DeLaval Cleaning Solutions National Customer Training Session Dave Gebhart. August 2011

Transcription

1 DeLaval Cleaning Solutions National Customer Training Session Dave Gebhart August 2011

2 Course Objective Teach basic Clean In Place philosophies and techniques so engineers, designers, and operators will have a working understanding of CIP and be able to apply these to CIP operations in their facilities.

3 Course Topics What is CIP? What makes equipment CIP able? What are the common CIP chemical use programs? What is required to document CIP usage? What are the common CIP equipment configurations? What are some types of CIP systems? How to review recording charts.

4 Automated CIP Cleaning What is CIP? CIP = Clean In Place a method of cleaning process equipment without the disassembly of equipment parts it involves: Spray clean large volume tanks and duct work. Flow clean piping Removal of product residues Little manual intervention

5 History of CIP The first dairy plants to apply automated in-place cleaning to an extensive degree were placed into operation in 1960, with considerable equipment in those early operations still being manually cleaned.

6 3A Sanitary Guidelines All CIP piping is to be constructed of stainless steel or glass with CIP type connections. Clamp-type fittings and connections are used for semipermanent connections to allow for proper sealing. Proper pitch and alignment for piping layout (1/4" per foot). Limited number of gaskets due to reliance on welded connections and to assure that joints will CIP clean. Five 5'/second (FPS) for cleaning piping circuits. RTD recorder for the return line temperature. Alkaline solution followed by an acid wash.

7 CIP Advances Resulted In Increases in the sizes of processing and storage tanks as compared with vessels that had to be manually cleaned. Significant increase in processing flow rates and packaging machinery capacity. Reduction in manual cleaning practices. Uniform cleaning over all surfaces and conformity to cleaning requirements. Reduction in potential for cross contamination of product. Reduction of potential operator interface error.

8 Why CIP? Safety advantages: Eliminates the need for plant personnel to enter vessels and other processing equipment. Eliminates the handling of cleaning solution. Productivity advantages: Automated systems help reduce overall downtime of process equipment. Reduces overall cost associated with manual cleaning. Reduces overall cost of product loss. Allows personnel to reallocate time to increase productivity.

9 CIP Basic Requirements CIP circuit to clean (vessel or line). Line Circuit CIP supply tank. CIP supply pump. Vessel Drain valve or return pump.

10 Automation of Cleaning Through CIP Does not imply pynon-human involvement CIP circuits must be checked to determine return flow and the correct operation of pumps and valves. The temperature and concentration of cleaning compounds must be correct. All factors that influence sanitation must be validated and are only as effective as the individual that controls or monitors the system.

11 In Most Modern Facilities Cleaning is automatically controlled by the CIP system Cleaning is carried out at temperatures from 135 to 150 F and higher. The CIP system must be able to heat the solution and maintain the temperature. When only one CIP system exists, one must size the CIP tanks for the circuit that requires the greatest volume. The system must also be designed to handle the most difficult soils and worst case scenario. In many instances, this means that cost efficiencies are lessened and two or more small systems would pay for themselves.

12 What is Required to Document CIP Systems? Industry regulations, vary but in general you need: Return temperature recorder (only item required by 3A). Supply pump p discharge pressure recorder. Supply flow rate record (flow meter). Return flow rate record (flow meter). Return conductivity record. Supply conductivity record. As an option a data collection system may be used.

13 CIP Systems Are Designed to Perform Two general categories of cleaning Spray cleaning of vessels like tanks and silos. Line circuits or similar closed circuits such as heat exchangers.

14 General Recommendations for Proper CIP Operation Return lines from vessels should pitch to the return pump inlet. Vessels should pitch to the outlet t valve to ensure proper drainage and return. A pitch of ¼" per foot toward the outlet, plus locating the outlet 20" to 24" above the floor is recommended. Return flow valves should control only one tank. Each spray device must be designed for the particular soil and general needs of that individual tank. Pressures and volume should be checked on each tank to ensure proper coverage and return. All tanks must be vented for protection from collapse.

