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Design and Development of Bottle Washer Machine for Small Scale Beverage Industry Conference Paper · March 2015 DOI: 10.1109/ICACEA.2015.7164724

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3 authors, including: Ankur Gajjar

Alpesh Patel

Shantilal Shah Engineering College

Nirma University

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2015 International Conference on Advances in Computer Engineering and Applications (ICACEA) IMS Engineering College, Ghaziabad, India

Design and Development of Bottle Washer Machine for Small Scale Beverage Industry Ankur G. Gajjar

Alpesh I. Patel

Raviprakash G. Singh

Research Scholar Control & Automation Institute of Technology Nirma University, Ahmedabad, India [email protected]

Assistant Professor Instrumentation & Control Engineering Institute of Technology Nirma University, Ahmedabad, India [email protected]

Assistant Manager Bussiness Development KHS Machinery Pvt. Ltd. Ahmedabad, India [email protected]

The bottle washer machine is a prominent part of the bottle filling and packaging line and it is used in the beginning of the bottle filling and packaging line. The bottle washer machine is mainly used to clean the used bottles in case of RGBs and it is used to rinse the bottles in case of PET bottles before the beverage filling and packaging is carried out. The functionalities of the bottle washer machine will be different based on the type of beverage container used.

Abstract— The conventional bottle washer machines are suitable only for medium scale and large scale beverage industry due to their high bottle washing capacity and mechanical and control complexity. This paper proposes the design and automation of the economical bottle washer machine for the small scale beverage industry without compromising its control capabilities. The importance and requirement of the bottle washer machine in the beverage industry has been discussed. The design of the proposed bottle washer machine for RGBs (Returnable Glass Bottles) has been created in the Creo software. The different treatment zones and working of the bottle washer machine has been discussed. The bottle washer machine has been automatized using the Siemens S7-317-2-PN/DP PLC (Programmable Logic Controller) and programmed using a ladder diagram in the SIMATIC Manager. The level control for different treatment zones is achieved by means of limit switches and temperature control for different treatment zones is achieved by using Pt1000 RTD, SSR (Solid State Relay) and heater. The different control schemes for the temperature control has been discussed, implemented and compared. The results show that the PID temperature control is the most effective control scheme for the temperature control of the different treatment zones. The implementation of the PID temperature control and auto-tuning of the sample process has been shown. The holistic control of the bottle washer machine also has been discussed and assessed.

The used RGBs need to be cleaned before beverage filling and packaging is carried out since used bottles may contain dust, sand, beverage residues, rain water, mineral stains and microbes [1]. Microbiological spoilage due to microbes leads to degradation of the sensory quality and commonly appears as off-flavors, odors and visual changes in the beverage [2]. It may also lead to change in pH, gas formation in the beverage and may result in a haze, precipitation or intoxication to the user [1]. The common microbes which leads to microbiological spoilage are E. Coli bacteria, Lactic acid bacteria, Acetic acid bacteria, Alicyclobacillus spp., yeast and molds [2,3]. Therefore, only rinsing of the bottles is not sufficient in case of used RGBs, but bottle needs to be cleaned by means of an alkali solution (or washing compound) at a certain temperature for the sanitation of the bottle, which is ensured by the bottle washer machine [3].

Keywords—Bottle Washer Machine; PID (Proportional Integral Derivative) Control; PLC (Programmable Logic Controller); RGB (Returnable Glass Bottle); RTD (Resistance Temperature Detector); SSR (Solid State Relay); Washing Compound

I.

The bottle washer machine should be automated such that it will produce glass bottles, which will be free of pathogenic and virulent beverage harming germs, free of decoration residues, odorless, bright and clear, free of chemicals, and will provide adequate temperature for filling and should also be drip free [1].

INTRODUCTION

In beverage filling and packaging industry, various types of machines are used to carry out the beverage filling and packaging process. However, some variation in terms of machines is possible depending upon the type of container used to carry the beverage in the beverage filling and packaging line. Mainly, three types of containers are used to carry the beverage: (1) RGB (Returnable Glass Bottle), (2) PET (Polyethylene terephthalate) bottle, and (3) Can.

