation tasks. One single system serves multiple Process Centers and dosing quantity is as per the programmed recipe at each of the process centers. By PLC can be control to very complex process, such as used in the chemical industry, may require algorithms and performance. Very high-speed or precision controls may also require customized solutions. It gives highly accurate result as compared to others.

Accuracy: Accuracy achieved is ± 10 Grams over 5 Kg. Very high Dosing accuracy is achieved, thereby maintaining Consistent Product Quality. The system eliminates human error and even human presence. It saves in Manpower and High Productivity achievement. The commonly used chemicals in the bakery industry that can be easily handled by the system with bried description are as follows:

Leavening agents- They are vital ingredients for virtually any bakery product. It causes a foaming action which lightens and softens the finished product. The leavening agent incorporates gas bubbles into the dough— this may be air incorporated by mechanical means, but usually it is carbon dioxide produced by biological agents, or by chemical agents reacting with moisture, heat, acidity, or other triggers. When a dough or batter is mixed, the starch in the flour mixes with the water in the dough to form a matrix (often supported further by proteins like gluten or other polysaccharides like pentosans or xanthan gum), then gelatinizes and "sets"; the holes left by the gas bubbles remain. Example - Ammonium carbonate, Monocalcium Phosphate Monohydrate, Sodium Acid Pyrophosphate, Sodium Acid Pyrophosphate thereof.

Ammonium carbonate is used as a leavening agent in particular recipes, It can sometimes be substituted with baking powder, but the finished product will never be as airy and light as the original recipe. Especially air biscuits for instance simply cannot be made with anything other than ammonium carbonate.

Some typical biological leaveners are:

Beer (unpasteurised— live yeast

Buttermilk

Ginger beer

Kefir

Sourdough starter

Yeast

Yogurt

Chemical leavening agents include:

Baking powder

Baking soda (sodium bicarbonate)

Monocalcium phosphate

Sodium aluminum phosphate (SALP)

Sodium acid pyrophosphate (SAPP)

Other phosphates

Ammonium bicarbonate (hartshorn, horn salt, baker's ammonia)

Potassium bicarbonate (potash)

Potassium bitartrate (cream of tartar)

Potassium carbonates (pearlash)

Hydrogen peroxide

Dough Consistency Powder

The prominent features of Dough Consistency Powder are following- Stops flowing water immediately

Sets fast, in one to two minutes

Easy to mix and apply

Will set up and harden under water.

Dough improver

Dough improvers (dough conditioners) enhance the texture, firmness, water-holding capacity, appearance, shelf life, and other vital characteristics of a wide range of bakery products.

Dough relaxer

A dough relaxer is used to make the dough starch more without snapping back or shrinking in the oven. Relaxers are acid cased such as vinegar or lemon juice will work as well as cream of tartar. Dough conditioners

To give the baker more control over the baking process, some additives are used to change the dough in certain ways. Some of these dough conditioners are:

Sodium stearoyl lactylate

Calcium dioxide

Calcium iodate

Potassium iodate

Ammonium sulfate

Yeast nutrient.

Potassium per sulfate

Strong oxidizer. Used as a strengthening agent.

Ammonium per sulfate

Strong oxidizer. Used as a strengthening agent.

Calcium sulfate

Ascorbic acid

Amylase

Azodicarbonamide Nacl

It enhances flavor. Salt also has a chemical role. In dough and pastry it enhances texture as well. Salt has several functions in baked goods:

It contributes to overall flavor.

In bread, it controls the fermentation rate of yeast.

It has a strengthening effect on the gluten protein in the dough.

Without salt, bread rises faster and air pockets enlarge where the gluten has broken, allowing holes to form. Bread made without salt will taste bland. If you choose to eliminate salt, decrease the proofing time so that the large air pockets don't have time to develop. Salt should not be eliminated from recipes using automatic bread-making machines. Salt slows down all the chemical reactions that are happening in the dough, including calming fermentation activity to a steadier level.

Salt also makes the dough a little stronger and tighter.

Salt impacts the shelf life of baked goods, but its effects depend on weather conditions. Salt is hydroscopic, which means it absorbs water. Consequently, in humid climates, it will trap moisture from the air, making a crisp crust soggy, and therefore shortening shelf life. In dry climates, however, the salt helps hold water in the bread longer, inhibiting staling, and thus extending the bread's shelf life.

Salt, of course, adds flavor to baked goods. It also potentates the flavor of other ingredients, including butter and flour.

Sodium bicarbonate (NaHC03)

Sodium bicarbonate is primarily used in cooking (baking) where it reacts with other components to release carbon dioxide, which helps dough rise. The acidic compounds that induce this reaction include phosphates, cream of tartar, lemon juice, yogurt, buttermilk, cocoa, vinegar, etc. Sodium bicarbonate can be substituted for baking powder provided sufficient acid reagent is also added to the recipe. Many forms of baking powder contain sodium bicarbonate combined with one or more acidic phosphates (especially good) or cream of tartar. Thermal decomposition causes sodium bicarbonate alone to act as a raising agent by releasing carbon dioxide at baking temperatures. The carbon dioxide production starts at temperatures above 80 C. The mixture for cakes using this method can be allowed to stand before baking without any premature release of carbon dioxide.

Ammonium bicarbonate (NH4)2C03

Ammonium bicarbonate is used when crushed as a smelling salt. The modern leavening agents are baking soda and baking powder. It can sometimes be substituted with baking powder. Air biscuits for instance simply cannot be made with anything other than ammonium carbonate.