15 Conditions for Good CIP Cleaning A CIP pump should be available to provide a minimum of a 10% increase in flow of cleaning solution over the product capacity. The CIP pump should provide a flow of solution to achieve a minimum velocity of 5'/second /second. This can be determined by the chart below. Normal Size Ft Velocity P SFt. Per Sec. Flow G.P.M. Fill 10 Gal. Can 1" seconds 1-½" seconds 2" seconds 2-½" seconds 3" seconds 4" seconds

16 Engineering a CIP System It s the efficient coordination of a PLC controller: Operating properly sized equipment in a proper sequence. Delivering a pre-calculated detergent solution at an efficient temperature and sufficient flow rate. Processing gparameters must be considered in conjunction with the design of the CIP system. Calculations often times based on the worst case scenario. What does the customer wish to accomplish?

17 Many Variables Must Be Product Considered control valves and for their a properly effect on functioning CIP. CIP system Pipe size. What are the soils? What detergent is the best selection? How many circuits and time frame? Circuits it cleaned independently d or simultaneously? l Valve sizes and locations. Pump sizes and locations. Since design requirements vary, most CIP systems are custom designed for each plant.

18 CIP Cleaning of Equipment Cleaning and disinfecting techniques and economic pressures have accelerated automation of the cleaning operations. The following terms are used to define the degree of cleanliness: Physically y clean removal of all visible dirt from the cleaned surfaces. Chemically clean removal of all visible dirt as well as microscopic residues. Bacteriological cleanliness obtained by disinfection that kills all pathogenic bacteria and most other bacteria. Sterility destruction of all micro-organisms. organisms In all food industry cleaning operations, the objective is to achieve both chemical and bacteriological cleanliness.

19 CIP Cycle Development Process The building blocks for your CIP cycle will be dependent on: Equipment being cleaned. Spray devices being utilized. Water types used for cleaning. Chemicals used for cleaning. Temperature limitations. Soil to be cleaned.

20 CIP Basic Cleaning Sequence 4-Step CIP Cleaning Cycle Pre-Rinse Chlorinated Cleaner Wash Post-Rinse 6-Step CIP Cleaning Cycle Pre-Rinse Alkali Wash Post-Rinse Acid Wash Acid Sanitizer Post-Rinse This type of cleaning is normally done on cold processed vessels, tanks, and silos. Sanitize This type of cleaning is done on cook vats, HTST, UHT, and other high-heat systems.

21 Typical CIP Cycle CIP example cleaning sequence Step Time Temp Step Description (Minutes) ( F) Detergent 1 Pre-rinse none 2 Detergent Wash % 3 Fresh Rinse none 4 Acid Wash ½% 5 Fresh rinse 5 70 none 6 Sanitize 4 none none 7 Air Blow to Drain 4 none none

22 Cleaning Cycle Cleaning operations must be performed strictly according to procedure. The sequence must be exactly the same every time. The cleaning cycle normally comprises the following stages: Recovery of product residues by means of scraping, drainage, and forcing out with water or compressed air. Pre-rinsing with water or recovered solution in order to remove loose dirt. Cleaning with detergent. t Post rinsing with clean water. Sanitizing / Disinfection by means of heating or with chemical agents. Each stage requires a certain length of time in order to achieve an acceptable result. It is not possible to save time by omitting a step or by shortening the cycle.

23 Typical CIP Cycle Pre-rinse Pre-rinse with water to drain. Typical 15 to 45 seconds to rinse gross soil to drain. Tank circuits may require bursting of the CIP supply to eliminate bathtub ring effect. Cycle may be programmed longer depending on soil condition to be cleaned and spray device being used.

24 Typical CIP Cycle Wash cycle: Re-circulate wash solution of detergent at desired concentration and temperature for 5 to 45 minutes depending on soil. Hold step time for return temperature and chemical concentration. Will loosen and place remaining soil in suspension. Length of cycle is dependent on soil load, spray devices, flows, pressures, drain sizes, heat-up time, and chemicals being utilized during this step.

25 Typical CIP Cycle Post-rinse: Rinse with fresh water to flush cleaning detergent from system for 15 to 45 seconds. Tank circuits will require bursting of the CIP supply. Overall time will be dependent on drain rate, size and location of equipment to be cleaned, and CIP system location.

