CIP: The Industrial-Grade Dishwasher

Discrete signals passing from the pin-sheet to the PAC are used as run requests. Devices are assigned a bit position within the sequence word that corresponds to the column assignment for the device. If a device is required to run on a specific step, then its bit position will be assigned a logical “1.” The device is now considered “pinned” and when the logic sequencer executes that step, the bit position is referenced as a run condition for that pump or valve and it is commanded to turn on. If assigned a logical “0” then the condition is not true and the device is not requested to run.

Analog values passing from the pin-sheet to the PAC are used as set points. For example, on a hold for temperature step, the return water temperature set point specified in the pin-sheet is referenced and the actual temperature transmitter is monitored to satisfy that targeted value.

Q: What are some user interface features?

A: The HMI is the primary interface for operations personnel interacting with the CIP process. Figures 2 and 3 show two graphic display screens: The CIP Setup screen and the CIP Overview screen.

The Setup screen provides a means to configure and control the process. Here the operator selects the circuit, can further refine the type of wash, and control the process via start/stop/pause alarm reset and abort buttons. Pertinent status information and alarms are displayed for the user to show what is happening in the process. The cycle name, current step and description, remaining time and started/paused/stopped status are displayed. Additionally, all “hold for conditions” are populated.

The Overview screen is very similar to that found on many process control systems in that the environment is shown through the use of graphical symbols representing the real world devices on the CIP skid. Tanks and their levels, pumps and speed feedbacks, valves, and instrumentation KPIs are displayed and animated accordingly. Navigation buttons to the setup and past cycles screens provide the user with access to the CIP cycle currently running and access to logged data trends on previously cleaned circuits.

Q: How does data collection benefit the CIP system?

A: Simply stated, it closes the loop by using the data already available for purposes of verifying food safety and efficiency. Consider when the production line is being cleaned, it is worse than downtime. It is not just losing money—it is using money. Data collection allows the users to investigate the process and optimize their return on investment.

Most importantly is food safety. Trending the instrumentation KPIs on electronic chartless recorders allows technicians, engineers, and quality personnel to confidently review the CIP for compliance and diagnose areas of concern. Consider, for example, the quality assurance gained in comparing active trends to a previously captured “ideal” trend.

Monitoring the time taken to clean a circuit is merited because it affects the plant’s indirect costs in many ways. Cleaning too long increases labor requirements and challenges production/cleaning schedules. By adding simple time and date stamps, registered at the completion of a CIP run, will ensure the circuit won’t be cleaned prematurely and quality is not short changed.

Usage reports showing the amount of water and chemicals consumed in the process can be investigated so that circuits can be optimized to reduce costs. For instance, strategies can be launched to use the least amount of fresh water necessary, reclaim post-rinses for subsequent pre-rinses, and adjust chemical doses to their desired strengths for proper cleaning. These cost saving efforts also contribute to water treatment as well.

The CIP system has come a long way in recent years with advancements in automation, integration, and data collection. These tools have taken a once self-contained process and enhanced it to become the intelligent system it is today. Because of those combined efforts, CIP systems are handling the most challenging cleaning requirements that industry demands while benefitting from the highest level of performance, quality, and efficiency being offered.