Before supplying the cleaned bottles for the filling operation from the bottle washer machine, it is necessary to check the absence of the washing compound inside the bottle. Phenolphthalein is used as a chemical agent to determine the absence of the washing compound [1]. If the color of Phenolphthalein gets changed, the chemical composition of the washing compound and the bottle cleaning process inside the machine should be reviewed. To ensure the bottle quality

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2015 International Conference on Advances in Computer Engineering and Applications (ICACEA) IMS Engineering College, Ghaziabad, India

and appropriate beverage filling and packaging operation, the bottles are supposed to pass through the bottle defect detection system after the discharge section of the bottle washer machine [4].

drain the rinse water before discharging from the bottle washer machine.

The conventional bottle washer machines used for large scale beverage industry are much complicated in mechanical and control aspects and also costly for small scale beverage industry. The bottle washer machine used in large scale industry has the capacity of 10,000 to 1,50,000 bottles per hour [1]. Since, the requirement of small scale beverage industry is small i.e. approx. 1000 – 2500 bottles per hour, this paper proposes the bottle washer machine for RGBs which provides a cost-effective bottle washing solution for beverage filling and packaging line.

Fig. 1. Block diagram of bottle cleaning process

The jetting inside and outside the bottle gives the rubbing action to remove soil and dirt. Alignment of the overhead sprays with the mouth of the bottle is necessary to effectively remove dirt and molds from the inner surface of the bottle. The sprays entering the inner surface of the bottle give an equal heating and cooling to the bottle and it will minimize the thermal shock in the bottles.

II. DESIGN AND WORKING OF BOTTLE WASHER MACHINE The bottle washer machine comprises of various treatment zones through which RGBs are passed. The block diagram of bottle cleaning process is shown in Fig. 1. The used RGBs are passed to the infeed section of the bottle washer machine by conveyor belts. From the bottle infeed table, the bottles slide on slate chain and get transferred onto the plastic cam fixed on the hollow shaft connected through timing infeed gear mechanism. The bottles are transferred from the plastic cam to the bottle pockets on bottle pocket carriers. The bottles are passed through different treatment zones for pre-cleaning, pre-heating, cleaning, rinsing and fresh water spraying operation as shown in Fig. 1. The discharge section of the bottle washer machine does have the gear mechanism similar to the infeed section of the bottle washer machine.

The correct temperature of the washing compound in combination with time and chemical composition is a paramount parameter to have the best quality washing. The mold will be eliminated by the extra high temperature (≥ 85 °C) of the washing compound. Bottle cleaning cannot be effectively accomplished by reducing the temperature and increasing the caustic soda concentration and vice- versa. The correct combination of the temperature and chemical composition is the parameter of utmost importance. Temperature must be controlled in the different treatment zones to avoid the thermal shock in the bottles, which may cause the bottle breakage (The difference between two subsequent treatment zone should not be ˃ 35 °C).

The factors affecting the bottle cleaning process and working of the bottle cleaning process are as below:

B. Different treatment zones of Bottle Washer Machine The bottle washer machine has different treatment zones namely: (1) Pre-heating zone, (2) Caustic zone, and (3) Hydra zone. The design of bottle washer machine and different treatment zones has been created on the Creo software platform as shown in Fig. 2.

A. Factors affecting the bottle cleaning process The factors affecting the bottle cleaning process are: (1) Chemical treatment, (2) Time, (3) Mechanical treatment, and (4) Temperature. Correct chemical composition and concentration are important parameters for bottle cleaning. Caustic soda is an aggressive sterilizing alkali that react with soils to form soluble salts and it does not have soil suspending power, which will lead to re-deposition of insoluble compounds in the bottle. Caustic soda is also difficult to rinse without additives. Caustic soda alone cannot prevent the formation of foam and scale [5]. Therefore, caustic soda needs to be used along with defoamers, hardness stabilizers, disinfectants and additives as a washing compound.