26 Typical CIP Cycle Acid wash: Re-circulate acid solution at desired concentration and temperature for 5 to 10 minutes. Hold step time for return temperature and chemical concentration. Acid is not always necessary depends on application. If used, it can help neutralize alkaline detergent. Occasionally, a specific acid wash is recommended to provide passivation of stainless steel equipment.

27 Typical CIP Cycle Final rinse: Rinse system with pure water repeatedly until rinse water approaches final rinse conductivity set point. Rinse on a once-through basis.

28 Typical CIP Cycle Sanitize Fresh rinse water is injected with chemical. Metering pump adds proper concentration. All surfaces must be thoroughly wetted. Each sanitizer type needs a residence time (usually 2 minutes of contact time). Cycle should allow for drain time. Sanitize just prior to process start. Some chemicals are extremely corrosive.

29 Typical CIP Cycle Air blow to drain: Blow filtered air (0.2 micron filter) through CIP supply line to speed draining process and remove water from low points such as flow panel U-bends. Air blow is on a once-through basis to drain.

30 Principles of Cleaning Apply for CIP PRE-RINSE 1. Removes 90% of Loose Soil 2. Cold to 102 F TIME (minutes) 1. Total Cleaning Time 2. Time to Disassemble & Assemble CHEMICAL CONCENTRATION (%) 1. Soil Load 2. Carrying Capacity 3. Rinsing Properties MECHANICAL ACTION (psi / physical energy) 1. Flow 2. Velocity 3. Mechanical Pressure TEMPERATURE (F ) 1. Heat Supply 2. Heat Loss

31 Pre-Rinsing With Water Pre-rinsing should be carried out immediately after the production run to prevent drying of soil. Pre-rinse with warm <110 F water. Pre-rinsing should continue until the water leaving the system is clear. Any remaining soil will increase the detergent consumption. At least 90% of non burned-on residues normally 99% of the total residues may be removed by means of efficient pre-rinsing.

32 Cleaning With Detergent A number of variables must be carefully controlled in order to ensure satisfactory results with a given detergent solution. These are: Choice or selection of chemical determined by soil to remove. The concentration of the detergent solution. The temperature of the detergent solution. The mechanical effect on the cleaned ed surfaces. The duration of cleaning.

33 Detergent Concentration The amount of detergent in the solution must be adjusted to the correct concentration before cleaning starts. During cleaning some neutralization of the cleaning solution takes place during cleaning. Check the concentration during cleaning and adjust if necessary. Checking can be either manually or automatically done. Target concentration should be according to the supplier s cleaning procedure. Increasing the concentration may not improve the cleaning effect. Using too much detergent simply makes cleaning needlessly expensive.

34 Chemical Addition Chemical addition equipment Manual Auto-feed pumps Peristaltic (Knight) Piston (FMI) Diaphragm (Wilden) Level monitors Level switches Sonic sensors Conductivity sensors

35 Concentration Control Concentration control: Conductivity based Meter / timer based

36 Concentration Control Conductivity-based chemical addition Advantages: Monitors chemical strength and maintains strength. Provides documentation of chemical usage. Can greatly improve efficiency through reduction in water and chemical usage. Disadvantages: Requires maintenance of equipment. Capital cost for chemical addition equipment.

37 Concentration Control Timer- or meter- based chemical addition Advantages: Simple. Inexpensive Disadvantages: Chemical strength th will vary between CIP cycles. Reduction in efficiency.

38 Detergent Temperature The temperature should be controlled and monitored during the cleaning cycle in order to ensure that it does not deviate from this optimum level. The temperature RTD s are usually located in the return line and record CIP return solution temperature. Most CIP systems have a delay to temperature programmed in.

39 Heat Supply May be accomplished through several different ways Tube N Shell Heater Advantages: Very efficient. Easy to control. Very little wash delay. Disadvantage: Expensive. Direct Steam Injection Advantage: Relatively inexpensive. Disadvantage: Not very efficient. Extended wash delay.

40 Mechanical Cleaning Effect In manual cleaning, scrubbing brushes are used to produce the required mechanical scouring effect. In mechanized cleaning of pipe systems, tanks and other process equipment, the mechanical effect is supplied by hydraulic action. The detergent is pumped at higher capacities than the product pumps with minimum flow velocities of 5'/second in the pipes. pp At these velocities the liquid flow is very turbulent. This results in a very good scouring effect on the surfaces of the equipment.

