Steam condensate recovery

The entire water pump only needs pads with slight temperature resistance. A plain ordinary pump will do. It’s a shame that you’re returning the condensed water to the circulation pool. This condensed water can be used as deionized water. It’s more economical to use it as deionized water.

Reply to 2# renyongchang: If a regular water pump is used, what happens regarding cavitation in the pump when high-temperature condensate enters it? Is a condensate pump needed? Do you all think this plan is feasible? My process generates 3-5 tons of condensed water per hour. What size sink is appropriate? Do you need to stay longer?

Reply to 3# sun1300926: Ordinary centrifugal pumps are not very effective; after being used for a while, they lose their pumping power. When selecting, indicate the temperature; just choose one with a higher temperature tolerance. The main problem is the shaft seal. We have used situations that are very similar. The original design called for steam generated internally by the jacket of the gas generator’s cover (at a pressure of 0.098 MPa) to be fed into the soft water tank, where it circulated before being supplied to the jackets of the cover and the side walls. The pump used is: RBWR50-160 centrifugal pump. (Flow rate: 16.3 m3/h, power requirement: 3 KW, head: 30 m, speed: 2900 r/min, suction lift: 7 m). The shaft seal leaks frequently. Later, I found one with a higher temperature resistance, and that basically solved the problem. Later on, the large cover jacket and the side wall jacket were combined, with steam generated at atmospheric pressure being used for blowing at the bottom of the furnace. Because the pressure is low, there is a lot of condensate. A simple separator was installed on the steam pipe at the outlet, to send the condensate back to the soft water tank. The soft water tank is relatively small, with a diameter of about 2 meters and a height of around 3 meters; the pump is installed at a lower position. It’s a shame that the condensate here goes back to the cooling tower; there is also a problem of \"thermal pollution\".

Reply to 3# sun1300926: Take a look at the fourth floor. Heat-resistant gaskets (for mechanical seals) are sufficient.

If the cooling tower has the capability, the circulating water can first be added to the condensate tank to cool the condensate, and then the cooled condensate can be sent back to the cooling tower. This reduces the requirements for the pump, and it also eliminates the need for one heat exchanger compared to the original proposal.

The steam waste heat (waste steam, flash vapor, condensate) recovery system consists of steam traps, recovery pipelines, recovery pump stations, as well as associated piping, valves, and instrumentation. I. Trap In high-temperature condensate recovery systems, high demands are placed on traps; in addition to their basic function of preventing steam from entering, factors such as drainage capacity and back pressure also need to be taken into consideration. II. Return water network: High-temperature condensate is discharged from thermal equipment in a saturated state; flash vapor inevitably exists in the return water pipes, resulting in a two-phase flow of vapor and liquid. Preventing water hammer and mixing of high and low pressures are key issues in the design of such networks. III. Recovery pump station: The recovery pump station can generally be located in the water treatment area of the boiler room, near where the production equipment is concentrated, or at some point between the boiler room and the equipment that uses steam. Pump stations can generally be installed on the ground surface and do not need to be placed in basements. The entire pump station covers an area of about 7 square meters. A recovery pump station includes: a water collection tank, an anti-cavitation pump set, an automatic control system, a flash vapor utilization system, as well as associated valves and instruments. 1. Water collection tank: The capacity of the water collection tank is generally around 1/3 of the maximum amount of condensate water generated per hour. High-temperature condensate is collected in the collection tank through the check valve under backpressure. The water collection tank is designed to operate under positive pressure, thereby ensuring that the temperature of the high-temperature condensate remains above 100°C and reducing the generation of secondary steam. The water collection tank is equipped with safety devices such as safety valves, level gauges, and pressure control valves. It also has a level control mechanism to regulate the water level inside the tank and to control the start and stop of the cavitation-proof pump. 2. Cavitation-proof pump set: This system is a closed high-temperature condensate recovery system. The condensate water is saturated water; to prevent cavitation in the water pump, a special anti-cavitation device has been designed. This device utilizes the principle of jet boosting to increase the pressure at the pump inlet, thereby addressing the cavitation problem that occurs when centrifugal pumps transport high-temperature saturated water, and ensuring the safe and long-term operation of the pump within its allowable operating temperature range. The pump set is equipped with a self-acting pressure control valve, a manual control valve, and a pressure gauge to regulate and monitor the pressure at the pump inlet and outlet. 3. Automatic control system: The automatic control system of the high-temperature condensate recovery system consists of a level transmitter, an electrical control cabinet, and solenoid valve assemblies, etc. (1) Motor control circuit: A level transmitter installed on the water collection tank is used to measure the water level in the tank; when the level reaches a certain high point, the motor starts up, and the recovery device begins to transport the high-temperature condensed water to the boiler or deaerator. When the water level drops to the low-level control point, the motor stops operating. The device can be set to manual or automatic mode using a selector switch. (2) Water supply circuit: The water supply circuit is used to control the destination of the high-temperature condensate; by means of solenoid valve assemblies, it is possible to supply water to different boilers or deaerators. 4. Flash steam utilization system: To make full use of the heat in flash steam and reduce waste from emissions, jet boosting technology is employed to use high-pressure steam to inject into the flash steam, thereby increasing its pressure for use by low-pressure users. The flash vapor utilization system mainly consists of a steam jet compressor, pressure transmitters, a control system, and associated valves and instruments. When the steam load changes, the pressure transmitter sends a signal to the controller in the control cabinet. The controller processes this signal and outputs a control signal to the electric control mechanism of the steam jet compressor; this mechanism then automatically adjusts the amount of high-pressure steam supplied, thereby ensuring stable pressure at the outlet of the ejector. The recycling system should be equipped with a bypass to ensure greater safety and reliability of the entire system.

A hot water circulation pump can be used for the condensate water. We send the condensate to the boiler for use as make-up water. If the amount of condensate is not too large, it can be directly added to the circulating water network in winter; in summer, cooling is required, unless your cooling tower is designed with a large margin of capacity.

I agree with this view; when I look at the P&ID diagrams in our facility, it shows that the same process is used there as well – industrial water is fed into the condensate recovery tank to be cooled.

It’s a waste to treat the condensed liquid in this way; selling it to other companies would be much more profitable than doing this, especially since it still contains quite a lot of heat

Steam condensate has many uses, but before using it, it is necessary to test its parameters, such as conductivity and chloride ions. If the condensate is used as process water or for deionization, special care must be taken; if the steam heat exchanger in the production process gets punctured, you’ll be in trouble