The caustic zone and hydra zone are filled with the washing compound and fresh water up to the upper limit of the tanks respectively, controlled by solenoid operated valves at the respective inlets. The caustic zone and hydra zone are heated by the heater up to 85 °C and 55 °C respectively. Afterwards, the water heated inside the hydra zone will be sprayed in the pre-heating spray, hydra spray, and caustic spray (located in pre-heating zone, hydra zone and caustic zone respectively) which will be supplied by the pump. The fresh water will be supplied to the fresh water spray in the preheating zone and hydra zone respectively, which will be controlled by solenoid operated valves.

A certain amount of time is required to heat up the bottles and cool down for the beverage filling operations. Time considered is the time required for the caustic soda to penetrate the bottle, spray inside the bottle to remove the dirt and mud, bottles and bottle carriers drain off the washing compound before the next treatment zone and completely

The used RGBs are transferred to the bottle pocket carriers. The bottle pocket carriers are mounted on the chain

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2015 International Conference on Advances in Computer Engineering and Applications (ICACEA) IMS Engineering College, Ghaziabad, India

Controller) as shown in Fig. 3, since the use of the PLC provides quite flexible control as well as provides real time and accurate control [6].

and gear mechanism, which will move the used RGBs in different treatment zones.

The list of manipulated variable, controlled variables and type of measurement signals associated with respective treatment zones has been given in Table I. The level in the pre-heating zone, caustic zone and hydra is sensed by limit switches since the process requires the detection of high and low level only [7].

Fig. 2. Design of bottle washer machine and different treatment zones

The used RGBs are firstly passed through the pre-heating zone in which the bottles are sprayed with the fresh water sprays, having temperature of the water at room temperature and subsequently, used RGBs are sprayed with pre-heating sprays having temperature of water at 55 °C. This will remove the dirt and beverage residues from the RGBs. Afterwards, bottle pocket carriers will be passed through the caustic zone, which will soak the used RGBs in washing compound solution having temperature of 85 °C. This will result in the elimination of dirt residues and microbes. The caustic spray at the end of the caustic zone will spray the hot water inside the bottle, which will ensure that the minimum caustic soda is carried over in the hydra zone [1]. The bottle pocket carriers are then passed through hydra zone, which does have hydra spray and fresh water spray having temperature of water at 55 °C and room temperature respectively.

Fig. 3. Siemens S7-317-2-PN/DP PLC setup

The limit switches are interfaced with the Siemens PLC and provide the input in terms of 24 V DC. The level control for each treatment zone is achieved by means of 24 V DC operated solenoid valves in conjunction with the output of the limit switches. The list of controller, sensors and instruments specification used is listed in the Table II. The temperature control for caustic and hydra zone is achieved using IFM TA-3430 Pt1000 two wire Resistance Temperature Detector (RTD) sensor, SSR (Solid State Relay) and heater which operates on 230 V AC. The Pt1000 RTD sensor has a working temperature range of 0 °C to 140 °C, which is well enough, since the maximum required temperature is 85 °C for the bottle cleaning process.

To prevent the water transferring from pre-heating zone to caustic zone, higher limit switch will be provided. When the higher level is detected by the high limit switch in the preheating zone, the solenoid valve of the drain pipe will get opened, preventing the transfer of water into the caustic zone. The overhead of the caustic zone has been kept in such a manner that the water accumulated inside the caustic zone does not get transferred to a neighboring zone for one washing cycle. However, for safety reasons higher limit switch is provided. Upon detection of the high limit switch of the caustic zone, the washing operation will be stopped.

An alternative temperature sensor which can be used is the thermocouple. Since, the thermocouple is costly, has less measurement speed, less stable and not linear throughout the range compared to RTD and as it also requires cold junction compensation; RTD is a better choice for temperature control in bottle cleaning process. RTD also has excellent repeatability, high immunity to electrical noise and more stable.