41 Possible Break Here Review what we covered. Review what is to come..

42 Action Effects Manual scrubbing Spray cleaning: CIP spray static vs. dynamic spray. High pressure. Wash tunnel, rack, and vat washers. Turbulence: Immersion COP and stick washers. Circulation through piping systems.

43 For CIP Spray Cleaning Spray system, tees, spray balls, dispersion plates and the like may be permanently installed and have numerous advantages: Generally few, if any, moving parts. Made from stainless steel. Minor fluctuations and variations in supply will have little affect. A proper installation should last for an extended period of time. Proper installation of the return systems to the supply tank is of utmost importance.

44 3A Sanitary Requirements for Static Spray Balls Cleanable and inspectable. Self-cleaning joints and clips. Free-draining. Location and hole pattern is important. Finish of 150 grit or greater. Should be installed above product zone.

45 Dynamic Spray Device Advantages: Direct t impact cleaning of all surfaces. Low volume. Disadvantages: Removal after use. Cost initial investment and maintenance.

46 CIP Spray Principle Cascade water down interior surfaces: Spray devices installed in tank. Needs to be installed above product line. Spray ball flow rates dependant on tank diameter. Return pump often used to return solutions from tank outlet. t Air eliminator used to remove air from centrifugal return pumps.

47 CIP Spray Operation Shadowing: Top view of tank with baffles and agitator showing shadowing of spray due to obstructions within the vessel. Red areas are not effectively cleaned. Multiple spray sources are required to overcome shadowing caused by baffle plates, agitators, etc. within the vessel.

48 Duration of Cleaning Depends on the following: Soil type Fats, proteins, minerals Process temperature The higher the process temperature the longer the time required Soil amount The heavier the soil load the additional time required Time availability Must consider the costs of electricity, heating, water and labor Equipment being cleaned In the case of membranes, longer wash steps do not always improve cleaning

49 CIP Functions In order to complete a CIP program, a series of steps, or functions, are required. Each step activates the desired CIP system components required to carry out that function. For example, the fresh water rinse function would activate the water valve, the supply tank outlet valve, the CIP pump, and supply fresh water to the circuit being cleaned.

50 CIP Example Cleaning sequence (pin chart) CIP Chart - Tank Program Single Use - Solution Recovery x = Active / On Function Value Supply Tank Supply Tank Fresh Return Recovery Recovery CIP Steam Return Drain Alkaline Sanitizer Outlet Inlet Water Check Tank Tank Supply Valve Pump Valve Feed Pump Valve Valve Valve Probe Outlet Return Pump Pump Valve Valve Rinse - Fresh Water 40 sec. x x x Drain To Sewer 60 sec. x x Return Check x x x Rinse - Recovered 25 sec. x x x x Drain to Sewer 45 sec. x x Rinse - Recovered 25 sec. x x x x Drain to Sewer 45 sec. x x Pump Down 50 sec. x x x Est. Circulation 10 sec. x x x Steam On 140 F x x x x Add Alkaline Det. 37 sec. x x x x x Delay to temp. 140 F x x x x Circulate - Wash 18 min. x x x x Steam Off - Circulate 2 min. x x x Drain To Recovered 60 sec. x x x x Rinse - Fresh Water 45 sec. x x x x Drain To Recovered 60 sec. x x x x Rinse - Fresh Water 45 sec. x x x x Drain To Recovered 60 sec. x x x x Pump Down 50 sec. x x x Est. Circulation 10 sec. x x x Add Sanitizer 21 sec. x x x x Circulate Sanitizer 3 min. x x x Drain To Sewer 60 sec. x Shut Down

51 CIP Functions Sample functions (controlled by PLC): Rinse with fresh water (can be COW or permeate water). Check for return using in-line probe. Rinse recovery of solution. Drain to sewer. Drain to recovery tanks. Pump down. Delay to circulation is established.

