CIP Heat Exchangers

Hold the tank warm and trim in line; pick one only when the skid forces it. A tank held at 140 F between circuits cuts the in-line duty from the full 50 degree rise to a 30 degree trim: at 200 gpm that is 3 million Btu/h instead of 5 million, and the steam valve drops a size with it. Tank-only heating suits a recirculating skid with 20 minutes or more between circuits; in-line-only heating is forced on single-use skids and one-pass dosing systems, where there is no warm solution to start from. The sign that a plant chose wrong is the first circuit of the shift running two or three minutes over because supply temperature is still climbing while the timer is already counting. Tell us the circuit sequence and the gap between circuits and we size both heaters, or confirm that one is enough.

Yes for rinses and the acid step; for 170 F caustic it works only with a much larger exchanger. A 190 F hot water supply cooled to 150 F against solution rising from 120 to 170 F gives a log mean temperature difference near 25 degrees; 15 psig steam at 250 F gives about 100 on the same duty, so the hot water heater needs roughly four times the area to match the ramp. A gasketed plate keeps that area affordable. The failure mode is a loop whose supply sags to 175 F when the pasteurizer draws, leaving caustic parked at 165 F with nowhere to go. Send the loop's supply temperature at its worst hour, not its setpoint.

Peroxide-cured EPDM, and the cure matters as much as the polymer. Sulfur-cured EPDM hardens and cracks sooner under repeated hot caustic, while FKM, the usual choice for acids, swells and loses strength in 2 percent sodium hydroxide at 170 F. On a U-tube heater the compound sits only in the head gasket; on a gasketed plate it lines every channel, so a plate on a full CIP program is bought with a spare gasket set and a replacement interval in mind. Chlorinated alkaline cleaners and any solvent flush move the choice toward PTFE-envelope gaskets. List every chemical in the program, including the one used twice a year.

Control on the heater outlet; verify on the return. The outlet RTD runs the steam valve because it sees the result of a valve move in seconds, while a return RTD sees it only after the solution has traveled the whole circuit, and a loop closed on that delay hunts for the entire wash. The return RTD is the one the cleaning record keeps, so the supply setpoint is carried 5 to 10 degrees above the required return temperature to cover loss along uninsulated pipe and through the equipment being cleaned. One RTD doing both jobs on the supply line proves only that the heater worked, not that the spray ball saw 170 F.

It takes a quarter of a 150 hp boiler the instant the valve opens. A 150 hp boiler makes about 5,175 lb/h, and the 1,300 lb/h a 20 minute heat-up demands arrives as a step, so header pressure drops and the HTST or evaporator on the same main sees its own steam valve swing wide. Three fixes: hold the tank warm with the small recirculation heater so the step shrinks, stagger CIP starts against production draws, and ramp the valve open over a minute or two in the sequence. Give us the header pressure at the skid under full production load.

No. Peracetic and most no-rinse sanitizers are dosed at ambient, and heating them speeds decomposition and attacks the seals. The practical issue is the heater's own heat: the shell of a 170 F caustic heater and the solution left in it keep the first sanitizer through at well above label temperature unless the sequence closes the steam valve and runs the final rinse long enough to cool the metal. A hot water sanitize step is the exception and is quoted as a separate duty with its own temperature and hold.