The sedimentation tank of caustic soda is provided besides the machine, which will supply the amount of caustic soda necessary to for each washing cycle. The water reservoir is also provided to supply the amount of water required for each washing cycle.

The unison zero crossing type SSR operates on 24 V DC and switch the 230 V AC supply to the heater. The advantage of using SSR is that it can be easily operated for on/off control as well as PID control application, since the mechanical relay and single phase contactor cannot be used for extremely fast switching in PID control application.

III. SYSTEM HARDWARE STRUCTURE The bottle washer machine has been automatized using Siemens S7-317-2 PN/DP PLC (Programmable Logic

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2015 International Conference on Advances in Computer Engineering and Applications (ICACEA) IMS Engineering College, Ghaziabad, India TABLE I.

LIST OF CONTROLLED VARIABLES, MANIPULATED VARIABLES AND TYPE OF MEASUREMENT SIGNALS ASSOCIATED WITH RESPECTIVE TREATMENT ZONES

Type of treatment zone

Controlled variable

Manipulated variable

Type of measurement signal

Output flow of the drain pipe

Digital

IV. SYSTEM SOFTWARE DESIGN The programming of the Siemens S7 series PLC has been accomplished in the SIMATIC Manager software. The Siemens S7 series can be programmed in three different programming languages, namely ladder logic, STL (statement list), and FBD (Function Block Diagram). The ladder logic has been used for the programming of the PLC, for the bottle washer machine.

Low level

Preheating zone

The flowchart of the logic sequence of the bottle washer machine is shown in Fig. 4.

High level

Low level

Input flow of the caustic zone

Digital

High level

Input flow of the caustic zone

Digital

Temperature

Input PWM of the heater of the caustic zone

Analog

Low level

Input flow of the hydra zone

Digital

High level

Input flow of the hydra zone

Digital

Temperature

Input PWM of the heater of the hydra zone

Analog

Caustic zone

Hydra zone

The three phase induction motor is powered by 440 V AC and is interfaced with the Siemens PLC through the three phase Siemens contactor, which will drive the chain and gear mechanism. TABLE II.

INSTRUMENTS AND SENSORS USED IN BOTTLE WASHER MACHINE

Instrument/Sensor

Input supply

Output

PLC

24 V DC

4 – 20 mA / 24 V DC

Limit switches

24 V DC

24 V DC

Pt1000 RTD (IFM TA3430)

24 V DC

4 – 20 mA

SSR (Unison 801 ZDA 48 50 01)

4 – 32 V DC

24 – 480 AC

Heater

230 V AC

Heating Energy

The limit switches, SSRs, solenoid valves, a three phase contactor and a single phase contactor (for pump) have been interfaced with digital I/O modules of PLC and the Pt1000 RTD sensors have been interfaced with the analog module.

Fig. 4. Flowchart of logic sequence of the bottle washer machine

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2015 International Conference on Advances in Computer Engineering and Applications (ICACEA) IMS Engineering College, Ghaziabad, India

A. RTD configuration in SIMATIC Manager The Pt1000 RTD sensors are interfaced as two wire current wire transducers as shown in Fig. 5. The scaling of the working temperature of the Pt1000 RTD sensors has been done in the program logic. Therefore, the actual value of the temperature of the hydra and caustic zone can be acquired.

the steady state error, but makes transient response worse. The combinational action of the proportional, integral and derivative terms provides system stability, reduces the overshoot and improves the transient response [9]. By tuning the three terms of PID algorithm, it can provide desired control action for different requirements [10].

B. Temperature control schemes There are mainly three types of temperature control schemes: (1) On – Off Control, (2) Differential Gap Control (On-Off Control with Dead band), and (3) PID Temperature control.

C. PID temperature control for caustic and hydra zone The PID temperature control for caustic and hydra zone has been implemented by using the PID temperature control algorithm of the Siemens PLC for caustic zone and hydra zone respectively as shown in Fig. 6.

Fig. 6. PID Temperature con...