52 CIP Functions Sample functions (cont.): Level control Delay to temperature Chemical injection Chemical circulation (acid and/or alkaline) Delay for chemical addition or delay to solution strength Chemical recovery Sanitizer circulation Final rinse and shut down Air blow for solution recovery

53 Single-Use System The solutions are pumped into the process and returned back to the CIP system for re-circulation back into the process again. All cleaning solutions and rinses are used once, then discharged to drain. Cleaning strategy easily alter chemical types and strengths.

54 Re-Use Re-circulation Design All or some of the cleaning solutions are saved for re-use on the next cleaning cycle. Used where cross contamination ti is not likely. l Re-use systems are well suited for applications where cleaning is performed frequently. Very economical to operate.

55 Re-Use Re-circulation Design Requires a separate tank for each solution to be saved, plus a fresh water tank. CIP tanks holding saved solutions are sized for the hold-up volume of the largest CIP circuit. Multiple-tank re-use systems are well suited for applications where cleaning is performed frequently. Permanent or fixed installation. Portable designs are not practical due to weight and size of unit.

56 4-Tank Recovery / Re-Use CIP Higher initial capital cost. Recover most chemical per cycle 80%. Recover large volume of water. Reduce utility cost by saving heated solution. Save time by reducing delays from charging system. Savings gained every cycle, every circuit, every day!

57 4-Tank Re-Use System Utility inputs & drain

58 Step #1 Pre-rinse to drain Recovered rinses are re-used to flush soils from process tubing/tanks Steam tempers the system

59 Step #2 Detergent wash Caustic is re-circulated Caustic make-up (losses only) Heat process circuit and caustic depression

60 Step #3 Detergent recovery Rinse recovered with residual caustic Top off detergent tank first, then recover remainder rinse for future pre-rinse

61 Step #4 Acid wash Acid re-circulated Acid make-up (losses only) Heat process circuit and acid depression

62 Step #5 Acid recovery & rinse to drain Rinse recovered with residual acid Acid tank topped off Remaining rinse to drain

63 Step #6 Sanitize

64 Single-Use vs. Re-Use Single-Use Reduced possibility for cross contamination, as new cleaning solutions are made up for each cleaning cycle, used once, and then discarded. Less floor space required, as there are smaller and fewer tank(s). Higher water, heat, and chemical usage than a reuse design. Slower overall wash cycle time than a re-use design, as solutions are heated and charged with chemical for each wash. Less expensive to purchase than re-use systems having multiple tanks and additional valves. Re-circulation tank on CIP system must be rinsed clean during operation prior to the next step in the cleaning cycle. Re-Use Higher risk of cross contamination as common cleaning solutions will be used for all product soils. Larger floor space required, as tanks must be accurately sized to hold-up volume of largest cleaning circuit. Future needs must be taken into account. Lowest water, heat, and chemical usage of all designs. Faster overall wash cycle time than a once-through or single-use design, as recovered solutions are already heated and charged with chemical, and tanks do not have to be rinsed between steps. Higher purchase price due to added tanks and valves.

65 Re-circulation Return Methods Three common methods of returning CIP solutions: Centrifugal return pump Liquid ring return pumps Eductor / eductor-assisted return

66 Centrifugal Return Pumps Most common type of return. May be applied to a wide variety of cleaning applications and operate at very high flow rates and distances. Low-speed motor used to reduce NPSH requirements. Pumps must be sized to return flow at a greater rate than the CIP supply to maintain system balance.

67 Centrifugal Return Pumps Advantages: May be made portable allowing one pump to be used for several circuits. Capable of high flow rates. Least expensive. Disadvantages: High NPSH required. Not self-priming. Requires air relief valves to prime pumps or eliminate air in system.

68 Liquid Ring Return Pumps Similar to centrifugal pumps, but they are capable of pumping air/water solutions. Liquid ring pumps are capable of pulling a suction lift of up to 23'. Elimination of the problems associated with centrifugal pumps.

69 Liquid Ring Return Pumps Advantages: Self-priming priming. Minimizes hydraulic problems. May be made portable allowing one pump to be used for several circuits. May be located at the CIP system in many applications. Disadvantages: Higher cost than centrifugal pumps. Requires water in the casing to form a liquid ring.

70 CIP Operation Things to Check Tanks & Silos Before CIP refrigeration must be turned off. Adequate pre-rinserinse with most soil removed? Is supply pump operating properly? Shaft seal worn, impeller damaged, obstruction in supply line? Proper program with burst rinsing and rinse removal? Air-operated valves operating properly? Fittings on suction side of return pump tight with gaskets? Wash cycle with proper hydraulics and correct chemical concentrations? Correct post-rinse and sanitizing steps? Visual inspection.

71 CIP Preparation Tanks & Silos Air-agitating assemblies disassembled and hand cleaned. Sample cocks removed and brush washed. Door gaskets removed and brush washed. Sight gaskets and vent covers removed and brush washed. Agitators removed and brush washed. Agitator sleeves brush washed. Are all parts removed and brushed washed?

72 CIP Operation Things to Check Line Cycles Pump solution through lines with sufficient velocity to create turbulent flow. Velocity should be 5'/second or greater. Eliminate dead legs in piping. Can t be more than ½ of the pipe diameter Pulse process stem valves properly to clean seats and O-rings. Pre-rinse adequate to remove all product soil from line? Correct temperature? Proper chemical concentration? Post-rinse must be adequate to remove all wash solution. Lines cool to the touch? Sanitizing step with two minutes contact.

73 CIP Preparation Line Cycles Plug valves removed, brushed, washed, rinsed, sanitized, lubed, and replaced. Air valves validated d for proper cleaning and maintenance. All product pumps in the circuit need to be disassembled, d brush washed, rinsed, sanitized, and replaced. All dead ends removed and brush washed. All threaded fittings in the CIP circuit need to be disassembled, brush washed, rinsed, and reassembled.

74 CIP Process Lines Valve Sequencing Valves must be cleaned and sanitized throughout the plant. Improper cleaning and maintenance is one of the top contributors to quality issues. All valve surfaces, seats and stems must be cleaned and sanitized. To clean CIP-cleanable valves, they must be opened and closed (sequenced) during the CIP program.

75 CIP Process Lines Valve Sequencing Basic rules for CIP sequencing: Keep flow in same direction. Close valves against the flow. Never change position of three-way valves during flow. Keep it simple. Maintain minimum flow of 5'/second. Adequate rinsing and time to fill the piping in program.

76 Recording Charts Be sure to properly identify each and every cleaning: Anything unusual during cleaning? Item cleaned. Cleaning cycle. Date. Operator. Any identified problems and correction. Post an example of a properly prepared chart.

77 Reviewing Recording Charts Charts have critical information CIP solution not heating quickly: Is refrigeration still on? Excessive water loss? Steam valve malfunction? Low flow or pressure? Condensate line plugged? Temperature controller malfunction? Chart recorder calibrated wrong or wrong chart?

78 Reviewing Recording Charts Charts have critical information Temperature reads too high: Check pen arm. Steam trap or steam valve leaking? Steam valve malfunction? Solenoid stuck open? Temperature incorrect in program? Chart recorder calibrated wrong or wrong chart?

79 Reviewing Recording Charts Charts have critical information Pressure reading higher than normal: Valve malfunction in system? Plugged spray device? Supply pump or impeller changed? Check pen arm. Chart recorder calibrated wrong or wrong chart?

80 Reviewing Recording Charts Charts have critical information Pressure reading lower than normal: Circuit not hooked up properly. Missing spray device? Flow rate from pump is low. Supply pump or impeller changed? Restrictor t missing i or left out? Leaking check ball? Malfunctioning i air relief valve?

81 Ten Commandments for CIP Design I. Remember that water runs downhill. II. It is easier to pump water into a tank than to pump it out. III. Pitch tank CIP connections continuously to pump inlet. IV. Design to close all valves against flow. V. Avoid three-port divert valves like the common plague. VI. Keep tank head nozzles few in number, short in length, and large in diameter, for they are not easy to clean. VII. Locate CIP systems near or beneath the center of CIP loads. VIII. Eliminate all dead ends (branches of more than 1½" pipe diameters), for they will trouble you forever. IX. Pitch all lines to easily opened drain points. X. Design and install supports to eliminate friendly piping that waves when starting pumps and opening and closing valves, for fi friendly systems are short tlived.